PLASTERING

PLAIN & DECORATIVE

MILLAR

UNIV. OF CALIF. LIBRARY. LOS ANGELES

LIBRARY OF

ARCHITECTURE AND

ALLIED ARTS

Gift of

The Heirs
of
R. Geirmain Hubby, A. I. A,

WIV.

PLASTERING

PLAIN AND DECORATIVE.

INDEX TO ADVERTISERS.

Adie, Patrick

Asbestos and Asbestic Co., Lt. (The)

Batsford, B. T....
Baxter, R., & Co.
BicKLEY, Joseph

Cafferata & Co.

De Jong, F., & Co.
Drew, W. G.

Ford, Peter, & Sons

Gilchrist, Alexr.

Hall, John
Harbutt William
HOBMAN, A. C. ^\'., & Co.
Howe, John, & Co

Illustrated Carpenter and Builder (The)

Jones, Fred., & Co.

L.atto, a. F., & Co.

Mural and Decorations Syndicate, Lt. (The)
Millar, W\

Nelson, Geo., Dale & Co., Lt. ...

Patent Indurated Stone Co., Lt. (The) ...

Robinson, Joseph, & Co., Lt.
Rome, George, & Co.
Rule, John

S.4LTER, Geo, & Co.

Subwealden Gypsum ( o., Lt. (The)

Tyzack, Samuel
Wilson, J., & Son
Young, B., & Co.

TAGE

VII.

XVI.
XIV.

III.

XIII.
XIII.

XIV.

XV.

XII.
XII.

XIV.

II.

XV.

XIV.

XI.
XVI.

XIII.
IX.

V.
XI.

VI.

VIII.
IV.

XV.

XIII.

-.>

'■' * %

NATIONAL T> ^ ^W^

ASSOCIATIONofOPERATIVEPlASTERERS v'l J f "J '' ,' ^' ruppoi

s&l

Ace

PLASTERING

PLAIN AND DECORATIVE.

A PRACTICAL TREATISE ON THE ART & CRAFT OF
PLASTERING AND MODELLING.

INCLUDING FULL DESCRIPTIONS OF THE VARIOUS TOOLS, MATERIALS, PROCESSES,
AND APPLIANCES EMPLOYED; ALSO OF MOULDED OR "FINE" CONCRETE AS USED
FOR FIREPROOF STAIRS AND FLOORS, PAVING, ARCHITECTURAL DRESSINGS, &c. &c.

TOGETHER WITH AN ACCOUNT OF

HISTORICAL PLASTERING IN ENGLAND, SCOTLAND. AND IRELAND,

ACCOMPANIED BY NUMEROUS EXAMPLES.

WILLIAM MILLAR,

PLASTERER AND MODELLER.

WITH AN INTRODUCTORY CHAPTER ENTITLED "A GLIMPSE OF ITS HISTORY,"

Bv G. T. ROBINSON, Esq., F.S.A.

THE WHOLE FULLY ILLUSTRATED WITH FIFTY-TWO FULL PAGE PLATES, AND TWO HUNDRED AND
THIRTY. ONE SMALLER ILLUSTRATIONS (comprising over Five Hundred Figures) IN THE TEXT.

LONDON: B. T. BATSFORD.

NEW YORK:
TRUSLOVE, HANSON & COMBA, LTD.,

67 FIFTH AVENUE.
1899.

Ufbafi Planniag
Utsarf

A PREFATORY NOTE.

> * <

MR MILLAR has asked me to say for him that which he finds somewhat difficult
to say for himself, and I think the simplest way of doing this will be to explain
in the fewest possible words, how and why we made each other's acquaintance and what
came of it. In 189 1 I read a lecture on " Decorative Plaster Work " at the Society of
Arts, a subject in which I felt much interest, and one on which I had previously written
and spoken. To this lecture Mr Millar came, and shortly afterwards sought me, telling
me of his craft-work, and of his proposed book on Plastering, upon which he had then
been long engaged. For this he asked for such literary help as I could give him. I
found in him a craftsman who delighted in his craft, and one who, whilst yet in his
'prentice days, finding that, unlike most other handicrafts, plastering had no text-book or
manual, set before himself the ambition of writing one. Following his father's wholesome
advice (himself a plasterer, and a descendant of a long line of plasterers), he set himself to
"learn his trade first," but whilst doing this, he kept collecting facts, and laying the
foundation of the work he has at length achieved. Fortunately he had, what is becom-
ing in these versatile days, the 7'an- advantage of a rigorous apprenticeship, and
bettered his instruction by learning more, and working through the United Kingdom,
even extending the sphere of his labour to Paris. Keeping his eyes open, he acquired
a very extended knowledge of the direct ways of his trade, and taking notes of all the
processes he came in contact with, he accumulated an extensive craft knowledge
in the byways of it. These he extended by well-directed reading, and better still by
observation, and reasoning upon what he learnt ; inventing new methods, trying new
materials, viewing both sides of the questions of the trade, now as workman and
now as master, until he thoroughly fitted himself for the task he never lost sight of, and
about 1880 commenced formulating his book. And now troubles came upon him — ill-
health, misfortune, domestic afflictions, and last of all a fire, which not only bereft him
of house and home, but burnt his treasured manuscripts and drawings, and all he had
written for his book. But Mr Millar, like a true Scot, without repining at the
inevitable, set to work again, re-wrote his manuscript and re-made his drawings.
Even yet an envious fate pursued him, for after making arrangements for their publica-
tion, and after they had been for many months in the hands of his intended publisher,
that gentleman failed, without having made any progress with the production of the
book.

vi Prefatory Note.

The present publisher havin_ij undertaken to bring his book before the world, Mr
Millar has carefully gone through the manuscript again, altering it, adding to it, and bring-
ing it quite up to date. As for me, I have simply revised it for the press, in fulfilment
of a promise I made long ago, finding, however, no alteration needed in the technical
portion. Only in the first chapter have I made anything beyond verbal alteration, and
that as small a.^ possible, leaving Mr Millar to describe in his own language the pro-
cesses he is so thoroughly familiar with. For tiie historical r<fstimd\\e had accumulated an
immense amount of matter, from which I have freely drawn, supplementing it by other
information learned from my own studies, and chronologically arranging both ; but the
value of the work is entirely due to his own labours, and I heartily congratulate him on
its final achievement after such arduous struggles. I wish it all the success his per-
severance deserves and its thoroughness should command, and I trust that such
success may encourage other craftsmen to write their own "shop knowledge" as
intelligently and as intelligibly as Mr Millar has here done that of plaster work.
To his own craft it is a life's legacy ; to the younger metnbers, it will be an
invaluable te.xt-book ; to the elder ones, a permanent pleasure. To my own pro-
fession, and to all others interested in so useful and so decorative a pursuit, it will
prove a lasting book of constant reference.

GEO. T. ROBINSON.

London, 20//; February 1897.

AUTHOR'S PREFACE.

> » <

A S kindly set forth in the " Prefatory Note," by Mr G. T. Robinson, to whom I
desire here to record my deep indebtedness and warmest thanks for much valu-
able help and encouragement, the present volume is the outcome of a long-cherished
idea pursued to its fulfilment. So far back as the time of my apprenticeship — when
attending the classes of the Edinburgh School of Arts — the need of a practical book
on Plastering and Modellino- was oreatlv felt. It was thougrht remarkable that although
many books, varying in size and in degrees of merit, dealing with other branches
of the building trades, were in use, no such book existed on this ancient and honourable
craft, and I believe that this is the first complete and practical work published on
the subject.

In preparing this work my aim and purpose has been to fill this long existing
void by furnishing for the use of my brethren of the craft a practical treatise on the
manufacture, use, and manipulation of all materials, and a description of the numerous
processes employed by plasterers and modellers.

Although fortified by a life-long study of the subject, together with a most varied
experience, I make no claim to literary ability, and would disarm my critics by
reminding them of Pope's incontrovertible poetical axiom :

" ^Vhoever thinks a faultless work to see,
Thinks what ne'er was, nor is, or e'er can be."

That this book may help to spread a knowledge of the means and methods of
executing all kinds of work in plaster, and so cause a greater appreciation of it, and
a desire tor its wider use, thus bringing about a true revival of the craft, to the benefit
both of the employer and craftsman, is my earnest wish. Should this anticipation
be realised, my reward will be in the consciousness that I have been the means of
forwarding the study of my favourite art and craft.

viii Author ^ Preface.

To the above lines (written for the most part more than four years ago), I desire to
aild. in justice to my pubUsher, that since he announced the publication of the book in
1895, I have thoroughly revised it, re-casting some parts, enlarging others, and intro-
ducing descriptions of new materials and processes. This has occupied more time than
at first seemed probable, and has caused the not inconsiderable delay that has occurred
in its production, but which, it is hoped, may be more than atoned for by the greater
completeness of the work. In conclusion, 1 have much pleasure in acknowledging the
assistance afforded me by Mr l!radk-y Batsford, especially in helping me to add
numerous valuable illustrations to those I had already drawn and collected.

WILLIAM MILLAR.
London, Manh 1897.

NOTE TO THE SECOND EDITION.

T II. WE every reason to be gratified with the success achieved by my book, as
shown by the sale of a large edition in less than two years, and the continued
demand, to meet which a Second T'ldiiion has become necessary.

1 have carefully read the book through, and have made such small corrections
anil alterations as appeared necessary. That it has defects I make no doubt, but
it is satisfactorv to know that although it has been in use in laro-e numbers duringf
nearly two years, none worthy of mention have been discovered in it either by
its u.sers, or its critics. On the other hand, I have received a laree number of
letters expressing the greatest satisfaction with it from fellow craftsmen, members
of the architectural profession, and others.

Finally, 1 may mention that the Worshipful Company of Plai-sterers were good
enough to send me not only a highly eulogistic letter, but also a handsome testimonial
of their appreciation of my work.

W. M.

.'ifanh 1899.

CONTENTS.

>*<

CHAP. PAGE

LIST OF PLATES --------- xi

LIST OF ILLUSTRATIONS IN THE TEXT - - - ' - - xiii

INTRODUCTORY— "A GLIMPSE OF ITS HISTORY" fBv G. T. Robinson,

F.S.A.) ---------- I

I. HISTORICAL PLASTERING IN ENGLAND, SCOTLAND, AND IRELAND 24

II. MATERIALS ------...- 35

III. MATERIALS— Continued -..--.- 55

IV. LIME PLASTERING _-...--.- 89
V. DECORATIVE CEILINGS - - - - - - - 123

VI. RUNNING DIMINISHED AND CIRCULAR MOULDINGS - - - 148

VII. EXTERIOR PLASTERING - - - - - - - 181

VIII. MODELLING --.----.- 224

IX. MOULDING AND CASTING - - - - - - - 249

X. MODEL AND RUNNING MOULD MAKING - - - - - 290

XI. GELATINE MOULDING - - - - - - - - 317

XII. FIBROUS PLASTER WORK - - - - - - - 343

XIII. REVERSE MOULDING -------- 380

XIV. COMPOSITIONS --------- 393

XV. SCAGLIOLA - - - - - ' - - - - 407

XVI. FOREIGN PLASTER WORK - - - - - - - 420

XVII. TERRA COTTA --------- 450

XVIII. CONCRETE - . - 456

XIX. CONCRETE— Continued - - - - - - - - 485

XX. RUDIMENTARY GEOMETRY AND ARCHITECTURE - - - 517

XXI. TOOLS AND APPLIANCES - 537

APPENDIX - - - - - 555

INDEX ---------- 580

LIST OF PLATES.

>*<

PLATE

Frontispiece.
I. Plaster Pavement at Tel-el- Amarna, Egypt, 1400 b.c. following page 34

II. Stucco Ceiling in a Tomb, Via L.vtina, Rome, Fir.st Century „ „ 34

III. Stucco Ceiling and Wall Decoration, Palazzo d'Albrizza,

Venice, BY A. Vittorio, 1560 - - - - - „ „ 34

IV. Stucco Ceiling, Over-door, and Wall Decoration, Palazzo

d'Albrizza, by A. Vittorio, 1560 - - - - „ „ 34

V. Stucco Pillars, Courtyard of the P.\lazzo Vecciiio, Flor-

ence, 1566 - - - - - - - ., .. 34

VI. External Plaster Work, Ancient House in Clare, Suffolk,

1473 - - - - - - - - .... 34

VII. Plaster Ceiling, LosELY House, NEAR Guildford, 1562 - „ „ 34

VIII. Plaster Ceiling, Cooper's House, Great Yarmouth, 1596 - „ „ 34
IX. Plaster Ceiling, Peartrees House, Great Yarmouth, Six-
teenth Century - - - - - - .... 34

X. Plaster Ceiling, 4 South Quay, Great Yarmouth, Sixteenth

Century - - - - - - --.... 34

XI. Plaster Ceiling, Bramshill, Hampshire, 1603 - - - „ .. 34

XII. Plaster Ceiling, Audley End, 1610 - - - - „ „ 34

XIII. Plaster Ceiling, State Bedchamber, Boston House, 1623 - „ „ 34

XIV. Plaster Ceiling, Craigievar, Aberdeenspiire, 161 1 - - . ,. 34
XV. Plaster Ceiling, Moray House, Edinburgh, 161 8 - - ,. ., 34

XVI. Plaster Ceiling, Winton House, Midlothian, 1620 - - ,. „ 34

XVn. Stucco Ceiling, Holyrood Palace, Edinburgh, 1671 - - ,. ., 34

XVIII. External Plaster Work, Sparrow House, Ipswich, 1683 - „ „ 34

XIX. Plaster Ceiling, Church of St Martin's -in -the- Fields,

London, 1722 - - - - - - - .... 34

XX. Pl.aster Ceiling, Queen's Bedchamber, Palace of Versailles,

Louis XV. - - - - - - - .... 34

XXI. Plaster Ceiling, Salon des Medailles, Palace of Ver-
sailles, Louis XV. - - - - - - .... 34

XXII. Plaster Ceiling, Study of the Queen of Italy's Villa,

Turin, Eighteenth Century - - - - - ■, ., 34

XXIII. Plaster Ceiling, Milton House, Canongate, Edinburgh,

1725 - - - - - - - - .... 34

XXIV. Plaster Ceiling and Cornice, Dining-room, Coleshill, Berk-

shire, by Inigo Jones, 1750 - - - - - .... 34

XII

PLATE

XXV.

XW'I.

XXVII.

XXVIIi.
XXIX.

XXX.

XXXI.
XXXII.

XXXIII.
XXX I \'.

XXXV.

XXXVI.

XXXVII.

XXXVIII.
XXXIX.

XL.

XLI.

XLII.

XLIII.

XLIV.

XLV,

XLVI.
XLVII.

XLVI 1 1.

XLIX.

LI.

LII.

List of Plates.
I'L.vsTKK Ceiling, Queen's Room, Oij> Bl'CKIxgii.xm House,

London, dv R. An.\M, 1760

folloiving page 34

ri..\sTKR Ceii.inc, Kedleston, Dekbv.siiike, hv G. RlCII.\Kr)SON,
1770 .-------

Plaster Ceiling, Lord Montalts Mansion, Dublin, hv G.
r1ciiakd.s0n, 1770 ......

Wall Decor.vtion, bv Pergolesi, 1768 -

Elevation oe Corinthian Entablature and Plan oe Cornice
AT External Angle ------

Perspective View oe Plaster Ceiling in King Charles'
Room, W'inton House, Midlothian, 1620, with Working
Plan --------

Pla.ster Ceiling, Princes Street, Edinburgh, 1850 -

Pl.\ster Ceiling, Throne Room, Holvrood Palace, Edin-
burgh, 1854 -------

Pl.\ster Ceiling at Bradford in the Ada.m Style, 1879

Pl.\ster Ceiling and Wall Decor.\tion, Hill Park House,
FoREAR, Scotland, 1870 . - - - -

Decorative Plaster Work in Staircase over Entrance
Hall, Park Circus, Gl.vsgow, 1880 - - - -

Plan of Drawing-room Ceiling at Toddington, Gloucester-
shire, 1819 -------

Perspective View of Drawing-room at Toddington, Glou-
cestershire, 1819 ------

Groined Ceiling, Trinitv College, Perthshire, 1845

Setting out and Plastering Cupola Panels and Mould-
ings, AND Soffits of Arches - - -

Circular Mouldings on Circular Surfaces -

Italian Renalssance Panels from Venice

Moulding Busts in Gelatine - - . - -

Ceiling in the Saloon at Coombe Park, Sevenoaks, De-
signed AND Modelled bv Walter Crane -

Pla.ster Work of Mihrab in Abul Hacen's Mosque,
Algiers, 1296 -------

Plaster Ceiling, Persia, Eighteenth Century

Moorish Plaster Work, Entrance to the Court of the
Lions in the Alhambra, Spain, Thirteenth Century -

Diapered Pl.\ster Panelling in the Alhambra, Spain,
Thirteenth Century ------

Plaster Decoration in a Synagogue, now Church called
Del Transito, in Toledo, 1366 - - - .

Plaster Ceiling in a Tomb at Delhi, 1528 -

Plaster Centre Flower from Berlin, by R. Schirmer

Plasterers' Tools, Plant, and Appliances

., 34
,, 34

facing page 1 12

134
■36

138
138

140

142

164

172

174
236
326

402

424
426

428

430

432
434
444

538

LIST OF ILLUSTRATIONS IN THE TEXT.

->-♦-<-

NO.
I.

S-

10.

1 1.

12.

13-
14-
15-
1 6.

17-
i8.

19-

20.
21.

22.

23-
24.

25.
26.

27.
28.

29.

30.

Stucco decorations on a vaulted ceil-
Great Baths,

ing, Rome

Stucco decorations

Pompeii - - - -

Stucco ceiling, Ducal Palace, b\- A.

Vittorio - - - -

Stucco ceiling, Scala di Giove, P'lorence
Stucco decoration, Palace of Fontaine-

bleau - - - -

External plaster work, Wyvenhoe
Plaster ceiling, London, 1620
Plaster ceiling. Lime Street, London,

1620 - - - -

Plaster ceiling, London, 162S
Plaster ceiling, Carnock Castle
Elevation and profile of cornice,

Milton House . - .

Cement testing machine
Wall plumbing _ . -

Skirting formation - - -

Modillion - - _ -

Corinthian cornice - - -

Mitre mould - - - -

Frieze, Palace Chambers, London
Fret ornaments
Plaster ceiling, Careath House
Plaster ceiling, Beeslack
Fibrous plaster ceiling, Liverpool
Plaster ceiling, Dublin
Jack template, and spike and rope

bracket - - - -

Plan of intersection board
Elevation of ribs, plan of wall inter-
section board, and pin-mould
Half-rib pin-mould - - -

Panels for panelled ceilings, classic

style ... -

Diminishing colunms, trammel and

floating rule - . .

Diminished fluted columns -

PAGE NO. P.\GE

31. Floating fluted columns, rim method 156

5 32. Forming fluted columns, collar method 157

33. Section of cove, showing pressed

6 screed process - - - 158

34. Floated coves, levelling rule - - J 59

10 35. Section, double diminished mould-

11 ings, false screed method - - 160
36. Elevation of double diminished

13 mouldings - - - 160

17 37. Elevations and section of running

18 mould for double diminished
mouldings, diminished rule method 162

19 38. Elevations, plan, and sections of ditto,

20 top rule method - - - 163

21 39. Trammels - - - - 167
40. Template and pin-mould for running

22 elliptical arch mouldings - - 169
59 41. Setting out and constructing plasterer's

93 oval - - - - 170

lOi I 42. Plans and elevations of coved ceilings 172

113 j 43. Forming niches with running moulds 179

1 14 I 44. Plumbing running moulds - - 186
116 ! 45. Pitch of pediments - - - 192

118 I 46. Raking mouldings - - - 193

119 i 47. Side and front elevation of Ionic

135 modillion, with raking modillion - 194

136 , 48. Setting out and forming a Doric

138 portico - - - . IQ5

139 49. Setting out triglyphs - - 196
50. Setting out and forming Ionic niche - 197

144 51. Plain pedestal . - - igg

145 52. Setting out and forming compound

open pediment - - - 199

146 ' 53. Front and side elevation of modillion

146 for exterior work - - - 199

54. Setting out and forming block cornice

147 and quoins . - . 200

55. Setting out quoins - - - 201
149 56. Plan and elevation of gateway, with

152 rustications . . - 202

XIV

List of lUitstmtioiis in flic Text.

NO.

57-

58.
59-

6o.

6i.
62.

63-
64.
65.
66.
67.

68.
69.
70.
/'•

/ 0-

74-

75-

76.
77-
78.

79-
So.
81.
82.

83-
84.
85.
86.
87.
88.
89.

90.

91.
92.

93-
94-
95-

Columns and arches, the Corinthian

order over the Ionic on a rustic

basement - - - -

15alustrade construction

I'iain and enriched baUisters, round,

square, and octa5.j()nal on plan
Examples uf pierced work for balus-
trades . - - -
Korminj; windows
Forminj^ window heads
Forming dormer window
Settinij out an Klizabethan sjjable
Sgraffitto frieze from I'lorence
Sgraffitto frieze from Rome -
Sgraffitto panels, by G. T. Robin-
son, I'.S.A.
Sgraffitto panels, do. do. -
Sgraffitto retable, do. do. -
Sgraffitto frie/cs in two colours
Sgraffitto frieze in two colours
Sgraffitto frieze in three colours and
shading tints . - -
Sgraffitto border in two colours
Sgraffitto border in two colours
Plaster ceiling, centre ])anel fresco,
modern - - - , -
Anatomical figure
\'enus of Milo
Exterior ornamentation in Portland

cement, mf)delled in situ -
Frieze, modelled in situ
Modelling stool

Hust support - - - -

Wood modelling tools
Wire modelling tools
Adjustable calipers -
Pilaster panel from Venice -
Truss . . - .

Ornamental pilaster -
Patent |jlaster-box - - -

Making a front wax mould and an

open front wax mould

Making jointed and surface wax

moulds - . . .

Making a front and back wa.x mould

Making a moulding piece from a

front and back mould
Plaster piece moulding a modillion -
Plaster piece moulding a baluster
Plaster piece moulding a vase

PAGE

NO.

96.

203

97-

205

98.

99.

206

100.

101.

207

102.

208

209

103.

210

21 I

104.

212 '

105.

213

106.

214

107.

214

215

108.

217

109.

218

1 10.

219

1 1 1.

220

221

1 12.

222

225

113-

226

114.

231

•IS-

232

116.

233

117.

233

118.

234

119.

235

120.

235

121.

237

122.

238

123.

238

124.

250

125.

126.

254

127.

257

128.

259

129.

260

269

130.

272

131

275

132

Reducing or enlarging irregular

figures . - . -

Setting out a truss and a cornice
Making the model of a truss
Keystone - - - -

Hinged moulds

Corinthian cajjital from Palladio
Setting out Corinthian column and

pilaster capitals
Section of mould for Corinthian

column capital
Natural acanthus leaf
Composite capital - - -

Plan and elevation of the Composite

capital - - - -

Plans, elevations, and sections of

Ionic capitals and entablature
Setting out the Ionic volute
Centre flower. Palace Club, London
Half-section of centre flower, Palace

Club, London
Plan of run body ami rim moulding

of centre flower, Palace Club,

London - - - -

Permanent joint of the body of

centre flower . . -

Centre and drop, with ornament,

roughed out in the cla_\-
Prize centre flower, plan and section
Soffit enrichment - - -

Internal mitre of soffit enrichment -
Cast enrichment mitres
To make a running mould -
Section of cornice - - -

Elevation of prize cornice
Twin-slippered mould
Radius mould _ . .

Arch radius mould - - -

Hanging running moulds
Running mould for splayed angles -
Moulding a truss with gelatine
Compound moulding piece for gela-
tine - - - .
Section and elevation of a fibrous

plaster balcony front
Running concavo-convex mouldings,

do. - - - .

Section of moulding piece, do.
Section of jelly mould, do. -
Section of cast, do. - - -

289
291
292
294
295
296

297

298
298
299

299

300
300
303

304

305
306

306

307
308
308

309
310
312
312
313
313
314
314
315
326

333

335
336
338
338

List of Illustrations in tJie Text.

133. Fibrous plaster panel for proscenium

1 34. Section of moulding piece, do.

135. Panel mould for a fibrous plaster cast

136. Casting a fibrous plaster centre

flower - - - -

137. Casting fibrous plaster plain cornices

138. Casting fibrous plaster enriched

cornices, by the bedded enrichment
system - - - -

139. Casting fibrous plaster enriched

cornices, by the cast system

140. Bench slab mould - - -

141. Finished face slab mould

142. Fibrous plaster panel with diagonal

laths - - - -

143. Setting out a reverse running mould

for a cornice . _ -

144. Reverse running mould for a cornice

casting mould

145. Reverse casting mould

146. Reverse moulds for panel mouldings

147. Reverse moulds for rib mouldings -

148. Reverse moulds for plain caps

149. Reverse casting moulds for dimin-

ished fluted columns and pilasters

150. Reverse running mould for reverse

casting mould for plain columns -

151. Reverse casting mould for plain

columns - - - -

152. Reverse moulds for over-doors

153. Panel for over-door

154. Candelabra in carton-pierre -

155. Plaster ceiling, with figure panels in

gesso - - - -

156. Ornamental plaster work on the

arcades in the Mosque of Ibn-
Tulun, ninth century

157. Plaster frieze in Mosque of Sultan

Hasan, fourteenth century

158. Plaster frieze in the Mosque of En

Nasireeyeh

159. Ceiling, Kalanoun Mosque, in Cairo,

fourteenth century

160. Cornice, Kalanoun Mosque, in Cairo

161. Arabesque from the Great Mosque,

Damascus

162. Arabian panel - - -

163. Plaster and glass window from Cairo

164. Plaster frieze from Turkey -

165. Persian ceiling from Teheran

PAGE

341
342
348

351

354

357

362
369

375

377

381

382
384

384
385
385

386
38S

389
390
391
395

403 193

421
422
422

423
423

424
425
425
42s
426

166. Persian centre-piece

167. Persian plaster panel

168. Persian plaster frieze

169. Persian plaster chimney-piece and

wall decoration - - -

170. Persian plaster frieze

171. Setting out plaster prisms for penden-

tive ceilings (Moorish)

172. Indian centre-piece - - -

173. Indian centre-piece -

174. Coved ceilings of circular rooms

175. Enriched soffits of arches from Rome

176. Stucco frieze from the Ducal Palace,

Venice - - - -

177. Cartouche from the Bibliotheque

Nationale, Paris -

178. Cartouche, Lyons - - -

179. Plaster ceiling (German)

180. Plaster cornices (German) -

181. Plaster wall panel (German^

182. Plaster ceiling, Vienna

183. Plaster angle piece, Vienna -

184. Portion of an external column, Vienna

185. Pilaster panel, Brussels

186. Pilaster panel, Brussels

187. Keystones and antefix

188. Sections of concrete kerb, channel,

and paving

189. Examples of grooved surfaces

190. Half plan of coach yard

191. Plan of stable floor -
Sections of the various parts of stable

floor - - - -

Sections of nosing moulds with riser
boards - - - -

194. Jointed nosing mould with riser board

195. Framing for concrete stairs con-

structed in situ - - -

196. Sections of framing of soffit of stairs

197. Sections of steps - - -

198. Treads and risers - - -

199. Closed outer strings

200. Wedge casting mould

201. Moulds for casting blocks and string

mouldings - - -

Moulds for casting sills and copings
Moulds for casting concrete mould-

192

202.
203.

mgs tn sttn

304.

Setting out ovals, arches, octagons,
and templates - - -

PAGE
427

427
428

429
430

430

434
434
437
438

439

439
440
442
443
444
445
446

447
448
44S
452

473
475
477
478

478

488
488

489
492
496
496
496
505

506
506

508

518

XVI

List of Illnstratious in the Text.

205. Setting' out arches - - - 5 '9

206. Setting out Gothic arches, panels,

and angles - - - 520

207. Setting out angle brackets for coves 522

208. Setting out angle brackets for cor-

nices . . - . 522

209. Mouldings, plain and enriched - 523

210. Setting out Roman mouldings - 525

211. Setting out Grecian mouldings - 526

212. Setting out a bead and scotia - 526

213. Columns and entablatures - - 527

214. Columns and entablatures - - 527

215. Acanthus mollis, The - - 528

216. Grecian capital . - - 535

217. Tuscan column and entablature - 530

218. Setting out an Ionic pedestal for a

column - . - - 530

219. Corinthian capital - - - 531

NO.

220.

22 1 .
222.
223.

Columns and entablatures in the

Corinthian and Composite orders
Doric impost and archivolt mouldings
Ionic impost and archivolt mouldings
Tuscan impost and archi\olt mould-

224. Corinthian impost and archivolt

mouldings

225. Composite impost and archivolt

mouldings

226. Biilusters of the five orders and

ramjjed balustrade

227. Setting out balusters and pedestals

for balustrades

228. Mitring and stopping tools -

229. Scratch tools . . .

230. Plaster small tools - - -

231. Plasterers' plant and labourers' tools

532
533
533

533

534

535
543
544

545
547

PLASTERING-PLAIN AND DECORATIVE.

INTRODUCTORY CHAPTER.
^ GLIMPSE OF ITS HISTORY.

By G. T. ROBINSON, F..S.A.

Plastering— Prehistoric— In the Dawn of History— In Early Egypt— Amongst the Greeks and
THEIR Colonies— Roman Work from the Commencement to the Decline and Fall of the
Empire— Its Oriental Development— In the Middle Ages— In the Renaissance— Its Culmi-
nation, in the Sixteenth Century— Its Decorative Growth in France and England— Under
Francis I. AND Henry VIII.— Under the Stuart Dynasty- Its Decline under the Hanoveri.\n
Influence— Its low Condition at the end of last Century— Its hoped for Revival.

Pla.STERIXG is one of the earliest instances of man's power of inductive reasoning, for when men
built they plastered : at first, like the birds and the beavers, with mud, but they soon found out a
more lasting and more comfortable method, and the earliest efforts of civilisation were directed to
plastering. The inquiry into it takes us back to the dawn of social life, until its origin becomes
mythic and prehistoric. Into that dim, obscure period we cannot penetrate far enough to see
clearly, but the most distant glimpses we can obtain into it show us that man had very early attained
almost to perfection in compounding material for plastering. In fact, so far as we yet know,
some of the earliest plastering which has remained to us excels, in its scientific composition,
that which we use at the present day, telling of ages of experimental attempts. The pyramids of
Egypt contain plaster work executed at least four thousand years ago (some antiquaries, indeed,
say a much longer period), and this, where wilful violence has not disturbed it, still exists in per-
fection ! outvying in durability the very rock it covers, where this is not protected by its shield of
plaster. Dr Flinders Petrie, in his " Pyramids and Temples of Gizeh," shows us how serviceable and
intelligent a co-operator with the painter, the sculptor, and the architect, was the plasterer of those
early days, and that to his care and skill we owe almost all we know of the history of these distant
times and their art. Indeed the plasterer's very tools do yet remain to us, showing that the technical
processes then were the same we now use, for there are in Dr Petrie's collection at University
College, London, hand floats which in design, shape, and purpose, are precisely those which we
use to-day. Even our newest invention of canvas plaster was well known then, and by it were
made the masks which yet preserve on the mummy cases the lineaments of their occupants.

The plaster used by the Egyptians for their finest work was derived from burnt gypsum, and
was therefore exactly the same as our "plaster of Paris." Its base was of lime stucco, which, when
used on partitions, was laid on reeds, laced toget'ner with cords, for lathing, and Mr Millar, who
has examined a fragment in Dr Petrie's collection, finds it practically " tliree coat work," about
J of an inch thick, haired, and finished just as we do now.

Plaster moulds and cast slabs exist, but there does not appear any evidence of piece moulding,
nor does any evidence of the use of modelled work in plaster exist. That some process of iiidurat-

2 Plastering — Plain and Decorative.

iiig plaster was tluis carl)- known is evidenced by the plaster pavement at Tel-el-Amarna, wliicli is
elaborately painted. The illustration of it given on Plate I* is taken from a drawing b\- Dr
Fetrie. and kindly lent b>- the editor of The Builder. This floor is laid on brick ; the first coat
is of rough lime stucco about i inch thick, and the finishing coat of well-haired plaster about \
inch thick, very smooth and fine, and showing evidence of trowelling, the setting out lines for the
painting being formed by a struck cord before the surface was set, and tlie painting done on fresco.
It is about 60 by 20, and formed the floor of the j^rincipal room of the harem of King Amenhoted
I\'., about fourteen hundred j-ears before Christ, that is, between three thousand and four thousand
years ago. Long before this, plastering of fine quality e.Kisted in Egypt, and so long as its civilisa-
tion continued it aided the comfort of the dwellings of its people and the beauty of its temples.

Nor was it merely for its beauty and comfort that plaster work was used. Even then its
sanitary value was recogni.sed, and the directions gi\en in Le\-iticus xiv. 42-48, which was pro-
bablj- written about one hundred j-ears before this date, show that the knowledge of its antiseptic
qualities was widelj- spread, and the practice of it regarded as religious duty.

Unfortunately there is no direct evidence that the adjacent Assyrian powers of Nineveh and
Babylon used plaster work. PossibK- the fine clay brought down hy the rivers of the Euphrates
and the Tigris .sufficed for all their jjurposes. Their records are in it: their illustrations on tlic
sculptured walls of their palaces are in stone, their painting is glazed on their bricks, and for them
there .seems to have been but little need for plaster work, nor do we find until the rise of Grecian
art anj-thing relating to our subject.

Very earlj- in Greek architecture we find the u.se of ])laster, and in this case a true lime stucco
of most exquisite composition, thin, fine, and white. Some has been found at M)xena;, a city of
Homeric date. \\'e know that it existed in perfection in Greece about five hundred years before
the Christian era. With this the temj^les were covered externall)-, and internally where they were
not built of marble, and in .some cases where they were. This fine stucco was often used as a ground
on which to paint their decorati\e ornament, but not unfrequently left quite plain in its larger masses.
and some of it remains in very fair preservation even to this clay. The Temple of Apollo at Bassa;,
built of yellow sandstone about 470 B.C., has on its columns the remains of a fine white stucco.

Pavements of thick hard plaster, stained, of \arious colours, were common in the Greek temples.
One of these, that of the Tem])le of Jupiter Panhellenius at /Egina, built about 570 Ji.c, is
described bj- Cockerell as existing in the early part of this century, in good condition, though the
temple itself was destroyed ; and I have seen at Agrigentum, plaster existing in perfect state,
though scarcely thicker than an egg-shell, on the sheltered parts of a temple built at least three
hundred years before our era, whilst the unprotected stone was weather-worn and decaj-ed.

What care the ancient Greeks bestowed on their stucco may be inferred from Pliny's state-
ment that in the temple at Elis about 450 B.C., Panrenus, the nephew of Phidias, used for the
groundwork of his picture " stucco mixed with milk and saffron, and polished with spittle rubbed
on by the ball of the thumb, and," saj-s he, " it still retains the odour of saffron." L)sippus, the first
of the Greek "realists" in sculpture, was the first we hear of who took casts of the faces of living
sitters about 300 B.C., so the art of plaster casting must have advanced a good deal bj- that time, as he
made presents of copies to his friends. Afterwards we read of many sculptors who sent small plaster
models of their works to friends. These were, however, probably carved in the plaster rather than cast.

W hether the Greeks used stucco for modelling is a somewhat doubtful point amongst
antiquarians. From certain passages in classic writers I am induced to think they did. Pausanius,
* Plates I. to XWIII., illustrating this and the following chapter, will be found after page 34.

Amongst the Greeks and their Colonies. 3

who describes the temple at Stymphalus, an almost deserted and ruined city when he visited it
about 130 A.D., describes the ceiling of the Temple of the Stymphalides, built about 400 B.C., as being
" either of stucco or carved wood," he could not decide which, but his very doubt would imply that
stucco or wood were equally common. Xow this ceiling was ornamented with panels and figures of
the harpies— omens of evil, half woman and half bird, with outspread wings. He also mentions a
statue of Bacchus in " coloured stucco." Of course these are not definite proofs of early Greek stucco
modelling, but as the city of Stymphalus had decayed and become depopulated before 200 B.C., there
is certainly presumptive evidence of the ancient practice of the art. Again, figures of unburnt earth
are mentioned in contradistinction to those of terra cotta, and sundry other allusions to plastic work
occur, which lead me to the opinion that quite early in Greek Art this mode of using plaster began.
At any rate, we know that it was early introduced into Grecia Magna — the earliest Southern Italian
colony of the Greeks ; and as colonists invariably preserve the customs and traditions of their
fatherland even long after they have fallen into disuse in their native home, we can have no reason-
able doubt but this art was imported rather than invented by them. Thence it spread to the
Etruscans of Middle Italy, a cognate people to the Southern Greeks, by whom both plain and
modelled stucco was largely used. The Etruscans, as we have seen, were more closely allied to
the Greek than the Latin race, but in the course of time these two races amalgamated, the former
bringing skill in handicraft, the latter lust of power, and patriotic love of country and of glory,
whilst the Grecian element, which blended harmoniously with the first of these, added a love of Art
This union, however, took long to ripen to artistic fruitfulness. The practical Etruscan element
firstly constructed the roads and the sewers, and gave health to Rome. The Latins added to their
territory until it embraced half of Europe, giving wealth to Rome, and not till the luxury and
comfort thus created did the artistic element of the Greek come in, giving beauty to Rome, and the
day of decorative plaster work approached its noontide glory, making Rome the attraction of the
world. The absorbence of Greece as a Roman province took place B.C. 145, and the loot of it began,
giving an enormous impetus to Roman Art. Thousands of statues were brought to Rome, and to
be deemed a connoisseur in things artistic or a patron of the arts became the fashionable ambition.
But it was not until the century just preceding the Christian era that it became especially note-
worthy. Of course there is hardly anything left to us of the very early plaster work of Rome.
The constant search for some new thing was inimical to the old. Old structures were pulled down
to make way for new, which in their turn gave way to newer, and until the age of Augustus we
have but little of the early work left. Strabo, who visited Rome about this time, complains of
the destruction caused by "the numerous fires, and continued pulling down of houses rendered
necessary, for even pulling down and rebuilding in order to gratify the taste is but voluntary ruin";
and Augustus, who boasted that " he found Rome of brick and left it of marble," in replacing the
brick with marble destroyed the plaster work. How that plaster work was wrought we shall learn
more from Vitruvius, who wrote his book on architecture about 16 B.C., and dedicated it to the
emperor, " in order to explain the rules and limits of Art as a standard by which to test the merits
of the buildings he had erected or might erect."

Xow, Vitruvius was a man who had travelled and seen much. He was with Julius Cxsar as a
military engineer in his African campaign in 46 B.C., or ten years after Caisar's invasion of Britain.
Afterwards he became a designer of military engines, what we should call head of the Ordnance
Department, and also a civil engineer, persuading himself that he had a pretty taste in architecture,
just as though he were an R.E. of to-day. Thus he had a practical and also an artistic
training, and here is what he says on matters connected with plaster work in Book VII.,

4 Plastering— Plain and Decorative.

C"h:ii>tcr II. On tempering; lime for stucco: "This requires that the lime should be of the
best cjuahty, niul tempered a long time before it is wanted for use ; so that if an\- of it be
not burnt enough, the lenijtli of time emploj'ed in slakin<( it may bring the whole mass to
the same consistency." He then advises it to be chopped with iron hatchets, adding that "if
the iron exhibits a glutinous substance adhering to it, it indicates the richness of the lime, and
the thorough slaking of it." I'or cradling out, and for ceiling joists, he recommends " the wood to
be of cypress, olive, heart of oak, box, and juniper," as neither liable to "rot or shrink." For lathing
he specifics, " Greek reeds bruised and tied with cords made from Spanish broom," or if these are
not procurable, " marsh reeds tied with cords." On these a coat of lime and sand is laid, and an
additional coat of sand is laid on to it. As it sets it is then polished w ith chalk or marble. This
for ceilings. For plaster on walls he says : " The first coat on the walls is to be laid on as roughly
as possible, and while drying, the sand coat spread thereon. When this work has dried, a second
and a third coat is laid on. The sounder the sand coat is, the more durable the work will be. The
coat of marble dust then follows, and this is to be so prepared that when used it does not stick
to the trowel. Whilst the stucco is drying, another thin coat is to be laid on ; this is to be well
worked and rubbed, and then still another, finer than the last. Thus with three sand coats and
the same number of marble dust coats the walls will be solid, and not liable to crack." " The
wall that is well covered with plaster and stucco, when well polished, not onl\- shines, but reflects to
the spectators the images falling on it. The plasterers of the Greeks not only make their stucco
work hard by adhering to these directions, but when the plaster is mixed, cause it to be beaten
with wooden staves by a great number of men, and use it after this preparation. Hence some
persons cutting slabs of plaster from ancient walls use them for tables and mirrors" (Chapter III.).

You will see by these remarks the great care taken through every process, and how guarded
the watchfulness over the selection of materials, and you will also note the retrospectiveness of
Vitruvius' observation, how he felt that the work done before the frantic haste of his own time was
the better: very much as we find nov^-. Time is an ingredient in all good work, and its substitute
difficult to find.

There are other "tips" contained in Chapter III. which are worth extraction, as, for instance,
his instructions as how to plaster damp walls. In such case he primarily suggests a cavity wall, with
ventilation to ensure a thorough draught, and then plastering it with " potsherd mortar," or carefully
covering the rough plaster with pitch, which is then to be " lime whited over," to ensure " the
second coat of pounded potsherds adhering to it," when it may be finished as already described.
F"urther, he refers to modelled plaster work, which, he says, " ought to be used with a regard to
propriety," and gives certain hints for its appropriate use. Speaking of pavements " used in the
Grecian winter rooms, which are not only economical but useful," he advises " the earth to be
excavated about 2 feet, and a foundation of potsherds well rammed in," and then a "composition
of pounded coals, lime, sand, and ashes is mixed up and spread thereover, i foot in thickness,
perfectly smooth and level. The surface then being rubbed with stone, it has the appearance of a
black surface," " and the people, though barefoot, do not suffer from cold on this sort of pavement."
Now all this bespeaks not onlj^ theoretical knowledge, but practical obser\ation and experience,
and was written nearly two thousand years ago, from which you can surmise how far advanced
practical plastering had then become. This written evidence is almost all we have of the work of
Vitruvius' own time, for even of the time of Augustus hardly anything remains to us, as the great
fire of Nero utterly destroyed the greater part of the city in the j-ear A.D. 64, and almost the
only authenticated piece of plaster work done before or during his reign is the Tabula Iliaca, a

Early Roman Work. 5

bas-relief of the siege of Troy, still preserved in the Capitol Ivluseum at Rome. That this was
modelled by Greek artists is proved by the fact that its inscriptions are all in Greek language, and
by some it is considered to be of very much greater antiquit)-.

Illustration No. i shows a good example of the character of modelled stucco which prevailed
about this period. This is a small portion of a large surface of plaster which was on a vault cut
through in making the excavations for the canalization of the Tiber at Rome. There were many
compartments of various sizes, and the modelling is of an exquisite delicac}\ Casts of these you
can see in South Kensington Museum, and some of the smaller cartouches are almost as fine as
cameos. In the same valuable museum you will find a series of arched tiles of very bright red, on
which small subjects have been modelled in stucco, forming a very pleasing and suggestive combina-
tion. These are from an Italo-Greek tomb, and of the early part of first century. Of about the
.same date is the example given on Plate II., from the vaulted ceiling of a tomb in the Via Latina

No. i.— Stucco Decorations on a Vaulted Ceiling, Rome, Kikst Century.

at Rome, the walls of which are covered with some very delicatelj- modelled arabesque ornament.
Both these are evident!}' the work of Greek artists. The more Roman method is shown in
Illustration No. 2, from the Great Baths of Pompeii, which must have been executed before the
year 79 A.D., when the citj' was buried by the ashes thrown up in an eruption of Vesuvius, and with
it perished the natural philosopher and historian, Pliny the younger, who tells us that "no builder
should employ lime which had not been slacked at least three years," " and that the Greeks used
to grind their lime very fine," and that they beat it with pestles of wood. The verj- eruption which
destroyed Pompeii preserved it to us, for the light scoria which fell upon it covered up the most
delicate work, and it is now a museum of decorative plaster work and decorative art generallj-, for
there stucco treatments abound. Not only did it decorate, but it preserved the fragile and inflam-
mable structures by its fireproof coating. The ordinary plaster was evidently prepared according
to the prescription of Vitruvius, the sand coating, or arenatum, he describes being here formed
of decomposed lava or volcanic sand, the final coat laid on being very thin, less than yV inch in the

6 Plastcriiig — Plain and Decorative.

best work. When colour was used it was chiefly fresco, done whilst the plaster was moist. Some-
times the colour was even mixed with the plaster, and every variety of plastering skill was called
into ser\ice, scagliola, gesso, sgraffitto, impressed and relieved work, for J'ompcii was evidently a
city of plaster work, but I am afraid the "jerry" builder was born before much of Pompeii was
built, and then, as now, he relied upon the plasterer to cover up his iniquities.

There was more solid construction at Herculaneum, which was destroyed by the .same volcanic
eruption, but there, unfortunately, lava, hot and semi-fluid, was the overwhelming substance, and
thus the more delicate fabrics perished. Of course much of the work thus destroyed was of earlier
a date than that of the catastrophe, though unfortunately we have no record of its technical
history ; as far, however, as classic times are concerned, plaster work became an artistic aid, reflecting

No. 2. — Stucco UEcoRATiONSi Great Bat)is, I'o.mpeii, First Century.

the general tendency of the times. Luxury begot lasciviousness and obscenity, and the moral,
physical, and political decay of the Roman Empire led to its d(jwnfall, while the Puritanism begotten
of the persecution of the Christians led to an iconoclastic destruction of every artistic thing, sacred
and profane, and so ended artistic plastering in Rome. During Constantine's reign it passed away,
and on his transfer of the capital of the Empire to Constantinople, what little building was then done
then resulted in that Byzantine style of stiff, formal, plastic art which, though of archaeological
value, presents nothing pertinent to the present subject. Julian " the Apostate," notwithstanding
that he married Helena, the daughter of Constantine the Great, reverted from Christianity, and
became a pagan about 380 a.d. He had amongst his household gods a statue of Apollo under the
outstretched hand of which he daily bowed his head. Now this statue was of plaster (gypsum),

Early Italian Renaissance. 7

but it was most probably sculptured in this material, rather than cast, as we find no traces of any
replica, nor does any word equi\alent to piece moulding occur in the language of this time. Hence-
forward very little was done throughout the Empire until a new Rome was founded, and for more
than a thousand years all relics of ornamental plaster work were buried and wellnigh forgotten.
Materially, as a craft, it was debased ; the old care in preparation had disappeared, and the drudgery
of careless service replaced intelligent assistance to architecture and sculpture. As an art it was
dead, buried under the ruins of the buildings it had adorned, so far as Rome, the whilom capital of
the world, was concerned, and there we must leave it until we come to consider its resurrection.

There is, however, little doubt but that this Eastern removal of the Empire spread the art into
the far East, and it is probable that the over-enriched plaster work of India, Persia, and other parts
of the Indian Empires which are in question (a question we cannot yet enter fully into, owing to the
very little knowledge we possess of their archaeology), is largely due to the dissipation thus effected.
The Arabian and Moorish results of this were brought back to the Western world by the Moors in
the early part of the thirteenth century, to whom we owe the splendid plaster work of the
Alhambra described in Chapter X\T.

During the Middle Ages plastering existed only as a craft, and its highest function was to
prepare a surface to be painted on. Sometimes it was used as an external protection from the
weather, but rarely was it emplo}-ed for direct adornment. Sometimes small ornaments were
car\ed in plaster of Paris, but it pla}-ed no important part in decorative art, excepting, perhaps, as
gesso, though this belonged rather to the painter than the plasterer; nor was it until the commence-
ment of the Renaissance in Italy that it showed an\- s\-mptoms of revival.

After the long night of darkness which thus overshadowed learning and the arts, the dawn of a
new era, to which wc ha\-e gi\"en the name of the Renaissance, began. With the commencement of
the fifteenth century old learning and old arts began to be studied, literature leading the way, as it
always does, and their study was enormously facilitated by the discovery of the art of printing,
and the consequent multiplication of the copies of the lore heretofore locked up in old manuscripts.
We can glean somewhat of what was the state of the plaster-worker's art at that time b\- glancing
at some of the old recipes which have been handed down to us in the notebooks of the artists of
that dawning time. Amongst the foremost of them was Cennini-Cennino, a painter born about
1360, a pupil for twelve years of Agnoto Gaddi, of Florence (who died in 1378J ; towards the end of
his long life Cennino wrote a book compiled from his notes of all recipes and directions for the
conduct of all artistic proces.ses known to him, and this book he finished on 31st July 1437 —
unfortunately dating it from " the debtors' prison at Florence." He also gives us directions " how to
take casts from the face of man or woman," which is much the same as our modern process, and was
doubtless that of L\-sippus ; but he quaintly remarks that " when }-ou take the cast of a person of
high rank, such as a lord, a king, a pope, or an emperor, )-ou should stir rose water into the plaster,
but for other persons it is sufficient to use cold water from fountains, ri\ers, or wells." In taking a
cast from this mould, he advises the addition of a little pounded brick. In this there is as yet no
reference to piece moulding, and it is very doubtful if these processes were then known. The
nearest approach to such a suggestion is contained in the instructions " how to take a cast of the
whole figure of a man." " In such case you must let the person stand upright in a box, joined
together lengthwise, which will reach as high as the chin. Let a thin copper plate be placed against
the shoulders, beginning at the ear and reaching to the bottom of the case, and bind it with a cord
to the naked person, so as not to injure or press into, the flesh. Cut four copper plates like this,
and join them together like the edges of the case. Then grease the naked person, put him directly

s Plastcri)ig — Plain and Decorative.

into the case, mix a large quantity of plaster with cold water, and take care to have an assistant
with you ; and while you pour plaster into the case in the front of the man, let the assistant fill the
back part at the same time, so that it may be filled to the throat. Let the jjlaster rest until it be
quite set and dry, then open the case, separate the edges of the case from the cojjper bands with
chisels, and open it as you would a nut. Withdraw the naked person very gently, wash him quickly
with clean water, for his flesh will be red as a rose. With regard to the face, >-ou may do that
another time " ! I do not expect a chance to cast from a living face would occur after such a process.

This ma}-, I think, be taken as a merely theoretic instruction, showing more desire than facility,
but is sufficient to show that piece moulding was not known to Ccnnino, if indeed practised by any
one at his time. In another recipe he gravely bids any one wanting to take a cast of himself to
spread a bed of wax about 9 inches deeji on the dining-table and tlien lie down upon it, taking care
not to disturb the mould when he gets up. From this mould he takes a plaster cast, and then
carefully lies down on his other side and completes the mould ! ! Comment is unnecessary, and it is
onl\- from their negative value that these casting recipes of Cennino are worth remark, .showing that
the desire for such a process was greater than its achievement. The real utility of his recipes, in a
positive direction, are those in which he treats of gesso and other painter's u.sage of the plasterer's
material. Of lime stucco he .says nothing, and all his remarks relate to plaster obtained from
g)-psum found at Bologna, or Volterra, whence comes that fine white translucent alabaster of which
small figures, vases, and models of buildings are made to this day. A more practical recipe, and
one relating to stucco, is found in the Marciana MS., which is preserved in the Library of S. Mark,
at Venice, and was written about 1503.

This is headed as "tried by Master Jacopo dc Monte S. Savino, the Sculptor." "Admirable
stucco for making and modelling figures and for colouring them, and it resists water. Take of
finely-pounded travertine 5 lbs., and if you would have it finer and more delicate, take fine
marble instead of travertine, and 2 lbs. of slaked lime, and stir and beat them well together like a
fine paste, and execute what works )ou will with it, either by forming it with your hands, or in
moulds, and dry it in the shade. And if you wish to colour it white, when the work is dry enough
to be tolerably firm, but not quite dr\-, grind white lead with water in the same way as colours are
ground, and the flour of sifted lime, and apply it w ith a brush, and it will be very white and will
effectuall)- resist water. And if you wish to colour it with other colours, let the work dry perfectly
and then colour it ; but these colours will not resist water like the white. If, then, }'ou wish the
colours to resist water, applj- on the work the above-mentioned composition and paint with oil
colours."

This brings down the literary notice of our subject to the period of Raphael and the great
revival of stucco work, before considering which we must first cast a backward glance at some
evidences of pre-Raphaelite use of it. We have actual evidence of its use by Donatello, who
practised it, and it is on record that he used pounded brick and glue with his stucco, and from this
many of his stucchi pass as terra cottas. No doubt his object was to avoid the risk and distortion
b\- baking his clay model. There is a group of the " Entombment " over the sacristy door in the
Church of S. Antonicj at Padua, which was formerly considered to be in terra cotta, but is now
proved to be of this brick-dust stucco. There are medallions of the Four Evangelists in true stucco
in the sacristy of San Lorenzo at Florence. In South Kensington Museum there is a large stucco
plaque with a low relief of the Virgin and Child, and many others are known. Now Donatello died
in 1466, proving that in the first half of the fifteenth century stucco was making progress. In South
Kensington Museum there is a very fine relief of the Virgin and Child surrounded by angels,

Italian Renaissance. 9

exhibiting very marked Gothic features in its accessories. This has the date 1430 attributed to it.
There, too, you will find many busts of very excellent modelling and great technical skill, all done
with the grey stucco. Indeed, there is plent\- of evidence that with the ad\'ance of the revival of
all the arts stucco was yearning to take its wonted place beside them. Bramante, the chief architect
of his day, was uncle to Raphael, and inspired his nephew with an enthusiastic love for architecture
and archaeological research. He, Vasari tells us, invented "a mixture of lime" with which to
decorate the exterior of his houses with festoons and friezes of foliage, and one of his last works
was the building, in 1513, of Raphael's own house, which was decorated with stucco made according
to the recipe from the Marciana MS., Jacopo Sansovino being one of the stucco modellers there
employed. Bramante died in 15 14.

Other experimenters were at work in other parts of Italy, for the endeavour to revive the lost
art of modelling in stucco was becoming general, and in Bologna Alfonso Lombardi had achieved
a pre-eminent success in the renewed art. \ot only did he model many portrait busts in stucco,,
and amongst them that of Emperor Charles V., which he did whilst the Emperor was sitting to
Titian for his portrait, but, aspiring to greater things, he executed a large group of the death
of the Virgin in a very hard stucco, which was so admired by Michael Angelo, himself a
stucco worker, that on seeing it he exclaimed, " If this stucco could only become marble, it would
be bad for the antique statues." Lombardi modelled many other statues in Bologna which were
larger than life, all executed in the gre}' lime stucco, and Cicognara styles his figure of Hercules as
the finest colossal statue of the centurj-. About the same time Andrea Verrochin really founded
the art of piece moulding in Venice, and brought the casting of plaster to such a pitch of perfection
that reproductions of ancient and modern works were easily obtainable, and thus formative art
secured an impulse the movement of which still continues.

In 1509 Raphael came to Rome, and was in 15 15 appointed by Leo X. Director and Inspector
of the search for the buried remains of Ancient Rome; and for this purpose determined, in 15 18, to
unearth the remains of the Golden House of Xero, then supposed to be the Baths of Titus, and
which for five hundred years had been buried under their own deca}'. Here was a great discover}-
and surprise. Xot onlj- were there found painted chambers, fostering the new growth of
" grotesque " ornamentation, so called from its abounding in the newly unearthed grottoes, but, more
cherished than all else, abundance of modelled stucco decorations, which had survived still better
their long entombment, astonishing Raphael and his attendant, Giovanni da Udine, b\- their hard-
ness and brilliant whiteness. This discovery was most opportune, for the decoration of the Loggia
of the Vatican was just then under consideration, and Udine set himself to work especiall}- to find
out the process and the manipulation. He sa}-s he made many experiments and re-invented the
process ; but as Raphael, who was not a Latin scholar, had just then had a special translation of
Vitruvius into Italian made for his own study, I am disposed to think this also was exhumed about
the same time. Be this as it may, the newly found stucco duro became at once the rage. With
the Vatican for a cradle, and Pope Leo X. and Raphael for its sponsors, its success was ensured ;
but unfortunatel}- those mephitic vapours engendered in the soil which so long had hidden this
brought disease with them, and there is but little doubt that Raphael's death on the 6th of April
in the following year is due to the energj- with which he sought for this buried art in the miasmatic
vaults which had preserved it. B}- his last testament Raphael left the completion of his decorative
works to Giulio Romano and Gio. Francesco Penni, who, for the stucco portion of these, allied them-
selves with Giovanni da Udine, its re-inventor, and continued the work at the Villa Madonna, then
being done for Cardinal de Medici, a cousin of Leo X., and who succeeded him as Pope in 1523.

Phntcriug— Plain ami Decorative.

You can form an idea of what the moclellcd stucco here was by examining a very beautiful
model of it which you will see in the South Kensington Museum ; but of the vastncss of the Villa
and the richness of its surroundings it would, in a short notice, be impossible to give you an
impression. Unfortunately it was partiall\- ruined before it was completed, and suffered from the
barbarities of the soldiers during the sack of Rome b>' the French in 1527. That drove Udine to
Florence, where he was much emplo>-ed by Cosimo de Medici and Michael Angelo, but in his old
age he returned to Rome, working to the last on the Loggia, on which, as a stucco worker, he began,
and where he died in 1564. He is buried in the Pantheon, close by the tomb of his loved master,
Raphael, and, as sa>-s his biographer Vasari, " we ma>' believe they are now met together in eternal
blessedness."

Giulio Romano went in 1524 to Mantua to carry out work for Duke Frederic Gonzaga, which
Raphael had, before his death, promised to undertake, and there raised up an important school of
stucco workers, who we shall see influenced the whole of Western Europe. I'ierino del Vaga,
painter and sculptor, who was one of Raphael's staff of stucco workers, having begun life as
a " hawk boy," went to Genoa, where he founded a great school under the patronage of the Doria
family, but returned to Rome when peace was restored, and worked on the Scala Regia, and man\^
of the principal rooms in the Vatican. Jacopo Sansovino, one of the first essayers of the new-
found art, went to Venice, where he fostered it, making many statues and other large works,

No. 3. — Stucco Ceili.no, Ducal Palace, by A. Vittorio, 1570.

training U|> a large school there, and in it his most celebrated pupil, Alessandro Vittorio — a man
to whom nothing was impossible. He was, in fact, too facile. But as a proof of his power you can
.see on Plates HI. and IV. .some of his work in the Palazzo d'Albrizzi in Venice, evidences of
his ingenious and daring skill. Of a less hazardous and more restrained character is his vaulted

Late Italian Renaissance.

1 1

ceiling, shown on Illustration No. 3, from the Ducal Palace at Venice, executed about 1570, but
each example of his skill is wonderfullj- \aried, and in all phases of decorative art he was an
exuberant master.

No. 4. — Stucco Ceiling, Scai..\ di Giove, Florence, ey A. Vasari, 1569.

The school which Udine had founded at Florence produced great results ; \"asari, the
biographer of so many artists, went there to work on the Pitti Palace in 1555, and of the interior
work of that school j'ou can form some idea b}- referring to Illustration Xo. 4, where \'ou will
find a portion of the ceiling from the " Scala di Giove," which \'asari commenced in 1559. There
are man}- other grand ceilings in this same palace, with marvellous stucco work designed either by
\'asari or the architect Ammanato, and executed by the school Giovanni da Udine established.
But the most interesting example of external work, as demonstrating the perfect composition of
the material and its great durabilit}', is shown in the present state of the pillars of the courtx'ard
of the Palazzo Vecchio there (see Plate V.). These were done in 1566 under Vasari's direction, and
as the names of good workmen are as worthy of record as are those of good designers, I, in praise
of their honest and perfect workmanship, give them here. The\- are — Pietro Paulo Minocci, who
afterwards settled in Parma, where he did much good work, of which some still exists ; Ricciavelli
da Volterra, who afterwards joined himself to Pierino del Vaga at Genoa and in Rome, anrl
ultimately came to England ; Sebastiano Tadda, whose relative Francesco was a noted worker
in porphyry ; and Leonardo Marignalli, of whom I ]ia\e not been able to trace anything further.
Their monument is in their work, which you will find on plaster, in Florence, and which, after five
hundred )-ears, hands down the record of their craft almost as sound as the day the\- did it. With
what they did it demands particular attention, and by a fortunate accident we have in a notebook

12 Plastci'iiig— Plain ami Decorative.

still preserved in the Bodleian Librarj- at Oxford, kept by I'irro Ligorio, a joint architect and
coadjutor with Michael Angelo for S. Peter's at Rome, and which contains the exact recipe
written just about this time. "Take," says he, "3 parts of pounded Parian marble, easily got
from among the ruins in Rome and from broken statues; add I part of lime which is to be
perfectl)- slaked b>- letting it lie in a heap covered with pozzuolana and exposed to the sun and
rain for at least a j-car. The lime is to be made from pure white marble, not from travertine,
or any other stone which is full nf holes and yellowish in tint; mix a day before with sufficient
water on a tile floor. The first coat to be mixed with coarsely pounded, and the finishing coat
with finel)' jjounded white marble." Now let us examine scientifically the rationale of all this.
Firstl)-, the lime is pure carbonate of lime ; it was naturally burnt with wood fuel, and conse-
quentlx- was free from all those sulphureous and other deleteriijus compounds inseparable from
coal firing. The air slaking of it prevented the too great absorption of carbonic acid which is
obtained by the free use of water, and which rather retards than assists the .setting of the stucco.
Then the pulverisation of the unburnt mortar introduces a fine crystalline substance into this
identical chemical composition when as yet amorphous in structure. These minute crystals
induce the formation of a general crystalline structure until the final and most permanent form of all
mineral substance is achieved. Thus the wisdom of the ancients achieved that which is only just
dawning on the modern world of science, and the as )-ct but partially understood question zvhy
lime sets, is full of thought seed for .scientific inquirj' — seed for us to propagate, and so to carry
still further the lore and practice of the plasterer, and to cultivate it into fruitful knowledge. You
will have remarked the absence of hair in any of these old formula; ; the rapidly induced crystallisa-
tion seems to have rendered this unnecessary, for the introduction of any animal substance into
plaster is an unscientific error w hich the.se old plasterers avoided.

After this digression, which these Florentine plasterers have brought about, let us return to
Mantua, where we left Giulio Romano in 1524. He there did works in painting and .stucco which
were renowned throughout Europe, and his school of stucco workers achieved such a reputation that
Francis I. wrote to Duke Frederic Gonzaga praying him to send him some j-oung man able both as
a painter and a stucco worker to assist him in decorating his new palace at Fontainebleau. This was
in 1536. After conference with Giulio Romano, the Duke .sent him Francesco Primaticcio, the .son
of a wealthy Bolognese merchant whom a love of art had seduced from the ways of commerce.
He gathered round him a large staff of modellers, of which he became superintendent, and together
the\-, according to Va.sari, " did the first stucchi ever executed in France." If the pure white stucco
is meant, this was true, but there was in France a considerable attempt to model in the ordinary
plaster before this, and many of the fine Gothic-hooded chimney-pieces in the chateaux are modelled
in plaster on wooden cradling. At the Gros Horologe at Rouen there exists some well-modelled
plaster, and there is evidence of the existence of a school of ornamental plaster workers in the valley
of the Seine some years before Primaticcio's advent. At Fontainebleau, however, he did most noble
figure work, much of it being considerably over life size ; long graceful figures, which formed the
canon for the sculptors of the French school of Gougor, Pilon, and their followers, such as you
.see in Illustration No. 5. Of course if Francis I. could thus emulate the arts of Italy in their then
most fashionable phase, his great rival, our Henry VIII., could not be outdone by him. Already
Cardinal Wolsey was busy fostering the Renaissance in England, and Henry sent, through his
ambassadors, for those who could outvie the Italians in the service of the French king. By these
means he collected many artists of renown. Amongst these were Luca and Bartholomew Penni,
brothers of that Giovanni Francesco Penni whom Raphael left fellow-executor with Giulio Romano

Decorative Gyoioth in France and England.

for the execution of his incompleted designs. Luca, who preferred painting to plastering, did
not stay long here, but deserted the king and went to join Primaticcio in France, for plasterers
who could model in stucco were the subject of much diplomatic correspondence in those days.
Bartholomew was here at any rate until 1539, as records of payment to him are recorded in that
year. Gerome of Trevisa, who, Vasari tells us, " made many ingenious devices and one honourable
house for the king's use," came, and was so much admired by King Henry VIII. that he gave him

He was killed at the siege of Boulogne in 1 544. Nicholas of

a stipend of 400 crowns a year
Modena left Primaticcio, from
whom he was receiving 20
livres a month, and came to
help us. There was also Toto
del Nunziato, whom the old
account books call Anthony
Toto, and who was a wax
modeller at Florence, whence
" sundry merchants carried
him off to England, where he
made all manner of works for
the king, and particularly the
principal palace." Now this
principal palace was that of
Nonsuch, which was so-called
because it had no equal ; it
was built at Cheam, between
Sutton and Epsom, but un-
fortunately not a vestige of
it now exists. It was a very
large and sumptuous pile, con-
taining two quadrangles, and
built in the half- timbered
st)-le, then prevalent in Eng-
land ; it was never quite
finished before the king's
death, but existed for more
than a century, sufficiently
long for record, of what these
plasterers did there, to have
been taken by those who
admired its wonders.

The Duke of Saxe-Weimar, who saw it in 1613, tells us that "the labours of Hercules were set
forth on the king's side, the queen's side exhibiting all kinds of heathen stories with naked female
figures ;" and John Evelyn, who saw it in 1665, says : " I took an exact view of the plaster statues
and has relievos inserted between the puncheons of the outside walls of the court, which must have
been the work of some celebrated Italian. I much admired how it had lasted .so well and entire
from the time of Henry VIII., exposed as they are to the air, and pit}^ it is they are not taken out

No. 5. — Stl'cco Decoration, P.^l.ace of Font.\inebleau, by Primaticcio, 1536.

14 Plastcriug— Plain and Decorative.

and placed in some dr>- place— a ^'allerj- would much become them. The\- are mcr.zo-rclkvos the
size of life." You ma>- form some idea of them bj- turning to the illustration of Primaticcio's work
at Fontainebleau. Unfortunatel\- we had not the white marble here to mi.x with the lime, so we
could not obtain the cr\-stalline qualit)- that preserved the old Italian stucco, but we learn from a
manuscript note b)^ P. le Neve that neccssit>- was the mother of invention, and that " it was done
with rj-e dough very costlj-." This would dry very slowl.\-, and give toughness to the stucco whilst
being modelled. I have tried it, and found it pleasant to work with, and it dries a beautiful
old ivor\- colour. Having thus brought the classic art of modelling in stucco into the English
Renaissance, it will be well to pause awhile and take a brief backward glance at what English
plastering was before the advent of this new fashion.

What the state of plaster working was before the Romans, under Julius Ca;sar, came, we ha\e
no knowledge. We know that the ancient Britons used houses built of hurdles plastered inside and
out with mud — the old " wattle and dab." in fact, much of which is still done in the \\'est of England.
Of course the Romans brought their arts with them, and during their four hundred }-ears' sta_\-
introduced the arts and luxuries of the capital, as the numerous ruins of their buildings show. The
Anglo-Saxons plastered many of their buildings inside and out, as the illumination in their MSS.,
and some evidences of actual work, including perhaps the plaster work on Anglo-Saxon masonr\-
at the Church of Avebury in Wilts, demonstrate. The Normans were a highlj- skilled and civilised
people, but we have no written records of hoiv the}' plastered ; that the\' did so is proved, by
existing pictures showing painted walls of great richness, which could onl)- be done on a finely
wrought field. All this was, of course, the ordinar\- lime stucco, for the use of " plaster of Paris"
or calcined gypsum was unknown in this countr)' until the time of Henr)- II., who, on a visit to
Paris in 1 254, so admired the superior whiteness and fineness of the walls, that he introduced it here.
But plaster or lime stucco was as yet in England onl\- considered as a structural ncccssit}-, and not
as a decorative adjunct ; that its fire]3ro(jf qualities and sanitary influence were known is shown b}'
the edict of King John, who, after the great fire which destroyed the timber-built London Bridge in
I2I2, issued an edict that "all shops on the Thames should be plastered and white-washed within
and without. All houses which till now are covered with reed or rush, let them be plastered w ithin
eight da\-s. and let tho.se which shall not be plastered within that time be demolished b\- the
aldermen and lawful men of the \-enue (overseers). And let all houses in which brewing or baking
is done be plastered within and without, that they may be safe from fire." A contract for plastering,
dated 13 17, exists, wherein Adam, the plasterer, a citizen of London, agrees with Sir John de
Bretagne, Earl of Richmond, to find " jjlaster of Paris" wherewith to plaster his hall well and
befittingly within and without. At Clare, in Suffolk, is a fine old house (Plate VI.), stated to be
dated 1473, a date I am somewhat sceptical about, with some very fine plaster work modelled in
relief, with figures and scroll work, but which is evidently of a later period. In 15 19, Hermann, in
his " Vulgaria," says : " Some men will have their walls plastered, some pargetted and white limed,
some rough cast, some pricked, some wrought with plaster of Paris." In fact, the plasterer's and
pargettor's art and craft had now become of such importance that it was formed into a separate
Guild and Company in London in 1501 b}- Henr)- VH., who granted them "the right to .search and
try and make and exercise due search as well, in, upon, and of all manner of stuff, touching and
concerning the art and m\-stery of pargettors, commonl)- called plaisterers, and upon all work
and workmen in the same art." • It is noteworthy that here pargettors are " commonly called

* This charter, having been frequently renewed with varying powers, still exists, but the only trade function the
Company now performs is the granting of ^25 annually to the successful candidates in the examinations conducted bv
the City and Guilds of London for Technical Examination.

Progress in England — ElizabetJian Period. 15

plaisterers," but in earlier times plasterers were commonly called pargettors. Parging was then
plastering, and I am inclined to think that when the larger surfaces of the walls admitted the use of
the "rule" and the "float" the distinction began. We still parge a chimnej'-flue, in which neither
rule nor float can be used but only the trowel. In the old timber-framed houses the want of truth
in the carpentry compelled the plaster to be laid with the trowel, hence we say they are pargetted,
not plastered, and the modelling which so frequently enriched them was done with the trowel, and
still bears the name of pargetry. We have thus seen how the taste of the time was prepared for
the introduction of the plasterers who worked in the Italian mode introduced by Henry VIII.
These kept continually coming until the death of their royal master, and having found the way
here remained for many j-ears after. Thus we have a De Rudolfi here in 1550, who was most
probably a relative of Bartholomew Rudolfi, who worked in Venice and Padua, where he married
the youngest daughter of Titziano Minio, also a stucco worker. She likewise prosecuted the art,
and is the only female stucco worker I have met with any account of Rudolfi and his wife took
ser\-ice with Sigismund II., King of Poland, leaving their only (?) son here. Leonardo Ricciarelli,
one of those who worked at the Palazzo Vecchio at Florence, came here in 1 570, and Luca Romano,
who had worked with Primaticcio at Fontainebleau, came here after Primaticcio's death, and I have
found his name as employed in England in 1586.

The English plasterers quickly learned the operative lessons these Italians taught, though they
never learned the skill of their arts of design ; nor indeed was this necessary. The exigencies of
English houses were different from those of Italian palaces, so they fitted their work for its purpose —
a purpose never applied in any other country — that of covering a flat ceiling in a room of moderate
height with a suitable plastered decoration. That this lesson was early learned is shown by some
notes we have of the career of Charles Williams, the first English plasterer of whom we have anj-
record as a practiser of the new art. He had most probably been one of those who were employed
at Nonsuch ; at any rate he had travelled in Italy, and wrote in 1547 to Sir John Thynne, then
engaged in building his house at Longleat, in Wiltshire, offering his services in supplying internal
decorations upon " the Italian fashion " ; and among the papers at Longleat are two letters from Sir
William Cavendish and his wife (Bess of Hardwick), begging from Sir John the use of this " cunning
playsterer," who, they hear, had made " dyvers pendants and other pretty things, and had flowered
the Hall at Longleat," to do like work for them at Hardwick Hall. There is but little doubt the
fragment -of the frieze still remaining on the wall of the old house is his handiwork. If so, the
" Italian fashion " he wrote of is more applicable to the handicraft than the design, and it is not
improbable that the great frieze representing a stag hunt which )-et adorns the Council Chamber
was executed by those who had studied under his direction. Of course, during the short and
troubled reigns of Edward VI. and of Queen Mar\-, when England was in the throes of the inter-
necine strife of politics and religion, but little decorative work was done, nor until the long and more
prosperous time of Queen Elizabeth did the English plasterer have the opportunity of showing his
prowess.

He had not attempted to vie with the more artistically educated foreigners, but had evoked
for himself an especial decoration of his own, based in some degree on the familiar groining which
had strengthened and ornamented the stone roofs with which he was familiar. Geometric rather
than freehand designs were his first essa\-s. These at first consisted of interlacing squares, having
radial ribs from their intersecting points, and as he grew bolder in his work these radial ribs became
arched, and from their junction depended a pendant more or less ornamented, such as you may see
copied, in South Kensington Museum, from a ceiling at Sizergh Hall, Westmorland, where you will

i6 P/nsfcriiii: — P/aiii and Dccomtivc.

find it in conjunction with fine Renaissance inlaid wood work. Frequentl)-, modelled foliage re-
placed these radial ribs, giving the effect of a Gothic diaper to the ornamentation of the ceiling, as
in that at Hurton Kirk. These simpler ceilings relied greatlj- on colour and gilding, and Edmund
Spenser, the great poet of the Elizabethan era, sings in his "Visions of Bellas- " of halls where

" Goki was the parget, and the ceiling bright
Did shine all scaley with great plates of gold ;"

and the ijlasterer and the painter were united, not only in their work, but in their person, — so much
so, indeed, that the elder Companj- of the Painter-stainers was compelled to appeal to the Parlia-
ment in the latter \-ears of the Queen's reign to restrain the plasterers from using oil colours, and
they were ultimatelx', after considerable di.scussion during two Parliaments, confined to the use of
distemper painting onl)-. But it was not the encroachment of the Plasterers' Compan)' by painting
alone which dejjleted the trade of the Painter-stainers. The purity of the white stucco then intro-
duced, and the decline of the media;val sense of colour in favour of this white homogeneous purit\-,
had its effect also, and this was enforced by the richness of the ]j!astcring introduced. The
geometric arrangement was no longer confined to straight lines. Curvilinear, interlacing, and
knotted forms were introduced as at Loselj- (Plate VII.). The ribs were no longer of plain
moulding, but embossed with running ornaments, modelled or impressed, and as the art grew, even
the geometric basis was abandoned, and a free adaptation of scroll work of \er_\- large dimension
was adopted. The ceiling was not sufficient for the plasterer, even though, as at Charlton in Kent,
it was 115 feet in length, but his art encroached on the walls, and a deep frieze, filled with relief
ornament of figure work and emblems, extended itself between the wainscot and the main cornice,
as at Crewe Hall, where some of the friezes are nearlj' 6 feet dee]3, and the Hardwick Hall example,
before quoted, is 1 1 feet deep. With such as these the art of painting could not then compete.

The over-mantels of the large fireplaces were filled with subject work or armorial bearings, and
henceforward the plasterer was the supreme decorator ; in fact, he usur]:)ed the province of both the
painter and the sculptor, and revelled in tlie large mansitjns which sprang up all over the country
during the latter j'ears of Queen Elizabeth's reign and the early ones of her successor. External
walls were sometimes covered with pargetry, like the cottage at Wyvenhoe, detail of which is
shown in Illustration No. 6 ; and the string courses, cornices, and other external architectural
features were covered with piaster as at Hollington, Kent, and Little Charlton, near Woolwich, — in
fact there is hardly a single county in England or Wales which does not )et retain the evidence of
the artistic powers of the plasterer. Some places, notably the older towns, once commercial centres,
but now somewhat decayed in wealth, ha\e hy that absence of growth preserved much of their
wonted glor\- fjr us, such as Yarmouth, which abounds with rich plaster work of the character
you will see on Plates VIII., IX., X.

The early j-ears of James I. were very fruitful ones to the plasterer, and in Bramshill House,
Hampshire, built in 1603, there are several ceilings, one of which you will see on Plate XI. ; but
one of the finest mansions of this time is Audley End, where almost each room exhibits a \-ery
varied design of ver>- noble character. This house was built by Thomas Howard, Earl of Suffolk,
between 1603 and 1616. The principal room measures 66 feet b\- 30 feet, and its ceiling gives its
name to it, for it is divided into thirty-two compartments, each of which is occupied by modelled
groups of fish or other aquatic subjects, hence its name of the '• Fish Room." These subjects are
divided b\- broad flat ribs having ver>- boldlj- arched pendentixcs at their junction, and which are

Jacobean Period.

covered with the most delicately modelled ornament, partly impressed and partly hand wrought.
The stud}-, a room 40 feet by 24 feet, has a singularly convoluted pattern, one quarter of which you
will find on Plate XII., with most delicately wrought pendants of varied design at the principal
points. This design was evidently a favourite one, for there are several replicas of it existing, as at
Charlton in Wilts, and sundry other places, helping to prove that these ornamental plasterers
travelled from place to place, taking their patterns with them. But the triumphant example of the
plasterer's work here is found in the library, a large room 60 feet by 30 feet. This area is quartered,
so that each quarternal cartoon is 30 feet b)- 1 5 feet, and the whole main form is one large oval
interlaced with, and intersected by, other curxilinear lines so beautifully drawn that there is not one
lame or halting one in the whole of this large area— a wonderful piece of setting out, showing not
only great skill in design, but most
accurate eye and hand in its e.xecution.
Interspersed with these fine main lines
is most delicately wrought foliage work,
with here and there a winged fairj- such
as might have been an attendant on
Titania ; indeed, this ceiling has such
wonderful refinement and poetic grace
that it may best be described as a
plasterer's translation of Shakespeare's
"Midsummer Night's Dream." There is
a beauteous variety of detail throughout
the whole, no formal repetition, but a
rhj-thmic balance is maintained, giving
an emphasis and a cadence bej-ond ex-
pression, and I know of no other ceiling
of this date so pure and so restrained.
A much richer, though not so graceful
a one, is found on Plate XIII., from the
state bedroom of Boston Manor House,
showing the main ribs highly decorated,
and illustrating the mode of setting out

such

by quartering. On this ^^

plate is also shown a section of one of

the pendants of the same ceiling (Fig. l), No. 6.— External ri.AsrER Work, \Vy\ emiof, Si.\teemh Centiry.

together with a frieze from Bowery Hall,

Edmonton (Fig. 2). Of the external modelled work done at this time, it may suffice to mention

the fine old house at Maidstone, which bears upon it the date of 161 1, and where large panels

of scroll work, interspersed with the royal arms and the device of the Prince of -Wales, fill in the

spaces between the beams. Bishop King's House at Oxford, 1620, the George Inn at Audle\- End,

and abundant instances exist to prove its popularity.

Scotland ha\ing now annexed the kingdom of England, annexed its plasterers. .At aii_\- rate
their patterns seem to have been appropriated, for they all belong to this epoch, and there does
not appear to be any evidence of a national growth in Scotland, such as exists in England.

Probably the earliest of these Scottish examples is that of Craigievar, Aberdeenshire, which

P/asfcriug — P/aiii and Dtxorative.

dates from 1611, when the castle was purchased by William Forbes, who "having made much
wealth by trading in Denmark," " he plaistercd it \ery curiously," with the result shown on
Plate XI v., adapting the usual pattern, common in manj- parts of England, to the arched and
groined ceiling. Similar ceilings exist at Moray House, Edinburgh, one of which is shown on
Plate X\'. Both of these examples show the ribs enriched with modelled ornament, and give
excellent impressions of the effect of this treatment. A little later example of a similar pattern
comes from W'inton House, Midlothian, done about 1620 (Plate XVI.). The design and details
of all these three are so similar that it is more than probable that the}- are all the work of the
same school of plasterers, whether they be Scottish or English. At Pinkie House there are
many plainer ceiling.s, partaking in form the character of those found in the houses pulled down
in Lime Street, London, and shown on Illustrations 7, 8, 9, proving that there was little or no

difference between the two halves of the king-
dom. Under Charles I. the old st)-le of his
father at first prevailed, and so late as the
Survey of the Manor of Wimbledon in 1649
we read of a room in which " abo\c the wain-
scot is a border of fret or parge work wrought :
the ceiling is of the same fret or parge work " ;
and many of the older houses yet there remain-
ing ha\-c good illustrations of this survival of
the older character. Yet the ad\ance in the
study of Renaissance architecture under Charles
I., greatly due, no doubt, to the influence of
Inigo Jones, reduced this redundance of orna-
ment, and ceilings of a [jlainer character, but
still retaining the ribbed formation, pre\ailed,
such as that shown from Carnock Castle, Stir-
lingshire (Illustration Xo. 10) ; but gradually
e\en these ribs disappeared from the ceiling,
which was once again relegated to the painter
(fostered by the works of Rubens and other
imported painters) rather than to the plasterers ;
but the unsettled state of the kingdom, and the
Puritanic worship of plainness which set in, and continued during the Commonwealth, were well-
nigh destructive to both, nor until the Restoration of Charles II. was either enabled to revive.

Born of a French mother, passing his youth chiefly abroad, the king returned to his devastated
native country without any love for its national arts. The older or the wealthier families were
requisitioned, repudiated, and ruined during the past troubles by one side or the other, and not
unfrequently b>- both, so there was but a mere tradition of the old art left, yet sufficient remained
to resuscitate it in a new fashion. This was enhanced by Sir Christopher Wren's visit to Paris in
1665, where he particularly noticed the plaster work done by \'an Ostel and Anoldino, " plaisters
who perform admirable works at the Louvre," and refers to " the marble meal as the old and still
the modern way of stucco work in Italy." Fostered by its new masters, the art took a floral motive
for its use, and the illustration (Plate XVII.) Mr Millar provides (for the use of which he has
obtained the especial permission of the Lord Chamberlain) is an excellent specimen of the

No. 7.— I'LASTER Ceiling, Lo.ndon, 1620.

Undey the Stuart Dynasty.

plasterer's art of the time. This is from Holyrood Palace, where it forms the ceiling of the principal
staircase, and is about 24 feet square, consequently the figures in the angles representing Fame,
Glory, Force, and Power are rather more than life size. The floral wreathings are full of the most
delicate and beautiful modelling, the work of Italian plasterers, whose names are inscribed upon the
plaster, a fact noticed b\- Mr :\Iillar when as a youth he worked on its repair. At Astle\- Hall, near
Chorley, Lancashire, there is a very fine floral ceiling, enriched with flower and foliage, surmounting
an elaborate frieze and cornice of figures and festoons ; and in the Church of King Charles the
Martyr, at Tunbridge Wells, there is a very good ceiling, with a large hemispherical dome in the
centre, having a ver}- boldlj- modelled wreathage of foliage and flowers in alto-relievo, with cherubs'
heads, palm branches, and conventional foliage in its minor accessories, and an adjacent ceiling,

No. 8.— Plaster Ceiling, I.ime Street, London, 1620.

amongst cherubs' heads and palm branches, bears two dates, 16S2 and 1690. These were done by
John Weatherel and Henry Hoogood, who in those two years were paid ;^I90 for their work.
Similar plaster work, evidently by the same hands, was done at Groombridge Place, in the vicinity.
Of course we have not much in London of the early part of Charles' time— the Great Fire destroyed
the old, and the Great Plague arrested the new; but there is a ver\- beautiful specimen in St
Mildred's Church, Bread Street, the ceiling of which contains a central dome supported upon arches;
the cornice, marking the springing of the dome, has a very rich band of fruit and flowers, the pen-
dentives are filled with well-modelled laurel branches, and rosaces and palm branches fill the panels
in the arches. Once it had a band of cherubs circling round the foot of the dome, but these have
been removed.

/V(rs/('r///p — P/(ii/f and Decani the.

"n — ' — r-rr

.> I .' J I .' I t il J cl J u iJ ,1 t! J y u

One of the most remarkable monuments of the plasterer's art in external work is "Sparrow's
Hdusc," at Ipswich (Plate XVIII.), which was done in 1683. The house itself is about a century
older, and there is very interesting internal plaster work, together with some in an exterior
court, of earlier date, which is very good, but its chief glor\- is on the main front, which was
apparently redecorated in consequence of the visit of " the Mcrrie .Monarch" to Ipswich in that
year. Here we have modelled groups of the four quarters of the globe, with their emblems,
together with a large figure of Atlas bearing the globe itself. There are festoons of foliage,
St George and the Dragon, a grand escutcheon of the ro\-al arms, processional and ])astoral
scenes, making this well-preserved house veritably a national monument; and Ipswich is worthy of
a plasterer's pilgrimage, as he will find much other evidence of the past history of his art and craft
in this quaint old port. French fashions, however, reigned supreme during the latter portion of the
Stuart dynast)-, and the influence of the style of Louis XIV. made itself prominent not onl)- on the
ceilings, but on the walls, where raised plaster panels with ornamental heads and bases began to
prevail. This was stronglj' emphasised by the building of IMontague House, Bloomsbury, the
initiative of the British Museum, by Robert Duke of Montague, who was our ambassador to the

C(nirt of Louis XIV., and who brought
over Pierre Puget from Marseilles for
his architect. Puget was brought up as
a wood carver in a shipbuilding yard,
and decked everything with flowers, for
w hich he largely used stucco. Much of
liis work was delegated to and done by
Monnoyer, a flower jjaintcr and modeller,
and henceforth naturalistically treated
wreaths and festoons of flowers became
the prevailing ornament, often very
delicately modelled in stucco or carved
on wood b\- Grinling Gibbons and his
school, thus creating the so-called "Queen
Anne style," which is much more talked
about than understood, and which really
ran through the reigns of William III. and his successors until George II. Under their influence the
ceilings became divested of other panelling than a broad margin surrounding it, filled with flowing
ornament, and often with rounded or incurved angles ; the cornice became of small importance,
the frieze had disappeared, and a deep cove, plain or ornamental, replaced both. A good example
exists at Drum House, Midlothian, where there is rdso an example of the later and richer form
of this phase. An excellent specimen of this st\'le ajjplied to a \aulted ceiling is shown on
Plate XIX., in the work of Arturi and Baggutti on the ceiling of St Martin's-in-the-Fields, executed
about 1722, and which, apart from the ornamental detail, is an excellent specimen of the plaster
work of the period. Arturi and Baggutti were then the principal workers in modelled stucco in
London, and were greatly emjjloyed by Gibbs, then the most successful pupil of Sir Christopher Wren,
for whom they did .some excellent work at Twickenham and at Cambridge, and who deemed them
"the best" fretworkers in England. At Cambridge they were a.ssisted by Denston, a Derbyshire
plasterer, who afterwards did much work of this character throughout the Midlands. The true
French character of this style will be found on the Plates XX. and XXL, illustrating the ceilings of

No. 9. — I'l.ASTER CkILING, LONDOX, 1628.

The Georgian Period.

iiiii

llllii!;-l'ffiiiiliiijiiii!iiia|i!i!iii!i;i!iyiw^'$^^

i;"^;'i;:<M

No. 10. — Plaster Ceiling, Carnock Castle, Stirlingshire, 1640.

the Queen's bed-chamber and the Salon de Medailles at Versailles, and a good example of the
Italian translation of it in that of what is now the Queen of Italy's study at Turin (Plate XXII.).
Naturally the Louis XV. style followed that of Louis XIV., a more flowing and less architectural
distribution of ornament took place, and the plain field of the ceiling became a more important
feature, the ornament being driven into the corners and in the centres, such as you will see in
Plate XXIII., where is illustrated the ceiling of a room in Milton Hou.se in the Canongate at
Edinburgh, and of which type many not long ago existed in London. A combined elevation and
profile of the cornice of this ceiling are shown on Illustration Xo. 11. In such as these the trophies
and medallions taken from the illustrations of such works as Fontaine's Fables, and other works of
French origin, were frequenth' introduced in cast plaster, to the detriment of the plasterer's art, as
the moulds were, like their subjects, imported also; nor were these the only cast portions, but the
repetitive cur\-es, " mutton chop bones," as they used to be called, were cast in sizes, and used to
form the principal cartouches and leading lines, until their monotony called forth Ware's satire upon
them, and Isaac Ware, who began his life as a chimney sweep, became a ro>-al architect, and, as the
arbiter of taste, published his " Compleate Body of Architecture" in 1725. In this he .say.s, "A
ceiling straggled over with arched lines and O, C's and C's and tangled semicircles may plea.se the
light eye of the French, who seldom carry their obser\'ation further than a casual glance," and
further tells us that " the French have furnished us with abundance of fanciful decorations for
the.se purposes, little less barbarous than the Gothic"! Such an eminent dictum brought forth
some English designs to amend this barbarity. So in 1773 Matthias Darlej- brought out his book

f/nstcrim: — f/ai/i and Decorative.

of dcsi^Mis in his " Comijlctc Body of Architecture," but by this time so lost was the ori^nnal plaster-
work character and function that the same design \\as deemed equall>- applicable to painting or
sculpture, and is often described as one "to be worked in stucco, carving, or paint." This was
followed b\- Columbani's " New Book of Ornaments commonly worked in Stucco, Carving, or
I'ainting"; and Chippendale, Pether, Lock, and even Batty Langley brought out books of designs
for plasterers and carvers, setting a ver\- reprehensible fashion, too much followed nowada>-s, b>-
divorcing design from craft, and b\- no means improving either. The ])lasterer's art thus became
thoughtless and absurd, having no specific character of its own. and the dilletanti would have none
of it. Simple purity became grateful to them because it was not ridiculous.

Hence came in those coffered ceilings, such as that at Sir Mark I'leNclell's house at Coleshill,
Berk.shire (Tlate XXIV.), in which there is a certain amount of nobilit}-. What ornament there is,
it is true is onl,\- cast work, but the coffers are deep, and give good play of light and shade, and are
rigorouslj- architectural, eloquent of the T-square and the drawing board, and redolent of precedents.
These were prcmonitorj- of the death of the artistic plasterer. He borrowed, not made, his designs ;
he cast his ornaments, not modelled them ; he kept a stock of moulds w hich he used more or less
inappropriately, fitting his borrowed design to his ornament rather than designing his ornament to

fit an original one, and his work
T aTfil^g^-m^m.. ^^^-^_^^^ ^^^^ -■ .-. -...^ .-. ^ became dull, flat, stale, but by

no means to him unprofitable.
Curiously enough, the very
ruins of old Rome, which two
centuries before had given such
,111 impetus to the plasterer's
art, led to its extinction, for
about the middle of the eight-
eenth century there was a de-
cided feeling for the exhuma-
tion of the buried antiquities
of Rome, and their study ; and
the publication of such works as Cameron's " Baths of the Romans," Ponce's " Bains de Titus,"
together with the host of works treating of Roman architecture, now had an enfeebling effect after
the freedom and breadth of ornament they had created. Exceedingly pretty, they pleased the
|jublic taste; simple in their elements, they were easj- to design; and full of work, thej- gratified
their maker ; and with here and there a cast cameo or a painting b)' Cipriani or Angelica Kauffmann,
the)' were refined and delicate, such as you will find that from the Queen's room in Old Buckingham
House (Plate XXV'.) ; but verj- little work was left to the art of the plasterer. He chiefly cast the
models another artist had made, for when his ornament became so monotonously repetitive there
was no reason wh\- he should model it separately. If you examine the ceilings from Kedleston
(Plate XXVI.), Dublin (Plate XXVII.), or Pergolesi's design for a wall decoration (Plate XXVIII.),
j-ou will at once see how small amount of varietj' there is in the elements of their composition.
Pergolesi was brought from Italy by Robert Adam as his decorative "ghost," and brought his
" pastiglio," or paste composition, with him. And now it is no longer the plasterer who adorns the
house— it is the " compo man "—again an Italian, so that the race and the place which caused the
resurrection of plaster modelling caused also its death. Adam, indeed, " brought death into the
world," so far as this fine old art and craft is concerned. And yet there were clever plasterers

No. II.— Elevation ani> I'rofile of Cornice, Mii.tox House.

Late Workers and Examples. 23

assisting at its obsequies. Arturi, whose work we saw in St Martin's Church, Hved till 1769. We
had Xaldini and Richter working here in 1770. Thomas and Charles Clark did some admirable
work both in England and in Ireland from 1760 to 1780. Collins did much work for Sir William
Chambers. Joseph Rose, who probably wrought on the Queen's room shown on Plate XXV., and
was afterwards employed at Carlton House and Whitehall ; and John Papworth, who died in 1799,
and was almost the last of a fine old race of workers. Most of these plasterers were really artists,
and their modelled medallions and individual bits of design are well worthy of study ; but the vain
repetition of " ornament " by the )-ard ruined them and the art expired, and perhaps the very last
stucco modelling in situ done in London was on the ceiling of Hanover Chapel, Regent Street.

It may be thought I have in this short sketch of the long history of " Plaster Work, Plain and
Decorative," dwelt too much on the higher development of it, but you must recollect that the higher
development brings up the lower with it, and that all rise alike, so that in getting the best of one
you get the best of both. Therefore, as time and space preclude the writing of an exhaustive
history, I have onl\- roughly outlined some of the prominent features of its interesting past. The
principal object of this chapter is to show what great artists have aforetime been the votaries of art
in plaster work, and to induce those of our own day to try and revive the higher ambitions of the
craftsmen of an art and craft which has such an important history, to raise it again to its former
eminence, and to be no longer content with covering the sins of the "jerry-builder" with a
charitable but very plain coat of indifferent plaster.

G. T. R.

CHAPTER I.

HISTORICAL PLASTERING IN ENGLAND. SCOTLAND, AND

IRELAND.

Primitive— MEDi.tVAL— Elizabethan-— Jacobean— Seventeenth and Eighteenth Centuries— Notes on
Old Materials and Manipulation— Plasterers' Wages, Hours, Victuals, and Drink defined
HV various Kings and Acts.

1'KIMITI\ 1'.. — The primitive mode of plastering practised in Great Britain and Ireland, before lime
plastering came into general use, was with clay, mud, or sticky and unctuous earth. The rudest
forms of daubing or plastering were structures erected of wattles, and daubed over with mud to
keep out the cold and wet. Domestic buildings erected in this manner were in general use in the
time of Henr)' II. The Devonshire "cob," a class of building not \'et e.xtinct, is a fair sample
of the ancient fashion of daubing or plastering practised in this country for many centuries. In
the twelfth centurj-, N'echam in his writings refers to "smoothing the surface of the walls by
the trowel." According to Roger Hovcndcn, the English monarch in 1172 erected a royal
residence with uncommon elegance. The London Assize of 11 89 mentions "mud plasterers,
lurchers " {i.e., cob wallers) ; that of 1 2 1 2 plasterers and whitewashers (dealbatores).

After the fire, in the year 1 212, which destroyed London Bridge, and a number of houses,
the bridge and the houses being made of wood, King John issued an ordinance in which
the following items appear: — "All shops on the Thames be whitewashed and plastered within
and without. All, houses which till now are covered with reed or rush, which can be plastered,
let them be plastered within eight da\-s, and let tho.se \vhich shall not be plastered within
that term be demolished bj- the alderman and lawful men of the venue. And let all houses
in which brewing or baking is done, be plastered and whitewashed within and without, that
they maybe safe from fire." The same ordinance fixed the rate of wages fir whitewashers and
mud plasterers at 3d. per day with keep, or 4d. without keep. The mud plasterers were those
who filled the spaces between the timber frames w-ith mud, clay, and straw, which was afterwards
whitewashed.

In the thirteenth and fourteenth centuries the plasterers proper and the daubers formed
two distinct clas.ses of workmen. The daubers were simply the la\-ers on of a mi.xture o^ clay
and mud to the timber framework. The dauber or inferior plasterer of the fourteenth century
received sd. per day from Easter to St Michael, and 4d. per da)- for the remainder of the

Mediceval. 25

year if at work. The daubers' labourers who attended them, as well as the tylers, received 3id.
per day for one part of the year, and 3d. for the other part.

In the thirteenth century lime was sold by the bag and cwt. as at present. It was mixed with
sand, and in some cases with pounded tiles. In 1282, for repairs of Newgate, the following items
appear: " In the purchase of broken tiles, 2s. 4id. In four score and four bags of lime, /s. In
twelve carts of sand, 2s." The pounded tiles in the mortar found in Mediaeval buildings may
have led to the belief that they were of Roman origin. The architect has another item for repairs
at Newgate at the same period, thus : " In plaster of Paris, bought to plaster the windows and the
chamber where the Justices sit within, 13s. 4d. In wages of a plasterer and his servant, four
days, 2s. 8d."

At the end of the twelfth and the beginning of the thirteenth century, the application of
impressed plastic work for the purposes of architectural decoration was frequent. Delicate
ornaments in low relief were impressed by means of wooden or metal tools on the moist plaster,
which was afterwards painted and gilded.

MedL€VAL. — The INIediasvalists did good plaster work. The rubble walls and vaults of
their churches were plastered and decorated. At Netley Abbey the vaults of rubble are covered
with plaster the remains of which are still visible. At Little Bra.xted Church, Essex, an edifice in
the Transitional st)-le, a thin coating of fine plaster, ^ inch thick, is found on the walls, showing good
workmanship. Examples are still found at Eynsford in Kent, and at Oxford, where gable ends
are covered with moulded plaster work, stamped diapers of geometrical design being slightly sunk
on them. In Lancashire and Sussex half-timbered houses were plastered between the timbers
with rough-cast made of lime, hay, coarse sand, and pebbles. An interesting discovery has lately
been made in the Parish Church of Avebury, in Wilts. The outside of the walls of the nave
above the aisle roof and around a circular window were found to be plastered, and on removing
a portion of the thirteenth-century aisle wall, the plastering was found to be carried through (but not
bound into it) the connection of the walls around the quoins, which were found to be of the Saxon
long and short work. This plaster had not been disturbed in adding the aisle wall in the
thirteenth century.

There is an interesting agreement of the reign of Edward II. '1317; concerning the plastering
of the Hall of John de Bretagne, Earl of Richmond. Thus runs the agreement of the master
plasterer of the fourteenth century : " Know all men that I, Adam le plastrer, citizen of London, am
held bound to Sir John de Bretagne, Earl of Richmond, to find plaster of Paris, at my own proper
charges, good and sufficient, without default, proper, for the hall of the said Earl, and also that I
will competently, at my own proper charges, plaster and complete the said hall, and will repair the
walls of the same with the said plaster, well and befittingly within and without, as also the tewels
(the louvres or flues) to the summit, in such manner as befits the repair of the hall aforesaid ; and
this I will do for 24 pounds sterling, which m\- lord the said Earl has paid to me beforehand.
Faithfully to perform the which work within eight weeks from the day of the Hol>' Trinity next
ensuing, I do bind myself and all my goods, movable and immovable, namely my lands, houses,
and tenements, within the city of London being, to .distress in part of any bailiff of our lord the
King," &c.

In London in the time of Edward III. (1350) the plasterers were bound to take no more for
their working day between the feasts of Easter and St Michael than 6d. per day without victuals
or drink, and 5d. per day for the remainder of the \-ear. Upon feast da>-s when they did not work
they received no wages.

26 Plastering— Plain and Decorative.

A kirihcr mention of tlie jjlasterer or dauber is found in an account of mone>s expended for
the repair of a house in the parish of St Michael's, CornhiU, in the reign of Edward III. (1359),
vi/. : " Kor 12 cartloads of lorn (loam), 4s. ; for 9 sacks of lime, i8d. ; for 3 cartloads of sand, I2d. ;
for one workman's wages for daubing, 9 daj-s at /d. per day, 5s. 3d. ; for his man the same time at
5d. per day, 3s. 9d."

A"ain, in an account of expen.ses incurred b_\- the representatives of the Cit)' attending the
Parliament in 13 Richard II. (1389), the plasterers or daubers put in an a])i)earance : "For
timber and carpentry, tilers and daubers, in preparing the house for their lodgings, as well as the
chambers as the hall, buttery, kitchen, and stables for horses ; and for making stoles and fourvics
(stools and forms) throughout, and for carting out the rubbish, such house being quite ruinous ; as
also for payment made to the goodman of the house for said lodging, £t. 9s."

An example of old plaster work, as treated for external work, is to be seen in an ancient house
at Clare, in Suffolk (Plate \'I.). This fine old half-timbered house, according to the date in the
front, was built in 1473. Its most remarkable feature is the quaint treatment of the plaster work,
which is in high relief, some of the enrichments rising 2 inches from the ground surface. Beneath
the oriel bay on the first floor are two small figures supporting a shield charged with the arms of
X'erdun. Beneath a window at the side of the house is a winged animal. The scroll work on this
level, also that above and around the oriel baj-, appears to be all hand work.

The following reference to external stucco work is taken from the ''Vulgaria" of Hormann,
dated 1519, the text of which is in Latin: "Some men will have their walls ])lastered, some
pargetted and whytlymed, some rough caste, some pricked, some wrought with plaj-stcr of Paris."

At Newark there is a fine example of exterior decorative plaster work on the front of a house
in the Market Place, which was built in the fifteenth century. The most ])rominent feature is a
series of niches and plaster figures.

During the reign of Henry \TI1., the pupil of Wolsey, and the rival of PVancis, many
Italian stucco workers found their way into this country. Nor was there any countr\- in Western
Europe more fitted to receive their work than was our.;. The half-timbered framework houses,
with their large surface of plastered panels, seemed purposely prepared for raised plaster work,
and what we call pargetry at once established its footing. Heraldic achievements, foliage, and
figure work appeared in abundance, and our ceilings were adorned with moulded compartments,
filled with devices and quaint rebuses, and hung with flowered jjcndants, all modelled b\- hand ;
and above all rose Nonsuch Palace, of which unfortunate])- no relic and limited records remain.
Nonsuch was begun about 1527, and although the embellishment of this sumptuous palace was the
hobby of the last ten j-ears of King Henry's life, it was not finished at his death. Its completion
was due to the Earl of Arundel, in Queen Mar\'s da\s, to whom English art owes so much. Built
according to the custom of the country, of timber framing, it was well suited for the dis])lay of the
then newest fashion in decorative art. Nonsuch Palace obtained a great reputation for luxury
and magnificence, and was frequently visited and mentioned by many celebrities. Leland says
of it :—

" Hanc quia non habenl siinilem laudare Britanni
Srcpe Solent nuUique parem cognomine dicunt."
(" Unrivalled in design, the Britons tell
The wondrous praises of this nonpareil.")

Queen Elizabeth was a frequent guest there. Hetzner, a German traveller, who v:.;;'.2:l t'.ie pr.'.aco
in Elizabeth's time, saj-s that it was built " with an excess of magnificence ar.d elegance, even to

Sixteenth Century. 27

ostentation. One would imagine everything that architecture can perform to have been employed
on this one work. There are everywhere so many statues that seem to breathe, so many miracles
of consummate art, so many casts that rival even the perfection of Roman antiquity, that it may
well claim and justify its name of Nonsuch, being without an equal, or, as the poet sings :—

'This which no equal has in art or fame,
Britons deservedly do Nonsuch name.' ''

The Duke of Saxe-Weimar, who visited Nonsuch in 1613, tells us that the labours of Hercules
were set forth on the king's side, the queen's side e.vhibiting all kinds of heathen stories, with
naked female figures. Pepys, who visited it in 1665, describes all the house on the outside filled with
figures. Changing hands frequently, despoiled as a royal residence during the Parliamentary
wars. Nonsuch fell into decay. Evelyn saw it when neglect and vandalism had brought it well-
nigh to ruin, and yet he was filled with admiration with what remained. " I took," he says, "an
exact view of the plaster statues and Ims-relievos inserted between the timbers and puncheons of
the outside walls of the court. I much admired how it had lasted so well and entire from the time
of Henry VHI., exposed as they are to the air, and pity it is they are not taken out and placed in
some dry place — a gallery would much become them. They are inezzo-relievos the size of life.
The story is of heathen gods, emblems, and compartments."

The last mention of this palace occurs in James U.'s time, when P. le Neve, in his copy of
Aubrey's Surrey, says he then saw it, and that it was " done with plaster work made of rye dough
very costly." It is very probable that rye meal was mixed with the plaster, as the gluten would
retard the setting, and the admixture work freely, and eventually become hard. This magnificent
palace of plastic art, which introduced decorative modelled stucco work into England, may be
justh" termed the " plasterer's pride and pleasure."

The amount of royal patronage exalted the plasterers' craft mightilj-, and from this time
downwards until the end of the last century the plasterer was one of the most fertile of our art
workmen, and one of the best paid. In Edward VI. 's time (1547-53) his wages were lid. per day,
painters and carpenters only earning 6d. and 7d. per day, showing the superior estimation in which
the plasterer was held. In fact, during the latter part of the sixteenth century, and throughout
the seventeenth centur\-, there was scarcely a house of any import in the country which had not
its rooms adorned with modelled plaster work — not merely the ceilings, but frequently the wall
space between the high wainscot dado and the cornice was so decorated, whilst over the mantel-
piece was often some large allegory or heraldic achievement wrought in stucco ; and what is parti-
cularly interesting is, that in spite of all the Italian teachers who inaugurated the art, the English
plasterer never became that " Diavolo incarnato, Inglese Italianato," but retained a national art
speech — somewhat rough at times, it may be, but always purely vernacular.

In 1501 a charter was granted to the plasterers' craft by Henry VII., and the arms of the
Plasterers' Company were granted by Henry \'III. in 1546. The following e.xtract from the charter,
if put into force in the present age, would render the existence of the jerry worker and scamped
work impossible : " The right to search and try and make, and exercise due search as well in,
upon, and of all manner of stuff touching and concerning the art and mystery of pargettors,
commonly called plaisterers, and upon all work and workmen in the said art or mystery, so that
the said work might be just, true, and lawful, without any deceit or fraud whatsoever, within the
city of London or suburbs thereof" In those da>-s the different parts of a building were carried out
by master craftsmen. This fact is borne out by the charter granted by Charles II., which forbade any

28 Plastering — Plain and Decorative.

person from carrj-ing on simultaneously the trades of a mason, brickla>-er, and plasterer, and also
forbade any person to exercise or carry on the art of a plasterer without having been apprenticed
seven years. Search daj-s, as described in the charter, were annuall)- appointed up to 1832, and
fines were inflicted upon offenders for using bad materials and bad workmanship.

At Boiling Hall, Yorkshire, one of the plaster ceilings is said to be fully four hundred jears
old, and is considered to be one of the most remarkable specimens of the work of the period. The
ornamentation, which is in high relief is most quaint, its principal characteristics being heads of
dogs, bears, and foxes, from the open mouths of which issue branches of various fruit trees, different
kinds of birds and animals being inserted here and there. The cornice is of considerable depth,
quaintly enriched with heads and fabulous animals. The drawing-room ceiling, which is of later
construction, is interesting for its free and fine treatment. At Xettlecombe, the scat of the
Trevel)-ans, built in the fifteenth century, the great hall has an elaborate ceiling. The manor-
house at Quantockshead, Somersetshire, built in the sixteenth century, is decorated with rich
plaster friezes and ceilings. The quaint example of external plaster work on the exterior walls of a
cottage at Wyvenhoe, near Colchester, was probabl)- executed in the first part of the sixteenth
century. A part of this work is illustrated in Chapter I. This is taken from " Architecture of the
Renaissance in England," by J. A. Gotch, F.R.I. B. A.

Some curious entries are contained in the register of St Benet's Church, Gracechurch Street,
London, one of Sir Christopher Wren's buildings re-erected after the Great Fire. Thus at the
accession of Queen Mary in 1553: "Paid to a plasterer for washing owte, and defacing of such
Scriptures as in yo. tyme of King Edward YI. were written aboute the Churche and walls, we be
commanded to do so bj- ye Right Honor. }'e Lord bishopp of Winchester, Ld. Chanr. of England,
3s. 4d."

The Duke of Wurtemberg, the " Cosen Garmobles " and " Duke de Jamaree " of Shakespeare,
who visited England in 1592, was ravished with the plaster ceilings at Theobald's, &c. Once the
interior plaster work glowed with gold and colour.

Shakespeare, that mighty master of man's mind and manners, mentions the [plasterer, and
various kinds of plastic materials used in the seventeenth and preceding centuries. In " Henry VI.,"
Stafford says to Jack Cade, "Thy father was a plasterer." In "A Midsummer Night's Dream,"
Bottom says, "And let him have some plaster, or some loam, or some rough-cast"; and again,
" Would }-ou desire lime and hair to speak better? "

An old .system of plastering, known as pargetting, was once very general. The word " parget-
ting," although now seldom used except by bricklayers for the coarse plastering inside chimney
flues, formerly signified plaster work decorated by means of stamps, the soft plaster being stamped
or pressed to form repeated designs. Sometimes a happy combination of stamped and hand work
was used for both exterior and interior plaster work. This work is sometimes called " parget work."
The Elizabethan half-timbered houses exhibited on their exteriors ornamental pargetting, displaying
small figures and canopies surmounting them executed in plaster work. Many specimens of old
plaster work are found to contain r\-e-straw, to give it tenacity. Another kind has been discovered
mixed with fibre and reeds, which was commonly used in the sixteenth century.

Pargetting is mentioned in the "Hist. Dunelm." (1450), as follows: "Johanni Bevis, pro
pargetting and blanchyng, Vs." " Blanchyng " probably means cleaning or whitewashing. Bishop
King's House at Oxford is a well-preserved example of figure and pargetted work. Also at Banbury,
Oxfordshire, there is an ancient example of parget plaster work. The ancient house at Clare,
previously mentioned, is a combination of pargetting and hand work. Other examples are to be

Sixteenth and Seventeenth Centuries. 29

seen at Parham Hall, Lavenham, Suffolk. In the "Survey of the Manors of Wimbledon" (a.d.
1649) is an entr\- which reads : "Above which (waynscot) is a border of fret or parge work wrought,
having therein set eleven pictures of very good workmanship ; the seiling (ceiling) is of the same fret
or parge work."

Elizabethan. — In the Elizabethan and subsequent periods plaster work was used largely
in ceiling, wall, and chimney decoration. During the reigns of Elizabeth and James I. a
transitional style between Gothic and Classic was developed. This style was employed in some of
the most stately houses in the United Kingdom. There arose such mansions as Hatfield, Longleat,
Burley, Audley End, Crewe, Littlecoats, Wilts, Chatsworth, Haddon, Hardwick, Blickling Hall,
Bramshill House, Ruston Hall, and man)- others, wherein may be found rich and rare examples of
plaster work, showing great excellence in design and workmanship. The ceilings are usually divided
by intricate geometrically formed panelling, ornamented with foliage, heads, animals, swags, ribbons,
shields, pendants, drapery, bands, and man\- other de\ices.

Sir Paul Pindar's House, London, built in the reign of Queen Elizabeth, contains some glorious
old plaster ceilings. These ceilings abound in the richest and finest devices. Wreaths of flowers,
panels, shields, paterae, bands, roses, ribands, and other forms of ornamentation are charmingly
mingled, and unite in producing the best and happiest effect. One of them, which is all but perfect,
consists of a large device in the centre representing the sacrifice of Isaac, from which a most
exquisite design radiates to the very extremities of the room. In general, however, the work
consists of various figures placed within multangular com]:)artments of different sizes, that in the
centre of the room usually the largest. The projecting ribs, which in their turn enclose the
compartments, are themselves furnished with plentiful ornamentation, consisting of bands of oak
leaves and other vegetable forms, and in several instances ha\e fine pendants at the points of
intersection. The cornices consist of a rich series of highly ornamental mouldings. Every part,
however, is in strict keeping, and none of the details surfeit the taste or weary the eye (Cassell's
" Old London ").

Losely House, near Guildford, the seat of Sir James More Molyneux, erected 1 562, contains
some good plaster ceilings. Plate VII. shows a portion of one of the bedroom ceilings. The pattern
is about 5 feet square before being repeated, and the panels are enriched with the moorcock and
moorhen, badges of the More family. The mouldings are about 8 inches deep, and the pendants
2 feet. This is in great contrast to our modern bare whitewashed bedroom ceilings.

A fine example of external plaster work is the "Ancient House" at Ipswich, erected in 1567
(Plate XVHI.). Although built in Elizabeth's reign, its chief glory is Jacobean. The royal arms,
with CIIR. in the centre, form a conspicuous feature, while a surrounding of birds, fishes, and musical
instruments, together with figures representing the continents, enriched by swags of flowers and
fruit, completes the harmony of the composition. In another part Atlas supports the world. St
George vanquishing the Dragon is boldly depicted on one of the gables, and Phillida and Corydon
adorn another side. A finely modelled triumphal procession enriches the side of another gable.
The whole is probablj- hand wrought in situ. The Old Assembly Room in the same town has
likewise some fine examples of hand-wrought plaster work. Mr G. Bedingfield, of Ipswich, who has
repaired portions of both the above, says that the stucco is still of an extremelj- hard nature,
although it has been exposed to our variable climate for over three centuries.

Great Yarmouth is rich in fine and well-preserved examples of decorative plaster work, which
were executed in the Elizabethan and Jacobean periods. There is a similarity of design in some of
the ceilings, especially as regards the loops at the intersection of panels. The Star Hotel, which was

T,o Plastering — Plain ami Decora live.

built in the reign of Queen Elizabeth, contains several decorative ceilings. The most notable is the
Nelson Room ceiling, which is divided by flat enriched bands into six flat arched bays, which are
adorned with ribbed mouldings, foliage, and pendants. The Qua)- is the centre of most pleasing
plaster work. On the south side of the Row fronting the Quay is an old hou.se, now divided into
two residences fXos. 46 and 47), which was probably built in 15S0. One of the ceilings is adorned
with mouldings divided into compartments, in which are various devices. One represents Noah's
Ark, with the dove returning with, an olive branch. Another is the figure of Neptune bestriding a
sea-horse. The beam running across the ceiling is enriched with fleur-de-lis, and numerous masks
of the human face adorn the sides. The fine old " Ancient House," No. 4 South Quay, was built
about 1596. A portion of the drawing-room ceiling is shown in Plate VIII. This room is 30 feet
by 20 feet. A peculiar feature in this, as well as in the others, is the interwoven mouldings, w hich
form knots and loops at the intersections. This ceiling is divided into fifteen separate compart-
ments. In an old house at the south-west corner of South Qua)- there is a very rich and elegant
pendant ceiling (Plate IX.), e.xhibiting in the centre compartment the arms of James I. It will be
observed that a mistake has been made in rendering the motto at the foot of the ro)-al arms. It
.should be the beginning of Psalm Ixviii. (" Exurgat Deus dissipentur inimici "). The pendants at
the intersections of the ribs are singular, each having on one side an angel with extended wings. In
an upper chamber there is a very rich ceiling, profusely adorned with fruit and flowers. There is
another curious ceiling (Plate X.) in a house in the same Quay. It appears from the design to be
coeval with No. 4 South Quay. The design is somewhat similar, especially at the looped mouldings
and the manipulation of the enrichments.

J.\C0lsr..\N. — At the beginning of the seventeenth century the plasterers apparent))- had
taken so much upon themselves that an Act was passed, in the first year of King James,
forbidding plasterers to do any painting within the city of London or in its suburbs, and restricting
them to the use of some few distemper colours only. The painters did not gain much by this, for
gradually painted work declined, whilst modelled work still continued in the ascendant ; but during
the troublesome times of the Commonwealth it fell into disuse. With the Restoration came in the
flowing rococo ornaments of French and Italian character.

A well-known writer states that "during the end of the sixteenth centur)-, and throughout the
seventeenth, there was scarcely a mansion in England and Scotland which did not exemplify the
plasterers' craft outside or in, and often both."

In 1547, a Charles Williams, as already mentioned, is described as being an English stucco
worker of renown. He was employed by Sir John Thynne in the decorations of the new house at
Longleat. His fame as a stucco worker evidently spread, for Sir W'illiam Cavendish and " Bess of
Hardwick," his wife, being at that time bu.sy at Hardwick, wrote to Sir John requesting the use
of this " cunning ]jlaysterer," who they hear had made " dyvers pendants and other pretty things,
and flowered the Hall at Longleat," to do like work for them at Hardwick. Probably the frieze
still to be seen on the ruined wall of an upper room in the old house is his work. It was more in
the curious and cunning distribution of formative panelling than in figure modelling that the
Englishman distinguished him.self. Our native craftsmen seem to have developed a ceiling
treatment for themselves, in no waj' founded on Italian tradition or practice. Using the arrange-
ment of the fan-tracery of the Late Perpendicular Gothic as a model, they founded an entirely
new treatment of ribs and pendentives, often of most intricate geometric arrangement.

Bramshill House, Hampshire, the seat of Sir John Cope, Bart., dates from 1603. The drawing-
room ceiling, a portion of which is depicted on Plate XL, is a fine example of the Elizabethan

Seventeenth Century. 3'

period. An uncommon feature is the introduction of narrow ribs, which are interlaced through
the larger ribs, forming a separate design, j-et harmonising well with the others.

There is some quaint old plaster work in Chester, notably on the exterior of Bishop Lloyd's
House. Some of the panels represent various subjects from the Old Testament, also the arms of
James I.

Audley End, Essex, built about 1610, contains some of the most exquisite examples of plaster
work in England. The portion of one of the ceilings shown in Plate XII. is remarkable for its
most beautiful, quaint, intricate, and ingenious design. No part of the figure is repeated, and no
two curves are alike. The figure, as marked, is 20 feet by 12 feet before being repeated.

The hall ceiling (Plate XIV.) of Craigievar, Aberdeenshire (161 1), is a rare example of arched
work. A finely designed ribbed pendentive depends from the centre of the vault, while two smaller
ones depend from the centres of the halves of the ceiling. The panels are enriched with coats of
arms, foliage, &c. The general design is somewhat similar to the ceiling in Moray Hou.se.

Moray House, Canongate, Edinburgh, built in 161S, has rare examples of plaster ceilings.
The one shown in Plate XV. is an excellent example of vaulted work. It is beautifull)- panelled
and enriched. The main panels terminate with bold pendants.

There are some fine examples of stucco work at Hardwick Hall, Derbyshire. They consist of
fine ceiling and hand-modelled stucco work on the chimney-pieces, and in the great gallery there
is a fine frieze 11 feet in depth, all modelled in situ. It represents hunting subjects full of men,
animals, trees, plants, &c. When Bess of Hardwick built the new house between the j-ears 1590 and
1597, she left the old one to decay ; yet there is in one of the rooms of that old roofless house a frieze
similar in design to that in the new one, which has stood exposure for many generations without
showing an\' signs of decaj-, good evidence of the durability of stucco. There is some modelled
stucco at Haddon Hall. Over one of the chimne}--pieces is a quaint representation of Orpheus in
hand-wrought stucco.

Corsham Court, Chippenham, built in the seventeenth centurj-, contains some fine examples of
stucco work done in the Elizabethan stj'le. In one room there is a curious cornice, consisting of
one hundred and sixty heads in basso-relievo, and all different.

In the Cotswolds there are some examples of what, in a sense, may be classed as constructional
plaster work, and termed "wattle and daub." This is a rough framework of timber, covered with
interlaced wicker work plastered on the outside face. The floors are pugged with lime and chopped
straw. In the same district there are some stone buildings erected in the seventeenth centur\-.
They are plastered in an original way by leaving the dressed stone work exposed.

There is a curious old plaster ceiling in the staircase at Quidenham Park, Norfolk. This
ceiling is remarkable for its fine foliations, and having in the centre a ship pendant, dated 1619.

Illustrations Nos. 7, 8, and 9 show portions of plaster ceilings of geometrical design in old
houses in Lime Street, London, which were built about 1620, and were recentlj- dismantled for street
improvements. No. 8 shows elevation of the cornice and section of the ceiling through A B.
Chimney-pieces and wood cornices from the same houses are now exhibited in South Kensington
Museum.

Winton House, Haddington, built in 1620, is situated near Edinburgh. It was designed and
built b\- William Wallace for the Earl of Winton. Wallace was appointed master-mason to the
King in 161 7, and a burgess of Edinburgh in 162 1. The portion of the drawing-room ceiling
(Plate XVI.) is remarkable for its great variety of well-modelled panel ornaments, which include
coats of arms, crowns, monograms, figures, cherubs, and many other devices, and foliage. A

32 Plastering — Plain and Decorative.

peculiar feature in the geometrical design is the different divisions of the four oblong panels at the
sides of the square panels, being alternately divided by circular and straight ribs. The figure is
repeated six times in the length of the room, the whole forming a beautifully decorated ceiling.
This room is about 45 feet bj- 26 feet.

The ceiling of the State bed-chamber at Boston Manor House, near Brentford, built in 1623,
portrayed in Plate XIII., is peculiarly characteristic of the Elizabethan style. There is another
ceiling, larger and more elaborate than the one here given, in the .same house. The princijjal
figures which adorn the panels of this ceiling are personifications of the five Senses ; the four
Elements ; the three Christian graces. Faith, Hope, and Charity ; War and Peace ; Peace again,
and Plenty. In one of the panels the date 1623 appears, and in a corresponding panel are the
initials M. R. The extraordinary number of panelled ceilings and cornices with enriched friezes in
old houses of the date of Elizabeth, James I., and Charles I. and II., are remarkable for their fine
plaster work. The plaster friezes are adorned with shields, festoons, foliage, and figures of the
human form ; also with simple designs of strap work, with foliage and fruit.

Seventeenth .\ni) P^iohteenth Centuries. — Holyrood Palace, Edinburgh, was
erected by James IV. in 1525, but the portion forming the quadrangle was only built
during the reigns of Charles I. and II. Holyrood Palace contains many fine old plaster
ceilings, some of which were done b>- l-'iench plasterers brought over by James I. It was
during the reign of Charles II., about 167 1, that the stairca.se ceiling (Plate XVII.) and
some others in the Palace (finer than this) were done by Italian plasterers, or artists, as they
then were (entitled to wear ruffled shirts, lace, and to carry swords) — gentlemen of the " Minor
Arti," as the Italians name them — and who travelled as the carver masons did, from job to job.
The ceilings in Holyrood done by these gentlemen plasterers were modelled i)i situ while the
plaster was still soft. Probably they used size water or some such material to prevent the plaster
setting too quickly. The plaster was evidently gauged with lime putty, also mixed with hair,
a greater portion of j)utty and hair being used for the lower stratum, and decreasing as the work
proceeded to the finished surface. The work is obviously modelled /;/ situ. It has a relief and
variety of detail such as could onh' be got by hand. Tool traces and the workers' names are
visible in parts, and the work is still without a sign of flaw or crack. There are two quaint old
buildings to be seen at Saffron Walden, Essex. They are interesting examples of old external
plaster work. There is no definite and reliable information to be obtained as to their early history.
On one of the gables is the date 1676. On another gable are to be found some crude but curious
figures standing in bold relief in the plaster work, one armed with a spear and the other with a
club. The walls are also decorated with rough quaint plaster work. There is a striking resemblance
in the architecture to the ancient house in Clare, Suffolk. Plate XIX.* depicts a portion of the
plaster ceiling and walls taken from the gallery in St Martin's-in-the-Fields, Trafalgar Square,
London. This beautiful church was built in 1722, and designed by James Gibbs, a celebrated
architect, born at Aberdeen in 1674. The internal effect is very fine from its spaciousness,
stateliness, and ornamental treatment. It is divided into nave and aisles by a range of four
Corinthian columns, and two pilasters on each side. Each column supports a block entablature,
and from this springs a semi-elliptical ceiling over the nave. The vault is pierced transversely
above the columns by semicircular arches springing from column to column. At the back of the

* This plate, from a photograph taken for " London Churches of the Seventeenth and Eighteenth Centuries,"
edited by G. H. Rirch, F.S..\., is reproduced by permission of the pubHsher, Mr B. T. Batsford.

Eighteenth Century. 33

block entablatures, semicircular arches are carried over the aisles, and received on consoles on
the outer walls, and, b\- the intersection of these, pendentives are formed, carrying small shallow
domes over the galleries. The nave terminates eastwards in two quadrants of circles on each side,
and beyond is the altar recess, which has a semi-elliptical vault parallel to the nave vault. The
ceiling is richly panelled, and decorated with raised plaster work, consisting of panel mouldings,
relieved with a guilloche of simple yet bold design, and panels with centre flowers, paterae, angle
pieces, and other foliage surrounding clouds and cupids. The royal arms of the Stuarts, in
accordance with the then prevailing fashion, adorn one of the panels at the end of the ceiling near
the altar. The block entablature enrichments and the column capitals are finely modelled. This
effective plaster work was executed by G. .Arturi and .A. Baggutti, who also did the plaster work at
St Mary's-le-Strand and many other works in plaster for James Gibbs.

The ceiling depicted in Plate XXIII. shows a little over one quarter of a ceiling in Alilton
House, Edinburgh. This ceiling is in the style of Louis XV., and was executed b\- French
plasterers. In 1845 my father did some repairs to this ceiling, and judging from the tool marks
on the work, and the general absence of precision of balance in depth and distance of the rights
and lefts of the ornament, which is always, or nearly so, found in cast work, he was of opinion
that all the ornament was worked in situ by hand. Illustration No. 11 shows the elevation
with profile of the cornice. Milton House was erected about 1725 for Andrew Fletcher, a son
of " Fletcher of Salton." The house has recently been demolished, and a Board School erected on
the site. The example of a plaster ceiling in the classic style is depicted in Plate XXIV. This
shows a portion of the plan (a little over one-half) of the dining-room ceiling at Sir Mark Pleydell's
Mansion, Coleshill, Berkshire, erected about 1750, and designed by Inigo Jones. An elevation of
the cornice is shown at the bottom of the Plate ; this also shows section of the cornice and ceiling
panel mouldings.

The plan, with elevation and section, of the ceiling depicted on Plate XXV., is one in the
Queen's room in old Buckingham House (the site of Buckingham Palace). This beautiful ceiling
was designed by Robert Adam about 1760, the enrichments being modelled by Rose. Adam
created a style which still bears his name. The style affords but scant scope for the modeller's
talent. The enrichments are mostly a series of small repeated parts, consisting generally of wreaths,
or swags of husks, beads, festoons of leaves in ribbons, relieved at intervals with Etruscan vases.
Many of the designs have cartouches with figures in low relief, or with paintings by artists of note,
such as Kauffmann, Cipriani, and Zucchi. The style as a whole is chaste and graceful. Robert
Adam was born in 1728 at Kirkcaldy, in Fifeshire.

The brothers Adam (Robert and James) are credited with introducing the plan of building
several houses together, so as to represent when completed one building of imposing appearance
and dimensions. The introduction of the steel fire-grate, and the practice of plastering the
exteriors of brick houses, and composition enrichments for wood, iron, and plaster work, is also
attributed to them. Robert died in 1792, and was honoured with a tomb in Westminster Abbey. I
have given these details partly because the brothers Adam introduced into England stucco facades
and composition enrichments, and parti)' because of the recent revi\-al of their style which caused
a great amount of inquiries and comment in the trade.

An excellent example of Sir Christopher Wren's decorative plaster work is to be seen in
the office of the Xew Ri\er Company.

In 1750, Denstone, of Derbjshire, did some fine hand-wrought plaster work at Cambridge.

An interesting example of a plaster ceiling in the antique style is depicted in Plate XXVI.

34 Plastering — Plain and Decorative.

This shdu- a portion of the ceilinij in the Grecian Hall at Kcdleston, Derbj-shire, executed for
Lord Scarsdalc about 1770. The hall is 60 feet 6 inches by 30 feet 6 inches. The cornice is
omitted from this illustration. The ceiling is parti)- coved, as indicated b}- the open spaces at the
angles, which converge to the straight portion of the ceiling. The two oblong j^anels, with the
oval enrichments at the straight part of the ceiling, as shown in the illustration, art repeated twice
and a half to complete the length of the ceiling. This handsome ceiling was designed bj- G.
Richardson, and the Grecian trophies and the other ornaments were executed by Rose.

The dressing-room ceiling (Plate XXVII.) in Lord Montalt's mansion, Dublin, was executed
about 1770. The room is 24 feet long and 20 feet wide. The bas-relief in the centre panel, repre-
.scnting Hercules and Omphale, was executed by E. Robbins, and the other ornaments were
modelled b_v A. Collins. This elegant and chaste ceiling was designed bj- G. Richardson.

From 1750 to 17S0 A. Wilton did some fine plaster work at Cambridge, and in man)' mansions
in London and vicinit\\ Wilton was the father of Wilton the .sculptor, who originall)' was brought
up to his father's business, but after spending man)- )'ears in Rome he returned to London, and was
one of the founders of the Ro)-al Academy.

In 1783 Thomas and Charles Clark, two Irishmen, were employed by Sir William Chambers on
the fine plaster work at Somerset House. About the same time they also did some good work in
Dublin. W. Collins, who died about 1793, was also employed by Sir William Chambers at
Somerset House.

John I'apworth, an eminent stuccoist of London, who died in 1799, did the decorative plaster
work in the great Royal Academy Room at Somerset Hou.se, and, with his eldest son, also at the
rebuilding of the chapel of Greenwich Hospital, under James Stuart, the Athenian. The whole
of the work was done b\- hand /;/ situ. There is a curious anecdote concerning this building.
Young Papworth, some )-ears afterwards, was showing the place to a part)' of friends, and one of
the guides informed them that the plasterer who did the ceiling, when lying on his back on the
.scaffolding, tumbled off and was killed. Great was the astonishment of the guide when Papworth
said he was the workman. Papworth was the father of a long race of architects and writers
on art.

The examples of decorative plaster work mentioned in this chapter are some which I have
personally seen or which have been brought to m)- notice on account of their rarity or exceptional
artistic features. My readers will be aware that a great many further fine examples are to be
found within the United Kingdom.

The names of other modellers and plasterers are given in other parts of this work, not onl)-
as a tribute to their worth as men who gloried in their works, but also to encourage the rising
generation of plasterers to endeavour to get their naines inscribed in the plasterers' niche of P"ame.

Plati: III.

Siucco Ceiling and Wall Decoration, Palazzo d'Ai.brizzi, Venice, by A. Vittorio, 156c.

Plate IV.

Stucco Ceiiini; over Dock, axu Wall Decokaitox, I'alazzo d'Ai krizzi, Venice, bv A. \"irTORio, 1560.

p
■7:

Plate VII.

Portion of Plaster Ceiling, Losely House, near Guildford, 1562.

Plate VIII.

Portion of Plaster Ceiling, Cooper's House, Great Yarmouth, 1596.

Plate IX.

Portion of Plaster Ceiling, Peartref.s Hoise, Great Yarmouth, Sixteenth Century.

Plate X.

Scale o* f «rt

I'lASTER Ceiling, 4 South Quay, Great Yarmouth, Sixteenth Century.

Plate XI.

Portion of Plaster Ceiling, Bkamshili, IIoise, Hampshire, 1603.

Plate XII.

Portion of Plaster Ceiiinu, Aidi.ey End, i6io.

Plate XIII.

Fk;.' 2.

Fio.

Fig. 3.
Plaster Ceilint., State Bed-chamber, Boston House, 1623.

Plate XVII.

Stucco Ceiling, Holyrood Palace, Edinburgh, 1671.

73
3

■J

Plate XX.

^"^V

Section.

Portion of Ceiling, Qleen's Bed-chamber, Palace ok Versailles, Locis XV.

Plate XXI.

Portion of Ceiling, Salon des Medailles, Palace of Versailles, Louis W.

Plate XXII.

r^V^

Portion of Ceii.inc, Siudy of the Queen of Italy's Villa, Turin, Eightf.enth Century.

Plate XXIII.

Portion of Plaster Ceilinc, Milton House, Canonoate, Edinburgh, 1725-

Plate XXIV.

l/ij 4iT--f*rii' ir^ ^\ci

:v -»-.

WSAAA!A.1.A:A.:^

■-Kir-*rj5i -c '>ari;-t.ri^rjia»iaftsr5^v>^'?*3fH*-*-£

Portion of Ceii.im: and Cornice, Dinin(;-room, Coi.eshii.i., Berkshire, rv Imc.o Jones, 1750.

Plate XXV.

iTv:

t.:i^-i

Elevation with Section of Covkd Part ok Ceiling.

■f!'rp^m!m mMM?&m^m^s^ ^M mm Emsm immjtm:t ■■■v-wvw iw^-^' -i y n v >, r i .itjauu.ui.iijJLu.uij i n ' tufi i >> n

?S.va-jr-«^»]g»a;aa^^;V^iiJ.^.')tiHitWai»i<i «sy^^

.T 3ir!agi » ii < aou*L<j< .i. ii f. w .

ii:^^^i^-^?SD

17 M

mm II

I '^sig^ffe^T^iijft^:^^'^ ifrs^ ^ ;■

Fiuniimiiiii

IfBTWI!

'■ .-'■ -•'■ -/ -. •

■■■ ■

Ckilini;, ijuken's Room, Oi.i> Bi'ckingiiam IIoise, Lon'don, r.v U. Adam, 1760.

Plate XXVI.

Portion of Plaster Ceiling, Kedleston, Derbyshire, by G. Richardson, 1770-

Plate XXVII.

Plaster Ceiling, Lord Montalt's Mansion, Durlin, hy G. Richardson, 1770.

i
i

X
X

o
O

9 o

CHAPTER II.

MATERIALS.

Plaster : The Manufacture, Tests, Chemical Properties, Uses, Compressive and Adhesive
Strength, OF Plaster of Paris— Limes : Hydraulic, Lias, Chalk Limes, ^L•^xuFACTURE, Calcina-
tion, Slaking, and Tests — Mortar: Hardening of Mortar, :nL\gnesia in Mortar, Coarse
Stuff, Lime Putty, Setting Stuff, Effects of Salt, Sugar, and Frost on Mortar, Tests and
Adhesive Strength of Mortar — Hair : Ox Hair, Fibrous Substitutes for Hair— Sand : Pit,
River, and Sea Sands— Mastic : Scotch and London Mastics, ^L\STIC Mouldings, Hamelein's
Mastic, Mastic Cement— Stearate of Lime.

Plaster of Paris. — Gypsum, from which phister of Paris is made, is a sulphate of Hme, and is
so named from two Greek words — ge, the earth ; and epsun, to concoct, i.e., concocted in the
earth. In Ital)' it is known by the name oi gesso; in Scotland it is called stucco; in America it is
known as calcined plaster ; and in the English trade a.s plaster. The term "plaster" will henceforth
be used in this book. The writings of Theophrastus and other Greek authors prove that the use
of plaster was known to them. A stone, called by Theophrastus gypsos, chiefly obtained from
Syria, was used by the ancients for converting into plaster. Gj'psum is mentioned by Pliny as
having been used by the ancient artists, and Strabo states that the walls of Tyre were set in
gypsum. The Greeks distinguished two kinds — the pulverulent and the compact. The latter was
obtained in lumps, which were burnt in furnaces, and then reduced to plaster, which was used for
buildings and making casts.

Gypsum is found in most countries — Italy, Switzerland, France, Sicil)-, the United States, and
some of the South American States ; also in Newfoundland and Canada. The latter is said to be
the finest deposits in the world. It is found in this countrj' in the counties of Derbyshire, Cheshire,
Nottingham, Cumberland, and Westmoreland. The finest gypsum is called "alabaster," and is
soft, pure in colour, and fragile. This white translucent material is a compact mass of crj-stalline
grains, and is used for making small statuary, vases, and other ornaments. Gypsum is found in
immense quantities in the Tertiary strata of Montmartre, near Paris. This gypsum usually contains
lO per cent, of carbonate of calcium, not always in intimate union with the sulphate, but
interspersed in grains. This sulphate gives the Paris plaster some of its most useful properties.
Pantin, near Paris, has large beds of gypsum, one bed being horizontal and over 37 feet thick.

The term "Plaster of Paris" was mainly applied to it because gypsum is found in large
quantities in the Tertiary deposits of the Paris basin. Another reason is that lime and hair mortar
is seldom used in Paris for plaster work, plaster of Paris being used for most kinds of internal and
e.Kternal work. Plaster is known in the colour trade as terra alba. Plaster of Paris was known in
England by the same name as early as the beginning of the thirteenth centur\-. The gypsum,
in blocks, was brought from France, and burnt and ground here. It continued to be burnt and
ground by the users until the middle of the present century. The burning was done in small
ovens, and the grinding in a mill, sometimes worked by horse-power, or more often bj- hand.

-^' Plastering — Plain and Decorative

Messrs J. Ramaj^c & Son, of Mdinburgh, with whom I served a jjart of my apprenticeship, burnt
and ground their own plaster. I remember well that on more than one occasion I had to do a turn
at the handle of the grinding machine as a punishment for some boyish indiscretion.

Plaster is the most vigorous as it is the oldest vehicle for carrying down generation after
generation the masterpieces of art with which the golden age of sculpture enriched the human
race. I'or reproductive uses, plaster enables youth to contemplate antiquitj' in its noblest
achievements. To-day plaster is rc\okitionising industrial art for us, and in all probability for
those who are to come after us. Plaster, lowly and cheap, but docile and durable, is the connecting
agent with this greatest of men's endorsement in the past. Plaster thus emplojxd in duplicating
works of marble, pottery, and metal work, is to-day extending the finest industries, modern and
ancient. Plaster is one of the best known fire-resisting materials for building purposes. After the
conflagration at Paris, it was found that beams and columns of wood which had been plastered
were entirel)- protected froin fire. In cases where limestone walls had been ruined on the
outside b}' the flames passing through the window openings, the same walls internally e.scapcd
almost unscathed owing to their being protected with plaster. Plaster in some climates has great
lasting properties. The Egj'ptians co\ered their granite sometimes, and sandstone always, with
a thin coating of stucco. The Greeks coated even their marble temples with plaster, and the
plaster portions are now in better jjreservation than the unprotected masonrj-, particularl)- at
Agrigentum in Sicil)-.

M.-\NUFACTURE. — The gypsum is got by blasting, and by crowbars and picks. The only
preparation which it undergoes before calcining consists in chipping and cleaning the outer
portions if earthy, which would give the plaster a bad colour. The finest and whitest gypsum
is selected for fine plaster, the darker and coarser being used for coarse plaster. There are two
processes for manufacturing plaster in this couiitr_\-, viz., " boiled " and " baked."

BOILKI) Pl.V.STEK. — By the boiled process, the gypsum, after being quarried, is broken by
means of a pulveriser, and then carried up by an elevator into a hopper, from which it is conducted
down again by a spout to a pair of millstones, the feed being regulated by means of a small spindle
attached to the cross-bar of the stones, which in revolving are made to agitate the spout, and cause
the gypsum to fall in a regular stream between the stones. After grinding, the gypsum is again
elevated into hoppers, which supply a large open pan or boiler to a depth of about 3 inches.
The pan has large flues underneath it, heated by a furnace at one end. The gypsum is kept in
agitation on this boiler by means of a pair of rakes attached to a spindle, which revolves by
machinery. .Xfter it has been on the boiler for about an hour and a half, the powder becomes
agitated by means of the heat, and small volcanic-like eruptions take place, through the water of
hydration being driven off. At the expiration of about three hours, the powdered gypsum becomes
more dense and sand-like, lying heav)- on the scrapers or rakes. This is termed by the makers as
"just caught," and an experienced plaster boilcrman knows by the waj- the powder hangs when it
is ready. As soon as the latter is complete, a slide which forms one of the side plates of the boiler
is drawn, and the plaster is thrown off by the circular motion of the scraper. It is then left to cool,
and afterwards bagged up for commerce.

The waste of gypsum in evaporation and dust which takes place in the [process of boiling
is about 25 per cent. Boiled plaster is fine in texture, works verj- free, and when set is not liable to
warp. It is also generall)- more reliable than baked, from the fact that each molecule is properly
treated, and the material alike throughout. If the powdered gypsum is left too long on the boiler,
it is burned, and will not set for a considorable time, if at all. It is also very "chalky," and if it

Plaster Manufacture. n

is not boiled enough it is also weak, so that the greatest care and experience is necessary in the
boiling of plaster.

Baked Plaster. — For the baked process, several methods of heating the gypsum are
adopted. A flat kiln or oven, so constructed that the fuel is never in contact with the stone, is
generall)- used. The kiln is raised to a low red heat, when the firing is discontinued, and the kiln
charged with lumps of gypsum. The heat is then gradually increased. After about sixteen hours
the gypsum has lost its water of hydration, and after grinding becomes plaster. The kiln is
sometimes worked continuously, and is heated by flues carried round the kiln. \\'hen this method
is adopted, it is necessary to observe that the temperature does not rise too high, and that the
plaster is drawn as soon as the water has been evaporated. Great experience is required in
carrying out this process (which is simply one of dehydration) successfully, for although, when the
temperature is kept within proper limits, the plaster possesses the power of reabsorbing water with
avidity, this power is diminished if the gj'psum be overheated. When subjected to a red heat,
the gypsum increases in density, and if this temperature be continued it gradually assumes the
character of natural anhydrite, which has totally different properties to those of plaster. It is safer
not to drive off the whole oi the water rather than risk exposing the gypsum to too high a
temperature, as the retention of a small portion of moisture does not prevent the plaster from
reabsorbing the water that has been driven off. The time required for burning depends greatly
upon the quantity and hardness of the stone in the kiln. It is considered to be sufficiently baked
when the plaster is of an oily nature, and adheres to the workman's fingers.

Quick axd Slow Setting Plaster. — M. Landrin, in giving the results of his long
continued studies relative to the different qualities of gypsum, states that the more or less rapid
setting of plaster is due to the mode in which it is burned. Its properties are very different when
prepared in lumps or in powder. The former when mi.xed in its own weight of water sets
in five minutes, while the latter under similar conditions takes fifteen minutes. The reason
probably is that plaster in powder is more uniformly burned than when it is in lumps, which
tends to prove this fact, that when the latter is exposed longer than usual to the action of heat
it sets more slowlj-. Gypsum prepared at a high temperature loses more and more of its affinity
for water, retaining, however, its propert\- of absorbing its water of cr\'stallisation. Plaster heated
to redness and mixed in the ordinary manner will do longer set ; but if, instead of applying a large
quantity of water, the smallest possible portion is used (say one-third of its weight), it will set
in ten or twelve hours, and becomes extremely hard. To prepare good plaster, it should not be
burned too quick to drive off all its moisture, and for its molecules to lose a part of their affinity
for the water. If the plaster is exposed to heat until it has only lost 7 or 8 per cent, of its moisture
it is useless, as it sets almost immediately. If, however, the burning is again resumed, the substance
soon loses its moisture, and if then exposed to the air it very rapidly retakes its water of
crystallisation, and absorption continues more slowly. It then sets slowly, but attains great
hardness.

Testing. — The quality of plaster may be tested by simply squeezing it with the hand. If it
cohere slightly, and keeps in position after the hand has been gentlj- opened, it is good ; but if
it falls to pieces immediately, it has been injured by damp. Although plaster docs not chemically
combine with more than one-fourth of its weight of water, _\et it is capable of forming a much
larger quantity into a solid mass, the particles of plaster being converted into a network of crystals,
mechanically enclosing the remainder of the water. Sulphate of lime (plaster) is soluble in water
to the extent of i part in about 450, the solubility being but little influenced by temperature.

38 Plastering — Plai)t ami Decorative.

It is on account of this solubility in water that cements which have to a large extent plaster for
their basis are incapable in this raw state of bearing exposure to the weather. The setting of plaster
is due to hydration, or its having but little water to take up to resume a state of consolidation.
Plaster is used with hydraulic limes to stop the slaking, and convert the lime into cement. These
are then called "selenitic."

In lOO parts of g)-psum there are 46 acid, lime 32, and water 22 parts. Good plaster should
not begin to set too soon, and it should remain for a considerable time in a creamy state. When
once set it should be very hard. I'lastcr should set slowly, as it gives more time for manipulation,
but principall}' because one which sets quickly and swells, never becomes so hard as slow-setting
material. The quality of plaster cannot be determined by its colour, the colour being regulated
by that of the gypsum ; but all things being equal, the wliitcst and hardest generally yields the
best plaster. But as the exception proves the rule, it may be mentioned that the Cumberland
plasters (such as Howe's) are of a delicate pink tint, and of a very fine grain, and exceedingly strong
when gauged. This pink plaster is much appreciated by many plasterers for making originals, as
owing to its fineness and density it is very suitable for cleaning or chasing up models taken from
the clay, and also for durable moulding pieces. One of the whitest plasters in England, which is
al.so very close in texture, is that manufactured by Cafferata. For cast work the colour of ])lastcr
is of small moment, because the cast work is sooner or later coloured with paint, and moreover,
unfortunately daubed over with distemper, or, worse still, w ith whitewash. Coarse plasters are
darker in colour than fine. Coarse plasters of a sandy nature, and which rapidly sink to the bottom
when put in water, contain too much silica, or improperly burnt g)-psum, or are derived from a
bastr.rd gypsum, and are generally of a weak nature.

Compressive and Adhesive Strength. — The compressive resistance of properly baked
plaster is about 120 lbs. to the square inch when gauged with neat water, and 160 lbs. when gauged
with lime water ; thus showing that lime water hardens and improves the affinity of plaster. The
adherence of plaster to itself is greater than to stone or brick. The adhesion to iron is from 24 to
37 lbs. the square inch.

Fken'CH Plaster. — A considerable quantity of I-"rench plaster was formerly used in London ;
but owing to the English plaster being now more uniform in qualitj- and cheaper in price, the use of
the French material is somewhat limited. A considerable quantity of gypsum is imported to
Bristol from France. The stone is manufactured at Bristol, and has all the superior qualities of
French plaster. This is generally known as " Bristol plaster." Benvenuto Cellini preferred the
French plaster to that of Italy, his own country. In Paris various kinds of gy[jsum mortars are in
general use, raw gypsum and other materials being often intermixed. They also contain free
carbonate of lime, according to the degree of heat to which the raw stone has been subjected. The
Hotel de Platres, in Paris, affords a good illustration of the constructive uses to which plaster can
be put, some of the blocks being about a hundred years old.

Limes. — Lime is one of the most important materials in the building trades. Limestone is
the general term by which all rocks are roughly classified which have carbonate of lime for their
basis. They are obtained from many geological formations, varying in quality and chemical
properties. The Carboniferous consists of nearly pure carbonate of lime. In the limestone of the
Lias carbonate of lime is as.sociated with silica and alumina (common clay) in proportions \arying
from 10 to 20 per cent. The best kinds are obtained from Aberthaw, Rugby, Barrow, and (jther
districts in England ; Arden, Fife.shire, and other places in Scotland ; and Calp and Larne in
Ireland. Carbonate of lime is found in a state of chemical purity in rhombohedral crystals as

Limes. 39

Iceland spar. It is also found in six-sided prisms, known to mineralogists as arragonite. Its purest
form as a rock is that of white marble. Coloured marbles contain iron, manganese, &c.

The Lias strata consist of a thin layer of hard limestone separated by another of a more
argillaceous character, or shale, containing various proportions of carbonate of lime. The Lias
districts extend from L}me Regis to the north-east of Yorkshire ; the limestone in the counties of
Warwick, Dorset, and Leicester. In the chalk districts of Kent and Surrey there are in the upper
chalk a soft kind of comparatively pure carbonate of lime, and in the grey chalk lying below it
there is a carbonate of lime of a harder description, having a small proportion of argillaceous
matter.

Hydraulic Limes. — Hydraulic limes are those which have the property of setting under
water or in damp places, where they increase in hardness and insolubility. The blue Lias lime
formation is that from which hydraulic lime is principall\- obtained in England, and it is found
over a wide area — at Aberthaw, and at Rugb\-, where it is also manufactured into Portland cement.
This lime, while it has excellent hydraulic properties, can hardly be classed as a cement. The
stones which produce these limes contain carbonate of lime, clay, and carbonate of magnesia. The
clay plays an important part in giving hydraulicitj- to the lime, consequently this power is greater
in proportion to the amount of cla)- contained in the lime. The proportion of clay \-aries from
lo to 30 per cent. When lime contains clay it is not so easily slaked as pure lime, and does not
expand so much in doing so, and therefore does not shrink so much in setting.

Lias lime (called blue Lias from the colour of the stone from which it is produced) is very
variable in quality and is generally of a feeble nature, but is sometimes of an hydraulic nature.
M. Vicat divides them into three classes : feebly hydraulic, ordinary h\-draulic, and eminently
hydraulic. "Those belonging to the first class contain from 5 to 12 per cent, of clay. The slaking
action is accompanied by cracking and heat. They also e.xpand considerably, and greatly resemble
the fat limes during this process. They are generally of a buff colour." Those of the second class
contain from 15 to 20 per cent, of clay. "They slake very sluggishly in an hour or so without
much cracking or heat, and expand very little. They set firmlj' in a week. The eminent!}-
h}-draulic limes contain from 20 to 30 per cent, of clay, are very difficult to slake, and only do so
after a long time. Very frequcnti}- thej- do not slake at all, being reduced to a powder by grinding.
The\- set firmly in a few hours, and are very hard in a month."

A natural h}-draulic lime, known as " Arden lime," is found in the \\'est of Scotland. This
lime is obtained from what appears to be a sedimentary limestone that has been formed b\- being
deposited from water which held it in solution. It is very fine grained, and contains almost no
fossils, and scarcely the trace of a shell is to be seen, except at the top and bottoms of the divisions,
which are four in number, and in all from 9 to 12 feet thick. When first worked, the stone was
slaked in hot kilns, but now this is effected by grinding. According to the " M'Ara" process, the
"lime shells" from the kiln are ground in the same way as the clinker of Portland cement. Beginning
with a stone-breaker, the lime passes from this to a pair of chilled crushing rollers, and finallj- to
the millstones, after which the powder is carried by screw-conveyor and elevator to a rotary .screen,
12 feet b>- 4 feet, covered with wire-cloth, which retains and returns to the millstones any residue
in excess of the required fineness. Sifting is a ver\- imix)rtant factor in the proce.s.s, as it is .scarcely
possible to have the millstones so perfect that the}- will not pass a few large particles.

The residue of imperfectly ground lime will doubtless slake when mixed with water, but at
long or uncertain periods, so that it is obvious that fine grinding is a necessity, and the setting
properties are not full}- and safely developed unless the whole is finch- pulverised. With regard to

Plastcritig — Plain and Decorative.

fine grinding', the expense to the manufacturer is increased in proportion to the fineness, so much
.so, that to reduce the lime down to a residue of 15 per cent., instead of 35 per cent., will quite
double the cost of grinding. Against this, however, a reliable natural cement is obtained. On the
other hand, if coarsely ground, the covering capacitj', and subsequent strength of the mortar or
concrete, is very much less. This hydraulic lime, tested on the same lines as for Portland cement,
has a tensile strength per square inch at 7 days from So lbs. to 100 lbs ; i month, 150 lbs. to
200 lbs. ; 6 months, 350 lbs. to 400 lbs. ; and 3 years, 600 to 700 lbs.

The setting and hardening are mainly due to crystallisation, caused by the action of water
on the silicate of lime, as shown hereafter.

The following is an analysis of hydraulic limes : —

Table I. — Analysis of Hvdraulic Limes.

Lime.

Silica.

Alumina.

Oxide

of
Iron.

.Magnesia.

Water,
Carbonic
Acid, &c.

Authority.

Aberthaw Blue Lias - - - -

78.45

9.35

6.25

trace

...

5-70

H. Faija, 1885.

Barnstonc „ ....

59.61

20.61

6.98

4.01

2.25

6.54

J. B. Dyer, F.C.S.

Warmsworth Cliff(Yorks) Magnesian

58.4

0.5/^

...

1.4

38.6

I.l

F. Hudson.

Chalk Li.ME. — Chalk lime is a term u.sed principal!}- in London for fat lime. l""at lime is
produced from the purest of the limestones, which are nearly pure carbonate of lime. It is also
known as " pure lime " and " rich lime." As it has little or no setting power, and is easily dissolved
in water, it is unfit for any purpose where strength is required, or in situations exposed to the
weather.

The general practice is for lime producers to .show their lime as rich as possible by analysis,
and for users to prefer a rich lime, for the reason that it makes a more plastic and better working
mortar with the usual quantity of sand. Now, it has been proved by experiments, many and
varied, and extending over a long jjcriod, b}- the most eminent authorities, French, German, and
English, — most prominent amongst them Smcaton, — that this preference should exactly be re\ersed,
and that the poorer common limes will make the best mortar, and will, in a comparatively short
time, show some slight .setting power, whereas the very rich limes never take band, except in so
far as the}- return to their original condition of carbonate b\' the reabsorption of carbonic acid from
the atmosphere, and by the slow evaporation of the water of mixture. If it does not evaporate,
the mortar remains always soft. If it evaporates too quickly, the mortar falls to powder, a result
which must be in every one's experience who has witnessed the taking down of old buildings, and
the clouds of dust created by the removal of every stone.

Some of the stones from which fat lime is produced contain a proportion of .sand as an
impurit)'. They therefore yield an inferior substance. This, though cheaper, is not so economical
as pure lime, as it does not increase its volume so much when slaked. The pure or fat lime should
only be used for plastering, as it is easily slaked, and therefore not so liable to blister as most
hydraulic limes. It expands to double its bulk when slaked, and can be left and reworked again
and again without injuring it.

Amongst the great variety of Scotch limes, those of the Murlet and Campsie series have a

Calcining Lime. 41

reputation which has been handed down for generations. The analysis of the lime from the mines
of the Hurlet and Campsie Akim Company gives the following proportions :— Carbonate of lime,
91.40 ; carbonate of magnesia, 3.40 ; carbonate of iron, 2.07 ; bi-sulphide of iron, .41 ; alumina, .60 ;
silica, i.OO ; phosphoric acid, .10 ; coaly matter, .80 ; water, .10.

Irish rich lime, as used in the West of Scotland for the finishing coat of plaster work, is slaked
by immersion, as the Romans are said to have prepared their limes. This "lime putty," prepared by
immersion for a longer or shorter period — seldom less than three weeks — before being used, is laid
on in a very thin coat, and gives a hard skin to the surface. This hardness is largely, if not wholly,
due to the fact that the lime is laid on in a thin layer on the floating coat that has already absorbed
carbonic acid from the air. This thin layer becomes harder than the main body of the plaster.

The whole process of preparing lime and laying it on the walls in thin coats, with a con-
siderable space of time between the coatings, is conducive to the ultimate hardness of the whole.
The lime is first slaked, and then made into coarse stuff and setting stuff, all this time being
exposed to the carbonic acid of the atmosphere. Again, each coat is long exposed to the same
influence before being covered with the next, altogether in marked contrast to the system of using
the mortar in building.

Calcination. — The process of " lime-burning " is carried out in several different ways. But
whether the operation be carried out in the simplest manner, or in kilns constructed on the most
scientific principles, it will still depend (both as regards the quality and quantity of lime
produced; upon the kilnsman, as it is onl\- by constant observation from day to day that the man
becomes capable of judging whether the proper temperature has been reached, or that a correct
opinion can be formed as to the effects produced by the various disturbing causes which exert an
important influence upon the working of a kiln, such as its size, shape, the qualit\' of the fuel, and
the state of the atmosphere. The kilns vary in size and shape in different districts, though they
are generally inverted cones or ellipsoids, into which layers of limestone and fuel are alternately
thrown. When worked continuously as running kilns, the lime is periodically withdrawn from
below, fresh quantities of fuel and stone being filled in at the top. When lime has not been
properly calcined, or " dead burnt," it will not slake with water. This may arise from two causes
— from insufficient burning, when the limestone, instead of being entirely caustified, has only been
changed into a basic carbonate, consisting of two equivalents of lime and one of carbonic acid,
one-half only of its carbonic acid having been expelled. This basic carbonate, on the addition
of water, instead of forming a hydrate of lime, and being converted into a fine and impalpable
powder, attended with the production of a large amount of heat, is changed, with little elevation
of temperature, into a mixture of hydrate and carbonate. In the case of hydraulic limes which
contain a considerable amount of silica, this "dead burning " maj- arise from the limestone having
been subjected to a too high temperature, whereby a partial fusion of the silicate of lime formed
has been produced, giving an impervious coating to the inner portions of the stone, retarding
the further evolution of the carbonic acid. On this account the eminently hydraulic limes require
to be carefulK- calcined at as low a temperature as practicable ; and hence it is not infrequentl\-
found that Lias lime has been imperfectly calcined. Pure limes, if subjected to an e.xcessive
temperature, exhibit somewhat less tendency to combine with water than is the case with lime
properly calcined. Caustic lime unites with water with great energy, so much so as to evolve a
very considerable amount of heat. When water is poured upon a piece of well-burnt lime heat
is rapidly generated, and the lime breaks up with a hissing, crackling noise, the whole mass being
converted in a short time into a soft, impalpable powder, known as " slaked lime."

42 Plastering — Plain ami Decorative.

Slakinc. — Chemically speaking, slaked lime is liydrate of lime — that is, lime chemically
combined with a definite amount of water. In the process termed "slaking," one equivalent or
combining proportion of lime unites with one equivalent of water, or in actual weight 28 lbs. of
lime combines with 91 lbs. of water (being nearly in the proportion of three to one) to form 37 lbs.
of solid hjdratc of lime. The water loses its liquiil condition, and it is to this solidification of
water that the heat developed during the process of slaking is partly due. In England the burnt
lime, before it is slaked, is generally called " lump lime," in Scotland it is called " shells."

Slaking is a most important part in the process of making coarse stuff and putt)' lime.
Unless the slaking is carefully and thoroughly done, the resultant materials are liable to "blister"
or " blow," owing to small particles still remaining in a caustic state. Blisters may not show
until a considerable time has elapsed. There are three methods of slaking "lump lime" — the
first by immersion ; the second by sprinkling with water ; and the third by allowing the lime to
slake by absorbing the moisture of the atmosphere. Rich limes are capable of being slaked by
immersion, and kept in a plastic state. They gain in strength b\' being kept under cover or
water. I'liny states that the Romans had such great faith in this method that the ancient laws
forbade the use of lime unless it had been kept for three years. All rich limes may be slaked
by mixing with a sufficient quantity of water, so as to reduce the whole to a thick paste. Lump
lime should first be broken into small pieces, placed in layers of about 6 inches thick, and
uniforml)- sprinkled with water through a pipe having a rose on one end, or by means of a large
watering-can having also a rose, and covered quickly with .sand. It should be left in this
state for at least twenty-four hours before being turned over and passed through a riddle. The
layer of sand retains the heat developed, and enables the process of slaking to be carried out
slowly throughout the ma.ss. Any un.slaked lumps may be put into the middle of the next
heap to be slaked. The quantity of water should be properly regulated, as if over-watered a
useless paste is formed. If a sufficient quantity is not supplied, a dangerous powdering lime
is produced. Slaking by sprinkling and covering the lime lumps is frequently done in a ver>'
imperfect and partial manner, and portions of the lime continue to slake long after the mortar has
been used. Special care must be exercised, and sufficient time must be allowed for the lime to
slake when this method is emploj-ed.

Different qualities of lime require variable amounts of water ; but the medium quantity is
about a gallon and a half to ever)' bushel of lime. No water should be added or the mass
disturbed after slaking has begun. In most parts of England the lime for making coarse stuff is
generally slaked by immersion, and is run into a pit, the sides of which are usually made up with
boards, brick work, or .sand, the lime being put into a large tub containing water. When the
lime is slaked, it is lifted out by means of a pail, and poured through a coar.se sieve. It is
sometimes made in a large oblong box, having a movable or sliding grating at one end to allow
the lime to run out, and also to prevent the sediment from passing through.

In preparing lime for plaster work, the general practice in the North of Enghuul is to slake
it for three weeks before using. Not only so, but a particular cool lime is selected, for the reason
that it is not liable to blister and deface the internal walls when finished. Now, while all this
precaution is taken in regard to plastering, in making mortar for building the lime is slaked and
made up at once, and it is frequently used within a day or two. But this is not all. Limes which
are unsuitable for plaster work, known as hot limes, and which, when plasterers are obliged to use,
must be slaked for a period of^not three weeks, but more— nearly three months before using, and
are then not quite safe from blistering, are the limes mostly used for building purposes. It will

Mortars. 43

at once be seen that when mortars of these h'mes are used immediately, the unslaked particles go
on slaking for a long time, drying up the moisture, and leaving only a friable dust in the joints.
This should help in understanding the old Roman law which enacted that lime should be slaked
for three years before using. If three years should seem to us an absurd time, yet it may be justlj-
said that at least three months are required to slake completely, and to develop fully the qualities
of many of the common limes in everyday use. Major-General Gillmore, an eminent American
specialist, and a recent writer on the subject of Limes and Cement, mentions that in the South
of Europe it is the custom to slake the lime the season before it is to be used.

Mortar. — This is a term used for various admixtures of lime or cement, with or without
sand. For plaster work it is usually composed of slaked lime, mixed with sand and hair, and is
termed "coarse stuff," and sometimes "lime and hair," also "lime." In Scotland the coarse stuff
is generally obtained by slaking the lump lime (locally termed shells) with a combination of water
sprinkling and absorption. The lime is placed in a ring of sand, in the proportion of one of lime
to three of sand, and water is then thrown on in sufficient quantities to slake the greater portion.
The whole is then covered up with the sand, and allowed to stand for a day ; then turned over,
and allowed to stand for another day ; afterwards it is put through a riddle to free it from lumps,
and allowed to stand for six weeks (sometimes more) to further slake b\- absorption. It is next
" soured " — that is, mixed with hair ready for use. Sometimes when soured the stuff is made up
in a large heap, and worked up again as required for use. This method makes a sound
reliable mortar. In some parts lime slaked as above is mixed with an equal part of run lime.
This latter method makes the coarse stuff " fatter," and works freer. All slaked limes have a
greater affinity for water than the mechanically ground limes.

Grinding is another process for making mortar or " lime," and if made with any kind of
limestone is beneficial. It thoroughly mi.xes the material, increases the adhesion, adds to the
density, and prevents blistering. When there is a mortar-mill, either ground or lump lime
can be used, and the coarse stuff maj' be made in the proportion of i part lime and 3
parts sand. The lime should be left in the mill until thoroughly reduced and incorporated,
but excessive grinding is detrimental. The process should not be continued more than thirty
minutes. Both material and strength is economised if lump lime is slaked before being put
in the mill.

When a mortar-mill is used for grinding the lime, the sand may be partl\- or wholly dispensed
with, and excellent results are obtained by using old broken bricks (clean and well burnt), stone
chippings, furnace cinders (free from coal), or slag. It is most essential in all cases that the
materials used should be perfectly clean. It should be borne in mind that a complete incorpora-
tion of the ingredients is essential in the slaking and mixing for coarse stuff, whether done b)- hand
or machine. The sand or other material used can be tested by washing a portion in a basin of
clean water, then sifting through a fine sieve. If there is an undue residue of clay, fine dust, or
mud in the water or sieve, the whole of the aggregate should be washed or rejected. Lias lime
should be mixed dry with sand, and damped down for seven or ten days to ensure slaking. It
should not be used fresh for floating or rendering. Pure or rich limes are not so well adapted for
outside work, or places exposed to the action of damp, as hydraulic limes. Mortar should be well
tempered before using. Pliny states that it was an ancient practice to beat the mortar for a long
time with a heavy pestle just before being used, the effect of which would be not only more
thoroughly to mix the materials, but to take from the outside of the sand the compound of lime
and silica (if such had been formed during the period of seasoning), and by incorporating it with

flasfcyiiig — Plain and Decorative.

the mass, dispose it the more rapidlj' to consolidate. Smcaton found that well-beaten mortar set
sooner and became harder than mortar made in the usual wu)-. Mortar made from hydraulic
limes should be mixed as rapidly as is compatible with the thorough incorjioration of the
materials, and used as soon as practicable after mixing, because if put aside for any length of
time its setting properties will deteriorate.

Pure limes may be rendered hydraulic by mixing them with calcareous clays or shales, which
have been so altered by the agencj- of heat that the silica they contain has to some extent
assumed the nature of soluble silica. In good coarse stuff each granule of sand is coated over
with the lime-paste so as to fill the interstices ; the lime-paste is to hold the granular substances
in a concrete form. If too much lime-paste is present, it is called " too fat" ; if the lime-paste is
deficient, it is " too lean " or " poor." This can be tested by taking uj) a portion on a trowel ; the
" fat" will cling to the trowel, while the " lean " will run off like wet sand. The coarse stuff can
be tested by making briquettes, and slowly drying ; the good will stand a great pressure, whereas
the bad will not — in some cases falling to pieces. Some coarse stuff will appear " fat " on the
trowel, but it may be the fatness of mud, not the fatness of lime, because sometimes sand is
adulterated with fine-screened earth. When this stuff is made in the form of briquettes and dried,
it will be extremely friable, and easy to crush ; or if put into water until soft, the earthy matter
can be seen. Fine-screened earth, when dr\- and in bulk, docs not seem an objectionable
material ; but in a wet state it is dirt or mud, and should be at once sent off the works. All
limes increase in strength by the addition of sand, being the reverse of Portland cement, which
is weakened by this addition. Mr Read made four samples of mortar with the proportions of
ground lime and sand as follows: — "Ground lime mixed with 4, 6, 8, and 10 parts of clean
washed sand to i part of ground lime respectively. All set and went hard. One of each was
placed in water ; that made with 4 parts of sand expanded and went to pieces ; those with 6, 8,
and 10 parts of sand remained whole, and continued to get harder." The addition of a small
proportion of brick dust to mortar will harden and prevent the disintegration of mortar. The
proportions are i part of brick dust, 2 parts of sand, and i part of lime, mixed dr\-, and tempered
in the usual way.

Adhe.sive Strength. — The adhesive strength of mortar varies according to the amount of
sand used. The more sand used in the mortar, the less its adhesion. The following table shows
the force required to tear apart bricks bedded in mortar made with the usual proportions of sand at
the end of twenty-eight days : —

Taule II. — Adhesive Strengths of Limes and Cement.s.

White Chalk Lime and Sand

(I to 3)

4J lbs. per square inch.

Barrow Lias „ „

9 »

'» )> " )}

(I to 4)

6| ,

Portland Cement ,,

(I to 4)

23 ,.

*) ) 1

(I to 6)

15* >.

The old mortar which was held in such high esteem by the Romans is said to have
consisted of lime mixed with puzzolana or trass. Trass is a material similar in its nature to
puzzolana, obtained from extinct volcanoes in the valleys of the Rhine, also in Holland, and is

The Hardening of Mortar. 45

largely employed in engineering works. The name " trass " is derived from a Dutch word meaning a
binding substance. Much has been written and said about the ancient and the old Roman mortars,
but it may be safely said that, from the year one up to the present time, no cement or mortar has
the strength, or could excel, or stand our variable climate as well as Portland cement. The
primary cause of the premature decay which takes place in stuccos and cements, when used
externally as a coating to walls, is the presence of muddy earth and decayed animal and vegetable
matter in the sand used in the lime and cement. To this may be added the frequent impurities in
the limes and cement themselves. The impurities in the sand may be eradicated by thorough
washing, and the lime should be carefully selected, prepared, and manipulated. John Smeaton
used a mortar made of blue Lias from Aberthavv, and of puzzolana brought from Civita Vecchia,
near Rome, in the construction of the Eddystone Lighthouse. If it were to be built at the present
time, the cementing material would certainly be Portland cement. Having now briefly reviewed
the principal parts and processes of mortar, the practical conclusions to be drawn are, that the
quality of the lime is of as great importance as the quantity, and thorough slaking is imperative ;
that the proportions of sand may vary considerably, and that it should be coarse and irregular in
size, and of a clean and hard nature.

The Hardening of Mort.\r. — According to the results obtained from tests and e.xperience,
the hardening of mortar is due to several causes acting collectively. These causes appear to be
absorption of carbonic acid from the atmosphere, and the combination of part of the water with the
lime which act upon the sand, dissolve and unite with some of the silica of which the sand is
composed, thus forming a calcium silicate (silicate of lime). Some authorities state that the silicate
of lime is formed by the reaction of lime and silicate of mortar, and to this is due the hardness of
old mortar. In mortar made from pure lime, the initial setting is due to the evaporation of the water,
and to the production of minute crystals of hydrate of lime, which slowly absorbs carbonic gas from
the air, the rapidity of this absorption necessarily decreasing in proportion to the difficulties presented
to the free access of air. The setting and hardening of hydraulic limes are due mainly to crystal-
lisation brought about by the action of water on the silicate of lime, and not by mere absorption of
carbonic gas from the atmosphere, as is the case in fat limes.

The Romans were convinced that it was owing to prolonged and thorough slaking that
their works became so hard, and were not defaced by cracks. Alberti mentions that he once
discovered in an old trough some lime which had been left there five hundred years, as he was led
to believe by many indications around it, and that the lime was as soft and as fit to be used as if it
had been recently made. Common mortar made of rich lime hardens very slowlj-, and only b\- the
evaporation of the water of the mixture, and by the absorption of carbonic acid from the
atmosphere, with which it forms a cry.stalline carbonate of lime; This process, however, is so slow,
that it gave rise to the French proverb (quoted by Pasley) that " Lime at a hundred years old is still
a baby" ; and there is a similar ]jroverb among Scotch masons, ''When a hundred j-ears are past
and gane, then gude mortar turns into stane." Mortar from the interior of the Pyramids, where it
has been e.xposed to the action of the air, still contains free lime although it is five thousand }-ears
old. It has been ascertained that in rich lime mortars the carbonic acid penetrates about one-tenth
of an inch into the joint in the first year, forming a skin or film which opposes the further absorption
of carbonic acid, e.Kcept at a decreasing ratio, so that the lime remains soft for an indefinite period.

In illustration of this several cases have been cited, amongst others one by General Treus.sart,
who in the year 1822 had occasion to remove one of the bastions erected by Vauban in 1666. After
these 156 years the lime in the interior was found to be quite soft. Dr John, of Berlin, mentions

P/dsfcn'/zp- — P/ain and Decorative.

that in removing a jjillar t)f y feet diameter in the Church of St Peter. Berlin, eighty years after
erection, the mortar was found to be quite soft in the interior.

General Fasley mentions several instances at Do\er Harbour, and at Chatham dockjard, the
latter in particular, when part of the old wharf wall was pulled down in the winter of 1834. The
workmen were obliged to blast the brickwork fronting the river, which had been built with Roman
cement, but the backing, done with common lime mortar, was in a state of pulp ; the lime used had
been i)rcpared from pure limestone or chalk. But it is not necessary to go so far back for knowledge
of the absence of the setting quality in the rich limes, as there have been frequent experiences of it
in the present age. While these remarks are true of the richer limes, man>- of our limes are
comparatively poor in carbonate, and associated with silica, alumina, magnesia, and oxide of iron,
which may either be partiallj- combined in the natural state, or enter into combination with the
lime during the jsrocess of calcination, and these limes might be termed slightij' h>-draulic.

M. Landrin, who submitted to the French Academy the results of some experiments on the
hydraulicity and hardening of cements and limes, came to the conclusion that (i) silicates of lime
raised to high temperature set with difficulty, and in any case do not harden in water; (2) for the
calcination of cements to exert a maximum influence on the setting, in connection with water of
the compound obtained, the process must be carried sufficiently far for the limes to act on the silica
so as to transform it into hydraulic, and not into fused silica ; and (3) carbonic acid is an indis-
pensable factor in the setting of siliceous cements, inasmuch as it is this substance which ultimatel}-
brings about their hardening. The comparative strengths of various mortars are shown in the
following table : —

Comparative Strength of Grey Lime

Table III.

and Portland Cement Mortar, also I'ortland Cement Mortar with the addition
of Lime and Mortar.— Redcr.WE,

No.

T»ts.

Proportions.

Breaking

Strain on s.23

square inch

in lbs.

Breaking

Weight per

square inch

in lbs.

Ratio as
compared
with Lime

Mortar.

Ratio as

compared

with Cement

.Morlar.

RE.MARKS.

Sand.

Cement.

Lime.

Water.

3.00

...

1. 00

1-33

61.06

27-13

...

Three samples.

2.00

1. 00

1-33

106.07

47.09

Grey lime.

3 27

2.00

...

1. 00

'•33

82.00

36.44

... j

Water includes that required
for slaking lime.

' '5

6.00

1. 00

...

1.25

233-53

'03.79

2. Si to I

8.00

1. 00

...

1.66

1 54.80

68.80

1.86 to I

Cement taken from bulk in
store.

10.00

1. 00

...

2.00

112.88

50.16

1.36 to I

1 70

6.00

1. 00

0.50

i.So

165.31

73-47

2.00 to I

0.70 to 1 1

8.00

1. 00

0.66

2.00

132.62

5894

1.60 to I

0.S5 to I ,

Water includes that required
for slaking lime.

10.00

1. 00 0.83
Loain.

2.50

95-2-

42.34

1.14 to I

0.84 to I ;

6.00

1. 00 0.50

1. 00

136.80

60.80

1.64 to I

0.58 to 1

8.00

\
1. 00 0.66

'•33

86.48

38.43

1.04 to I

0.55 to I

Yellow loam, fresh dug, and
rather damp.

10.00

1. 00 0.S3

2.00

64.50

2S.66

0.77 to I

0.57 to 1

Magnesia in Mortars. 47

Magnesia in Mortars. — Magnesia plays an important part in the " setting " of hydraulic
h'mes as well as in Portland cement. Yicat, after many experiments, was led to recommend
magnesia as a suitable ingredient of mortars to be immersed in the sea, stating that if it could be
obtained at a cost that would admit its application to such purposes, the problem of making concrete
unalterable by sea-water would be solved. General Gillmore, speaking of the American lime and
cement deposits, says : " Magnesia plaj-s an important part in the ' .setting ' of mortars, derived from
the argillo-magnesian limestones such as those which furnish the Rosendale cements. The magnesia,
like the lime, appears in the form of a carbonate. During calcination, the carbonic acid is driven off,
leaving protoxide of magnesia, which comports itself like lime in the presence of silica and alumina,
b>- forming silicate of magnesia and aluminate of magnesia. These compounds become hydrated
in the presence of water, and are pronounced by both Vicat and Chatoney to furnish gangues, which
resist the dissolving action of sea-water better than the silicate and aluminate of lime. This
statement is doubtless correct, for we know that all of these compounds, whether in air or water,
absorb carbonic acid, and pass to the condition of subcarbonates, and that the carbonate of lime is
more soluble in water holding carbonic acid, and certain organic acids of the soil in solution, than
the carbonate of magnesia. At all events, whatever may be the cause of the superiority, it is pretty
well established by experience that the cements derived from argillo-magnesian limestones furnish
a durable cement for construction in the sea."

In Marshal Vaillant's report to the French Academy of Sciences, from the Commission to
which Chatoney and Ri\ot's paper was referred in 1856, this superiorit}- of the magnesian hydrates
is distinctly asserted. A few years ago the French Government Office of Civil Engineers made a
series of comparative tests on three samples each of French, English, and German cement, in which
the results are given in favour of the German cement, which contained magnesia to the extent of
2.4 per cent., against 0.26 in the English and 0.32 in the French, and summed up thus : " A great
value is to be placed on the presence of magnesia, and the excellence of the German cement is
partly due to the higher percentage of magnesia contained in it." Gillmore further says that
magnesian limestone furnishes nearly all the hydraulic cement manufactured in the western part of
the State of New York. At East Vienna it has been used for cement, and at Akron, Erie Co.,
X.Y., a manufactory of some extent is in operation. Vicat says : " Having analysed several old
mortars, with the view of discovering, if possible, to what their superior durability might be
attributed, I found, in some excellent specimens of very old mortar, magnesia to exist in consider-
able proportion." The limestones, therefore, from which these mortars were prei:)ared must have
contained the silica and magnesia as constituent ingredients ; and it is to be remembered that it is
the presence of these substances which communicates the property of hardening under water.
Professor Scorgie says of carbonate of magnesia : " Magnesium carbonate is a substance very
similar to carbonate of lime ; it loses its carbonic acid in burning, combines with silica, &c., and
behaves generally in the same way ; it does not slake, howe\er, on being wetted, but combines
with the water gradually, and quietly sets to some extent in doing so. Magnesium carbonate,
combined with lime, reduces the energy of the slaking, and increases that of the ' setting ' processes ;
when other substances are present, its beha\iour and combination with them are similar to those of
lime. When carbonate of magnesia is pre.sent in sufficient quantitj-, say about 30 per cent., it
renders lime hydraulic independently of and in the absence of clay." Colonel Pasley also, bj-
experiments, demonstrated that magnesian limestones are suitable for hydraulic mortars.

The foregoing assertions that magnesium carbonate, combined with lime, reduces the energy
of the slaking and increases that of the " setting " processes are satisfactory and conclusive. Many

4^ Plastering — Plain a//ti Decorative.

sucli evidences showint; the \alue of magnesia in hydraulic mortars miylit be quoted, but perhaps
these are sufficient.

Ekkects of Salt and Frost in Mortars. — Few experiments have as jet been made to
test the general effects of salt in mortars, though as a prcvcnti\c of the effects of frost it has been
tried with varj-ing results.

In some German experiments, designed to ascertain the effect of frost upon hj-draulic limes
and cement gauged with and without the addition of salt to the water, cubes of stones were joined
together with cement mixed with water ranging from pure rain water to water containing from
2 to 8 per cent, of salt. Before the cement was set. the blocks were exposed in air at a
temperature varying from 20 to 32 degrees Fahr., after which they were kept for seven da\-s in a
warm room. At the end of this time the samples were e.xamined. The cement made with water
was quite crumbled, and had lost all its tenacity. The cement made with water containing 2 jser
cent, was in better condition, but could not be described as good ; while that containing 8 per
cent, of salt had not suffered from its exposure to the lowest temperature available for the purpose
of experiment. It is suggested as possible that the effect of the salt was merely to prevent the
water in which it was dissolved freezing at the temperature named, and so permitted the cement to
set in the ordinarj- way. But it must be allowed that in practice, salt dissolved in the water for
mixing mortar has been successfully u.scd to resist the effect of frost. A solution of salt applied to
new plastered walls in the event of a sudden frost will protect the work from injurj-. The addition
of a small portion of sugar will improve its adhesion, and increase the frost-resisting pov/ers.

Salt takes up the vapours from the atmosphere, causing the work to show efflorescence, and in
some instances to flake, especially in external w nrk. That some engineers believe there is virtue
in salt water is beyond doubt, because salt water has been named in their specifications for the
gauging of concrete. Salt in Portland cement seems to act somewhat differently ; as regards
efflorescence it shows more in this material than in lime mortar. Salt should not be used in
Portland cement work that has to be subsequently painted. According to the results of tests of
mortar used for the exterior brick facing of the Forth Bridge piers below water they show a good
average tensile strength. One part of Portland cement and one part of sand were slightly ground
together in a mill with salt water, and briquettes made from this gauge gave an average of 365 lbs.
per square inch at one week, and 510 lbs. at five weeks after gauging. It would be interesting to
note the condition of this mortar a century hence, time being the trying test for all mortars.

A solution of commercial glycerine mixed with the setting stuff, or used as a wash on newly
finished lime plaster work, is a good preventive of the evil effects of frost. Glycerine solution
may also be used for the same purpose on new concrete paving. Strong sugar water mixed
with coarse stuff has some power in resisting frost. The quantity depends upon the class of lime,
but the average is about 8 lbs. of sugar to i cubic yard of coarse stuff or setting stuff The
sugar must be dissolved in hot water, and the stuff used as stiff as possible.

Sugar with Cement. — Sugar or other saccharine matter mixed with cement has been tried
with varying success. It is well known that saccharine is u.sed with mortars in India. According
to some experiments made in America, the results obtained were that the addition of sugar or
molasses delayed the setting of the mortar, the retardation being greater when molasses were used.
When certain proportions were not exceeded, the strength of the mixture was that of the pure
cement. Less than 2 per cent, of sugar must be added to Portland cement, and less than i
per cent, to Roman, otherwise the mortar will not hold together. The sugar appears to have no
chemical action on the other materials, crystals of it being easily detected on the broken surfaces.

Sugar ill Cements and Mortars. 49

the increased binding power of the cement brought about by the addition of sugar being due more
to mechanical than chemical causes. In my own experiments with sugar added to Portland
cement for casting deep undercut ornament figures and animals out of gelatine moulds, the results
at first were very irregular, some casts attaining great hardness, while others crumbled to pieces.
The time of setting also varied considerably. Three different brands of cement were used, and it
was found that the cement containing the most lime required more sugar than the lowest limed
cement, but the average is about li per cent, of added sugar. The sugar must be dissolved in the
water used for gauging. The setting and ultimate hardness is also influenced by the atmosphere.
The casts should be kept in a dry place until set and dry, before exposing them to damp or wet.
Portland cement has a tendency (especiallj- if over limed) to "fur" gelatine moulds, but the
sugared cement left the moulds quite clean.

In experiments b_\- Austrian plasterers, mi.xtures of i part of cement and 3 parts sand,
and 10 per cent, of water, and of pure cement with as much water as was necessary to give the
mass plasticity, were prepared. From i to 5 per cent, of powdered sugar was well mi.xed with
the dry cement. The cement used was of inferior quality, the sand being ordinary building sand,
and not the so-called "normal " sand, which is of a superior qualit}-. They were left to harden in
a dry' place, and not underwater. For each series of samples made with sugar a comparative
series without sugar were prepared, all the samples being made by the same man, under the
same conditions, and with the same care. The tenacity was ascertained by Kraft's cement-testing
machine. The strength was far below that prescribed and generally obtained. It should be
mentioned that the samples with sugar (especially those of pure cement) showed a strong tendency
during the first twenty-four hours to combine intimately with the smooth china plate on which
they were placed to swell, and the results of the trials showed that with mixtures of cement and
sand, and by hardening in a dry place, the binding effect may be increased b)- the addition of
sugar, which reached its maximum with from 3 to 4 per cent, of sugar added. With pure cement
the binding effect was not much increased. I think if the sugar used for gauging had been
dissolved, and not mixed drj-, the results would have proved better.

Sugar in Mortar. — Most writers have supposed that the " old Roman mortars " contained
strong ale, wort, or other saccharine matter, and it is probable that the use of sugar with lime
passed from India to Egypt and Rome, and that malt or other saccharine matter was used in their
mortars. The addition of sugar to water enables it to take up about 14 times more lime than
water by itself. The following is an extract from the Roorkee : " It is common in this country to
mi.x a small quantity of the coarsest sugar, ' goor,' or 'jaghery,' as it is termed in India, with the
water used for mixing up mortar. Where fat limes alone can be produced, their bad qualities may
in some degree be corrected by it, as its influence is very great in the first solidification of mortar.
This is attributed to the fact that mortars made of shell lime have stood the action of the weather
for centuiies owing to this mi.xture of 'jaghery' in their composition. Experiments were made on
bricks joined together b\- mortar, consisting of i part of common shell lime to lA of sand ; i lb. of
'jaghery ' being mixed with each gallon of water. The bricks were left for thirteen hours, and after
that time the average breaking weight of the joints in twenty trials was 6i lbs. per square inch.
In twent\--one specimens joined with the same mortar, but without the 'jaghcr\-,' the breaking
weight was 4.} lbs. per square inch."

The Madras plasterers make most beautiful plaster work, almost like enamelled tiles, the shell
lime being mixed with "jaghery." The surface takes a fine polish, and is as hard as marble, but it
requires a good deal of patient manipulation.

so Plastering — Plain and Decorative.

Dr Compton has made some experiments with sugar gauged with cements and mortars, and
says: " That in medicine there arc two kinds of lime water, one the common hme water that can
be got by mixing lime and water, and it is particularly noted that, add as much lime as you
like, it is impossible to get water to dissolve more than half a grain of lime in one ounce, or
about two small teaspoonfuls of water. But by adding 2 parts of white sugar to i part of
lime, there is a solution obtained which contains about 14A times more lime in the same quantity
of water. Here it is to be observed — and it is a most important ixjint — that there are hot limes,
such as Huxton, which, if they be incautiously mixed with them, will burn the sugar, make it a
deep brown colour, and convert it into other chemical forms, and possibly destroy its \aluc in
mortar."

The "jaghery " sugar used in India is sold in the London market at about a penny a pound.
Treacle seems to be the most promising form of saccharine matter ; beetroot sugar is not good
for limes or cements. There is a rough unrefined treacle which is very cheap, and it is supposed
would have an excellent effect.

Herzfeld states that he u.sed coarse stuff, consisting of i part of lime to 3 of .sand, to
which about 2 per cent, of sugar had been added, to plaster some walls in the new buildings
of the Berlin Natural History Museum, and on the day following he found the lim-e plaster had
hardened as if gauged \\ ith jjlaster. He also found it useful in joining bricks, and recommends
the coarse stuff to be fresh made, and not with a great proportion of water ; and states that good
molasses will )Meld as good results as sugar.

Lime Puttv. — This material is prepared in a similar way to run lime intended for coarse
stuff. It is run through a finer sieve into a box or pit. If ihc latter is used, the interior .should
be plastered with coarse stuff" to prevent leakage, and keep the putty clean. For good work, the
best class of lump lime should be u.sed. The puttj' should be allow cd to stand for at least three
months before it is used. For common work, the lump lime, for making coarse stuff", puttj-, and
setting stuff", is often run into one pit. The putt}' at the end farthest from the sieve, being the
finest, is retained for puttj- and for making setting stuff ; and the remainder, or coarser [:)ortion,
being used for coarse stuff". In manj- instances the putty is left for months in an unprotected
state, during the progress of the building, which is wrong. It may be kept for an indefinite time
without injury if protected from the atmosphere, and therefore it should be covered up to resist
the action of the air, as it absorbs the carbonic acid gas, and thus becomes slightly carbonated, and
loses to a certain extent its causticity, and consequently its binding and hardening properties.

Pliny states that the old Roman limes were kept in covered pits. If a small portion is taken
off" the top of the putty, it will be found not only <lr>-, but scaly, short, and inert ; whereas a
portion taken from the middle, or up to the part carbonated, will be found to be of an oily and
tenacious nature. .A cute plasterer al\va>-s selects the putt}- farthest froin the sieve for mitring
purposes, as it is the finest.

Setting Stuff. — This material is composed of lime putty and washed fine sharp sand.
The proportion of sand varies according to the class of lime and kind of work, but the average
is 3 parts of sand to i of putty. The various proportions are given where required for the
different works. Setting .stuff is used for finishing coat of lime plastering. It is generally made
on a platform of scaffold boards, and sometimes in a bin. The putty and sand are thoroughly
mixed together b\- aid of a larry. The sand should be sized by washing it through a sieve, having
a mesh of the desired size. In some districts it is made by pressing or beating the putty and
sand through a " punching sieve" into a tub. Setting stuff is less liable to shrink and crack, and

Hair and its Substitutes in Mortar. Si

is improved generall}-, if it is allowed to stand after being made until nearlj- hard, but not drj%
and then " knocked up " to the required consistency with water (preferably lime water), and the
aid of a shovel and larry. While the stuff is firming by evaporation, it should be covered up
to protect it from dust and atmospheric influences. It should be used as soon as "knocked up."
Setting stuff may be coloured to any desired tint, and also mixed with various ingredients to
obtain a brilliant and marble-like surface. (See " Coloured Setting " and " Stuccos.")

Haired Putty Setting. — Haired putty was formerly used to a very considerable extent as
a setting coat in districts where the local lime was of a strong or hydraulic nature, not very readily
manipulated when mixed with sand, as used for setting stuff. This material is composed of fine
lime putt\' and well-beaten white hair. The hair was thoroughly mixed with the putt\- to toughen
and prevent it from cracking. To such an extent was hair added, that in some instances the
setting coat, when broken, had the appearance of white felt. This class of setting stuff is now
seldom used, owing to the railway facilities for obtaining more suitable lime for the purpose.
Mr J. Welling, a prominent plasterer of Shrewsbury, who occasionally uses this material, informs
me that during some alterations at Cound Hall, erected about a century ago, he stripped from
the floating a piece of haired putty setting about 4 feet by 2 feet, and \ inch thick, which admitted
of being rolled up like a piece of felt, and with but little injury to it. This example proves the
toughness and flexibilit}- of haired putty setting, but also shows an apparent want of adhesiveness
or tenacit}', or it could not be stripped in such a large section. This is probably due to a lack of
knowledge on the part of the plasterer as to the nature of the material or the manipulation of
the same. It may also have been caused by an evil of almost everyday occurrence, viz., the
unkeying of the floating, and laying the setting coat on a dr\- absorptive surface. The numeroUs
instances where haired putty setting is inseparable from the floating go to prove its adhesiveness.

Lime Water. — This water has many medicinal virtues, and is a simple and inexpensive
remedy for cuts and bruises. Plasterers are generally healthy and free from manj- infectious
diseases. This ma\- be partly owing to their almost constant contact with lime. Lime water, used
as a wash, will harden plaster casts. It is also used when scouring and trowelling setting stuff
to harden the surface.

Hair. — Hair is used in coarse stuff as a binding medium, and gives more cohesion and
tenacity. It is usually o.K-hair (sometimes adulterated with the short hair of horses). Good hair
should be long, strong, and free from grease or other impurities. In England it is generally
obtained from plasterers'-hair merchants in a dry state in bags or bundles. This dry hair should
be well beaten with two laths to break up the lumps ; as, unless the lumps are thoroughly broken
so as to separate the hair, they are onlj' a waste, and worse than no hair at all, since the lumps
have no binding power, and will cause a soft weak spot in the plaster when laid. Many failures
of ceilings have been caused by the hair not being properly beaten and mixed. Human hair is
sometimes used for jerry work. Goats' hair is often chosen in America. Hair in Scotland is
usually obtained direct from the tanners' yard, fresh, and in a wet state. This makes the best work,
as it is much stronger, and mixes freely. Hair should never be mixed with hot lime, and with no
mortars, until nearlj- ready for using, because wet or hot lime weakens the hair, more especially
if dry. Coarse stuff for first coating on lath work requires more hair than for brick or stone
work. When coarse stuff is made in a mill, the hair should not be added until the stuff is ground,
as excessive grinding injures it.

Fibrous Substitute.s for Hair. — Manilla fibre, as a substitute for hair in plaster work,
has been the subject of experiments in America. One of the most conclusive of these tests was

52 Plastering — Plain and Decorative.

made by four briquettes or plates of equal size — one containing manilla hem]), a second sisal
hemp, a third jute, and a fourth of goats' hair of the best quality. The ends of the plates were
supported, and weights suspended from the middle. The result showed that plaster mi.xed with
goats' hair broke at 144^ Ib.s. weight, the jute at 145 lbs., the si.sal at 150, and the manilla at 195 —
in the latter ca.sc, the hemp not breaking, but cracking, and though cracked in the centre, the
lower half of this plate, when it was suspended, held on to the upper half, the manilla securing
it fast. The three other plates were broken — that is, the two parts of each plate had severed
entirely. Another experiment consisted in mixing two barrelfuls of mortar, each containing
equal [jortions bj- measure of sharp sand and lime, one of the barrels, however, being mixed
with a proper quantity by measure of manilla hemp, cut in lengths of li to 2 inches, and the
other of best goats' hair. On being thoroughly mixed with the usual quantity of water, the
respective compounds were put in the barrels and stored away in a dry cellar, remaining unopened
for nine months. On examination, the hair mortar crumbled and broke apart, very little of the
hair being visible, showing that the hair had been con.sumed by the action of the lime ; but the
other, containing the hemp, showed great cohesion. It required quite an effort to pull it apart,
the hemp fibre permeating the mass and showing little or no evidence of any injurj- done to it
by the lime.

S.WVDUST AS A Substitute for Hair. — Sawdust has been used as a substitute for hair, al.so
for sand in mortar for wall plastering. It makes a cheap additional aggregate for coarse stuff.
Sawdust mortar stands the effects of rough weather and frost when used for external plastering.
The sawdust should be used dry, and put through a coarse sieve to exclude large particles. I
nave used it w itli plaster for both run and cast work ; it proved useful for breaks of heavy
cornices, by rendering the work strong and light for handling. Some kinds require soaking or
washing, otherwise they are liable to stain the plaster. Several patents have been issued in
America for the use of sawdust in place of hair and of sand. One of these is for the use of equal
parts of plaster or lime and sawdust ; another is for the use of 4^ jjarts each slaked lime and
sawdust to I part of plaster, \ part of glue, and jV P^rt of glycerine, with a small part of hair.
Kahl's patent plaster consists of 35 per cent, of sawdust, 35 per cent, of sand, 10 per cent, of plaster,
10 per cent, of glue, and 10 per cent, of whiting.

Sand. — Sand is the most widely distributed substance in nature, not only in the mineral, but
al.so in the animal and vegetable kingdoms. Clay contains no silica (the chemical name for .sand).
Sand is the siliceous particles of rocks containing quartz, produced by the action of rain, wind, wave,
and frost. Some kinds of sand are also found inland ; the deposits mark the sites of ancient beaches
or river beds. Sand is classed under various heads, viz., calcareous, argillaceous, and metallic. Sand
varies in colour according to the metallic oxides contained in them. Few substances are of more
importance than sand for plastic purposes. Its quality is of primary importance for the production
of good coarse stuff, setting stuff, and for gauging with Portland or other cements used for plaster
work. Its function is to induce the mortar or cement to shrink uniformly during the process of
setting, hardening, or drying, irregular shrinkage being the general cause of cracking. Sand is also
a factor in solidity and hardness ; while being of itself cheaper, and used in a larger proportion than
lime or cement, it decreases the general cost of materials. There are three kinds — pit, river, and
sea sands. They generally contain more or less impurities, such as loam, clay, earth, and salts,
necessitating their being well washed in water, more especially for the finishing coats of plaster or
cement work. Pit sand is .sometimes found quite clean ; it is generally sharp and angular. River
sand is fine grained, not so sharp as pit sand, but makes good setting stuff. Sea sand varies in

Sauds and Mastics. 53

sharpness and size, and for plastering it should be washed, to free it from saline particles which
cause efflorescence.

Regarding the use of sand in mortars, it may almost be spoken of as a necessary- evil. Sand is
necessary to give body and hardness to an otherwise too soft and plastic material, and the coarser
and cleaner the better, as the coarse particles allow the carbonic acid to penetrate farther into the
body of the mortar, and assist in the hardening process for this reason. In the case of cements of
all kinds sand is only good for lessening the cost of the aggregate, and in the case of the majority
of sands in daily use in most places the strength is reduced out of all proportion to the saving
effected. Brunei, in making the Thames Tunnel, was so convinced of this that he used pure
Portland cement in the arches ; and General Paslej', treating of this, recommends that only pure
cement should be used on all arduous works.

As to the quality of sands, they are of very wide variety — so much .so, that i part of an inferior
or soft clayey sand will reduce the strength of mortar as much as 3 or 4 parts of clean sharp,
granitic sand. This is well exemplified in the sand test, which is made with what is called standard
sand, being a pure silicious sand sifted through a sieve of 400 holes to the square inch, and retained
on one of 900.

Good sand for lime plaster should be hard, sharp, gritt}-, and free from all organic matter. For
coarse stuff and cement for floating coats it should not be too fine. Good sand for plaster work may
be rubbed between the hands without soiling them. The presence of salt in sand and water is
found not to impair the ultimate strength of most mortars ; nevertheless it causes an efflorescence of
white frothy blotches on plaster surfaces. It also renders the mortar liable to retain moisture.

Fine-grained sand is best for hydraulic lime; the coarse-grained is best for fat limes, and
coarse stuff and Portland cements for floating. Sand should not be uniform in size, but, like
the aggregate for concrete, should vary in size and form. A composition of fine and coarse sand
for coarse stuff, unless the sand is naturally so mixed, gives the best results ; for as the lime
will receive more sand in that way without losing its plasticity, it will make a harder and stronger
material, whether coarse stuff, setting stuff, or for Portland cement work. If there is plenty of fine
sand and a scarcity of coarse sand, they should be mixed in the proportion of 3 of coarse to i of
fine. If, on the other hand, there is plenty of coarse sand and a scarcity of fine, they should be
mixed in the proportion of 2 of fine to i ofcoar.se. The proportion of sand varies according to the
different kinds and qualities of limes and cements, also purposes, and is given under the various
heads. Barytes is sometimes used as a substitute for sand. Silver sand is used for Portland
cement work when a light colour and a fine texture is required. Silver sand is chiefly obtained
at Leighton Buzzard. Arnold's silver sand is extensively u.sed in London for cement work and
sgraffito. Tests of sand, &c., are given in Chapter XVIII.

M.\STIC. — Mastic was formerly extensively used for various purposes in which now Portland
cement is chiefly employed. It is still used in Scotland and the North of England for pointing the
joint between the wood frames of windows and the stone work. Mastic is waterproof, heat-
resisting, and adheres to stone, brick, metal, and glass with great tenacity-. Mastic is made in
various ways. Some plasterers make their own.

Scotch Mastic is composed of 14 parts of white or yellow sandstone, 3 parts of whiting,
and I part of litharge. These are mixed on a hot plate to e.xpel any moisture, and then sifted to
exclude any coarse particles. It is then gauged with raw and boiled linseed oil, in the proportion
of 2 of raw to i of boiled oil. The sandstone is pounded or ground to a fine powdered state before
being mixed. The surface to be covered is first brushed with linseed oil.

54 Plastering — Plain ami Decorative.

LoNiHiN Mastic is prepared as follows: — lOO parts of ground stone, 50 parts silver sand or
of fine river sand, and 15 parts of litharge. These arc all dried and mixed, and passed through a
fine sieve ; it then resembles fine sand. This mastic may be kept for any length of time in a dry
place. When required for use, it is gauged with raw and boiled linseed oil (in equal proportions)
until of the consistency of fine stuff. It requires long and frequent beating and kneading ; in fact,
the more it is knocked up the better it works. Its fitness for use can be ascertained by smoothing
a portion of the gauge with a trowel. If there are any separate parts of the different materials or
bright spots seen, the knocking-up must be renewed until it is of even texture. The addition of
15 parts of red lead is sometimes used to increase the tenacity of the mastic.

M.VSTIC M.VNIl'ULATION. — The walls are prepared for mastic by raking out the joints and
sweei)ing with a coarse broom, and the brick work well saturated with linseed oil. Narrow screeds
about I inch wide are formed in plaster to act as guides for floating the work plumb and level.
When laying the mastic, it must be firmly pressed on, and the floating rule carefull}' passed over
the surface until it is straight and flush. The screeds are next cut out, and the spaces filled in
with extra stiff mastic. The whole surface is then finished with a beech or sycamore hand float,
leaving a clo.se and uniform texture. Mastic mouldings are first roughed out with Medina or
other quick-setting cement. The running mould is muffled, so as to allow \ inch for the mastic
coat.

H.vmelein's Mastic. — This mastic con.sists of .sand and pulvcri.sed stone, china, pottery,
scharff, to which are added different oxides of lead, as litharge, gre>' oxide, and minium, all reduced
to powder, to which again is added pulverised glass or flint stone, the whole being intimatel)-
incorporated with lin.seed oil. The proportions of the ingredients are as follows : — To any given
weight of sand, or pulverised pottery ware, add two-thirds of the weight of pulverised Portland,
Hath, or an\- other stone of the same nature. Then to every 550 lbs. of this mixture, add 40 lbs. of
litharge, 2 lbs. of pulverised glass or flint stones, i lb. of minium, and 2 lbs. of grey oxide of lead.
The whole must be thoroughly mixed together and sifted through a sieve, the fineness of which
will dejjcnd on the different purposes for which the mastic is intended. The method of using
is as follows : — To everj' 30 lbs. of the mastic add i quart of lin.seed oil, and well mix together,
either b)' kneading or with a trowel. As it soon begins to .set, no more should be mixed at a time
than is requisite for present use. Walls or other surfaces to be plastered u ith this material must
first be brushed with linseed oil.

Mastic Cemext. — Mix 60 parts of slaked lime, 35 parts of fine sand, and 3 jjarts of litharge,
and knead them to a stiff" mass with 7 to 10 parts of old linseed oil. The whole mass must be
well beaten and incorporated until thoroughly plastic. This mastic cement assumes a fine smooth
surface by trowelling. It is impervious to damp, and is not affected hy atmospheric changes.

Ste.\r.\TE of Lime. — This lime is often used in America as a finishing coat to resist damp.
It is made b)" mixing i bushel of lime with 20 lbs. of finely chopped suet, and adding boiling water
until the ingredients are thoroughly mixed and about the consistencj- of lime putt)'. The lime and
.suet are placed in a barrel, then the boiling water is poured on, and the whole worked together by
a revolving shaft, having arms at its lower end (somewhat similar to a " pug-mill "), until the mass
is thoroughly incorporated. Stearate may be applied hot with a brush, two coats generallj' being
sufficient. The suet undergoes a chemical change when mi.xed with the lime, and forms a com-
pound impervious to water, and as durable as paint. It makes an excellent paint for stone, brick, or
concrete. It can be made to assume any tint by the addition of stains.

CHAPTER III.

J/ A TERIALS—Continucd.

Manufacture, Analysis Tests, Compressive, Tensile, and Adhesive Strengths and Uses of
Cements— Portland, Slag, Wilkes and Millar's Metallic, Roman, Sheppev, Medina, Keen's,
Howe's, Parian, Robinson's, Adamant, Bassett's, Asbestic, Stone, and Paris Cements-
Manufacture AND Uses of Selenitic— Hydraulic Cements and Plasters— Granite, Sirapite,
Shale, Petrura, and American Patent Plasters— Black Finish— Lathing— Wood, Reed, Slate,
Wire, and Metal Lathing— Expended Metal, Jhilmil, Bostwick, Johnson's, Hay's, Patent
Metal Sheet Lathing, and Helical Metal Lathing.

Cements. — The earliest known patent for cement was obtained in 1677 by Kendricks Edisbury,
for " a certaine sort of Plaister of an E.xtraordinar}- Hardness called ' Glassis ' which may be used
instead of Freestone for paving of Floors and Water Mills for grinding corn." There is a long
specification in legal phrase about protecting the inventor and his exhibition, &c., but not a word
about the materials or process ; because at that time inventors were not bound to disclose their
process and method of manufacture. Cements are composed of finely ground lime or other
substances, which are used alone or mixed with other materials, so that they will set on the addition
of water. They are usually divided into natural and artificial cements. Roman cement, plaster of
Paris, and similar cements are natural cements ; Portland cement, slag, and similar cements are
artificial cements.

PORTL.\ND Cement. — Portland cement was patented by Joseph Aspdin, a bricklajer and
plasterer of Leeds, in 1824. His son, William .Aspdin, was one of the earliest makers of Portland
cement, having a manufactory at Wakefield. He afterwards associated himself with Messrs Maude,
Son, & Co., and in 1843 started a manufactory at Rotherhithe, on the banks of the Thames.
Aspdin also obtained a patent in 1825 for a concrete of lime, road scrapings, &c., for artificial stone.
In 1852 his son William obtained a patent for an improved method of manufacture of Portland
cement. Portland cement is obtained by a careful combination of three well-known minerals, viz.,
carbonate of lime, alumina, and silica. This combination can be arrived at by the admi.xture of
various materials, and even from waste products, such as the slag from iron districts and alkali
waste from the soda and other cognate manufactures. But the materials from which it is generally
made are chalk and clay or mud. Its advantages over all other cements are — its hydraulic
properties, great strength at comparatively early dates, its continuallj- increasing strength, and its
power of carrj'ing very large proportions of sand or other aggregate when made into mortar or concrete.
The process of manufacture ma}- be di\ided as follows: — (i) Getting the chalk and clay; (2) mi.xing
the chalk and clay in certain proportions, and producing slurry ; (3) drying the slurry ; (4) burning
the dried slurry called "slip"; (5) crushing the clinker ; (6) grinding the crushed clinker; and (7)
producing the finished cement. In the process of mixing or washing, the chalk and mud — in the
proportion of about 3 to i when mud is used, and 4 to i when using claj- — are tipped into the wash-

S6 P/asfcn'iii: — P/aii/ ai/d Decorative.

mill. This consists of a circular brick pit sunk into the ground, in the centre of wliich rcvol\cs a
vertical shaft carr)ing four or more horizontal arms, from which depend harrows, the tines of whicii
in their course break the lumps, and keep the whole mass in a violent state of agitation. Water is
used as required until a stiff paste is formed. When it is in a sufficient state of pulverisation it
passes through a grating and falls into a pit, from which it is carried by an elevator into a tank at a
considerable height from the ground.

The e.xact proportions of the chalk and ciaj- cannot be dcfinitelj- fixed, as the material ma_\-
vary in composition in different parts of the quarrj- or pit, and in wet weather may have absorbed
a quantit)- of water before reaching the wash-mill, the amount of which cannot be arrived at by
mechanical means. To get at this proportion, some manufacturers burn off a small sam])lc kiln
daily, convert it into cement, and apply the usual tests for tensile strain, soundness, &c. ; but as
the result of this experiment is not arrived at until too late to rectify the evil, if any, it is of little
value except for future guidance, and perhaps the advantage (if the result is obtained in time, and
is unsatisfactory) of being able to prevent the cement to which the sample belonged being bulked
in the warehouse with good qualities.

A quicker and altogether more satisfactorj- test is obtained b)- an apparatus called a calcimetcr.
In this operation a fixed quantity of hydrochloric acid, and a given quantity of "slurry" taken
from the wash-mill and thoroughly dried (the quantit)- \arying slight))- with the variations of
barometer and thermometer i, arc put together in a sealed vessel, one end of which is connected b\-
a pipe with a L' -shaped glass tube partly filled with water. The carbonic acid gas generated by the
mixture of the acid with the carbonate of lime depresses the water in the leg of the column to
which it is attached, and it ]ia\ing been decided b\- experience to what extent this depression
should occur in order to make good cement, it will be seen that too great a depression means too
much carbonate of lime, or, in other words, too much chalk, and vice versa.

From the tank the slurr)' descends to the wet-mill, and is ground between buir-stones to
ensure the perfect reduction of the coarse particles ; or it is run llirough centrifugal separating
sieves, the coarser particles, which will not pass through the meshes, returning to the wash-mill pit
to be further agitated and reduced. From the stones it falls by gravitation into a sump, from
whence it is pumped in a semi-fluid state on to fire-tiled floors, under which are arranged flues
taking the heat from furnaces placed at one end. \Micn ])erfectly dr\' the sknr)- is broken with a
crowbar into lumps of, say, 6-inch cube, and carried to the kilns, which are loaded with alternate
layers of coke and the dried slurrj-, now called "slip." Faggots are placed at the bottom of the
kiln to start the fire, and the kilns take about five da\-s to burn off. After allowing a few hours to
cool, the fire-bars are taken out, and the contents withdrawn in the form of " clinker." This is a
hard, lava-like substance, of considerable specific gra\ity, and maj- be compared to the " pig " of the
iron furnace. It is wheeled awaj' and passed through a crushing-machine, which breaks it into
cubes of, say, li inches. These are carried bj- an elevator into a hopper over the grinding or dry
mill, which is fitted with burr or emery stones, edge runners, or some form of disintegrator, which
reduce it to a fine powder. The powder is elevated to the level of a horizontal worm, which
conveys it to the warehouse, and when air-slaked it is ready for use.

The kilns used in connection with the fire-tiled floors are called bottle-kilns from their shape;
but in order to save the expense of the fuel used in drying the slurry, they are giving way to kilns
in which the heat, while " turning off," passes under and over a horizontal chamber on which is
pumped the slurry for the next charge, thereb\- drying it in readiness to reload the kiln.

The colour of cement should be a deep grey. It is conceded by the best authorities that a

Portland Cement — Manufacture and Analysis.

weight of 1 12 lbs. per bushel gives satisfactory results. It should have a specific gravity of about
3.10. This is the better test of its proper calcination, as the weight per bushel varies according to
the grinding. The finer the grinding, the less the weight, while the specific gravity of course remains
the same. The weight test is the most useless of all.

The colour when gauged and dry should be of a light grey. A brown or foxy colour denotes
an over-clayed or unburnt cement. Different brands of Portland cement may be equally good in
strength and durability, yet differ slightly in composition when analysed. The following is an
analysis of two different brands of Portland cement. The first is by H. Faija. of a Portland cement
made on the Thames. The second is by A. E. Carey, of a Portland cement made at Stockton,
near Rugby : —

Table IV. — Analysis of Portland Ck.mknt.

Lime. : Silica. Alumina.

No. 1

No. 2

61.76 ' 20.54
61.5

9.90
22.22 1 10.10

Oxide of

Sulphuric
Acid.

Soda and

Olher

2.04

3-19

0.71
0.85

1-34

2.92
1.25

Great care should be exercised in the selection of Portland cement, and it is safer to deal
with manufacturers of good repute. Some manufacturers mi.x Kentish rag and other stones,
furnace ashes, disused or exhausted fire-bricks, or other inert material, thus bringing disrepute
upon the good name English cement has hitherto borne in comparison as to quality with cement
of foreign manufacture, and entailing unsound and unsatisfactory work at home.

Having now detailed the process of manufacture, the chief qualities of Portland cement may
be enumerated as follows: — (i) Setting and hardening properties; (2) consistency of volume;
(3) permanence in water and air ; (4) strength under tension and compression ; (5) impermeability
by water ; (6) resistance to wear; (7) resistance to fire ; (8) adhesion to brick and stone.

Briquettes. — Briquettes are small blocks of gauged cement or other material, which are
used to test the tensile strength of the material by drawing them apart by means of a machine.
Various forms and sizes of briquettes have been used. The earliest kinds were \\ inches, 2 inches,
and 2\ inches square at the waist, or smallest part where the fracture would occur, but the\- are now
general!)- made i inch square at the waist. This size is more convenient, and can be tested with
less powerful machines.

Briquettes allowed to harden in the air absorb carbonic acid gas from the atmosphere to the
extent of about 6 per cent, in the first six months, while cement immersed in water remains free
from it. The briquettes kept in water, and therefore free from carbonic acid gas, offer about
twice as much resistance to compression than the others. Between the ages of one and six months
briquettes made with quick-setting cement give lower results than they would for slow-setting.
A briquette of neat cement is more brittle than one of concrete. The maximum strength of a
briquette of matured cement is maintained, while one of new cement " goes back."

Water for Briquettes. — The quantity of water should always be the same when making
briquettes, and the results with the same cement will then be more uniform. All other things
being equal, a cement that will not take up its full quantity of water, 10 to 25 per cent, of its
weight, is not so good as one that does. Briquettes gauged with 20 oz. of water to 100 of cement

58 f/dsfo'iiig — f/dii/ iiihi Decorative.

will give better tensile results than those gauged with 30 oz. of water to 100 of cement. The
former gauge is rather drj- or stiff, and it must be carefully rammed into the moulds. A good
cement, not too old, will e.xpantl in setting, and completely fill up the space allotted to it, whereas
an old cement will not do so, and consequentK" spaces are left for water to enter and weaken it.
The water should be i^erfectl}- clean and cold. When hot water is used for special purposes, the
temperature should be noted for future reference.

G.\L'c;iXc; KOR Hkk^UETTE-S. — The gauging of the mortar for briquettes for testing should be
done upon glass, porcelain, slate, or other non-absorbent surface. It must be done thoroughly,
rapidly, and in a constant temperature between 60 and 70 I'ahr. l"or Portland cements use i
part cement and 3 parts sand, and for natural cements i part cement and i part sand. The
pro]5ortions are hy weight. ^lix thoroughl)-, and then add sufficient water to gi\e the mass the
consistenc)- of damp sand. To obtain good results, as little water should be used as jjossible, the
actual amount depending upon the quality of both the sand and cement, and also the projjortions in
which the)' are u.sed. There is little danger of using too little water, only 20 to 25 per cent, being
required for neat cement, 15 per cent, for i part of sand, and 10 to 12 per cent, for 3 ]5arts of sand.
These percentages are in proportion to the combined weight of the cement and sand. In preparing
a (juantit)- of cemcTit for neat or sand briquettes, this mixture should be thoroughly kneaded by
hand, and afterwards trowelled until perfectly homogeneous. For neat tests, the cement should
be worked until it sheds water, and with sand until all the grains are covered.

When the sand and cement are thoroughly incorporated, the mortar is pres.sed into oiled
moulds, w ith sufficient pressure to exclude all air bubbles and make the briquettes compact and
uniform. After filling, the moulds .should be smoothed off on both sides with a trowel, and laid
away under a damp cloth for twenty-four hours, when the briquettes should be removed from the
moulds and immersed in water of 65 or 70° Fahr., care being taken that they are completely sub-
merged. In making briquettes bj- hand, it is usual to mix only sufficient mortar to make five tests.
With a larger quantit)- there is danger of an incipient set, and the necessity of rew orking the mortar.
The evils attending this operation are well understood, and it is for this reason that several machines
have been designed hy the use of which briquettes are not only made much faster, but ensure a
much greater uniformit}-, the variation being reduced to about 2 |)cr cent. To make five briquettes
of standard size of the neat cements requires about \\ lbs. of material ; and for those containing 1
part of cement to 3 of sand, about 6 oz. of cement and \\ lbs. of sand.

SiF.viNc;. — In tests for fineness of Portland cement three sieves are used — No. 50 sieve, 2,500
meshes to the .square inch, made of N'o. 35 w ire. Stubs' wire gauge ; No. 74 sieve, 5,476 meshes to
the square inch, made of No. 37 wire ; and No. lOO sieve, 10,000 meshes to the square inch, made of
No. 40 wire. A weighed amount of cement is taken and sieved with the No. 50 sieve. What passes
through is carefully weighed, and its percentage of the original amount calculated. A similar
amount of cement is taken and tested on the No. 74 sieve, and similarlj- on the No. 100 sieve, the
|jercentage passing through being calculated. These measurements are made on a small scale
weighing to o.oooi lb. I-'or comparative tests, briquettes should be made with cement that has passed
through a No. 100 sieve, but for a particular piece of work the cement should be used as it comes
in the bag or barrel. When tests are made to determine the value of a cement for any particular
piece of work, the sand used should be the same as is to be used in the work ; but for comparative
tests it is necessary to use a standard sand that can readily be duplicated. For this purpose
crushed quartz is used, the degree of fineness being such as to pass a No. 20 sieve and be caught on
a No. 30 sieve.

Porthuid Cement — Testing.

Testing Machines. — There are several kinds of machines for ascertaining the tensile
strength. Among them may be mentioned those of Adie, Bailey, Studt Michele, Kuhlmann,
and Faija. Cement-testing machines are all nearly constructed on the same principle.

The aim in the construction of Adie's machines was absolute permanence and non-inter-
ference of the hand of the operator. Thus all springs and screws were dispensed with, and
the simple steel beam and weight travelling on rollers adopted, that pulled by a light cord, which
need not be fixed to the weight, the hand can thus only affect the forked pillar, which does not
touch the beam in testing. To make this more unquestionable, in addition to the speed-reducing
wheel and pinion a patent automatic regulator can be added. The subjoined illustration (\o. 12)
shows the automatic speed regulator. This carries the weight uniformly, at a certain speed,
on the beam, so as to be quite independent of the hand of the operator, a very necessary
improvement. If the standard A be not in its place when received from the manufacturer,
bolt it down to the stand, so that the beam when strained (by putting a moulded brick of
cement into the clips B and
C, and then tightening by
means of a wheel under-
neath at D) may take its
position freely in the centre
of fork E. Wind the cord
once round the pulley at A,
and twice round that at E.
Mix the cement to be tested
with as little water as pos-
sible, consistent with per-
fect homogeneity, and hav-
ing laid the mould on a flat
surface, or on the iron plate
supplied for the purpose, fill
it with the cement as de-
scribed, and scrape the top
flush. When set, take the Xo. 12.— CE>!ENT-TEsriNc. Machixf..

briquette out of the mould

carefuU)-. This is done by releasing some screws simultaneously, thus releasing the sides, and place
it on the flat plate in water for .seven da}-s ; it will then be ready for testing. To effect this, place
it in the clips, turn the wheel at D till they clasp the brick with sufficient force to raise the end of
the beam nearly up to the pulley above. H is the elevation of the briquette mould. The scale pan
on the bench of the testing machine is used for weighing small quantities of cement, or indeed any-
thing, as the machine acts as an ordinary weighing machine. The pan suspended beneath the bench
will contain one-tenth of a bushel of cement, that quantity being most convenient to weigh. (<?.) For
strains from o to 130 lbs., using the bottom row of figures, hang the transferable weight Y in the
notch at the end of the beam (as shown in the drawing) and roll the vernier weight c; along,
taking about one minute to travel the length of the beam, {b) From 90 to 200 lbs., using the
middle row of figures, remove F from the machine, and roll G forward as before, {c) Above 150 lbs.,
using the top row of figures, hang on F in the notch under G, and roll G (carrj-ing F with it) forward
as before. To use as a weighing machine, remove the sliding block carrying D and t' ; take out the

6o Plastering — Plain and Decorative.

top cli[) I!, and lian^ on the scale pan instead. A hook passing through a hole in the stand can be
supplied with one-tenth bushel measure to weigh the cement if required.

An excellent and accurate cement tester (Kuhlmann's patent; is manufactured by Messrs
G. Salter & Co. This machine is used by man)' of the |)rincipal cement manufacturers and
contractors in Kngland and abroad.

The Needle Test. — The rapidity with which a cement loses its plasticit)- shows its initial
hj'draulic activit)-. Cements that set in less than half an hour are termed quick setting, and those
rctiuiring a longer period slow .setting. Ouick-.setting cements should not be worked longer than a
minute, or slow-setting longer than three minutes. As .soon as the cement has assumed sufficient
hardness to bear the gentle pressure of the finger nail, it is considered as beginning to .set. The
time of setting is usually measured bv the penetration of a steel point, termed "The Needle Test."
This test was first used in this countr)- by General O. A. Gillmore, and consists of a jli-inch wire
loaded with \ lb., and a 5 4 -inch wire loaded with i lb. Pats are made of neat cement about 2\
inches in diameter, A inch thick in the centre, and ] inch thick at the edges. I'or the initial .set,
the time is recorded from when they are made to the time when thej- will su]jport the \-\\>. weight
without making an impression, and the final set until they will sujjport the i-lb. weight. If the pats
will not bear the \-Vo. weight after five hours the cement should be rejected.

Checking; Test. — The test for checking or cracking is frequently used. Make two pats of
neat cement, same as for the setting test, and note the time it takes to set hard enough to bear the
4-lb. and i-lb. loads. When hard enough, one of these cakes should be placed in water and
examined from day to day to see if there are any indications of contortions or cracks. The other
pat should be kept in the air and its colour observed, which, for a good cement, .should be free from
blotches.

HuiLlxc; Test. — Make a briquette or thin cake of neat cement as above, allow it to .set hard in
the air with a damp cloth over it for twenty-four hours, then immerse in boiling water and boil for
twentj--four hours. This boiling causes the coarse grain to disintegrate, and if there is an excess of
free lime in the cement, the caustic lime, becoming h>-drated, swells and causes the cake to crack.
This cracking and disintegrating is called " blowing," and any cement acting this way .should be
rejected. Care must be taken, however, not to confuse the fine hair lines found on the surface which
cross and recross each other with the coarser wedge-shaped cracks due to swelling or blowing, for
the fine lines are merel\- the result of slight changes in temperature and do not denote a poor
cement. This test should be used in conjunction with the sand test and test for fineness to
determine accurately the quality of the cement.

Tensile Test. — The test for tensile .strength is the mo.st common of all tests, though not a
perfect indication of the value of a cement. It is frequently the only test used in comparisons of
different kinds, but the results obtained from neat cements do not give uniform conclusions
regarding the binding properties of the cement and sand. In comparing several varieties of cement,
it is necessary to u.se a high percentage of sand, as the setting properties of different varieties vary
much with the amount of sand. A proportion (b>- weight) of i part cement to 3 of sand is taken as
the standard for Portland cements, and equal parts of sand and cement for natural cements.

After the briquette has attained the requisite age, it is placed in the testing machine and sub-
jected to a .strain of 400 lbs. per minute until fractured. In adjusting the clips to the specimen the
greatest care must be cxerci.sed that everjthing comes to a full and even bearing, as carelessness in
this respect leads to a greater variation in results than from anj- other cause. Briquettes for tensile
tests are left one day in air and one day in water, or one day in air and six days in water, or one

Tensile ami Compressive Strength of Portland Cement. 6i

day in air and twenU'-seven da_\-s in water. These three are the usual tests, though the briquettes
are sometimes allowed to remain in water as long as a year.

The tensile strain of Portland cement is generally specified at from 350 to 400 lbs. in
the square inch for neat cement seven days old, the briquette to be immersed in water twenty-
four hours after being made. The strain should be applied at a speed of 100 lbs. per fifteen seconds.
Briquettes should also be made with a mixture of i part of cement to 3 of clean sharp sand,
and immersed in water twenty-four hours after being gauged. They should stand a strain of 250 lbs.
per square inch seven days after gauging. The grains of sand should be of uniform size, and only
those portions should be employed which have passed through a sieve 900 meshes per square inch,
and been retained by one 1,600 meshes to the square inch. The value of a cement is best
determined by the strength of a mixture of cement and sand (i to 3 tested at twenty-eight days),
and not by the strength of the cement alone, because practically cement is never used alone in
actual work, but generally with sand or some other aggregate. Sand varies greatly in hardness
and strength, therefore the sand used for the test should be of the kind which would be used for
the actual work. This would give a knowledge of the strength to which the intended work might
be expected to attain. When ascertaining the strength of Portland cement the average of not less
than three tests should be taken. Portland cement is weakened by the addition of sand or other
aggregate. At the end of one j-ear after setting —

1 of sand and i of cement is about \ the strength of neat ceinent.

2 1 ,. i

3 I .. i „

4 I „ i „ „ .

The strain a hand-made briquette will stand depends in a great measure upon the skill of the
manipulator, as it is evident that any one accustomed to the work will be able to gauge with less water
and in less time than a novice. To be able to form a true opinion of the value of cement, briquettes
should be tested when practicable at twenty-eight days, as well as at seven, as the greater the
increase between these dates, the stronger the cement is likely to become. The deduction which
has been arrived at by a series of tests of tensile strength is that the quick-setting cements and
those which acquire great strength in a short time do not as a rule continue to increase in strength
after a few months, and that after they have attained their ultimate strength the\- have a tendency
to fall off Some manufacturers guarantee a strength of 450 lbs. per square inch at the age of
seven days. Some cements have given a tensile strength of 700 lbs. at seven days, but as they
show little increase of strength afterwards, they most likely contain too much lime, and are there-
fore somewhat unsafe. Provided a cement is sound and sufficient!)- fine, it will bear a tensile strain
of 350 lbs. per square inch at the age of seven daj-s. It may be accepted for nearly all kinds of work.

Compressive Strength. — Testing by compression is useful to indicate the stress the
concrete will bear in certain parts of a building, such as arches. The briquettes should be
composed of the same kind and proportions of materials as intended for the actual work. The
compressive resistance of briquettes composed of i part of Portland cement to 3 of sand varies
from 8 to 12 times greater than tensile strength. Mr Faija found, from the average of three
tests of i-inch cubes made from four cements, that at the age of twenty -eight days the resistance to
crushing varied from 4,270 lbs. to 4,780 lbs., and the resistance to tension from 480 lbs. to 696 lbs.
Better results are obtained if larger cubes and bedded with plaster are used for testing, as the
slightest inequality of surface may cause fracture under a comparativelv- small stress.

62 Plastcy'uig — Plain ciini Dccoi'afh'c.

Tkansvkksi: Strength. — Portland cement may be sound, but only of moderate strength.
It is therefore necessary to test the strength, anil in the absence of a testing macliinc tlic following
method, as specified b>' Mr D. A. Stevenson, may be adopted : — "The cement is to be made into
blocks I inch square and S inches long; these are to be immersed in water for seven days, and
then tested b_\' being placed on two supports 6 inches apart, when they must stand the transverse
strain produced by a weight of 75 lbs. placed on the centre." This is a siinple way of testing.
Several briquettes should be tested to ascertain their average strength.

Fineness. — The test of fineness is the most important and valuable. Most specifications
agree on the point of fineness, which is generally that when sifted through a sieve having 2,500
holes (50 by 50) to the square inch it should leave a residue of not more than 10 per cent, by
weight, and that when sifted through a sieve with 625 holes (25 by 25) it shall leave practically
nothing. Manufacturers should sift all Portland cement to a .standard degree of fineness. The
residue or coarser parts retained on the sieves could be reground. The finer cement is ground, the
greater its adhesive strengtii, and the more sand it will carry. Finely ground cement only has any
cementitious value, the coarse particles being worthless, as they resist the action of water and cause
" blowing." This is caused by the coarse particles not being acted upon until after the finer
portions have set, the subsequent chemical union of the coarser parts and the water expanding and
damaging the cement which has already set. There is less need for storing and air-slaking cement
before using it if it has been ground very fine. In the early days of Portland cement a sieve
having 40 meshes to the lineal inch was used, sub.sequently one with 50 to the lineal inch (2,500
per square inch), and at the present time one with 75 to the lineal inch (5,625 per square inch) is
used to test the cement \>y sifting. German cement is ground imicli finer than English, and
Austiian still more so, a sieve of goo meshes being used (5,806 per square inch), not more than
10 \)<tx cent, supposed to be retained on the sieve after sifting. If a cement which has all passed
through a No. 40 sieve be sifted through a No. 75, the particles remaining on the latter will be
absolutely valueless as a cementitious agent.

SoUNDNES.s. — Testing Portland cement by the preliminary tests of colour, weight, and
fineness, or what tensile strength is developed within the period of an ordinary test, is of little
value if the cement proves unsound, or in the course of time will " blow." The test of " soundness,"
or absence of expansion or contraction, is the most important. Mr H. I-"aija has devised a test
which is at once quick and decisive. The method is to submit a freshly made pat of cement to a
moist atmosphere of about 100 Fahrenheit, and when set hard to immerse it for some
hours in water at a temperature of 115 F"ahrenheit. This treatment greatly expedites the
setting and hardening of cement, and in a like manner develops any blowing tendency which maj-
exist in it, and consequentl)- in the short space of twent)--four hours the soundness or unsoundness
of a cement may be absolutely determined. In the absence of a testing machine, certain tests
can be applied to show the soundness of cement. For instance, if a thin glass bottle is filled with
stiff-gauged neat cement, and after it has been set a few days the bottle is found to be cracked, it
shows it has either been manufactured with an e.xcess of lime, is not air-slaked, or the disintegration
of the raw materials are not sufficiently perfect, in which case free lime will assert itself White
spots in the latter case can be detected with a magnifying glass. If the expansion is due to an
excess of lime, the cement must be looked upon as dangerous. If, on the other hand, the cement
contracts, it is either overclayed or underburnt, and will be a quick-setting and weak cement. The
contraction in the bottle is best shown by pouring a little coloured water into it. Pats are also
made to test the soundness and colour of the cement, being immersed in water like the briquettes.

Portland Cement — Air-Slaking. ^i

If after a time the\- show flaws or cracks on their edges, the cement should be looked upon with
suspicion ; but as the cracks do not in some cases occur for several weeks after immersion, this test
is impracticable when the cement is required for immediate use.

Exi'AN'SKJN. — The expansion and contraction of Portland cement due to temperature is
greater than that caused by mere hardening. Mr Grant gives the following inferences: — (i) All
cements expand more or less when hardening in water ; (2; The expansion of good cement is so
slight that in practice it need hardly be taken into consideration ; (3) It is greatest when the
increase of strength is most active ; ( ^) It diminishes in proportion to the addition of sand ; (•,) It
is greatest with new cements, and least with that which has been kept in stock ; (6) It is increased
by the addition of gypsum ; {-j) It is greatest with over-limed or lightly burnt cements, and that all
cements contract when drying and expand on being put into water.

Adhesion. — A number of experiments for testing the adhesive strength of Portland cement
carried out b}- Mr Mann showed that the adhesive strength did not bear a uniform relation to the
tensile or cohesive strength, but varied from about i to 5 to i to 9 in the 7 days' tests, and
from I to 3 to I to 5 in the 28 da\-s' tests, the adhesive strength increasing more rapidly than the
cohesive in the 21 days which elapsed between the two tests. The average adhesive strength of
neat Portland cement is about 80 lbs. and 90 lbs. per square inch at 28 days. The tests in the
first series of experiments were made by tearing apart small pieces of sawn close-grained limestone
which had been joined with cement, and the second series with cement bedded between pieces of
sawn close-grained limestone.

Air-Sl.\KIXG. — Air-slaking and cooling plaj's an important part in the ultimate success of
Portland cement when used for plastering purposes, especially for facades. There is a consensus of
opinion among manufacturers and users, on the imperative necessity of dealing with the free lime,
and rendering it innocuous b\- air-slaking, previous to using the cement. The presence of free lime
can be detected by emptying the contents of a sack on a floor, and after a few days' exposure
closely examining it. It will then be found fissured all over with seams and cracks, .showing
unmistakably the disruptive effects.

The following description of a process whereby the free lime in Portland cement is rendered
entirely innocuous, is an e.xtract from a paper on " Limes and Cement," by Mr A. M'Ara, of
Glasgow : " The cement is first hoisted to an upper floor of the store, the sacks emptied, and
contents bulked, after which the cement is gradual!}- fed into a receiver, from which it is made
to fall down a c}linder or trunk, where, by a particular arrangement, it is caught at frequent
intervals on a series of perforated shelves, constructed in a special manner, so as to thoroughly
open up the body of the cement and delay its passage, while all the time a constant blast of cold
air is directed upon every particle from a perforated pipe through which a current of cold air
is forced by a fan driven by steam-power. The cement is subjected to this aerating process
during the whole time of its passage from the recei\er until it falls on the floor, where it is allowed
to lie for some time in this aerated condition to ensure the full effect of the process. The process
of maturing is much facilitated b\- the addition of a small percentage of finely pulverised carbonate
of lime, and a decided improvement effected thereb\-, the carbonate having a marked influence in
the ' setting' of free lime, which it is proved exists more or less in all Portland cements."

The ground carbonate contains always a certain amount of moisture in which a proportion of
the carbonate and bicarbonate of lime exist in the soluble state. The extreme avidity of the free
lime for water causes it immediately to absorb this moisture, and in doing so it slakes, thereby losing
its power for e\il ; and not onl\- so, but becoming to a slight extent hydraulic b\- the absorption

64 Plastering — Plain ami Pccorafive.

of carbonic acid from the bicarbonate in solution. I am also inclined to think that when watL-r
is added in makini; u)) mortar or concrete, a further absorption of carbonic acid occurs, aided by
the heat which, to some extent, accompanies the process of slakint;;. That some action of this sort
occurs is perfectly certain, otherwise the addition of a percentaijc of carbonate (jf lime would
weaken the cement exactly in the same way as so much sand added ; but after a long scries of
careful experiments on the cements of many manufactures, I have found tlu- \cry reverse to be
the fact, and instead of any weakening, there is a percejitiblc gain in strength. Having found
these eflccts from the application of carbonate to Portland cement, I searched some of the
recognised authorities on limes and cements, antl found much to confirm me in the adoption of
the process. Burnell says: "Broken limestone appears to add ver_\- much to the ciualities of
concrete betons and mortars. Very probab!)- this may be attributed to the affinity between the
molecules of the already formed carbonate of lime and that which is in process of formati<jn. The
new crystals may group themselves more easily about bodies whose form is similar to the one
they are them.selves to assume, or possibly there may be a tendency in the chemical elements to
arrive at a state of equilibrium, and the carbonate of lime ma\- therefore be supposed to part with
a certain portion of its carbonic acid." Burnell also mentions a discovery by a Mr Westmacott,
which formed the subject of a patent : — With a \icw to augmenting the resistance of the rendering
coats of plaster that are executed in lime, b\- the admixture of pounded limestone with that
material. This is in fact nothing more than the ap|)lication of the principle mentioned in the
text where the tendenc)- of the lime to crystallise around a gangue of the same nature as it.self is
referred to, and the inference is drawn that the ]jre.sentation of the cr>'stallised form of carbonate
of lime would be fav'ourable to the solidification of the mass of concrete betons cjr mortars.

It is to be observed that Mr Westmacott mi.xes with the chalk lime that he employs con-
siderable quantities of pounded chalk, or of some equally common description of stone that has a
base of carbonate of lime, and thus he obtains a mixture that is capable of setting with greater
rapidity. Vicat says : " To obtain mortars or cements capable of acquiring great hardness in
the o]jen air, and to resist rain and heat, we must combine (amongst other things) the powers of
hard calcareous minerals ; " and he also shows experiments with calcareous and granite sands,
which are in favour of the former. Henry Reid, C.K., says: "When in a moist state, lime would
probably dissolve a portion of any calcareous aggregate." Major-General Gillmore gives various
experiments to show that underburnt stones possess superior hydraulicity, and contain carbonic
acid ; and that o\erburnt stones, from which the carbonic acid is driven off, are less or more deprived
of "setting" power. Tomlinson says: "A ver\- intimate mixture of ([uicklime antl carbonate of
lime has feeble hydraulic properties ; and limestone gently heated, so that a large proportion
of it remains in the form of carbonate, slighth' h)-draulic. In the burning of rich limes, imperfectl>'
burned fragments are alwaj's found which have this character, and it appears to be due to the
formation of a definite compound of carbonate of lime and h)Tlrate of lime." " Portland cement
is different from all other hydraulic limes and cements, in respect that the high temperature
required in the kilns to effect the chemical combination of the lime with the silica and alumina,
drives off" nearly, though not quite, all the carbonic acid gas, and any particles of lime remaining
uncombined, as is always the case to some extent, have been deprived o{ all Indraulic or 'setting'
properties, and remain in the cement as so much quicklime ; w-hereas, in all natural cements and
hydraulic limes, there is left, after calcination, carbonic acid to the extent of from 6 to 8 per cent."

In the analysis of the famous hydraulic lime of Theil, in France, carbonic acid is present to
the extent of about 8 per cent. I would further call attention to the fact, demonstrated by

Magnesia in Portland Cement. 65

analysis, that when cement is laid out to air-slake by the method usually adopted on large
contracts, it increases in weight by the absorption of carbonic acid and moisture in the proportion
of two-thirds of the former to one of the latter. This is the same result as is effected by my process,
with this difference, that by my system the cement is acted upon equally throughout, while by
the usual method it is only the exposed surfaces that are properly purged of the free lime, unless
where frequentl)- turned over at great cost. Other authorities might be quoted, but perhaps
enough have been given for our purpose, and they go far to show that my air-slaking process, with
the addition of carbonate, is based on sound principles, and fitted to grapple with, and overcome, an
acknowledged difficulty and danger in the use of Portland cement.

The practice of aerating or air-slaking cement is only done to remedy as far as possible the
results of careless or imperfect manufacture. Aeration is unnecessary for a j^erfecth' burnt and
mixed cement, but in the present imperfect method of manufacturing it is advisable that it be
adopted. To avoid the very common danger of swelling and blowing, it is usual in well-
regulated firms of contractors and plasterers to open the cement bags when delivered on the works,
and to empty their contents on to a dry wood floor and leave the contents exposed from seven to
twenty-one days. The process is further hastened b}- frequently turning the cement up with a
long rake to allow the air to reach the cement at the bottom. The cement on the floor should not
be more than one foot deep. The dry cement swells under this treatment from the hydration of the
particles of caustic lime. Care should be taken that no damp gets at the cement, and that the
air-slaking is not too long. The cement can be tested by gauging a portion and putting it
in a glass bottle. If in expanding it does not burst the bottle, it is fit for use. Portland cement
should be used before it is six months old, after that period it begins to deteriorate in strength and
setting powers. If it is protected from atmospheric influences, it will keep better and longer.

Magne.SI.\ in Portland Cement. — Magnesia in Portland cement has a curious effect,
especially if the proportion is high. It acts as an inert substance while the rest of the cement sets.
After a time the magnesia begins to hydrate, and sets verj' hard ; but this process is attended with
a considerable augmentation of volume, which destroys the structure iri which the phenomenon
occurs.

The following opinions of several authorities on the use of magnesia, soda, and salts in
combination with Portland cement, as used in one of my patents, is taken from a series of articles
on "Artificial Stones," which appeared in TJic Builder : — "Wilkes and Millar's decorative fibrous
metallic compound, patented in 1885, is formed of a mi.xture of powdered slag, brick-dust, pumice,
slag-wool, and Portland cement, moistened in solution of chloride of magnesium (or bitternc water),
carbonates of soda, and ammonia and caustic soda. The caustic soda and carbonate would cause
the formation of a portion of h}-drate and carbonate of magnesium, which, uniting with undecom-
posed chloride, would form the desired oxychloride. The addition here of an ammonium salt
seems at first sight of doubtful utility, as such compounds tend to (prevent the precipitation of
magnesium compounds, yet it may in virtue of this very propertj' be useful in preventing the too
rapid setting of the mixture, and owing to its volatile character, its expulsion, and the removal of
its retarding influence, would only be a matter of time and temperature. To impart strength and
flexibilit)- to the compound, the inventors mould it on wire or perforated metal work, or incorporate
it with tow. In some cases the soluble silicate and chloride of calcium treatment is applied, and
the stone finallj- washed with a solution of bichromate of pota.sh. Erdmenger states that magnesia
calcined at a low temiierature possesses the property when added to Portland cement of rendering
the latter more durable and better able to withstand the influence of the .salts of sea-water. The

66 Plastering — Plain and Decorative.

temperature of calcination has an important practical bearing upon this matter, for M. Lechartier
has pointed out that magnesia calcined at a high temperature has a most evil effect upon the dura-
bility <if I'Drtland cement, in consequence of its peculiar jjroperty, first noticed by St Clair Deville,
of uniting with water to form a hard hydrate, an increase of volume at the same time taking place.
This hydration, in the case of over-calcined magnesia, only takes place after a prolonged contact
with water, so that in some cases investigated by Lechartier (the cement having been made from
dolomitic marl, and which seemed to set very hard, and to be in all respects most satisfactor\j,
in a year or two disruption of the cement and destruction of buildings in which it had been
employed showed the practical effect of a neglect of Deville's observation. The indurating effect
of ammonium salts is disputed bj- some, but they are nevertheless used by several patentees in
artificial stone."

I^I.VGNESIA Cemknt. — A new method of treating magnesia has been recently invented. It
was formerly merely calcined and made up with water. Now the calcined magnesia is careful!)-
slaked, and is subsequently exposed to the action of carbonic acid gas, much in the same \\a\- that
plasterers have been in the habit of drying and hardening newlj- plastered rooms by burning coke
in the clo.sed rooms so as to liberate carbonic acid gas. The new substance is used as a cementing
agent, and when mixed with marble dust an artificial dolomite is obtained.

Effects of Age ox Cement. — Practical experiments full\- determine the effects of age on
Portland cement in a dry state. The cement gradually absorbs moisture and carbonic acid from
the atmos|jhere, and chemical changes occur in it analogous to those which take place when it is
gauged for use. The longer the cement is kept, the greater will be the extent of these changes,
and consequently the greater the extent of the deterioration. Ultimately a cement may become
quite useless. A certain amount of air-slaking, however, is necessarj- and beneficial to some
qualities of Portland cement. These latter, especialh- when under-burnt, verj- frequcntlj- contain
an excess of free caustic lime, which causes the cement to swell very considerabl)- if used
immediately after being made. This swelling causes the work to blow, and otherwise spoils it.

To Set Quick. — Various materials and methods have been used to hasten the setting of
Portland cement, more especially for cast work and for paving. A common method for cast work
is to place the newl\- filled moulds before a fire. This should never be done, as the heat abstracts
the moisture which is necessary for the proper setting of the material, thus causing the work to
become more or less friable. Drj- heat will dry the cement, but that is a very different thing from
causing it to set. Moist heat may be used ad\antageously ; it hastens the setting and also the
hardening of cement. Urine is sometimes used to ha.sten the setting, but besides being offensive,
it is liable to cause an efflorescence to arise on the surface. Warm water has also been used for a
similar purpose, but the effects are often disappointing, unless special care is taken to regulate the
temperature. When used for jellj- moulds it acts disastrously. Soda dissolved in water, and then
mixed with the gauging water, is also frequenth- u.sed to hasten the setting of Portland cement
casts. Soda quicklj- obtains the desired effect, but in man)- instances it causes the work to blow
and crack. These evils ma)- be partly corrected by first heating or roasting the soda on a hot
plate before dissolving in hot water, and then allowing the solution to thoroughl)- cool, anfl
afterwards passing it through a ver)- fine-meshed sie-v-e or a muslin bag to free it from sediment.
It is then mixed with the gauging water, and regulated precisel)- in the same wa)- as used for size
water and plaster, and then exposing the solution to the air for not less than three months before
using it. Portland cement mixed with a solution of calcium chloride rapidl)- acquires great hardness.
Setting begins in three or four minutes, and is attended with a rise of temperature that may attain

Increase in Strength of fort land Cement.

158' F'ahrenheit. Cement mixed with calcium softens if immediately put in water, but after being
air-dried for eight or ten da\-s may be immersed without detriment to its cohesion and hardness.
Ordinary damf) air has no intluence u|:)on the mixture. When great hardness and quick setting is
required, the cement maj' be used neat, but for general purjioses cement and sharjj sand in equal
proportions may be used.

Influence of Light on Portland Cement. — The influence of h'ght on cement has been
proved by dividing a quantity of newly made cement into 3 parts, exposing part .A to the air and
full light, B to the air and diffused light, C in darkness and excluded from the air. After six
months A made a weak mortar ?jy absorbing 38J per cent, of its weight of water, and was
crumb!}-. B with 33^ per cent, of water made a mortar which was too adhesive to the trowel, and
it did not )-ield any of its water. C with ^i\ per cent, of water made an excellent mortar, easily
gauged, and it relinquished some of its water. After setting for twenty-eight days the relative
strengths were — A, 3 ; B, 37.9 ; C, 44.6. These tests pro\-e that cement should be covered over
with boards, or kept in bags until required for use.

Increase in Strength after being Gauged. — Portland cement increases in strength
after having been gauged. The following table, compiled from experiments made by Mr Grant in
1865, will show the increase. The test blocks were 2\ inches square at the neck, and were kept in
water from the time of making to the time of testing.

Table V. — Increa.se in Strength of Portland Cement after being Gauged.

.■\ge.

Neat Cement.

I of Cement to 1 of Sand.

.'\verage Breaking Test of

Average IJreaking Test of

10 Experiments.

7 days.

817 lbs.

353 lbs.

3 months.

1.055 >,

547 „

6 „

i,i7'i „

640 „

9 „

1,219 ,.

692 „

'•229 „

716 „

2 years

>>324 .,

790 „

4 „

',312 „

818 „

6 „

>,3o8 „

S19 .,

7 „

1,327 „

863 „

These tests show that neat cement gradually increases in strength for two years, but that
after the second year the increase is somewhat less. Cement with sand appears, however, to have
continued to increase for seven years.

Fire-Resisting Propektie.s. — It is often claimed that plaster resists the influence of fire
more than an)- other cement, but from experiments made to ascertain its fire-resisting properties
ii has no advantage over good Portland cement.

Mr H. Lockwood made several blocks of concrete, some consisting of plaster and broken

f/dsfirij/g- /'/dill and /krorativc.

retorts (?,), and others of rortland cement and burnt shale (|). At the age of six weeks the\-
were subjected to intense heat for i hour and 45 minutes, after which they were plunged into
water for 8 minutes, and when taken out those made of g)-psum were completelj- disintegrated,
while it took considerable force applied with a sledge-hammer to break those composed of Portland
cement.

The following table (from The Builder) shows the results of experiments carried out by Mr
J. G. Webster to ascertain the fire-resisting jjroperties of various kinds of concrete: —

TaI'.I.L: \'1.— SUMMAkV ok TLSTS as to THL FlKli-KESISTIM. PKiiri:Kril> 1)1 \AR10US

COXCRliTES.

lire.\king Weigh

per square inch.

Average Loss

No.

Materials in Concrete Briquclie*.

Proportions

of
Ingredients.

Average
Weight per
cubic foot.

pfr cent, of

Original

Slrcnulh after

Heating and

Quenching.

At Temp, of
60° Fahr.

After being
Heated and
Quenched.

lbs.

l'ortl.inci cement ....

Neat

124.6

554-6

117.2

78.8

,, and sand

I to 1

120.9

448

79-2

' - 3

III. 2

100.8

i8.7

81.4

T) 11 i» " " "

' .. 5

109.7

74.6

79-8

„ „ iron furnace slag -

1 n 4

163.08

loS. 1

23.06

78.6

„ „ fire-brick

1 - 4

95-04

84-4

30.5

63.8

„ „ pumice-stone

I ., 4

64.8

94-6

38.3

59-5

„ „ coke-breeze

I „ 4

71.65

C9.9

30.06

56.9

Plaster of Paris and fire-brick

> „ 4

89.6

66.8

10.3

84.5

„ „ pumice-stone

I „ 4

55.6

57-4

3-4

94.07

„ „ furnace slag

1 "^

.48

223.6

4.7

97-8

„ „ fire-brick ■

I 2

106.9

167.5

■5-7

90.6

These tests were undoubtedly severe, for concrete can hardly e\er in actual construction be
heated to such a degree and quenched so quickl)-, but they prove that Portland cement resists fire
better than plaster does.

Setting. — The chemistrj- of setting is rather vague. It has not been clearly demonstrated
what part each constituent of Portland cement plays in its setting. That the lime and silica are
the greatest factors is certain, but the action of the rest is rather uncertain. Knapp, a German
authority, inclines to the opinion that iron and alumina are only of indirect service, but that soda
and potash, which combine with silicic acid to form silicates of soda and potash, and are in that
form soluble in water, act as " transferrers of silicic acid to the lime." The time of setting of
different Portland cements varies according to the class of manufacture, their freshness or staleness,
and the mode of gauging. The time ma\' therefore vary from ten minutes to ten hours. Slow-
setting cements are preferable to quick-setting ones. Before beginning large sections of work the

The Hardening of Portland Cement. 69

time of setting should be tested and noted. This may be determined by gauging two or more pats
of neat cement and placing them in the air. If a pat can be indented by a moderate pressure of
the thumb nail at the end of two hours, it may be considered slow-setting. The " initial set," that
is, when it commences to stiffen, and the " set hard," should be timed. The initial set is noteworthy,
as it indicates the limit of time within which the cement ought to be laid after being gauged. The
addition of sulphuric acid or 2 per cent, of plaster retards the setting, but accelerates the
maximum strength.

Hardening. — The hardening or induration of Portland cement is as yet somewhat imperfectly
understood. V'arious theories have been advanced as to the hardening or induration of Portland
cement, but the practical causes are somewhat obscure. Knapp, a German authority, states that a
portion of the calcium oxide formed during calcination reacts upon the clay and conv-erts it into
a compound easily decomposed by acids. This compound and the excess of calcium oxide, when
water is added, react upon each other in such a manner as to produce a solid stone-like " silicate."
]\Ir Guthrie, Demonstrator of Chemistry at the University of Sydney, considers that at a com-
paratively low temperature the lime is converted into silicate of lime, and at a high temperature
induces the formation in addition to this of aluminate of lime, and finally of a double silicate of
alumina and lime. This double silicate of lime, and also the aluminate of lime, on the addition of
water, form h}-drated silicates and aluminates, which set by crystallising. The hardness and non-
absorptive qualities of Portland cement, according to another authorit)-, are due to its structure
being laminated., while that of other cements is globular, the result being that the Portland cement
particles touch at all points, thus admitting of no interstices for the lodgment of water, while the
reverse condition would be the case with cements where the particles were globular. The
hardening results from the formation of a chemical compound of lime and silica. If Portland
cement is made up with a strong solution of carbonate of ammonia no hardening takes place, but
if some hj-drate of lime be added the cement hardens.

Specifications. — There seems to be a free trade in the form of specifications for Portland
cement in England, as most engineers specify the strength, fineness, &c., of the cement according
to their own particular fancy or individual requirements. In Germany and Austria there are
standard rules for the guidance of cement users. The German standard regulations, among other
things, require that not more than lo per cent, of the cement shall remain on a sieve with 5,006
meshes per square inch (the thickness of the wire being equal to half the width of the meshes),
and that cement requiring more than half an hour to set made into briquettes with 3 parts (by
weight) of standard sand, and tested after being one day in air and twenty-seven daj-s in water, shall
have a tensile strength of 227.5 It)s. per square inch, and a compressive strength of 2,275 't)S. per
square inch, and that a thin pat of neat cement, which after setting on glass is placed in water,
shall not crack at the edges. Mr Grant gives various intricate specifications for Portland cement,
the latest being based on the German standard regulations then in force. He suggested : — i. The
Portland cement, before being used, to stand 300 lbs. tensile strain per square inch seven days after
gauging ; the average of not less than three breakings to be taken. 2. The cement to be finely ground,
leaving a residue not exceeding 10 per cent, after passing a sieve of 2,500 holes to the square inch.
3. Pat samples \ inch thick, made at frequent intervals, and immersed in water within one hour, to
show no cracks from expansion within forty-eight hours of gauging. He thinks the weight per bushel
is valueless. M. de Michele suggests another form of specification. Conditions as follows : —
" Pats i inch thick in water, absolutely sound at seven days. Tensile strength, 400 lbs. per square
inch at seven da)-s. Fineness, 10 per cent, residue on a 50 sieve. The pats to be gauged on glass

Plastcriiia: — Plain and Decorative.

immersed in water immcdiatel}', and left there for the whole period. One pat to each three
briquettes. The test briquettes to be gauged by a skilled man, with any quantity of water, in any
way he likes. The average of three to be taken, which shall represent about lOO tons. The strain to
be applied as quickly as possible. The sieve to have 2,500 holes per square inch, and to be of wire
xnrAh of an inch in diameter. Shaking to be continued until nothing ground in the mill passes."

Some manufacturers issue specifications of their cement. The following is a fair specimen : —
Weight — The cement to weigh not less than 1 12 lbs. per striking bushel. I""ineness — To be ground
so that no more than 5 per cent, residue shall be left on a sieve having 2,500 meshes to the square
inch. Tensile strength — The briquettes at seven days (during si.x of which they shall be immersed
in water) shall not break at less than 350 lbs. on the square inch. It will be noticed that these
specifications contain no test for soundness or adhesive strength, both of which are most important
factors for most concrete purposes and especiall)' for plaster work.

Ri:l.\tivi-: Finlxks.s .xnd Co.st of Poktl.vni) Cement. — Portland cement is .so largely u.sed
at the present time in building work of every description that it might have been thought that
u.sers would have taken the greatest care to obtain the very best quality, not only from the desire
to carry out the work satisfactorily, but because a reall)- high-class cement is much more economical
to use than one of inferior quality, and is therefore actually cheaper to bu)- than an apparently
low-priced article. A good many users, however, are content to buy a cement bearing some well-
known brand, feeling assured from previous e.xperience that such a cement will give satisfactory
results. So much attention has of late years been devoted to the manufacture that, as regards the
mixing of the raw materials in their due proportions and the proper calcination of the mi.xture so
obtained, one brand ma)' be said to be very much like another ; and provided the works are
suitably designed, and the various details of the manufacture carried out with care, it may be
accepted as a general rule that a com|jaratively unknown make of cement is in the.se respects equal
to the best known and highest brand in the market. The true test of quality is not to be found
in the brand, but in the fineness to which the cement is ground, always provided, of course, that
the materials are carefully selected, and the various stages of manufacture properly carried out.

The fineness to which Portland cement is ground is an important factor in its cost and sub-
sequent value. Cement experts show a singular unanimity in declaring that, ceteris paribus, a
finely ground cement is far superior to one that is but coarsely or even but moderately finely
ground. The reason for this fact is twofold. In the first place, a finely ground cement will spread
itself over and round the aggregate of concrete better than a coarsely ground cement. Good
concrete can only be obtained when every particle of the aggregate is thoroughly covered by and
incorporated with the cement, and it is obvious that the aggregate can be more completely covered
and surrounded by a cement as fine as flour than by a cement containing a large proportion of
coarse and gritty particles.

.Again, mouldings and fine finished or trowelled surfaces are more readily and easily formed
with a finely ground cement than w ith one that is coarsely ground. But the second and more
important reason is this, it is only the fine portion of the cement (technically known as the
"flour") that has any cementitious or binding properties, and hence a coarse cement contains a
large proportion of matter that is absolutel)- u.seless. This can be easily proved bj- the following
simple test : — Take a small quantity of cement and sift it through a sieve of, say, 2,500 meshes to
the square inch (commonly known as a 50-mesh sieve, i.e., having 50 holes to the lineal inch).
The portion that passes through the sieve, when gauged with water in the usual way, will be found
to set hard, while the residue, or portion retained by the wires, if gauged, will never properly set.

Relative Fineness and Cost of Portland Cement. 7i

If, ho\ve\ci-, the residue were ground up fine enough to pass through the sieve, i.e., ground to the
same degree of fineness as the portion already sifted through the sieve, it would be found to set
as readily and as hard as the first portion. Ordinar\' cements, such as are commonly supplied
when no particular degree of fineness is specified, are ground to leave a residue of from lo to 15
per cent, on a 50-mesh sie\e. In other words, the residue being, as shown above, absolutely use-
less, they are for all practical purposes adulterated 10 to 15 per cent. And although the adul-
terant gives the same chemical anal)-sis as the true cement, j-et it possesses no more value as a
cement than so much sand. But although a user may be convinced that the foregoing remarks are
true, and that a finely ground cement is cheaper in theory than a coarse cement, yet he wishes to
be quite certain that in actual practice it will give equally good results. On this point the
superiority of fine cement is e\en more striking. Mr H. K. G. Bamber, F.C.S., in a paper which
ap]jeared in The Builder, gives a series of exhaustive tests made with a cement leaving 1 5 per cent.
residue on a 50-mesh sieve, and one leaving no residue at all on the same sieve. Each cement was
gauged neat and tested at seven and fourteen days. Briquettes (i-inch section in each case^
gave the following results : — Coarse cement 440 lbs., fine cement 467 lbs., both at seven days ; and
at fourteen days the results were 530 lbs. for the coarse cement, and 561 lbs. for the fine cement.

A more useful test is when cement is gauged with sand, as the strength of the concrete made
from it can be more correctly estimated than b)" tests of neat cement. Briquettes of the same
cements were gauged in the proportion of 3 parts sand to i part cement, and were tested at twenty-
eight days, gi\ing the following results : — Coarse cement 154 lbs. per square inch, fine cement 212
lbs. per square inch, an increase in favour of the fine cement of 37.66 per cent. That this increase
of strength is a true and not mereh- an apparent increase, is shown b\- further tests in which smaller
quantities of the fine cement were used with the same amount of sand, as follows : — Coarse cement
(3 of sand to i of cement) 154 lbs. ; fine cement (3 of sand to .75 of cement, equal to 4 of sand to i
of cement; 158 lbs., increase 2.6 per cent. ; fine cement (3 of sand to .50 of cement, equal to 6 of
sand to i of cement) 145 lbs., decrease 5.8 per cent. These tests show that with fine cement 25
per cent, less cement can be used and give a stronger mixture than that obtained from the full
quantity of coarse cement, and that half the quantity of fine cement will only show a slight decrea.se
of strength as compared with a mixture in which double the quantitj- of coarse cement is u.sed.
The cause of this superiority is, as stated above, that the "residue" has no setting or binding
qualities whatever, a statement which can further be proved by the fact that if the "residue" is
removed and replaced b)- an equal quantity of sand, the mixture of cement and sand would stand
the same test and be of the same strength as the original cement gauged up neat with the residue
left in it.

The foregoing proves conclusively that when a contractor buj-s an ordinary cement, one con-
taining say 15 per cent, residue on a 50-mesh sieve, he bu\-s an article that does not contain more
than 85 per cent, true cement, and is therefore practically adulterated 15 per cent., and for this 15
per cent, of useless matter he pa\-s the same jjrice as if it were good cement. In fact, he buj'S so
much sand at cement prices. And, further, when this 15 per cent, of inert matter is ground up, the
cement is not merely 1 5 per cent, better, but, as the above tests prove, it is 37.66 stronger. The
real amount of useless matter is much greater than i 5 per cent., for a cement that would leave 1 5
per cent, residue on a 50-mesh sieve would leave a greater residue on a finer sieve. The finer the
sieve, the greater amount of residue or inert matter, and the residue on a fine sieve is practicall)- as
useless as that on a coarse. To put it another waj- — a fineh" ground cement (no residue on a 50-
mesh sieve) will go over 37 per cent, further than a coarse cement leaving a residue of 15 per cent.

-2 Plastering — Plain and Decorative.

on the same sieve ; that is to say, 63 tons of the fine cement will give as good results as 100 tons
of the coarse. These are facts that should be carefully remembered when buying cement, as they
show that the lowest price cement is not necessarilj' the cheapest. Buyers should always compare
degrees of fineness as well as prices, and if that were done they would demand a finel>- ground
cement. One of the reasons whj" this practice has not hitherto prevailed to any extent is, perhaps,
that finely ground cement has been difficult to obtain. Manufacturers do not, as a rule, care to
grind their cement finely because of the e.xtra wear and tear of millstones and machinery it entails ;
or if they do, thej- invariably have to charge an extra price to cover the increased expense. It is
said that the difference in price between a cement of which 70 per cent, passed a sieve with 14,400
meshes per .square inch, and one of which 88 per cent, passed through the same sieve, was 3s. 8d.
per barrel, and it was found much more economical to use the latter. Francis & Co., Hilton,
Anderson, Hrooks & Co., both of London, and the Dartford Portland Cement Company, make
finely ground Portland cement a specialty. They can supply a cement that will pass not less than
95 to 97 per cent, through a 76-mesh sieve, viz., one having 5,776 holes to the square inch. This
is equal to less than i per cent, residue on a 50-mesh sieve, and is 5 per cent, finer on a 76-mesh
sieve than the fine cement used in the above-mentioned comparati\e tests. The foregoing tends
to prove that the fineness to which l^ortland cement is ground should regulate its price.

The Portland Cement Trade. — The invention of Portland cement, as we have already
seen, is of comparatively recent date. At first the demand was so small that in 1850 there were
only four factories in operation, producing about 70,000 tons. There are now nearly forty factories,
producing 2,000,000 tons per year. The manufacture of Portland cement was first introduced into
Germany in 1S52, and there are now sixty factories, producing 1,250,000 tons. A year later a
factory was started in France, and there is now an annual production of 350,000 tons. The
French Cement Company's factory at Boulogne is the largest in the world, and produces 135,000
tons per year. In Russia, the first factory was established in 1S57, and there are now eight
factories, producing 155,000 tons per year. In Belgium there are four factories, producing 136,000
tons. In Denmark, Norway, and Sweden there are ten factories, producing 135,000 tons. Portland
cement was first imported into America in 1S65, and there are now 500,000 tons per year imported
mainly from England and Germany. The American production, owing to the unfavourable
nature of the raw materials, is at present very small. In China there is only one factory, which
produces 9,500 tons per annum. In Italy there are no Portland cement works, but there is a
natural cement made, which is very similar to Portland cement. In Australia the manufacture of
Portland cement is as yet of a limited nature. The South Australian Portland Cement Company
states that briquettes of their Portland cement have attained a tensile strength of 950 lbs. to the
inch — the greatest strength on record.

Slag Cement. — The history of waste products is extremely instructive. Lord Palmerston
declared that " dung was only gold in the wrong place." A striking example of the utilisation of
waste products is found in the manufacture of cement from iron furnace slag. Another example is
the use of crushed slag as an aggregate for fine concrete, and slate waste for the manufacture of
plaster, cement, and artificial stone, as introduced by the author. All slags are not fitted for con-
version into cement, as some do not contain the necessary ingredients in suitable proportions ;
while some others contain an excess of sulphur, which is dangerous to the cement made from it.

Manufacture.— In 1850 a patent was obtained by Mr J. Gibbs for the manufacture of
mortar by mixing slag with lime. In i860, Mr G. Parry proposed a plan of subjecting the melted
slag (as it runs from the iron furnaces) to a powerful jet of air or steam, which produces slag wool,

Slag and Roman Cements. 71

or silicate cotton, which is now used for a varietj- of purposes. Mr C. Wood, of Middlesborough,
introduced further improvements in reducing slag to slag sand. The slag sand is ground with 5
per cent, of lime, and used as a mortar. It sets within twenty-four hours of being made. Messrs
Bone & Walters patented a process for converting slag sand into cement. The slag is screened, and
about 25 per cent, (by weight) of slaked lime is also passed through a fine sieve and added.
The mi.xture is thoroughlj- amalgamated, and ground together through a machine called a
" homogeniser." This consists of a revolving drum, partly filled with metal balls about i inch in
diameter. In this drum the slag and lime particles are acted upon hy the continuous blows of the
balls, and are crushed to a powder sufficiently fine to pass through a sieve with 32,000 holes per
square inch. These molecules are mechanically brought into the closest possible contact, thus
producing a " floury-silky " powder. It is asserted that this treatment would improve Portland
cement made in the ordinary way. The process of " homogenising," as compared with simple
mixing, effects a vast improvement in the quality of the slag cement, its tensile and compressive
strength being thereby almost doubled. The average weight is about 90 lbs. per bushel. Specific
gravity is 2.73 against 3.10 for Portland.

FiXENES-S. — Slag cement is generally far finer ground than Portland cement. A sample of
slag cement tested at Berlin left no residue at all on a sieve with 1,160 meshes to the square inch,
only I per cent, on one with 3,870, 5 per cent, on one with 5,800, and 14 per cent, on one with
32,200 meshes.

Tensile Strength. — The following shows the tensile strength of slag cement as taken
at the Royal Testing Offices, Berlin : —

T.A.BLE \TI. — Tensile Strength of Sl.\g Cement.

.\t 7 days. lbs. .\t 23 da)*s, lbs.

per square inch. per square inch.

Slag cement, neat ------ 647 692

„ and sand i to 3 - - - - 427 509

COMPRESSn e Strength. — The average force required to crush briquettes of slag cement.
gauged with 3 parts of sand, is about 3,376 lbs. per square inch at 7 da\-s, and 4.296 lbs. at 28
days. Briquettes of Portland cement and sand similarly tested have an average strength of 4,822
lbs. at 28 da}-s, or 12 per cent, more than slag cement ones.

Uses. — Slag cement gauged neat is more plastic and works " fatter " than Portland cement.
It requires from two to five hours to set. When set it has a fine white colour. It is well adapted
for cast work, and may be usefully employed for plastering. The great adhesive strength,
combined with its unequalled fire-resisting properties (exceeding those of both plaster and
Portland cement), recommend its use for concrete stairs, floors, and roofs. It has been emploj-ed in
the construction of the harbours and docks at Skinningrove, Yorkshire.

Basic Sl.\g is ground at Bilston for fertilising purposes. This slag is so fine that it will pass
through a mesh of lo.oco holes to the square inch. It is composed of 40 per cent, of lime and
about 20 per cent, of phosphoric acid. This fine slag might be advantageously used for making
slabs and for general plastering purposes.

ROM.\x Cement. — A h\drau!ic cement was patented b)' Mr Parker, of London, in 1796
which he called Roman cement (probablj- from its dark colour, resembling that of mortar found
in Roman buildings). It is made from the septaria nodules of the London Cla\- formation found
in the Isle of Sheppey. The septaria of Harwich also produced a cement of the same nature. A

74 Plastering — Plant and Decorative.

similar material was discovered in 1802 at Boulogne. It is also to be found in the Bay of
Weymouth, Calderwood in Scotland, in Yorkshire, Burgund)', and Russia. It takes the form of
detached nodules of a dark-coloured argillaceous limestone, with veins filled with calcareous spar.
Its colour is sometimes blue, sometimes brown or red, owing to the presence of o.xide of iron.
The Shcppey stone usually contains 55 parts of lime, 38 of clay, and 7 of iron ; the Harwich stone
47 parts of clay, 49 of carbonate of lime, and 3 of oxide of iron. Before being burnt, the stone is of
a fine close grain, of a past)- appearance, and the surfaces of fracture are greasy to the touch. The
kilns used are worked on the intermittent sj-stem. It is afterwards ground to a fine powder,
the quality of the cement depending upon the qualit\- of the stone used, and the care taken in
burning.

During calcination the stone loses about one-third of its weight, and when ground is of a
dark brown colour. Roman cement is an admirable material where great rapidit\- in setting is
required, and is very useful in repairing jobs. Another advantage is tliat it will receive paint
almost as soon as finished, while Portland cement ought not to be painted until thoroughly dry —
frequentlj- the work of several months. It is sometimes gauged with Portland cement in making
casts in order to accelerate the setting. Its quick-setting properties necessitate a great deal of
skill and attention on the part of the workman, and it must be applied as soon as gauged.

Roman cement weighs from 70 lbs. to So lbs. per imperial bushel, and has a specific gravity
of 0.85 to 1.00. It will not carry more than 2 parts of sand or other aggregate. Its use at the
present day is very limited. It was, however, at one time extensively employed for external and
internal plastering in London. In the Great Exhibition of 185 1 experiments were made with
Roman and Portland cement, and it was conceded that the former possessed only about one-third
the strength of the latter. A superior class of Roman cement is made by Mr A. M'Ara, of
Glasgow, good materials being foimd at Calder Glen, Orchard, and Barrhead.

SllElTEV Cement. — Sheppey cement is very similar to Roman, but is of a better quality.
The septaria of Sheppey, from whence it takes its name, surpasses others for making a good
cement, probably from the effect of the action of the waves in reducing the less hard parts
of the stone, and freeing the original nucleus of the septaria from an excess of claj-ey matter.
Its quick-setting properties recommend its use for cast work, also for plastering in some
situations.

MeI)IN.\ Ce.menT. — Medina cement is much of the same class as Roman, and is made from
the best qualities of septaria in the Isle of Sheppey and Isle of Wight. It sets a light brown
colour, and very rapidly — almost as soon as it leaves the trowel. It is stronger than Roman, and
may be taken at about half the strength of best Portland cement. Owing to its quick-setting
qualities it is often used for cast work.

Atkixsox'.s Cement. — A fourth variety of Roman cement is Atkinson's. It was formerly
used for external plastering, but as \\\^ Johns Stucco Cement, Metallic Cement, and others, it has
been practically superseded for all purposes by Portland cement.

Martin'.s Ce.menT. — Martin's cement was the first white cement of a reliable nature having
gypsum for its basis. This cement was invented by Richard Green Martin, of Lambeth, London,
in 1834. It consists of an admixture of alkali and acid with gypsum. According to the
specification, i lb. of strong alkali (pearl ash) is dissolved in i gallon of water, and then sulphuric
acid is added ; the gj-psum is soaked in this solution, then it is calcined and ground to a fine
powder. In 1840 Martin obtained a patent for an improved method of making the cement which
bears his name. Hydrochloric acid is sometimes added to prevent an alkaline reaction. The

Keens and Parian Cements. 75

cement is of a creamy colour, and sets very hard. It is chiefly used for walls, dados, and skirtings.
It works clean and freely; it can be painted or papered the day after being finished. There arc
three qualities — coarse, fine, and superfine.

Keen's Cement. — Keen's cement was patented in 1838 by J. D. Greenwood and K. W.
Keen. The first patent was for the manufacture of cement, and producing ornamental surfaces.
Mr Keen afterwards made a disclaimer for the ornamental surfaces, claiming the cement only.
Keen's cement is obtained by soaking the best kinds of plaster in a solution of i part of alum to
12 parts of water, at a temperature of 95 ; after three hours the mass is removed and dried. It is
then baked a second time to eliminate the water of combination, after which it is careful!}' ground.
It is manufactured in three qualities — coarse, fine, and superfine. The last is perfectl)- white. This
cement is capable of being worked to a very hard and beautiful surface, which takes a brilliant
polish. It is largely used for internal decorations, columns, and architraves, and also forms an
e.^tremely hard plaster for walls, skirtings, &c. It can be painted on or papered within a few hours
of being finished. When used for walls, the rendering coat should be formed of the coarse quality
of the same material or Portland cement.

Howe's Improved Keen's Cement. — This improved Keen's cement is prepared by a
particular combination of alkalies, and treatment, that, combined with the dense granular gypsum
used, give a thorough plastic material. According to tests carried out by H. Faija, this material
becomes extremely hard, and also shows no indications of efflorescence or other disfigurements of
any kind after being painted. The manufacturers recommend the following gauge and method for
working the improved cement. Gauge 3 parts of clean sharp sand to i of cement ; float the walls
to a good regular surface, and let them remain for three days ; in the meantime any mouldings or
skirtings can be run. The floated walls may be then finished with a coat of neat fine cement. When
the cement stiffens it should be laid down slightly at first, and as it becomes hard finish with a still
joint rule. For casting enrichments, the improved cement is gauged \er)- soft, and poured into the
mould ; then with a sponge press it into every part of the mould ; keep squeezing the water out of
the sponge, and the cement will be found getting stiff, consequent upon the sponge extracting the
water from it.

Parian Ce.ment. — Parian cement was patented in 1846, by J. Keating, a London scagliolist.
According to the specification the cement is made by dissolving 5 lbs. of borax (borate of soda) in
6 gallons of water, then dissolve 5 lbs. cream of tartar in 6 gallons of water, and mix together.
The gypsum stone or in form of plaster is then immersed in this solution. The mixture is
afterwards calcined and subsequently carefully ground. Parian cement is so called owing to its
likeness to the marble of that name. Parian cement works freer than either Keen's or Martin's.
Parian has greater tensile strength than Keen's or Martin's. Briquettes having a sectional area of
2\ inch at the end of 14 days give the following results: — Martin's, 580.7 ; Keen's, 585.S ; Parian,
642.3. Parian cement sets rather quick for general use, but it has the property of resetting after
being worked up a second time. It must not be supposed that this would be possible if the cement
had fairly hardened, but merely if it has become stiff, when it ma\- be made fit to use again b>- the
addition of water. It is excellent as a finishing coat on a floating of Portland cement, as a pre-
ventive of damp on walls, and for hospital walls on account of its non-porous nature, and the
smooth face which can be worked up, making the walls eas\- to wash. On account of the great
hardness which Parian cement attains, it is also used for work in exposed positions, such as beads,
arrises, skirtings, &c. It is also suitable for the manufacture of chimney-pieces, pedestals, &c.
It can be painted or papered almost as soon as finished. Coarse Parian for floating purposes can

"6 Plasteyiiig — Plain and Decorative.

be rendered more dense and hard by the addition of a solution of white china clay in the pro-
portion of 7 lbs. of clay to i cwt. of cement. The cement would require about 28 lbs. of water to
gauge it. A solution of white clay in lesser proportions can be used for setting purposes to render
the work closer in texture, and give a natural semi-polish.

RoiUNSOX'.s Cement. — Robinson's cement was patented in 1883. It is manufactured with a
basis of gypsum having an admixture of tincal (an imported material) and alum, in about the
proportion of 45 lbs. of tincal and 15 lbs. of alum to i ton of gypsum. The whole are finely
ground, and treated in a special manner. The gj-psum is nearly white, and of a very hard nature,
which is an advantage, as it gives greater strength to the cement when set. It is considered one of
the best fireproof materials in the market ; it forms a dense and hard surface. The cost is less
than Keen's or Parian, and rather more than ordinary plastering. Like all other cements and
lime.s, the sand that is mixed with it must be clean, dry, and sharp. The cement and sand are
mixed dry in a gauge box, sufficient water being added to gauge them. This cement must not be
knocked up a second time. Walls must be thoroughly brushed and wetted before laying on the
first coat, and laths should not be more than a quarter of an inch apart. The first coat is
scratched, and the second finishing coat can be laid on at once. This fini.^hing coat is generally
gauged in pails, and gauged thinner than ordinary .setting stuff. Allow the cement to soak a few
minutes before using. It is also used for cornices and for casting enrichments. Its non-absorbent
property is a sanitary desideratum. For setting fibrous plaster slabs, also the soffits and the
ceilings of concrete stairs and floors, it gives better results than gauged putty or setting stuff".
It is a good cement for repairing old or broken plaster, also for alterations and additions.
There is no waiting for each coat to dry ; the work can be finished in one operation, and be
painted, papered, or distempered nearly as soon as set. This cement is made in three qualities,
viz.: — \o. I, for finishing coat on walls or ceilings, whitewashing mouldings, castings, and tile
fixing ; it is pure white, and can be polished to a beautiful surface ; No. 2, for first coating, with
sand according to requirements. The proportion of sand varies, but 2 to i for ceilings and 3 to 1
for walls and partitions may be safely recommended for good work.

The following table (No. VIII) exemplifies the tensile strength of Robinson's cement as tested
by H. Faija in 1885. He tested its tensile strength both neat and when gauged with varying pro-
portions of sand, as well as its power of resistance to a crushing force, with the following results
per square inch : —

Tarle VIII.

Thr«days Seven da;s Twenty-eight

from gauging. | from gauging. gauging"

Neat cement broke at - - - - 497 549 784

One part cement to two parts sand broke at ... 459 525

One part cement to four parts sand broke at ... 297 331

Neat cement five weeks from gauging collapsed under a crushing force of 3,761 lbs. per cubic
inch.

Ad.amant. — Adamant cement was invented in America about a decade ago. It has a basis

Adamant Cement and Bassetf s Plaster. 77

of gypsum and sand ; fine sawdust enters largely into its composition. It also contains a small
proportion of dry glue, carbonate of soda, and borax. Adamant is gauged in shallow water-tight
boxes, holding about two bags each. It is gauged thin, then adding as much dry material as will
make it work freelj-. Xo more should be gauged than can be laid and finished in two hours.
The finished work never exceeds i inch thickness. Sawn laths are preferred for this material
I inch by \ inch, and nailed | inch apart. It is made in three qualities. Xo. 2, for floating ceilings
and partitions, and rendering walls ; this coat is laid the same as ordinary lime plaster ; it is
allowed to stand until the next day. No. i, for setting walls and ceilings, is laid on as thin
as possible with a hand-float, then laid down with a laying trowel, using a little adamant, and
trowelling to a firm face ; no more water than is absolutely necessary must be used for the final
trowelling. Xo. 3 is called "chromolith," and gives a superfine surface. The work is first floated
with Xo. 2 adamant, and after standing one day it is finished with chromolith. When it has been
well trowelled, allow it to stand until three parts dry, then rub with a dry soft cloth until a polished
surface has been produced. Adamant has been extensively used for the internal finish of many
public and private buildings throughout England. Its ready application and quick drj-ing
properties are found useful for most plastic purposes.

Birmingham Waterproof Cement. — For this new plastic, manufactured in powder and a
liquid b\' the Adamant Company, a special claim is made which may be inferred from its name.
It is claimed to be waterproof, and is not injured by excessive heats or cold. It can be finished in
various tints, trowelled to a polished face or stippled. It is also said to be non-porous, and can be
scoured and washed without injury, and is therefore well adapted for infectious hospitals, &c. The
methods of using the waterproof cement are as follows: —

Floating Coat. — A special material for this work, which can be used on brick, stone, wood,
iron, or lath, is prepared by the Adamant Company.

Finishing Coat (Birmingham Cement). — If a fine surface is required, the proportion of
materials to cover i yard superficial is about 12 lbs. of powder to about 5 lbs. of liquid, worked
up to a suitable paste, then applied in the usual way with a float, allowing it to slightly set ; then it
can be trowelled up to a fine face, or stippled as required. Before applying the above, the floating
coat should be allowed to get perfectly dry, and free from dust.

Stippled Work. — This will require about 15 lbs. of powder to about 6 lbs. of liquid to the
superficial }-ard. Materials of any kind or water are not to be mixed with the powder and liquid,
which must be used neat ; and unless this injunction is strictly observed, the results will be totally
unsatisfactory.

Bassett's Plaster Companv. — In 1889, H. A. Rassett, a Birmingham plasterer, obtained
a patent for improvements in a cementitious plaster for plastering walls and ceilings. The
composition consists of dry glue, linseed oil, carbonate of soda, plaster, sawdust, white china clay,
sand, and borax. This material is mixed with plaster and sand (found by the plasterer), and
applied to walls or lath in the ordinar\- way. The patentees claim that it is as cheap as ordinary
mortar, gauged with plaster, and that it is fireproof, a non-conductor of sound, becomes verj- hard
in a few hours, and can be painted upon twelve hours after completion. Xo special experience
is required in using this material — any plasterer can use it with ease. The quantities and methods
of gauging are as follows : —

Floating Coat. — 1^7 pails sand. \\ pails plaster, and i pail composition. This is gauged in
a box with water, and then laid on walls or lath not less than ;; inch thick.

Setting Coat. — This is best mixed in a reserve box, dry, and passed through a fine sieve.

78 Plastering— Plain and Decorative.

I J pails plaster and i pail composition. Gauge in a pail half filled with water, and stir up witii
a flat piece of wood until fit for use.

CORNlCE.s. — For the backing or roughing out, gauge the same as floating coat. A cornice
finishing is supplied read}- for use, onlj- requiring to be gauged same as setting coat. Sawn
or machine-riven laths \\ by \ inch onl)- are to be used, and these not more than \ inch apart.

Blackboard.s. — Bassett's Plaster Company manufacture a specialty in blackboards, whicli
they claim will not wear smooth. For blackboards, a floating coat is first brought up in Portland
cement, and then finished with black finish. The finishing is laid in two coats with a hand-float,
and then laid down with a laj'ing trowel while soft, and trowelled off as it goes in. One bag of
blackboard finish will cover about 20 yards superficial.

ASBESTIC Pl.\ster. — This is the latest form of plaster which has been introduced into Great
Britain. It is made from asbestos obtained from the Danville mines, Quebec, Canada. Asbestos,
technically named " chrysolite," is a mineralogical vegetable, both fibrous and crystalline, and elastic
yet brittle. Apparently combustible as tow, the fiercest heat cannot consume it, and no combina-
tion of acids affects the strength of its fibre. It is used for a varietj- of purposes, especially in con-
nection with building works, its latest development being plaster. Asbestic plaster has been
subjected to many severe fire tests b)- experts in America, Canada, and German)-, and it has given
unprecedented results as to its fireproof qualities. Since its introduction into this country it has
been successfully u.sed in many important public and private buildings. It has been extensively
used in Canada and America by architects of the highest standing. Being composed exclusively
of asbestos it is absolutely fireproof It is odourless, and vermin proof, and contains no organic
matter, therefore its sanitary advantages are \ery considerable. Owing to its elastic, adhesive, and
tough nature there is no fear of its cracking or crumbling. Asbestic, besides being a perfect non-
conductor of heat, is also a non-conductor of sound. For iron and steel columns, &c., asbestic
is invaluable ; exhaustive tests have proved that it is not only a protection against fire but it
entirely preserves metals from corrosion. No special knowledge is required in using asbestic, as it
is laid and finished in a similar way to lime plaster. It is easy to mix, and simple to manipulate.
For brick walls two coats are used, and for lath work three coats for best work.

Directions for using as given by the owners are as follows : — For rough coat, slake about 3
cwt. of lime, and while liquid run through a sieve into a box large enough to hold i ton of
asbestic, mix thoroughl)-, adding requisite amount of water. It is recommended, whenever
'possible, that after the lime and asbestic are thoroughlj- mixed, the plaster be allowed to stand at
least twenty-four hours before being used. For finishing coat, mix two parts of lime to one of
"asbestic finish." Asbestic plaster is packed in bags of 100 lbs. each.

Stone Cement. — Stone cement is now being largely used in Paris for renovating stone
buildings, and is believed to be similar to the cement made by M. Duval. Plasterers are often
called upon to repair stone work with some local cement, and a description of this material is given,
as likely to pro\-e useful. The powder which forms the basis of the cement is composed of 2 parts
of oxide of zinc, 2 of ground hard limestone, and i of pulverised grit. The desired tint is obtained
by mixing with ochre or other requisite colour. The liquid with which the cement is gauged
consists of a saturated solution of 6 parts of zinc in commercial muriatic acid, to which is added
I part of sal-ammoniac ; this solution is diluted with two-thirds of its volume of water. The
cement must not be gauged until required, and not more than can be conveniently used. No plain
water must be used for gauging ; only the solution as described. It is gauged in the proportion of
I lb. of cement to 5 pints of solution. This cement sets very quickly, and attains great hardness.

Selenitic. 79

Paris Cement.—" Ciment de Paris " is the invention of M. Valiin, the Director of the
Gypserie de la Gare, a French cement manufactory. It i.s claimed by the inventor to be at least
equal in quality to English cement, and it is said to possess the durability and the cold appearance
of marble, and that a wall floated and .set with it becomes impermeable to moisture. It can also
be polished and brought to fine face. In the usual method of manufacturing cements it is generally
found very difficult to obtain a thorough burning of every piece of stone. In order to obviate the
unequal burning, the stone is first ground to a fine powder, which is in turn automatically placed on
sieves which shift it into pans heated by gas. A .series of inclined plates, having a gyratory motion,
agitate the powder in each of the pans, thus exposing every particle to the influence of the heat.

SELENITIC.^Selenitic derives its name from .selenite, the chemical term for gypsum. Patent
selenitic was invented by General Scott in 1870. Selenitic sets quickly, and forms a good ground-
work for Keen or other white cements. It is usually made by gauging about 5 per cent, of plaster
(at the time of using) with any lime having hydraulic properties, Lias being con.sidered the best.
Lime may also be selenitised by mi.xing with it sulphuric acid, or by adding a small proportion of
any sulphate. The effect of the sulphate in the lime is to arrest the slaking action, to quicken its
setting, to give the lime a considerable increase of strength, and to enable a large proportion of
sand to be used. Selenitic is prepared for plastering either by means of a mortar mill or a tub. If
in a mortar-mill, pour into the pan 2 full-sized pails of water, then gradually add i bushel of
selenitic, and grind to the consistency of lime putty in a .soft state ; then throw into the pan about
5 bushels of clean sharp sand, hard burnt clay ballast, or broken brick, which must be thoroughly
incorporated. If necessary, water can be added to this in grinding, which is preferable to havin"-
an excess of water to the prepared lime before adding the sand. The water and selenitic must be
mi.\ed together first, and where the improved style of self-discharging mortar is used, it is
recommended to mix the selenitic and water in a tub (as explained hereafter), adding the paste
to the sand or other aggregate proportionately as required. If prepared in a tub, pour in 6 pails
(18 gallons) of water, and gradually add 3 bushels of selenitic, keeping it well stirred until
thoroughly mixed with the water to the proper consistency. Form a ring with half a yard of clean
sharp sand, into which pour the mi.xture from the tub. The whole gauge is then turned over three or
four times, well mixing with a larry, adding water as required. The tub should be able to contain
about 40 gallons, or an oblong box or trough with a sluice ma)- be used. Selenitic should be
kept in a dry place until used. Plastering with selenitic on brick work or stone may be floated in a
similar manner to Portland cement, and requires no hair. P'or plastering with selenitic on lath work,
pour in 6 full-sized pails (iS gallons) of water and 3 bushels of selenitic, adding only from 9 to
12 of clean sharp sand, and 3 hods of well-haired lime putty. When the mill is used, the
haired putty should not be put in the pan until the mixing of the selenitic and sand is nearly
completed, and should only be ground until the haired putty is mi.xed, because long grinding
destroys the hair. The gauge will be found to answer well for all classes of lath work, if the sand
is very sharp. Nine bushels of sand (in the proportion of 3 of sand to I of selenitic) will be
found to answer well for first coating the lath, and 12 bushels of sand (in the proportion of 4
of sand to i of selenitic) may then be used for the floating after the first coat is set. For
common setting, the ordinar\- method of finishing with putt\- lime and washed sand may be
adopted. When a selenitic face is required, the prepared selenitic may be first passed through a
fine sieve, so as to avoid the possibilitj- of blistering, and used in the following proportions : —
4 pails of water, 2 bushels of selenitic, 2 hods of lime putty, and 3 bushels of fine washed
sand. This is use,! in the same wav as trowelled stucco, being well hand floated and trowelled,

8o Plastering — Plain and Decorative.

which will produce a very hard surface. The latter method of working selenitic is preferred bj- the
workmen, because the putt\- lime makes it work "fatter" tlian the method of adding,' the plaster
only, which works very "short" and hea\y. Selenitic should not be used in conjunction with
gauged stuff for cornices, angles, or screeds.

Selknitic Ci..\v Finish. — The use of ground selenitic claj" is said to improve mortar, and
render it more hydraulic. The proportions are as follows : — i bushel prepared selenitic, 3 bushels
prepared selenitic clay, 2 bushels washed sand, i hod of chalk lime putty, and 13 gallons of
water. The mi.xture is well gauged and laid, floated true, and hand floated twice. It is then
•trowelled until a good fair face is obtained. For outside work, a larger proportion of sand may
be used, say from 5 to 6 bushels of sand to the same proportions of the other materials. Selenitic
has been used as a plastering material for many large works, including the Manchester Town Hall,
Drummond's Bank, and the Law Courts, London.

HVDK.\ULIC CEMliXTS. — Hydraulic cements and plasters arc those which have the properties
of setting and hardening under water. Thej- generall}- consist of silica and caustic lime. Cla\-
and magnesia impart greater consistencj- and strength to the compounds. The history of
Smeaton's search after a mortar capable of resisting the inroads of the sea, which he undertook
]jreparatory to building the Eddj-stone Lighthouse, is of much interest, and his discover)' is
really the genesis of an important industry — important in itself as regards the many thousands
employed in the actual manufacture and use of Portland cement, but more important still in
regard to its influence on the trade and commerce of the world, and the possibilities which it
has aflbrded for their development. Although Smeaton did not invent any particular cement,
he was the first to discover that the hydraulic properties of lime depended upon the combination
of the lime with cla)-. To this circumstance the di.scovery of cement is due, and the marvellous
advance we have made in all matters relating to h)-draulic engineering has been rendered possible.

General I'asley, who studied and experimented on this subject, saj-s of Smeaton : " Of all
the authors who have investigated the properties of calcareous mortars and cements from time
immemorial to the present day, our countryman, Smeaton, appears to me to have the greatest
merit ; for although he found out no new cement himself, he was the first who discovered, in or
soon after the j-ear 1756, that the real cause of the water-setting properties of limes and cements
consisted in a combination of clay with the carbonate of lime, in con.sequence of having ascertained
by a very simple sort of chemical analj-sis that there was a proportion of the former ingredient in
all the natural limestones which, on being calcined, developed that highly important quality without
which walls exposed to water go to pieces, and those e.xposed to air and weather only are of com-
paratively inferior strength. B}- this memorable discovery Smeaton overset the jarejudices of o\er
two thousand \ears, adopted bj" all previous writers, from Vitruvius in ancient Rome, to Belidor in
France, and Semple in this country, who agreed in maintaining that the superiority of lime consisted
in the hardness and whiteness of the stone, the former of which may or may not be accompanied by
water-setting or powerfully cementing properties, and the latter of which is absolutely incompatible
with them.

" The new principle laid down b>- Smeaton, the truth of which has recentlj- been admitted b\'
the most enlightened chemists and engineers of Europe, was the basis of the attempts made b>-
Dr John at Berlin, and by \'icat in France, to form an artificial water lime or hydraulic lime in
1818, and of mine (General Pasley's) to form an artificial cement at Chatham in 1826, to which I
was led b>- the perusal of Smeaton's observations, without knowing anything of the previous labours
of those gentlemen on the Continent or of Mr Frost, the acknowledged imitator of Vicat in this

Hydraulic Plaster and Sirapite. 8i

coLintr}-. Every author on lime or cements that I have met with followed the authority of
Vitruvius until after the middle of the last century, when Smeaton came into the field and pointed
out the inaccuracy of his doctrines in the same manner as Bacon had set aside the implicit belief in
the floctrines of Aristotle in matters of philosophy."

Barrow Hydraulic Plaster.— This material is used for plastering, and will carry the
same quantity of sand as ordinary plaster. It does not require so much preparation, and the
running of lime is entirely avoided. Consequently there is a .saving in labour. It sets quickly
and attains great hardness, is non-ab.sorbent and does not blow. It is strongly hydraulic, is
gauged in the proportion of i of hydraulic plaster to 2 or 3 parts of clean sharp sand, mixed
well together in a dry state, and then adding sufficient water to make it work as ordinary
plaster. The principal seat of manufacture is at Leicester.

Hydraulic Plaster Lime. — Hydraulic plaster lime has a ba.sis of Arden lime, and is
especially prepared for plastering purposes by Mr A. M'Ara, whose effort in this direction is the
first of its kind in Scotland. The material, as prepared for the market, is finely pulverised, and
needs only to be mi.xed with sand and water to be ready for use. It requires no slaking, but will
keep for a year or more in barrels or sacks without deterioration. It has all the smooth and
slow-setting qualities and the sand-carrying capacity of common lime, and when used it does not
" blister." This material may be added to ordinary lime to give coarse stuff or setting stuff
hydraulicity and increased strength. It is practically fire and damp proof

Gr.\NITE Plaster. — Calcined gypsum forms the basis of granite plaster. The raw material
is specially treated, so as to form a hard and quick-drying plaster for interior work. Like
similar cements or plasters, it is designed as a substitute for the ordinary lime and hair plastering.
Granite plaster permits of the work being rendered and floated in one coat, and set the same
day. The work may also be painted or papered in two days from finishing. Granite plaster is
delivered in sacks ready for use. It is gauged in a box with water. Xo more must be gauged
than can be used in one hour. In addition to that already described, the Granite Silicon Plaster
Compan\- now manufacture a plaster for plasterers to mi.x their own sand. This, when distance
and carriage is a large item, enables plasterers to bring the cost down to be almost as cheap as
lime and hair plastering. The material first named is already mixed with sand ready for use for
the trade in London, or within four miles of their factory. Granite plaster is an excellent material
where time is limited, as the floating and setting can be laid on the same day, and it attains great
hardness. Its fireproof properties adds to the general value of this plaster.

Sirapite. — Sirapite plaster is one of the most recent inventions as a substitute for lime and
hair plaster. It is formed from a basis of coarse dark, yet hard gypsum, obtained from the Sub-
Wealden Gypsum Works. It is claimed by the manufacturers to be fireproof, labour saving,
economical, and durable. It is free from glue or other such organic compounds, and is therefore
perfectly hygienic, absorbs very little water, and dries quickly. Its use is very simple, as it is
delivered already prepared, requiring no lime or hair, but only the addition of water for the purpose
of gauging. It is very suitable for plastering walls and ceilings, and is invaluable for any kind of
plastering repairs. Sirapite takes the place of the two ordinary first and floating coats of lime
plaster. It is superior to the ordinary lime plaster in point of speed in drying and hardness. It
is equally durable, and certainly much cheaper than most of the many patent plasters of the
present day which are used for the interior finish of buildings. F"or general internal plastering
the cost is about the same as ordinary lime plastering. The material being delivered in bags, it
can be gauged in the several rooms where it is required, and it is unnecessary to provide putty

I I

82 Plastering — P/aiii and Decorative.

pits and space for making ccarse stuff and setting stuff; hence an immense saving in working
and carrying wet materials. Owing to the great strength and tenacity of this material, only a
thin coat is necessary, thus effecting a saving in the amount of material and labour in using.
Two coats onl)- are needed, the second following the first in twenty-four hours. It is easily gauged
and applied, and requires no special knowledge or practice in using. It can be used for new
work, also for repairing old work with advantage. Although not absolutely necessary, sawn laths
are best adapted for its use, as they form a more uniform surface, therefore require less floating
material, and prove more economical. When dry, it is of a light slate colour, and is extremely
hard, and not liable to crack or blow. A beautiful creamy colour can be obtained if desired.

Sirapite quickly becomes hard, dr)-, and smooth, and admits of being papered or painted
in a very short time. For ceilings and lath work, an equal measure of clean sand may be added
for floating coats. For best work, or where time for drying and painting purposes is limited,
the material should be used neat. In this case the lath nails should be galvanised or painted.
For brick or stone walls an equal measure of clean sand may be added for the floating coat. For
ordinary work, 2 parts of sand to i part of sirapite may be used for the floating coat. This
material is gauged in a banker the same as ordinary cement. Sirapite finish ma)- be gauged in
a i^ail of water, allowed to settle, and the surplus water poured off. It is laid and trowelled off
in the same manner as gauged putty and plaster. For all purposes clean water must be used for
gauging. Owing to the initial "set " beginning nearly as soon as the material is gauged, it should
be used at once. E.vcessive gauging or prolonged trowelling should be avoided, as thej- tend
to retard the setting and the ultimate hardness of the material.

BL(jo.\ifielu's Shale Pl.\.STERS. — Shale plasters were patented in 1891 and 1893 by
Mr Bloomfield. Wall rendering consists of from 2 to 3 parts of raw shale, and i part of
hydraulic lime. Fibrine rendering is a similar compound with the addition of sawdust.
Shale plaster is made in Ireland. It has been used in several public and private buildings in
and around Dublin, and has given general satisfaction. It is claimed that it is as cheap as
ordinary lime plastering, and superior in point of hardness. For the sake of Irish enterprise, the
merits of this material should be universally known and used throughout Ireland. The following
is a brief description of the various kinds and methods of using : —

Wall Rendicking. — This plaster is used on brick or stone walls. It dries hard, and may be
set within forty-eight hours after it is put on. From 25 to 30 lbs. is required for 1 superficial j-ard.
When using this rendering, gauge the plaster with clean water in the same manner as ordinary
lime plaster. Brick walls should be well damped before application, to guard against quick
absorption.

FlliklNE Rendering. — This is used as a rendering coat on ceilings and lath work ; 20 lbs.
will cover i superficial yard.

Sll.-\LE Finish. — This is a grej- finish, and used for ordinary work ; 4?, lbs. will cover i
superficial yard. French grey enamel is a beautiful grey, speciall)- adapted for public buildings ;
5i lbs. will cover i }-ard square. Shale or French grey enamel should be mixed with clean water,
in the same manner as ordinary plaster, and worked to a creamy state, then laid on quicklj', and
trowelled as quickly as possible.

Petrur.a. Pla.ster. — This new patent plaster is used as a substitute for lime plaster. It is
compounded from " schist " as a basis, and possesses the advantages of being sanitary, impervious,
and fireproof; indeed, possessing all the properties that a perfect plaster should have. The
qualities of lime and most hydraulic cements are present in this material. It does not crack or

Petnira Plaster and Black Finish. §3

blister, and the ceiling and walls do not require saturating with water. Two coats are needed,
the second following the first in twenty-four hours. The thickness of the combined coats is about
one-third less than is required for lime plastering, hence an immense saving in labour of carrying
and working. Petrura plaster when dry is of a pleasing pearly grey, but it can be supplied in any
reasonable colour. The colouring matter being a part of the plaster, it forms a permanent surface
colour, and it can be washed without injury to the colour or the plaster work. The cost of Petrura
plaster is about the same as lime plaster, but taking into consideration the thinner coat required,
and that it possesses greater strength and hygienic properties than ordinary lime plastering, it is
undoubtedly the cheaper in the end. It is supplied ready for immediate use by gauging with water.
This is a very con\enient and reliable method, as it offers fewer opportunities for adulteration. By
the use of this material the plastering of a building can be completed in a lesser time than required
b)' the ordinary method as used for lime plaster.

Iron Pla.ster. — The following is an improved process for hardening plaster. It is made by
adding i part of fresh slaked lime, finely sifted, to 6 parts of plaster. The lime is sprinkled while
the plaster is being gauged. This limed plaster is gauged as stiff as practicable, and laid, ruled,
and trowelled off without delay. The rule and trowel must be used as sparingly as possible. The
surface is ironed, by working a laying trowel on its flat, with a quick circular motion, using more
elbow-grease than time, and leaving off as soon as the surface is smooth, dispensing with the many
finishing touches which some men think are necessary for a fine finish. When the work is
thoroughly dry, the surface is well saturated with sulphate of iron. The surface then becomes
nearl)- black, but the plaster has greatly increased in strength, the resistance to breaking being
nearl)- twenty times the strength of ordinary plaster. If the surface is required to resist excessive
friction and wet, it is brushed over twice with hot " litharge oil."

Black Finish. — A finished black surface is often required for walls and floors of tennis and
racquet courts. Portland cement mixed with oxide of black manganese is sometimes used.
Steronite plaster, being of a hard nature and black in colour, is also suitable. A deeper black and
harder surface may be obtained by brushing the surface with copperas. Patent mineral black,
invented by Joseph Bickley, a prominent London plasterer, has been successfully used for this
purpose in many London and provincial courts. The following is an American method used for
blackboards : — Clean the walls, and first-coat them with a coat of strong gauged coarse stuff.
When dry, float them with hydraulic lime or selenitic. When the floating is dr>-, finish with
.setting stuff, coloured black with dropblack, or lampblack dissolved in alcohol. When this is dry,
apply two coats of black solution made as follows : — i lb. of white shellac, \ lb. of powdered pumice-
stone, \ lb. lampblack, dissolved in i gallon of pure alcohol.

In 1884, N. F. Potter, of Providence, America, obtained a patent for "improvements in
compounds ada'pted to be used for making surfaces or blackboards, or for hard finish on
plastering." The following is an extract from the specification : —

" The object of this invention is the production of a compound which, when ' set,' shall be
hard and comparatively indestructible. Such compound may be used for various useful purposes,
such as for the production of surfaces for blackboards, as a finish for plaster, &c. When used for
the production of marking surfaces or blackboards, the compound is made from soapstone or talc,
alum, lime putty, black sand, silica, and mortar black. The soapstone or talc is finely pulverised,
the lime putty is made from burnt lime with water mixed therewith to give it the consistency of
mortar, the alum, black sand, silica, and mortar black are all pulverised or finely powdered and
sifted or screened, and all of said ingredients or substances are mixed together, to be used for the

84 Plastering — Plain and Decorative.

marking surface or blackboard in about the following proportions : — Soapstone or talc, lOO lbs. ;
alum, 7 lbs. ; lime putt)-, lOO lbs. ; black sand, ICX) lbs.; silica, lOO lbs. ; mortar black, 88 lbs. The
above-named substances in substantially the proportions given are mixed together in a suitable
receptacle, sufficient water being added to render the composition or coating sufficiently plastic to
be easily spread on any surface, and when it is thus ready for use one-fifth part of plaster of Paris
is added thereto. The blackboard composition or coating may be applied as follows : — The
common brown mortar is applied to the laths of the wall or other surface in the usual way, and
scoured to an even surface ready to receive the blackboard or marking compound or coating. The
said coating, having been previously prepared in the manner above described, is then spread upon
the surface of the mortar or plaster with a trowel to a thickness of about J inch, and smoothed
so as to leave an even surface, which is then brushed with a dry brush, giving a smooth black
surface especially adapted to be used for marking surfaces or blackboards without requiring any
further attention. The compound for marking surfaces or blackboards above described may be
used for a hard finish or plastering by leaving out of said material or compound the black sand,
silica, and mortar black, with the plaster of Paris. If the compound is to be used for forming a
hard finish or plastering, the soapstone is pulverised with alum in the proportion of/ lbs. of alum
to lOO lbs. of soapstone, i part of slaked lime or putty to 2 parts of powdered soapstone and alum
are mixed together, and a sufficient quantity of water stirred therewith to render the whole of the
proper consistency to be spread upon the plastering with a trowel in the ordinary way. The
material thus formed is spread upon the face of the plastering and rubbed over it with a trowel,
thereby producing a hard finish upon the plastering of very perfect and enduring character. If
it be desired to have a very glossy or polished surface, powdered soapstone may be applied dry, or
mixed with water, after which the plastering is rubbed over with a trowel when the soapstone has
been applied in a dry state, and with a brush when applied mixed with water. There are many
different shades of soapstone, so that the manufacturer of the compound can give the hard finish
different shades as desired by selecting from the different coloured soapstone, or, if preferred,
colouring matter may be mi.xed with the puKerised soapstone, alum, and lime putt}-. By
'soapstone' in this specification reference is made to the soft magnesian mineral tcchnicall)'
called ' talc' "

AMEkIC.\N P.vrENT PLASTERS. — America is prolific in the production of patent plasters or
machine-made mortars. The most prominent jjatent plasters in America and Canada are the
Adamant, King's, Windsor, Paristone, Rock, Paragon, Standard, Diamond, Economic, Dillion's,
Asbestic Plaster, Aluminite Cement Plaster, Acme, Aggatite, and Rojal. The last four all claim
to be nature's ow-n plastering, as they are made from a clay or earth found in the Western States
which requires only calcining to make cement.

Adamant, the first and most prominent, was the result of a patent by Carl Straub for a
compound to increase the strength and hardness of calcined plaster. A company was formed in
Syracuse, which succeeded in making a good wall plaster from this patent. They then sold
territorial rights throughout the United States and England — to make Adamant wall plaster from
their patent and formula — retaining to themsehes the manufacture of the chemical retarder and
hardener upon which the patents were based, and selling them to licensees. Their formula required
the mixture of their chemical with calcined plastering sand and other ingredients, and the selling of
a completed product ready for u.se with addition of water onl}-. The local materials in different
territories — even the sand and very often the water — differed so greatly that the licensees were
obliged to alter and change the formula to such an extent that the\' became so expert that many of

Lathing. 85

them made their own chemical and renamed their product. In this way most of the varieties in the
market to-day have originated — many liave changed their method by making the cement or plaster
complete, excepting the sand, which is added by the plasterer when using the material. This
cheapens the product by lessening the cost of freight and cartage.

In a factory where these cements and plasters are made, the mixture is generally exact and
governed by weights ; each maker has tested and mixed his proportions, and the resulting product
is uniform. When one of these plasters is specified there is a reasonable certainty of strong sound
work, although it may not look as well as the old lime mortar. Owing to the better material, it is
more expensive, and to keep down the cost it has to be put on very thin. This does not injure the
quality of the wall, but the opportunity to straighten the defects of carpenter and bricklayer are
greatly lessened. Most of the plasters in the market are good, and deserve attention. If they are
not used and specified, much greater care than is usually exercised by architects is required if they
wish to get good lime mortar.

L.\THING. — Lathing is used on wood, joists, studding, &c., to form a foundation for plaster
work on ceilings and partitions. Plastered partitions were introduced about the end of the sixteenth
century. Lathwood is a straight-grained wood, the outside of fir-trees being used for splitting into
laths. Red Baltic timber makes the best laths. Lath-splitting seventy years ago may be said to have
been in its infancy compared with what it is now. Lath rendering or splitting was formerly done
entirely by plasterers, and was a profitable source of employment in the winter months. Lath
driving or nailing was also allotted to them, but owing to the subdivision of labour, lath-splitting
and nailing in most large towns has become a branch trade, although it is in some places still done
by plasterers. Laths were formerly all made by hand. A large quantity, however, are now made by
machinery. The latter are known in the trade as "sawn laths." An old method of lathing was
done by sawing broad timber into thin boards about \ inch thick, and in width from 3 inches
upwards. The boards were split in position to give a ke\-. Samples of this class of work are still
to be found when repairing old plaster work. Laths are now made chiefly from Baltic or
American timber. This should be specially selected, cut into lengths, and split by wedges into
bolts, with a dowel axe into fittings, and with a chit split into laths.

Laths are usually purchased by the load, bunch, or bundle. A bundle of ceiling laths is
computed to contain 500 lineal feet, but in many parts of the country they are still reckoned
by the long thousand or 1,200 feet, and hence a bunch will contain 100 4-feet laths, and a
bundle will contain two bunches, and will cover 7 yards superficial. A standard bundle should
contain seven score 3-feet, six score 4-feet, and five score 5-feet laths. These terms and
quantities are somewhat confusing, and vary according to the locality. Machine or sawn laths
are fast superseding hand-made laths. Those split by hand give the best results, as they split
in a line with the grain of the wood, and are therefore generally stronger, and are not so liable
to twist as machine made. Cast-iron nails are used for common work ; wrought nails in high-
class work. Galvanised wrought-iron nails have been introduced to prevent rusting. Laths
should be selected in lengths best suited to the spaces between the joists from centre to centre,
and should be fixed about § inch apart. In common work the ends overlap, but for good
work they should be made to butt against each other. This is known as " butt work." They
should also be made to break joint in bays every 3 or 4 feet in width. This gives a better
key, and prevents the cracking of the ceiling or wall along the line of joists. When ordinarj-
laths are used, the studding and joists should never be over 14 inches apart from centre to
centre. The thickest laths are used for ceilings, lath and a half for partitions, and battened or

8*5 Plastcyiiig — Plain and Decorative.

studded walls for jjood work. Single laths are used for ordinary work, stoothed walls, or i)artiti()iis.
All timbers over 3 inches wide should have tillcts or double laths nailed along the centre, ami the
laths nailed to them. This is done to give a better key to the plaster, and is known as " counter-
lathing." Reeds, wickerwork, slates, and wire have been used as substitutes for wood lathing.
Wire and metal sheets are now greatly in vogue as fireproof and material-saving lathing. These
are described as follows : —

Mktal Lathing. — The employment of wire netting or metal sheets as a substitute for wood
lathing is an economical and effectual method for resisting fire, and forms a durable and firm
foundation for plaster work. Wire netting was invented by Edmund Cartwright, who obtained
a patent in 1797. As described, it is sinipK- a wire netting securely stapled to the furring or
joints. Wire lathing used in certain Government buildings erected in Paris during the reign of
Napoleon I. is still in good preservation. It has also been used in American theatres, notably at
Boston since 1853 on walls behind the scenes subjected to rough usage, yet it retains its hold.
Another use to which it has been [)ut to in America is for the inside of freight cars, to render them
when plastered more suitable to conve\- perishable goods. W^ire lathing was first used in England
in the construction of the I'antechnicon, Belgravc Square, in 1841, by Leconte. There are several
other patents for metal lathing which have been introduced during the last two decades, among
which the following may be enumerated : —

E.VPAXDEI) Mktal Lathing. — E.xpanded metal was introduced in this country about si.x
years ago by the inventor, Mr J. T. Golding, of Chicago, whose process is now worked by the
Expanded Metal Company Limited, London. The principal u.se to which the metal has been applied
is as a metallic lathing for firci^roofing, and it has been largcl}' used for this |)urposc for many of
the most prominent buildings throughout the country, and has met with the general approval of
architects, builders, and plasterers, for ceilings, partitions, cornices, and encasing iron work, &c. The
metal is cut and opened out into a network by an ingenious process, the strands forming the meshes
being almost at a right angle to the plane of the sheet before it is cut, so that the plaster becomes
dovetailed in position and a perfect key is obtained.

By means of a recent invention the process of manufacturing expanded metal has been so
completely revolutionised that the material now produced is not only improved but vastly
cheapened, and is made in such increased varieties of weights and sizes of meshes as to greatly
enlarge the scope of its usefulness. As a building material it has assumed a place of first
importance in the construction of floors, suspended ceilings, and solid partitions, which save from
4 inches to 4i inches on each wall, while the ease with which the metal can be applied for encasing
iron work ensures its use becoming more and more general.

Owing to the small amount of sheet metal used in proportion to the area of the expanded
sheet (about one-third), the expansion or contraction of the metal is not sufficient to cause cracking
of the plaster. The metal can also be used for exterior work with Portland cement, and was
adopted for the model of the Eddystone Lighthouse at the Naval Exhibition in 1891, anrl later on
at other exhibition.s, including the Galatea Tower and Hall of 1,001 columns at 01>mpia, &c.

Stanluv'.s Patent Corrugated Woven-Wike Lathing. — The leading advantages
claimed by the inventor are rapidity and security of fixing and fireproof powers.

"JHILMIL" Patent Metal Lath.— The Jhilmil lath is an ingenious yet simple method of
steel lathing for plastered ceilings and partitions, which combines strength with a perfect key for
the plaster or cement. The Jhilmil lath forms an important feature in fireproof construction. It is
made of steel, in sheets 5 feet by 18 inches, 5 feet by 24 inches, 6 feet by 12 inches, and 6 feet by

Metal Lathing. 87

18 inches, convenient sizes to handle and to avoid cutting to waste., readily and quickly fixed by
wire or clout nails to woodwork, or wired to iron uprights.

Its peculiar shape provides for expansion and contraction. The sheets are easilj- cut by an
ordinary pair of snips, and being flexible, it readily adapts itself to any form, and may be used for
cornice brackets, coves, and circular work. The key perforations being uniform, afford a firm hold
for the plaster or cement, which is evenh' distributed and laid. Just enough goes through to grip
round the loops; the key is so perfect and solid that the plaster cannot be detached. The Jhilmii
lath is easy to plaster, and takes a minimum for first or rough coat ; and owing to the strength and
evenness of the Jhilmii, the first coat for most purposes maj- be brought up direct from the lath in
one operation to form a floating coat, and finished with the second coat.

Joists or studding may be spaced at 12 inch, 15 inch, or even iS inch centres. When
fixing Jhilmii lath, sheets should overlap about A inch sideways, the nails about 3 inches apart.
The Jhilmii lath is also effectively used as a fireproof protection to iron and wood columns, girders
&c., as the peculiar corrugations give sufficient air space, so that when plastered thej- are rendered
impervious to fire. The Jhilmii lath is well adapted for the construction of partitions. A strong
and fire-resisting partition can be formed by simply nailing the sheets to wood studs or battens,
which can be spaced at more than one half distance that generallj- admissible for ordinary wood
lathing.

Jhilmii fixed to light iron supports forms an indestructible solid partition, besides economising
space, a great desirability in many kinds of buildings. For solid fireproof partitions, uprights of
I -inch T or H iron section are secured by shoes at the top and bottom, and the Jhilmii lath wired
on one side, and then the whole can be plastered on both sides to form a solid partition li inch to
2 inches thick. Before plastering the steel lath, it should be steadied temporarily b)- light raking
strutting on one side, and then plastered half-way up on the other side from the bottom. When the
plaster is getting dry, or sufficiently firm, the strutting should be removed and the back of the lower
half plastered ; then the top half can be plastered, and the partition completed.

The Jhilmii lath having the same form on both sides, a strong and uniform key is obtained,
thus making a strong and compact body of steel and plaster, the whole being a perfectly sanitary,
vermin-proof, and fire-resisting partition. The weight of Jhilmii lath, including plaster, is about
S lbs. per foot superficial. It has been extensively used in many public and private buildings.

The patentees state that " a piece of Jhilmii lath, 6 inches wide, plastered and laid on a clear
bearing of 18 inches, carried \l cwt. in the centre without any detriment. The advantages claimed
for the Jhilmii jjatent lath are : — Reduction in cost of fire insurances, fewer supports, and saving of
space in thickness of partitions ; the readiness with which it is fixed saves half the time for labour,
besides nails ; the roughing-out coat is entirely saved, and very little plaster is forced to the
opposite side ; time in drying, as the plaster can be used stiffer, and using less in thickness than
ordinar)- three-coat plaster-work, it will dry in less than half the time required for ordinary wood.
lath, and plaster work ; fireproof protection to temporary buildings, and to sides of lifts and other
shafts ; the mortar will go twice as far on the Jhilmii lath compared with wire lath, and a workman
can fix twice as much of the Jhilmii lath on walls or ceilings compared with wood lath, and can
cover twice the surface he can of wood or wire lath in a given time." The application of Jhilmii lath
for various purposes is illustrated b\- details in the advertisement pages.

The Bostwick P.a.tent Fireproof Metal Lath. — The Bostwick patent metal lath is an
American invention, and has been extensiveh- used in that country. Although recently introduced
into England, it has been already largely used for many public and private buildings throughout

S8 Plastcyins[ — Plain and Decorative

the country, and has given every satisfaction. The Bostwick patent metal lath makes a stronger
and better fire-resisting foundation than wood lath, and one which is less liable to crack from
settling of walls or deflections of ceilings. Owing to the peculiar loops and corrugations, the
plaster is firmly keyed, and cannot possibly be detached or fall off. The jjatentee claims that a
plasterer can jiut on about three times as much of this lath in a day as he can of wood lath, and
that a plasterer can lay more than double the number of square yards on this lath than he can on
the wood lath in a given time. Also, that a given amount of plaster will cover nearly twice as
much surface on this lath as it will on the wood lath, because the surface of the metal lath to
be covered is even and unyielding, and the openings being uniform, are sufficient to guarantee a
stronger key, and will not admit of waste mortar falling off from back of the lath. A finished wall
with this metal lath will cost but little if any more than when wood lath is used, because of the
great saving of material and labour. This metal lath is fireproof, therefore a large .saving is
realised on insurance where it is used. This lath is easily and quickly fixed. For fi.xing to iron
ujjrights specially made clasps are used.

Johnson's Patent Galvanised Wirk Lathixc. — This is formed of wire netting :] inch
or smaller in mesh, laid on strips of varnished hoop-iron, and fi.xed with staples edgeways across
the joists. The netting is then spread on this backing and stapled to the joists.

Patent Metal Lathing Sheets. — These are sunk and dovetailed on both sides, and
having serrated edges form a double key for the plaster.

Helical Metal Lathing.— This is the invention of Mr T. L. Banks. It is made of flat
steel wire or ribbon, twisted and woven into convenient size. The stock size is lo feet 6 inches by
2 feet 6 inches. It is fixed by hooks.

Patent Reed Lathing. — This is a German patent, recently introduced into England, and
consists of webbing formed with reeds or rushes secured by wires. Ceilings are constructed by
nailing first a close and then an open webbing to the joists. Both kinds of webbing are made in rolls
of 20 square yards, in widths of from i to 2 yards. There is nothing novel in the use ot reeds as
lathing, as they were the forerunners of wood laths in England — in fact, reeds were used in jjlaster
work in many countries long before the Christian era.

Sl.\te L.ath.s. — Slate lathing was introduced by Nicholson and Waddington nearly a century
ago. Slate laths were at one time largely used in Manchester. They were made of waste slates
of good quality, but which had been either spoilt in the cutting, or were too narrow for the regular
sizes. They measure from 12 to 18 inches long, and are of various widths.

Plaster and W'ike Laths. — A novel lath has been patented in America by Mr \\ . Garvey.
It consists of a bar of plaster -cast in a mould around a stiffening and strengthening wire. The
edges are tongued and grooved so that the entire series of laths may be locked together. These
laths are made in lengths from 12 inches to 48 inches, and in widths from i^ inches to 2 inches.
The laths are secured in place by wires looped over nails driven into the sides of the joists. The
contiguous ends of the laths are separated about i inch, and the intervening space is filled with
plaster, making a flush joint, and at the same time fastening the laths by enveloping the wire core
which is allowed to project beyond the ends of the lath. After they are fixed, the whole surface
is set with gauged putty and plaster or any desired white cement.

CHAPTER IV.

LIME PLASTERING.

Plastering— Plastic Terms— Three-Coat Work— First Coating— Rendering, Floating, Scouring, and
Keying Coarse Stuff— Setting— Scouring, Trowelling, and Brushing Setting Stuff— Coloured
Setting— Gauged Setting — Finishing Angles — Skirtings — Two-Coat Work — Stucco-- Old,
London, Common, Rough, Bastard, and Trowelled Stuccos— Coloured Stucco— Method of
Working Keen's, Parian, and Martin's Cements— White Cement Efflorescen'ce— Cornice
Brackets — Cornices— Corinthian Entablature and Cornice— Mitring— Mitre Mould— Fixing
Enrichments— Mitring Enrichments— Pugging— Sound Ceilings -Cracked Plaster Work-
Repairing Plaster Work— Gauged Work— Joist Lines on Ceilings.

Plastering. — -Plastering is tlie art of covering with or laying on plastic materials to make rough,
uneven floors, walls, or ceilings straight, hard, and smooth. It also comprises the art of decorating
surfaces w-ith enrichments and mouldings. The word "plaster" (in Old English "plaister") is
Anglo-Saxon, and is derived from the Greek W'Ord ij>.-\a.inpov, the Latin being emphTsinim.
This term is loosely employed to describe any form of mortar or plastic matter that can be sj^read
on or around surfaces.

However humble the component parts of lime plaster, and cheap as it may seem beside
marble and expensive woods, it still remains the most useful and fire-resisting material for
encasing rough walls and ceilings. It has not been the fate of this simple, durable, and inex-
pensive material to escape the assaults which ever)- good thing in this world must encounter
at one time or another. It has been called unclean, but it is not so in itself Like many
another wholesome and useful medium, it can be badl}- made, and indifferently applied. This
is due to the incapacitj' and greed of man, not to any inherent defects in itself In spite of
all that has been said against it, it remains the universal lining for dwellings throughout the
civilised world. Wealth may encase walls and ceilings in decorative woods and marbles, but for
the mass of mankind plaster must continue to be the simplest, most sanitary, least costh-, and
most enduring finish for homes. The health of the vast majority of mankind is therefore largelj-
dependent upon the material used in its mixture, and the principles which shall actuate its
employment. For all kinds of lime plastering it is of the utmost importance that the lime should
be thoroughly slaked and mixed with the proper amount of good and clean sand, hair, and water,
and the whole thoroughl}- incorporated and tempered, and allowed to mature before using.
Success largel)' depends on the care bestowed on the materials and their manipulation.

Plastic Terms. — Before describing the different phases of plastering, it will be well to define
the various local technical plastering terms u.sed. The names given to plasterers' tools, &c., have
hitherto been rather \aguc — in fact, each district has had its own nomenclature. Strange to say,
some districts have only a few general terms, many things being described as " this " or " that."
It may be necessar}-, therefore, to point out a ^cw instances of misapplication of terms.

9° P/asfcriiig — P/aiii and Decorative.

■•Hand tloatiiiLj" and "scouring" arc frequcntlj- confounded, whereas they are altogether
different. The technical term "hand floating" means to pass with a light irregular motion,
while to " scour " is to rub hard, or to pass swiftly over. Bearing in mind that a hand float is
used for other purposes, such as laying, .setting stuff, &c., the term " hand floating " is somewhat
conflicting. The term is also apt to be confounded with " floating," i.e., the second coat of coarse
stuff; also when floating with a floating rule. For these reasons, the term "scour," with its
combinations, will be used in this work.

"Lime, sand, and hair" are sometimes termed "mortar," "lime and hair," also "coarse stuff."
The latter term being the most general, will be used in this work. Where there is not a universally
accepted trade term for certain tools and material, a suitable name will be employed, which it is
hoped readers will accept for want of a better one. Plaster of Paris is abbreviated to "plaster," as it is
generally termed in the trade. The following terms are generall)- accepted by architects and
plasterers. Plastering with an admixture of lime, sand, hair, and water is termed " lime plastering."
This kind of plastering is applied in one, two, or three coats, and the description of the work is
generally distinguished by the number of coats applied. Three-coat work is usually described as
" lath, plaster, float, and set," or " lath, lay, float, and set." Two-coat work as " lath, plaster, and
set," or " lath, la>-, and set " ; and on brick walls as " lay and set." One-coat work as " lath and
plaster," or " lath and lay"; and on brick walls as " render." "Lath and plaster, one coat," is the
term used in the Government specifications. " Laying" or " laid " is simply laying a single coat of
coarse stuff on lath-work, leaving a fairly smooth surface with the laj-ing trowel. This one-coat
work is the cheapest kind of plaster, u.sed chiefly for pugging or deafening partitions, floors,
roofs, &c.

In Ireland, ceiling work is usually described as "lathed, scratched, floated, and coated," while
for walls it is described as " scratched, floated, and coated." There are several other modes of lime
plastering which are somewhat vaguely termed "stuccos," but they are chiefly confined to London
and surrounding districts.

TilREE-COAT Work. — Three-coat work is usually specified by architects for all good buildings,
but sometimes two-coat work is specified for inferior rooms, closets, attics, or cellars in the same
building. Three-coat work makes a straight, smooth, strong, and sanitary surface for walls and
ceilings when properly executed. The following is the process for three-coat work, which consists
of first-coating, floating, and setting.

FlRST-Co.\TING. — "First-coating" is termed in London "pricking up," and in America
"scratch coating." It is e.xecutcd b)- la\-ing and spreading a single coat of coarse stuff upon the
walls and ceilings to form a foundation for the subsequent floating and setting coats. Coarse
stuff for first-coating should be uniformlj' mi.xcd or "knocked up," as commonly called. It
should contain more hair than that used for floating, so as to obtain a strong binding key on the
lath-work, and form a firm foundation for the floating coat. Coarse stuff may be tested by lifting
some from the heap on the point of a trowel ; if it is sufficient!}- haired and properly mixed, the stuff
should cling to the trowel when held up, and the hairs should not be more than ^,.r inch apart.
It should be stiff enough to cling and hold up when laid, yet sufficiently soft and plastic to go
through the interstices between the laths. Unless the .stuff is made to the proper consistency, it
will "drop"; that is, small patches, where the excess water accumulates, or at weak or too wide
spaced laths, will fall soon after being laid.

When first-coating ceilings, the coarse stuff should be laid diagonally across the laths;, a
trowclful partly overlapping the previous one — the one binding the other. By laying the stuff

First-Coating at id Re tide ring. 9'

diagonally, the laths jield less, present a firmer surface, and are not so spring)' as when laid
across or at right angles to them. Laying the stuff diagonally, and overlapping each trowelfui,
helps to retain the stuff in its place, which otherwise is apt to " drop." The stuff should be laid
on with a full-sized laying trowel, using sufficient pressure to force it between the laths, and to go
sufficiently through to form a rivet and lap or clinch on the upper sides of the lathing. The
stuff should be laid fair and as uniform in thickness as possible. The thickness should not
exceed f inch, or be less than § inch. If too thick, it tends to weigh down the lath-work, and is
apt to crack ; if too thin, the subsequent scratching is liable to cut the coat down or nearly to the
laths, thus leaving a series of small detached pats which are unstable, and form a weak founda-
tion for the floating coat, and are a source of cracks, and often the cause of the work falling when
subjected to vibration. A thickness of A inch gives the best results.

Scratching. — Scratching is sometimes termed " scoring," also "keying." It is done with a
wooden or iron scratch, which ma_\- ha\e from one to five points. Scratching is scoring the surface
of the first coat to obtain a key for the following coat. The first-coating should be allowed to
stand for an hour or two to allow the stuff to get firm before proceeding with the scratching. If
scratched while the stuff is soft, it is apt to drop ; and unless a man -is careful and light in his
working, the scratch will go too deep, and weaken the body and the rivets of the first-coating. A
wide scratch should be slight!)' angular at the points ; if square, it should be drawn across the work
in a slanting position, so as to give an undercut key. The whole of the surface should be
uniformly scratched with a moderatel)' sharp pointed scratch. The surface should be cross-
scratched diagonall)- ; square scratching cuts and weakens the rivets, especially when the scratch
is drawn in the same line as the laths. Good work is generally scratched with a single lath.
This, like other scratches, should be drawn in a slanting position, so as to give an undercut score.
Single scratching is the best wa)- for circular surfaces. First score it diagonally across the laths,
and then crosswa)-s diagonall)-, keeping the scoring rather square than lozenge-shaped. When too
pointed, the acute angles are liable to be broken when laying the floating coat. The scores should not
be more than i^ inch from centre to centre, or less than i inch from centre to centre. Close scoring
weakens the body of the first-coating, while wide scoring affords insufficient key. Scratching with a
single lath requires thrice or e\en more time than if done with a four or fi\e pointed scratch, but the
work is stronger, as the bod)- and the rivets of the first coating are not cut too deep or otherwise
weakened. In some instances — such as a thin bod)' of first-coating, alread)- mentioned — the
scoring is so deep that the body of the work is cut into a series of detached parts. B)- using a
single lath or point the scoring is also more uniform, and better undercut, thus obtaining a stronger
surface, and a better key for the floating coat. The additional time required for " single scratching "
should be taken into consideration, and annotated and allowed for when making specifications, and
estimating. All .scratching should be done uniformly, taking care not to miss any parts, especially
round door and window frames, wood grounds, or where there ma)' be jarring or vibration. On
the regular and proper scratching depends the ke)- and stability of the succeeding coats.
Scratching with the point of a trowel should not be permitted. The use of a trowel as a scratch
is detrimental to the strength of the stuff and the ke)-. The sharp edge of the trowel cuts the
hair, and thus weakens the stuff. The smooth and thin plate of the trowel leaves a smooth and
narrow key ; the smooth side of the key presents no attachment for the second coat ; while the
deep part of the ke\' is too narrow to receive its due portion of stuff to fill it up, thus leaving a
space for contained air and a more or less hollow and unsound bod)-.

Rendering. — The first coat on brick, stone, or concrete walls is called rendering. Before

93 Plastering — Plain and Decorative.

laying the coarse .stuff, the superfluous mortar in the joints of brick or stone walls should be cleared
off, as the mortar used b)- bricklayers and stonebuilders often contains live or imperfectly slaked
lime, which in many instances is the cause of the plaster work blowing or scaling off. The walls,
whether of brick, stone, or concrete, should be well swept with a hard coarse broom, and thoroughly
wetted to correct the suction, which otherwise would absorb the requisite moisture from the coarse
stuff, causing it to become inert and dry, consequently weak and non-adhesive. In some cases the
joints of brick-work should be raked out, and the face of stone walls roughened by picking. The
coarse stuff for rendering walls does not require so much hair, or to be used so stiff, as for coating
lathwork. First-coating or rendering is generally looked upon as a simple process, but it should
be carefully laid and scratched, as it is the foundation for the other work.

Fi.o.vTlNC. — Floating or second-coating — termed in Scotland "straightening," and in America
"browning" — is the laying of the second coat of coarse stuff on the first coat when dry, to form a
straight surface for the finishing coat. If the first coat has been .standing for some time, it should
be well swept to clear off any dust that may have accumulated during the interval between the
application of the coats. Where the coarse stuff is of a porous nature, a damp brush should be
passed lightly over the first coat as the work proceeds, to prevent the moisture being sucked out of
the second layer, which, if too dry, would tend to crack and fall away. The coarse stuff for floating
should be used in a softer state than for first-coating, because when too stiff the extra pressure
required for laying is apt to crack the first coat on lath work. It also goes more freely and firmly
into the recesses of the .scratching. [It may be here mentioned that a mortar called " Dogga" is
extensively used in South Africa for plaster and building work. "Dogga" is the ground dug up and
tempered with sand, about 2 to i for rendering and floating. Heavy ground requires more sand.
Lime is very expensive in this country, and is only used for the best class of work.] Floating for
lime plastering consi.sts of four parts: — (i) Plumbing and levelling "screeds" to act as bearings
for the floating rule and running mould ; (2) Flanking or filling in the spaces between the screeds ;
(3) Scouring ; (4) Keying the surface. These parts are performed as follows : —

Screeds. — In good work the wall screeds are plumbed and the ceiling screeds levelled. Wall
screeds are plumbed by forming " dots " at the top and bottom of the internal and external wall
angles. If there are wood grounds to receive wood skirtings, they are used instead of bottom dots.
The dots are made by driving two nails through the first coat into the studs or joints of the wall,
allowing them to project about \ inch beyond the face of the first coat. The position of the top
nail should be immediately beneath the cornice bracket. If there is no bracket, the depth of the
cornice should be allowed for. The bottom nail is placed in a line with the upper member of the
skirting moulding. The nails should be placed perpendicular with each other, otherwise the plumb-
bob-line will not work in unison with the gauges. The dots are plumbed by means of a plumb-
rule. If the walls are too high for an ordinary sized plumb-rule to be used, a chalk-line with a
plumb-bob attached, and two wooden gauges, will be required. Illustration No. 13 shows the
nails, gauges, and plumb-bob-line in position. 15, B are the nails in the wall, one just below the
cornice bracket, and the other a little above the floor line ; A, A are the gauges with the line hanging
fair with their shoulders, being the correct position when the nails are plumb. The gauges are
generally cut out of a strong lath. They must be made exactly to the same length. The
plasterer at the top holds the end of one gauge on the top naii, with the chalk-line resting on the
shoulder of the gauge, while the plasterer at the bottom holds the other gauge on the bottom nail
with one hand, and guides the plumb-bob with the other. The nails are now driven in as required
until they are plumb. Care must be taken to allow for a fair thickness for the floating coat. This

Floating, Screediug, ami Flanking.

sNVsNv-.

should not be more than ^ inch, or less than % inch. When working from a wood ground, the top

dots should be kept a little inside the plumb-line, to allow for the traversing of the cornice screed,

because this screed and the gathering at the bottom of the cornice arc apt to throw the wall out of

plumb, unless cut off or allowed for. The dots are completed by laying narrow strips of gauged

coarse stuff close up to and in a vertical line with the top and bottom nails ; the floating rule is

then applied, and the stuff worked down until flush with the nails. The dots

should not be wider than the width of the floating rule, as the rule when bearing

on the nails can onh^ be worked with an up-and-down motion, taking in only

its own width. The length of the dots may vary from 5 to 7 inches, according

to the bearings required for the cornice and skirting running moulds. Narrow

st^reeds are easier, quicker, and truer made than wide screeds ; the latter are apt

to have a more or less wavy surface. This applies more especially to "laid

screeds," that is, screeds that are simplj- laid and ruled off without dots or other

bearings.

Lath dots are sometimes used instead of nail dots, they are generally
used on ceilings and lathed partitions ; they are not so liable to crack the first
coat as nails. They are formed b}- laying a strip of coarse stuff and placing
thereon a straight lath about 6 inches long, and then applying a plumb-rule or
a plumb-bob-line as described for the nail dots. The lath gives strength and
resistance while working the floating rule. After the screeds are finished, the
laths are taken out and the spaces made good. Having finished all the top
and bottom dots, the top and bottom longitudinal spaces in a line with the dots,
or, in other words, the screeds, are laid with coarse stuff The long floating
rule is then applied, bearing on the dots and working up and down in a slanting
position, a plasterer working the rule at each end, and working together, so as
to keep the rule square on edge and uniformly level. Any surplus stuff is
taken off the rule and applied to make up any hollow parts in the screed, or
returned to the gauge board, as the case ma\- be. If the screeds are extra long,
another man (sometimes more) is required to work at the centre of the rule,
also clean the surplus stuff off, and make up any deficiencies in the screed.
After the screeds are finished, the nails must be extracted to avoid rust dis-
colouring the finishing coat. Large surfaces on walls or ceilings should be
divided into ba\-s by narrow screeds placed from 6 to 9 feet apart. This affords
more freedom and regularity for laying and ruling off. Gauged coarse stuff is
sometimes used for the main screed, i.e., the wall and ceiling screeds on which
the cornice is run. In this case the screeds are finished smooth, or so that
they only require a very thin or filling-up coat of gauged putty for the cornice
screeds. The splayed edges of screeds, especially gauged screeds, should be cut
square. A splayed edge being generally smooth, affords little or no key, and also being unequal
in thickness, makes a bad joint for the floating coat. If there are any breaks in the room, the
screeds must be set off square from the side walls, and the projections at each angle of the
breast made equal. The sides are best squared with a large wooden square, and the projections
regulated with a gauge.

Fl.wking.— Flanking or filling in consists of laying the intervening spaces between the
screeds with coarse stuff, and then ruling the surface straight and flush with the screeds, with a

No. 13. — Wall

I'LIMBI.SG.

94 Plnstcriiig — Plain and Decorative.

floating rule. Two squads of men, two or three in each squad, arc required for this purpose — one
squad on the floor, and the other on the scaffold. If the hci<^ht of the room necessitates more than
one scaffold, an additional squad is required for each intervening scaffold. In the latter case, the
distance between the top and bottom screeds would be too great to allow a floating rule to be
conveniently worked. To overcome this difficulty, intermediate screeds must be made at
convenient distances. This is done by stretching a chalk-line from the top to the bottom screed,
and then forming dots flush with the line, and laying the screeds as prcviousl)- described. The
coarse stuff for flanking should be laid upwards, and in an angular line. This [jlan is not so apt to
spring the laths or crack the key at the deepest, which is the thinnest part of the first coat, as if laid
across the laths. After a bay is laid, the surface is straightened jvith a floating rule. A plasterer
at the top and one at the bottom works the rule together uniformly up and down with a cutting
motion, and keeping it in a slightly angular position, so that any surplus stuff may not fall on the
man below. A rule should not be worked on either of its face edges, as by so doing the face
becomes round and uneven, and conducive of unequal screeds. The filling in and ruling off is
continued until all the walls are completed. When elaborate ceilings have to be done, in\olving
the expenditure of much time, the top longitudinal screeds are onlj- formed, and the floating of the
walls left until three or four days before the setting can be begun, as the setting coat made from
some limes adheres better when the floating coat is partly green, or at least not bone dry. As
previousl}- mentioned, the whole process of preparing lime plaster and la\ing it on the walls in thin
coats, with a considerable space of time between the coatings, is conducive to the ultimate hardness
of the whole, the lime being first slaked and then scoured, all this time being exposed to the car-
bonic acid of the atmosphere. Again, each coat is long exposed to the same influence before being
covered with the next, thus enabling each coat to harden by a natural process before the following
coat is laid. All things being equal, it is advisable to allow each coat to stand as long as possible
before proceeding with the next. Where the wall surface is irregular, causing extra thick parts in
the floating coat, the hollow parts should be rendered or "dubbed out," and the surface scratched
before laying the floating coat. The dots for the ceiling screeds arc formed close to the cornice
bracket. If there are no brackets, the projection of the cornice must be allowed for. Lath dots are
best for ceiling screeds. They are formed at all the angles, and made level all round the ceiling.
This is done with the aid of a " parallel ceiling rule." When all the dots are made, the screeds
are finished, and the surface flanked in as already described.

For common work, the wall screeds are seldom plumbed ; but if there are breaks in the room,
the external angles, which arc more noticeable, should always be plumbed. For this class of work
two men generally work together. Working from the floor upwards, one man lays a coat of coarse
stuff about 7 inches wide, and as high as he can conveniently reach up on both sides of the internal
angles; his colleague follows on with a floating rule and rules them straight. Before finishing the
screed, the rule is applied on the portion done, and gradually moved up until one end reaches the
cornice line, to .see if there is a sufficient thickness for the upper part of the screed. The space
between the first-coating and the face of the rule shows the thickness available for the floating coat.
The desired thickness is obtained by laj-ing more stuff on the screed, or working it down, as the
case may be. As the floating rule cannot be worked close up to the angle, a seam of coarse stufif
is formed in the angle.

To allow for shrinkage, and to obtain a firm and .square angle, the scams are left until all the
floating is done, after which they are cut off square and flush with the floating. This is done with
a laying trowel, working it on its flat on the firm floating. Any defects in the angles are made

Floating and Scouring Coarse Stuff. 95

good when scouring the floating. After the vertical angle screeds are firm, horizontal screeds are
laid at the highest convenient line, and ruled with a floating rule bearing on the vertical screeds.
The intervening spaces are then flanked in by laying with coarse stuff until flush with the screeds.
The surface is sometimes ruled fair with a floating rule, but more often straightened with a darby.
After the scaffold is erected, the top portions of the vertical .screeds are laid and ruled with a
floating rule, working it so as to bear on the lower part of the .screed previously made, which gives
a bearing and guide for the rule. After allowing for the depth of the cornice (if not bracketed), the
top horizontal screed is then laid and ruled with a floating rule bearing on the vertical screeds.
The intervening spaces are then filled in with coarse stuff, and ruled in or darbied as previously
described. The ceiling screeds are made close to the cornice bracket, or (if not bracketed) in a line
with the outer member of the intended cornice. A screed is first made at each of the long sides of
the ceiling, and when firm the end screeds are laid and ruled, using the long screeds as bearings for
the floating rule. If the scaffold is in position before the floating is commenced, the vertical screeds
should be formed in one operation. A plasterer on the floor lays the lower part of the screed, while
his partner on the scaffold lays the upper part, after which both work the floating rule together in
their respective positions. Where practicable all screeds should be finished in one operation. In
the event of a screed being too long for an ordinary sized rule to take in the whole length and work
it in one operation, the screed can be made straight by working the rule backwards and forwards
from end to end, and testing the straightness by applj-ing the rule on various parts of the screed.
The straightness is further proved by lightly stretching a chalk-line from one end to the other end
of the screed. After the screeds are firm, the main portion of the ceiling is laid with coarse stuff
flush with the screeds, and then made fair with a darby.

When floating large surfaces with a darby, it should be worked in all directions — longwise,
crosswise, and diagonally — and finishing with a circular motion. For ordinary work a darbj- is an
excellent tool for straightening large surfaces of floating and setting. It also forms a pleasing and
easy surface on circular work. For basement and attic rooms a darby properly manipulated will
form fairly straight screeds as well as the main surfaces. When floating large ceiling or wall
surfaces for plain work, or where it is not necessary that they should be perfectly straight, involving
additional time and material, a hollow surface is preferable to a round surface. .A hollow surface
is not so noticeable, and is less objectionable to the eye than a round surface. It will be understood
that a hollow surface, to be pleasing to the eye if noticed, should flow gradually and regularl\- from
the screeds to the centre of the surface, and not suddenl)- or in wavy parts or patches.

There is an inferior kind of floating practised by piece-workers, in some districts, for cottage
work, and even in some of the modern jerry-built villas. This is e.\ecutcd by floating direct from
the walls in one coat. The surface is sometimes dr\--scoured with a " nail hand float," water and
proper scouring being unknown in this class of so-called plastering. The ceilings are simply laid
with coarse stuff, and the ridges and smooth surface left by the trowel are worked down and
roughened by a few rubs with a hand float. This porous and cracked shell is finished with setting
stuff, gauged with just as much plaster as will hold the materials together for the time being.
The minimum of (or possibly less) trowelling is attempted ; a stock brush being found a more
easy and speed)- tool than a trowel for finishing. The brush is made to perform the trowelling
and brushing off in one operation. This shoddy work is unsafe and unsanitary, and ought not to
be tolerated.

Scouring Co.\rse Stuff.— Scouring floated coarse stuff is of great importance. It not
only consolidates and hardens the surface, but also prevents cracks in its own body and the

96 Plastering — Plain ami Decorative.

subsequent setting coat. For these reasons it should be well and sufficient!)- done. The
straightened coarse stuff should be allowed to stand to permit of shrinkage, evaporation of surface
moisture, and a firm surface, before proceeding with the scouring. Working a hand float on a
soft surface tends to form "water blubs" and hollow parts. When the surface is firm, but not
dry, the work is fit to scour. This is done by the plasterer having a hand float in one hand,
and a stock brush in the other, with wiiich he sprinkles water on the surface, and vigorously
applies the float with a rapid circular motion, using a little soft stuff to fill up any small holes or
inequalities that may have been left after the floating rule. Care must be taken that no part is
mis.sed or less .scoured, and that the whole surface is thoroughly and uniformly scoured. The
floating should be scoured twice, or for best work three times, and allowing the work to stand
from three to five hours, according to the state of the atmosphere, between the first and second
scouring, and one day between the second and third scouring. The final scouring should be
continued until there is little or no moisture left on the surface. To obtain the same strength
and solidity, all other things being equal, coarse stuff composed with a weak lime, or containing
inferior or an excess of sand, or having insufficient hair, or sparsely tempered and used in an
over-soft condition, requires a greater amount of scouring than coarse stuff which is composed
with a strong lime, or containing good sand, and in due proportion, or with an ample quantity
of hair, or well tempered, and used in a moderately stiff, yet plastic condition. Even with e.\tra
scouring, the ultimate strength of inferior coarse stuff is remote and doubtful. This simple matter
is a witness to the fact that inferior or insufficient materials require more labour than good and
sufficient materials, and that the results are somewhat vague and often unsatisfactory.

Kkvinc. — All plastic materials have great adhesive powers, especiall}- to each other. \'et
when laying a thin body of fine material on a coarse material which has a more or less smooth,
dry, and absorptive surface, such as laj-ing setting stuff on floated coarse stuff, the adhesion is
partly nullified. Portland cement, or hydraulic limes which set nearly as soon as laid, require
no scouring, and being left from the floating rule with an open grained or rough surface, a natural
key is obtained for the final coat ; but coarse stuff, which only sets or becomes hard by evaporation
of its moisture, must be scoured to con.solidate the yielding and soft body. Scouring leaves a
close-grained and somewhat smooth surface, offering little or no key to the setting coat. The
floated coat being often dry before the setting coat is applied, the suction varies greatly ; sometimes
it is regular, at other times it occurs in patches. Sometimes the suction is so excessive that the
setting stuff dries up and peels as soon as laid, and in other instances the reverse occurs, there being
no suction at all. In the latter case the setting stuff runs downwards in the form of globules, or
in rixulets. These defects may to a certain extent be corrected by laying the setting stuff while
the floating is still green, or by saturating the surface if the floating is dr)-. Yet to obtain
permanent cohesion in the two coats, it is necessary to key or roughen the surface. This is best
done by brushing the surface as soon as scoured with a stiff whalebone broom, or with a wire
brush. A common plan is to dry scour with a "nail float." i.e., a hand float with the jroint of a
nail projecting about ' inch beyond the sole of the float. When this method is employed, the
float should be worked in a close circular motion, so as to leave a series of close and irregular
indents. The usual and careless way of working the float in a wide circular motion leaves the
indents too wide apart to give a sound and uniform key ; indeed, this method is of little service.
A new tool for keying coarse stuff has been recentlj- introduced in London. This is called a
' devil," and is similar to the nail float, with the exception that there are four nail points projecting
on the sole, one of which is placed about i i inches from each angle. The process of keying the

Setting — Laying and Scouring Setting Stuff. 97

coarse stuff with this is termed " devilling." The work is more speedily and better done with the
" devil " than with the nail float.

After the floating is finished, the next part of interior plaster work is the running of the
cornice, and then finishing the ceiling and walls ; but in order to continue the methods of setting,
the running of the cornice, &c., are described in a subsequent chapter, and the setting and other
parts of wall work are first described, as follows : —

Setting. — Setting is the laying and finishing the final coat on floating. Setting in Scotland
is termed "finishing," and in America "hard finish" or "putty coat." In the best work great skill
and care is required to make the surfaces perfectly true and uniform in colour, smoothness, and
hardness. The material for three-coat work is generally known as "setting stuff." The mode of
making is described in the chapter on " Materials." Setting stuff should not be applied until the
floating is quite firm and nearly dry, to allow for any contraction that may take place in the
floating. If the floating should become quite dry during the time required for cornice and ceiling
work, or where subjected to strong winds or a warm atmosphere, it should be well wetted a day
or two before the setting coat is commenced. This prevents the too rapid absorption of moisture
from the setting coat, and gives a closer union of the floating and setting coats. Before wetting
copiously, a small portion of the floating should be tested with a wet brush to ascertain the degree
of suction. In some floating there is no suction, or at least there is none until the surface has
been damped, and the glaze and sometimes grease has been washed off. Glaze is caused by
slightly hjdraulic lime, also by insufficient scouring. Glaze is more noticeable on first-coating
which has been left smooth by the laying trowel. Grease occurs through friction, also dirt where
the float is left long exposed. These matters of excessive and non-suction, dry, glazed, or greasy
surface, either singly or in combination, also smooth or unkeyed floating, are the cause of cracked
or scaly setting, which one sees more or less in a plaster career. It is therefore absolutely
necessary, to ensure perfect cohesion of the two coats, that the floated surface should be uniformly
keyed, clean, and damp, before the setting coat is laid. Setting consists of laying the .stuff,
scouring, trowelling, and brushing the surface.

Laying Setting Stuff. — The setting stuff is laid in two coats, the second following
immediate!)- upon the first. The la\-ing is best done with a skimming float, which leaves the face of
the first coat rougher to receive the second than if done by a laying trowel, which leaves it smooth.
The second coat should also be laid with a skimming float, which leaves a more open grain for the
purpose of scouring. When laying setting stuff, some men take a trowelful or skimming-floatful off
the hawk, and stoop to spread the stuff from bottom to top with an upward motion, laying the joint
with a return downward motion ; but a smart man can take a trowelful or floatful of stuff and spread
it with a downward motion from top to bottom, and lay the joint with the return motion, thus
saving one stoop in each spread or floatful. This is similar to laying setting stuff on a ceiling. A
man who has a thorough command of the trowel hand alwaj-s lays the stufi" in a long even spread
outward, and lays the joint with the inward return motion. After one side or bay of a wall is laid,
the surface is then scoured, trowelled, and brushed.

Scouring Settinc; Stuff'. — The importance of good and sufficient scouring of setting stuff
with water cannot be too strongly insisted upon. The scouring and the water combined consolidate,
harden, and render the surface of a uniform texture and evenness. The work must be well and
thoroughly scoured, twice with water and an ordinary hand float, and finally with a cross-grained
float. The hand float is worked with a short and rapid circular motion, and sprinkling water
uniformly with a stock brush until the surface is uniform in moisture and texture. After a rest to

98 Plastering — Plain and Decorative.

allow the stuff to shrink, the scouring is repeated, and then it is ready for the final scouring. This
is best done with a cross-grained hand float, which, having sharp square edges, cuts off all ridges
and leaves the setting wit'i a uniform and even surface that cannot be so quickly or as well done with
an ordinary hand float. Water is more sparingly used for the final scouring, using only as much as
will moisten the surface and allow the float to work freely. The scouring is continued until a
dense, even, and close-grained surface is obtained for the trowelling.

Trowelling .-^nd Brushing Setting Stuff. — Trowelling setting stuff is best done by
the u.se of a half-worn trowel (commonly called a "polisher"), the edges of which should be i^erfcctly
straight and parallel. Some men use an old and worn trowel with the point narrower than the heel.
This shape of trowel should never be used for high-class work, since not being parallel, the pressure
when trowelling is not equal, and the heel or widest part is apt to score the surface of the setting.
The trowel and the water should be perfectlj- clean to prevent an>- discoloration. The trowelling
should be done by one man following up the other who is finishing the final scouring. This is
done b)- the plasterer having a polishing trowel in one hand, and a stock brush in the other, with
which he sprinkles water on the surface, and works the trowel in long and vigorous strokes, first
downwards and upwards, and then crosswaj-s or diagonally. This is repeated, using the water more
sparingly, and finishing or "trowelling off" with an up and down motion, and leaving the surface
free from " fat " or " glut." The work is then brushed with a wet stock brush, first up and down,
then crossways, afterwards up and down a second time. The brush is then semi-dried by violent
shaking, or rubbing on a clean board, the work again being brushed as before and finished
perpendicular.

Genkk.M. Ri-:m.\RKS on Sktting. — When the work is required for painting, the setting stuff
is laid on in the form of screeds, and when firm the intervening spaces are laid flush with the
screeds, and the whole surface ruled fair with a floating rule. Should there be any hollow or soft
places (the latter being liable to shrink), they are filled in with more setting stuff and ruled over
again. This is repeated until the whole surface is true and uniform in thickness and firmness.
The whole surface can then be scoured, trowelled, and brushed in one operation. This method has
the advantage of saving joints at the connections between the height a man can laj- and finish the
setting stuff.

Joints, unless carefully done, are an ej-esore, as they are liable to be more or less discoloured
and uneven on the surface. The best method for making good joints in setting stuff, where it is
inconvenient to lay and finish the whole surface in one operation, is to leave the edge of the joint
untrowelled, leaving a scoured margin, so that the adjoining portion can be laid and scoured
without spoiling the trowelling of the first portion. For instance, when setting the walls of a room,
one scaffold high, the top parts are laid down to the level of the scaffold, or as far as convenient, and
the surface scoured and trowelled. The latter must not extend to the end of the scoured part, so as to
leave an untrowelled margin about 4 or 5 inches wide until the scaffold is struck. After the scaffold
is removed, the lower portions of the walls are laid flush with the untrowelled margin, and then the
surface is scoured as before, always going well over the joint. The surface is then finally scoured
with a cross-grained float, taking care to moisten and rescour the untrowelled margin to render the
whole of the scoured surface equal in texture and moisture for trowelling. The surface is then
trowelled and brushed, as already described, taking care to go over the trowelled and brushed joint.
Bj' this method no joints are visible, and an even surface is obtained. Where the suction is slow
or irregular, causing the setting stuff to run or be soft in places, float the surface with a darby until
sufficiently fair and firm to be scoured. A darbj' is very useful for forming a fair surface on setting

Coloured and Gauged Setting. 99

stuff before scouriiiL,^ and trowelling. It forms the next best surface to a ruled surface. A darbied
surface is better and truer than a laid surface.

No more setting stuff should be laid than can be conveniently finished in one operation or day.
Where practical, one side of a wall should be finished in one piece, and sufficient men should be
employed thereon. If the room is not too high, one man or set of men may do the upper part,
while another man or set of men does the lower part The joints are then made while the setting
stuff is green. In high rooms, several sets of men work together on different scaffold.s, each about
6 feet 2 inches apart. All angles should be ruled in with a long floating rule. External angles are
sometimes formed by nailing a running rule or a straight-edge plumb on one side of the wall, to
act as a guide, but external angles are generally finished with a run cement bead or an arris. An
average thickness of i inch of setting coat when finished gives the best result. It should not
exceed fV inch, or be less than ^^ inch in thickness. If too thick, it is liable to crack and flake ; if
too thin, it is liable to peel. Where extra strength, and cohesion between the floating and setting
coats is desirable, the first coat of the setting has a little white hair mixed with it. White hair does
not show through the last coat.

CoMMOX Setting. — Common setting for wall and ceilings is generally used for second-class
work. It is done by laying one coat of setting stuff with a skimming float, and scouring and
trowelling once and brushing twice. Where the floating cracks by contraction, or by using
insufficient hair in the coarse stuff, or by want of scouring, or where the work is green, the cracks
are knocked in with a hammer. The indents are then filled up with gauged setting stuff, and the
whole surface laid with a coat of this material, on which a coat of neat setting stuff is laid, scoured,
trowelled, and brushed in the usual way.

-Slvl.MMlNG. — Skimming is an inferior class of setting, and is only used for the most common
work. It is done by laying a coat of fast-setting stuff with a laying trowel. The stuff is skimmed
over the floating as thin as possible, using only as much stuff as will whiten and smooth the floating
surface It is trowelled once, and brushed as soon as laid.

Coloured Setting. — A beautiful colour and brilliant finish for walls is obtained by mixing
an equal quantity of sifted marble dust with setting stuff, and using this " marble setting stuff" as a
final coat. Ordinary setting stuff is greatly improved by substituting a part of marble, or alabaster,
or gypsum dust, equal in bulk to half the sand generally used. The marble dust should be as
coarse as the sand. Crushed spar is sometimes used in setting stuff to obtain a sparkling surface.
Barytes, scoria, and slag are sometimes used as a substitute for sand, for colouring and hardening
purposes. Brick dust is also used for colouring, and weather and heat resisting purposes. Ground
glass, as used by Indian plasterers, gives a sparkling surface. Setting stuff may also be coloured
with the same materials as described for coloured stucco. Where marble dust or any of the above
materials are used, they should not be added until the setting stuff is required for immediate use.
They should not be used until perfect amalgamation has ensued.

Gauged Setting. — Gauged setting is used where the floating is soft, or where the work is
required for immediate use, and also for finishing gauged floating. This is performed by one man
laying the gauged stuff with a skimming float, while his partner follows up with a darby to la}- the
surface fair. Another batch of setting stuff is then gauged, and one man lays a thin coat with a
trowel, and the other man follows immediately and trowels the work before it is set. The surface
is finished by brushing with a semi-wet brush. Gauged setting should never be scoured unless the
size water is used in the gauge to delay the setting, as it will kill the plaster and render the stuff"
useless. Even if size water is used, the scouring must be slightly and quickly done. If a gauged

loo Plastering — Plain and Decorative.

surface is desirable, a fair and hard surface is obtained b}- simply darbying and trowelling as soon
as laid.

Gauc.ed Putty Set. — Ceilings are sometimes set with gauged putty. This is best done by
first laying a " scratch coat " of gauged putty with a skimming float, and then ])assing a hand float
over the surface (before the stuff is set) to lay down any ridges, and make the surface more even to
receive the second coat. This is laid with a laying trowel, and then trowelled before the stuff is set.
The surface is then finished with a semi-wet brush. Trowelling after the stuff is set, or even has
begun to set, kills the stuff, and causes it to peel. A little washed sand added to the putty makes
a stronger surface, and not so apt to peel.

Putty Set. — In some districts common ceilings are finished with a thin coat of neat lime
putty ; but unless the putty is made from grey limestone, or is of a hydraulic nature, the work is
more or less weak, and in most cases practical!)- useless.

INTERN,\L ANGLE.S. — The setting coat of internal angles on room walls should be ruled fair
and then cleaned out with a feather-edged rule. Before scouring the setting stuff, the angles should
be squared and made straight with an angle float. The angle float is a tool now unfortunately
seldom used, but it is the best tool for making a true angle. In the absence of an angle float, the
angle should be made fair and square with a cross-grained float, and finished with a margin trowel
or the heel of a laying trowel. The common way, used in some districts, of finishing an angle with
a gauging or pointed trowel, should not be encouraged, as it is impossible to make a true angle with
a tool of this shape.

E.xteknal Angles. — The external angles of room walls and windows are generallj- finished
with a bead, but in some instances with a plain arris, splay, or small moulding. The)' are formed
with Parian or other white cement, and usually run after the floating is done. The floating should
be cut square at each side, and down to the brick or lath work. After dusting and wetting the
foundation, a running rule is fixed on one side, and then the bead or arris is run. The run edges
form bearings for the setting coat. A run arris is more speedily done and truer than a ruled and
trowelled arris. In some districts wooden beads are used for external angles. The floating is cut
down at each side of the bead, to allow the quirks to be formed when the setting coat is laid.
When the setting coat is trowelled, the quirks are formed by applying a large-headed nail on the
bead, and drawing it up and down to cut the stuff out. The)' are then finished by working a
laying trowel up and down until smooth and true, and afterwards wet-brushed. The bead quirks
are sometimes cut out by aid of a wooden template, also by laying a straight-edge on the work as
a guide for cutting the stuff out. They are then finished with a trowel and brush, as already
described.

Skirtings. — Skirtings are sometimes formed in wood, but are often formed in cement. Cement
skirtings are far more sanitary than wood skirting, as the former connects the wall and the floor in
one solid fire-resisting and vermin-proof body, whereas wood skirtings, owing to their nature and
construction, afford a ready harbour for vermin, and offer but little or no resistance to damp and
fire — indeed, their hollow formation presents a vent in the case of fire. Parian or other \\hite
cement is generally used where a fine finish is desirable, and Portland cement where the work is
exposed to wet and hard wear. Skirtings are generally run by first roughing out the plinth b)' aid
of a gauge rule bearing on the floating, and then forming a running screed, and fi.xing a running
rule on the plinth. The skirting moulding is then run in the usual wa\^ after which the running
rules are taken off, and the plinth set. The mould plate should be cut to form about i inch of the
top part of the plinth, to form the arris, and a bearing when setting the plinth. The annexed

Stucco.

lOI

No. 14. — Skirting Formation.

illustration (Xo. 14) shows the method of forming the core and plinth, and running the mould-
ing. Fig. I shows the gauge rule (g) in position to form the core Tc). The gauge rule is from
3 feet to 4 feet in length. The plinth is formed by first roughing out with gauged stuff, and then
drawing the gauge rule along the floating to form the core, and
a fair surface for the running screed. Fig. 2 shows a section of
the running mould (m) and the running rule (r) fixed on the
plinth or core (cj.

Two-Coat Work. — This is a cheap method of plastering,
and only used for common work, such as the walls of factories,
warehouses, &c. It is performed by la\-ing one coat of coarse
stuff and then forming the surface fair with a darby, after which
it is scoured once. It is then finished by laying a thin coat of
setting stuff over the surface, and then trowelling once and brushing
twice wet and once semi-wet.

OxE-AND-A-HALF-Co.\T WORK.— This is sometimes termed "coat-and-half work." It is a
species of two-coat work — in fact, it is so termed in some districts. It is done by first laying a coat
of coarse stuff fair, and then scratching the surface with a coarse broom, after which a thin coat of
e.vtra fat coarse stuff is laid, straightened with a darby, and then trowelled and brushed. The
.second coat must be laid while the first is green. This permits the two coats to amalgamate better,
and the surface to be more easily worked and finished.

Stucco. — Stucco is an Italian term usually applied in Italy to a superior species of e.xternal
plastering. According to Vasari, Primaticcio " did the first stucchi ever e.Kecuted in France, and
also the first frescos." In England stucco is a somewhat indefinite term, used loosely for various
plastic mi.xtures in whose composition lime, plaster, or cements enter. Hydraulic lime was
formerly used for external stucco. Roman cement was extensively used for stucco fronts during
the first half of the present century. Selenitic lime has sometimes been used for a similar purpose.
These materials are now entirely superseded by Portland cement. The adoption in England of
stucco externally to give brick houses the appearance of stone is due to Robert Adam. Its plastic
nature enables it to adapt itself to most architectural purposes with very considerable decorative
effects. The more general use of stone and the improvements in terra-cotta have so greatlj-
decreased the use of stucco for fronts, that stucco has become a synonym for a sham, and its real
usefulness for certain works and places has been greatly overlooked. When properly prepared
and manipulated it makes excellent work, and in the near future a large use may be predicted for
its use.

Old Stucco. — ^It has already been shown that stucco was largely emploj-ed b\- the ancients
for plain and decorative purposes. The temple of Apollo at Delos, and even the first Parthenon
under the aegis of Pallas herself, were plastered with stucco. Vitruvius in his seventh book mentions
stucco under the name of opus albarium, sometimes written album opus. Tcctorium opus (from
lector, a plasterer) was a name given by the Romans to a mortar used for plastering. According
to Vitruvius, Palladius, and Pliny, there seems to have been a difference between tcctorium opus
and that called albarium or album opus. Vitruvius says tectorium was composed of three coats of
lime and sand, and three of lime and marble. According to Winckelman, the united thickness of
these coats was not more than i inch. The first coat was of common, but old lime and sand,
and when it was nearly dry a second coat of lime was laid, and on this drying a third coat of fine
lime was laid and made fair. The work was then laid with other two coats of lime and marble.

102 Plastering — Plain ami Decorative.

and finished with a coat of fine marble powder. The marble mortar was frequently beaten to
render it tough and >et plastic, and it was judged fit for use when it would no longer stick to the
trowel. When the lime mortar was dr)-, the marble mortar was laid, each successive coat of marble
mortar being laid before the preceding one was quite dry. The first coat of marble mortar was
composed of coarse ground marble and old lime, the second of fine ground marble and lime, the
finishing coat being neat marble ground to a fine powder, and laid before the second coat was dry,
and worked with a wood float until the surface was consolidated and straight. When dry it was
polished with lime and chalk or with marble until like marble itself Old stucco has been found
so hard and highly polished that it has been used for looking-glasses and tables. In time it
became hard and not liable to crack, and formed an excellent ground for the painting with which
the Greeks and Romans decorated the walls of their houses. According to Vitruvius, this painted
plaster could be detached without fear of injur}-, and detached slabs were carried to Italy and
inserted in the wails of Roman houses. To prevent the cracking of the work done on wood, it was
strengthened by two layers of reeds, one layer crossing the other at right angles. To ensure
dryness, and allow the plaster to attain its proper hardness, the walls were perforated at suitable
places. The tcctoriiim was then decorated with brilliant colours, which were applied on the last
coat while it was fresh ; and to heighten the brilliancy and endurance of the colours the surface
was rubbed over with wax and pure oil. When marble was used with lime in place of sand it was
termed inartmomtitm. The alharinm or album opus was what we term plaster or stucco. The
Greeks named tectorium and albariuin, koniama and kalachrisis.

Slabs of tectorium from the walls of Pompeii and Herculaneum are now in the Museum of
Portici, and specimens are also in the South Kensington Museum. In the Museum of Practical
Geology, London, there are several pieces of old plaster, taken from the ruins of Pompeii, some of
which show that the decorative colours were not applied al fresco, but subsequently to the polishing.
Stucco and plaster are really two very different things. Stucco has for its base carbonate of lime,
generally burnt limestone or chalk, with which putt)- lime and coarse stuff is mixed with sand, &c.,
and used for plastering walls and ceilings. Plaster has for its base sulphate of lime, being made from
gypsum, and is used for cast work and gauging with lime putty, &c. The best kinds of stucco will
resist the action of weather, and can be washed. Plaster, unless specially prepared or indurated,
perishes by exposure, at least in our English climate, and cannot be washed. Stucco is a superior
kind of mortar, and it may be used for plastering or for modelling. The admixture of various
materials with lime and with plaster to form stucco is referred to by many ancient writers. Pliny
mentions fig juice as being mixed with stucco. The Egyptians mixed mud from the Nile with plaster
for some of their work. Elm bark and hot barley water was mi.xcd with the stucco for Justinian's
Church of the Baptist, Constantinople. We find bullocks' blood employed for this purpose as well
in mortar for Rochester Cathedral in the latter part of the ninth century. Bishop Gundulph
(1077-1108) is stated to have mixed blood with lime to make it hard. Hot wax mixed with lime
was used at Rockingham Castle in 1280. White of eggs and strong wort of malt were mixed with
the lime used for Queen Eleanor's Cross at Charing Cross in 1300. Pitch and wax were mixed with
the lime used for Edward II.'s works at Westminster in 1324. Media.>val builders habitually used
beer, eggs, milk, sugar, gluten, &c., for mixing with mortar for cathedrals. Frequent entries found in
the archives prove this. One reads, " For beer to mix with the mortar." Bess of Hardwick's ma.sons
used beer in their mortar, having to melt it in the cold winter of her death. Old plaster is found
to have rye straw mi.xed with it for binding, and was very strong. A brown substance somewhat
like plaster, but full of fibre, was in use in the sixteenth century. The accounts for the repair of the

London Stiiccos. Jos

steeple of Xewark Church in 1571 contain an entry, "6 strike of malt to make mortar to blend with
ye lyme and temper the same, and 350 eggs to mix with it." During the building of the Duke of
Devonshire's house at Chiswick, the exterior of which was plastered with stucco, the surrounding
district was impoverished for eggs and butter- milk to mix with the stucco. Peter le Neve's mention
of rye dough stands not alone, as Sir Christopher Wren's " Parentalia" T 1750) records the use of
"marble meal" as the old and still the modern way of stucco work in Italy. "Marble meal"
simply meant marble dust ground as fine as meal. This dust was used for fine work. Sugar and
the gluten of rice are used in Ceylon and India. The Chinese use a rich unctuous earth in com-
bination with lime. In some parts of France urine was used with plaster in the sixteenth century.
Nearh- all these admixtures are to retard the setting, to allow more time for the manipulation
of the stuccos. Some are to accelerate the setting, and some arc to increase their ultimate
hardness.

Many of the ancient buildings in various parts of the universe, which were built of mud, clay,
or sun-dried bricks, had their surfaces decorated with hand-wrought stucco. During explorations
in Peru, South America, Dr Le Plongeon found some interesting specimens of ancient plaster
work in a number of the ruins of the earl}- Peruvian houses and cities, which date back to remote
antiquity. At Chenni Concha he found the fragments of some ancient ornamental stucco on the
adobe (or clay-built) walls, covered with bas-relief decorative designs, while the material is after
many centuries still in good preservation. The design and the execution are of considerable merit,
and it seems wonderful that a people ordinarily held to be but little better than savages could have
conceived ornamentations so aesthetic, and have executed them with such high technical ability.

Cav. ]\I. Guggenheim, who has had much stucco work done in the Palazzo Papadopoli and
elsewhere, gives the following formula for the stucco diiro which is still used in \''enice : — It is old
stone lime, slaked for three }-ears at least, mixed with Carrara marble dust, ground as fine as flour,
into the consistency of paste. This of course is for the finishing coat, the rough modelling being
executed with a coarser material. Italian stucco is described in Chapter XVI.

London Stlxcos. — There are four kinds of so-called stuccos which are used in London and
the South of England. They are known as common, rough, bastard, and trowelled. The methods
of working these species of plastering are embodied in the description of three-coat work — in fact
the only difference between these stuccos and three-coat work lies in the setting coat, the first-
coating and floating being the same for all. Some of the above terms are now only used by
workmen, and the use of stuccos is to a great extent superseded b)- Portland cement for exterior
work, and Parian and other white cements for interior work. The following is a summary of the
materials and methods used for the various stuccos.

Common Stucco.— Common stucco was jarincipally used for exterior work. It is composed
of 3 parts of coarse sharp sand to i of hj-draulic or grey lime, to which a small portion of hair is
added. It is laid in a similar way to ordinary rendering in one coat, and the surface finished with
a hand float.

Rough Stucco.— This is generally used for plastering churches, corridors, and entrance
halls to imitate stone. The work is floated with ordinary coarse stuff, and then set with stufi"
composed of 3 parts of washed sharp sand and 2 of grey lime putty, not chalk. This is laid with a
trowel, and then ruled in with a straight-edge until the surface is full and fair. After this it is
scoured with an ordinary hand float, and finished with a " felt float," not to raise the grit, but to
keep it down. The felt float is an ordinary hand float with an unplaned sole, on which a felt sole,
about \ inch thick, is fixed with gauged plaster. This tool before using generally requires to be

104 Plastering — Plain and Decorative.

rubbed on a straight stone to obtain a uniform face. Great care must be exercised when laying
and finishing the surface, so that no joints arc shown, or else the>- will never dry out. When
wanted to represent ashlar masonrj-, the surface is set out with lines to the size of the required
stones, and then the lines are indented to form the joints with a jointer or the ring end of a key.
The grain of the stone can be better imitated by patting the surface with the hand float as a finish.
The staining of stucco to represent the colour of stone is done by diluting sulphuric acid (oil of
vitriol) with water, and mixing with it the liquid ochres and other colours to the required tints.
The setting stuff may also be mixed with the ochres before using. A small portion of the coloured
stuff should be dried to ascertain the tints before laying the whole surface.

Bastard Stucco is somewhat better in qualit)- than ordinary setting. The final coat is
composed of 2\ parts of washed sharp sand and 2 parts of chalk lime putty. It is laid in two
coats with a skimming float, scoured up once, and then trowelled off and brushed.

TKOWKLLt;!) Stucco is generally used for work that has to be subsequently painted. The
stuff for the finishing coat is composed of from 2i to 3 parts of washed sharp sand to 2 parts of
chalk lime putty. The sand is not so fine as that used for ordinary setting, being washed through
a sieve having about 12 mesh to the inch. The stuff is laid on, and then traversed with a
floating rule in all directions, up and down, across and diagonally. The surface is then scoured
up without water, and after a rest to admit of shrinkage, the surface is scoured up three times with
water ; the trowel to immediately follow the third scouring up. This trowelling is continued until
the work becomes so hard that no impression can be made on the surface ; it is then brushed
off with a soft damp brush (not wet), first horizontally, then diagonally, and finally perpendicularly,
leaving a brilliant face. When dry, the gloss goes off, and leaves a fine surface for paint.

Coloured Stucco. — The Italians execute lime stuccos in colours, mixing in the lime
\arious oxides — i.e., blacks are obtained by using forge ashes containing particles of iron ; pearl
greys are made by mixing ashes with the marble ; greens are obtained by using green enamel, with
a large proportion of marble ])owdcr, worked up with lime-water; browns by mi.xing ashes with
the lime and marble in proportions varying with the tints desired ; reds by using litharge, or the
red oxide of lead ; blues b)- mixing 2 parts of marble powder and i of lime, and i of oxide or
carbonate of copper. Stucco may al.so be coloured with the same materials as described for
coloured setting, also for sgrafifitto and concrete.

Method of Working Keen'.><, Parian, and Martin's Cements. — When describing the
technique or practical manipulation of Parian and the other white cements which have been
invented in the nineteenth century, it is only natural that one should feel animated by a peculiar
pleasure, because in these cements, British industry, aided by modern science, has, as far as is
known, equalled, if not excelled, anything of the kind produced by the ancients, tested by any
experiment, whether for strength, solidity, or durabilit)-. With these a great saving in time
can be effected, as work can be begun and finished in one operation, without waiting for the
different coats to dry, as in ordinarj- lime plastering. For sanitary purposes they are unequalled.
This, combined with their chemical properties, which enables them to be painted, papered, or
distempered as soon as finished, renders them the most valuable of all plastering materials in this
go-ahead age. They are free-w-orking, sanitary, durable, and practically fireproof They are
the verj- be.st materials for plastering walls, dados, or in similar exposed positions. For skirtings
they are invaluable, as they offer an effectual resistance to fire, vermin, and dust. When properly
manipulated, they can be worked to a porcelain-like surface. They are nearly perfection, and
constitute perfect plasters for most interior work. Their only drawback is that they will not resist

Method of Working Kccifs, Panan, and Martin's Cements. io5

the effects of moisture. It is therefore imperative that damp walls should be floated with Portland
cement, where a white cement finish is desirable. By the aid of the hard and sanitary white
cements plastering has become a tangible reality, instead of a comparative makeshift, what it has
hitherto been. The object aimed at in the invention of white cements for internal use is to produce
a material of which plaster is the base, which shall set sufficiently slow to be easily manipulated,
become dense, hard, non-porous, and may be painted as soon as finished. Before the introduction
of these cements, all making good, as it is technically called {i.e., patching holes in old plaster
work), used to be done with neat plaster, plaster and sand, or lime gauged with plaster. Keen's
was first introduced, then Parian, and lastly Martin's. Parian being most in demand, claims
priority in description. Parian and other white cements are uniformly reliable in quality, but
through the rapacity of some contractors the cements are often adulterated with plaster to lower
the cost, and hasten their setting. This adulteration causes the cement to swell, and in many
instances to peel or fall off. Even if it does adhere, it never attains its due hardness, and thus is
no better than ordinary plaster. Unfortunately adulteration brings discredit on the cement and
the trade. The only remedy is proper super\-ision by a plasterer who possesses a thorough know-
ledge of plastic materials and the methods of using them. If plasterers were awarded certificates
of competency, adulteration would be prevented, and good work ensured. Honest employers
would find this beneficial, for scampers can only thrive where there is a lack of knowledge of the
technique peculiar to plastering, and which only plasterers of experience really possess.

In using Parian cement on lath-work, exceptional care must be observed that all the lath nails
be galvanised, or painted over, or coated with shellac, to prevent rust. For this same reason all
nails used for plumbing and levelling purposes must be extracted after the screeds are .set. For
first-coating and floating ceilings with this material, the proportions for best work are i part of
cement to 2 of clean sharp sand, adding about the same quantity of hair as for lime plaster.
Walls are generally floated with Portland cement in the proportion of i part of cement to 3 of
sand, and finished with neat Parian. This system is adopted as a matter of economy, as Portland
cement is cheaper than Parian ; and where time is no particular object, makes equally as good
work. For walls intended to be painted or polished immediately, it is necessarj' to mix the
materials in the same proportion as for ceilings, with the difference that more sand may be used — sa\-
2 parts of cement to 5 of sand. The reason for this is, that when floated with Portland, and finished
with Parian, an efflorescence invariably appears on the finished surface, and until it has time to
dry out, it is inimical to successful painting or polishing. Gauging is an important point ; it must
be carefully and quickly done to ensure success and obtain the full strength of the cement. For
first-coating or floating ceilings, empty a sackful, or half a sack, according to requirements, in a clean
banker ; then add the sand in the proportions already given, and thoroughly mix the cement and
sand while yet dry ; then form a ring, and pour in the water, taking care not to pour in too much,
as it must be gauged, and used as stiff as practicable. There will be no difficulty in thus using
it, as it will take some hours to set, according to the season of the year (quicker in summer than
in winter). When the water is in, add the hair (which must previously be well beaten and soaked ,
and gauge the whole mass together. Then begin the first-coating, scratch it in the usual manner,
and so on, until the whole ceiling is first-coated. It should stand for twenty hours before starting
to float. Hair is generally omitted for common work, or where the laths are close.

Parian cement ceilings should be dead level, and have a uniform and straight surface ; there-
fore the screeds should be levelled, made narrow, and the sides cut square, and when firm the whole
ceiling should be ruled in with a floating rule, sufficiently long to reach from screed to screed.

'o6 Plastering — P/aiii ami Decorative.

The floating stufi" is gauged moderately stiff, and laid diagonally across the line of laths, so as not
to spring the lath-work, or disturb the key of the first-coating. After the ceiling has been laid, the
floating rule is applied, a man holding each end (and one at the centre if extra long). It is then
drawn gently and steadilj- along, filling up hollow places, until the whole surface is straight and
true. When the surface is firm, it is brushed with a coarse broom to form a key for the finishing
coat. If there is a Parian cement cornice to be run, the usual mode for plaster and putty is
adopted for the running rules. The screeds should be made sufficiently smooth to run on, without
forming an extra thickness or traversing screed. The cornice is roughed out with the same kind
of material as used for the floating, employing a muffled running mould for running the rough
stuff. It may not be practicable to rough out all the cornice at once, as this stuff docs not set
quick, therefore it may be necessary to leave it for a time until the stuff stiffens. No definite
directions can be laid down in this matter, as the suction is greater in some seasons and rooms
than in others. A little extra hair, also extra stiff gauging, is of service to make the stuff cling
together, thus allowing the work to be roughed out sooner. The running moulds must be made
of strong zinc or copper (no iron to be used on any account). Where the work is in cornices,
skirtings, architraves, &c., the mould should be muffled with a zinc or copper plate. If there is
only a small quantity to be run, a plaster muffle may suffice. After the cornice is roughed out, it
is finished with neat Parian, and then the mitres formed in the usual way.

In preparing to finish a large space (ceilings or walls) it is absolutely necessary that no more
should be laid than can be finished the same day, therefore as many men should be put on the job
as will accomplish that object, as no sign of a joint should be shown on the surface. In the case
of large or high walls, the scaffold should be so arranged that the men can work the whole wall
from the cornice down to the skirting in one operation. If a wooden skirting has to be subsequently
fixed, one end of the rule bears on the fixing grounds ; but if a Parian skirting is specified, it is
generally run before the walls are finished, and allowed to get thoroughly hard, so as to bear the
end of the rule used for the finishing coat. The lower end of the rule is cut to fit the upper
member of the skirting. Another wa>' is to nail a board on to the end of the rule, so that it bears
well on the plain plinth and clears the members of the skirting. The cornice screed must be keyed
with a drag before the finishing coat is laid. For large cornices it is often desirable to traverse
the running screeds. In this case they must be cut down to the floating, leaving only the margin
formed by the running mould. This margin forms a bearing for the top end of the rule. In some
instances a special margin or bearing is cut at the outer members of running moulds for cornices
and skirtings, and when run they form a bearing for the floating rules.

When ready for the finishing coat, empty as much as required of neat Parian cement into a
clean banker, and gauge it smooth and stiff"; then soften it down to the desired consistency, always
bearing in mind not to make it too soft, as sloppy stuff" for any purpose is ever to be avoided.
The gauging should be so arranged that when one batch is in use another one is ready, which
prevents delay in laying the whole space, thereby ensuring similarity of texture and results. The
thickness of the finishing coat should not exceed i inch. When there are about a dozen yards laid,
two men must follow on and rule the surface fair from screed to screed on ceilings, and top to
bottom on walls. The greatest possible care must be observed that the whole surface is ruled in
fair and uniform, otherwise the surface will be imperfect.

White cements, owing to the suction of the walls or ceilings, have a tendency to shrink more
or less, according to the stiff'ness of the gauge and the suction, therefore they must be ruled in
twice. When the coat already laid is firm, then some more cement, gauged softer than the first,

Efflorescence in JVhite Cements. 'O/

should be laid thinly all over, and ruled as carefully as before. Having done this, the whole
surface is nearly read>- for scouring. It is allowed to stand for an hour or two, or until quite firm. If
scouring is attempted before, it will work into hollows, and a bad job will be the result. If the finger
cannot make an impression upon it easily, it is sufficientlv firm, and then all hands begin to scour
the work, using very little water, and working the hand float with a circular motion. The hand
float must not be worked long on one spot, but kejit moving over all the surface within reach, and
working back again until the whole surface has an even grain or te.xture. The whole work must
be scoured twice to bring it up to a fine solid surface. When there is about half of the wall
scoured, two or more plasterers can continue the scouring, and the remainder of the men go back
and start the trowelling. This must be done with good long strokes, using very little water, and
taking care not to dent the surface with the trowel. After the men have finished the scouring, the)'
come back and start at the beginning with the second "trowelling off" or final trowelling. This is
done both vertically and horizontally, and when the work begins to harden, the trowel is laid
on the near edge and worked with a cutting motion downwards. This is repeated all over the
work until every particle of glut or "fat" is cleared off the surface. If the work has to be polished,
this cutting action with the trowel must be followed with a 9-inch joint rule and a damp brush, but
the work must be hard before this last can be attempted. Work carried out on the above plan
will reflect credit on the material and the workers. The same methods apply equally to Keen's
and Martin's. Martin's is preferred by some plasterers for running cornices because it sets quicker
than Keen's. For plain surfaces, such as walls and ceilings, it sets too quick, and has to be "killed"
(that is, working the stuff again and again with water until the initial set is stopped or "dead")
before it can be conveniently used. Although it finally sets fairly hard, it never attains the same
degree of hardness as Keen's or Parian.

Several other white cements and plasters have been introduced during the last two decades.
They are enumerated and described in Chapter III.

White Cement Efflorescenxe. — For work that has to be painted, care must be e.xercised
in the selection and manipulation of the materials used for the plaster work, so as to avoid as far as
possible subsequent efflorescence. In the manufacture of Keen's, Parian, and Martin's cements,
Keen's original process is doubtless the best. It requires, however, great care in carrying out, the
chemicals used and temperature employed requiring to be suited to the peculiarities of the gypsum.
The desired result is extreme hardness, combined with non-efflorescence. Keen's cement is practi-
cally non-efflorescent, as if applied on a dry wall containing no soluble salt, in itself there would be
no efflorescent that would spoil paint. Perhaps one should not say that Keen's cement, or at least
all brands of it, are absolutely non-efflorescent, as there is generall\- a powder\- coating comes on
the surface, just enough to whiten a coloured handkerchief, something like the coat of puff powder
used on some female faces. On no account should Keen's cement be used on walls as a preven-
tive of damp, as it is useless for this purpose. If used on a damp wall, or in places exposed to
atmospheric influences, it will effloresce more or less, as its base is gypsum, which always remains
soluble. In damp situations the walls should be rendered or floated in Portland cement before the
finishing coat of Keen's cement is laid. The same remarks apply to Parian and Martin's cements.
The Keen's cement manufactured by Howe of Carlisle is practically non-efflorescent.

Cornice Bk.vckets. — Brackets or cores are used to decrease the amount of materials and
weight, and also to form a foundation and support for cornice or other mouldings. For large
exterior work they are generally formed with stone, and for small work bricks, tiles, or slates are
used, which are built into the walls as the work proceeds, and roughly fashioned to an approxi-

loS P/nstcfiiii: — F/aiii mid Decoy a the.

ination to the profile of the intended cornice or other moulding. For interior work the brackets
are sometimes constructed with metal lathing, also with spikes and tar bands, termed " spike and
rope brackets," but the oldest and most general way for cornice mouldings are " lath brackets."
The " brackets " on which the laths are subsequently nailed are cut out of boards from \ inch to
\\ inches thick, according to the size and form of the cornice. The section of the brackets should
be about i inch less than the profile of the proposed cornice to allow for a thickness of lath and
plaster. The thickness of the plaster should not exceed i inch, or be less than I inch. If too thick
it is a waste of materials, and the undue weight is apt to pull or spring the laths from the brackets,
and if too thin the stuff is apt to crack. The profile of the bracket need not follow closely that of
the cornice, but a general or appro.\imate outline of the most .salient members followed. An)' thin
projecting members may be subsequently strengthened by means of projecting nails and tar
strings similar to a spike and rope bracket ; also by using extra hair and plaster in the roughing-
out stuff Brackets for enriched cornices require special notice. Unless a due allowance is made
for sinkings for the thickness of the cast enrichments and a correct form of bed, there will be
unnecessary trouble in cutting and hacking the lath work and brackets when the running of the
cornice is commenced. There is a marked difference between the section of a running mould for
an enriched cornice and that of a plain cornice, even if the profile of both are the same. To avoid
mistakes of this nature the plasterer should supply the carpenter with a section of the brackets
taken after the bed of the enrichments are set out on the tracing of the proposed cornice.

Scotch brackets is a term applied to a method sometimes used for coring out angles, to save
materials where there are no brackets, and for small mouldings. This is effected by placing the
mould in position and then fitting a piece of lath in a vertical position, and allowing a space of
about \ inch from the face of the lath to the nearest part or most prominent member of the mould.
A mark is then made on the ceiling and wall at the top and bottom of the lath. Similar marks
are made at the other end of the wall and ceiling, and then a line is struck on the marks, from
end to end of the ceiling and wall, by means of a chalk line. The stuff which forms the parts of
the screeds inside the lines is cut away, dusted, wetted, anJ then a narrow strip of gauged coarse
stuff is laid along the lines where the ceiling and wall screeds are cut, and the laths, which have
been previously cut to the length of the first or trial one, are fi.xed vertically into the gauged
stuff, keeping them apart as in ordinary lathing. They are further secured by laying strips of
gauged stuff on the outward surfaces at the top and bottom ends. After the stuff is set, the
cornice is run in the usual way.

Cornices. — Cornices, either plain or enriched, are formed with a running mould cut to the
profile of the intended cornice. The formation of cornices consists of constructing the mould,
making the running screeds, fixing the running rules, running the cornice and mitring the angles,
with the addition of fixing the cast ornament for enriched cornices. Cornices were formerly run
in short lengths and in sections. Two, three, and even four moulds were employed for cornices
that are now done with one. For large cornices, where the mould is difficult or sluggish to run, or
apt to jump, the bearings .should be greased or brushed with soap or dusted with powdered black
lead or French chalk. Running moulds are run in Scotland with the left hand, from left to right,
and the mould plates are also fixed to the left hand side, having the bevelled part of the stock to
the right or running side. In England the plates are fixed on the running or right side, and the
mould is run with the right hand from right to left. The Scotch way of running from left to right
with the left hand allows more freedom, especially in small mouldings, for the right or trowel hand
to assist in feeding the cornice with the stuff that gathers on the mould. It also gives more

Riin/iiiig Cornices. '09

freedom to his partner who is layinij on the stuff, as with the hawk in his left hand and his trowel
in his right he is able to work in a natural position, namely, from left to right, as in laying coarse
or setting stuff on walls, whereas, when the mould is run with the right hand, and from right to
left, the worker has not so much power or freedom in assisting to feed the mould with his left
hand. His partner, who is laying the gauged stuff, is working backhanded, and if using a laying
trowel, can only work from its heel instead of from the point as is usual ; and if using the large
gauging trowel for laying on, every trowelful used must be put on with a backhanded turn. It
may be a matter of opinion as to which method is better, and depends a good deal upon which way
the man has been taught, but the manner of running the mould and laying on of stuff from left to
right, the same as in writing, is the most natural. Running screeds are used as bearings for running
moulds. They are composed of gauged stuff, and made straight with floating rules. Screeds for
cornices are formed with raw or with gauged coarse stuff. They are next traversed, termed in the
North of England "sweatened," and in Scotland "justed." The line of the screen is got by placing the
running mould in its true position at one end of the wall, and making a mark on the floating screeds
at the outside of the nib and the bottom of the slipper. The same operation is repeated at the
other end of the wall, and a continuous line from one mark to the other made on the ceiling wall
by means of a chalk line. A narrow strip of gauged putty and plaster is now laid on the lines by
one man, while his partner follows on with a traversing rule, working the rule with a slanting
motion, and moving backwards and forwards until the screed is just and true. Where the walls
are very long, running screeds are done by two men working a long straight-edge or floating rule.
The screed is afterwards further fined by drawing a cross-grained hand float three or four times
over it in a longitudinal direction. Where the coarse stuff screeds are not gauged, the running
screeds are made in a similar manner, but the putty is mi.xed with an equal proportion of setting
stuff before gauging. The addition of sand gives more resisting power to the wear of the nib and
slipper of the running mould. The running screeds are made on the long sides of the room, and
when set they give a bearing for the end screed in its true position at one end of the wall.

Fi.xing the running rules is the ne.Kt operation. This is done by placing the running mould
in its true position at one end of the wall, taking care that the mould is " square," that is, that the
perpendicular parts of members are plumb with the wall. This ma\- be tested with a plumb-
bob hanging over the side of the mould, and by seeing that the line of the plumb-bob hangs
properly over a marked line which has been previously made by squaring off from a square
member or by extending a parallel line from an upright member of the mould. The method of
plumbing running moulds is illustrated in Chapter VII. When the mould is plumb and square, a
mark is made on the ceiling screed at the outside part of the nib, and another made on the wall
screed at the bottom of the slipper. The same operation is repeated at the other end of the wall, and
the line extended from mark to mark by using a chalk line. The line in this case should be blackened
by means of charcoal or burnt stick, as it shows better than a white line on the light-coloured screeds.
As the chalk line may sway when striking the wall line, this line should not be trusted for fixing
the running rules to. This may be proved by placing the mould every 3 or 4 feet apart in the
length of the wall, taking care to keep the outer edge of the nib at the ceiling line ; then marking
with a gauging trowel at the bottom of the slipper, \ails are now driven into each of these marks
and left projecting as a guide for fi.xing the running rules. The running rules should not be less
than 2i inches wide or more than 3i inches wide and A inch thick, being made out of good red-
wood or pine planed on both sides and edges. The rules are now fixed into the wall screed either
by nailing them to the studs or into the joints of the walls. They are also fixed by wetting one

no Plnstcn'jte — Plain and Decorative

face of the rule and laying dabs of gauged putt}- and plaster about 2 feet 6 inches ajjart. The
rules are now pressed on the wall while the stuff is soft, taking care not to force the guide nails
out of position. The rules are further secured by laying patches of gauged stuff underneath the
rule partly on the wall and rule where the dabs are. When the rules are fi.xed by nailing, it is apt
to crack the first-coat of floating, and the joints of the wall arc not always easily found. The
coarse stuff for the first-coat of cornice brackets should be extra haired and carefully scratched to
give a strong foundation for the following coats of gauged stuff, which in maii\- instances is extra
thick at bold or projecting parts of the mouldings.

For large moulding and wire lathing it is best to leave the ijrackels uncoated when first-
coating the general work until the cornice running is commenced, and then to rough out
the whole cornice from the lath work with gauged coarse stuff. This gives uniform suction and
strength. If the brackets are lathed with wood, they should be first-coated with gauged coarse
stuff and scratched before the screeds are formed, so as to allow time for the lath work to settle
before the mouldings are roughed out. Weak laths frequentlj- twist b\- moisture from the first-
coating, and gradually .settle or resume their original form during the drying of the first-coating.
Leaving the lathed brackets uncoated also forms a vent for the moisture from the wall and
ceiling first-coating, thus allowing it to dry sooner. The coarse stuff for roughing out the
cornice should be gauged uniforml\- in strength and consistency, as unequal gauging tends to
cause unequal swelling in the material, con.sequently the mould is more difficult to run true.
The coarse stuff should be laid regular in thickness, taking care to graduallj- build up and
form all thick parts and projecting members with the trowel to prevent the stuff from dropping
and the mould from dragging it off, as generally happens if the stuff is laid in thick and irregular
coats. When roughing out large mouldings with coarse stuff, the members of the initres should
also be filled in and ruled fair before the running with gauged puttj- is commenced, because when
mitring, it will be more easilj- and quickly done, materials will be saved, and when finished, the
whole will be more uniform in colour.

When all the mouldings are roughed out, the plaster muffle or muffle plate, as the case may be,
is taken off, and the running with fine gauged putty commenced. The gauge board and all tools
should now be cleaned to free them from grit. A ring of putty is formed on the gauge board,
leaving the bottom of the board clear ; water is put in the ring, and the plaster quickly and
evenlj- sprinkled over the water, taking care not to sprinkle it on the putty ring. The plaster and
water are mixed together by stirring with the point of a trowel. The putty is then quickly mixed
xvith the gauged plaster by using the trowel and turning it over with the hawk. It is put on with
a large gauging trowel, or if the members are large, with the laying trowel, following the form of
the mouldings. The mould is then run along by one man, who also feeds the moulding with any
stuff that may gather on the side of the running mould. This operation is continued until all the
members of the moulding are filled out. A thin gauge of fine putty, having less plaster than the
previous gauges, is lightly drawn over with a trowel, or brushed o\cr the flat members, and thrown
with a brush for small or dry members. The mould is then quickly and steadilj' run along the
cornice from beginning to end and finished. If the moulding is extra large in girth, or a long
length of moulding has to be run, extra men are required to lay the stuff, while two may be
necessary to run the mould.

When running small mouldings, say of 10 or 12 inches in girth, one man can run and feed the
mould while his partner is laying on. When all the mouldings are run round, the running rules
are taken down, the screeds cleaned and scraped, and any holes or defects caused by nails or

Setting Out and Constructing a Corinthian Entablature.

1 1 1

patches used for the rules made good by filling up with gauged stuff. If soap, black lead, or any
other materials already mentioned are used to aid and ease the running of the mould, they should
be scraped off with a drag as soon as the cornice is run off, otherwise they will prevent the finishing
coats for wall and ceiling from adhering to those parts.

To Set Out and Construct a Corinthian Entablature.-To enable the plasterer
to set out a full-size or working drawing from the architect's design, also to comprehend the
cornice and the architrave, which are sometimes u.sed alone or as separate mouldings, their propor-
tions with that of the entire entablature arc given. The entablature and the details of the
enrichments of the coffers and modillions are shown on Plate XXIX. The whole height of the
entablature is divided into ten parts, giving three to the architrave, three to the frieze, and four to
the cornice, as shown by the first upright scale at Fig. i. This figure .shows the combined section
and elevation of the entablature. The height of the architrave is subdivided into five parts to
form its members, as shown by the second upright scale. The projection is taken from the lower
fascia, and is equal to one-fourth part of its height. As the cornice of the Corinthian order is
frequently used alone as a separate moulding, an enlarged view, with figured details, is given fsee
illustration No. i6, page 114). It is necessary that the details of the cornice .should be mastered
before proceeding with the entablature.

With regard to the enrichments of the entablature, as shown in Fig. i, the whole must be set
out and so disposed and arranged that the centre of each will be in a line with each other, or,
m other words, that they are regularly disposed perpendicularly above each other, as shown from a
to 1! (Fig. i), where it will be seen that the centres of the modillion, dentil, &%g, and other bed-
mould enrichments are all in one perpendicular line. Enrichments set out in this way are said, in
plasterers' parlance, to "principle." Nothing is more careless, confused, and unseemly than to
distribute them without any order or principle, as they are in many buildings. The centre of an
egg answers in some places of the cornice to the edge of a dentil, in some to the centre, and in
others to the space between, all the rest of the enrichments being distributed in the same slovenlj',
artless manner. The larger parts must regulate the smaller. All the enrichments in entablatures
are governed by the modillions or mutules, and distribution of these must depend on the interval
of the columns, and be so disposed that one of them may come directly over the centre of the column,
as shown in the present example at C (Fig. 2), the axis of each column.

The enrichments must partake of the character of the order they enrich. When the frieze is
enriched, the enrichment may be characteristic of the order, or it may serve to indicate the use of
the building, the rank, qualities, profession, and achievements of the owner. Having set out the
profile and the enrichments, making the running mould and running the mouldings now claims
attention. For large work the cornice and architrave are run separatel)-, the cornice being run
from a slipper screed made On the frieze and a nib screed, and the architrave from a slipper
screed made on the wall and a nib screed made on the frieze. Sections of the cornice and
architrave running moulds are shown at Fig. 4.

It may be here remarked that the nib and slipper bearings of the cornice and architrave
running moulds are made for work on ceilings and walls ; but if the entablature projects or is inde-
pendent, and supported b)- columns, the nib of the cornice mould must be cut so as to bear and run
on a nib running rule fixed on the weathering of the cornice, and the slipper of the architrave
running mould cut so as to bear and run on a running rule fixed on the soffit of the architrave.
The frieze, if plain, is set by hand ; and if enriched, a bed for the enrichment must be made by
running a small part of the bed at the top and bottom of the frieze when running the cornice and

112 Plastering — Plain and Decorative.

architrave mouldinf,'s. In this case the screed on the frieze must be set back to allow for the plate
or ground of the ornament, and the nibs and slijipers of the running moulds extended at these
parts. In setting out the mnuld plates an allowance must be made for the bed of the various
enrichments, as previouslj- described.

The ijrofiles of the three largest enrichments are indicated b)- the dotted lines. The angles of
the beds of these enrichments are spla>ed, as shown, to save fine plaster used for the cast work.
This also strengthens the top member of the architrave while it is being run. It will be seen that
an in-dentil is used in this cornice, as shown bj- the dotted line at I on the elevation. This is the
space between the face or main dentils. The in-dentil is run with the mouldings, and the dentils
are cast and planted. The in-dentil and the dentil may also be cast together in short lengths, and
then planted. In this case the running mould must be cut to form a bed for the combined dentils, as
indicated by the dotted line on the outside of the section of the running mould. The dotted line on the
section of the running mould shows the section of the main dentil. In .some examples the exter-
nal angles of the bed of the dentils are filled in with an ornament fashioned like a cone or pine-
apple, instead of using an angle dentil. An enlarged view of this class of ornament fixed in
position is shown at Fig. 1 1. The bed of the sinall enrichments is made square as sh(jwn.

When setting out the mould plate, the profile of the soffit of the corona must be taken through
the centre of the sunk panel, as shown by the shaded part at Fig. 3, thus forming the raised part
of the mould, as shown at Fig. 4.

The most intricate part in the construction of a Corinthian cornice consists in the formation
of the coffers, as shown at Fig. 2. This is a jjian of the cornice at an external angle. F is a coffer,
and M is a modillion or " block," as it is commonly called. The coffer consists of a sunk panel,
with an enrichment on the four sides, and a rose or patera in the centre as shown. A section of the
coffer is shown at Fig. 3. The coffers are formed b\' fixing a " stj-le," as from s to s (including
the side enrichments), on the sunk ]janel, so as to connect the two run plain sides of the soffit and
form two sides of the coffer. The lines in the front and back of s and .s indicate the joints of the
style before they are stopped. It will be understood that the style is fi.xed before the block is
fixed. A plan of the complete stj-le is shown at Fig. 5. When making the model of the st\-le, the
side enrichments must be set out mitred and fi.xed on the plain part of the style, and a ])erf(jration
made in the centre to act as a ke)- for the fixing stuff used when fi.xing the block. A mark must
also be made in the centre of the front of the style to act as a guide when fixing the styles. The
model of the style is moulded in wax, taking care to splaj' the back and front edges and the centre
perforation, also the mitres of the enrichments, to allow the mould to draw in one piece. These
parts are trimmed square after the styles are cast. Having fixed two styles, the front and back
parts of the coffer enrichments, as shown at Fig.s. 6 and 7, are fi.xed ; then the patera (Fig. 8) is
fixed; and then the joints of the stj'les are stopped, which completes the coffer. This done, the
block (Fig. 9) is fixed, and then the small enrichment (Fig. lOJ is fi.xed, thus completing a part of
the soffit of the corona. The (jther parts are of course made and fixed in a similar way, but the
positions of the coffers and blocks must be set out on the whole length of the cornice before the
fi.xing is commenced.

Setting out coffers and blocks is a simple matter, j-et it requires care to ensure accuracj-.
First fix a coffer and a block in each mitre, as show n at the external mitre (Fig. 2) ; then from the
centres of these blocks set out the whole length of the cornice. This is best done by measuring
the full length of the cornice from the mitre blocks, and dividing the total by the combined width
of one modillion and a coffer, and if there is no remainder, the combined width is marked on the

Plate XXIX.

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Elevation of Corinthian Entablature and Plan ok Cornice at External Angle.

Setting Out Coffers and Modillions.

soffit ; but if there are a few inches over, they are divided amon<j the given number of blocks.
The marks are proved by going over them with a compass or a wood gauge. When the exact
positions of the centres of each coffer with the block are ascertained, the marks are extended across
the corona and down the plain member on which the back end of the block rests by the aid of
a square. These extended marks or lines gi\-e the centres for fixing the stj-Ies of the coffers and
the blocks. Fixing the coffers and blocks is the ne.Kt part of the process. This being done, as
already described, taking care to use the centre mark on the coffer as a guide for fi.xing it fair
with the centre lines on the soffit, and using a wood square to prove the square of the style, also
using the edge of the square to prove the le\el of the coffer with the run sides of the soffit, then
clean off any e.xcess stuff that may e.vude at the keyhole and edges of the style. After this the
back and front side enrichments are fi.xed, as already mentioned. Before fixing the ])atera; a
keyed or undercut hole must be cut in the sunk panels to gi\-e a key for the stuff that is used for
fixing the pater.ne. A corresponding keyed hole must also be formed on the back of the patera;.
This is best done by making the desired size of sinking in the model of the patera before it is
moulded. These sinkings must be undercut after the paterje are cast.

The model of the patera is generally moulded with a front and back waxed mould. For large
pateraj, or those having a deep projection, a piece of twisted galvanised or copper wire, sufficiently
long to enter the ke}'ed holes in the patera and the soffit, should be inserted in the fi.xing stuff
when fixing the pater.TE. This method should always be adopted where the bedding surface of the
patera is small, so as to enable it to resist the weight of a brush while being painted or gilded.
If the patera; are extra deep, and project below the line of the soffit, they should be fi.\ed first,
otherwise they are liable to get disturbed when fixing the blocks and other enrichments.

The modillions should be fixed with stiff gauged stuff for the keyed holes in the styles, and
the corresponding holes in the blocks (which are made while being cast), and using softer gauged
stuff for the bedding surface of the block. After the fixing stuff is laid, place the block in position,
and work it gently but quickly from right to left, so as to force the excess stuff out, and obtain a
true and solid bed, taking care that the centre of the block is linable with the centre mark on the
soffit, and using a square to prove the squareness of the block, and then clean off the excess stuff.
The small enrichments (Figs. 6, 7, and 10) are fixed with soft gauged stuff, so that they can be
easily and quickl)- fixed. Small cast work of this kind should always
be fixed with soft gauged stuff, as there is very little weight to carry
until the stuff is set. The suction alone between the two bodies is often
sufficient to support the cast until the stuff is set. These small en-
richments are moulded with a face or front wax mould.

Modillions or blocks were formerly cast in three parts, namely, the
body, the main part of the leaf, and the tip or curled end of the leaf;
the body being cast in a wax piece mould (sometimes a plaster piece
mould), and the leaf and its tip in a front and back wax mould, but now
the complete block is generally cast in one piece in a gelatine mould.
The body of the block may be cast in a gelatine mould, but where the
back section of the leaf is clear or awa\- from the block near the scroll end, as shown in the accom-
panying illustration, and .seen in fine old buildings, the leaf should be cast and fixed separately.
An enlarged view of the plan and side elevation of a modillion is shown in illustration No. 15.
The bed moulds and the other small enrichments in the entablature are generally cast in wax
moulds.

Monn.i.iON.

114

Plastering — Plain and Pccorafi'i'c.

When fixing the enrichments in an entablature, take special care that the)- all " principle "
with each other as already mentioned, thus forming a pleasing and artistic finish, which is charac-
teristic of well-designed mouldings.

T(i Skt Out a Cokintiiian Cokxick. — The members which arc enriched in the cornice,
shown in the preceding plate, arc drawn as plain members on this cornice so as to show the profile
and method of setting out more clear.

The combined elevation and profile of the cornice shown at Fig. i, in the accompanj-ing
illustration. No. i6, is an enlarged view of the cornice of the Corinthian entablature. The first

f STale Jy"

No. i6.— Corinthian Cornice.

upright scale contains four parts of the ten into which the whole entablature is divided, as on the
preceding plate. The second .scale is divided into five parts, the third of which goes to the
modillion, the fourth to the corona, the fifth to the cymatium ; the first and second together are
divided into three parts, the first for the reversed cyma at the bottom, the second for the dentils,
and the third for the ovolo. The smaller members are in jjroportion to the greater, as shown by
the smaller divisions on the scale. The modillions are l of the diameter of the column, and their
distances two sixths and a half Haifa diameter is divided on the corona at Fig. 2 into six parts,
of which the width of the modillion is two, and the length of it is four. The cap projects J of those

Mitring. 1 1 5

parts, atitl the distance between the modillion.s is five. By this rule the exact distance from centre
to centre of the inodiliions is yS. of the diameter. The dotted hne AC answers to the diminished
part of the column, from whence the cornice is projected ; the projection being equal to its height,
is divided into four parts, as shown by the scale at the bottom of the cornice. One-fourth of this
scale is divided into si.x parts, as shown at C, five of which give the width of the modillion. The
distance between them is in proportion to it as figured at I'ig. 2. The fillets, F F, of the modillion
are \ of its width, and so is the bead, B. The position and size of the sunk panel are indicated by
the dotted lines in the corona at Figs, i and 2, the size being obtained as shown by the figures in
the dotted spaces. The width of the dentils, D, is obtained by dividing the semi-diameter of the
column marked on the corona at Fig. 2 into fourteen parts, two of which give the width of the
dentil, and one the space between them. This space of course is also the width of the in-dentil,
the height of which is one-fourth of the height of the main dentil, as indicated by the small division
on the inner side of the second upright scale,

The centres and radius for describing the profiles of the cj-matium or cyma-recta, the ovolo,
and the inverted cyma or ogee members are indicated by small crosses and dotted lines.

Mitring. — Mitring is looked upon by the generality of plasterers as a test of speed and
ability. As they generally work in pairs on other portions of the work, their individual ability is
not easily seen, but when mitring a man carries the operation through alone. Mitring being
done by hand, is a near approach to modelling, and is an operation of which a dexterous and good
plasterer is naturally proud. The quality and time required for mitres greatly depend upon the
degree of hardness of the run cornice, also upon the suction. A mitre can be more freely worked
and more e.xpeditiously done on a hard cornice surface, and where there is a suction. The extra
absorbing powers of brick walls as compared to lath partitions cause the gauged stuff to get firm
sooner, and enables the mouldings to be more readily blocked out before the stuff is set. A common
error when mitring is gauging the stuff stronger than that which has been used for the running of
the cornice, causing extra swelling and difficulty of ruling the members over, and cutting the run
part of the cornice with the joint rule, especially if the stuff sets before the plasterer has had time
to rule all the members over, and then being stronger, and consequently setting quicker, he has
not so much time for forming the members. Ordinary-sized mitres can be done with one gauge by
using less plaster than in the gauge for running the cornice, and stiffening the greater portion with
dry plaster, and using this for roughing out the mitre ; then using the soft portion left for brushing
over the members and filling up all holes, and afterwards working the joint rule over the metal to
take the superfluous stuff off. Should the mitre not be fine enough, the gauged stuff can be further
softened on the hawk by adding water, and working it with the gauging trowel, brushing the soft
or creamy stuff all over the mitre again, then working the joint rule again. Small members, and
those at the top and bottom of the cornice, where there is most absorption, should be worked by
the joint rule first, leaving the large members, drips or coves, or where there is a large body of stuff,
to be ruled over last. The joint rule should always be worked horizontalK', especially when dealing
with beads and cavettos. Drips and large members should be worked with the joint rule with an
upright motion, because if worked down, the stuff may be pulled down. ]\Iitres should not be
worked, fined, or tooled with small tools, as they can and should be brought to a good and straight
surface by the proper use of the joint rule. Small tools should only be used for laying the stuff
where required, and cleaning out the intersections of the mitres, quirks, and for stopping. A square-
ended small tool may be used for smoothing flat, straight surfaces. Returned mitres and short breaks
are "run down," then cut to the required lengths and planted. They may also be mitred by hand.

ii6

Plastering — Plain ami Decorative.

iMlTKE- Mould. — V'arious attempts have been made to construct a runiiiiii( mould that would
form the mitres simultaneous!)' with the cornice running. Most plasterers will have heard of, and
some may have tried to make and work a mitre-mould to save liand labour. Those who have
tried it will have found the results far from satisfactor)-. The subjoined illustration (No. 17)
shows the method of setting out and constructing a mould intended for forming the moulding and
mitres in one operation. The mould is made by fixing the metal plate at an angle of 45" on the
slipper, or in other words fixing the iron plate at one angle of a square slipper, w hich allows the
mould to run nearly u]3 to the angle, one face of the slipper being u.sed for one side of the wall,
and the other face at right angles being used for the other side of the wall. Fig. I shows the
method of setting out the profile of mould. A is a given section of a moulding, and i; is the section

of the moulding at the mitre. ' To
obtain this, first draw the moulding
A full size, and then extend the
ceiling line and draw another wall
line. Then from the projection of
the top member draw an angle
line at 45 . Carry up the pro-
jections of the various members to
the angle (or mitre line), and then
draw horizontal lines from the
\arious members ; also centre lines
of large members as from a to /
(the vertical letters). Take off the
lines a to /(diagonal letters) on the
angle line, and set them on the
ruling line from a to I (horizontal
letters), and then laying them down
to the horizontal lines, the inter-
sections give the profile, for the
mitre-mould.

Fig. 2 shows a side elevation
of the mitre mould, and Fig. 3
shows a front elevation. It will
be seen that the mitrc-mould is
an expensive and unsatisfactory fad. The time expended in setting out the elongated members,
making an extra mould, and cleaning out the intersection by hand (as the mould does not leave
a fini.shed mitre), also making good the parts broken by drawing out the mould from interlocked or
undercut members in the moulding, is not repaid. An average plasterer would put in all the
mitres of an ordinary-sized room while the mould was being made. The mould will only run
into every second angle, and must be taken off and reversed to fit the next. It may seem a waste
of time and space to de.scribe and then .show the utter usele.ssness of a mitre-mould, but having
met man>- plasterers who stated that they had used or had seen a mitre-mould that worked
wonders, 1 am constrained to give a description, not only to save future futile controversy, but
to show that in this book the much-debated trade subject has not been omitted. In concluding
this subject, it may be stated that not any one of the mitre-mould plasterers would or could

No. 17. — MrrRE-MouLi).

Fixing and Mitring Enrichments. "7

practically explain the inodiis operandi of this mysterious mould. A description and illustration,
by Mr T. Drake, of a mitre-mould, on the same principle as here given, appeared in The
Builder, 1S48. The mould is taken off at the centre of the length of the cornice, and then the part
broken by the mould made good.

Fl.KiNG Enrichments. — Enrichments should hz fi.xed straight, square, plumb, and firm
Cornice enrichments, such as bed moulds, friezes, &c., for which a bed or sinking to receive them is
formed by the running mould, do not require such strong gauged stuff as soffits, modillions, or
other hanging casts. For light enrichments the gauged putty and plaster should never be stronger
than that used for the cornice, and clean strong size water should be used. This gives m(jre time
for fixing a number of casts, and improves the cementing force. The bed for the cast work should
be scratched, dusted, and wetted before the cast work is applied. A small portion of fine plaster
(the same as used for casting the enrichments) should be gauged with clean size water, to be used
for the joints. The gauged fixing stuff should be spread evenly over the back of the cast and over
the scratched bed of the'moulding. No more should be laid on than will fully fill up the scratches.
Then place a small piece of the white or joint gauge on the joint, and press the cast into position
by gently but quickly sliding the cast twice or thrice backwards and forwards to expel the air and
incorporate the two bodies. It is a mistake to dab a lump of gauged stuff at random on the back
of the cast and press it on the bed, as the stuff does not properly enter the scratched part of the
bed, and the contained air prevents proper cohesion and solidity. When too thick a coat of stuff is
laid on the cast, straight and even fixing is more difficult. The excess stuff oozes out at the sides,
and unless time and care be taken in cleaning it off, the moulding, or cast, or both, get damaged.
A small portion may also ooze out in the first method, but it will be so thin that it can be brushed
off while soft. When fi.xing modillion blocks or trusses, a dovetailed hole should be cut in the
vertical and horizontal parts of the bed, and similar holes in the blocks (which are made when
being cast) are filled in with gauged stuft" and applied in position. If the cast should be very
heavy, or of Portland cement, it is further secured by inserting a slate or iron dowel while the stuff
is soft, allowing a portion of the dowel to project to enter into the body of the cast. Heavy casts
should be temporarily supported by wood props until the fixing stuff is set. When fixing heavy
casts, the plain surface of the plaster work should be cut as far as the lath, to obtain a better and
stronger key. The putty in the fixing stuff should be mixed with long strong hair or tow, as
described for rib mouldings or ceilings. Hair or tow may also be used advantageously in fixing
Portland or other cement work. Cast work, when extremely heavy, should be further secured by
means of long screws or bolts, placed so as to pass through the cast work and into the timber, the
casts being bedded with gauged haired stuff, and temporarily propped up. The screws or bolts
should be fixed before the stuff is set, to avoid the probable disturbance of the gauged bedding.
Before fixing any cast work, they should be placed in position to prove their correct fitting.
Centre, side, and end lines should be made on the surface of the bed to give a guide for fixing. It
may be necessary to fix nails at intervals in the lines to give a further guide.

Mitring Enrichment.s. — Before fixing continuous or space cast work, the length and
width of the panel or room should be set out to prove that the mitres are equal-sided, balanced,
and have flowing lines. Nothing looks so slovenly or unworkmanlike as a mitre in an ornament
cut haphazard, with the leading stem disjointed, or springing out of a flower or tendril. If the design
is vertical, say a bed mould or frieze with an alternate leaf and husk, what can be more offensive
to artistic taste than a part of the leaf on one side and a part of the husk on the other side of the
mitre I There is no excuse for this want of taste and wanton treatment. A little time expended in

liS

P/nsfcriiig — /Vail/ and Decorative.

scttiiifi out the work will obviate these defects. Where there are no shrinkini; and stretching casts
the mitres can be eased by stretching or shrinking the cast work at the joints. Stretching or
shrinking are evils, and it depends on the design of the enrichments which of the two is the less,
but in most instances .shrinking is the greater evil. Shrinking does not require so much labour to
make the joints good. Stretching does not show quite .so much, espcciall)- if the j(jinl is well
modelled and of the .same colour. It also gives greater scope and freedom. It has already been
mentioned that in good shops the breaks or other short lengths are set out in the shop, and that
there are stretching and shrinking casts and mitres modelled and made to facilitate the formation
of good mitres. This latter method is certainlj- the cheapest and most satisfactor_\- in the end.
The setting out is best done by cutting a lath as a gauge to the length of the cast, and marking the
length of each cast temporarily on the bed of the cast work from mitre to mitre. When the mitre
has been determined on, and the casts set out to come in, the marks are made more distinct to give

Xl>. 18. — I'KIE/.E, I'ALACE CHA.MHEKS, LONDO.N. \V. Mll.I.AK, iS/j.

a guide for fixing each separate cast as required. It is better to measure thrice than alter twice.
Space ornaments .should also be .set out accurately, but there is no difficult)' in the mitres, as the
intervening space between each cast can be increa.sed or diminished as required.

When fixing modillion blocks, dentils, or paterae, the mitres should be fixed first, and then
the spaces and positions set out. Special care must be taken when mitring enrichments with dis-
tinctive vertical parts, such as figures, or pendants of flowers or fruit in friezes, that the cast work is
not unequal!)' or irregularly stretched, so as to enable them to come to an equally balanced mitre
at the angles. Where there are no stretchers, the cast work should be cut between the main vertical
parts, so that the joint on each side will be equal, or, in other words, that the vertical parts will be
equidistant from the main or other parts when fixed. The same remarks applj' to shrinking. The
annexed illustration (No. 18) is a portion of a frieze consisting of a swag of flowers and pendant of
flowers designed and modelled b)' the author for the Coffee Room, Palace Chambers, Westminster,
London, and is now used to illustrate the above. From .\ to li is the length of the cast. It will be

Piizsri)/e.

119

:EU

i»-

7^.

:L-

H "

■■^■^'■"■v

seen that if the joint was kept ojjen for stretching purposes, or cut for shrinking purposes, that it would
form an unsightl\- and unequally balanced joint, whereas if cut true between the vertical part (or
flower pendantj and the main portion (the swag of flowersj, as shown by the joint at A, the joint
can be stretched or shrunk equally on both sides. Another way is to mould and cast the swag
separate, also the flower pendant, as shown at U. This was the method adopted for the above job,
where there were a large number of mitres and bays to contend with ; and in addition to this, a
stretcher of the swag part was specially made, so that all the mitres were alike, a flower pendant
being in each external and internal mitre.

The mitres of running enrichments, such as soffits, &c., are made up with bands or ribbons,
which are cast or worked in situ b\- hand. The latter way is the quickest and most artistic.
Another plan is to fix paterte or drops at the internal and external mitres. The scroll work of the
enrichment is then formed to spring from the patera, and finish at the patera at the ne.xt mitre.
Sometimes the inner member at each side of the soffit is worked across at right angles at each
mitre, thus forming a small square sinking or panel, which is then filled in with a patera or drop.

Bed moulds, such as an egg and dart, have internal and external mitre leaf modelled and cast.
This is a neat and quick way of forming mitres. A good cornice, with well-modelled and effective
ornament, may be disfigured and
spoiled by careless mitring, yet
it is as easy (and in many cases
more so) to make good and
satisfactory work. It is there-
fore best to set out correctl}-,
and make sure of a correct
finish before beginning to fix.
Illustration Xo. 19 shows the
method of mitring various forms
of fret enrichments. E.xamples
of cast mitres are given in
Chapter X.

Pugging. — Pugging fin
Scotland called deafening) is a body of plastic materials laid on boards fixed between the
joists of a floor, or lath and plaster partitions. It is intended to prevent .sound and smells
from passing from one room to another. Pugging is generally performed by laying a thick
coat of coarse stuff on a foundation of rough boards on fillets, which are nailed on the sides
of the joists. Chopped haj-, straw, or ferns, mi.xed with lime, is sometimes used for the plastic
coat. Coarse plaster, with and without reeds, is also used in some districts. Sawdust is
sometimes substituted for reed.s. In Scotland, pugging is done by forming a foundation with
thick rough lath wood. On this a coat, about h inch thick, of coarse stuff" is laid, and when dry,
a layer, about 2 inches thick, of dry ashes or lime riddlings is deposited on it. The upper surface
is then sprinkled with water, and finished with a coat of coarse stuff. This makes sound proof
work, but in the event of subsequent damage or alterations, the dry ashes run out, causing further
dust and damage. In some instances the dry ashes are gauged with lime. When laid, the upper
surface is beaten and smoothed with a shovel. This makes sound proof and durable work,
impervious to vermin. Partitions are deafened by lathing between the studding, and then laying
on a coat of coarse stuff. When dry, the partition is lathed and plastered in the usual wa}-.

No. ig. — Frf.t Ornaments, showing their .Mitres.

'20 Plastering — Plain and Decorative.

Pugyinsj slabs of fibrous plaster arc now largely employed. They have the advantage of being
light and drj*, and are rapidh- fixed.

Sound Ceilings. — No lath and plaster ceilings can be made sound and free from cracks
unless the joists are well seasoned, firmlj- fi.\cd, and sufficiently strong to carrj- the overhead
weight, as well as sustain the weight of the lath and plaster, and resist jarring. Ceiling joists
should never be more than i:: inches apart from centre to centre. Where double lath is used,
the joists may be 14 inches from centre to centre. Good laths, with break joints every 3 feet, and
well nailed, are also imperative. If the above dimensions are exceeded, the laths are liable to
give or twist, on account of the weakness of the laths, or the weight of the plaster, or both
combined. If the joists exceed 2 inches in width, they should be counter-lathed or strapped,
to ensure a kej- for the plaster. Wiiere it is impracticable or inconvenient to fix the ceiling joists so
clo.se, they should be brandered. This strengthens and stifiens the joists, also gives a free kej*
for the plaster, and forms a .sound level ceiling.

Brandered or strapped ceilings are done by nailing wood straps or fillets <icross the under
side of the joists. The fillets are from li to 2 inches square, and are fixed from 12 to 14 inches
from centre to centre. The sizes and distance apart varies according to the thickness of the lath
and the class of plaster work. Brandered ceilings are largely used in Scotland, and make good
sound ceilings.

Cr.\cki:d Pl.vster Work. — Cracks in plaster work are due to various causes. The\' may
act individually or in combination. Cracks are often caused by settlement in the building. These
cracks may be easily discerned by their breadth, depth, and length. They also arise from the
shrinkage of bad or unseasoned timber used in the construction or framing of the building, which
may cause displacement in the joists or the laths. Cracks are sometimes cau.sed by the laths
being too weak, or by too much plaster being laid on weak laths, or too little plaster laid on
strong laths. Other causes are the too sudden drying of the work ; strong winds or heat ; the
laying one coat of mortar on another coat, or on walls that have a strong suction which absorbs
the moisture or " life " of the coat being laid, when it becomes .short, or crumbly, scaly, and apt
to peel or fall off. In this last ca.se it does not set, but only dries and .shrinks, which gives rise
to cracks, and eventually falls or crumbles away. The use of bad materials, insufficient use of
lime and hair, or scamping of labour is often followed by crack.s. Insufficient labour and unskilled
workmanship in the application of the materials is a great source of trouble, but it will be under-
stood that the best quality of labour will not make bad materials good and strong; and, on
the other hand, the best materials will not compensate for bad labour. It is only by judicious
selection of materials, and their skilful manipulation, that a high and enduring class of work can
be obtained.

Rki'.MRING Old Plastkk. — Repairing is also termed "patching," "jobbing," and "making
good." When repairing or making additions to old plaster work, care should be observed in cutting
the joints, so that the key of the existing work is not injured or broken. The joints one way should
be cut on the studding or joists, and in a line with the laths the other way. A joint at the edge
of a lath is stronger than at the centre. If the lath work is weak, the joints should be cut
diagonally. Never use a hammer to cut joints on lath work, for the repeated impacts will weaken
and crack the old work. If the old plaster is hard, cut the joint with a saw, or with a hammer and
chisel, and finish with a strong knife. Avoid acute angles in patches. Square, round, or oval
patches not only look better, but are much stronger than zig-zag ones. Having cut the joints
neat and square on edge, and then repaired the old lath work, brush the joints and the laths with

Repaiyiiig Old Plaster and Gauged Work. 121

a dry broom, and then wet the joints, but only damp the lath work, as excessive water tends to
warp the laths. The joints are sometimes painted to prevent damp from extending to the old
work, or causing injury to any surface decoration. Gauged coarse stuff is generally u.sed for
roughing out, and gauged putty for finishing ordinary work. The coarse stuff is generally gauged
with coarse plaster. For small patches, the whole thickness is generally brought out in one
coat ; but for large patches it is best to lay a first coat, and then scratch it in the usual way. If
time permits, this should stand for one day, or even two, to allow the lath work to settle. The
stronger and stiffer the gauge, the less power the laths will have to warp. The floating coat is
gauged moderately stiff with coarse plaster, or with fine plaster and coarse in equal proportions.

When laid, the surface is ruled in with a straight-edge, keeping it within the line of the old
work to allow for plaster swelling, and a thickness of yV inch for the finishing coat. It is often
necessary to drag the surface down to allow the finishing coat to be ruled fair and flush with the
old work. The surface should be left fair but rough. Gauged work should never be scoured,
as it only kills the plaster, and therefore weakens the body of the material. The putty for the
final coat should be gauged with fine plaster and a little size water. After being laid, the surface
is ruled flush with the old work, and when firm it should be smartly trowelled off, and finally
finished with a semi-wet brush. The joints should be trowelled flush and smooth, and the old
part brushed to free it from an\- gauged stuff All rubbish should be damped as it falls, and
removed as soon as possible to prevent further dust and dirt.

Parian or other white cements are used for best work, or where time is a consideration. All
white cements having plaster for their basis are manufactured to be non-efflorescent, non-porous,
durable, free from liability to unequal shrinkage (which causes cracks), and free in working. They
form admirable materials for repairs or additions. When making good old or broken lime plaster
work with any of these cements, the joints and lath nails must be painted with red lead, quick-
drying paint, or with shellac. Galvanised nails ought to be used for the lath work where these
cements are to be used. Small holes and cracks are usually stopped with fine plaster gauged with
putty, or better still, putty water. Parian cement is also used for a similar purpose. The holes and
cracks should be brushed with Parian solution before the stiff Parian is applied. This solution is
simply fine Parian gauged to a thin creamy consistency with water. New or damp lime-plastered
walls can be painted or papered much sooner, and with greater safety, if brushed with a thin Parian
solution. It is also useful for stopping the suction on dry floating and fibrous slabs before laying
the final coat. Several of the new patent plaster and white cements are well adapted for repairs, or
where time is limited.

G.\U(;ed Work. — All gauged work should be regulated in strength according to the purpose
required. A brick or stone wall would not require so much plaster as a lath partition. Work not
subject to friction or wear does not require so much plaster. If the work is required for immediate
use, as with running screeds, or blocking out large mouldings, or fixing large castings, much plaster
must hz used. The amount of plaster required for scaffold work varies from \ to equal proportions
for gauging coarse stuff or setting stuff, and from \ to equal proportions for coarse stuff" for heavy
cornices, and \ to equal proportions for putty and fixing ornament. The amount of plaster also
depends upon the quality of the plaster, some of which are much stronger than others. Coarse
plaster that is of a dark and sandy nature is generally weak, sets quickly, and becomes soft and
useless. Fine plaster should be used for gauging putty when running cornices, also for fixing enrich-
ments. All gauged work should be gauged with uniformity, each separate gauge having the same
amount of water and plaster as required for the bulk of stuff" being gauged. Unequal gauging

>-- P/nsteriiig — /%//// (Did Decora the.

causes hard and soft places in the work, and when moie plaster is used in one i^au^'e than another
there is an extra expansion caused by the swelling of the plaster, which makes the work more
difficult to do when floating, setting, running mouldings, or mitring.

A quart and a jjint measure should always be kept on the scaffold for measuring the water
used for the various gauges. The quantit\- of water will regulate the quantit)- of jjlaster for each
gauge. A proper plaster box should also be on the scaflbld, made to hold a sack of plaster, and
having a lid made in two halves hinged from the centre. This prevents the plaster from getting
dirty by falling stuff, and from getting damp hy absorption from the atmosphere. Where there is
a large quantity or continuous gauging, the bo.K should be jilaced on a stand this is called a stand-
box) to prevent unnecessary exertion and loss of time b\- stooping for each handful. A
"stand-box " is illustrated in Chapter XXI.

When gauging coarse stuff for large surfaces which require several gauges to complete the
work in hand, size water should bo used in proper proportions with the neat water used for gauging,
so as to allow suflicient tiine to pro[)crl_\- manipulate the material. This also allows the \arious
gauges to be laid on or against the previous ones while they arc in a soft state, thus forming
stronger joints and better cohesion between the various gauges. In the event of gauged stuff
setting before the work is laid and ruled off, it is difficult to make the surface strong and fair. The
use of size water in gauged setting stuff and putty enables the work to be freely trowelled and
finished. Gauged stuff should not be hand floated, as excessive working destroys the setting powers
of the plaster.

Joist Lixe.s <jn Ci;ii.ing.s. — Common flat ceilings show in time the precise position fif the
joists above, and in many instances the position and form of the lath work can be easilj- discerned.
Many theories have been advanced as to the cause of these unsightl}- lines or marks, which arc so
distressing to the mind and eye. In xny opinion they are due in a great measure to insufficient
material and inferior work. The plaster which is between or separate from the joists is more
pervious to the atmosphere than that which is in more direct contact. The air in passing through
leaves behind it particles of dirt assigned in larger measure to the unattached than to the attached
portions. Dust that finds ingress between the joints of flooring boards lies on the unattached
portions, consequently the joists show themselves as lighter lines on a more or less dirtj- back-
ground. The same causes apply to the lines on the lath work. Another cause is that the plaster
work is too thin. In many instances the floating is brought up from the lath in one coat. This is
a most pernicious habit, as it is not only the cause of lath lines, but the ceiling invariably cracks,
and develops spontaneously quite original patterns indicative of rivers, which too often lead like
Niagara to a catastrophe in the form of falling plaster. Joist and lath lines on thin ceilings may be
partly obviated by laj-ing strong brown paper over the upper side of the lath and plaster and then
pasting the edges to the sides of the joists, so as to form a cover to the plaster work. The better
and most sanitary way is to lay the work in three coats, allow the first coat to drj-, consolidate
the floating coat by well scouring with a hand float, and render the setting coat hard, non-
absorbent, and impervious to air by thorough scouring, trowelling, and brushing.

CHAP T E R \\
DECORATIVE CEILINGS.

Historical— Panelled, Figured, and Ribbed Ceilings— Rib Brackets and Lathing— Floating Panelled
Ceilings— Setting Out Panelled Ceilings— Panel Mouldings— Coffered Ceilings— Planted
Panelled Ceilings- Setting Panelled Ceilings— Hard Finish— Fine Finish— Cement Finish-
Portland Cement Ceilings— Fibrous Plaster Panelled Ceilings— Working Plans of Panelled
Ceilings in King Charles' Room, Winton, Careath House, and Beeslack — Panelled Ceilings at
Edinburgh, Throne Room, Holvrood Palace, Liverpool, Bradford, Dublin, Forfar, and
Glasgow— Gothic Ceilings— Modern Gothic Plasterers— Gothic Ceiling at Toddington —
Groined Ceilings— Groined Ceiling at Trinity College— Jack. Template for Gothic Ribs —
Spike AND Rope Bracket— Mitring Rib Intersections— Old Gothic Materials— Classic Panels.

Historical. — The use of plaster as a covering and smooth surface finish for walls and ceilings is
conducive to health and comfort, and gratifying to the eye. Ceilings afford great scope for
decoration, yet it seems a strange defect in our modern method of decoration, that in many
mansions the walls of the principal rooms are highly decorated with e.\pensive papers, to be
afterwards partly or wholl}- covered with pictures, looking-glasses, and bric-a-brac, and the floor
is covered with carpets, to say nothing of furniture ; but the ceiling spreads its broad blank waste
of white above us, expressionless and inartistic to a great degree. The ceiling being the crowning
glory of a room, and the part most seen, should be decorated with form and colour.

It is true the ceilings are whitewashed, but the same monstrous monotonj- pre\-ails all over the
house, from the basement to the attics. The cellar, sculler)-, and passage ceilings are treated on a
scale of equality with the ceilings of the principal rooms in the house. XMiitewash is an excellent
material in its proper place, but not in the best rooms, as it is washed off and redone at short
intervals, and besides the annual cost there is the additional injury to one's feelings and furniture.
Whitewash should be entirely dispensed with, as being disastrous to decorative plaster work. It
gradually blunts and blurs the arrises, lines, and shadows of mouldings. It clogs and obliterates the
modelling and outlines of ornament, and after repeated washing off and renewing, finally destroys
and renders the plaster work a distorted, unmeaning, and unrecognisable mass. If whitewash must
be u.sed on moulding, from a want of knowledge or from immediate but false economj-, let the
plaster have two coats of thin oil paint. The whitewash, when dirt}-, can then be washed off with
less injury to the surface of the plaster. Some whitewashes, also wall papers, are objectionable from
a sanitar)- point of view, because thej- are absorbent, and the size, glue, or paste used in their
working are more or less deleterious. Painting plaster work at an extra first cost is cheaper in the
end. It hardens the surface of the plaster, prevents absorption, and can be periodicall)- washed
with less mess and more speed than whitewash. It is also not so readily affected or spoiled by the
injurious impurities of gas. It seems inconsistent to concentrate time and money on expensive
wall papers, and surmount it with an abrupt top finish in the form of an elaborate plaster cornice,
and leave a broad bare expanse of ceiling surface.

A little time and thought may be wisely and advantageously devoted to the decorati\ e part of

124 Plastering — Plain and Decorative.

ceiling plaster work. The matter of expense is small if the after and lasting artistic effect is taken
into consideration. Nothing catches the eye so quickly as a graceful and well-designed ceiling, with
the rib moulding well defined and forming geometrical panels. The panels or moulding may be
relieved with appropriate foliage, and the introduction of the owner's monogram, date of building,
or other desired devices. Kconomy of decoration is nowhere to be so much deprecated as here, as
a large barren space of white ceiling has a most heavy and oppressive effect ; the contrary being the
case where a ceiling is artistically decorated w ith neat and well-balanced mouldings, panels, and
artistic ornament, and afterwards painted and relieved with gold judiciously applied.

As there seems to be a growing tendency towards the rcintroduction and use of decorative
plaster ceilings by modern architects of culture, it is desirable that plasterers should have a thorough
practical knowledge of the art of this beautiful branch of their craft. The illustrations herein will serve
to demonstrate what plasterers were capable of in the jiast in design and execution. I believe that
there are good practical plasterers and artistic modellers at the present day able to carry out the
same class of work if opportunities were offered, and that if there were a demand the supply would
soon follow. The subject of ceiling decoration is so interesting and extensive, that to do it justice
it would take a special book, full of illustrations. It would be worthy the attention of some of our
city and art bodies to afford opportunities to plastic art students to collect sketches and information
of the many fine examples to be found in the three kingdoms.

One of the most important and beautiful parts of plastic art is the decoration of ceiling.s. In
the reign of Edward VI., the English plasterer had rapidly learnt the art and was largely occupied ;
and almost every house of importance erected during the reigns of Elizabeth and James I. was
adorned either internally or externally, and often both, with his work. Not educated to the highest
branch of the plastic art, he generally avoided figure work, and took refuge in geometric pattern.
Nor was this without other reason, for the lowness of our rooms required a less ambitious treatment
than did the lofty salons of France and Italy. The fan tracery of the Late Gothic of Henry VI I. 's
time afforded them an excellent starting-point ; and its radiating ribs and pendentives, such as \-ou
see at King's College, Cambridge, Oxford Cathedral, Henry XTII.'s Chapel, and in much other
Perpendicular vaulting, offered an excellent suggestion. It readily lent itself to the subdivision of
the ceiling into squares of lozenges, and circles abounded, many of the arrangements being equally
beautiful and ingenious ; but rarely were large figure subjects introduced amongst them, small
emblems, armorial bearings, and personal devices being used to fill up the voids of the geometric
pattern. Gradualh' the size of the subdivisions increased, until it became the practice to divide the
room into four quarters, and no matter what their size, unless they were long galleries and corridors,
the patterns occupied a quarter of that space reversed. This made half the room, and that half
doubled completed the design. The enlarged cartoon thus obtained led to the abandonment of
merely geometric pattern, and soon lines of wondrous device took possession of the ceiling —
involved, contorted with quaint unexpected quips and cranks, a true parallel, in fact, to the
moderate magnitude, as in the "Watching Chamber" at Hampton Court ; Red Lodge Park, Bristol;
Stockton, Wilts, Crewe, and all over the countr)-; and not even when the rooms were ceiled between
the main beams, in order to gain height, did this trabeation prevent the adoption of this quasi-Gothic
treatment.

This pendentive system outlived the radial tracery form from which it sprung, though the
radial root form often exists on pendants, even when there are no correlative ribs on the ceiling.
The geometric arrangement of the ribs soon became infinite — interlacing quatrefoils, squares, quaiiitl}-
involved diction of the time.

Decorative Ceilings.

12;

In the earlier ceilings these ribs were plainly moulded after the manner of groin ribs. As the
power of execution grew, the}- had flat surfaces often ornamented b)- impressed ornament, run on
by a revolving stamp like a bookbinder's tool, with here and there a bossage of higher relief from
a wooden matrix, fashioned like a butter stamp. These ribs have moulded edge and hand-wrought-
bosses at their junction, producing an exceedingly rich effect. It has been suggested they are
borrowed from Continental sources, but there is no evidence of plagiarism, and there are radical
differences between the Renaissance of England and that of other countries sufficient!}- marked to
enable us to distinguish them.

Again, plastered ceilings were not common in the countries whence these designs came, wooden

ones being chiefly in use there. It is probable, therefore, that our master workmen had their own

album of designs, and travelled about the country with them, frequently repeating them. They do

not seem to have often published books of designs in this country at that date, though in 1615

Walter Geddes published " Sundry Draughtes principally serving for Glaziers and not impertinent

for Plasterers," giving outline diagrams of geometric forms ; but be}-ond one or two of the most

obvious ones, nothing identical can be traced in the executed plaster work. If the character of our

ceilings had resembled those of other countries, they would not have so e.xcited the admiration

of foreign visitors. The Duke of Wurtemburg, who visited England in 159S, expresses himself

astonished at their richness and beauty; and Sir Henry Wotton, King James' Ambassador to

Venice, where stucco work abounded, whilst recognising the good use we made of it in our

ceilings, urges us to make larger use of it for figures, for " plastique art," says he, " is not under

sculpture, but very sculpture itself, but with this difference, that the plasterer doth make his figures

by addition and the carver by subtraction," quoting the Italian use of it for "mantling of chimneys

with great figures." Of such stucco mantels there are some examples in England, but it chiefly

maintained its swa}- on our ceilings, with frequent external pargetry between the timber framework.

In the early part of Charles I.'s reign the same principle of design continued, but towards

the latter part of it the influence of Inigo Jones and Rubens was decidedly detrimental to the stucco

workers. The Palladian character of the architecture, and the trabeated and coffered ceilings of the

architect, led to the use of cast enrichments of mouldings, and the desire for large spaces for the

painter's figures did away with the lesser division of the ceiling, and though the painter on the ceiling

imitated stucco work, the stucco worker himself was banished. Then came the troublesome time of

the Commonwealth, with the Spartan severity of the Puritans, and so both forms of decoration were

destroyed, and at the Restoration it was found necessary to import French and Italian plasterers

to execute what little was demanded. This, however, was not much, for Verrio and Laguere held

sway, and the stuccoer had only to prepare the ceilings and friezes for the painter. Indeed, had

more been needed, it could hardly have been obtained, for, as the stucco-worker's art had stagnated

during the troublous period, it, like all that stagnates, died. Again, most of those who had an}-

love for art found themselves on the wrong side of politics, and either perforce or \-oluntaril}- left

the kingdom. When the}- returned the}- brought foreign fashions and foreign fashioners with them.

Thus, when Lord Montague rebuilt Montague House, he employed Peter Puget, a French architect,

to design it, and Monnoyer, the French flower painter, came over to decorate it. Monnoyer not only

painted flowers, but modelled them in stucco, and hung festoons and wreaths everywhere, and

garlanded everything, endeavouring to make his stucco wreaths compete with the carved wooden

ones, such as Grinling Gibbons and his followers did so well. These floral decorations held their

sway for some time, often surcharged and pretentious, as in the ceiling at Astlcy Hall, where the

amount of labour expended is b}- no means commensurate with the effect. It partook too much of

126 /Vnsh'riiig — /Vail/ uitd Dccofaiivc.

the technique of the pastrycook and confectioner to liavc a lastinj^ hold, and was soon followed b)- a
better and purer character bnnitjht in by the Italian stuccatori, who again flocked into England.
Not only on the ceiling but on walls the stucco worker displayed his skill, and stucco once
more became a favourite mode of decoration The jjupils and followers of Sir Christopher Wren
adopted it ; and most of the houses and public buildings erected in the first half of the last
century are adorned with very excellent work, indeed so national had this custom become that in
1736 it was said plastered ceilings "are much used in England beyond all other countries; and
they have these conveniences with them — they make the rooms much more lightsome, are
excellent against raging fire, stop the passages of dirt, and lessen the noise overhead, and in
summer time the air of the room is somewhat cooler." The long foliated character of ornament,
erroneously called of the Chippendale style, followed this — a weak travesty of the French ornament
of the time of Louis XV., but frequently of beautiful workmanship. To this succeeded the revived
classic mode, in which the expiring efforts of the stucco worker exhausted themselves. Run
mouldings and cast ornaments henceforth pre\ailed. Thus expired the art and craft of the modeller
in stucco.

Paxi:i,LI:1) Ckh.IX(;s. — The term "panelled ceiling" is generally applied to any ceiling whose
surface is divided into spaces by beams, girders, or mouldings. Those enriched with mouldings are
also known in the trade as "figured" and "ribbed" ceilings. The term "panelled" is more correctly
applied to those having coffers or caissons, or where the ceilings are divided into spaces by beams or
girders. The spaces between beams are usually termed " baj-s," and they are often further panelled
with mouldings. " Figured ceiling " is a term sometimes applied to ceilings having small mouldings,
or where the design is composed of geometrical figures. " Ribbed ceiling " is a term general!}- applied
to those with rib mouldings on the intrados of arched or circular ceilings, also to flat ceilings having
circular mouldings. " Decorative flat ceilings" is a term ajiplicd to those with flat surface modelled
ornamentation, but without rib mouldings.

The ceilings of the Romans were generally of three kinds — the "hemispherical \ault," the
" barrel \ault," and the outcome of the intersections of the latter, viz., the "ground vault." It may
be said that mouldings of any form or number on a ceiling must divide the surface into panels of
some sha[x; or size, hence, for the sake of simplicity, the term "panelled" (unless the groined or
other special kinds) will hereafter be used.

Panelled ceilings may be formed on joists (wood or iron), brick, stone, or concrete work.
The first part is the brackets, if heavy mouldings are used ; and then the lath work, if on wood joists.
If on brick or stone, the joints should be cut out, and the surface hacked, to afford a key for the
plaster. Concrete surfaces are left rough, or fixing blocks inserted w hile the concrete is being laid.
The fixing blocks are to receive lath studding or fibrous plaster as required. Iron work is fitted
with wood clamps for a similar purpose. Those keyed surfaces are then first-coated, and floated
with strong coarse stuff. Screeds for the mouldings are next formed, and then the ceiling set out.
The mouldings are next run and mitred, and then the panels are .set. In some instances the whole
ceiling is .set first, and then the panel mouldings planted. The different processes are as follows: —

Rib Bracket-S and Lathinc; kor Fanklled CeiijN(;s.— Large ceiling mouldings, such
as coffers or caissons, mock beams, all require lathed brackets to form a foundation for the plaster
work. Spike and rope brackets are generally used for ordinar\--sized ceiling mouldings. The
mouldings may girth up to 12 inches or even 20 inches, but the girth need not be considered,
provided the moulding is not too deep. Any width of moulding can be amply secured by using two
or more rows of spikes. Rib mouldings 6 inches and 9 inches deep have been run on those kinds

Floating Panelled Ceilings. '-7

of brackets. Where the inouklings are wide and deep the floating should be cut down to the lath
work. This gives a further key to the bracket. The floating should be cut out before the spikes are
driven, so as to give more freedom for driving, and allow the lath work to be properly cleaned and
damped. Before the lath work on the ceiling is begun, small joists or strong quartering should be
fixed between the main joists where required, to receive the spikes. It is of the utmost importance
that the lath work for panelled ceiling should be sound and sufficiently strong to carry the rib
mouldings. For wood lathing, double lath gives the best results. Metal lathing is not only
strong, but has the advantage of being practically fireproof. It is false economy to use inferior
materials for this class of work. Rib and cornice brackets can also be formed with some kinds of
metal lathing. A spike and rope bracket is illustrated on page 144.

Floating Panelled Ceilings. — Panelled ceilings demand sound foundations. These are
formed by the first coat and the floating coats, the former being laid on well-seasoned and strong
laths, securely nailed, or on corrugated metal laths, or wire netting. The first and floating coats
should be composed of strong-haired and well-tempered coarse stuff. It is of the utmost importance
for panelled ceiling, and indeed for all kinds of plaster work where lime is used as a base for the
first coating, floating, and setting (more especially if the lime is of a rich or fat nature), that each
coat should be allowed to stand as long as possible before the next one is laid. This method of
laying the stuff in thin coats, with a considerable space of time between the layings, is conducive
to the ultimate hardness of the whole. Each coat is long exposed to the carbonic acid of the
atmosphere before being covered with the next. It is a common practice in some places to place
a fire of coke in a chauffer in the centre of the room, for the purpose of drying the plaster more
quickly, but the carbonic acid given off by the coke plays a very important part in the hardening,
as well as does the heat in drying. For the best class of work, or where the mouldings are heavy,
the coarse stuff should be gauged with li parts of strong coarse plaster. Great care must be taken
in the floating, so that the surface will be perfectly level and straight. Cornice screeds (the main
screeds) are first formed on all sides of the ceiling, and levelled b\- means of lath dots, which are
proved by the aid of a parallel ceiling rule. After the main screeds are made, narrow ones are
formed across the ceiling, and are ruled flush with the main screeds. The narrow screeds are laid
from 4 to 6 feet apart, or as required, and then the intermediate spaces are filled in and ruled flush
with the screeds. Gauged work should not be hand floated with water — water and working tends
to kill the plaster — but the work may be left moderately rough, to act as a key for the running
.screeds and setting stuff. If the ceiling has few mouldings, running screeds (of gauged putty, for
the running mould to bear on) are formed, where the mouldings are required. If the ceiling has
numerous mouldings, thus necessitating a double quantity of screeds — one for the nib and one for
the slipper of the running mould — it is best to form the whole ceiling smooth as well as level and
straight, thus forming one vast screed. This may be done by filling up the rough places in the
floating with soft-gauged coarse stuff, and then floating smooth with a traversing rule, working the
rule over the stuff all ways — lengthwise, crosswise, and diagonally — and testing with a long straight-
edge, and finally finishing with a hand float. The stuff should be gauged with size water, to give
time for properly ruling and floating before it is set. Another plan — a good one, and often
adopted for best work— is to leave the floating straight yet rough. This is best done by using the
floating rule flat on its face, and with a zig-zag motion cut off the excess stuff. If there are any
smooth parts on the surface left after this ruling, they should be roughened with a stiff coarse broom
before the stuff is set, or, if set, with a rough drag, and then brushing off an)- loose particles. While
the work is still green, form thin and narrow screeds to the main ones, i.e., screeds for the main

128 Plastering — Plant and Decorative.

cornice, and from these form a series of more narrow ones, about lo or 12 feet apart, across the
ceiling. When the screeds are set, fill in the intermediate spaces, and rule off flush. Before the
spaces are filled in the narrow screed should be tested crosswa)s with a long straight-edge, to see
that all are linable. Where practicable, the whole ceiling should be laid and ruled off from the
main screeds. The surface is made true and smooth with a straight-edge, working it in all directions —
crosswise, lengthwise, and diagonallj- — using a little soft-gauged stuff to make good any defects,
and finished with a hand float in a similar wa\-. The stuff for the above process is composed of
setting stuff, mixed with one-tenth part of well-beaten white hair, and then gauged with size water and
one-third part of fine plaster. All ruling and scouring should be completed before the stuff used
for each part of the process is set. When the mouldings are all run and mitred, the haired coat
must be roughened with a sharp drag, to key the surface and also fra)- the hair, to give a further
key. The surface is then dusted, lea\ing the fra\-ed hair loose and rough, thus ensuring a perfect
and permanent Vcy and cohesion for the final coat. Panelled ceilings may also be floated direct
from the lath work, and the surface finished, and also the mouldings formed with most of the white
cements or hydraulic plasters described in Chapters II. and III.

Settinc. Out P.vnelled Ceilings. — A knowledge of practical geometry is a useful acquisi-
tion for setting out panelled ceilings. Without this knowledge, plasterers will be disajjpointed as
to their speed, proficienc)*, and accuracy, and thej- will labour under great disadvantages from not
understanding the principles upon which all geometrical and all other forms of panelled ceilings arc
founded. The rule-of-thumb plasterer may think that he can set out the ceiling from the drawing,
but in most instances the drawing contains no scales, radius centres, and lengths. Vet even if
those details are given, a geometrical knowledge saves time and trouble, and gives the kcjnote for
setting out the full-sized working plan on the ceiling. Therefore it follows that while the rule-of-
thumb man is wasting time, temper, and energy, the proficient plasterer proceeds at once, and
sets out the ceiling correctly, expeditiously, and in a workmanlike manner.

Panelled ceilings are set out by various lines, which are formed on the ceilings, their numbers,
positions, and uses varying according to the design. For perspicuity and simplicity the lines are
divided into two classes, the first being the " skeleton lines," which gi\e the plan, showing the widths
forms, and positions of the mouldings and panels ; the second are the " working lines," from which
the various mouldings are formed. There are three kinds of skeleton lines, viz., " centre lines,"
" width lines," and " radial lines." The centre lines represent the centre, or half width, of the panel,
mouldings ; from these all measurements for others are taken ; therefore, being the main ones, the\-
are formed first. The width lines represent the width of the bed of the mouldings, and are u.sed
to show the intersections, and as a guide when cutting out the floating for keying purposes. Thej-
also are used as a fixing guide when planting mouldings. The radial are extra lines which are
required for certain designs. The}- are struck lengthwise, crosswise, and diagonal 1\- as desired, and
are used to give the radius centres for circular mouldings, and the angles of radiating mouldings,
also to prove the squareness of panels, and the intersections of moulding. There are three kinds of
working lines, viz., " screed lines," " rule lines," and " template lines." The first mentioned are formed
at the nib and slipper bearings of the running mould, and are used as guides for forming the running
screeds. These are not required where the ceiling is floated and formed as a whole screed surface,
and are only used for sunk panels and beams, or where the ceiling is left rough from the floating.
The rule lines give the position, and act as guides for fixing the running rules. The space between
one of the width lines and the rule line is equal to the width of the bearing part of the slippered
side of the running mould. The template lines are used as guides for fixing templates and

Setting Out Panelled Ceilings. '-9

trammels. A good guide for fixing templates is obtained by using centre marks and angle points,
which are got from or made on the centre and radial lines, similar marks and points being made
on the template. The corresponding marks are brought together when fixing. To avoid confusion,
the various lines should be made with different colours, thus — Black (charcoal or burnt wood) for
centre lines ; red (ochre or chalk) for width lines ; yellow (ochre) for radial lines ; and brown (umber)
or white (dry plaster) for the screed, rules, and template lines. White should not be used on a
white surface, but it may be used for screed lines where nicety is not necessary, or on a dark surface
where it can be easily discerned. All width and rule lines are taken from the centre ones. This is
best done by the aid of a " mould gauge." This gauge is cut from a piece of thin running rule, and
to the length of the combined widths of the moulding and the slipper part of the running mould.
One end is rebated equal in length to the slipper part, and a permanent mark is made on the centre
of the remaining part, which is equal in length to the width of the moulding. For instance, if the
moulding is 6 inches wide, and the slipper part 2 inches wide, the gauge would be 8 inches long.
When the centre mark on the gauge is laid fair with the centre line on the ceiling, a mark is made
on the ceiling at one end of the gauge and another at the inner square end of the sunk part, which
gives the widths, and another mark is made at the outer square end of the rebated part, which gives
the rule line. The square ends at the sunk parts allow a mark to be made with greater accuracy
and rapidity than if made at a mark on the front side of the gauge. Marks are made by the aid of
a knife and the mould gauge at both ends of the intended moulding, and the lines extended with a
chalk line in the usual manner. Most measurements and all repeated lengths and widths are best
done with a "size gauge." It is quicker and more accurate than a 2-feet rule. A "size gauge" is
simply a running rule, or a lath cut to the desired length.

Having mastered the names and uses of the lines and gauges, the setting out will be greatly
simplified. The main cornice is run first, and from the outer members the measurements for the
panel mouldings are taken. With a few exceptions all rib or panel mouldings spring from or
intersect with the main cornice, the upper members of which are the same in size and profile as the
panel mouldings. It is an important point to take the measurements from the centre of those
members, and not from the outside member, because the centres of those members are equal to the
centres of the panel mouldings. The neglect of this initial point has been the source of many
mistakes. The same remarks apply to ceilings panelled with beams or sunk panels. The positions
of the centre lines are marked on the ceiling at the outward member of the main cornice, and when
the marks have been made all round the room, they are extended longwise and crosswise by means
of a chalk line. If the designs contain diagonal or circular mouldings, the radial lines are formed in
the same way. The mould gauge is now applied at both ends of the various centre lines, keeping
the centre mark fair on the centre line, making marks for the width lines, and extending the lines
as before. No rule or other working lines should be made until the skeleton lines ha\e been proved
correct. After this the working lines are made and the running rules fixed, ready for running the
panel mouldings.

P.ANEL Mouldings. — Panel mouldings for ceilings are either "run" or "planted." Run
mouldings are those run in situ, and planted are those that arc " run down " {i.e., on a bench or
running board), then cut to the desired lengths and mitres, and then planted or fixed on the ceiling
where required. If there are no wood brackets, the floating coat should be cut down to the lath
work, so as to obtain the best possible key for the mouldings. For deep moulding, a spike and rope
bracket is used, as already described. The coarse stuff for roughing them out should be extra haired
and strong gauged. A muffle plate should be used on the running mould. A muffle plate is an extra

'30 Plastering — Plain and Decora five.

plate cut about J inch larger than the profile of mould plate, and is screwed on the mould plate to act
as a muffle to form a space for the finer material used for the finished surface. After the mouldings
are roughed out, the muffle plate is taken off, and the fine surface finished with the original or
mould plate. This is cheaper and quicker than making plaster muffles, es|iecially when there are
a large quantity of mouldings to be run. A muffle [liate is al.so best when running panel mouldings
in white cements. When many men are at work on a panelled ceiling, or even when there arc
numerous panels, it is best to have one or more sets of running moulds — one set cut to the
muffling line, and another set cut to the finished line. When this method is adopted, due care
must be exercised that all the inoulds are "horsed" alike in size and form, that they may fit the
running rules and screeds in unison. It is often necessary to plant short or circular parts where
there is little or no space for the running mould to work. Mouldings that are run in situ are
generally stronger than if planted.

Coffered ceilings, or those having deep |)anel mouldings, are usually bracketed and lathed.
Screeds are formed on the soffits or centre of the brackets, and on this parallel running rules are
fixed and a half of the moulding run from each side. In most instances an enrichment is used in
the centre of the moulding. In this case the screed should form the bed for the enrichment. A
level line and uniform depth of panel surfaces is obtained by levelling from the main screeds by the
aid of a parallel ceiling rule and wood gauges. For ordinary-sized moulding (on lathed brackets)
the panel surfaces should be levelled, and the moulding formed in the usual way. It is sometimes
advisable to cut the brackets at the intersections to admit of the mould being run in continuous or
long lengths.

Planted Panelled Ceilings. — Panelled ceilings having small mouldings and numerous
short or circular pieces, or small or intricate panels, are best done by a process technically termed
"planting" or "planted." The mouldings for this process may either be "run down" or cast. The
term "run down" is derived from the fact that the mouldings are run down on a bench or a running
board instead of being run up on the ceiling or /'// situ. Mouldings run /// situ are simjily termed
" run." When the mouldings are " run down," they are cut to the desired lengths and mitres, ready
for planting in position. For (planted work, the mouldings may also be cast in neat plaster, or in
any white cement, as required. Reeds were formerly used to strengthen both run and cast work.
Fibrous plaster casts are now also used for planted work. They are lighter and generally stronger
than solid mouldings, either cast or run down. The planting or fixing of ceiling or panel mouldings
requires great care, to ensure accuracy and permanency. All mouldings, whether run down or cast,
should be well undercut in the centre and cross-scratched on the bedding parts or outer edges, a
corresponding deep undercut being made on the ceiling, also cross-scratched on the width or bed of
the moulding. The fixing stuff should be composed of haired putty, gauged with an equal part of
fine plaster, and sufficient size water to retard the setting as required. A portion of the gauge is
stiffened with dry plaster, and used for filling in the deep undercuts in the cast and the ceiling.
The softer stuff is used for the cross-scratched parts on the cast and the ceiling. The stiffened
portion gives more strength, and allows the two thick parts to unite better and quicker than if filled
with soft stuff. The latter is spread over the scratched parts of the cast and the ceiling, being
pressed well into the crevices of the scratching, so as to e.xpel all air and afford a .solid joint. The
cast is then applied to the ceiling, and worked quickly but gently backwards and forwards into
position. The working to and fro unites the two surfaces, and e.xpels any globules of air or super-
fluous stuff. The intersections must be tried with a straight-edge or joint rule, to see if the piece
being fixed intersects with the adjoining piece. Heavy pieces may be further secured by screwing

Setting Panelled Ceilings. 13 '

to the joists. It will be understood that nails or thin rules are fixed on the line at one side of the
moulding, to act as a guide while the piece is being fixed. These kinds of panelled ceilings are
generall)- set before the mouldings are set out and planted. In this case no rule lines are required,
and no hair should be used in the soft portion of the fixing stuff, as the hair, unless a close joint is
made and the stuff cleaned off, is apt to disfigure the ceiling. The stuff that exudes should be
cleaned off before it is firm with a square-ended wooden tool, and the joint stopped with stuff similar
in colour to the cast. White hair is generallj- used in the putt}' for fixing fine work. Black hair is
generally coarser than white. The latter, being nearlj- of the same colour as the work, is not so
noticeable in the event of its being retained on the surface.

Setting Panelled Ceilings. — The setting of finishing coat of panelled ceilings requires
great care in the selection and manipulation of the materials. Various materials and methods of
using are employed, each having some individual merit for special purposes. The following materials
and methods are those generally used, viz., "putty finish," "hard finish," "fine finish," and "cement
finish " — the latter embracing different kinds of cements.

Lime Putty Finish. — This is the cheapest, therefore the most common finish. The putty is
gauged with plaster, putty alone being useless for this class of work. The proportions are 3 parts
of fine putty gauged with i part of fine plaster. As this stuff will not stand scouring, it is difficult
to obtain a true and uniform hard surface with it ; and unless it is quickly trowelled before set, the
surface is apt to peel in places, while excessive trowelling kills the plaster and renders the surface
soft. It is best laid in two coats — the first with a panel or a hand float to lay it fair, and the second
with a trowel to lay it smooth, each coat and the trowelling and polishing off to follow each other in
quick succession before they set. This work must be carefully brushed, to avoid a coarse surface.

Hard Finish. — This is used for the best class of work, and requires a special setting stuff,
termed "fine setting stuff". It is made with finer sand and lime putty than that used for ordinar)-
setting stuff The sand must be well washed through a fine sieve until free from mud and foreign
matter. The putty should be run through a fine hair sieve at least three months (the longer the
better) before being required for use. While the putt\- is maturing it should be kept well covered,
to protect it from dust and atmospheric changes. The proportions var\- (according to the qualit\- of
the limes used for the putty) from equal parts of putty and sand to i part of putty and 2 or even 3
parts of sand. The sand and putty should be intimately amalgamated by frequent working and
beating with a larrj' and a wood beater. A punching box is an excellent tool for this purpose. If
marble dust is procurable, add i part to 3 parts of the above stuff This should not be added until
the stuff is required for use. The marble dust renders the stuff tenacious and hard. It is gauged in
the proportion of i part of fine plaster to 3 parts of fine setting stuff, and laid with a skimming
float, ruled fair with a straight-edge, and then quickh- and lightly scoured with a panel float, using
a little soft-gauged stuff to fill up any small holes. Follow on at once with the trowelling, using
water sparingl}-, and finish by brushing first diagonally both ways, then crosswise, and finish length-
wise with a damp brush, and finally in a similar wa\- with a semi-dry brush. This class of work is
suitable where a hard surface is necessar_\-, also for small or intricate panels, where it would be
difficult to work a hand float. When finishing small panels with any kind of gauged stuft", the
worker requires a keen perception of the suction and setting powers of the materials, also dexterity
and lightness of touch, to preserve the mouldings from injur)- and obtain a fair and fine finished
hard surface.

Fine Finish. — This can also be used for the best class of work. The stuff for this is the same
as the above, with the addition of i extra part of sand — preferablj- silver sand. This stuff is used

'3- Plasto'iiig — Plain and Decorative

neat, i.e., without plaster, and a portion is mixed with one-tenth jiart of well-beaten white hair and
used for scratch coating. A scratch coat of this haired stuff is first laid with a skimming float.
Over this, and while green, a coat of unhaired fine setting stuff is laid. This surface is careful!}' ruled
with a straight-edge, being traversed lengthwise, crosswise, and diagonally both ways. The whole
surface is then scoured u|j without water, but simply using some soft stuff to fill up any small holes.
After a rest to admit of shrinkage, it is then scoured up three times with water, and then trowelled
continuously until the stuff becomes so smooth and hard that no impression is made on the surface
by the working of the trowel. The desired degree of hardness is also known by the clear metallic
and musical sound which is caused by the contact of two hard substances, the trowel and the stuff.
The sound becomes clearer and more musical as the hardness increases. The surface is then brushed
off" with a soft damp brush — not wet — first crosswise, then diagonally both ways, and finish length-
wise, and finally finish with a semi-dry brush in a similar manner, which gives a brilliant face. This
surface is true, hard, and the best for artists to paint on, as when dry the gloss goes off, leaving the
best of all surfaces for paint or gilt. The hardness may be further increa.sed by using lime water for
the scouring and trowelling, but using pure water for brushing off

Ce.MEXT F"INI.sii. — Panelled ceilings are sometimes finished with Parian or similar white
cements. In this case the foundation coat from the lath outwards is formed with a coarse quality
of the cement intended for the final coat. The working of white cements is described under their
respective names.

PORTL.VXD Ckmext CEILINGS. — I'anelled ceilings situated in a damp climate or exposed to
atmospheric moisture, such as porticos or open corridors, may be rendered damp-proof and durable
by using an admixture of Portland cement and coarse stuff for the foundation coats, and Portland
cement, used neat, or in combination with setting stuff, for the final coat. Metal lathing makes a
safe foundation for this class of work. Wood laths may also be used. In this case double laths,
nailed with i^-inch wrought-iron galvanised nails, are required. The laths should be the best red
Haltic. well seasoned, strong, and in narrow widths, and fi.xcd not less than ^ inch apart, so as to
afford a strong key for the first coating stuff, or, better still, to allow the stuff to be pressed through
between the laths until it envelops the whole of the lath work.

The coarse stuff" must be composed of thoroughly slaked lime, clean sharp sand, and strong
long hair. The whole must be well tempered, and seasoned by time. When required for use, it
should be retcmpered with a larry, and an extra quantity of hair added, to allow for the Portland
cement that is subsequently added to the stuff. P"ive parts of this stuff is gauged with 2 parts of
Portland cement for the first coat, and 3 parts of the coarse stuff" is gauged with i part of Portland
cement for the floating. The finishing coat is composed of 2 parts of setting stuff" gauged with
t part of Portland cement. This is laid, scoured, and trowelled in the same way as used for hard
finish. The panels can be more smoothly and expeditiously finished by using a "limed cement."
The addition of i part of well-slaked fine lime putty to 3 parts of Portland cement will render the
finishing stuff* " fat," plastic, and easy to work, and also increase the density of the work. The
mouldings are roughed out with the same kind of materials as used for the floating, and finished
with 2 parts of Portland cement and i part of fine lime putty. The cement must be sifted through
a very fine sieve, and gauged moderately stiff for the first coat, and run off" with soft-gauged stuff".
This process gets up the moulding with a surface as smooth as glass. These materials and methods
may be safely employed as an anti-damp plaster in exposed positions.

Fibrous Pl.\ster Panelled Ceilings.— Fibrous plaster is now largely used in the construc-
tion of panelled ceilings. The panels and mouldings are made in one piece, and cast in large sections.

Ceiling at IVinton House. 133

Large fibrous plaster slabs, decorated with low relief bands and foliage, principally in the
Flemish style, are now greatly in vogue. These slabs are screwed on to the joist, also on to concrete
ceilings. Fibrous panel mouldings are often screwed on to "solid work." I used fibrous plaster
panel mouldings and enrichments, which were fixed on solid plaster, wood, and on ceilings and
walls floated and set with Martin's cement, at the Palace Club, Westminster.

As to the relative merits of solid work and fibrous plaster, it maj' be pointed out that the
numerous examples of old panelled ceilings throughout the country which are still extant show
little or no traces of time ; but there are no ancient examples of fibrous plaster in the United
Kingdom which can be used for comparison. Fibrous plaster has the advantage of being light,
dry, and quickh- fixed, and it can be painted before or as soon as fixed ; but it may be safely said
that solid or lime plastering will remain the staple material and proce.ss for most permanent
purpo.ses. The following illustrations of working plans of panelled ceilings are given as a
practical supplement for working panelled ceilings.

Ceilinx, of King Charles' Room, Wintox House. — A perspective view and plan of
a part of the ceiling in King Charles' room, Winton House, near Edinburgh, built in 1620, is
shown in Plate XXX. It is a fine example of old hand-worked plaster, the rib and panels being
decorated with free and effective foliage, and the deep and well-balanced pendants lend a bold
effect. The frieze is of rare design, and is a fine example of the arcaded form. According to
tradition, this ceiling, and the drawing-room ceiling in the same house (illustrated on Plate XVI.),
were executed bj' Scotch plasterers who had acquired the art of ornamental plastering from the
French plasterers employed in the plastic decorations of several houses in Edinburgh for the
Scottish nobilit}- about that period, though Messrs Macgibbon and Ross consider them to be of
English origin, and Billing points out that the same details are used at Pinkie and Mora\-, and
argues that the same plasterers executed all three. The geometric formation is common to many
English ceilings of this date. There are no records existing or other definite evidence to
demonstrate the methods used b\- plasterers of the long past for the execution of the numerous
elaborate and beautiful plaster ceilings which still exist in many mansions. These examples prove
that they were grand geometricians, who also knew how to select and manipulate the necessarj-
materials, so as to obtain beautiful effects and enduring results.

A working plan of this ceiling is given, to show what would be the modern wa_\- of setting out
and working. Take the design to be contained in a square between the points A, A, A, and A, and the
panel B as the centre, it will be seen that this square is again subdivided into six smaller squares on
each side, making thirty-six squares in all, which form the design or pattern before being repeated.
The centre lines, marked i, 2, 3,4, 5, 6, and so on, as shown on the sides and ends, form the small
squares, and are repeated as often as required, according to the complete design and size of the
room. Besides being centre lines, they also give the centres of the B and c panels, the pendants
A, A, A, A, and the centres {d) from which the segments {e) are struck. The diagonal lines in the B
panels give the position and fixing points for the centre pattern. The diagonal lines may be
extended the whole width and length of the room, to prove the intersections of the B panels, and
the centres of the pendants A. Having set out and proved the skeleton lines, the working lines are
next formed, and then the running rules fixed. The running rules are first fixed to run all the
longitudinal mouldings in one line from one to the other end of the ceiling. Where practicable, all
those rules should be fixed at one time. This allows all those mouldings to be in hand at one time,
and the roughing out and finishing to be completed in each individual operation, thus saving
repeated mould muffling and changing of materials. It will be understood that the rules are not

'34 P/nsfcfiiie — P/niii and Decorative

fixed in short lengths, or in other words, a separate rule is not fixed for each separate length of
moulding, but that they are fixed in continuous lengths the full length of the ceiling, which gives
better results. The rules need not be in one piece the whole length of the ceiling, but may be made
up in lo or 12 feet lengths. Rules cannot be fixed in a continuous line on a ceiling having
moulding or pendant brackets, and in some instances, where they are diagonal or circular mouldings,
which cross the right-angle mouldings. In some cases it is advantageous to run those or other
mouldings first. Long lengths of moulding are generally run first, but no hard and fa.st rule can
be given. This, like many other plastic problems, is solved b}- the exigencies of the case and
the intricacy of the design. After the longitudinal mouldings are run, the rules arc taken down
and fixed for the mouldings that cross the ceiling, or at right apgles with the longitudinal
mouldings. I'or instance, in this ceiling the rules are fixed to run all the longitudinal sides of
the B panels, and the sides of the longitudinal C panels. After the mouldings are run, the
rules arc taken down and fixed for running all the other sides of the li panels and sides of
the C panels that run across the short way of the ceiling. The circular ribs (f) and the
short straight ribs (_/) arc run down, i.e., on a bench, then cut to the lengths, and mitred and
planted. The ribs (straight on jjlan and circular on section, as shown at the pendant), which spring
from the intersections of the (' ribs to A, arc run down on a cradle and planted. If there are no
wooden brackets on the ceiling to act as a bed bracket, or for the four ribs, it will be best to set
them in position on a cradle, piece-mould the whole, and cast and plant them in one piece. An
allowance must be made for an iron pi|)c or bolt (threaded at the ends) to pass through the work,
so as to secure the jjendant. The four leaves are cast and fixed, and finally the pendants, thus
completing the ceiling. A sketch of the pendant and a section of the panel moulding is given ;
also a scale of equal parts, to assist in any required enlargement. The scale is one-half of the
pattern taken between A and A. This is divided into ten parts, which, if required, can be again
divided into minutes. Having decided on the required size, take the half of the pattern and divide
it into ten equal parts, and measure all other parts from that scale.

Ceiling at Cakeatii House. — The annexed illustration (No. 20) shows the plan of a part of
a ceiling at Careath House, Aj-rshire. The house was built in 1847, from designs by Mr D. Bryce,
architect, Edinburgh. The plaster work was done by J. Ramage & Son, my father being the foreman.
One-half shows the centre and radial lines (the centre lines are made thick to better show the
design). The other half shows the centre and width lines. In this example the semicircular ribs
(whose centres are A) are run first, this being the reverse of the preceding ceiling. It is well known
that straight mouldings are far easier to mitre than circular mouldings, hence the reason for running
the semicircles first. They are run a little beyond the line of mitre, so as to allow for a mitre joint
to be cut out of the solid. The straight part can be run, and then mitred up to the circular mitre
joint. The short straight pieces are then run down, cut to the mitres, and planted.

The semicircle ribs are run from a " radius pin " (R p). This is a block of wood about 6 inches
square and \ inch thick, with a hardwood pin about 2 inches long and i inch diameter fixed through
the centre. The whole resembles a miniature hawk. This is fixed on the ceiling with screws, the
true centre being obtained by keeping the four angles in a line with the four right-angle centre lines,
as shown at R P. A hole to fit the pin is made in the radius rod, thus forming a centre and guide
for running the circular ribs. The use of a " radius pin " is far better than fixing a centre pin through
the lath work. The latter way is apt to break the lathing and floating, and the true centre is not so
easily obtained. After the circular ribs are run, the rules are fixed to run all the B, C, and D
mouldings from point to point. After these are run, the rules are fixed to run all the E and F

Plate XXX.

I H

'^u.,^.A'>^

■' r it.iM,

}m II l-r "in.,-"-!

1 w

rERSPECTivE View of Plaster Ceiling in King Charles' Room, Winton House, Midlothian, 1620.— With working Plan.

Constructing Panelled Ceilings.

135

mouldings. Then the short lengths, G, H, and i, are run down and planted. With a few exceptions,
all mouldings over i foot long are run in situ. The square pateras or shields (j) are cast and
planted. Their positions and centres are got by placing the angles of the cast in a line with the
right-angle lines. The pendants (p) are cast and planted. Their positions and centres are got by
temporarily fixing four nails in a circle line previously made on the ceiling, or by four quarter marks
cast with the pendants, and then placing the marks in a line with the centres of the intersecting
mouldings.

No. 20. — PoKTioN OK A Plaster Ceilinc, Cakeatii House, Ayrshire, 1847. With Working Plan.

Ceiling at Beeslack. — The annexed illustration (No. 21) shows the plan of a portion of a
ceiling in Sir John Cowan's house, erected in 1855, at Beeslack, near Edinburgh. The plaster work
was executed by J. Ramage & Son, m\' father being the foreman plasterer. This was the first job
on which I tried my "prentice han' " on the scaffold. As this ceiling is drawn from mcmoi_\-, I am
not certain if there were pendants, as shown, or if the ribs were simply mitred. The method of
setting out this ceiling is similar to the other geometrical designs which have been described. The
figures I, 2, 3, 4, and 5, at the side and end, indicate the working and centre lines of ribs, which at
their intersections form a scries of equal-sized squares, extending all over the ceiling from cornice to
cornice. The figure or design is contained between the lines i and 5. Diagonal lines drawn from
the angles of the square of the design give the centre lines for the diagonal ribs (D) and the

■36

Plasfcrine — Plain and Decorative.

pendants (r). To find the centres (c) for dcscribint; the scp;mental ribs (s), bisect the lines which
form the small squares, as shown. Segmental ribs, if small, are run ilown, cut to the desired sizes
and mitres, and planted. When cutting segmental ribs, such as in the |)rescnt exam|jle, care must
be exercised to cut them to the exact length and mitre, so as to avoid mitring the circular moulding

No. 21.— Portion of a Tlaster CEn.iM;, Bf.esi.ack, Midlothian, 1S55. With Working Lines.

or making an unsightly joint between the circular and straight mouldings. If the moulding is cut
to the exact size, and with clean square joints at the ends and sides (as shown at A), the pieces will
fit close and intersect true with the straight moulding, and will require only a little stopping to make
the intersection good. Having set out the working lines, fix the running rules to run all the long
mouldings that run longways, and then run the long mouldings that run crossways, as already

I'LATi: XXXI.

Plaster Ceiling, I'kinces Stkeef, Eimnhurgh, 1S50.

Modern Panelled Ceilings. i37

described. The cross short ribs (F.) and the diagonal ribs Td) are next planted. The segmental
ribs are planted last. The pendants are fixed after all the other parts of the ceiling are finished.
Pendants that are fixed before other parts of the ceiling are finished are liable to get displaced or
otherwise injured, especially if they are large or depend deep downwards. It is advisable to run as
much of the work as possible, as it is generally stronger and more expeditious than running it down,
and having the extra labour of planting each .separate part. Short ribs should only be run down
and planted where the mitres would be as long as the piece run. If short ribs are accurately cut to
size and mitre, little or no mitring will be required, and a little stopping will make the mitre good.

Ceiling at Edinburgh. — Plate XXXI. depicts a ceiling in a shop at Princes Street,
Edinburgh. This ceiling was designed by Mr D. Bryce, architect, and executed in 1850 by
J. Ramage & Son, and the modelling by W. Gillies, my father being the foreman plasterer. This
elegant ceiling is in the Elizabethan style, and is remarkable for its free and open panelling, and its
numerous pendant pateras, one being placed at every mitre. The fine and bold centrepiece depends
about 3 feet in depth. The main cornice is enriched with a fine running frieze ornament and other
enriched members, the whole being supported by pilasters with enriched capitals.

Ceiling in Throne Room, Holyrood Palace. — This ceiling, Plate XXXII., was designed
by Mr A. Mathison for the New Throne Room, which was reconstructed in 1854. The dimensions
of the room are 59 feet 4 inches long, 37 feet 7 inches wide, and 19 feet 10 inches high. The plaster
work was executed by J. Ramage & Son, and the ornament designed by W. Gillies and modelled by
the author, this being my first attempt for public work. The whole of the plastering and modelling
was carried out under the supervision of my father. It is said that the ceiling was designed under
the supervision of the late Prince Consort. This may account for the initials P. A. appearing in
one of the panels near the throne. All the lettering on the shields and ornaments read from the throne
end of the room — V.R. on the right, P. A. on the left. In the centre line, and hidden by the canopy
of the throne, comes first a large square, in which are the rose, thistle, and shamrock, with crown
above ; next, in small circle, the shamrock ; then a large circle, with St Andrew's Cross on shield,
encircled with " Nemo me impunc lacessit " ; followed by a smaller panel, with crown, and a centre,
the royal arms. The next large circle panel is the St George's Cross on a shield, with ribbon
encirclings, on which is " Honi soit qui mal y pense " ; then comes a smaller circle panel, with
shamrock ; and last, at end of each centre line, a large square which is a repetition of that over the
throne. Across the centre line, in the centre of the royal arms, the large circle panel has on the
shield a sceptre, crowned, from which branches the rose and thistle, with two crowns below, encircled
by " Tria juncta in uno." The opposite circle has the same motto, with three crowns on shield. The
design or pattern of the ceiling repeats itself four times, the royal arms being the centre. The
ceiling is painted and grained to imitate oak, and the idea has been so well executed as to deceive
many visitors as to the actual material employed. The enrichments are further decorated with
colour and gilding. The ceiling ribs are about 5 inches by 4^ inches. The main cornice is about
I foot 9 inches on the wall, and is enriched with a perforated cove ornament, consisting of the rose,
thistle, and shamrock, and foliage encircling a thick straight stem.*

Ceiling at Liverpool. — In some designs the panel surfaces between the ribs are enriched with
foliage, &c., leaving little or no plain surface, as shown in the annexed illustration (No. 22). This
shows the plan of a part of ceiling at 01\-mpia, Liverpool, executed in fibrous plaster by J. Davis.

* This photograph, and that from which Plate W'll. has been reproduced, were taken by \V. H. Davies,
Edinburgh, by special permission of the Lord Chamberlain, for publication in this book only, and are strictly
copyright.

138

Plastcriiig-

-Plaiii and Decorative.

-mM^ &^^3 -^T

N'o. 22.— Portion of a Fiiirous Plaster Ceiling, Liveri'ool. 1S90.

When constructed in the old or solid way, the mouldings are run first, leaving a sufficient depth for
the thickness of the ground on which the enrichments are cast. The enriched grounds are then
planted, and the joints made good. For fibrous work, the combined mouldings and enriched panels
are cast in large sections, and then screwed up in position and the joint stopped. When setting out
the ceiling for fibrous plaster, care should be exercised to form the joints of the moulding piece at
the parts least seen and most easily made good. The panel enrichments in this ceiling are modern,
but the geometrical design is old, and has been reproduced in several districts with and without
enriched panels.

Ceiling .\t Bradford.— The annexed plate (XXXIII.) shows the plan of the drawing-room
ceiling in a house at Bradford, erected in 1879. The plaster work was done bj- T. Cordingley &
Sons, and I am responsible for the modelling items. The design is in the Adam stj-le. The room
is 19 feet 6 inches by 14 feet 3 inches, as marked on the plate. The space in which these
dimensions are figured represents the width of the cornice. Bej-oiid this cornice at one end of the
room is shown the ceiling of the oriel window. One-half of the finished ceiling is shown, and the
other half illustrates the method of setting out, and shows the centres and figured lengths of
each radius for the oval, circle, and segmental panels. The centres for 15 feet 10 inch radius
for the side segments, and the 8 feet radius for the end segments, cannot be shown in the sketch.
These and the oval moulding are run from templates which have been previously set out on a floor.
The small circular mouldings are run with a radius rod mould. Great care is required in setting
out a ceiling of this kind to ensure the various mouldings intersecting truly and correctly, especially
at the four small circles, which intersect at the centre of widths of mouldings, and with the centre

Plate XXXII.

I'LASTEK Ceii.i.m;, Thkone Room, Hoi.yrood I'AI.Ai t, Elu.nhu Ki;il, 1S54.

Plate XXXIII.

Piaster Cfiiin, ai Kradford, in the "Adam Style," 1S-9.

Panelled Ceilings.

139

Plan

Section through A. B.

^0. 23. — Portion ok a Plaster Ceilixo, Uiblin, Early Nineteenth Century.

of widths of the four others. The ceiling over the semicircle bay window is filled in with
modelled fibrous plaster work.

Ceiling K'X Dublin. — The annexed illustration (No. 23) shows the plan and section of a
part of a ceiling in a house at Dublin, executed in the early part of the present century b\-

•40 Plastering — Plain and Decorafii'C.

J. Ho^an, a wcU-knouii Dublin plasterer. Hogan, assisted by his sons, did some fine plaster work
in Dublin and other parts of Ireland ; but owing to a lack of appreciation of good work, or through
plaster work being undertaken by builders or general contractors, the Hogans ha\c practically
been disj)laccd from the trade. The panel mouldings were run in situ, and the panel enrich-
ments were cast and planted, and the beads in the panel mouldings and the cove enrichment
were stamped and finished by hand. A section of the ceiling, through .\ H, showing the " centre
pendants," is given.

Cf.ILI.NC AM) W.^Ll. Dk(0K.\T10N.— The annexed plate .\.\.\IV.) shows a part of a
drawing-room ceiling and wall ilecoration in Hill Park House, I*'orfar. This fine modern mansion
was designed by Messrs Boucher & Cousland, architects, Glasgow. The prettily designed plaster
work and modelling was executed by J. Steel in 1870. The main feature in the ceiling is the
large o\al-shapcd moulding, with set-offs or breaks. The centre is ornamented with a very
elaborate centre flower (but not shown in this view). The outer panel surface is enriched with
diaper work in low relief. The main cornice is of a very elaborate nature, being fully enriched.
The walls are panelled in Keen's cement, and have enriched angles. Small circular panels containing
busts are placed between the main panels. The columns and pilaster, with their i^edestals, arc com-
posed of Keen's cement. The highly ornate mirror over the chimnej- is composed of carton-pierrc
and paste composition. .\ fine e.xamijlc of decorative plaster work is depicted on Plate XXXV.
This shows a portion of staircase landing over the entrance hall in Mr W. Macfarlane's residence,
Park Circus, Glasgow, designed by Messrs Boucher & Cousland, architects. The beautiful model-
ling and plaster work was executed by Mr J. Steel, Glasgow. This is a fine example of elliptical
arching in a semi-Gothic style. The medallion busts represent Mr W, V.. Gladstone and Sir W.
Armstrong. The elaborate moulded and fluted columns are composed of Keen's cement, and are
marbled and polished. This mansion was erected in 1880.

Gothic Ci:ilini;s. — Pure Gothic was first used in the thirteenth century. It is said that
the last epoch of true Gothic may be dated in the si.xteenth centur)-, or iinmediately before
the introduction of Italian architecture, which was made by John of Padua and other foreign
artists.

W'alpolc's eloquent writings in the middleof the last century won many admirers for the Gothic.
The celebrated villa at Strawberrj' llill is an example of Walpole's taste. It is said that Robert
Adam designed one of the ceilings. The building began in 1750, but was not completed until 1776.
Those who desire to fully appreciate the beauties of the Gothic style should read Mr Ruskin's
glowing essay on the " Nature of Gothic Architecture." There are also fine examples of Gothic
architecture in Scotland, Ireland, and Wales. It will neither be irrelevant nor uninteresting to
enumerate some examples that are proininent in plaster work. The Gothic plaster preceptors of
the past generation also demand a passing notice.

Ceilixc. .\T Toddincton.— Plate X.\X\T. dci)icls the plan of a part of the drawing-
room ceiling, Toddington, Gloucestershire, and Plate X.X.W'II. shows the same ceiling in
perspective. This very elaborate mansion was designed in the Tudor style b)' the proprietor.
Lord Sudely. Owing to its pronounced Tudoristic points, it has been termed by some critics
as the "Tudor of Tudors." The building was begun in 1819, and took over twenty years to
complete. There were no master-men, no sub-contracts or piecework on this gorgeous edifice
The whole work was done by the day, under the personal supervision of Lord Sudely, assisted by
Stephen Price, the clerk of works. The timber, stone, limestone, and oak for the lath work were
all found on the estate. The gypsum for the plaster was brought from Spurnal, Worcestershire,

Plate XXXV.

Decorative Plaster Work in Siairi a>e ..\ek Entrance IIai.i., I'akk Circus, Glasgow, iSSo.

Gothic Plaster PVork. '4i

and baked and ground on the site. James Robbins, of Cheltenham, was the foreman plasterer.
His son James had a rare experience on this job, as he not only served his full apprenticeship, but
also worked as a journeyman. The length of time taken for plaster work is accounted for by the
fact that although there was such a vast amount of work, very few men were emploj-ed. Plaster
models were made for the principal wood, stone, and iron work. These served to show the effect of
the design, and allow for alterations before being finally committed to the more expensive materials.
These plaster models, after the design was approved of, were used as models for the wood, iron, and
stone work. Plaster models are used for this purpose in most good works, Gothic or otherwise.
There are several elaborate plaster ceilings in this mansion, some in imitation of .stone, and .some in
conjunction with wood. The drawing-room is 40 feet long, 30 feet wide, and 20 feet high. The
pendentive ribs are internally supported by iron pipes. J. Robbins, the one-job apprentice, after
leaving Toddington, came to London, and was employed by Bartlett, a modeller and plasterer,
and eventually became a clerk of works. His brother Edwin is well known in London as a clever
but eccentric plasterer, who plods in plaster and patents.

:\IODERX Gothic Plasterers. — F. Bernasconi was a great master of Gothic plaster work.
He flourished in the latter part of the last and the early part of the present century, and he did
some fine work throughout Great Britain and Ireland, notably the grand staircase at Windsor
Castle, finished in 1801, and at Fonthill, designed by James V\'yatt ; also at Taymouth Castle, the
seat of the Earl of Breadalbane, designed by Elliott. The grand staircase in this last castle is said
to be the finest in Great Britain. It is 40 feet square, and 80 feet high. Among Bernasconi's
pupils may be mentioned Taylor, Herbert, and Parish, of London ; also J. Annan, of Edinburgh.
The latter was the grandfather of the present J. Annan, of Edinburgh and London, who is well
known in the trade in connection with his numerous works of plaster throughout the three
kingdoms. T. Jones, of Liverpool, has executed some fine Gothic plaster work in England.

Rule, of Durham, mastered the method of Gothic plaster work at Ravensworth Castle, the seat
of Lord Ravensworth, a building begun in 1808, from drawings by J. Xash. Ferguson, of Carlisle,
was initiated into the details of this branch of plastic work at Lowther Castle, Westmoreland, which
was designed by Sir R. Smithe, and the work commenced in 1808. It is said that the grand stair-
case is the largest in England. It is 60 feet square, and 90 feet high. Parsons, of London, was a
skilled plasterer, well versed in Gothic work. He was employed at Ashbridge, the seat of the Earl
of Bridgewater. This mansion was designed by J. Wyatt, and the building begun about 1814.
This is .said to be the most magnificent of modern Gothic mansions in England. R. Evans, of
Swansea, practised Gothic plaster work at Margam, in South Wales, a house designed in the Tudor
style by T. Hopper.

Pitts, Smith, and the elder Naimby did some of the modelling for the wood, stone, and plaster
work of the Houses of Parliament. H. Mabey was the shop foreman, and Blunt the scaffold
foreman, on Sir Charles Barry's masterpiece. Mabey was the progenitor of a clever race of London
modellers, and Blunfs descendants are also well known for their modelling and plastering abilities.
Tom Garland was a past master modeller not only in Gothic but in most other styles. Garland,
who was popularly known as the father of modellers, was often engaged b>' Thomas Cubitt and
W. Cubitt. He was also well known to Sir Charles Barry. Digby Wyatt, Gilbert Scott, and
other leading London architects.

Eaton Hall, Cheshire, the seat of the Duke of Westminster, was designed by W. Porden.
The building was commenced in 1803. This gorgeous mansion contains some highly decorated
plaster ceilings, and has four clustered columns, supporting a vaulted ceiling covered with a

1 42 Plasicyi)ig— Plain mid Decora five.

profusion of rib tracer)-. At one end of this apartment is a sub-library, of an octagonal form
(30 feet diameter), which opens to a second library (37 by 20 feet). The drawing and dining rooms
have elaborate ceilings ; the corridors have splendid groined ceilings. Some of the ceilings are
highl)- enriched between walnut beams, and others are decorated with rich rib tracer}- and bosses,
also with numerous shields, coats of arms, &c. A portion of this marvellous plaster work was
done under the supervision of H. Mabey, who, I believe, was a relative of C. H. Mabey, the well-
known modeller, of London. J. Annan, of Edinburgh, also did some of the Gothic plaster work,
J. Donald being the foreman. Messrs Smith & Taylor did another portion of the work. Mr F. J.
Curle\' did the modelling.

Sir Walter Scott's house at Abbotsford has some fine Gothic work. The great author, in
conjunction with Mr Atkin.son, was responsible for the design, and the plaster work was done by
J. Anderson, Edinburgh. There is a fine example of Gothic plaster work in Mr Graham's house
in Albany Street, Edinburgh. The plaster work was executed by J. Ramage, and the modelling
by R. Foster. There is an interesting example of Gothic work in a house near Edinburgh, said to
be designed by Kemp, who designed Scott's Monument. The plaster work was executed by
J. Ramage & Son, and the modelling by R. Foster. It was at this job that my father, fresh from
Caputh, Perthshire, made his first attempt in Gothic plaster work. On the death of Mr Ramage,
Foster and m\- father succeeded to the business, and did many plaster jobs in the Gothic and
other styles. \V. l^aird, of Edinburgh, was also an expert in Gothic modelling and plaster work.
There are some fine examples of Gothic work in Glasgow. Amongst them may be enumerated
St Matthew's Church, St Peters Church, and Anderston Church. These were built about the
middle of the present century, and the plaster work, as well as in several other Gothic jobs, was
done by Joseph Leach. W. Leckey was the foreman plasterer. Part of the modelling was done
by James Leckey, and the other part was done by James Steel, of Gla.sgow. On those churches
and other Gothic work J. G. Smythe served the greater part of his apprenticeship, and was often
employed six continuous weeks in mitring long intersections of clustered rib mouldings. Smythe
is now well known in London as a sound practical plasterer. J. Steel, the above-mentioned
modeller, who was born at Dundee, 1819, where he served his apprenticeship, had an intimate
acquaintance with the principles, spirit, and details of Gothic work. He eventually became a leading
master modeller and plasterer in Gla.sgow. Two examples of his work are gi\en herein. His son
James displayed great talents as a modeller, and after a brief sojourn in London he commenced
business in Glasgow, but was cut down in the flower of his youth and abilities. His business was
taken up and is still successfully carried on by his foreman, R. A. M'Gilvray, and R. Ferris, a pupil
of J. Steel, and a clever and artistic modeller. Caird & Darion were also noted in Glasgow for
their abilities in Gothic and classic plaster work. Hogan. of Dublin, was proficient in Gothic
plaster work. The elder Hogan worked with the brothers Clark. The fine Gothic plaster work
at Longnor Hall, Salop, was executed by W. M. VVellings, whose sons are now well known as
prominent plasterers in Shrewsbury and surrounding districts.

Groined Ceilings. — In order to render the method of .setting out and constructing groined
ceilings clearly, an example of one is here given. Plate XXX\T 1 1, shows the elevation and the plan
of one-half of a groined ceiling in Trinity College, Glenalmond, Perthshire. The founders of
this college were Mr \V. E. Gladstone and Dean Ramsay, of " Reminiscences of Scottish Character"
fame. The late Mr T. Henderson, Edinburgh, was the architect, the plaster work being done by
J. Ramage & Son, and the modelling by W. Gillies. A. Millar, of Blairgowrie, an uncle of mine,
was the foreman plasterer. The building of this college extended over a period of four jears, and

Plate XXXVIII.

Elevation.

Hale Plan.

Groined Ceiling, Trinity Coli.ec.e, Perthshire, 1S45.

Groined Ceilings. '43

was finished in 1847. The style is in the Perpendicular period of English Gothic. It will be seen
that the vaulting and rib mouldings spring from or are supported by a main or centre column,
while the other ends of the ribs are supported by corbels, as shown on the plan and elevation.

It is in Gothic work that a man's knowledge of drawing and practical geometrj' is of special
advantage to him ; but it must be admitted that there is in most cases a foundation prepared
for him either by the carpenter, bricklayer, or mason, who has had to set out the \arious curves
and lines for the constructional work. A knowledge of drawing and geometry will enable the
plasterer to set out his own lines required for templates and centres. It may be taken as a
general rule that the lines for vertical and diagonal mouldings are obtained by stretching a chalk
line from the springing of one side of a cove, arch, or barrel ceiling to the springing of the other
side, and hanging a plumb-line from the crown and other places of the circular work in hand.
The work is set out from a level datum line, which is struck on or just above the main cornice, or
at the springing of the vault.

The springing and intersections of the various mouldings according to the design are set out
and divided from the datum line. It will be understood that this datum line is carried all round
the room. A centre line on the intrados is required for setting out and showing the intersections,
centres, and positions of mouldings. The following is the truest and most speedy method of
running ribs on groined ceilings. First set out a datum line at the springing of the ribs. If there
is a cluster of ribs, fi.x an intersection board at the springings. The intersection board is made of
stout deal, and on it the plan of the ribs is set out, also the position of the foot of the template.
Templates are made with one or more pieces of timber, according to the length. The}' are from
li inches to 2], inches in thickness, and from 4 inches to 8 inches deep, according to the size of the rib.
They are planed smooth and true on the running sides and edge. Care must be taken when setting
out the template to allow a sufficient mould space between the running edge and the centre member
of the rib. This space is to allow a free passage for the centre part of the mould, also for the bearing
pins which are inserted in the slipper. The pins enable a mould to take anj- form or number of curves
on a template. The template is fi.xed with screws on the intersection board at the springing, and
secured at the crown with a jack. A cluster of ribs intersecting would in the ordinary waj- require
two screeds for each rib, and each rib being on a different angle, would necessitate a special curved
floating rule for each set of screeds. This may be entirely avoided, and the vertical and diagonal
screeds formed true and expeditiously, by running a narrow screed when running the ribs with
the running mould. The running mould is so formed as to have a sufficient bearing on the
template. After the ribs are all run, vertical or horizontal, pressed screeds are formed at various
points with rules of different lengths, and bear on the run screeds, after which the different bays
are floated and set as desired. Right and left diagonal ribs require right and left moulds. The
following illustrations elucidate the various parts of the jack and the template, which, when
combined, form a "jack template."

J.\CK Te.MPL.VTE. — The annexed illustration. No. 24, elucidates the construction and method
of working a jack template. The jack is an iron frame with screws, and is used for fi.xing and
holding the template or running rule in position when running Gothic ribs, mouldings on groined
ceilings, also for external and diagonal rib mouldings on large coves and vaulted ceiling.s. The
template has alread}- been described. Fig. 1 shows the section of jack and template (.\) in position.
G is the frame of the jack. This is formed with bar iron about 2 inches wide, and from \ inch to
\ inch thick. The top plate of the jack (TP), which has to carry the whole weight of the template
and running mould, should not be less than * inch thick, and be well welded or riveted to the

144

Plastering — Plain and Decorative.

ends of the frame (g;. The centre bolt (Ej is about \ inch thick, and made sufficiently long to give
a good hold in the ceiling. This bolt is fixed in the eye or centre of the rib's intersection. When
there is a series of ribs intersecting at one point, the centre bolt is kept in position till all the ribs
are run. The jack is turned round to the desired angle, to receive the template for running each
separate rib. When in position, it is further secured by two jj-inch screws, as shown at F, F. The
template {\) is regulated and held in position by the side screws (D, D) and the bottom screw (c).
These screws are about \ inch in diameter, each with a square head (in some cases a thumb plate)
for turning purposes, and on the point an iron grip plate, to ensure a firm hold on the template.
The position of the template at the springing is determined by means of the rib section (j), and the
position at the crown b>- the centre bolt (E), which is the eye or centre of the rib, and the
intersection of all the ribs. The template's position is further proved by holding up the running
mould at the springing and crown, to test the centres and depth of the rib. Fig. 2 is the side
elevation of jack and the template ; .\, G, and c being the same as in Fig. i. The other parts in this
sketch are as follows : —

^-tei..7-'^

WOOD

No. 24. — Jack Template and Spike and Rope Bracket.

"Spike and Rope Br.vcket." — A portion of this kind of bracket is shown at I! (Fig. 2).
One row of long spikes forms the depth, and two rows of short spikes form the width of the bracket.
One row in the centre is sufficient for small rib mouldings. The spikes are fixed from 6 to 12
inches apart, or according to the joints, cur%e of the rib, and the requisite strength for the bracket.
The spikes are made with a taper, or with notched sides, to prevent the ropes from slipping down,
and \\ ith a broad head to prevent them slipping off. The spikes, before using, must be galvanised,
or soaked in boiling linseed oil, to prevent rusting. After the spikes are fixed, strong tar bands or
ropes are twisted round the spikes from one to another, until the whole length of the row is com-
pleted, and so on in the same waj- with the other rows. This forms a strong and expeditious
bracket, adaptable for any cur\e, and giving a good key to the roughing-out material. .A further
key is obtained by cutting out the joints of the constructional work, or the floating from lath work,
as the case may be, and brushing and well wetting the bed of the moulding. This should be done
before the ropes are fixed, so as to give greater freedom for working. H is the running mould in
position, S is the slipper (this mould is described on p. 146), J is one-half elevation of the rib.

Running Gothic Rih Mouldings.

I4S

IXTERSECTIOX BOARU AND SLAB. — Illustration No. 25, Fig. i, shows the plan fone-half ) of an
intersection board, where the ribs spring from an isolated column. This intersection board is made
for four ribs. Intersection boards are used to set out the positions and sizes of the ribs and
templates, and to help to support the latter. The radius of the column and cap are indicated by
the dotted circle lines. The straight lines which radiate from the centre give the intersections and
centres of the rules (j,J,j). I is the intersection board, the a's are the feet of the templates, and are
held 'in position by the wood fillets (k). H is the plan of mould, S the slipper, and P the bearing
pin. A running mould for this class of work is made with a double stock. This sketch (h) only
shows one, so that the plate can be seen as fi.^ed before the second stock is screwed on. The

No. 25. — I'LAN OF Intersection Board and Jack Template.

plate is made in two pieces to allow the two sides to be placed together in a vice, and cut and filed
true to each other. Fig. 2 shows a plan of the template at the ceiling end. s and s are wood staj-s
to steady the template while the ribs are being run. They are placed at intervals on the off-side,
when the ribs are run in halves, and arc fi.ved with plaster gauged with lime putty water. The other
letters in this diagram correspond with the letters in Figs, i and 2 on illustration No. 24.

Ribs and Pin Moulds. — Illustration No. 26, Fig. i, shows the elevation of the run ribs and
intersection board, and sections of the template and jack, plans of which are shown at Fig. i,
illustration No. 25. Long templates are made in three or more pieces, as shown at A. The B's are
temporary wood brackets to support the intersection board. The space between the lowest
member of the rib and the upper or running edge of the template (a) is where the bearing pins of
the running moulds work. Fig. 2 shows the plan of an intersection board, where a cluster of ribs
spring from an engaged column or a corbel on a wall. In this example there are three full ribs

146

Plastering — Plain and Decorative.

and two half ribs. I is the intersection board, the A's are tem|jlatcs, and tlie j's the ribs. The
.same method is adopted for any number of ribs. Fifj. 3 is a view of a double-stocked running
mould. The method of makin<^ was parth' described when dealing with the mould shown in
Fig. I on illustration No. 25. This form of mould being narrow and weak at the lowest member,
is strengthened b)- the brace (u). The slipper (s) is made extra deep so as to give a counterpoise
to the half of the mould on the off-side of the tem[)late. The bearing side of slipper is hollowed

Ni>. 26. — Ku;. I. Ei.F.VAiioN of Kins. I'lr,. 2. l'i..\x of W.m.l Intf.rsf.ction Board. I'k;. 3. 1'is-Moui.d.

out, to give less friction and a more stead)- bearing. The two bearing pins (r, I') are made of hard-
wood ; each is about \ inch in diameter. No screeds are required in this method. A narrow
screed for floating from is formed by the two nibs of the mould. Gothic ribs, 2-fect girth, have
been run by this form of mmild and template.

Hali--Kih Pin-Mould. — A perspective view of a half-rib pin running
mould is shown in the annexed illustration, No. 27. This form of running
mould is used when the moulding is run in two parts, or one-half from
each side of the template. The circular " nib-slipper" (11) is generally used
when running half ribs, and also for running parts of ribs, s is a wood stay
fixed to the handle and the stock, to steady the deep part of the mould-
plate.

Mitring Rib Intersections. — Where three or more ribs intersect at
one point, a long mitre is unavoidable. In some rib intersections ])arts of
the mitre may extend several feet in length, and where the members are
undercut and intersect with each other considerable time and skill is
required to make the inter.section mitre true in .section and line. If there are no brackets, the centre
rib may be run nearly all the way ; but where there are brackets, the mould cannot be run farther
than where the side ribs intersect. In this case it is often advisable to cut the brackets at the inter-
sections, to allow the centre rib to be run as far as possible, and save unduly long mitres. When the
side or diagonal ribs are being formed, the mould cannot be run farther than where the intersection
begins. In this ca.se, the whole or a part of the bracket should be cut off where required, to allow
the running mould to be run down as far as possible. Another way to avoid long mitres is effected

No. 27.
Half-Rib I'i.\-Moui,d.

Panels for Classic Ceilings.

147

Octagons and Stjiiarfs.

Hexagons and Lozenges. Squares with Enriched Borders.

by cutting a template or running mould, having only the centre member, or as much of the side
members as can be freely run down to the foot of the ribs. After the centre members of the rib
are run, the side members are formed with templates, made to bear on the parts run. The various
members of the ribs are run as
far down as possible, and then
the whole is finished by hand
in the ordinary way. A good
method for long circular mitres
of this kind is to cut a plaster
template to fit the end section
of the rib, and then fix it on
the intersection board, or at the
foot of the rib, to act as guide
or bearing for the joint rule.
Two or more wood joint rules
are usually required for mitring
rib intersections. One .should
be cut to the ground section,
and one to the outer face
section of ribs. Another plan
to form long mitres is to make
a plaster cjdinder to the curve
of the ceiling, and on this run
the required length of ribs, then
cut them to the desired lengths */"
and shapes, and plant them in
position. Long and intricate
intersection mitres are some-
times cast. A model of the full
intersection is first made, and
then moulded, cast, and fixed
in position.

Old Gothic Material. — \

, Octagons, and }lexagons. Octagons, Hexagons, and Crosses. Hexagons and Triangles.

Gauged setting

stuff was often

used for the finishing coat of

Lozenges ivith Enriched
Borders

Squares and Eniureathed
Circles.

Squares and Stars, vith
Fleurons, S^c.

No. 28.— Panels for P.^wki.i.ed Ceu.inos, Classic Style.

Gothic mouldings. It attains
great hardness, and gives a
resemblance to the texture of
stone.

Classic Panelling.— To enable the young plasterer to comprehend the various forms of
panelling which are often used in the classic style of panelled ceilings, nine examples of
panels with their ornamentation, from designs by Sir W. Chambers, are shown in illustration
No. 28.

ClIAl'il'R \1.
RUNN/JVG DIMINISHED AND CIRCULAR MOULDINGS.

DiMixisHF.i) Columns— UixiiNisHKD Floating Ri'Les— Column Trammel— Constructinc; Diminisheh
Plain Columns— Uiminisheij Flvtes— Constructing Diminished Fluted Columns— Forming
Diminished Fluted Columns by the Rim and Collar Methods— Diminished Fluted Pilasters
— Panelled Coves— Pressed Screeds— Diminished Dome Mouldings— Cupola Mouldings-
Panelled Beams— Trammel for Elliptical Mouldings— Templates fur Elliptical Mouldings-
Plasterer's Oval— Coved Ceilings— Circular Mouldings on Circular Surfaces — Trammel
Centre— Forming Niches hv Running and Casting Moulds.

Diminished Columns. — The diminishing of columns is an intercstiiii; but somewhat difficult
operation. Great care must be exercised not to overdo the entasis or swelling. The swell may
commence very gradually from the base to the capital, or the third part of the column may be
of the same diameter, and then swell and diminish for the remainder of its height. Two methods
are here given to show how this ma)- be done. These are given more to illustrate the method of
setting out the diminished floating rules — so necessary to the plasterer — than to define the swell
or diminishing of a column, which, being within limits a matter of taste, pertains more correctl)' to
the architect.

The best instrument for forming a diminished column (plain or fluted; is a diminished floating
rule, with a cutting edge made to the contour of the proposed column. This rule is used to
determine the central position of the astragal and base mouldings (which act as bearings when
ruling off the floating stuff and the final coat), .so as to obtain a true and uniform diminish, and
al.so to form a fair surface. The aj^pended illustration (No. 29) elucidates the method of setting
out diminished columns which is al.so used for setting out the diminished rule for both columns.
The method for .setting out a diminished rule for a column that diminishes two-thirds of its height
is as follows: — The dimensions of the column having been fi.\ed, i.e., the height of the shaft and
its upper and lower diameters, draw a perpendicular line which may be taken as the centre line
of the column ; then set out the upper and lower diameters, as shown in Fig. \a. This figure
also shows one-half of the constructional brickwork, and the plaster, which is distinguished by
being dark shaded, with the floating rule in position. A floating rule for forming the curved and
dimini.shed surface requires an iron plate, similar to a mould plate, as shown, .so that it will cut
the stufi"o(if cleaner and truer, and last longer. The other half of the elevation shows the lines
and divisions for obtaining and setting out the entasis.

To diminish the column, first divide the height into three equal part.s, then at the lower third
(5) draw a .semicircle equal to the lower diameter of the column. Next divide the upper portion
of the column into four equal parts, as shown at 1,2, 3, and 4, then draw a line, parallel with the
axis or centre line of the column, from figure i at the top of the column, cutting the semicircle at
I, divide the remainder of the .semicircle into four equal parts, which gives the diminishing points.
From these points draw lines parallel to the axis of the column, and from the corresponding figures.

Column Tmmtnels for Diininished Columns.

149

as from 2 to 2, and so on. In these intersecting points fix pins or nails, and bend a flexible strip
of wood or metal round the nails, and draw the curved line. The whole line from top to bottom is
then transferred on to the board that is to be used for making the floating rule. This column will
have its greatest diameter for one-third of its height, and the upper portion its entasis. This
method is so far defective as to require the curve to be drawn by hand, a defect, however, obviated
by using a column trammel, which is used for a column that diminishes with a graceful curve from
the base to top of the shaft. This trammel is made as follows : —

COLUMN' Tr.\MMEL. — A column trammel is simple in construction, and when carefully u.sed
gives very satisfactory results, forming a graceful diminished curve from the lower diameter to the
upper diameter of the shaft. Before describing the method of setting out and constructing the

No. 29. — DiMixisHiNc; COLU.MNS — Column Trammkl .vnd Diminished Floatinc Kcle.

column trammel, the method of finding the point D on Fig. 2a is given on a separate sketch
(F'g- 5) to show the method more clearl)-.

Fig. 5 illustrates the method of obtaining the point D, on which the centre pin is fixed for the
trammel to slide on while working. This point also gives the length of the radius-rod. This
sketch IS reduced one-half in size to that of Fig. 2a, but the letters correspond to it. Having set
out the axis or centre line of the column (a B\ and the base line (A c) (extending the latter inde-
finitely), as described for Fig. \a, proceed as follows. From A as a centre, and from A to B as a
radius, describe an arc, as indicated b\- the dotted line ; then from the intersecting point at C as a
centre, and from C to the point at B as a radius (as indicated by the dotted line), describe an arc
until It cuts the base line at K. This done, add the distance from the point at A to the point at K to
the base line, outward from the point at C, which gives the desired point I).

'SO Plastering — Plain ami Decorative.

The trammel sin mid be set out on a wall or a clean floor. To set it out, first draw a line to
the exact hei;^ht of tlie proposed column, as A H an Fig. 2^/, then draw a line (indefinite!)' in
length) at right angles to .\ H, as shown from A to D. The line A li is the axis or centre line of the
column, and the line .V U is the base line. To construct the trammel, take two rules, each the
length of the column, and about 2 inches wide and i\ inches thick; fix one on each side of the axis
of the column, taking care to keep them equidistant and parallel to the axis, and forming a grooved
space about 2 inches wide, as shown at n, <r. the rules, and /;, the groove. These rules are made
thicker than the board intended for the floating rule, so as to allow the trammel pencil to run freely
when marking the diminished line on the board. This is shown b)' the section at l-'ig. i. I'his is as
when done in a temporar_\- waj- on a floor, but a better way is to fix the rules on a board (a flooring
board will be found suitable). This makes a permanent groove, and forms an easy gnumd for the
sliding block to work smooth!}'. It also allows a greater space for a thickt,-r board for the floating
rule.

Fig. 2 shows enlarged details of the groove rules (A, .\;, the groove (/>), the slirling block (li),
with the pin (l-i), the radius-rod (^v), with the pencil (g), and the board for the floating rule (c), with
the diminished line. Fig i shows a section of Fig. 2. The letters in all figures correspond with each
other. Fig. 2ii shows the whole column with the trammel and finished floating rule (c). Make the
radiu.s-rod about 2 inches wide, i inch thick, and in length a little longer than the distance from I)
to B, and the half diameter of base of the shaft. The sliding block (H) is about 4 inches long, antl
equal in depth and width to that of the sliding groove (//). It should be made smooth, and fit the
groove easilj", so that it will slide freel>- from end to end when working. In the exact centre of the
block fix a hardwood ])in or a round nail 11 . This must be fixed exactly over the axis of the
column, and so fitted that it will run immediately over it from end to end. Bijre a hole in the
radius-rod to fit this pin, then from the centre of the pin set off exactl)- half the diameter of the
base of the column on the radius-rod, which will give the point for the pencil hole (g). At this
point bore a hole large enough to receive a pencil, which must be tightly held in it. At the lower
end of the radius-rod cut a slot just wide enough to receive the centre pin at 1».

A plan of the radius-rod with the slot and centre pin is .shown at Fig. 3, and a section at Fig. 4.
The block beneath the radius-rod, in the section, is used to keep the rod level with the rules and
sliding block, as shown on Fig. i. To a.scertain the length to cut the slot, place the radius-rod along
the line A D, and the pencil at the outside of the .semi-diameter at the base of the column, and slide
it to its place; mark on the rod where the centre pin (d) comes; then place the pencil end of the rod
at the top diameter, and mark the rod again at the centre pin ; this will give the length of the pin.
Having made the trammel, provide a stout board to form the floating rule Tec . This board should be
planed on both sides and one edge. Place it near the rules a a, keeping the planed edge outwards,
and parallel with the axis or centre line of the column. This allows the planed edge of the floating
rule to be used as a straight-edge to plumb by when fixing the top and bottom rims or mouldings,
which are used as guides and bearings when floating the column. Place the sliding block in posi-
tion, and la)- the radius-rod over the centre pin and the pin of the sliding block, keeping the rod in
a line with I) .\, taking care that the pencil is in its true position ; then carefully move it upwards,
and pressing the pencil gently upon the board, which will give the line for cutting the diminishing
floating rule. The floating edge is strengthened b)- nailing a strijj of sheet iron on the board in a
similar wa)- to that in which a mould plate on a running mould is treated. This is of special u.se
when floating diminished fluted columns or pilasters, as the thin and sharp edge allows the flutes to
be more easil)- formed. The diminished line on the metal plate can also be formed with the trammel.

Constructing Plain and Diminished Fluted Columns. 151

A column trammel can also be used for setting out other diminished floatini^ rules for columns
less in size than the original one. The only alteration required for this purpose is to alter the point
D to suit the size of the proposed column, and the shortening of the radius-rod. It will be seen
that the floating rules for both columns are made long enough to bear on the base and necking
mouldings, but it is usual to make them shorter, so as to bear on cast or run rims or collars, which
are fi.xed at the top and ?jottom of the shaft.

Constructing Plain Di.minisheu Columns. — Plain diminished columns and pilasters are
formed with a diminished rule fashioned at both ends to work on the necking and base mouldings
(termed rims), or on collars. The method of making rims and collars, which are used as bearings,
is as described for diminished fluted columns.

To Set Out the Flutes of Diminisiied Column. — The annexed illustration (Xo. 30)
elucidates the method of setting out the flutes of a column. Fig. i shows the half plan of a column ;
A is the plan of the flutes at the base, and B the plan at the top of the shaft. P"ig. 2 shows the
elevation of the column, with the various parts marked. Fig. 3 shows the plan and centres for
setting out the flutings for the different orders with arrises or with fillets. A fluted column may be
divided into twenty, twenty-four, or twenty-six flutes, according to the style or order. There are
two different sorts of flutes used. One is worked to an arris, and sunk down in different depths, one
of which is described by the fourth part of the circle, one by the sixth, and others by the half circle,
as shown at C, D, E, Fig. 3.

The square or fillet of the second kind is equal to one-third part of the flute. It will be seen
in Fig. 2 that two lines are shown at the top of the flutes. The lower one shows how the flutes
finish when the fourth and sixth depths are taken, and the top line when the half-circle is taken
together with the fillets. Flutes that finish with an arris are usually emplo>'ed for columns in the
Doric order, and those that finish with fillets are used in the other orders. The fillets or lists at the
top and bottom of the shaft of a column, which serve to divide the shaft from the capital and base
mouldings, are commonl)- called the upper and lower fillets, and sometimes the horizontal fillets,
but in architecture they are known as " cinctures." The curved parts at the top and bottom of the
shaft which are usually curved into the upper and lower fillets by a concave curve or inverted
cavetto, are in architecture termed " apophyges."

Constructing Diminished Fluted Columns. — The formation of diminished fluted
columns by means of a running mould is an absorbing and vexed topic among plasterers, and
many ingenious plans have been advanced for the construction of hinged and spring running
moulds, and diminished running rules. I have kncjwn more than one self-improving plasterer who
has expended a \-ast deal of time and lime (not forgetting plaster) to prove b\- actual practice the
possibility of running a diminished fluted column, while others ha\-e been content to work them by
theory, forgetting that an ounce of practice is worth a ton of theor\-. Some men thought the\- had
accomplished a feat when they had run a single flute with a hinged mould, between two running
rules fixed to form diminution in width, forgetting or not knowing that flutes diminish in depth as
well as width.

The difference in depth of flutes, at the base and the top of the shaft, is shown at A, the base,
and P,, the top, in Fig. i, illustration No. 30. Running moulds have also been made with springs to
regulate the diminish in depth, but their action was uncertain, and they are also too expensive for
the purpose. Another form of running mould was made b}- fixing wire, catgut, or leather on one
end of one of the slippers, and on the upper edge of the stock, so that the slipper, when being
forced up the diminished space between the running rules, became more angular, or in other words,

Plastering — Plain and Decorative.

the slipper on which one end of the wire was attached was higher up the diminished space than
the other slipper, anti thus caused the stock to cant forward, or be drawn out of an upright, and
reduce the depth of the flute. The stock in this case is connected to the siip|jers, not b\- hinges,
but by a pivot inserted at each slipper to allow the stock to cant forward when pulled bj- the wire.
This form of mould also proved to be too erratic in its working to be of useful service. Running
moulds having the stock connected to a slipper at each side b)- means of two hinges (termed a
double-hinged mould) allow the mould to assume an angular or slanting form as it jjasses up the
diminished space, thus forming a diminution in the width of flute, but it does not form it with a

true arc all the waj-. On the contrar)', it assumes
an elliptical form which becomes more and more
pronounced as it reaches the top of the shaft.

The nearest approach to perfection in run-
ning diminished flutes is performed b)' means of
a running mould made with hinged slip])ers as
described, but having the mould ]jlate and stock
cut through the centre of the profile, the two parts
being then connected by a hinge. This form of
running mould (termed a " triple-hinged mould "j
allows the mould to coUajjse in the form of a V
on ])lan, and the slippers to run level or parallel
with each other, thus forming each half of the
flute alike, and at right angles froni the centre.
Still this has the defect of forming the flute with-
out the necessar\- decrease in depth. Various
forms of hinged moulds are described and illus-
trated in this chapter and in Chapter X.

A method for diminishing the depth of the
flutes is to make the running rules with a diminish
on face, or rather to make them with an increas-
ing thickness towards the top ends, so that the
mould when running up on the increasing thick-
ness will form a corresponding decreased depth
of flute. When running a fluted column b\- this
process, the running rules are fixed flush \\ ilh the
face line of the fillets. Only one flute can be run
at a time, but twelve maj' be in hand at the same
time. As there are generally t\vent\-four flutes
in a column, twelve rules would be required to keep a couple of plasterers going. When the
first set of flutes are run, the rules are taken ofi" and fixed to run the remaining flutes. When
all are run, the returned ends at top and bottom require to be made good. It will be seen
that the running rules for this method must be carefully made and fixed to ensure true
lines and forms. It will be understood that a bed or ground must first be formed as a
guide for .setting out and fixing the running rules on. This is done with the aid of a
dimini.shed floating rule. It will also be .self-evident that the floating rule would be more i^rofitably
employed for forming the entire .shaft with the flutes, thus dispensing with running rules and

CbCVATION

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P|.AN

No. 30. — DiMI.NlSlIED Flutf.d Colu.mn.s.

Patent Method for Forming Diminished Fluted Columns. '53

hinged moulds. This method of running the flutes is slow and tedious, but the worst part is that
the flutes are not true segments ; in fact, the whole of the methods mentioned are more or less a
rule of thumb, uncertain and inaccurate.

A knowledge of the rudiments of geometry will prove that the true form of a diminished and
swelled fluted column cannot be run with a mould, however ingeniously made. This may be
proved by cutting a plaster or cardboard disc to the former radius of a single flute, and describing a
line round it on a board. This would be the form the mould, when at right angles at the bottom of
the shaft, would give the flute. Then place the disc in an oblique position (the same as the hinged
mould would be at the top), and project the plan by means of a set square on to the board. It will
be seen that the mould would give the flute an elliptical form. It ma}- be further explained by
stating that when the mould is square at the base, or at right angles with the vertical running
rules, the form of the flute would be a true segment ; but when the mould is moved up the
diminished space between the rules, it assumes an oblique or slanting position. It gives the flute
an elliptical form, which increases and becomes more pronounced as it approaches the necking. It
ma)' be said that the pointed or elliptical defects can be filled in and worked fair with circular
hand floats, but this plan necessitates a series of hand floats to fit the ever-varying widths and depths
of the flutes.

It maj- seem unnecessar)- to describe the above methods, and then to point out their defects.
However, the methods and defects are given to prevent the rising plasterer falling into the
same errors, and to enable him to resist and rebut the arguments that are so often advanced
by some men, who persistently assert that their own ]3articular way (generally one of the methods
already mentioned) is the correct and onl\- wa\' of properh' ])erforming this difficult but interesting
operation.

It is W(jrth\- of note, to show the interest taken in this subject, that a patent was obtained
for a running mould and process for forming diminished fluted columns, in 1878, by J. Cleghorn, a
Glasgow plasterer, who obtained a provisional protection for " improvements in moulds or templates
for running stucco or cement tapered fluted columns." The following is a copy of the specification
iti extenso : —

"This invention relates to the running of stucco or cement in forming fluted or other columns,
pillars, or pilasters, and similar surfaces, in a more simple, economical, and expeditious manner than
heretofore ; and the nature and novelt}' of the invention as applied for running or making the body
part of a fluted tapered column of stucco or cement, consisting in constructing a short box-shaped
template, having two sides joined together b\' a back plate outside, with a handle upon it, for draw-
ing it up and down the column, and w ith an open space inside the back between the sides open
abo\-e and below, equal to any desired section or segment of the column at its base or widest ])art,
into which the column is equally divided b}' narrow longitudinal strips of wood, against which the
inner edge and end surfaces of the sides of the template slide close, so as to prevent the escape of
the semi-liquid or stucco. A thin elastic segmental mould plate is hinged or jointed at its ends to
the inner faces or edges of the template, formed in its inner scraping edge to corres]xind to the
segmental curve of the base of the column, with rounded projections corresponding to the flutes to
be formed on the column. This plate and its hinges are laid at an angle highest at the inner
scraping edge, and inclined downwards towards the back, leaving a space between it and the back
for the free passage or escape of the superfluous stucccj or cement scraped off the column during
the ascent of the mould along the column on its longitudinal shaping strips before mentioned.

"The one end or side of the mould is made to slide or contract iateralK- in slots or other

'54 Plastering — Plain and Decorative.

equivalent guides in the back of the mould frame as it ascends along the contracting or tapering
longitudinal laths, the thin plate bending or yielding down in a curvilinear form on its end hinges
before mentioned, so as to bulge inwards while bending downwards, and so contract the column in
a nearly true radial and segmental form from the bottom to the top of the column, the angle at
which the scraping mould plate is set on its hinges determining this contraction of the scraping
centre edge of its segment radia!l_\- in a ratio corresponding to the contraction of the length of the
segment and moving sides of the mould, which, for large moulds and columns, might be carried
and drawn up by handles secured to the tops of the ends of the moulds with ropes led up and over
pulle)'s at the top of the column, thence down to the hand of the operators, so that the mould may
be raised and lowered at pleasure to form tlvj whole segment of the column from t!ie bottom to the
top in nearly as siinple and efficient a manner as plain mouldings are at present run by the usual
simple edge scraping moulds, one segment being run after the other in succession until the column
is finished.

" For plain or other forms of columns the inner scraping edge of the mould plate is made to
correspond to the tapered surface of the column to be formed plain, segmental, or fluted as desired ;
and for flat, square, or polygonal columns, which do not require a segmental mould scraper, this
would be made straight, either plain or fluted, as desired, on its scraping edge, and set horizontally
on its hinges, instead of at an angle as describ-.'d for the segmental mould scraper for forming round
columns; and this mould scraping plate in any case is jireferred to be made of thin elastic steel
or tempered copper or brass, which would bend and contract the flutes or ridges on the surface of
the columns or pillars, equally and proportionally to the several parts of the column over w hich tlie
mould is traversed. Although the mould or template has been described as made with onl\-
one of its ends mo\-able laterall)', it is to be understood that both ends or sides maj- be fitted so
as to move in a similar manner to suit different kinds of work."

This patent method would be better understood if it had been illustrated. Xo provision for
diminishing the depth of the flutes is given in this method. The use (jf fle.xible metal for
diminishing purposes cannot be relied on ff)r accurate work.

Another method for forming diminished fluted columns is thus performed: — Make a single flute
in plaster, and use it as a mould for casting reverse flutes composed of fibrous plaster. After casting
as many reverse flutes as there are flutes in the proposed column, indurate them with litharge
oil or paraffin wax. Casts of the necking and base, each with about 3 inches of the fluted shaft,
are fixed on the brick core. The shaft is then laid with Portland cement for other desired cement)
and sand until within about one-third of the line of fillets, and while this stuff is still soft, take a
reverse flute (previously oiled), and press it into position, using the cement flutes at the necking and
ba.se as guides for fixing, and using a diminished floating rule to prove the outline. Repeat this
proce.ss until all the flutes in the column are filled with reverse flutes. The intervening spaces or
fillets are then filled in with gauged cement until flush with the outer surface of the reverse flutes,
and further regulated with the floating rule. When the stuff is set, the reverse flutes are extracted,
and any defects in the flutes made good. On the care in fixing the reverse flutes and filling in the
fillets depends the success of this method.

Diminished fluted columns are also made by casting two vertical halves, and then fixing them
on the brick core. The halves are fixed by means of cement dots, which are laid on the core at
inter\-als. Corresponding dots are laid on the interior of the casts. The casts are then pressed on
the core until the dots meet, and both halves are in proper position. The cast work is made .solid
with the core by pouring a thin and weak solution of cement and sand into an orifice at the necking.

Forming Diminislied Fluted Columns. '55

The cement and sand should be mixed in the proportion of one of the former to five of the latter.
This gauge has sufficient binding power and strength for this purpose, and is not Hable to expand
or contract in wet or dry weather. This process is useful for small work, and makes a good job
when cleanly cast and neatly fi.ved. The necking with the capital and the base may be fixed
before or after the shaft casts are fixed, according to circumstances. The shaft casts are best
formed in a reverse casting mould, as described in Chapter XIII.

Another method of casting a diminished fluted column is effected by making a reverse casting
mould. Fi.x it round the core, and pour the gauged material in at the top of the necking mould.
By using a reverse casting mould made with a plaster face and a wood backing, or a mould made
in fibrous plaster, the whole column with the core can be made in one piece. Hollow columns,
composed of Portland cement concrete, can be made to carry any weight supported by a stone
column, or one constructed with a brick core of equal diameter. Cast hollow columns are made by
temporarily fixing a wood or fibrous plaster core tapered to one end to allow it to be withdrawn
when the concrete is set. A rough wooden or a fibrous plaster hollow core is used when casting a
hollow column in situ. The core in this case is left in.

After many years' experience and observation on this subject, I am of opinion that the true
form of a diminished fluted column ("composed in Portland or similar cement, and constructed in
situ) is best obtained b\- hand, with the aid of cement rims or plaster collars and a diminished
floating rule. Most plasterers will admit that what can be and is done in stone or wood, can be
done equalh' well in cement or plaster. A plasterer has one ad\-antagc, inasmuch as he can add
as well as subtract when forming circular surfaces, whereas the mason can only subtract. The two
methods hereafter given for forming diminished fluted columns b\- hand arc simple, speedy, and
accurate. They are on one principle, and each may be used as circumstances require: one is
termed the " rim method," and the other the " collar method."

P'oRMiNG Diminished Fluted Column by the Ri.m Method. — First make models of
the half circumferences of the astragal or necking and base mouldings, each ha\ing about 4 inches
of the fluted shaft, as shown at Fig. i, the plan, and Fig. 2, the elevation, on illustration No. 30.
To make the models, cut a mould plate to fit each of the full-sized mouldings, and the required
size of the shaft, and " horse " them with radius-rods, and run a little over one-half of each circum-
ference in plaster, and then cut them to the e.xact half circumference. This done, set out the flutes,
then cut them out and form the returned ends. The method of setting out the flutes on the ends
of the models is shown on the plan at Fig. 1 . A is the plan at the base, and B the plan at the top
of the shaft. The returned ends of flutes are shown on the elevation. Fig. 2. Add the square
plinth to the base, as shown on the plan at Fig. i, which completes the models. Piece mould the
models in plaster, and then cast as many half astragal and bases as required. The materials used
for the casts must be the same kind as intended for the shaft. The brick or core of the column is
now cleaned and well wetted, and then the astragal and bases are fixed in position, using the dimi-
nished floating rule to prove if they are central, and the fillets linable with each other. Apply a
plumb rule on the back edge of the floating rule to test if the astragal and base are concentrical
and parallel with each other. When these half casts are fixed together on the shaft they are termed
" rims." The intermediate space on the shaft is then filled in and ruled oft" with the diminished
floating rule, using the rims as bearings and guides for forming the fillet line of shaft.

The method of forming a diminished fluted column by the " rim method " is further elucidated
by the annexed illustration. No. 31. This shows an elevation of the brick core of a shaft with the
astragal rim, A, and the base rim, B, fixed in position, u is the diminished floating rule in position

1^6

Plastcri)ig — Plain and Decorative.

for floatiniij the main or fillet line of the shaft. The method of usinj; a (iiminisheci flute rule for the
flutes is illustrated in the " collar method."

A second diminished floating rule is required to form the back surface of the flutes. This can be
quickl)' made by la\-ing the first rule flat on the floor, and from this, with comjjasses, describe the
back line of the flute on another board, which is afterwards cut to the desired line. This rule is
used as a long joint rule to form the flutes. The rule should be worked with uniform pressure,
the man at the top working in unison with the man at the bottom, both working the rule w ith a
circular cutting motion. The flutes are fined down hy the aid of a small float .semicircular in .section.
For extra large columns three floats should be used — No. i cut to the top section, Xo. 2 cut

to the middle section, and Xo. 3 cut to the bottom
section. The length of the floats may vary from 5 inches
to 7 inches, according to the height of the column. If
the columns are required with a smooth surface, the
flutes are worked as above, but the floats are covered
w ith fine felt, leather, or rubber, and the surface finished
smooth with short joint rules or with pieces of fle.xible
busks. The cast parts of the shaft, to the fillet members
of the astragal and the base, should be keyed with a
drag, so that the whole shaft, from arris to arris of the
astragal and base fillets, can be fined, thus giving a
uniform texture and colour, and avoiding a surface joint
of the cast work and the fined work.

A modification of this method is as follows:- — The
lower horizontal fillet of the shaft and the ba.se mould-
ings are cast separateh', the fillet part being used as
bearings for floating the shaft, as already described, and
the base is fixed after the shaft is fined. This plan
is useful for some purpo.ses, such as for extra large
columns, as it gives more freedom for working the
shafts, and the bases are not so liable to get injured
while working over them.

RuNMNt; Diminished Fi.utkd Column hv the
COLL.\K Method. — Run a plaster collar about li
inches wide to the diameter of the top horizontal fillet
of the shaft. The thickness must be regulated accord-
ing to the space between the brick core and the line of fillet. Cut this collar in halves and fix
them on the brick core, keeping the under side in a line and level with the top of the proposed
fillet of the shaft. Run another collar to fit the horizontal fillet at the base of the shaft, and
fi.K the upper side of this one level with the bcjttom edge of the fillet at base of the shaft.
This done, make two plaster models of the flutes, one for the top and one for the bottom of the
shaft, each about 3 inches wide, and in thickness according to the brick core, the diameter being
taken about i inch above the returned ends of the flutes at the to|) and bottom of the shaft.
These models are set out and made as described for the first method, but using plaster instead of
cement for the casts. The plaster casts are fixed in position, and then the brick core is laid and
ruled off, using the main diminished floating rule 'and the plain collars as bearings; for forming

No. 31. — FlOATEIi Kl.l'TED COLUM.VS-

RiM Metiioii.

DR is the main

Forming Diniitiished Fluted Columns by the Collar Method. i57

the main contour or line of the vertical fillets, including the horizontal or top and bottom fillets
of the shaft, and using the diminished flute floating rule (and the plaster models of the flutes as
bearings) for forming the flutes. This done, the fluted collars are cut out, the spaces filled in and
ruled off, and the returned ends of the flutes are formed, and then the whole shaft is fined while the
work is green. The fillet collars are thenVit out, and the astragal and base mouldings are then
fixed, thus completing the column. It will be seen that this method entirely dispenses with joints
between cast and floated work on the shaft, and allows it to be fined in one operation.

The method of running diminished fluted columns with the aid of collars is further elucidated
by the annexed illustration No. 32. AC is the top fillet collar, BC the bottom fillet collar, and FC
and FC are the top and bottom flute collars fixed on the brick core of the column.
diminished floating rule in position for forming the
main contour or fillet line of the column. This rule
is rebated at the top to allow for a bearing on the top
as well as on the edge of the collar. This rule al.so
forms the profile of the top and bottom horizontal
fillets, and the curved parts of the shafts below the top
fillet and above the bottom fillet. FR is the flute

floating rule in position when forming the flutes.

The ends of this rule as shown bear on the back

surface of a flute as indicated by the dotted lines. A

portion of the astragal moulding, A, with a part of the

shaft, is shown so as to indicate the position to fix the

fillet collar, AC ; a portion of the base moulding, B,

with a part of the shaft, is also given to show the

position of the bottom fillet collar, EC. It will be

seen that these collars form a fair bed for the astragal

and base mouldings, and when taken off they leave

true joints as indicated by the arrows at A and B.

A modification of the above methods for forming

the fillets and flutes is effected as follows : — Fill in the

spaces on the shaft between the collars in this method

— or the rims in the former method — and rule them

off with a main diminished floating rule as already

described ; and when the stufi" is firm but not set, the

positions and forms of the fillets and flutes are .set

out on the floated surface, then the flutes are cut out by hand by means of gouges and drags, and

afterwards fined as already described. This system is specially useful for small columns.

For extra high columns it will be found difficult to work a floating rule to form the whole height

of the column in one operation ; in fact, for some columns to be seen in London, which are 20 feet to

30 feet high, and even higher, it would be impossible to form them with one floating rule. It is

therefore necessary to divide the column into two or more sections, and cut the floating rules

accordingly. In this case two or more plaster collars about 3 inches wide, and made to the exact

circumference of the column at the point of division, are required. These collars are then

temporarily fi.xed in position to act as screeds, and after the whole surface of the column is filled in

and ruled off, the collars are cut out and the spaces filled in, and then the whole surface fined in one

No.

-FoR^^^■G Fluted Columns —
Collar Method.

15S

Phxstcriiig — Plciiii ami Decorative.

operation. Tliree or even more floats, as already described, are required for the fining of high
or massive columns.

Having now bricflj" reviewed tlie niore or less useful methods, and described some of the
most useful and practical methods, the conclusion to be drawn is, that diminished fluted columns
are best done b\- working them b_\' hand, with the aid of diminished floating rules and cast
or run bearings. The first or rim method will be found useful for many purjjoses ; but the
collar method, with the addition of intermediate collars for extra high columns, is the best for
general use.

DlMINI.SIIi:i> Fluted Pil.\sti;ks. — Pilasters arc said to be a Roman invention. They bear
an analog)- to columns in their parts, have the same names and standard of measurements, and are
diminished and fluted on the same j)rinciplcs. When pilasters are placed behind columns, and \ery
near them, they should not project above one-eighth of their diameter ; but if they are from 6 to lo feet
behind the column, as in large porticos and pcrist\-lcs, the\- should project at least one-sixth of their
diameter. When the}' are in a line with coluinns, their projection should be regulated by that of the
columns. When pilasters are used alone as principals in composition, tiicy should be made to
project one-fourth of their diameter to give regularitj" to the returned parts of the capitals. The
process for forming pilasters is the same as for columns.

Panelled Coves. — Large coves, segmental or elliptical
on section, having their surfaces panelled with mouldings which
spring from the back or above a wall or main cornice, and finish
at or intersect with a beam or other moulding at the top or crown
of the cove, require to be carefully set out and scrceded. The
floating is done from two horizontal screeds made at the top
and bottom of the co\e, and from these vertical screeds are
formed, and then the intermediate spaces or baj's are filled in
and ruled off with a floating rule bearing on the vertical screeds.
The horizontal screeds are easily made, but the vertical ones
require special care to ensure all being uniform in section.
These screeds are formed with a template cut to the desired
section, and about 2 inches thick. For large coves they are
made with three or more pieces of wood. The most correct
and expeditious way of forming circular screeds is hy the
'■ pressed screed " process.
Pressed screeds are simple and exjieditious in construction. They form accurate grounds for
floating purposes and for running mouldings on circular surfaces. The method of forming pressed
.screeds and floating coves is shown in the accompan)Mng illustration (No. 33). This shows the sec-
tion of a cove with the main or wall cornice and the crown moulding. F is a nib rule used when
running the main cornice. To float this cove for the running of vertical mouldings, first form the
to]3 and bottom horizontal screeds (a and B), then form the jjressed screed. This is effected by
temporarily fixing the template, G, or by one man holding it on the bottom screed, and another man
nolding it on the top screed, while a third spreads and presses the gauged coarse stuff until the
space between the first coating and edge of the template is filled up, then drawing the trowel
down each side of the template clears off any superfluous stuff. The template, which has been
previously oiled, is then removed, leaving a narrow but true and smooth screed ready for working
on. This method gives a truer screed, especially in cUijitical or long circular screeds, than floating

No. 33.— Section of Cove showing
Pressed Screed Process.

Floating Coves and Running Diminished Mouldings.

159

or working with a template, because if the template is not worked perfectly vertical, the cur\-e of
the screed is altered and not true.

The subjoined illustration (No. 34) elucidates the method of forming the screeds for floating
cove surfaces, also for floating segmental, elliptical, or any other form of interior and exterior angles
in coves. Fig. i shows a plan of the cove. The letters in this sketch correspond with those on the
same parts in the section on illustration Xo. 33. The first coating and the various bays, after the
screeds are made, are indicated by crossed diagonal lines at the d's. The top screed. A, should be
levelled from end to end and made parallel in depth with the crown moulding. Their levelness is
tested with the aid of a " levelling " rule. The bottom screed, B, should be made parallel with the
main cornice, so that the projection of the vertical mouldings will be uniform. The vertical screeds,
C, are next formed, making the first two near the internal angles, then two at the external angles
The intervening space is now set out, so that the screeds may be 8 or 10 feet apart. The screeds
may be formed farther apart according to requirements. If there are vertical mouldings to be run
in the cove, the screeds should be made at the sides of the proposed mouldings. It is always best to
have two or three screeds near the angles, so as to give a bearing for the floating rule, R. This shows
the position of the rule when floating the internal angle. The external angles on the other side are
formed in the same way. The
distance between the screeds
used for floating the angles can
be regulated according to the
depth or form of the angle.
It will be understood that the
floating rule must be suffici-
ently long to bear on two
vertical screeds, and reach to
the extreme point of the angle.
The floating rule, R, here
shown, is termed a grooved
floating rule. This is grooved on both sides, as shown b>' the section, s. This grooved floating
rule is described in Chapter XXI.

Fig. 2 shows the elevation of a levelling rule as used for levelling dots for ceiling, beam, or crown
screeds. This is similar to an ordinary parallel rule, but with the addition of a fillet, F, nailed flush
with the bottom edge to form a ledge to carr>- the spirit level, L. The levelling rule is applied on
the dots to test if they are level ; this is proved by inspecting the spirit-level ; if one dot is too full
it must be depressed until the levelling rule is level.

Diminished Mouldings. — Mouldings that diminish in depth or projection as well as in width
(termed " double diminished mouldings ") are not so common as those that diminish in width onI\-.
The diminish in width is simple, and is obtained by the aid of a "triple-slippered" running mould and
two running rules fixed to form a diminished space, as described hereafter. The formation of
a regular and pleasing diminish in depth greatly depends on the profile of the moulding. A mould-
ing having small members, especially at the sides, is more difficult to diminish than one having large
members, especially one with plain and deep fillets at the sides. Three methods are here given for
running double diminished mouldings on domes, cupolas, or vaulted ceilings, or on lower surfaces.
These methods give good results, especially if a little thought for the requirements of the case is
bestowed on the designing of the moulding.

No. 34. — Fig. i, Floating Coves. Fig. 2, Levelling Rule.

i6o

Plastering — Plahi mid Dcconifive.

DouiiLE Diminished Molldixgs — False Screed Minimi).— By this method the diminish
in depth is obtained bj- false screeds, and the diminish in width by the aid of a diminished rule,
which is fixed on the centre of the profile or bed of enrichment. This method is elucidated in the
following illustrations. The annexed illustration CSo. 35) shows the section of a vertical mouldint;
on the plaster or floated surface of the inside of a dome. C is the main cornice from which the
inner line of the dome springs. The D's are dots which are used to regulate the diminish of the
false screeds. The various thicknesses and positions of the dots are obtained by setting out the full
size of the section on a floor or worked out to a scale. If the section is elliptical, dots should be
placed at the points where the transition of
curves takes place. When the surface of the
dome has been floated, the diminishing dots, l),
are placed at each side of the intended moulding
and at their proper positions, beginning above the
main cornice, C, and going upwards in rotation
but having no dot at the top. The spaces between
the dots are ne.xt filled and ruled in, bearing on
the various dots with the curved rules or tem-
plates. When ruling the top bay of the screed.

Xo. 35. — Section Double Diminished Mol'i.iiinc.s-
False Screed Method.

Plan.

No. 36. — Elevation Dhuble Dimi-
nished Mouldings — False Screed
Method.

the top end of the rule bears on the original floating at the top or extreme point, this point being
the true thickness of the screed.

Illustration No. 36 shows the plan and elevation of the work. Fig. i shows it in progress,
and Fig. 2 when finished. The A's on plan and elevation (Fig. 1) are false screeds, the B's are
brackets, while cc indicates the diminished running rule. This rule is made as follows: — First
plane one face of a pine board about \ inch thick, and of sufficient length and width for the desired
purpose. On this make a centre line from end to end. From this centre line set off the width at

Rtinning Double Diminished Mouldings. i6i

one end, and the diminished width at the other end ; then extend the diminished width lines from
end to end, and then plane the running edges to the diminished lines. In order to allow the rule
to bend freely to the curved surface, make a series of saw-cuts crossways on the back or bed face.
The false screeds are made as already described. A centre screed for the running rule is made by
the aid of a template. This is made with two slippers, one on each side, similar to a running
mould, so as to run on the false screeds, the centre or cutting edge of the template being made to
the depth of the propo.sed screed. The face surface of the bracket is then laid with gauged stuff, and
finished off by working the template up and down. This done, fi.K the diminished rule, C, on the
centre of the screed. The running mould, K, on the plan is mad^ with the slippers, one to bear on
the centre screed and against the running rule, and the other to bear on the side false screed. The
slippers are made circular on their running edges, so as to fit the circular scre2ds. A short slipper
at the nib gives more freedom and ease when running the moulding, and the mould is not .so liable
to cut up the screeds. After the moulding is run on both sides, take the running rule off, then cut
the false screeds down to the floating, and make the sides of the fillet good, and then fi.x the
enrichment. Fig. 2 shows the plan and elevation of the finished moulding and enrichment. A, on
the plan, shows one side of the moulding before the false screed is cut off, and G shows the screed
cut off and the member made good to the floating. The amount of diminish from the bottom to
the top of the moulding is shown at the brac^cets B and B, and by the profiles of the cornice on
the plan and elevation. The bed and section of the enrichment is shown at F on plan. As this
enrichment is diminished (in width and projection), the whole length must be modelled.

Running Double Dlminlshed Mouldings, — Diminished Rule Method. — This is a
method which I have introduced, and is somewhat similar to the first method described. It is w'ell
adapted for running mouldings, having no enrichment on the centre of the section, the bed of which
may be used as a screed and bed for a running rule, as used for the first method. By this method
the whole moulding is run in one operation. The diminish in depth is obtained by the use of two
running rules diminished on the face, or in other words, diminished in thickness. The diminish in
the thickness of the rules is obtained by setting out the full size, as described for the false screeds in
the first method. A series of saw-cuts must be made on the backs of the rules to allow them to
bend to the circular surface of the dome. These rules act in a similar way to the fal.se screed used
in the first method, with the addition that they form the fillets of the outside members, thus avoid-
ing cutting the screeds down and making good the fillets. They are also used for obtaining the
diminish in width. This is effected by first making a central line on the bed surface of the pro-
posed moulding; then from this line, at each side, set out the half width of the moulding, including
the bearing parts of the running mould. This is done at the widest or bottom end of the moulding,
and at the narrowest or top end. Then from these width marks, lines are extended from end to
end. On these lines, nails are inserted from 2 to 3 feet apart, which act as guides for fixing the run-
ning rules. The inner sides of the rules are placed against the outer sides of the nails and fixed, and
then the guide nails are extracted, thus forming the diminished space and bearings. A triple-hinged
mould with a slipper at each side is used, so that it will close up while being run up the diminished
space. The stock is rebated, .so that it will run on the tops and inner sides of the rules. The mould
plate must be cut to fit the section at the greatest width of the moulding, but care must be taken
that the depth at the outer members is the same as proposed for the top. The ends of the inner
slippers and the adjoining parts of the stock are cut so as to leave an open space, to allow both
parts to work freely when the mould assumes a raking position, as shown on illustration No. 37.

The extra depth of the square of the outside members is formed by the running rules. It

i6:

/Mastering — Plain and Decorative.

nia\- here be reniarked that the thickness of tlie rules at the top should be made about i inch
thicker than the depth of the square part of the outside members. For cxam|)le, if the depth of
the fillets or square part of the outside members is i inch, the rules should be \\ inches thick at the
top. This allows for the requisite bearing for the running mould. The ends of the stock that bear
on the inside of the rules must be rounded off to allow the mould to run freely when it closes ui>
while being run up between the diminished space.

The various parts of the running mould are shown in the annexed illustration (No. },']). Fig. i
shows the mould in position at the bottom or widest part of the mouliling ; R, R, are sections of the
running rules; s, .s, the slippers; and II, II, the hinges which connect the two halves of the stock to the

sli]jpers. The hinge which connects the mould in
the centre is fixed on the other side of the stock.
Its poiition is indicated by dotted lines. Fig. 2
shows the form of the mould when at the to]j of
the moulding. The letters correspond with those
on I'ig. I. The thin seams at the centre and
sides of the moulding which are caused b)- the
joint of the mould in the centre and by the joint
of the mould and the rules are cleaned off b)-
hand. This method, like the first, has the defect
that the actual diminish or the whole depth of
diminish lies in the fillets of the outside members
of the moulding. The difference between the di-
minished members and the regular members will
be most noticeable on the adjoining members,
the vertical fillets of the cavettos. If this defect
should prove offensive to the eye, it may to some
extent be remedied b_\- working these members
down by hand, with the aid of planes, gouges,
drags, and joint rules, after the moulding is run,
so as to reduce the depth of the fillets, and throw
the difference into the cavettos. A line should
be set out to the desired diminish on the fillets
to act as guides when working the cavettos down.
RrxNiNc. Double Di.minisiikd Mould-
ings — Top Rule Method. — Running double
diminished mouldings by the aid of a "top rule"
is another method that I have introduced for this
purpo.se. The diminish in width is obtained by fixing two slii)]:)er running rules to the desired
diminish and a triple-hinged mould as previouslj- described, and as shown at F"igs. i and 2 on the
annexed illustration, No. 3S. F'ig. 1 .shows the running mould, M, and the slipper rules, R, R, at the
full-sized or springing end of the moulding, and Fig. 2 shows the running mould and rules at the
diminished end. The diminishing depth is obtained by the aid of a "top rule," which is fixed on
two blocks, one at each end of the moulding, as shown at Fig. 3. This shows the elevation of one
side of the running moulds at the springing and diminished ends of the moulding, also the running
rules. B is the section of the fixing block at the springing end of the moulding, and D is the fixing

No. 37. — Ei.Ev.\Tio.-<s AND Section of Running Mould
AND Rules for Doublf, Diminisiikd Mouldinc.s —
DiMiNisHKii Rl'lk Method.

Running Double Diminished Mouldings — Top Rule Method. 163

block at the diminished end, upon which the top rule, T, is fixed. This rule is fixed on the slant, to
suit the desired diminish. It must be made sufficiently wide to allow a bearing for a part of each
half of the stock, M M, of the running mould, and also fixed over the joints of the mould, as shown
at T, Figs. I, 2, and 3. The top rule being fixed on the slant, causes the running mould to gradually
cant over when it is drawn from its upright position at the springing end of the moulding to the
diminished end, as shown at Fig. 3, thus forming the diminish in the depth of the moulding. M a
shows the end section of the stock in an upright position when at the springing end, and M is the
.section of the stock in a slanting position when at the diminished end of the moulding. The dotted
lines in both indicate the parts of the stocks inside the slippers, and the angular dotted line at H, H,
indicates the splayed or cut side of the hinge, .s s is the outer elevation of one slipper when at each
end of the moulding, and R is the slipper running rule.
It will be seen that the running mould at Fig. i is
.somewhat similar to the triple-hinged running moulds
previously described. But there are two important
exceptions, namely, the hinges at the centre and the
two sides of the mould.

The side hinges for this mould must be cut on
one side and the angles rounded off, leaving only one
screw-hole, so as to cause less friction, and allow this
part of the hinge to turn on a screw when fixed on the
slipper. The use of this will be seen hereafter. An
elevation of a hinge, before and after it is cut, is shown
at Fig. 4. The lower hole on the cut half of the hinge
is used, because the nearer the "turning points" or
pivots are to the running ground or screed, as the case
may be, the less will the bearing edges of the running
mould rise when the mould cants over. For instance,
if the " turning points " were made at the centre of the
depth of the mould, the bearing edge of the mould
would rise from the ground in proportion to the cant
of the stock. This would increase the depth of the
lower members (those below the pivots or turning

points), instead of diminishing them. This hole must

No. jS.^Ei.EVATioNs, Plan, and Sections of
RrNNiNc, Mould and Rules for Di.mi.mshed
Mouldings— Tor Rule Miniion.

be enlarged so as to admit of a short thick screw to
give the necessary strength. It will be understood
that this part of the hinge works on the plain part at
the head of the screw.

Having cut the right and left hinges, they are screwed on to the stock and the slippers of the
running mould, keeping the half of the hinge with the three screw-holes on the stock, and the cut
part with one screw-hole on the slippers, as shown at H, H, Fig. i. It will also be noticed that these
hinges are fixed at the lower edge of the mould. This is done so as to allow the stock of the mould
to cant from its base for the reason already mentioned. When screwing the cut side of the plate to
the slipper, allow just sufficient pla\- for the hinge to turn smoothly but firmly on the screw. The
centre hinge connecting the halves of the stock, M M, is formed with two pieces of metal plate. The
inner ends are rounded off to allow them to turn, and a circular orifice one-third the width of the

i64 Plastering — Plain ami Decorative.

plate is drilled at the circular ends, and then three ur more screw-holes for fixing purposes are drilled
on the other ends. The two plates are fastened together with a flat metal ring or with stout copper
wire. The thickness of this ring is regulated according to the size of the orifice, but allowing just
sufficient play for the plates to turn both ways when the mould assumes a slanting and an angular
position, as shown at Fig. 2. An enlarged \iew of the centre hinge is shown at Fig. 5. The centre
hinge is .screwed on the inner side or profile of the stock, as shown at c. Fig. i. An enlarged view
of part of the stock at the joint, when inverted for fixing the centre hinge, is shown at Fig. 6. The
top and bottom edges and the ends of the stock must be rounded off, to allow it to cant over more
easily. The diminish of this moulding, both in depth and width, as shown in the illustration, is a
little more than may generally occur in practice, but this is given to show the various parts more
clearly, also what to avoid in the amount of diminish when using this method.

The diminishing depth here shown is about two-fifths, and the diminishing width about one-
third. The diminishing depth, by this method, should not be overdone, because the running mould
assumes an angular position both on plan and section, therefore it forms the vertical parts of the
members in a slanting line and the horizontal parts out of a level. These defects become more
pronounced at the diminished end of the moulding, as shown at Fig. 2. The to]j member can easily
be made level and fair by hand, but it would entail too much labour to rectify the defects of the
other members, therefore this method should only be used for small mouldings or where the diminish
in depth is of a slight nature. The seam at the to]3 member, caused by the joint of the mould, is
cleaned off and made good bj- hand.

Fine examples of diminished mouldings are to be seen in the new dome of the National
Gallery. The mouldings are diminished in width only, but the centre enrichment is diminished in
width and depth. This enrichment was modelled in sections to make u]5 the whole length of the
moulding. The various sections were then mtjuldcd, cast, and fixed scparatcl)-. There are other
fine e.xamples of ornamental plaster work in the various new galleries, mostly different designs,
which were built at the same time (about twenty-five years ago) as the above-mentioned dome.
The late Sir Charles Barry was the architect. The plaster work was done by Messrs H. & H.
White, the modelling by J. Xaimby and the author. R. Maskell was the shop foreman, T. White and
W. Tipping were the scaffold plasterers, and S. Otley was the general foreman plasterer. Parian
cement was used for the principal portion of the work, and superfine Keen's cement was used
for the Corinthian capitals on the marble columns.

Cupola Panels and Mouldings. — In order to facilitate the setting out and formation of
cupola panels and mouldings, the method of drawing them is given. This will be found very
useful in the general setting out and construction of cupolas, whether in "solid" or in "fibrous
plaster." Various parts of cupolas and soffits of arches (from designs by J. Gibbs, architect, a pupil of
Wren, and a great patron of the plasterer's art), with the method of drawing same, are illustrated on
Plate XXXIX. To draw an octagonal cupola, as shown by the plan at Fig. i, take A 13 (the width of
one side of the octagon) as the base line. From the centre of this erect the perpendicular line D C,
then draw the lines c A and C B; this will give the triangle ABC, forming the plan of an eighth part
of the cupola. The profile (P"ig. 2) is made by the quadrant of circle (A B C) directly over the plan.
Divide half the base line, A B on plan, into .seven parts, as here figured, and six of them will make
two panels; the seventh will remain for the border. The same divisions must be marked on the
profile over the line A B, as follows : — Take for the border at the bottom four parts, as shown in the
plan; place them on the profile from the base line to No. i, and draw a line parallel to the base
line of the plan ; measure the length of the two central lines marked 2 2, and place it in the profile

Plate XXXIX.

-^''■^m4^

^ /^i

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i

■I

*i2s

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Setting Out and Plastering Cupolas. 165

for the second panel. From thence draw another parallel line, and measure the length of the two
central lines at 3 3 in the plan to find the square height of the third jianel, and so on to Xo. 8, as
shown in the plan and profile.

The elevation or upright side of this octagonal cupola (F"ig. 3) is made by the following
geometrical rule. First draw the base line (A B) on plan even with the base line (A B) of the
profile; on this erect the perpendicular line (D C) for the centre of the side; then draw all the parallel
lines as shown by G, G, &c. Take half the length of each line, figured in the plan, and mark it on
each side of the middle line of Fig. 3 until the length of every panel is fixed. From these lines
and points the forms or outlines of the panels are taken. The inner divisions are brought o%'er to
the number of panels contained therein in the same manner as they appear in Fig. 3. The same
rule is used for setting the side shown at Fig. 4.

With regard to the soffits of arches, if they are divided into panels, they must be of any un-
even number, as shown at K and L, by having a panel in the centre. The border must not be more
than one-sixth nor less than one-seventh part of the whole breadth. The quadrant or profile, E F
(Fig. 2), on which the panels of this semicircular soffit are divided, will be sufficient to explain
them. A circular soffit of lesser breadth is shown at M, and one of greater breadth is shown at N.
Sections of each soffit are shown at the top of the elevations.

The method of constructing the plaster work of cupolas depends to .some extent on the design
and size of the panels and mouldings. For example, if the diagonal panels shown in Fig. 3 were
sufficiently large to admit of a running mould to run a piece of moulding (on each side of the
panels) not less in length than the mitres at each end, the best method would be to run the four
sides of all the panels ; but if the panels were too small to allow a running mould to run the
requisite amount of moulding, it would be necessary to run a part, and cast, or run down, and plant
the other parts. In some designs it would be necessary to plant all the mouldings. In some cases
the panel mouldings, from the base up to a third or fourth of the height of the cupola, can be
convenientl)' run ; but the panels above this which become smaller, and are too small to admit of
their being run with economy, should be planted. Another method is to run all the diagonal
mouldings that spring from left to right, as from A to a, in one length from border to border, and
then run the intermediate parts of the mouldings springing from right to left.

The intermediate parts may also be run down, or cast, and then planted. By this method the
intermediate parts only require mitring, and if they are planted the intersections only require to
be stopped. If these parts are run, the brackets from right to left must be cut down at the inter-
sections to allow the running mould to pass when running the mouldings from left to right in one
length. Whichever method is employed, the surface must be floated true to the various curves to
form a ground for the mouldings, whether run or planted. The surface should also be floated
sufficiently smooth to act as screeds without using gauged putty screeds for each moulding. This
is done as described for panelled ceilings. The groundwork of the floating is effected by first
forming a screed on the base border (A B), and one on the top border (at C), and then from these
screeds as bearings, form two screeds on the side or vertical borders, thus completing the main
screeds, and from which the panel surface is floated. Owing to the brackets and the form of the
panels, it is a somewhat difficult operation to float all the panel surfaces with a uniform depth and
curve. It will be seen that a floating rule (cut or so constructed to clear the brackets), whether
worked vertically or horizontally, cannot travel into the angles, and float the whole surface. This
difficulty is overcome by making dots in each angle, or making narrow screeds from angle to angle of
each panel. The horizontal dots or screeds as the case may be, are ruled off with a gauge rule,

1 66 Plastering — Plain and Decorative.

which is cut to the required depth, and t(i bear on the side screeds. The vertical screeds arc ruled
off with the circular rule, on which pieces of board cut to the desired depth and length of the
various jjanels have been previousl)- fixed. The inter\ening spaces are then ruled (^K w ith short
rules cut to the angular curves.

Another and better way is to cut an angular floating rule to fit the curve from A to a, and
float all the panel surfaces in a line from border to border in one operation. This angular rule
is set out in a similar wa)' as described for angle brackets. The rules for this or the first method
must be made to suit the longest line or set of jianels. After each set of corresponding jianels in
the other sides of the cupola is floated, the\- must be shortened to fit the next set of jianels, and
so on, until all the panels are floated. The mouldings being diminished in width, are run from a
diminished running rule fixed on a centre screed in the same way as described for diminished dome
mouldings. The screed for this method is formed b>' an angular floating rule cut to the angular
cur\e, as already mentioned. For some designs the moulding may be run with a twin-slippered
running mould. This form of mould can also be used for forming about I inch of the panel surface.
This acts as a ground for floating the panel surfaces. When large patera; are used, the ground
panel surface may be cast with them, thus avoiding floating and setting. The octagonal panels
shown in Fig. 4 are formed in a similar way to Fig. i. After the vertical and horizontal mouldings
are run, the diagonal sides of the octagons are planted. Where square panels form the design, the
mouldings can be run with a radius-rod running mould from a centre pin and block. The section
of the sofiRts of the arches are run with a radius-rod running mould, fixed on a radius board, and
the cross styles or mouldings, as shown at K and L, are planted. A small portion of the arch
should be run to form a ground on which the enrichments ma\- be modelled. Fibrous plaster is
well adapted for constructing the plaster lining of cupolas.

Panelled Beams. — When panelled beams have mouldings on the lower part of their sides
or faces, and on the soflit to form a sunk panel, they may be run in two parts. Screeds are formed
on the two sides, and one in the centre of the soffit. If the mouldings on the sides have more girth
or are larger than the portion on the soflit, the}- ma\- be run from rules fixed on the side of the
beam, with the nib bearing on the st)-le or on the soffits. If the style and mouldings on the soffit
are small, the mould is made to run the face, style, and soffit moulding in one. If the styles are
broad, the moulding on the sunk part of the soffit is run from a parallel running rule fixed in the
centre of the soffit, thus forming a double rule to run each side of the sunk moulding. The latter
way is most generally used. The end or other mouldings requirerl for panelling the soffit are run
down and planted.

All beams of any length should always have a camber, not onl>- to allow for an)- settlement
that may take place, but to make it more pleasing to the eye. A beam dead level and straight has
the appearance of sagging in the centre. This maj- be termed an optical illusion.

Trammels for Elliptical Mouldings. — It may at once be pointed out that an ellipse
and an oval are not the .same. Both ends of an ellipse are similar, and an oval is egg-shaped, one
end having a greater cur\e than the other, therefore the term oval moulding or panel is scarcely
correct when applied to the following illustrations. This term, however, is best known and
generally used by most workmen in the building trades. The term "elliptical " is generally applied
by plasterers when referring to mouldings where the whole ellipse is not carried round, such as for
mouldings on elliptical arches, windows, &c. ; and the term "oval," where the whole figure is
completed, such as panels (elliptical on plan) formed on walls or ceilings. In consideration of the
common usage of these terms, they will here be used in describing the setting out or working of same.

The Use and Construction of Trammels.

167

Trammels are often used for running oval panel mouldings, and for forming the lines when
setting out oval templates. Trammels are made of wood or metal. A simple way to make a
trammel for small work is to sink two grooves at right angles in a hardwood board (termed the
plate), about 7 inches long, 5 inches wide, and i inch thick. The grooves are about i inch deep
and i inch wide. Two hardwood pins are then made to fit the grooves. They have collars to
bear on the surface of the plate. The upper part is made round to fit the centre holes of the rod.
The subjoined illustration (Xo. 39) shows a template, and various sorts of template pins. Fig. i is
a view of a template, with the two pins, rod, with the running mould attached in position, and a part
of a moulding. Fig. 2 shows various sections of pins. A is the .section of the pin as used in Fig. i,
and C is the plan of the pin at the intersection of the grooves. B is the section of a dovetailed pin
used for another form of trammel. The rod is made to an>' desired length, so that it may ser\e
for various sized ovals. The average size for this kind of trammel is about I foot 6 inches long,
1 inch wide, and \ inch thick. A series of holes \ inch in diameter (to fit the head of the pin) is
made about | inch apart on the flat side. The first hole is made near one end of the rod, and
continued down the centre for about 1 5 inches, leaving the blank space
for screwing on to the running mould. A pin is now laid into each
groove, and the size of the desired oval is obtained by regulating the
length of the rod at each diameter by means of the holes. The pin in
the short groove is the point from which the length of the oval is taken,
and the pin in the long groove for the width. The trammel is fixed
on the running board by means of two or more screws, as shown.
This size of trammel can only be used for oval mouldings from about
10 inches to 36 inches at their longest diameter, therefore larger sizes
are required for larger ovals.

A trammel for running large ovals (say from 6 to 10 feet at the
major diameter), if made solid, as shown in Fig. i, would be too
heavy and cumbersome for fixing on ceilings, where the mouldings are
run in situ. A lighter kind, termed a "cross" template, is made as
follows :— Cut three flooring boards, one a little less in length than the
longest diameter of the proposed oval, and two less than the short
diameter. Lay them down on a floor in the form of a cross (similar to the
grooves in Fig. i ), and fix and brace them together
and allow the whole to be fixed on the ceiling. On the centre of this ground make two lines at
right angles to each other, and from these set out the width of the desired grooves at the ends and
intersections, and then fix wood fillets, each about i inch thick and 2 inches wide, to the marks,
thus forming the grooves. In order to prevent the pins dropping out of the grooves when the
trammel is fixed face downward on the ceiling, the inner sides of the fillets should be splayed so
as to receive dovetailed pins, as shown at B, Fig. 2. This may also be effected by fixing running
rules on the fillets so as to overlap about ] inch, over the groove space, thus forming rebated or
square grooves. The pins are made with shoulders to fit the grooves. In both modes a linch-pin
must be inserted in the trammel pin to prevent the rod dropping.

A strong, accurate, and permanent trammel can be constructed entirely with metal. To make
this, procure a sufficient length of metal tube, about \ inch in diameter, having a slot about i inch
wide, cut longitudinally. Cut the tube into four pieces, mitring the intersections, and fix and
brace them together in the form of a cross, as already mentioned. A pin made to fit the slot,

No. 39.— Tr.\mmei.s.
Four angular braces will hold them together.

i68 Plastering — Plain ami Decorative.

fixed ill a ball made to fit the tube, completes one of the sliding; pins. The rod maj- be made
of metal or wood, but the latter j^ives more freedom for changing the size for different sized ovals.

Various methods arc cmijlo\cd for running oval panel mouldings on ceilings. The most
useful are b>- means of trammels, or wtjod or ])laster templates. .A trammel is a good instrument
for running oval panels where the mouldings are not wide. Wide inouldings (say over I foot)
cann(Jt be run true or uniform in width in one operation with a trammel, because the running
mould, which is fixed on the end of the rod of the trammel, assumes a raking position when it is
between the right angle points of the major and minor diameters of the oval. This raking position
takes place at the four joints or change of curves of the oval, and is more pronounced in e.vtra
wide mouldings. This difficulty is overcome b\- running the moulding in two parts, using a trammel
mould for running the first or inner part, and a running mould (hor.sed to run on the run part) for
running the second or outer part. This is effected by dividing the section of the moulding into two
parts, taking care to make the joint at the side of a fillet or in the centre of a flat member at the
outer side of the part to be run w ith the trainmel mould, .so as to allow for a good bearing (wide and
strong) for the slipper of the running mould u.sed for running the .second part. The running mould
for the first part is fixed on the rod of the trammel as already mentioned. The running
mould for the second part is horsed with a circular slipper cut to fit the curve of the first moulding.
If the oval has quick curves, a slipper with two jiins will gi\c the best results.

If there is an enrichment in or near the centre of the moulding, run the moulding in three
parts, using the bed of the enrichment (which is run with a trammel mould) as a centre running rule
for running the outer and inner parts, which are run with circular or pin-slippered running mould.s,
as already described. It will be seen that b_\- using cither of these three methods, wide mouldings
for oval panels can be run uniform in width ; the trammel mould giving the form of the oval to the
first part of the moulding, or to the centre running rule, and the curved slippered running moulds
giving the desired uniformit)' of width to the full section of the moulding. Most forms of oval panel
mouldings are best run w ith templates. When run with trammels, or with radius-rods, the running
mould is apt to jump and cause cripples at the junction of the major and minor diameters.

TE.\IPL.\Ti:.S FOR RUNNING ElliI'TIC.VL MOULDINGS. — The true form of an ellipsis can only
be derived from the diagonal cut from the cone or the cj-linder, and the nearest approximation to
this curve must be obtained by continuous motion. There is no other instrument so well adapted
for effecting this purpose as a trammel. For a true ellipsis, make the distance from the outer end
of the rod to the nearest point or centre pin equal to half the shortest or minor diameter of the
ellipsis, and from the centre pin to the outer pin equal to half the longest or major diameter. This
shows the use of a trammel for setting out the lines to make a template for this form of ellipsis.

The subjoined illustration (No. 40) elucidates the method of .setting out another form of
ellipsis ; also an oval having its major a.xis one-third greater than its minor. This also shows the
template and a pin running mould in position for running an elliptical arch moulding. The
template (Fig. i) is made to e.xtend below the springing line of the arch, so as to allow the mould
to be run down to the spring of arch and save mitring. The template for running the arch extends
to the shaded part ; but to utilise the space the curve has been continued round to show a method
of setting out a template from which an oval moulding can be run, the oval having its major axis
one-third greater than its minor. The method of setting out is as follows : — First draw the line
A li, the greater diameter, to the desired length ; then bisect it, and erect the perj^endicular line
C D ; this line being the lesser diameter, is made a third less than the line A B. Then bisect each
half of the line, which will divide the line A B into four equal parts and give the centres E, E, which

The Use and Construction of Templates.

169

are the centres for describing the ends, as from F to F, and F i to F 2. Then from the centres
C and D describe the flat curves from F to F i, and from F to F 2, which complete the oval. It is,
however, better to set out this template by the trammel, as the junction of the segments of the circles
always has a more or less crippled look.

Fig. 2 shows a " pin-mould " in ]:insition when running an elliptical arch moulding. This
mould is provided with two hardwood jjins inserted into the bearing face of the slipper. The pins
bear on the edge of the template, and owing to their position, and being apart, allow the mould to
take an\- change of curve without "jumping."

Before running elliptical mouldings on arches or windows, the centres and running rods
should be tested, so that the mouldings will intersect accurate!}-, and s(j avcjid jumps at the change
of curves. All centre pins should be level with each other, and equidistant from the centre of the
arch or window. The outline and intersections of the propo.sed moulding can be tested hy
temporarih- fixing a pencil on the outer and inner profiles of the running mould, then working the
mould over the screeds, so that the pencils will form
two lines. I have heard of a three-centred elliptical
hood moulding being run over a window with what is
called a "bolted radius-rod." This rod is made in two
parts and connected with a hinge, and held straight
when running the long diameter with a Vjolt and
sockets where fixed at the joint. The running mould
is fixed on one end, and a centre plate on the other
in the usual wa\'. The long diameter of the moulding
is run first, and when the radius-rod reaches the change
of curve the bolt is drawn back, and the short diameter
of the moulding run with the short part of the radius-
rod. A nail is inserted in a board which is previously
fixed in the window opening. The nail must be fixed
in a line with the change of curve so as to stop the
radius-rod, and hold the long part in position while
the short part is working. The same operation is
repeated for the other side of the work. It is need-
less to say that this method is far too complicated to
be serviceable for general purposes.

Templates are useful for running most forms of elliptical panel mouldings. Plasterers ma}-
make their own templates or running rules by using fibrous plaster casts as a substitute for wood.
This is effected by first setting out a quarter of the proposed oval panel, then cut out or run a
tcmporar}' plaster running rule to fit the inner line, allowing a space for the slipper of a running
mould. Cut a reverse running mould to the section of the proposed fibrous plaster rules (sa}- about
I inch thick and 3 inches wide), then run the quarter length of the oval, and after making true
joints at the ends, cast four fibrous plaster quarters, and then la}- and fix them reversely, thus
comjjleting the full oval template or running rule. The full oval running rule can also be run
in situ and in one operation. This ma\- be done with a trammel or with radius-rods, according to
the form and size of the panel. Strong and stiff gauged plaster or a strong white cement, should
be used for the running rule, to enable it to resist the friction of the running mould while running
the moulding.

No. 40. — Temi>l.\te and Pin-Mould for Running
Ellii'ticai. Arch Mouldings.

170

Plastcritig — Plain and Decorative.

Radius-rods are mure often used for setting out the lines for oval templates than fur running
the mouldings. Circular mouldings — vertical, horizontal, or angular — run off circular grounds
require special running rules, so that they will take or bend to the double curvature. For this
purpose, cane, flexible metal pipes, and wooden rules, having series of saw-cuts on the backs and
sides, have been used, but cast fibrous plaster rules or a jack template are more suitable for most
of these purposes. Templates can also be made by means of a plasterer's oval.

Pl.asterer's Ov.\l. — The subjoined illustration (No. 41) elucidates the .setting out of this
form of oval to any given size, also the method of forming two oval mouldings from two circle
mouldings. The ovals are formed by running two circular mouldings in plaster, the diameter of
one being exactly double that of the other. Each circle is cut into four quadrants or quarters. Two
of the quadrants of the larger circle form the sides of one oval, and two quadrants of the smaller
circle form the ends, the four segments making a fairly good oval. The remaining segments
constitute another oval of similar size and shape. The method is simple and speed)-, and it can
also be employed for the formation of elliptical mouldings on arches, doors, or windows as well as for
oval panel mouldings. The formation of ovals bj- this method has been employed b\- plasterers

.\i>. 41.— bl.l 1 l.Ni. (Jl'l AND C^>.^.^lKlXlI.NO 1 'l.A.-< lUKlOUs OVAL.

for generations, but owing to the want of a definite rule for setting out this form of oval to any
given size, its use has been .somewhat limited. To meet this want, I have invented a method which
can be adopted for most purposes, and which I give here for the first time.* For want of a better
name, I have called this a " Plasterer's Oval," for the reason that plaster lends itself more readilj- than
any other material to the formation of circular mouldings. Xo one in the building trades can form
a circle or an oval moulding so quickly and accurately as a plasterer. The method of setting out
and of constructing this form of oval is as follows : —

To set out an oval to a given size, the greater diameter being given. Take this greater diameter
as a base to determine the required diameters of the large and small circle mouldings, M and X,
Fig. 2. Let the line A H, Fig. i, be the given diameter, say 3 feet ; on this form two squares, each
according to their diameter would be 1 foot 6 inches by i foot 6 inches, as shown at C D E K and
F (_; II C; then draw diagonals in each .square as at C E and D F and C G and V II and at their

* After the above was in type, .Mr Robinson informed me that this method of setting out this form of oval was
described and illustrated by \"ignola in 1563. Not having seen Vignola's work, I am unable to say if his method is
exactly the same as that given here.

The Use and Construction of Plasterer s Oval.

171

intersections I and i as centres draw the circles I K and I K. The radius in this evample would be
9 inches. The quadrants M and M I correspond with the same letters in Figs. 2 and 3, and they
form the two ends of the oval. After this take c as a centre, and with a radius from c to O at E or G
describe that part of the circle L from O L O, which forms the upper side of the oval ; now take F as
a centre, and with the same radius describe the lower side, joining K K at O and O, thus forming the
plan of the oval as shown by the line ALB, and the dotted line below C. It will be seen that the
respective centres to describe this figure give the centres and diameters to run the two circle
mouldings from which the o\'als are formed.

To construct the oval, first make a running mould to the desired profile, using a radius-rod in
the usual manner, for running circles on the flat. Before running the mouldings, set out two lines
at right angles on the moulding board, taking care to extend the lines a little beyond the outline of
the large circle, as shown by the dotted lines (Fig. 2). The extended parts of these lines act as
guides for cutting the moulding into exact quadrants. The intersection of them is the centre from
which both circles are run. Appl\- the running mould, and turn it round, so that it leaves a faint
mark on the running board to indicate the width of the moulding to be run. The width can also
be marked by the aid of a pencil, holding it at the outside member, and turning the mould round,
repeating this operation on the inside member. On this space drive in eight tacks, two in each
quadrant, leaving the heads projecting about \ inch. The object of these tacks is to prevent the
moulding from lifting owing to plaster swelling, or from moving round while being run. Cover the
tacks with claj- to allow the moulding to be freely taken up after it is run and cut. The moulding
is then run in the usual way, and is cut into four quarters or quadrants. This is done by applying
two set-.squares, one inside and one outside of the moulding ; and at one of the quarter lines lay a
straight-edge over the moulding and against the set-squares. The moulding can then be marked or
sawn at the proper place and angle. The dotted or quarter lines divide the mouldings into quadrants,
and give the angles for cutting them.

The use of extending the lines be\-ond the moulding will here be seen. A part ma\- be obliter-
ated while the moulding is being run, but the extended part will afford a correct guide for the outside
set-square. If the quadrants are cut fine, square, and clean, the joints will be scarcely perceptible
when the four segments are placed together. When this circle is cut and taken off the board, the
radius has to be altered to exactly one-half of the large circle, and the small circle is run and cut
precisely in the same way as the large one. The four quadrants can now be fi.xed to form an oval,
as shown in Fig. 3. If a quantity of oval mouldings be required, a casting mould can be taken off
this oval in which they may be cast. It will be seen that the quadrants X and N I form the sides of
the oval in Fig. 3, and the quadrants M and M I form the ends. It will also be seen that after com-
pleting this oval there are four quadrants left to form another oval. If but one oval is required,
run only one-half of each circle, allowing a little space beyond the centre line, so that a square and
clean joint can be cut. A thin saw with fine small teeth should be used for this purpose.

Fig. 3 shows the four segments of the moulding in position forming the oval. In this figure
the moulding is struck on the outside of the setting-out circle line, as shown in Fig. i, but the
moulding in Fig. 2 is struck on the inside of the setting-out lines. This is simply to show that the
same centres can be used for mouldings struck on either side of the lines.

A mould for casting oval mouldings, also templates, can also be made by the above process.
For this purpose a reverse running mould must be used for running the two circles. A plaster
piece mould for casting o\al mouldings that are undercut may also be formed by this method.
In this case the running mould must be made and used as described for " reverse moulds."

1/2 Plastering— Plain ami Dcconitive.

Coved Ceilings. — Coves to ceilings are of various heights, as one-third, one-fourth, one-fifth,
&c., of the whole height. The form of the cove is generally either a quadrant of a circle or of an
ellipsis, taking its rise a little above the cornice, and finishing at the crown or other moulding. If
the room is low in proportion to its width, the cove must likewise be low ; and when it is high, the
cove must likewi.se be .so ; by which means the excess of height will be rendered less perceptible.
An examjile of two coved ceilings (from designs bj- James Gibbsj are shown in the annexed
illustration (No. 42). F"ig. i shows the plan and elevation of a coved ceiling, with circular windows
between the groins. Fig. 2 shows the plan and elevation of a coved ceiling, the design of which
is less intricate than that of Fig. i. The curve of this cove is a quadrant of a circle, as shown
b)- the section at the side. The jjlans will enable the section of each design to be understood,
and viif vt'isA, and the whole will render the method of constructing coves and circular mouldings on

Plan.

Plan

No. 42. — Plans and Elevations of Coved Cem.ings.

circular surfaces (which is given hereafter) to be more clearly understood. The external and internal
angle mouldings in these coves may be formed with a jack template or as described for coves.

Circle Mouldings on Circular Surfaces. — The accompanying illustrations, Plates XL.
and XLI., are given to elucidate various methods of running circular mouldings on circular surface.s.
Fig. I (Plate XL.; shows the elevation of a cove suitable for an aquarium or marine hall. The
external angle rib moulding, c, and the panel rib moulding, D, spring from the top or weathering of a
main moulding, and intersect with a horizontal or crown moulding at the top of the cove. The section
of the horizontal moulding is shown at G, and the section of the jjanel moulding is shown above D;
the section of the external rib being of course double that of the panel moulding. Where circular
and straight mouldings intersect with each other, it is advantageous in most cases to run the
circular mouldings first, so that the whole of the moulding can be run, and leave the intersection to

Plate XL.

,l.ti..i.>l.liivi.'fc4*Mtf»<"i' j;4lt

'mmmmmm$wmmm$^^^^

Circular Mouldim.s on Circular Surfaces.

Fig. I.— Elev.\tion of S.mall Cove, with Sections.

Fig. 3.— Section ok Large Cove, with Section and Elevation ok Main Cornice.

Circular Mouldings on Circular Surfaces. '73

be mitred on the straight part, which is naturally the easiest part. In some examples it is not
advisable to run the circular part first. For example, if the crown or horizontal moulding, as
shown at G, Fig. i, was the lower part of a large crown moulding made to intersect with small
cove mouldings, it would be best to run the straight moulding first, and then cut away as much of
the straight moulding as will allow the nib of the running mould to pass while running the circular
moulding. For the section in this example there would be very little mitring to do, as it would
simply be a butt mitre up to the back of the circular mouldings. The external rib moulding, C, is
best run with a jack template. The circular panel mouldings (one-half of a moulding is shown at
d) can be run by two methods. By the first, the moulding is run in three parts, using a sledge-
slippered running mould fixed on a hinged radius-rod, and the two straight parts are run from
running rules. By the second method, the whole moulding is run at one operation by using a
fibrous plaster template, made as already described.

The circle panel, containing the head of Neptune, is run with a raised centre block, as shown at
M n, a plan and section of the panel. The use of raised centres will be seen later on.

The section of a large cove and main cornice (with the elevation of the cornice) is shown at
Fig. 3, on Plate XL., and the elevation at Fig. la (from A to B) on Plate XLI. In describing the
method of working this cove, the terms " section " and " elevation " will hereafter be used, instead
of referring to the numbers of the above plates. The main mouldings of the cove are the horizontal
or crown moulding at the top (as C H on the section, and A on the elevation), and the horizontal
or foot moulding at the springing, as at J M above the dotted line on the section on Plate XL., and
at B on the elevation (Plate XLI.), and the vertical or rib mouldings (as from J M to C H on the
section, and from A to B on the elevation). The terms " crown," " foot," and " rib " mouldings, being
generally emplo}-ed for the vertical and horizontal mouldings, will hereafter be used when
describing the setting out and working of same.

The oval, circle, and Gothic-pointed panels shown in the elevation on Plate XLI. are given to
illustrate the method of setting out and running the mouldings, and not as a complete design. In
order to render the setting out and construction more clear, the various lines and parts of the sections
and elevations are first described. The main ground section of the cove (indicated by shading)
springs from the weathering of the main cornice, as at J M, and terminates at H at Fig. 3. The crown
moulding, C H, is shown without a lathed bracket, so that the section and intersection with the rib
mouldings will be more clearly understood. The dotted line, J H, outside the main section is the
.section of the background of the circle panel, and the dotted line, \V M, is the section of the back-
ground of the pointed panel, the elevations of which are shown at Fig. 3^ on Plate XLI. These
lines, when continued in one line at the centre, as from J II to \V M, give the section of the back-
ground of the oval panel. The main section line of the cove (Fig. 3) taken from the star at J M,
in conjunction with the dotted line J H up to T B, and continued up to the cavetto of the crown
moulding under H, gives the section through the circle and pointed panels from dart to dart, as
shown on the elevation Fig. yx. The intersection of the circle and pointed panels is shown at T B
on the section Fig. 3. The oval, circle, and pointed panels will hereafter be termed circular panels.

The main cornice (Fig. 3) is ornamented with various enrichments, which are shown on the
.section and elevation of same. L is the bed and section of an enrichment sunk on the face of the
corona ; M is the bed and section of a frieze and truss ha\-ing side brackets ; X is the elevation of one
of the side brackets. The trusses di\ide the frieze into compartments ; this allows for a variety
of illustrative subjects. The animals which I have introduced, as a change from the ordinary foliage,
may be found suitable for a natural history museum or similar buildings. Q is the profile, and P the

'74 P/asfiV'iiii^ — Plain and Decorative.

cap of the truss. K is the bed and section of the architrave enrichment. The balls or husks at
S, which are part of the architrave, are cast separate!)', and fi.xed after the main part of the enrich-
ment is fixed. The main cornice is run from a nib rule fi.xed on the weathering, and a running
rule fi.xed on the wall.

The intersections of the enrichment in the rib and crown mouldings are sometimes stop[x;d or
further enriched b)' means of a pendent jjatera, as shown on the elevation (Fig. 3^, Plate XLI.).
When the enrichment springs from left to right, as shown in the centre of the circular panels, a
pendant is also used as a springing point. .A half section of the patera is shown at C M. The dark
[jart indicates the half section of the enrichment. The intersection of the enrichment ma\- also be
made b)- modelling ribbons over the mitres, as shown at .\ H, at the right hand or half rib. The
springing leaf shown near I! on the elevation is sometimes used to make a better and bolder
beginning for the rib enrichment. Another form of springing leaf is shown at F P. This has the
same section in the centre as the first sj^ringing leaf as shown near J M at Fig. 3.

With regard to floating, screeding, and running the cove mouldings, care must be exercised
when setting out and horsing the running moulds for the rib, crown, and foot mouldings, also for
the circular panel mouldings, so that they will intersect accurately with each other. The screeds
must also be made to intersect to allow the mouldings to be run true at their intersections. W'hen
crown and rib mouldings intersect together at right angles on the same ground section, as at C II,
Fig. 3, the intersection is easily made and pleasant to the eye ; but if the rib moulding intersects
with a crown moulding on a level ground, or where the outer members are square or perpendicular,
as shown at \V B, the intersection is not so easily made or so pleasant to the eye. The transition
from the circle to the straight, or in other words the intersection of the circle with the straight
mouldings, is sometimes formed in the bed of the enrichment, as shown at c on the section at w B.
Owing to a lack of attention in setting out the various running moulds, or in forming the screeds,
the ribs do not intersect correctly with the crown and foot mouldings. In this case the mouldings
have to be eased when the mitres are " put in " to make them more linable and pleasing to the e)'e.
This kind of mitring is then said to be "humoured."

With reference to the order of running the main mouldings, namely, the crown, foot, and
vertical mouldings, al.so the inner panel mouldings, such as the oval, circle, or pointed panels, the
main mouldings should be run first, so as to avoid mitring the panel mouldings, which being
circular on circular grounds, are more difficult to mitre than the crown and foot mouldings, which
are straight, or even the rib mouldings, which are only circular on section. After the main mould-
ings are run, parts of the inner sides are cut off to allow the nib of the running mould to pass when
running the circle panel mouldings. These parts are mitred and made good after the circular ]janel
mouldings are run. In order to avoid stuff falling on run parts, the crown moulding should be
run first, the ribs next, and then the foot moulding. The latter should be covered with old
paper or sacks, trj prevent stuff falling on while running the circular panels. The crown and rib
mouldings are run on screeds formed on the bed of the centre enrichment, as shown at R M, Fig. 3^,
which is a section of the moulding and the enrichment. The ribs are run in two parts — one running
mould will do for both — from a parallel running rule fixed in the centre of the section, as shown at
D K. The crown moulding is run in a similar way, but two different running moulds are required,
one cut for the inner and one for the outer section. The foot moulding is run in one operation, or
in two .sections, according to the size and form of the moulding. The main running mould for
both ways is horsed to run on a nib screed and a slipper screed. The latter is formed on the
weathering of the main cornice, on which a parallel running rule is fixed. This rule is also

Plate XLI.

J'Jf)Cx{AT£'o
353 £JX.

J^J-32

!itm'!i)fjawjEJ

J5Ji)

vv.y;i

;ui)£U)i

Circular Moui.uiM.b on Circular Surface^.

Fn; 2. — Co.MKixED Section and Elevation ok Cove and Panelled Fascia Mouldings.

Fig. 3a.— Elevation ok Large Co\e, with Oval, Circle, and Circular Pointed Panels.

Coiistmcting Circular Mouldings on Circular Surfaces. '75

used as a slipper rule when running the foot moulding, and as a nib rule when running the
main cornice.

Contrary to the order of working in ]3ractice, the method of running the various mouldings
has been first described, so as to make the method of screeding more clearly understood. The
screeds are based on a series of dots, which are made at the most suitable places. For the crown
moulding, the screed dots are made on the brackets at the bed of the enrichment, as already
mentioned. These dots are made across the bed, and each one must be made level crosswise, as
well as all being made level from end to end of the cove. As the crown and rib mouldings form
the base of the enrichment, the dots and screeds should be composed of gauged coarse stuff, so as to
give a sound foundation for the enrichments — in fact, all screeds for this class of work should be
formed with gauged stuff The first two dots are made on the crown bracket, one at each end of
the cove, keeping them level crosswise, and from end to end, as already mentioned. Two or more
intermediate dots, according to the length of the cove, are made, keeping them linable and level
with the dots at the ends of the cove. The screed is then laid and ruled off with a long floating
rule. A narrow screed is then made in a similar way on the bracket of the foot moulding. This
screed must be made on a member, on the same plane as the bed of rib enrichment, so as to form a
bearing for forming the rib screeds. This screed also acts as a nib screed for running the lower
part of the foot moulding, and a slipper screed for running the upper part. The joint between the
two is .set by hand.

Where the size or form of the moulding permits, the whole of the foot moulding can be run in
one operation from a slipper screed made on the weathering, and a nib screed made on the inner
surface of the cove. In this case dots are formed at the foot of each rib to act as bearings for
forming the rib screeds. The screed on the weathering must be made level from end to end of the
cove. The rib screeds are ruled off with a circular rule cut to the desired section, using the crown
screed and the foot screed or the dots, as the case may be, as bearings. Screeds for the nibs of the
crown, rib, and foot running mould must also be made. These screeds are also used for floating
the cove surfaces between the main and circular panel mouldings, as shown between the section of
the rib moulding, R >I, and the .section of the circular panel moulding, E (on the elevation, Fig. 3a).
These screeds and the floating of the angular surfaces are formed in the same way as described
for cupolas. The running rules for the crown and foot mouldings must be fi.xed equidi.stant, as
from .\ to B on the elevation. This is tested with a rod cut to the required length. The ruAiing
rules for the vertical ribs must also be fixed equidistant. This is effected by setting out the centres
of each on the crown and foot mouldings or screeds, as the case may be, from end to end of the
cove. This method, if accurately done, also gives a guide for fixing each rib running rule exactly
\ertical. This can also be tested by hanging a plumb-bob from the top marks, and applying a
large set-square at the marks on the foot screed, or by boning the cord with the eye.

After the main mouldings are run, a part of the inner sides, where the circular panel moulding
intersects, is cut off to allow the nib of the running mould to pass while running the circular panel
mouldings. The screeds at the top, bottom, and sides are made u]) with the aid of a gauge-rule,
made to bear on the run parts. The circular panel moulding being run with a radius-rod or on a
template, the running mould is cut to run a part of the inner ground of the panel, and is horsed with
a slipper on the outside, therefore an inner screed is not required.

The construction of circular mouldings on circular grounds requires special methods, especially
if the}' intersect with other mouldings, as shown in the present example, so that thej- will be true and
intersect accurately. A circle moulding run on a circle ground with a radius-rod running mould

1-6 Plasf eying — Plain and Decorative.

would iici be a true circle on plan. The curve at the spriii'^ing and crown of the circular j,'round
would be flat, and have the form of a stunted oval. This difficulty is overcome by various methods.
One is by raising; the centre i)in in- means of a block. For e.\ample, take the section of ihc circular
panel at J II, on the main .section of the cove (Fiy. 3). The chord line, J S, is taken from the arris of
the member of the mouldin-,' which touches or meets the corresponding member of the foot moulding,
and up to the same member above, as at T H. If the centre pin was fixed on the ground surface at
the dart of the horizontal line indicated b\- the dotted line at J s, the radius-rod would then form a
true circle on the horizontal line, but the circle would be flat on the vertical line. If the centre was
raised, say to X, the radius-rod would decrease the diameter of the circle at the horizontal line, but it
would extend the diameter at the vertical line. Therefore in order to allow the circle moulding to
be run true or intersect with the square panel mouldings, the height of the centre and the length of
the radius-rod must be regulated until the desired ]X)ints at the horizontal and \ertical lines are
equalised. The oval panel shown on the elevation (Fig. 3rt) may also be run with a template. To
make a template for this purpose, first make a flat template to the desired size of circle on plan,
then la\- it over the circular ground, and project the circle on to the ground, then from the projected
line or points form a plaster template or running rule on the ground. The pointed panel is run with
the aid of a radius-rod and two centres. The oval panel may also be run with a template made as
described for the circle panel.

Another way (that I have introduced for this purpo.se) is by the aid of a "trammel-centre."
With the use of a trammel-centre, the oval moulding is run with a radius-rod working from a
miniature oval formed in the trammel-centre and fixed at the intersection of the right angle lines of
the major and minor axes. The trammel-centre is made by first setting out on a board (called .
the centre board) a small oval made to the scale of the full size of the proposed o\al, then cutting
out the oval, and fixing the board on two blocks to act as a raised centre. The centre pin is inserted
in the centre board, and held in position with a sliding board on the to]} to pre\ent it from falling
down, and with a sliding board on the under side to prevent it from rising, thus allowing it to work
freely and bear on the rim of the oval. The method of construction and working is further eluci-
dated b\- the sketches at Fig. 4. Plate XL. This shows the end section of the trammel-centre, with
the radius-rod and running mould attached. H, U, are the blocks on which the centre board is h.xcd, and
the lines at X, N, indicate the narrow width of the o\al in the centre board. The two blocks form a
raised centre, and allow the centre pin, r, to work freely. The centre pin is circular on |)lan up to the
top surface of the centre board, where it becomes square, to allow of its being readil)- and strong!)'
fixed into the upper part. This part forms a sliding board which bears on the centre b(jard. The
centre pin is prevented from rising hy means of the sliding board, S, and further secured bj- means of a
linch-pin, L, inserted through the foot of the centre pin. The radius-rod is jointed, and connected
with a flajj-hinge, to allow the running mould to negotiate the various cur\es b\- rising and falling.
In this sketch one-half of the hinge is shown fixed on the under side of the radius-rod, and the other
half on the upjier side of the radius pin, as shown at R — this is really a part of the radius-rod — to
allow the running mould to fall or work below the level of the centre if required.

Fig. 5, Plate XL., is an enlarged view of the plan of the upper side of the trammel-centre.
O is the centre board, K the sliding [jart of the radius-rod, with the square head of centre pin, P, and
connected to the long part of the rod. In this sketch all the hinge is fixed on the upper side of
the radius-rod. Fig. 6 is a perspective view of the centre board. A, and the blocks, B, I!, before the
centre pin and radius-rod are inserted. F"ig. 7 is an enlarged view of the plan of the centre board,
showing the centre pin, P, in three positions, as it works round and against the edge of the oval centre.

Moulds for Circular Mouldings ou Circulate Surfaces. ^77

Fig. 2, Plate XLI., shows the section and elevation of a cove, with a long segmental rib moulding
springing from the weathering of the cornice above a panelled fascia, and intersecting with the crown
moulding of the cove. The crown moulding is run first and the rib next. The crown moulding is
run from a slipper screed formed on the cove, and a nib .screed formed on a ceiling or on the outer
member of the mouldings, which may be on the fascia of a lantern light, according to the design.
The rib moulding is run with a radius-rod from a raised centre. The part of the crown moulding
which intersects with the rib moulding must be cut off to allow the nib of the rib running mould to
pass. This part is mitred and made good after the rib is run.

The cornice above the f;iscia, the upper and lower longitudinal mouldings of the sunk panels of
the fascia, and the soffit, are run in two parts. The upper part is run from a running rule fixed on
a screed formed on the ground of the sunk panel, as shown at \V, and a nib rule fixed on the
weathering of the cornice. The lower part is run with a " hanging mould," J M, from the same
running rule, W, as used for the upper part, and a nib screed formed on the soffit. The styles, C, are run
down or cast,' and then planted. The lines at the top and bottom of the style, C, indicate the joints
of the planted part before they are stopped. In some examples the mitres or angles of the panels
take the form of moulded curves. Three examples of moulded angles are shown in the sketch.
Moulded angles are made after the panel mouldings are run. If they are of an intricate design, a
model of one is made and then moulded, cast, and planted ; but if of a simple form, they are formed
in situ. This is effected by cutting a template to the desired section, and fixing it temporarily in
position at the angle, and then filling in the space with gauged stuff Another way is to lay a little
over the desired section with stuff, and then apply a template over the stuff, and use it as a guide for
cutting the section. The combined plan and section of a template for forming the angles of the
fifth panel is shown by the shaded part on that panel. The names of eminent men in art, science,
and literature, with the dates of their birth and death, in the sunk panels of the fascia, are instruc-
tive as well as being decorative. The names and dates may be stamped in the soft plaster, or
cut out when it is hard. They may also be cast on a ground, and then planted. The half elevation
and section of a moulded pilaster is shown at M P. Moulded pilasters are sometimes used to divide
a long series of small panels into compartments, and sometimes to act as a support for overhead
mouldings. The pilasters are cast, and then fixed after the mouldings are run. The cove enrich-
ments are generally cast with a background, and then planted after the mouldings are run. For
small work, the rib and crown mouldings and the enrichments can be cast in one piece. The work
done by this process is not so linable, and the joints are apt to be more or less noticeable. Joints
in enrichments are not nearly so noticeable as those in mouldings.

Mouldings circular in form and circular on plan, elliptical or diagonal mouldings on arched or
coved ceilings, or on concavo-convex surfaces, require special forms of running moulds, so that the
slippers and nibs will bear and run accurately on the .screeds and form the mouldings true and
without "jumps." The short o\aI nib slipper for Gothic ribs has already been described. Another
kind of slipper, termed a sledge, is particularly useful, and may be relied upon to work irregular
cur\'ed surfaces without broken lines or jumps. A side view of a sledge-slipper on an irregular
cur\ed surface is shown at J (; on Plate XL. The nib — termed a "bull-nose nib" — for a sledge-
slippered running mould is rounded off so as to present onl>- a small bearing surface. A side
.section of a bull-nose nib is shown at A M, and an end section at II 1?. Another nib which will fit
an)- curve is formed by the aid of a patent castor. This is simply a metal ball working inside a metal
cup, the end of the cup being cut off so as to allow the ball to work on the ground or screed. A
running mould for concavo-convex surfaces is described and illustrated in ChajHcr XI.

i/'S Phisterwg— Plain and Decorative.

The decorative plaster work tiispla\eil in IMates XL. and XLI. can be executed by two methods,
the first bj- "direct nnxlelling" or modelling; in silii, and the second bj- moulded and cast work. It
is sometimes of advantafje to execute work /// silu, but the modeller or plasterer must in his own
mind balance the advanta<,'es and disadvantat^cs of this method over moulding and castmg.
Although these processes have been fully described in Chapter \'III., it may be advisable to refer
to them here (as the work is illustrated) in order that their respective merits be full\- known and
appreciated.

With the exception of the half-round enrichment in the rib and crown mouldings, and the
enrichments in the main cornice (the frieze excepted , all the ornamental work, human and animal
figures, foliage, flowers, fruit. &c.. in these examples, can be most effectively modelled /// situ. If the
work is carried out in this wa>-. the effects of light and shade and balance when in position ma>^ be
better observed, and defects readilj- adjusted, and a greater variety of design and details can be and
is generall)- emplo\ed in this method, but expense of course must enter into the calculations of the
modeller, although in high-class work this is not always a matter of paramount importance. The
question of cost is generally regulated by the importance of the building. Of the two methods, it
will often be found that work modelled //; situ costs less than cast work.

In the first method, the work is modelled direct, and the cost thus minimised ; whereas in the
second method— cast work— the piece has not only to be modelled, but also to be moulded, cast, and
fixed. In the examples given — as well as in the majority of works of this kind — the design has to
be m(5delled in .sections, and often some of these sections must again be cut into several pieces, each
requiring to be separatelj- moulded, cast, and fixed, thus enhancing the cost of the work b>' the cast
process, which is, therefore, only the more economical for small work, or where there is a considerable
amount of repeated work to be done. Ornamental work modelled in situ has one decisive advan-
tage over cast work, inasmuch that it cannot be reproduced in inferior buildings, as is unfortunatel\-
too often done with cast work.

FOKMiNc; XICMK.S. — Xiches are recesses formed in walls, sometimes for the purpose of placing
some (irnamental object in them, such as statues, va.ses. &c., and the)- are often constructed in thick
walls in order to save materials. The plans or bases of niches are generally semicircular, but some par-
take of all the .segments under a semicircle, while others are elliptical, and in a few instances they are
square or rectangular. The elevations of niches are generally in accordance with their plans, but varia-
tions from this rule are sometimes met with. The crown or heads of niches are generall)- plain, but
they are .sometimes enriched with .scalloped .shells, &c., or panelled with mouldings. With respect to
the proportion of niches there is no fixed rule, but the general one is twice and a half their width for
their height. Various methods are emploj'ed in the formation of niches. The crowns of circular
niches are generalh- run with a mould, because being circle on circle and small in surface, it is
difficult to finish them true and smooth by hand.

The accompanying illustration (No. 43) elucidates two methods of forming semicircular niches
with the aid of running moulds. Fig. I shows the elevation, and Fig. 2 the section of the crown
and a part of the body of niche, with the centre-boards and moulds in position when forming
the crown of the niche. Fig. 4 shows the section of the bodj- of the cove, with the mould
in position when forming same. By the first method the niche is formed in two operations,
and by the second method it is formed in one operation only. For the first method, cut a running
mould to the section of the niche, as shown at B. Fig. i, then fix it on the centre board. A, with two
hinges, keeping the upper surface or mould plate level with the top edge of the centre-board, as
shown on the section of the niche, Fig. 2. This al.so shows the end section of the centre-board and

Forming Niches with Moulds.

179

the mould, with the mould plate and a hinge. The dotted line indicates the distance the mould

travels. After this, fix the combined centre-board and mould on the wall, taking care that the top

edge of the centre-board is level and exactl>- at the springing of the crown, C. The face of the wall

must be floated plumb, and an allowance made by means of dots for the thickness of the setting

coat before the centre-board is fixed. After the crown is finished, the centre-board and running

mould is taken off the wall and separated. The mould is then horsed with two slippers to allow of

its running the bod}- or vertical part of the niche. The mould works on a running rule fixed on one

of two screeds which are formed on the face

of the wall, one on each side of the opening.

Care must be taken that the screeds are

plumb with the centre-board dots. Fig. 3

shows an elevation of the mould when

horsed. B is the mould, D is a connecting

board on which the mould is fixed b)- means

of the cleats C, C, and F, F are the slippers.

Fig. 4 shows an end section of the horsed

mould in position when running the bod)-

of the niche. The base is finished by hand.

By the second method the niche is run
in one operation, as alread}- mentioned.
This is effected by cutting a running mould
to the vertical section of the niche, then
fixing a pivot at the bottom and a bolt at
the top. A wood block, with a socket to
fit the bolt on the mould, is let into the face
of the wall at the top of the niche and
temporarily fixed, then another block with
a socket to fit the pivot of the mould is
fixed at the bottom of the niche. Care
must be taken that the sockets are plumb
and in a line with the centre of the niche,
also that they arc in a line with the face
of the wall, so as to allow the mould to
form a true semicircle with perpendicular
arrises. Place the pivot of the mould in
the socket, and push the bolt up and secure
it, and the mould is ready for working.

Fig. 5 shows a section of the niche with the mould in position. A is the mould with the pivot
and bolt, and B, B, are the socket blocks. A plan of the niche and mould is shown at Fig. 6. This
also shows the plan of the pivot block, and a board which is sometimes used to secure the block.
The dotted line indicates the distance the mould travels. When there are splays or beads on the
angle of the niche, the crown part is run with a radius-rod mould from a centre-board, and the
vertical parts with a " twin-slipper running mould " on running rules fixed on the wall screeds,
or with a nib running mould on a slipper and a nib running rule.

The \-ertical parts of the beads or spla\-s maj- also be run with the mould shown in Fig. 3.

No. 43. — FoR>MNG Niches with Running Moulds.

'So Plastering — Plain and Lh'corative.

Yox this |)iiri)()si.- twn plates cm tn the desired section must be fixed on the mould, one at each side.
The crown part is run with a radius-rod, as alread)- mentioned. Tlie crown surface and the an<jle
mouldinu can also be run in one operation. This is effected by cutting a mould plate to the section
of the moulding, including the section of the crown surface, then horsing it with a slipper to run on
the wall surface, and a pivot to fit a socket formed in a centre-board, or with a radius-rod to work-
on a centre-board. A pivot will be found most suitable for small work, and a radius-rod for large
work. In either case they must be fi.xed on the centre of the mould, so as to be in a line with the
mould plate. After the crown is run, the mould |)late of the crown surface is cut off, and the
remaining jiart of the mould u.sed for running the vertical mouldings.

In some designs a small moulding, such as an impost moulding, is carried rinmd the body
surface of the niche, and in a line with the springing of the crown. This moulding can be run in a
similar way as shown at Fig. 5, or by fi.\ing a flexible wood or a plaster running rule on the body of
the niche for the mould to run on.

The crowns of niches that are panelled w ith small mouldings are best executed by making a
model of the design, then moulding it, and casting and fixing as many as are required. In niche
crowns that are enriched with shells, foliage, &c., the enrichment should be cast with the crown
surface as a background. Fibrous plaster is well adapted for the construction of niches. For this
purpo.se a reverse casting mould should be emploj'ed for ft)rming the casts. This is made by cut-
ting a reverse running mould to the section of the niche, and after a sufficient length of the botly
is run, cut the mould in half and run the crown. Then fi.x it on the end of the run body, and then
fix rules at the sides and ends to form fences and rims, thus completing the casting mould.

Any of the above methods for forming niches with running moulds can be advantageously
u.scd for forming the body and crown of the Ionic niche, which is described and illustrated in
Chapter VII.

CHAPTER VII.

EXTERIOR PLASTERING.

Portland Cement Facades— Methods of Working Portland Cement Facades— Running Portland
Cement Mouldings — Fining— Sand for Fining — Coloured Cement Facades — Preserving
Plastered Facades- Fixing Points for Metal Appliances— Pediments— Pitch of Pediments-
Raking Mouldings— Raking Modillions- -Setting Out and Plastering Doric Porticos, Ionic
Niches, Pedestals, Open Pediments, Block Cornice and Quoins, Columns and Arches, Balus-
trades, Plain and Ornamental Balusters, Pierced Work, Windows, Window Heads, Dormer
Windows, and Elizabethan Gables— Rough Cast--Sgraffitto— Fresco— Indian Fresco and
Marble Plaster— Impressed Plaster Work.

Portland Cement Fa(,'ADES. — About half a century ago the exteriors of brick, and sometimes
stone buildings, in many districts of the United Kingdom, especially in London, were plastered
with Portland cement. The back and end elevations are more or less plain, while the fronts are
of a more elaborate nature, representing stone work in all styles of architecture. These are still
in existence and in good condition, which show the durability and adaptability of Portland cement
when properl)' handled b}' competent plasterers. These fronts compare favourabh- with stone
work of the same age, and it is a well-known fact that Portland cement wears better than Bath
stone. Consequently it has been largely used for casing decayed stone fronts as well as brick work.
There are miles of streets in the West End of London where nearly the whole of the facades are
either plastered with Roman or Portland cement. Roman and other cements were in general use
about a century ago for plastered fronts. Regent Street and numerous terraces around Regent's
Park, designed by Nash, had plastered facades. Fine examples of Roman cement facades are to be
seen in Chester Terrace and Gloucester Terrace, Regent's Park. Some of these fa9ades are enriched
with massive fluted columns. Iron fluted collars, one for the base, one for the middle, and one for
the top of the column, were temporarily fixed on the brick core as guides for ruling in the columns
and flutes. This work was done by H. Mott, the grandfather of the present H. Mott, Clerk to the
Worshipful Company of Plasterers. The foreman was S. Wright. Owing to the unequal manu-
facture of Roman cement, some of the work executed with it, after a {^i\\ \-ears' exposure, showed
signs of decay, which brought the use of cement for plastered fronts into evil repute. On the
introduction of Portland cement, plastered fronts again became fashionable, and the use of Roman
cement, except for inferior class of work, was abandoned. In a few instances Portland cement
scaled in parts, but this was due to the unequal qualit\- of earl_\- manufacture, and also owing to
the inexperience of some workmen of the then new material. At present the manufacture is far
more equal and reliable. This fact, combined with the greater all-round knowledge and experience
in the manipulation, causes Portland cement work for facades to be safe, strong, sharp, and durable.

Among the man\- fine examples of Portland cement facades in London, the following ma\- be
noticed : —

Alexandra Hotel, near H\de Park Corner. Here it can be seen in all forms, as figures, foliage,

1 82 Plastering — Plai)i and Decorative.

vermiculated work, and other features generally reserved for stone work. This beautiful facade
rivals most kinds of stone in colour, and shows no sign of flaw or crack. T. Hass was the master
plasterer, W. Hawkins the .scaffold foreman, and \V. Hatt was the shop foreman on this unrivalled
work. The offices of the old Metropolitan Board of Works, Spring Gardens, is a striking example
of Portland cement fronts. C. Lane was the foreman plasterer.

Another excellent example of Portland cement faqades is to be .seen at Campbell's Observatory,
in the King's Road, Chelsea. This work is remarkable for its uniform colour and texture. This
exquisite example of Portland cement work was executed b\- Messrs Parsons, a high-class firm of
plasterers, now defunct. G. Scarle was the foreman plasterer, and the modelling was executed by
R. Hanwell and the author. Some of the adjoining shops, although not so fine in the manipulation
of the cement work, contain some effective modelling by VV. Doyle. The facjades of the houses at
Lancaster Gate are plastered with Portland and Sheppe\- cements, Sheppc>- being used for the
mouldings and cast work, and Portland cement for the walls and plain work. John Helm was the
foreman plasterer.

.\n admirable example of a Portland cement faqade is to be seen at the United Service Club in
Pall Mall, with its rich frieze in the main cornice, al.so the pediment and fluted columns. This
effective modelling is by T. Garland, J. Main being the foreman plasterer. The Athenaeum Club
is another example of the utility of Portland cement, a prominent feature being its handsome
cornice and equestrian frieze. This work was carried out under the supervision of J. Parish, a
London plasterer. Another example is the Travellers' Club, designed by Charles Barry. The
modelling was done by T. Garland, T. Sidwell being the foreman plasterer. This work is not up
to the standard of that in the above-named clubs, which may be accounted for b\- the fact that the
work was carried out by the builder, while the others were carried out by master plasterers. ALiny
stone fronts in the same district and of more recent date than the above-mentioned examples of
Portland cement fronts already- show signs of decay and lamination.

A highly interesting and curious combination of stone, brick, and cement work is to be seen
in the facade and ends of the Grosvenor Hotel, London. The greater part of the mouldings and
ornamentation on the exterior of this noble building is composed of Portland cement and Sheppey
cement in the proportion of i part of the latter to 3 parts of the former. The Sheppey was used to
accelerate the setting of the Portland cement. One part of this cement mixture was gauged w ith
3 parts of very coarse sand and small shingle. The whole of the enrichments for the exterior,
and the plaster decorations for the interior, were modelled by T. Garland, and G. Dickens and
J. Wheeler were the foreman plasterers for the exterior and interior work, the whole being done
under the supervision of " Nobby " Rodeford, a notorious London plasterer. So close is the
resemblance of the cement work to the stone, that only the closest scrutiny will detect the difference
in grain and colour. It is difficult, even for an expert, standing in the street and looking up at the
facjade, to point out which is stone work and which cement. It will be interesting and instructive in
the future to note the properties as to colour and wear, and observe the effects of the London
atmosphere on the three materials, stone, brick, and cement, with which the exterior of this edifice
is constructed and decorated.

Unusual opportunities are to be found in Victoria Street, Westminster, London, for comparing
the wearing properties of plastered Portland cement and cast concrete with that of stone, brick, and
terra-cotta. Besides the facades wholly cement-fronted, there are other buildings where the
structural brick work is faced in some parts (such as the main cornice, window, and door mouldings,
&c.) with Portland cement, while in others stone forms a part of the faqades. These cement-fronted

Portland Cement Facades. '§3

buildings in Victoria Street testify to the adaptability and durability of Portland cement, and
compare favourably as regards colour and wear with adjoining stone buildings. These cement
fronts contain some fine examples of T. Garland's modelling.

The Westminster Palace Hotel, erected in i860, where, after completing the decorative models,
I made my maiden effort in the manipulation of cement work under the guidance of J. Towser,
is a fair example of Portland cement facades. J. Silvester was the foreman plasterer. Excellent
examples of I'ortland cement facades are to be seen in the additions to the Euston and Paddington
railway stations. These works were executed about two decades ago by Joseph Bickley, one of the
few master plasterers in London. Victoria Street also contains a range of buildings, a great portion
of which is constructed with cast Portland cement concrete of a Mansfield stone colour. This
work was executed in 1883 b\- W. H. Lascelles, and the exquisite modelling by P. Thomas and
J. Humphreys. Another example for future comparison as to the relative merits of wear and
durability of cast concrete and terra-cotta is to be found in the three top bay windows of the
Joint-Stock Bank, \'ictoria Street, where a part of the main cornice, baluster, base, rail, and string
mouldings used in a recent addition are composed of cast concrete coloured to imitate the terra-
cotta which forms the dressings of the original edifice. The concrete casts can be distinguished
from the terra-cotta, the former being double the length of the latter. This work was executed in
1890, by J. G. Smyth, under the author's supervision.

On a few of the old Portland cement fronts here mentioned there are several small portions
where the fining has scaled. This is due to the work being done in hot weather without properly
saturating the surface ; also to the floating being too smooth and dry. These surface defects can
be repaired, leaving a strong and solid body. Stone or brick which laminates can only be repaired
by cutting out the entire block or brick. The rapidity with which Portland cement can be repaired,
and its ultimate strength, is a decided advantage in its favour for facades. Although stone and red
brick fronts are now the fashion, the utility of Portland cement must again be recognised by the
architect, both for new fronts and encasing old stone and brick work.' It is certainly more damp-
resisting than either stone or brick, and it can be coloured to any desired tint, or enriched by car\'ed
cement work as well as cast, thus avoiding repetition. Plain surfaces may also be decorated both in
line and colour with sgrafifitto, and with coloured stone flints, glass, &c., as used in depeter. Portland
cement has no rival positively as a structural material for most building purposes. It is unrivalled
for e.xternal plastering. Its strength, tenacity, and adhesi\e power give support to a wall, instead of
a dead weight ha\ing to be carried. It is absolutely the best material for resisting vermin, damp,
and fire. In fact, of all mortars or cements that have been used for plastering the e.xterior wall
surfaces of buildings, Portland cement is unquestionabl>- the best plaster material for this purpose
produced in this century or an\^ other. No other material, whether used monolithically or as a
casing for stone or brick work, will resist the action of our variable climate like Portland cement.
Objections have been raised against its cold colour, but this is simply the colour of the natural stone
from w hich it takes its name, and the objections may be overcome by colouring it as already
mentioned. Even when begrimed by age, it is superior in point of endurance and damp resistance
to porous stone. It certainly looks better and more pleasing than a brick facade with a network of
unsightly joints, and Portland cement facades, when dirt}-, can be cleaned and coloured at a less cost
than stone, or repainting brick fronts. In case these comparisons should convey the impression
that I put forward Portland cement work as a substitute to be preferred generally to stone or
bncks as a finish for facades, it is perhaps necessary to say that I disclaim any such intention, and
to explain that what is claimed for it, and can well be demonstrated, is that in all ca.ses where stone

iJ^4 Plastcritii: — Plain ami Decorative

is soft, or bricks inferior, it wouici be wise economy to exhaust the possibilities of Portland cement
with and without colour, before using unsuitable stone or bricks. Havinjj regard to the increasing
scarcity of good stone, it is safe to predict an extended use in the future for Portland cement fa9ades.

Methods of Workixi; Portland Ckmknt Fac^ades. — Considerable conflict of opinion
prevails as to the best method of using Portland cement in the formation of mouldings and plain
surfaces on the facades of buildings. The directions here given are based on experience and
successful practice, not onl}- of mj- own, but also of others who are leading lights in plastic arts,
and who have made the subject a life-long stud)-. The first and original process is by the use
of permanent screeds, that is, the screeds for plumbing and running purposes constitute a part of the
floating. This process is the most general in use. The second process is by the use of temporary
screeds formed with plaster. This method is one which I have introduced with considerable success.
It has been termed the " plaster screed process," to distinguish it from the first mentioned, which is
termed the " permanent screed process," and is performed as follows : —

Permanent Screed Proce.^s. — The first necessity for all Portland cement work is good
cement, which should be tested and air-slaked, as described for Portland cement in the chapters on
" Materials." As many tons should be ordered as floor-room can be found for. or the approximate
requirements of the job demand. Only use clean sharp river sand where it can be obtained,
and clean shingle passed through a ]-inch sieve or screen, mixed in the proportion of i part
of .shingle to 3 of sand. The above are the requisite materials for roughing out or floating.
Crushed shingle is better than the round pea shingle. Crushed stone or granite is even better than
shingle, but stone being of a more porous nature, it must be thoroughly wetted before using. Lime-
stone or other hard stone is best for this purpose. The materials should be accurately measured
with a bottomless box, in the proportion of 5 parts of mixed shingle and sand to 2 of cement. Turn the
whole over twice in a dry state with a shovel, and thrice after the water is added. Special care must
be taken not to put in too much water, or the result will be a too soft gauge, and therefore more
cement and sand will have to be added to make it of the proper consistency. This should be like
well-tempered "coarse stuff" The whole of the front should be cleared of all building mortar, and
the surface well swept with a coar.se broom, and then thoroughly wetted until the absorption of the
brick work is completely stopped. Cement adheres and eventuallj- becomes much harder when laid
on a damp surface than if laid on a dry or porous one. Hence the importance of careful and
thorough wetting. The joints of new brick work, or where there is a suspicion of unslaked lime
particles in the joints, should be raked out and then swept and wetted.

Large surfaces of smooth stone work should be hacked to give a key for the cement. After the
wall surface is cleaned, the front of the building must be plumbed. This is done in a similar way
to that described for lime plastering in Chapter IV., but with the following additions :— The two ends
of the building are plumbed first. A plasterer at top of one end lets down a line long enough to
reach from top to bottom of the building, with a heavy plumb-bob at one end of it, to a plasterer
at the bottom. Each man must have a wooden gauge of exactly the same length, and long enough
to clear all projections. The top man drives a strong nail into a brick joint, allowing the head to
project about \ inch, and places the gauge with the line on the head of the nail. The man at the
bottom drives in a nail, then steadies the plumb-bob with one hand, while he applies the gauge
with the other hand on the head of this nail. This bottom nail must be driven in just so far
that the steady line will strike the bottom gauge exactlj' on the same place as it is suspended
from the top one. If there are no projections at this particular spot, the top man may fasten
his end of the line on the head of his nail, and the bottom man will do the same, and then

Floating Portland Cement Fagades. 185

the intermediate nails can be driven in exactlj- to the line from top to bottom of the building.
The intermediate nails consist of one nail at the top and one at the bottom of each storj-.
If there are projections which prevent the line being used in that way, a third man is required
to assist with a gauge of the same size as the other two; and while the top and bottom
men hold their gauges on the heads of their respective nails, the third man knocks in the
intermediate nails exactly to his gauge from the line. All nails must be kept about i foot away
from the projections, to allow free play for the floating rule when forming the screeds. The same
operation is repeated at the other end of the building, which gives two vertical lines, from which
all other lines are formed. Horizontal lines at the top and bottom of each stor>' are next
formed. If there are no projections to interfere with the free course of the line from end to end of
the building, the line can be fastened to the heads of the end nails, and then the intermediate nails
knocked into the line, about 9 feet apart. If there are projections, the men will have to adopt
the same method as before described. These lines of nails give the positions and bearings for the
screeds, which form the groundwork of a perfectly upright and straight front. Whether it is
altogether plain, or is embellished with ornament or mouldings, this method of planning out is
equally necessar}-.

Before laying the screeds, it may be desirable to thoroughly wet the surface again,
especiall)- if the weather is warm, or sun rays fall on the work. The screeds should be narrow,
not wider than the thickness of the floating rule. After they are laid, do not be in too great
a hurry to follow on with the rule, or the screeds will shrink ; but when the stuff is somewhat firm
rub the rule gently down on to the head of the nails, thus leaving a firm screed, not liable to
shrink. Where practicable, the whole of the screeds should be laid first, as sometimes the nails
get accidental!}- knocked out of place. This method also gives more time for the screeds to get firm
before being ruled off. When the screeds are hard enough to bear the floating rule, begin and lay
the whole of the front, and rule the surface in with a floating rule. The floating rules must be
made sufficiently long to reach from .screed to screed. If there are any deep parts on the surface,
it is not advisable to fill them in all at once, but rough them out first, and when firm or nearly set,
follow on with the floating. The floating stuff should be applied as quickly as possible, and with
little manipulation, and then the floating rule worked with an up and down slanting motion, so as
to cut off any excess stuff, and leave a rough surface. The rougher the finish of the floating, and
the less labour applied to it, the better ; the process of setting is less disturbed, and a stronger key
is obtained for the fining coat. On the roughness of the floated surface depends the success or
failure of the work. The adhesive power of Portland cement is great when used neat, but of
course the adhesion is decreased by the addition of sand. It is therefore necessary to obtain the
best possible ke}- for the fining coat. The key left by the rule on the floating surface may be supple-
mented by means of a nail float, or by a large nail, which is worked in a circular motion over the
surface, or still better, by the use of a sharp, wide-toothed drag.

RuxxiXG Portland Ce.ment Mouldings. — When the floating is completed, the mouldings
are run. The nib of the running mould for the main cornice should not project more than i inch on the
weathering. A line, parallel with the drip, or most prominent upright member, should be formed with
a saw on the stock to act as an indicator when plumbing the mould with the plumb-bob, as shown
in the annexed illustration (No. 44). This shows a section of the mould, wall and nib running rules,
stone bracket, and blocking over the main cornice. In all mouldings of this class there are two kinds
of running rules required — one for the slipper of the mould, called the "slipper" or wall rule, as shown
at \V, which is fixed on the wall screed F ; and one for the nib, called the " nib-rule," as shown at N.

■ 86

Plastering— Plain and Decorative.

The slipper rule should not be less than 2\ inches wide and I inch thick, and there is nothing better
than straitjht floorinj; boards for the nib-rules. I'roceed to fix the running rules b>- first placing
the mould on the brick core at one end of the building, and make a mark on the wall at
the bottom of the slipper. This mark indicates the line of the wall rule, and ought to be levelled
from one end to the other end of the building, but the usual way is to follow the courses
of the brick work, though this method is not always reliable, as the brick work often varies in
line. Having made a mark at one end of the building, proceed to the other end, and make
a similar mark. Then strike a chalk line from tho.se marks from end to end of the building.
In striking this line a man must be at each end of the line, and another at the middle, who, when
the line is fully stretched, moves it a little up out of the straight before the line is struck. This
is to allow for the deflection of the line which is usual in a long stretch, also to give a slight

camber to the moulding, which causes it to have
the appearance when finished and viewed from
the street of being perfectly straight. After this
nail the running rules up to this chalk line, taking
care to allow them to sufficiently project at both
ends of the building to carry the mould the required
length for the returns.

The next part of the process is to form a
running screed with neat cement at the top of the
wall rule. This screed must not be more than
I. I. inches wide and \ inch thick, and is cut off
when the moulding is run. When the screed
is firm, proceed to fix the nib-rules. First
place the mould on the wall rule at one end
of the building, and hold it so that the plumb-
bob-line will be in unison with the plumb-line on
the stock of the mould. While in this position
another man draws the nib-rules forward until
close up to the nib of the mould. The rule is
bedded on gauged dots and weighted down with
bricks to keep it in position. The same operation
is done at the other end of the building. Then
stretch a line from end to end to act as a
guide for fixing the intermediate rules, which are required to make up the whole length of the
moulding. The nib-rules are further secured by laying dabs of cement where necessary. The stuff
for roughing out mouldings is compo.sed of the same materials and proportions as used for the wall
floating, gauged stiff, yet of a plastic consistency. Never use soft stuff on a moulding until
completely filled out. In laying stufl" on a moulding of any kind, never allow a smooth surface to
set before the next coat is laid. By the action of the trowel it is impossible to avoid smooth parts,
but where the stuff begins to set the surface should be roughed with a pointed lath or a long nail.
The point of a trowel is generally used for this purpo.se, but this is a mistake, as the sunk line
formed by a trowel is smooth on one side, and is too thin at bottom to afford a strong key for the
ne.xt coat. The nail or lath should be drawn up diagonally, as this way is not so apt to drag the
stuff down or off the moulding as if drawn downwards. After laying on the coarse gauge for two

li.^w' '•'V i, ' iff'

laStone;B7u;k

No. 44.— Pi.rMBiNi; KuNNiNi; Moulds.

Rill I III ng Portland Cement Mouldings. 187

or three hours, according to the size of the moulding, the members of the moulding will begin to
assume form, then cease using the coarse gauge and allow the work to firm for about one hour.
After this use fine stuff to complete the roughing out. This stuff is composed of fine wa.shed river
sand and cement, gauged in the ratio of 5 parts of sand to 2 of cement. Continue with this
fine stuff until the moulding is completely filled out, and let it rest for a couple of hours, or until the
surface sets a little. Then make up some " dryers " with 5 parts of river sand mixed dry with
2 parts of cement, and when thoroughly mi.xed put it into a sack ready for use. Now gauge up as
much soft fine stuff as will cover the whole surface. This .soft fine stuff is gauged in the same ratio
as above, but is made much softer. It is laid very thin all over the moulding without mi.ssing a
spot. The running mould is then gently run over from end to end, pressing steadily, yet lightly.
This done, let every man on the scaffold put a portion of the dryers in his apron, and quickly throw
it on to the wet moulding until it is completely covered, and then clean the rules so that the mould
will have a free passage. If it is a large mould, it is desirable that two men should push it in the
final run, as it requires to be pressed hard to the rules. It may perhaps require one more run
over, but without any stuff being laid, and then the moulding is finished straight and strong,
of uniform texture and colour, and with an eventual solidity that storms and tempests may
lash in vain.

When running mouldings in Portland cement, attention must be paid to all mitres and returns,
so that they may be brought out at the same time as the moulding is being run. Mitres and
returns are worked by hand, so sufficient stuff must be laid on, in order that they may be worked
down with drags and chisels in a similar way to a mason working stone. The mitres are finished
with the same kind of materials as used for the moulding, which will ensure the same colour when
dry, so that no joints will be shown. The next thing to be done is to take the rules down, cut the
running screed off, and clear the weathering of all loose stuff down to the brick work. Then dust
it from end to end with a dry brush and wet it slightly, taking care that no water runs down the
surface of the moulding. After this gauge as much ^-inch shingle and cement — in the ratio of
2 parts of shingle to i of cement — as will cover the entire length of moulding. Lay this rough stuff,
and then rule it fair with a long floating rule, taking care to allow a fall from li inches to 3 inches,
according to the projection of the moulding, as indicated by the dotted line at L on illustration
No. 44. When this stuff is firm, it is laid over with a thin coat of fine stuff, gauged in the ratio of
2 parts of washed sand to i of cement. This weathering surface is finished with the trowel, to get
a close, smooth, and impervious surface, to allow rain to run off freely, and to resist the effects of
rain and snow. Mouldings are sometimes required to be finished with a fine smooth surface.
This is effected by using a finely sifted Portland cement for the finishing coat. All mouldings
of every description should be begun and finished in the same manner as described above. Where
practical, it is advisable to finish the whole of the mouldings in one section or scaffold level before
starting to finish the plain surfaces. Short window heads, if circular or pedimental in form, may
also be cast and planted. It is usual to build a brick or stone core for heavy mouldings over
doors and windows. In this case the moulding must be run and mitred as already described.

Fining. — Fining or finishing plain surfaces on the facade of a building is a criterion of the
plasterer's ability in the manipulation of Portland cement. Uniformity of colour is imperative.
This is obtained by uniformity of gauging, also manipulation of the materials. No joints should
be shown. The smoothness is to be attained by beginning and finishing the given space in one
operation. If the scaffold should interfere with the work being done in this way, it must be
altered, and as man>- men put on to the given space as can conveniently work on it, and thus

1 88 Plastering — Plain and Decorative.

avoid making a joint where it ougiit not to be. For instance, the blocking over the main cornice
should be done first, then the top story between the main cornice and the first string course, and
so on down to the bottom. Well-waslied sharp river sand is required for the fining coat. The
whole of the sand required for the front should be washed and spread out to dry some weeks
before it is wanted, and frequently turned over till it becomes nearly as dry as the cement. When
dry, add to it by measure one-fourth of drj- silver sand. Well mi.K the two together, then proceed
to measure out as much washed sand and cement as will finish the proposed given space in the
proportion of 5 parts of sand to 2 of cement. After mixing these materials, run it through a fine
sieve, and it will be ready for use. The admi.xture of silver sand forms a fine white stone-like
colour, and a close-grained and even-te.xtured surface.

.All splashes and bits of projecting cement must be cleared off the floating surface with
a trowel. The whole surface must then be thoroughly wetted with clean water. On this wetting
depends the ultimate adhesion, also the uniform working and strength of the fining coat.
If the moisture, or blood of the cement, is absorbed b>- the suction of the wall, the cement
will become inert, and the stuff will eventually peel or scale. The water must be thrown on
wholesale until all absorption is stopped for the time being, and the floating will absorb no
more. As a test that the floating is sufficiently saturated, a moist glaze will appear, and
remain for some time. When that glaze begins to clear off, start at once and lay on the fining
stuff, which has been previously gauged and delivered on the scaffold. This stuff must not be
gauged too soft, rather stiffish than otherwise. As much should be gauged at once as will cover
the given wetted space. One plasterer lays the stuff about ^^ inch thick, and another follows with
the traversing rule, working it carefully in all directions until the surface is full and straight. .After
the work begins to stiffen, the surface is gently scoured with a cro.ss-grained hand-float until the
moisture has disappeared from the surface. The next object is to get rid of the hand-float marks,
and transform the surface into a close stone-like face of even texture. This is obtained hy
"patting," that is, gently beating the surface with the full face of the hand-float, which has the
effect of pressing all the jiarticles of the sand into the surface of the work, and effacing all marks of
everj' kind. In patting the surface portions of sand will accumulate on the face of the float. This
must be constantly wiped off with a damp brush, as a thoroughly clean float is necessary for the
proper execution of this class of work. It must be understood that no water is to be thrown on
after the fining stuff is laid. If the floated surface has been uniformly and thoroughly saturated, no
water will be required for scouring, but if a dry spot should appear here or there, then damp the
face of the float with a wet brush, and work the dry spot until it is equal in dampness with the
other work. Large spaces should be commenced early in the morning, to give sufficient time to
keep the work going, as every space should be finished the same day as begun.

S.\XI> FOR Fixing. — In order to obtain a smooth, even-grained, and uniform surface, the sand
for the fining should be well washed through a fine sieve. The thinner the coat of fining the finer
the sand should be, so as to allow sufficient space between the wall surface and the finished surface
for the grains of sand. It is obvious that if the sand grains are equal in size to the thickness of
the fining, there is little possibility of con.solidating and forming a fair surface by "patting" ; but
if the sand grains are smaller than the thickness of the fining, an allowance is obtained for patting
the surface, so as to get it compact and uniform. Although the sand is fine, it should not be flat
or round, but sharp and angular, otherwise it loses its powers of keying and bonding, which are so
necessary in this as in all plaster and concrete work. Portland cement facades are simply a form
of fine concrete, and fining may be described as concrete in its smallest degree or scale. The

Filling Port la lid Cement Faqadcs. 189

fineness or gauge of the sieve for washing the sand must be regulated according to the required
degree of fineness or size of the sand.

Trowelled Portland Cement.— It is often required that Portland cement should have a
fine smooth surface. This is obtained by using a finer material for the fining coat, and then
scouring, trowelling, and brushing the surface in a similar way as described for working Parian
cement. The materials consist of Portland cement, sand, and lime, in the proportion of 2 parts
of cement and i of sand, and i part of fine lime putty, and the whole thoroughly incorporated
together. B}- using silver sand a white lustrous surface is obtained. Portland cement that works
short under the trowel may be corrected b_\- adding i part of old lime putty to each 5 parts of
Portland cement. The lime renders the stuff fat, plastic, and easy to work, without decreasing its
impermeability. This " limed cement " may be safely used where an extra fine smooth finish is
desirable.

Plaster Screed Proce.sS. — A novel method for executing Portland cement fronts is by the
use of plaster or " skeleton screeds." This method may be employed with advantage during
excessively hot weather, or where there is an unusually strong suction. It enables the work to be
done in one operation. B\- this continuous process the fining coat can be laid as soon as the
floating coat is " green " (that is, when a coat is set or firm, but not dry). This is an important
factor in the perfect cohesion of the two coats, and free natural working of the material and
uniformity of texture and colour, with the best results at the least cost. Skeleton screeds are simply
temporary screeds for plumbing, levelling, floating, and running mouldings. They are formed with
plaster, so that they can be used straight away, instead of ha\ing to wait two or three hours to set
(as is sometimes the case with Portland cement).

The plaster being cut out when the screeds are done with, and the spaces filled up with the
same kind of materials as used for the floating, allows the work to dry uniformly. They should be
narrow, not more than li inches wide for floating and 2 inches for running screeds, and are best made
as described for " pressed screeds." After the plaster is pressed under the edge of the rule, the
superfluous stuff at each side of the rule should be cut square by drawing a trowel along each side
of the rule, cutting the plaster right down to the brick.

A square edge makes a better joint, and the screed is more easily cut off when done with.
The upper edge of the running screeds must be cut in a line w-ith the bottom member of the
moulding cornice. In some instances it may be necessary to make the running mould so that it
will form a bearing about i inch deep on the wall surface. All mouldings are run first, and then
the running screeds (unless required for floating) are cut off The floating is then proceeded with,
but only as much should be laid as can be finished the same or following day, and in one operation.
As soon as one bay of the section is floated, the skeleton screeds are cut out and the space made
good, so that the whole surface can be finished at the same time. With the exception of the
screeds, and running the mouldings first, all the other work is done as described for the permanent
screed process.

Coloured Fa(;ades. — Portland cement fronts may be further decorated by the use of various
coloured parts. \'arious colours can be imparted to the finished surface by mixing the metallic
oxides with the cement. The admixture of silver sand to cement )-ields a semblance to fine white
stone. Crushed spar, glass, granite, &c., used as aggregates for the final coat, impart a lustrous
appearance to the finished surface. The linear ornamentation and the various tinted strata of
sgrafiitto may be artistically employed for relieving plain surfaces in Portland cement fa9ades.
Pleasing effects may be obtained by using natural coloured sands of different tints for gauging

I90 F/asieriiig — P/(7iii and Decorative.

with cement for llic finnl coat. Some years a^^o I saw a house front at Duns, X.B., executed by
W. Smith, treated in tlie followini^ manner. The fac^ade was set out with Hues to represent ashlar
stone work. The stones were varied in colour alternately b\- usini; a rich yellow pit sand from
Gilmcrton for some, and a gre)- river sand for others. Red sand and brick-dust is used for a
similar purpose, also for colouring' cast concrete. Bullocks' blood mixed with cement has been
used to obtain a resemblance to red brick. Earth)- stains are not so durable as mineral oxides,
they also tend to weaken the cement, whereas mineral oxides have a reverse tendency. Manganese,
or manjjanitc, is also of a suitable nature. The colouring matters mentioned for sgrafifitto may also
be used for faqades, mouldings, and castings. For a Caen stone colour, 4 parts by weight of yellow
oxide, \ part of red oxide, and 36 parts of cement ; for dark red colour, 10 parts of red oxide to 36
parts of cement ; and for a bufif stone, 8 parts of yellow oxide, i part of red oxide, to 36 parts of
cement. These proportions vary according to the strength and qualit>' of the oxides. Bright
effects are obtained by using crushed white or bright-coloured glass as a substitute for sand. The
colour of cast work, if mixed with the plastic materials when casting, will last as long as the cast.
Coloured cement or stucco will last as long as the work, whereas if thev were coloured on the
surface only, the colour would soon wear off.

PrkskrxiNG Pl.-vstekeI) FA(,'.\DKS. — To obtain durable work and guard against defects in
the form of laminations, water-cracks, discolorations, and vegetable or other growths on cement
facades, the materials must be carefullj- selected and manipulated. The work should also be painted
at inter\'als. This maj- be done with oil-paint, distemper, cement-wash, or with some of the other
compounds given in the " recipes." The primar)- cause of the premature decay which sometimes
takes place in stuccos and cements when used externally on facades or walls is the presence of
muddy earth and decayed animal and vegetable matter in the sand used with the lime and cement.
To this may be added frequent impurities in the limes and cements themselves, particularly of
argillaceous matter in the former, and sometimes to the too great proportions of sand to lime or
cement. These things might, however, remain quiescent for a long time if the work were well
protected from access of moisture, which is the great exciting cause. The jjaint, distem]3er, or
cement-wash on the surface is gcneralh- sufficient to prevent the rain which may beat against a
vertical face from penetrating, especially if the work has been well hand-floated and trowelled, to
make it close and compact ; but the evil arises from exposure above, and from the numberless
horizontal unfloated surfaces which are constantly presented. These receive and collect the water,
and convey in streams over the vertical surfaces what is not immediately absorbed, and the work
thus becoming saturated, frost seizes and bursts it, or warmth calls the vegetative powers of the
impurities in it into action, and the whole is covered with a green sward. Let the sand of which a
plaster composition is to be formed, whether with lime or cement, be washed iinlil it no longer
discolours clean water, and be well com])ounded with cementitious matter free from the impurities
with which it is so frequently charged ; let the work be well hand-floated and trowelled, particularly
on the backs or upper horizontal surfaces of projections, and protected above by projecting eaves, or
otherwise, and with common care and attention to paint, distemper, or cement-wash at intervals,
it will last as long as anjthing of the kind can be expected, or is found to last anywhere. Painting
the surface with oil-jmint, distemjjer, or cement-wash at intervals also makes the work look bright
and cheerful.

Fixing Points for MktaL AI'PLIANCE.s.— In facades finished with Portland or other
hydraulic cement, care must be exercised to provide wood plugs, or the brick joints marked on the
surface, as fixing points for metal signs, pipes, brackets, water pipes, rain-water heads, or similar

Pediineiits. '9'

appliances which are frequently fixed on exteriors. The positions and size of these metal
appliances should be ascertained, and the necessary plugs inserted in the brick work, before the
fining is commenced. Nothing looks so unsightly or distressing to the eye as patches on a newly
plastered surface. Fixing points or orifices for fixing metal weathercocks, vanes, or finials or similar
terminations to turrets, spires, or apexes, should also be formed before the fining is commenced.
Excellent examples of rain-water heads, vanes, and finials, designed by some of our leading
architects, and manufactured by Mr T. Elsley, are shown in the advertisement pages. The.se well-
designed e.xamples will serve to show their use, application, and mode of fi.xing. By adopting this
method of first forming fixing points and then fining the surface, the metal appliances can be readily
fixed and without fear of injuring the wall surface. It also enables the metal appliances to be
freely unfixed for cleaning or repairing purposes. Small or light rain-water heads can be securely
fixed by inserting nails into the joints of the brick work. In this case the positions of the joints
should be indicated on the fining coat, by means of chalk or pencil marks, as guides for fi.xing.
This gives a secure fixing, and avoids seeking for the joints, and saves unnecessary breakage of the
finished surface.

Examples of some of the principal parts of facades are now given to further assist the plasterer
in the working of Portland cement facades. They will also be of service for interior works in lime
and white cement plastering, and also for fibrous plaster work.

Pedi.MENTS. — Pediment — in French Fronton ; from the Latin Frons, the forehead — is the
triangular ornament that sometimes crowns the front of a building, or of a door, window, or niche.
Pediments are, however, sometimes in the form of the segment of a circle, when applied to doors and
windows. A pediment consists of a horizontal cornice, supporting or enclosing a triangular or
curvilineal space, either plaTa or enriched, called the tympanum or tympan, which is covered either
with two portions of straight inclined cornice (generally termed a pitched pediment), or with one
curvilineal cornice (sometimes termed a compass pediment), following the direction of its upper out-
line. Tympani are often decorated with shields, male and female figures, foliage, and flowers.
Besides the triangular and circular pediments, they are sometimes composed of both these forms,
some of an undulating figure, some semi-he.xagonal, some with the inclined cornice and tympan
open in the middle to receive a bust or other enrichment, and others where the aperture is left
void, and the two ends of the inclined cornice are finished with a couple of \olutes or with
returned ends.

The face of the tympanum is always placed on a line perpendicular with the frieze. The two
uppermost members of the cornice are always omitted in the horizontal one of a pediment, that
part of the profile being directed upwards to finish the inclined cornices. When the cornices are
ornamented with modillions, dentils, &c., the ornaments of the inclined cornices should be
perpendicular over those of the horizontal cornice, and their sides be perpendicular to the horizon.

The formation of large pediments on facades in Portland cement requires accurate .setting out
to avoid errors and subsequent alterations. Two running moulds, one for the inclined or raking
cornice, and one for the horizontal cornice, are required. The cornices are run on a wall running
rule and a nib running rule, and after the mitres and returns are " put in," the weathering or flat
upper surface is laid and finished fair and smooth. For extra large pediments the inclined
moulding is run in two sections, using the soflit of the moulding as a screed. This part is finished
by hand after the moulding is run.

For small pediments over windows and doors the horizontal cornice is run first, and then the
inclined cornices are formed by fixing a plaster mould on the horizontal cornice and against the

192

IVnsfcriti^ — P/niii mid Ik'corative.

wall. This mould is then filled in with fine concrete, and as soon as it is set the mould is
withdrawn and the mouldin^'s fined off. The tymjjani are then fined ofif, or filled in with an
enrichment, as the case maj- be.

The plaster mould for the inclined cornices can be so constructed that the two inclined
cornices, with the two returns and the a[)e.\ mitre, are all formed in one operation. The upper or
weathering part is left open to allf)w the fine concrete to be run in. The casting mould is best
formed with a reverse running mould. .\ casting mould constructed with fibrous plaster maj-
also be advantageously used for forming the triangular or circular parts of pediments. Heing of
a more jielding nature than solid plaster, the fibrous mould can be " sjjrung " and taken off more
frecl}-, and with less risk of its breaking and also damaging the work. Whole pediments may
be formed in one operation by the use of plaster moulds fixed /// situ,-,\x\<\ then filled in with fine
concrete and finished off hy hand. Stone, brick, or rough concrete courses should be built in the
walls to act as brackets for the cornices. In the absence of cores or brackets, chases must be cut
in the wall, to allow the fine concrete to bond into the w-all, to form a support for the cornices.
The method of making a reverse casting mould for pediments is demonstrated in Chapter XIII.

Pitch of Pediment.s. — There are three different rules or proportions for determining the
pitch of pediment.s. The.se are two-ninths, one-fifth, or one-fourth of the whole extent, the first of
which is shown in the annexed illustration (\o. 45), which is self-explanatory.

No. 45. — Prrcn ok Pediments.

K.\KINr. Mou 1.1)1 N(;s. — The chief difficulty in the working of pediments is to set out the
])rofile of the raking cornice so that it will intersect or mitre accurately w'ith the horizontal part,
and in the case of an open pediment, where the raking or pitched cornice is returned at the
ui^pcr end, that the fillet or other vertical members of the cornice will be perpendicular The
method of setting out these mouldings are as follows. The method of setting out the raking profile
of various members is elucidated in the annexed illustration (Xo. 46). In all the figures, A is the
profile of the horizontal member, I) the raking profile of the inclined moulding, and C the raking
profile of the returned end of an open pediment.

To Dksckiisi-: the Raking Pkoiile.s ok a Cv.ma-kect.v. — Take a, l-'ig. i, as the given
c)-ma-recta of the horizontal cornice, the bed of which extends from c to /', and from b to g^
and the profile or horizontal section from c to g. To describe the raking cyma-recta, first
divide this profile into four equal parts as d, e, f, and from these points draw the horizontal lines
if, k e, and q d ; then from the same points {d, e, /) draw parallel raking lines, as from /to
1, ^ to 2, and d to 3, according to the desired pitch of pediment. Again, from the points d, e,f, draw
the perpendicular lines d k, e /, and /";//. This done, draw in an\- i)art, as n 0, at H, a right line at
right angles to the raking lines ; then make the horizontal lines q iv, r u, and s t, equal in length
to the lines if. k i\ and q d in A ; and then on the lower line of the fillet as / 0, set out the

Raking Mouldings.

193

points for the lines w, /, k, making them equidistant to the lines in, /, k in A, and from these
points draw lines parallel to n till they cut the raking lines in the points q, r, s, and then through
the points/, </, r, trace the upper curve of the cyma-recta, and through the points ;-, s, n, trace the
lower curve, thus forming the required raking cyma-recta. The curves may also be described
with a compass by finding the centres to describe the arc of a circle to pass through the three
points p, q, r, and r, s, n.

To Describe the Profile of a Returned Cornice. — The following method can be

No. 46.— Raking Mouldings.

used for describing the profile of the returned cyma-recta in the inclined cornice in an open
pediment ; also to return a raking moulding to a level moulding at the top. First draw a
horizontal line from the fillet as at p to o, at C, Fig. I on illustration No. 46, making the length
equal to the projection of the corresponding line / <? in B (which is also equal to the line b g'm
a), and then divide the line « in four equal parts, and from these points («', u, t) draw horizontal
lines, keeping them equal in length to the corresponding lines q ti-, /- n, and s t \x\ B. Next
on the line / set out the points for the lines /, «, ic, making them equidistant to the lines w. /. k.

"94

Plastering — Plain ami Decorative.

in B, and then from these points draw lines parallel to n o till they cut the raking lines in the
points q, r, s. Having obtained these points, trace the curve from / to « through the points </, ;•, s,
which gives the profile of the returned member. The curve can also be described from centres,
one of which is shown. The same methods are employed for describing the profiles of the
cyma-revcrsa, the cavctto, and the ovolo, as shown at Kigs. 2, 3, and 4 respectively on illustration
No. 46.

When running the raking and other mouldings on a pediment, the running moulds are cut and
horsed in the usual way as shown at D (illustration No. 46), but when running them for fixing
purjjoses or for model-making, the running moulds should be horsed so that the moulding can be
run on a running board ; also that the moulding will ha\c a bed for fixing purposes. The method
of setting out the running mould for this purpose is effected by extending the back bed of the
moulding, then cutting the running mould to have two bearings as shown by the section of the
mould plate at E. The foregoing methods can be emplo)-ed for circular raking mouldings, also for
reverse running moulds for fibrous plaster, and for concrete work.

R.VKING MoDlLLlONS. — The method of setting out an Ionic modillion for a horizontal cornice,
and the raking modillion for a jjcdiment or an inclined cornice, is elucidated on illustration No. 47.

No. 47.— Side and Kkont Elevation ok Io.nic Modillion, with Raking Modillion.

Fig. I shows side and front elevations, with sections of an Ionic modillion, and a part of the soffit
of the corona for a horizontal cornice. The method of setting out the modillion is indicated by the
figured proportions, and the dotted lines, and centres; the latter being used for drawing the curved
section. Fig. 2 shows the method of setting out the raking body and moulding of the modillion
for the inclined cornice of a pediment. The raking moulding is set out by the aid of compasses, as
already described and indicated by the dotted lines and centres. The above method may be
employed for setting out other forms of raking modillions.

To Construct a Doric Portico. — It will greatly simplify the working, and give the work-
man, especially in his initial efforts, a better grasp of the method of construction, if he first draws
the work to scale. The annexed illustration (No. 48) will explain the method of setting out and
drawing the main parts. To .set out a Doric portico or frontispiece, first draw the base line A U,
and erect the perpendicular line I H, and on this mark the height of the first or uppermost member
of the horizontal cornice as at H, according to the number of diameters in the order. Divide the
entablature into its three parts, viz., architrave (composed of two fasciae, with a fillet also termed
"tenia"), the frieze, and the cornice. A trigl)-ph, I', is always placed over the columns, and its breadth

Plastering Doric Porticos.

195

is equal to half the diameter of column at its base. The distance between the triglyphs is generally
equal to the height of the frieze, therefore square. In some examples there are various numbers of
triglyphs placed between those over the columns according to the length of cornice, but in this
example there are three. The intercolumniation for the three triglyphs, according to the scale of
this order, is five diameters, that is, the distance from the central line C E to the central line D F. The
intercolumniation being found, take half thereof between the compass, and setting one foot in the
point I, make a point at each side upon the line A B at C and D, and then erect the perpendicular
lines C D and E F for the central lines of
the columns. The triglyphs are spaced
out on the base line A B as follows : —
Take fifteen minutes, the half breadth
of one of the triglyphs between the com-
pass, and make a mark on both sides of
the point C as a, b, and on both sides of
the point I, as e,f, and on the point D
make two points as c, d. Now take forty-
five minutes, the height of the frieze
(which is the width of the metopes)
between the compass, and place one
foot on the point f, and make a point
as at h, and then from the point e make
a point as at /, from g to It, and also
from / to k, which is the width of a
trigl)-ph. It will be seen that this method
gives the width and positions of the
other triglyphs as a^,/^, and c d. These
widths and positions are then transferred
from the base line to the frieze, working
from the centre lines of the portico and
columns. The width and positions of the
mutules are regulated b)- the triglyphs.
The height of the members of the cornice
are set on the centre line of the column
from the point /J The two upper lines
that make the square of the cyma-recta
are omitted because of the circular cornice
mitring to the level returned cornice.
The projections are taken from the centre

line of the column. To find the pitch of the pediment, set one foot on the point H, extend the
other to G, and then turn this foot to the centre line I H, and make the intersecting point O,
which is the centre for the circular pediment, also termed a compass pediment. The same rule
is also used to find the centre for a raking or angular pediment, as shown by the dotted line R to G.
The space between the triglyphs are called metopes, and are generally filled in with some
ornament. In some antique examples the metopes are alternately enriched with ox-skulls and
with pateras, but thej- ma\- be filled in with any other ornament of appropriate form. The method

No. 48. — Setting Out ..\nd Forming a Doric Portico.

196

Plastering — Plain and Decorative.

\:::::

Cap

■ Tr^/yj>A

.^/Ct^t-fie.

J&7.

of drawing the triglyph, guttii;, and panel with jiatera is further elucidated by the annexed sketch
(No. 49), which shows the elevation and section, with the parts figured, and is self-explanatory.
The gutt.-c or drops in this example are pyramidal in form, but in many examples they are conical,
being cones, or parts of cones. The soffit of the corona is often enriched. These enrichments
should be sunk up, and never drop lower than the line of the soffit. Three forms of mutules,
a "centre" and "rights" and "lefts" (as shown in illustration No. 48), are required for the
circular cornice, so that their sides will be perpendicular and rake with the sides of the mutules
on the horizontal cornice. The " rights " and " lefts " require to be specially made. The centre
one may be obtained from the casting mould of the mutules for the horizontal cornice by bending
it to fit the curve of the circular cornice. The front and sides of the mutules are sometimes
enriched by a series of dog-tooth sinkings, as shown by the centre mutules and two external ones.

The method of forming a portico in Portland cement is as follows : — First form vertical screeds
on the walls close to the outer sides of the columns, taking care that they extend from the plinth
of the column to a little above the level of the apex of the pediment, then fill in the plain
intermediate spaces and rule them off, using the vertical screeds for bearings. On this surface set
out the full size of the main parts of the work to be done. All measurements should be taken from

the centre of the portico. This centre line is
obtained from the centres of the columns, as
described for the setting out. If the work
is large, or the pediment to be run, the circular
cornice or angular cornice, as the case may be,
should be run first, so as to save long mitres,
also to prevent stuff falling on the horizontal
cornice, which .sometimes happens if the latter
is run first. For small work, the horizontal
cornice and the architrave are run first. This is
done from a parallel running rule fixed on the
frieze. If the work is large, fi.x two running
rules on the frieze, one for the cornice and one
for the architrave. In both cases a running rule
is required for a bearing for the nibs of each running mould, one fi.xed on the weathering at the
top of the cornice, and one on the soffit of the architrave. After the mitres are " put in," the
tjmpanurn is fined, and then the mutules and triglyph are fixed. The upper surface of the pedi-
ment and the portico is fined as soon as the mould of the cast part is taken off. The columns
and the soffit of the architrave are ne.xt formed, the former being carried out in a similar way as
described for diminished columns.

To Construct .\n Ionic Nichic. — The subjoined illustration (No. 50) shows the elevation
of a niche in the Ionic order with columns on pedestals. The height of the niche is 2 diameters
and ,, inch, and to the top of the keystone 3 diameters. The height of the impost, breadth of the
architrave, and the size of the keystone are explained by the circles. An inverted circular pediment
is here given, but an angular or pitched pediment, as shown by the dotted lines (which extend from
the extreme angles to the apex of the pediment), may be used instead of the circular pediment if
required. The dotted lines on the bases and columns indicate the centres from which the niche
is set out.

The method of construction in Portland cement is as follows : — First plumb the walls, and

3 Ts^iy\\\.

^^mffintifn .

(rn/tirJ.

No. 49.— .Settino Out Triolyphs.

aAr<r

Plastering Ionic Niches.

197

form vertical screeds near the outer sides of the cokimns. The screeds must be plumb, and extend
from the plinth of the pedestal to a little above the level of the apex of the pediment, then form
vertical screeds on the piers, also at the sides of the panel space between the pedestals, taking
care that they are plumb, also parallel in projection with the outer screeds. This done, fill in all the
intermediate plain spaces, and rule them off from the vertical screeds. The pediment is next
formed, this being done as described for pediments. Here the advantage of casting the circular
cornice in situ will be seen. If this had to be run, the core of the horizontal cornice would require
to be cut awa)- to allow the running mould to pass to the external angles, which otherwise would
entail extra long mitres, and being circular, they would be
more difficult to form. A long mitre would also occur at
one side of the apex mitre, as only one side of the circular
cornice could be run the full length. In this example
the frieze is swelled. This may be run with a template
after the cornice and the architrave is run. For this
method, about i inch deep of the swell at top and bottom
are run with the horizontal cornice and the architra\e.
An allowance must be made for this when cutting and
"horsing" the respective running moulds.

Another way is to cut two templates to the curve
of the swell, and fix them temporarily on the surface of
the frieze, each about 6 inches from the mitres. The
spaces between and beyond the templates are then filled
in and ruled off until flush with the templates. When
the stuff is firm, the templates are extracted, and the
holes formed by the templates are filled in, thus leaving
a fair and true curved surface for the fining coat. When
a swelled frieze is cored out in brick work, form screeds
at the top and bottom of the frieze, and on these fi.x
running rules for running the horizontal cornice and
architrave (as already described , and then run the
swelled frieze. Another wa\- to form the frieze is to make
narrow vertical screeds at each end, with a wooden tem-
plate cut to the curve of the frieze, and then fill in the
intermediate space and ends, and rule the surface fair with
the screeds, and when the stuff is set proceed with the
fining. The modillions are next fi.xed. Three different

forms of modillions are required for an inverted circular pediment — one for the centre, one for
the " rights," and one for the " lefts," on each side of the centre one. These require to be
speciall)- made, so that they \\\\\ fit the cur\c of the cornice and their sides be perpendicular.
It ma_\- here be remarked that the construction of the three different models of the modillions
entails a considerable amount of labour. This, with the addition of making a casting mould
for each model, will double the labour required for making a model of a modillion for the
horizontal cornice. Under these circumstances, it would be a simple matter of justice to the
client and the plasterer, if all quantity sur\e)-ors would make a note of ever}- item, however
small, which requires to be speciall_\- made, so that the\- can be valued and allowed for in the

Xo. 50.— SEili.Ni. Ol 1 AND FOKMINC,
lO.NIC XlCHE.

Dido

198 Plastcri)ig — Plain ami Decorative.

plasterer s cstimiitc. After this slight digression, the method of construction will now be resumed.

The circular crown and body surface of the niche is next formed, as described and demonstrated by

illustration No. 43, in Chapter \T. The archivolt moulding is next run, and then the crown of the

niche finished. The circular impost moulding is ne.xt run. This may bs run from a running rule

bent to the circle, taking care to keep it level. The columns are ne.xt formed, this being done as

described for diminished columns. The keystone is then fi.xed, and the straight lengths of the

impost mouldings, which form caps to the piers, are then fixed. These are run down, and then

cut to the required lengths and mitres, taking care to cut the butt ends to fit the curve of the

column.s. The impost mouldings are fixed before the columns are fined, as it is easier, and makes

cleaner work, to fine the columns to the members of the cornice than it is to make good the

members of the cornice to the column after it is fined. The pedestals and the panels arc then

formed, as described hereafter. It will be understood that all the plain surfaces are finished as the

work proceeds.

To CoxsTRUCT .\ l'El)EST.\L. — The annexed illustration (No. 51) is an example of a

pedestal. A pedestal has three parts — the base, the die, and the cornice or surbase, commonly

called a "cap." The height of a pedestal properlj' proportioned is from

? one-third to three-tenths the height of the column ; the die is nearly of

the same figure, being a cube, or made as high as the width of the

plinth belonging to the column it supports. The whole height of the

pedestal may be divided into nine parts, one of which must be given to

the cornice, two to the base, and the remaining parts to the die. The

projection of the cornice should be equal to its height. With regard

to the method of constructing in Portland cement on a brick foundation,

the die is first floated, taking care that the screeds are jilumb, and that

the sides are square with each other. The cornice is run from running

rules fixed on the die and nib rules on the upper surface. The base

may be run with a twin-slippered mould from a running rule fixed on

„ „ the die, or it may be run from a rule fixed from the plinth member

No. 51.— Plain Pepestai.. ^ '

formed in the same manner as described for skirting. The latter way
allows the full length of the moulding to be run, thus avoiding long mitres. When constructing
a model of a pilaster in plaster, the cornice and base mouldings may be run down, cut to the
lengths and mitres, and then jjlantcd on the die. It will be understood that the die should be
made sufficiently high to include the heights of the cornice and ba.se, so as to afibrd a ground
for running, or fi.xing the mouldings thereon. When constructing pedestals in fibrous plaster,
a casting mould made by the reverse moulding process should be used.

Compound Opkn Pediment. — The accompanying illustration rXo. 52) elucidates the method
of setting out and constructing a compound open pediment. This shows nearly one-half or side of
the pediment. The intersection of the circle line with the horizontal line at I — when continued —
gives the centre of the complete pediment. To .set out half of the compound circular cornice,
divide the whole length of the half pediment into four parts and return the cornice at three of those
parts as shown at .\ B. The centres C, C, from which the reversed curves of the cornice are struck
are obtained from the oblong as indicated by the dotted lines D c, B C. The dotted diagonal line
from C to C gives the intersections of the reversed curves. This form of pediment is best made by
making a plaster model, then moulding and casting as many as are required. To make the model
run a length of each curve, then joint and fi.x them together, and then form the scroll end by hand

I'luOi, af ^n, .

Pediments, Coynices, and Qnoins.

199

and the aid of a template. The patera is modelled, cast, and then planted. This done, run a
straight piece of the top member — the cyma-recta — and cut it to the desired lengths and mitres, to
form the straight parts of the cornice which intersect with curved parts at the ends, and also to
form the returned mitres. The returned member above the .scroll end can be worked by hand.
The other side of the pediment is of course made in the same way. The horizontal cornice II is
generall}' run in situ and the compound circular parts planted on it ; but for small work the whole
pediment can be cast in one piece and then
planted. The horizontal cornice can also be
run ill situ and the circular parts cast /;/ situ
with the aid of a plaster mould as already
described.

Block Cornices and Quoins. — Cornices
having blocks or trusses, especially of the classical
orders, are usually set out from a scale or module,
as shown by the figures on illustration No. 54.
The projections of the members are taken from
the perpendicular line. As regards the work-
ing, if the cornice is large, a screed is formed on
the bed of the blocks, and the upper and lower
portions run from a parallel running rule fixed
on this screed. The annexed illustration (No.
S3) shows the front and side elevations of a

modillion or console 'commonly called a block), from the Temple of Jupiter Stator, Vatican,
Rome. This form of modillion is often used for exterior work. When fi.xing blocks, or
similar work of a hea\'\' nature, care must be taken to obtain a permanent support b\' driving
strong nails into the vertical part of the bed, or by fixing pieces of slate on edge and bedding
them with cement. A hole sufficiently large to receive the nail and a coating of cement
must be made in the backs of the blocks while they are being cast. The blocks should

No. 52. — Setting Out .\nd Forming Comi-ound Open
Pediment.

No. 53. — FuoNT AM) SiiiE Elevation oi' Modillion for Exterior Work.

be fi.xed with neat cement, gauged with lime putty in the proportion of 3 parts of cement to i of
lime. Heav\- blocks are temporarilj' supported by wood struts, also by gauged plaster. These are
removed when the cement is set.

Quoins must be accurately set out according to their size, from the bottom member of
the cornice down to the base. The heights of quoins are usually equal to half the depth
of the cornice, and are in proportion to one another for length as 2 to 3, and the splaxed

200

Plastering — Plain crinl Decorative.

edges arc cut off one-eighth of their height. If the quoins have a large projection or a small
moulding on their edges, they may be cast and then planted in position. In some instances
a brick core is built for the quoins ; it is then necessary to run them /// si/it. For ordinary
sized work the whole surface of the quoins from top to bottom is roughed out to the desired thick-
ness after the walls are floated. This is best done by nailing thickness rules to the desired outline
on the walls. The space is then filled in with gauged cement similar to that used for floating the
walls. When the stuff is firm but not set the sinkings are cut out, allowing a sufficient depth for
the running mould and a thickness of fine stuff. Running rules are then fixed on this surface, and
then the splayed, square, or moulded sunk joints (as the case may be) are run as already de.scribcd.
The sinkings (especially if splayed) may also be fined by hand, while finishing the surface of the
quoins. In this case the sinkings must be more carefully cut out, and the depth and form may be
better determined by the aid of a template. A rule with a V-shaped edge, or a feather-edged rule
and a V-shaped hand-float, are useful tools for this kind of work. The surface of quoins is usually
vcrmiculatcd. This is done with a knife before the .stuff is set. Considerable variety of form and

effect can be imparted to vermiculation.
A plain margin is left on the edges of
the quoin, and from this a series of
irregular or zigzag bands (somewhat
smaller than the outside margin) is
formed across, anil the inner jjortions
are sunk, leaving a rough or matted
surface. In order to obtain a surface
sufficiently plastic to be easily cut, and
also a uniform depth for sinking the
intermediate spaces, it is best to run a
surface margin with the plain or moulded
sinking between each quoin. It will be
seen that this leaves a sunk space on each
quoin. This allows one or more quoins
to be filled in, and vermiculated as re-
quired, according to the time required
for vermiculating before the stuff is set. When roughing out the thickness of the quoins, an
allowance must be made for the depth of the margin on the edges of the quoins, which represents
the finished surface. Another form of vermiculation consists of leaving the whole quoin, with the
exception of a margin on the edges, with a strong jagged surface. Quoins are also sometimes left
with a matted surface. The jagged surface is done with a knife, and the matted w itli a rough-faced
or matted hand-float ; also by laying a piece of thick, rough, and open canvas over the surface, and
beating it with a hand-float. A sheet of zinc, with a series of punctures leaving their edges or points
projecting, may also be used in a similar way. Vermiculation in some cases projects beyond the
outer margin of the block. In this case a somewhat regular rock-like surface is left. This is best
done by hand, and when cut the surface may be further roughened by stabbing it with a
coarse and stiff brush. Illustration No. 54 elucidates the various parts. .\ shows the end or
small quoin, left plain ; 1! is the large or face of quoin, vermiculated. The dotted lines at C,
dividing the square into four smaller squares, show a method of forming a " cyma-recta " composed
of two equal quadrants (or quarters of a circle), which are described from the points D, D.

No. 54.— Setting Out anm) Formi.nc. Block Cornice and
Quoins.

Gafeivays and Rustications.

20 1

Vermiculated work is often used on keystones and basements. Rustication is also another form
of finishing stone surfaces, the face being worked to produce a rough or crispy surface.

To Set Out Quoins. — The method of setting out the quoins of a building is elucidated in
the annexed illustration (\o. 55). First draw the base line a c, then erect a perpendicular line as
a h, then erect the line as g h, and the line ef, each line being set out according to the required size
of quoin. The line a b represents the external angle of the house, the line^/s the internal line of
quoins, and ^/the external. Suppose a b to be the height on which the quoins are to be disposed,
and on the supposition that there are to be twelve quoins ; divide a b into twelve equal parts, and
through the points thus obtained draw lines parallel X.o a c, \ d, and so on to the top.

Gateways and Rustic.\tion. — Rustication is capable of expressing ornateness. It forms a
bold finish, prevents baldness and insipidity, produces richness of surface,
and what in architectural language is termed color. The joints of the
stones may either be square or chamfered ; the square one should not
be wider than one-eighth of the height of the stone, nor narrower than
one-tenth, and their depth nearly equal to their width. Chamfered
joints should form a rectangle, and the width of the whole joint may
be from one-fourth to one-third of the height of the flat surface of the
stone. The annexed illustration (No. 56)* is given to show the method
of working rusticated work and " vermiculated " surfaces. Fig. i is

Tl '^

the plan and elevation of a rustic gate in the Tuscan style. After

the walls are scrceded, the pediment, entablature, archivolt and impost

mouldings, and the columns are executed as already described. The

shell in the " tj^mpanum " and the ox-skull, and the swag of leaves

on the frieze, may be modelled in situ. Work of this nature, when

modelled iti situ, is more effective and economical than cast work, and

being worked on the surface while green, it forms one body, and is

generally stronger than cast work which is planted. The cone vases

should be cast. The rustic blocks on the columns are formed by fixing

bands on the columns and then filling in the spaces, and ruling flush

with the bands. The bands are made of plaster and to the desired

projection of block beyond the line of column. The surface for

the rustication must be floated out to the required depth of the sunk

joints. The position of the various stones with their joints are then

set out, and the joints cut out and fined, or run as already desreibed. The

vermiculation on the swelled frieze of the entablature, the blocks on

the columns, and the wall surface is done before the cement is set hard. Fig. 2 is the plan and

elevation of a gate or entrance in the Doric style. This is executed in the same wa\- as described

for Fig. I. The blocks on the columns are square on plan.

Columns and Arches. — The method of placing columns over columns and arches over
arches, and the setting out and construction of same, is elucidated on the annexed illustration (Xo.
57). This shows the Corinthian order over the Ionic on a rustic ba.sement. The upright scale
shows the height in diameters of the orders and their principal parts. When two or more orders
are employed and placed upon each other in a building, the laws of solidity require that the
strongest should be placed lowermost ; therefore the Tuscan is to support the Doric ; the Doric the

* From designs by Sir \V. Chambers.

No. 55.— Setting Out
Quoins.

202

P/ns ferine — Plain <nu/ Dcconrfivc

Ionic, the Composite, or Corinthian ; and the Composite the Corinthian. 15)- this arrangement the
plainest or most massive are placed lowest, and the most enriched highest. The first or lowermost
order gives the size of the diameter to the order immediately over it, as shown by the Corinthian
over the Ionic on the illustration. It will be seen that the diameter at the base of the Corinthian
column is equal to the diminished ]jart of the Ionic column. The diameter of the upper order is

No. 56.— I'l.AN ANri Elevation 01 (iATEWAv, wnii Kcstications.

therefore regulated b>- the diminish of the lower order. The diameter of the upjjer order may also
be^obtained by dividing si.x diameters of the lower order into seven parts, one-seventh of which will
be the diameter required for the upper order. In this and all other cla.ssical compositions, the intcr-
columniation is decided by the diameter ; as also by the divisions of the metopes and triglyphs of
the Doric order, and the modillions of the other orders. Their proportions in respect to the

Columns and Arches.

203

No. 57.— Columns and Arches. The Corinthian
Order over the Ionic on a Rustic Basement.

diameter are as follows :— The Doric from centre to
centre of the triglyphs is i^ the diameter, the tri-
glyphs I, and the metopes \. The Ionic from centre
to centre of the modillions is \ the diameter, the
modillion \ and the interval % of it. The Corinthian
from centre to centre of the modillions is jV (twelve
times in seven diameters) of the diameter, the
modillion \, and the interval ^,. The Composite
from centre to centre of the modillions is J the diameter,
the modillion ,V, and the interval %. In placing columns
above each other the axis of all the columns must
correspond as indicated by the dotted lines. This
example shows the intercolumniations with three-
quarter columns. The distances betwixt centre and
centre of the columns are figured. As a general
rule the pedestals should not be less than \ of the
combined height of the column and entablature ;
but here it is necessary to make it less, otherwise
the breasts of the windows would be too high, if the
columns were of a large diameter.

With regard to arches over arches, they must
alwaj-s be regulated according to the lowest order
for the same reasons as stated for columns, and so
that the modillions may principle or fall regularly
over each other. When arches are adorned with
columns or pilasters, with or without pedestals, the
columns or pilasters should be so disposed as to leave
sufficient space for the arch and its architrave. The
architrave round the arch is generally \ of the void
of the arch, and the impost the same. The impost
is similar to a capital, because it supports the
architrave.

This illustration also shows the method of dis-
posing the pedestals, piers, or dies, and the balusters
of a balustrade. The height of a balustrade is regulated
in a great measure by its use, and cannot well be
lower than 3 feet, nor should it be higher than 3 feet
6 inches or 4 feet ; nevertheless it must necessarily
bear some proportion to the rest of the architecture
as here defined by the upright scale. It will be seen
that the centres of the pedestals are in the same
perpendicular line with the axes of the columns, and
that the die of a pedestal is in the same perpendicular
line with the keystones of the arches. This die is
omitted and the balusters carried from pedestal to

204 IVas/cri/ig — f/aiii and Decorative.

Ijcdcstal w here windows or flat openin<,'s are used instead of arches as here shown. The plinths
on the top of the pedestals are used as stands for statues or vases which are sometimes used to
adorn fa(,-ades of buildings. When statues are placed upon a balustrade, their height should not
exceed one-quarter of the column and entablature on which the balustrade stands. The height of
vases should not exceed two-thirds of the height given to statues. This illustration also shows an
example of rustication. The method of .setting out and constructing this and other rustic varieties
has already been given.

With regard to the method of constructing this facade in Portland cement, the whole is executed
as alread}- described for the individual parts. It may be added that the three-quarter columns
should be ruled off before the walls are flanked in and the impost mouldings run, so as to allow the
curved and diminished surface of the columns to be more freely worked and carried into the brick
work. The wall surface being straight, can be more readil>- flanked, and the angles formed against
the circular surface of the column, than vice versA. The architrave mouldings should be run before
the impost mouldings are run. The whole of the facade must be made plumb by means of dots or
nails, and the jjositions of the columns, cornices, arches, and balustrade set out, measured, and
prt)ved before the running of mouldings is commenced. The work should be begun at the top and
finished downwards. This method allows the scaffold to be removed as the work proceeds, and the
putlog holes to be filled in and a complete section or bay to be fined in one operation. This
illustration will be of some service in setting out and constructing similar designs in cast artificial
stone, and for concrete formed in situ.

To CONSTKL'CT .\ BALUSTRADE. — Balustrades may be constructed either in situ, or cast and
then fixed in situ. When constructed /// situ, the balusters are always cast — in some examples the
cornice or rail over the balusters is also cast — and then fixed /// situ. Various methods are
emplo\'ed for constructing balustrades in situ. The one here given is one of the best. The most
difficult part of the process is the running of the cornice over the balusters. This operation and
the construction of the complete balustrade is elucidated by the subjoined illustration (No. 58).

The first part of the process is setting out the positions of the pedestals, also the dies, if there
are any in the design. The sides and upj^er surface of the base between the pedestals are floated,
care being taken to keep the sides parallel, and the top level. The base mouldings are run
before or after the balusters are fi.xed, according to the projection of the top of the base beyond
the balusters. A half baluster is then fi.xed on the flanks or inward sides of the dies, taking
care that they are central and plumb, as they form a datum or guide for fixing the intermediate
balusters. The positions or distance apart of the intermediate balusters are then set out on the
top of the base, and then a joggle is set out for each baluster. This done, a wood fillet about
I inch square, and in length equal to the distance between the dies, is fixed on the base and
against the plinths of the half balusters. A stout flooring board, or a piece of quartering
about 3 inches wide and li inches thick, is fixed against the upper plinth, taking care that
it is below the top of the plinth, to allow space for materials and the lower member of the
running mould when forming the cornice. It must also be fixed perfectly level, otherwise the
cornice will not be level. This is called a "rail-rule." If a flooring board is used, the slipper
of the running mould must be rebated, .so as to bear on the upper edge of the board. If a
piece of quartering is used, it must be planed on the outside, and a piece of ordinary running
rule fixed also on the outside to form a screed and bearing for the cornice running mould. The
top rail-rule is supported with wood props placed at intervals, and so arranged that they will
be in a line with the spaces between the balusters, so as to give more freedom when fixing the

Balustrades.

205

latter. The balusters are now fixed on the base, using the rail-rule and the fillets as guides for
keeping them linable, level, and plumb. Their proper position is further ensured bj- the aid of
marks which have previously been set out on the rail-rule and fillet, also by testing with a wooden
gauge. As soon as the balusters are fixed, a rail-rule similar to the first is fixed on the other out-
sides of the top plinths. This is supported by props as before. The outside and the inside rail-
rules are tied together by means of pieces of rule rebated at the ends, so as to clip the prop.s. A
core for the cornice, composed of tiles and cement, is now formed on the upper ends of the balus-
ters. This is effected by first filling in the joggles in the tops of the balusters with Portland
cement, allowing it to protrude sufficiently to form a bed for the first row of tiles. When this is
done, lay more cement on this row, and lay another row of tiles, and so on, until the desired size
and form of the cove is obtained. When Ia}'ing the tiles, break
the joints by overlapping, so as to obtain greater strength ; also
be careful to allow a sufficient space between them and the
profile of the cornice, so as to obtain a requisite thickness for
the cement with which the mouldings are formed. The average
thickness for this purpose is i inch. In no case should it be
less than | inch. If otherwise, the work is liable to crack or
laminate. This is an important point in the formation of brick,
stone, or tile cores, and also in the angles of brick work used in
buildings subsequently to be plastered, for unless the cement
work is of the necessary thickness to give it an independent
strength, the work will crack or scale. If the cement work is
too thin, the suction caused by the tile or brick work deprives
the cement of its necessary water before it has had time to
properly set, thus rendering it inert and weak. The laminations
to be seen in some of the work done in the early days of
Roman and Portland cements are due in many cases to a
sparseness in the thickness of the material.

A guide for regulating the projection of the core can be
obtained by cutting rough templates to the section of the
cornice, and fixing them on the dies, and then stretching a
cord over them. If the caps are on the pedestals, guides for
the core may also be obtained from the butt joints, which are
generally cast with them ; but if the caps are run in situ, the
profile of the cornice can be marked on the sides to act as guides.

After the core is made, fix a parallel rule on the top of the core to act as a nib-rule for the cornice
mould at each side. The top of the cornice is finished by hand, after the mouldings are run. For
parapets the top should have a fall of about h inch to allow rain to run off. Sometimes the top
takes the form of a flat curve or "saddle back." In this case the curve is formed with a cur\-ed
template. The rail-rules are now taken off, and the soffit of the moulding finished b>- hand.
After this the moulding on each side of the ba.se is run. This is done from a slipper running
rule fixed on the plinths and a nib-rule fixed on the bottom plinths of the balusters. F"or small
work, where there is not room for a nib-rule, the base mouldings are run from a parallel rule fixed
on the top of the base. In this case the mouldings are run before the balusters are fixed, and the
work must also be covered with wet sand or with boards to protect the mouldings from splashes

No. 58. — Balustrade Co.nstrixtiox.

206

Plastcriug — Phun ami Decorative.

and injun- while forming the work above. This is a general outline of the process for f..rming
balustrades /// situ, the details of which are as follows.

Take the pedestal on illustration Xo. 58 as one of the two pedestals between which it is
proposed to construct a length ..f balustrading. The elevation of the flank or inward side of a
pcde-stal is shown, but without the cornice. The. height and width of the pedestal is indicated b>'
the darts. The base. B, ma\- be cored out with brick work or concrete. If there is no brick work
pre\ iously made, then the plasterer should form the core with coarse concrete. Concrete for this
purpose is a more suitable material than either brick or stone. One-half of the core of this base
is shown as being formed with brick work, while the other half is made with coarse concrete. It
will be seen when concrete is used that only a thin coat of fining stuff is required on the concrete,
whereas a floating coat— as indicated by the fine dotted surface— is required on the brick work.
Having floated the sides and top of the base and run the mouldings, a section of the running
mould, M, and the slipper running rule, W, and the nib-rule, N, are shown in position when running
one side of the ba.se moulding. The half baluster is fi.xed on the die, D, keeping the lower i)liiilh
fair with the screed on the top of the base. E is the elevation and s is the section of the half
baluster. Repeat this on the other pedestal. This done, set out the positions of the balusters, and

1 ^

:z-i_ 1

No. 59. — Plain and Enrriied Bai.i'.s 1 ers. Kounu, Shuare, and Octagonal on I'lan.

cut a joggle for each on the top of the base. After this fix the top rail-rule, R, and the fillet, I',
and support the rail-rule with the props, r. Now fix the balusters, taking care to fill up the joggles
in the base and the balusters with Portland cement. The form of the joggles in the bottom end
of the balusters is indicated b}' the dotted lines at J, and a similar joggle is shown on the top plinth
and on the ba.se. After this fi.x the rail-rules on the other side of the balusters, and tie both sides
with the braces T, T. It will be understood that this is done at e\ery second or third prop, or as
often as may be found necessary to keep the rail-rules steady while both sides (jf the cornice are
being run. This done, form the tile core, C, as already described, then fi.x the nib-rule, NR, and run
the cornice. The running mould, M, is shown in position for running one side. The fine dotted
surface indicates the moulding material. After both sides of the cornice are run, take off the nib-
rules and the wood framing. Then finish the top and the soffit of the cornice, also the top and
sides of the base, by hand, thus completing a length of balustrading.

It may here be mentioned that in practice the top plinths of the balusters are generally less in
height than the bottom ones ; therefore the bottom member of the cornice is so arranged that it
will be below the top of the plinth, as shown by the running mould. This is constructed in this
way for a twofold purpose — first, to allow a sufficient thickness of cement on the soffit of the first

Enriched Balusters and Pierced IVork.

207

row of tiles ; and secondly, to form a strong bond between the cornice and the balusters. This will
be seen when the bottom line of the lowest member of the cornice is carried through to the other
side of the balusters, and that they are embedded about i inch into the soffit of the cornice.

As already mentioned, the cornice as well as the balusters are in some instances cast and then
fixed on the base, which is run in situ. The whole of the balustrade may al.so be cast and then
fixed in situ. This method is useful for additions to buildings, gardens, &c., to avoid time and dirt
on the building and the adjoining work. When balustrades are cast, the dies and the half balusters
on the flanks should be cast in one piece. For large work the cap of the pedestals should be cast
separately, so as to decrease the weight when casting and fixing, also to give more freedom to fix
the other parts of the work. " Butt " joints should be made on the caps, so as to joint with the
cornice or rail on the balusters, and also on the moulding of the base of the pedestals, so as to joint
with the base under the balusters. A section of a butt joint on the base of a pedestal is shown at
A. The joints of the cornice and base casts should be made to come over the centre of a baluster,
and joggles should be formed on the ends of both, and also on the upper surface base and the under
surface of the cornice for fi.xing purposes. The joggles are of course made in the models before
they are moulded. With different spaced balusters, as sometimes used for different works or
positions, a sinking from end to end can be made in the models of the rail and base, and after the
balusters are fixed the intervening sunk spaces are filled in and ruled off flush with the main
surfaces. It will be seen that this
method forms a continuous joggle,
allowing the balusters to be fixed
at any desired place, and yet have
joggled fixing points on the base
and rail casts.

Ornamental Balusters
AND Pierced Work. — On the
introduction of Roman and similar
cements balustrades composed of
cement were largely employed in London and many provincial towns for the decoration of garden
walls, balconies, terraces, house tops, &c. Designs of some of the balusters used for this purpose
are shown on the appended illustration (Xo. 59). Fig. I shows an enriched double-bellied
baluster ; Fig. 2 is plain, and square on plan ; Fig. 3 enriched, square on plan ; Fig. 4 plain,
octagonal on plan ; Fig. 5 enriched, octagonal on plan ; Figs. 6, 7, and 8 enriched, circular on
plan. Balustrades are sometimes enriched with pierced work, having enriched surfaces, with a run-
ning or interlaced pattern, and are used in place of balusters. Three examples of this form of
decoration are shown on illustration No. 60.

Windows. — Designs somewhat similar to the windows in the annexed illustration (No. 61)
are often found in Portland cement facades. Fig. i is from St Peter's, Rome, and was designed by
Michael Angelo Buonarotti in the early part of the sixteenth centur}-. In height the aperture is
somewhat less than a double square ; the architrave is one-seventh the width of the aperture, and
is likewise the breadth of the pilasters ; the consoles, commonly called trusses, both at top and
bottom of the window, are in length one-third the width of the aperture ; and the whole entablature
is equal to one-quarter thereof Fig. 2 is from the Mattei Palace at Rome, and was designed
by B. Ammanati, 1569. It will be seen that the upper part is finished with a curved weathering
instead of a pediment. Fig. 3 was designed by Buontalenti about 1575, and executed in different

No. 60. — Three E.\amples of Pierced Work for Balustrades.

2o8

Plastering — Plain and Decorative.

places. The aperture of this sort of window is generally a double square ; the architrave one-
seventh the width of the aperture, and the pilasters about the same. The height of the whole
entablature is about one-quarter the height of the aperture, and the consoles may be equal in
length to half the width of the aperture at the most, and to one-third of it at the least.

When constructing these kinds of windows in Portland cement the entablature is the first
part done, this being e.\ecuted in the same way as described for pediments. The pilasters and
architraves are generally run in one operation ; from a running rule fixed on the wall for the slipper
of the mould, and from a running rule fixed on the reveal of the window for the nib of the mould.
A separate running mould (formed without the pilaster moulding) is generally required to run the
horizontal part of the architrave. Wide pilasters are sometimes run from a parallel running rule
fixed in the centre of the pilaster. The sill moulding is next run, then the trusses and other
enrichments are fixed. The breaks in the top of the architrave, as shown in Fig. 2, are run down.

■Bt

-'*?'

Nri. 6i.— KoRMi.NG Windows.

cut to the required lengths and mitres, then planted. It will be understood that all mitres are
made while the work is " green," so as to obtain a uniform colour.

Window He.xd. — The annexed illustration (No. 62) shows the cle\ation and sections of a
window in the French style. The wall is first screeded and then flanked in ; then the cornice is
run from a running rule fixed on the frieze at A, and a nib-rule fixed on the weathering at B. The
necking moulding is run from a running rule fixed on the wall at C. The return mitres of the break
are worked up by hand. The window architra\e moulding can be run from a running rule fixed on
the wall at D, and a nib-rule fixed on the reveal at E, and the segmental part run with a radius-rod
mould, or the vertical and segmental parts can be run with a twin-slippered mould. The latter
way would form the whole or a part of the reveal, and thus save screeding same. The sinkings on
the wall at F are cut out of the floating, and then run so as to form a finished sinking with straight
angles and arrises. The surface is fined as soon as the run parts are .'=et. If there are a large

JVindo-dJS.

209

number of windows of the same design on the building, the shield on the window head and the
enrichment in the sunk panel at the side may be cast and planted, but the swag of fruit and
flowers, the spray of leaves, and the scroll ends should be modelled in situ. This would offer a greater
variety of details, and add to general effect. If there are only a few windows in the building, the
whole of the enrichments should be modelled in situ. It is false economy in this class of work to
model, mould, cast, and plant an enrichment, when the whole could be done in one operation. The
work would be equally as durable, and certainly more effective and artistic, and in most cases less
expensive than cast work.

Dormer Window. — Illustration Xo. 63 shows the elevation and sections of a side of a
dormer window in a modern style. If brick is employed for the constructional work, screed the
pier (a) to form a plumb ground for the mouldings. The head cornice (c) and the architrave (b)
are run as set forth for window heads. In this case a circular running rule is required for the

No. 62.— F0R.MING Wi.NDOw Heads.

cornice, but this and the segmental part of the architrave can be run with a radius-rod mould. The
sill moulding is run from a running rule fixed on the wall at D. The band (e) and the outline of
the scrolls at F, F, are formed b>- the aid of two templates which should be fixed on the side of the
window, and then the intermediate space fixed in, and then ruled off flush with the templates.
The outline of the apron below the window sill is formed with a template (cut to the desired curves
and thickness), fixed on the wall at D. The enrichments on this and the side of the window may
be either cast or modelled in situ; the latter for preference.

To Set Out ax Elizabethan Gable.— The method of setting out a gable is elucidated
in illustration Xo. 64, and is as follows :— Let a b be the base line ; bisect it in c, and erect
the perpendicular line c d. From c measure to d, and draw the line // parallel to a b. From d
measure to e, e, and /,/; from c measure to^, and from g, with radius g h, describe the quadrant
k in. From m draw m i parallel \.o c d ; from/, with radius /«, describe the arc meeting the line /.
Finish as shown in the left part of the sketch. The same method is adopted for setting out the

2IO

Plastering— Plain ami Decorative.

The wooflcn nib-

surface offers a fine field for
in situ with

curved templates or running rules from which the mouklin-s arc run. An allowance must be made

for the width of the slipper, from the inner line of the moulding to the running edge of rule. A nib

running rule must be fixed on the outer surface of the moulding, as shown at p, to act as a bearing

for the nib of the running mould. The circular mouldings as n i and vi h should be run first so as

to avoid circular mitres. The circular wall rules should extend bcj-ond the intersections, as shown

at r, so as to allow the circular mouldings to be run right up to the mitres. It is sometimes

necessar>- to extend the nib-rule beyond the intersection for a similar purpose.

rule ma>- be extended by adding gauged plaster, and ruling it off flush

with the edge of the wood ])ortion. This circular moulding could also

be run with a radius mould from the centre^, but as there would be no

ground for a centre, as at/ on the actual work to run the inverted or top

circular moulding, it is therefore better to run both mouldings from wall

running rules as already described. The straight mouldings are next run

and the mitres " put in." The wall or gable surface and the cornice

weathering arc then fined. A gable

effective decoration. The decoration may be formed

modelled Portland cement, or with sgraffitto work.

Rough C.\ST. — Rough cast derives its name from the fact that the
material is cast, or dashed on, leaving a rough surface. In some districts

it is known as "pebble da.shing," and in Scotland it is called "harling."

It is one of the oldest forms of external plastering. Many of the old
timber houses of the Tudor and Stuart times have the spaces between

the timbers filled in with rough cast. This kind of plastering is very

durable, and many old examples are still to be found in good preserva-
tion. Gravel or shingle is the usual material for the surface work,

but coloured glass, broken potterj^ pebbles, spar, and flints have been

used with good effect. The plaster for the upper coat has also been

coloured where the stone has been sparsely used. By combining

varied coloured stones and margins, a variety of treatment may be

obtained in this description of plastering. Margins and bands may

also be varied and enriched by impressing with ornamental stamps ;

also by stubbing with a stump or nearly worn-out birch broom.

Rough cast is performed by first rendering the wall with a coat

of strong-haired "coarse-stuff," and then scratching it to give a key

for the second coat. This is not laid on until the first is dry. The

second coat is also composed of coarse-stuff, well knocked up, and

made of an even consistencj-. It is laid fair, and while still soft

the shingle is quicklj- and evenly thrown or dashed on with a

" scoop " or hollow trowel, then brushed with the liquid to give a uniform tint. A good

craftsman can dash the shingle very regularly, and leave the face of the work with a uniform,

though rough surface. The dashing should be begun at the top, gradually working down, taking

in all angles and sides of panels. The gravel, shingle, or other stone, should be well washed and

passed through a sieve (from J-inch to i-inch mesh). The shingle is then put into a tub containing

hot lime (hydraulic for preference) and water in a .semi-fluid state. This mass is well stirred, and

taken out as required. Common rough cast is done on one coat of lime plaster ; the shingle

No. 63.

-FoRMiNO Dormer
Window.

Sgraffitto.

211

is washed and passed through a j'-inch sieve and then dashed on the soft lime plaster. In some
districts the walls are not plastered, the shingle mixed with thick liquid lime being simply dashed
on the bare walls. For exposed positions, Portland cement may be substituted for the coarse-stuff.

Depeter.— Depeter is similar to rough cast, and consists of forming a fair surface with coarse
stuff or Portland cement. As soon as laid, a hand-float is passed over the surface a few times to
give an even and uniform texture, and while it is soft, pressing in by hand small pieces of stones,
broken flints, pottery, spar, glass, sea-shells, or marble. The design may be varied and enriched by
using various coloured pieces in forming margins, bands, or other ornamentation. On the contrast
of colours and the broad and vigorous treatment of the bands depends the effect of this class of
work. A combination of depeter and rough cast may be used with good effect.

Depretor.— Depretor is a term sometimes used to denote plaster finish in imitation of stone.

Sgraffitto.— Sgraffitto or " grafi^tto " is an Italian word, and means " scratched." Scratched
decoration is the most ancient mode of surface decoration employed by man. The primitive
savage of the flint-weapon period used this simple form of ornamentation. Scratched work, as
used b)' prehistoric man, may be

fitly termed the proem of the ^ ^ IcZ-

civilised arts of drawing, modelling,
and sculpture. The term is now
employed for plaster decorations,
scratched or incised upon plaster
or cement before it is set. It may
be used for both
external and in-
ternal decoration.
The anne.xed illus-
trations (Nos. 65
and 66) will demon-
strate the high de-
gree to which the
art of sgrafiitto

attained in Italy. Good English examples are to be seen at the Choir Schools of St Paul's Cathedral
and the School of Music, near the Albert Hall. Different methods and materials for sgraffitto are
to be seen at the Science and Arts Schools, South Kensington. This experimental work was
executed by the Arts students in 1871, from designs by T. W. Moody. The work covers a large
area of e.xterior wall surface, with a great variety of artistic designs and execution. The colours
in the greater portion of the work retain their original freshness. In a few instances the colours
in the panels have faded. This is probably due to the materials experimented with.

Some of the graffittos at South Kensington are really low relief work rather than sgraffitto,
they being very deep cut with the iron or steel point, which was necessitated by the final coat being
plastered on instead of washed on. Deep cutting gives a hard appearance to the design, prevents
the water from running off the walls, and catches the dirt. In executing true sgraffitto, the cut or
scratch should be exceeding!}- slight — in fact, in some parts scarcely perceptible. At South
Kensington the work is a little darker than when first executed, still it is perfectly distinct. Time
seems to have gi\en it a finer tone.

These examples afford good e\idence that sgraffitto decorations do not suffer materially from

Setti.vg out ax Elizabetii.w Gable.

212

Plastering — Plain and Decorative.

No. 65.— Sgrakfitto Frieze from Florence.

time and atmospheric changes. Sgraffitto is extensively used on the Continent, especially in
Germany and Italy. Its limited use in Great Britain is probably due to erroneous impressions
that it would not resist our variable climate, and that it would prove too expensive for general use.
Examples herein named tend to jjrovc that it is a durable and inexpensive decoration. Vasari
says : " Artists have another art, which is called graffitto. It is used to ornament the fronts of
buildings, which can thus be more quickly decorated, and gives greater durability and resistance to
rain, in consequence of the etching on the wall being drawn in colours. The cement is prepared
and tinted, and forms the background, and is subsequently covered with a travertine lime-wash, the
lines being afterwards .scratched in with an iron stilus." " liackgrounds are obtained," the same author
says, "by the entire removal of the surface wash," and he describes how strong projecting shadows for
foliage, fruit, and grotesque figures may be obtained by adding stronger shades of the colour to the
background. In some backgrounds, colours in monochrome are sometimes added, and these are
treated in a similar way to fresco. This is simple after experience has taught the difference between
the tint in its wet and dry state. Fine and rich effects are obtained by the addition of gilding to
some of the prominent parts of the design. The gold, however, must be added when the sgraffitto
is perfectly dry. When properly manipulated, .sgraffitto is quite capable of resisting heat, rain, and
frost, because it offers a very hard surface, and is much less porous than ordinary stones or bricks.
It can also be easily washed when begrimed by smoke or fog. As to the question of cost, it will
compare favourablj- with any other external decoration.

The beautiful examples of .sgraffitto work, shown in the annexed illustrations (\os. 67, 68,
and 69), were designed by and executed f^r Mr G. T. Robinson, F.S.A. These highly artistic
works should amply demonstrate and convince the most sceptical as to what can be done in this
mode of decoration ; also that our British artists are not behind their foreign rivals both in
conception and execution.

These examples are a combination sgraffitto with fresco, and I cannot do better than give the
modus operandi in the artist's own words : " In my own practice as an architect and decorator,
I have, during the last fifteen or twenty years, used sgraffitto somewhat extensively for both
external and internal adornment, and most of that which I have done is still in perfect condition,
even in grimy London. The mode adopted has nothing new in it ; in fact, Vasari's instructions
hold good to this day, excepting that I use ordinary materials, and find the simplest the best. The
wall is prepared in the ordinary way. A rough coating of Portland, mixed with three times its
quantity of good sharp sand, is, for external work, laid on and finished with a roughened surface, by

Sgraffitto.

213

No. 66. — Sgraffitto Frieze from Rome.

stubbing it with an old birch besom, leaving it barely half an inch from the finished face. For
internal work, the ordinary pricking up suffices. When this is drj', a thin coat of selenitic lime,
mixed with the desired colouring matter for the background, is floated over it. This background
may be black — bone-black being used ; red, for which j'ou may use Venetian or Indian red, or the
ordinary purple brown of commerce, singly or mixed, to produce any tone you may desire ; yellow,
produced by ochres or umbers ; blue, by German blue, Antwerp blue, or any of the commoner
blues, avoiding cobalt, and these colours you may use to any degree of intensity or paleness.
When this coat is nearly dry, you skim over it a ver}- thin coat of pure selenitic lime, which dries
of a parchment colour, and generally suffices. If you want a pure white lime, use a moderate
quick-setting one, as stiff as you can work it, and as each variety of lime has its own individual
perversity, I can give no general direction, and would advise the beginner to stick to selenitic,
which is always procurable. You have, of course, prepared }'our cartoon. This is pricked and
pounced as for any other transfer process, and then with an old, well-worn, big-bladed knife, for
there is no better tool, you can cut round all the outlines, and with a flat spatula clear awaj' all
the thin upper coat, leaving the coloured ground as smooth as you can. If your plaster is not quite
dry enough for the two coats to separate easily, wait a little longer, but not too long, for that is
fatal. By the time you have cleared out your background, the plaster will be in a good condition
to allow you to cut out the finer parts of the design, such as the folds of the draperies, or the finer
lines of the faces or of the ornament. Use your knife slightly on the slope, and if you want to
produce half-tones, slope it \ery much ; but, as a rule, the more you avoid half-tones, and the
simpler and purer your line, the more effective your work will be. Recollect, above all things,
you are making a design and not a picture, and you must never hesitate, for to retouch is
impossible. Sometimes it may be desirable to gild the background, and you can then carve or
impress it with any design \ou choose. It occasionally happens you want to give some semblance
of pictorial character to your work when it is small in scale and near the eye, and then }-ou can
proceed as though you were cutting a wood-block. The series of the Four Seasons in a porch at
Maidenhead (illustrations Nos. 6"}, 68) illustrate this treatment."

" By cutting out your ground colour in places, and plastering it with that of another colour,
you may vary any portion of it you desire. You can also wash over certain parts of \-our upper
coat with a water-colour if j-ou desire, combining fresco with the sgraffitto, both of which manners

:!'4

Plasteyi)ig — Plain and Decorative.

arc used in the Southport rotable (illustration \o. 69;; but, as a rule, the broader your design, and the
simpler your treatment of it, the better. It will be seen that this process is very available for simple
architectonic effects ; and for churches, hospitals, and other places where large surfaces have to be
covered, it is the least costly process that can be adopted. It has also the great advantage of being
non-absorbent, and it can be washed down at any time. At Messrs Troliope's establishment in London
there is a specimen which for two years was fi.xed up outside their heating apparatus chimney,
exposed to all weathers, under the adverse circumstances of rapid changes of temjierature, and it
was naturally encrusted with soot. It has simply been washed, and presents a very fair illustration

SPRlsr..

SUM.MEK.

.\LTUMN. Winter.

Nos. 67 AND 68.— Sgraffitto Panels. The Four Seasons. By G. T. Robinson, F.S.A.

of how enduring this mode of decoration is, and how well fitted for external decoration of town
buildings. The artist is untrammelled by difficulties of execution, but he should bear in mind that
the more carefully he draws his lines, and the simpler he keeps his composition, the more charmed
with the process he will be, and the better will be the effect of his work."

Mr Heywood Sumner, a well-known artist, records his experience of sgraffitto as follows : —
" Rake and sweep out the mortar joints, then give the wall as much water as it will drink, or it will
absorb the moisture from the coarse coat, as it will not set, but merely dry, in which case it will be
worth little more than dry mud. Care should be taken that the cement and sand which compose

Sgraffitto.

215

the coarse coat should be properly gauged, or there may be an unequal suction for the finishing
coats. The surface of the coarse coat should be well roughened to give a good key, and it should
stand some days to thoroughly set before laying the finishing coats. When sufficiently set, fix
your cartoon in its destined position with nails ; pounce through the pricked outline ; remove the
cartoon ; replace the nails in the register holes ; mark in with chalk spaces for the different colours,
as indicated by the pounced impression on the coarse coat ; lay the several colours of the colour
coat according to the design as shown by the chalk outlines ; take care that in doing so the register
nails are not displaced ; roughen the face in order to make a good key for the final coat. When
set, follow on with the final surface coat, only laying as much as can be cut and cleaned up in a
day. When this is sufficiently steady, fix up the cartoon in its registered position ; pounce through
the pricked outline ; remove the cartoon, and cut the design in the surface coat before it sets ; then

No. 69. — Retabi.e at .Southport. By G. T. Roisinsox, F..S..\.

if the register is correct, cut through to different colours, according to the design, and in the course
of a few days the work should set as hard and as homogeneous as stone, and as damp-proof as the
nature'of things permits.

" When cleaning up the ground of colour which may be exposed, care should be taken to obtain
a similar quantity of surface all through the work, so as to get a broad effect of deliberate and cal-
culated contrast between the trowelled surface of the final coat and the scraped surface of the
colour coat. The manner of design should be founded upon a frank acceptance of line, and upon
simple contrasts of light against dark, or dark against light. The following are the proportions of
the various coats : —

"Coarse coat — i of Portland cement to 3 of washed sharp coarse sand.

"Colour coat — iJ of air-slaked Portland to i of colour laid | inch thick. Distemper colours are
Indian red, Turkey red, ochre, umber, lime blue ; lime blue and ochre for green ; oxide of man-

2i6 P/as ferine — P/nin ond Decorative

ganese for black. In using lime blue, its violet hue may be overcome by adding a little ochre. It
should be noted that it sets much quicker and harder than the other colours named.

" Final coat, internal work— I'arian, air-slaked for twenty-four hours to retard its setting, or
Aberthaw lime and selenitic sifted through a fine sieve.

"For external work — 3 .selenitic and 2 .silver sand.

"When finishing, space out the wall according to the scheme of decoration, and decide where to
begin, and give the wall in such place as much water as it will drink ; then lay the colour coat, and
leave sufficient key for the final coat. Calculate how much surface of colour coat it may be
advisable to get on to the wall, as it is better to maintain throughout the work the same duration
of time between the laying of the colour coat and the following on with the final surface coat ; for
this reason, that if the colour sets hard before laying the final coat, it is impossible to get up the
colour to its full strength wherever it may be revealed in the scratching of the decoration. When
the colour coat is quite firm, and all shine has passed away from its surface, follow on with the final
coat, but only lay as much as can be finished in one day. The final coat is trowelled up, and the
design is incised or scratched out. Individual taste and experience must decide as to thickness of
final coat, but if laid between J inch and I. inch, and the lines cut with slanting edges, a side light
gives emphasis to the finished result, making the outlines tell alternately as they take the light or
cast a shadow."

Another method which I have used in sgraffitto for external decoration was done entirely with
Portland cement. This material for strap-work or broad foliage, or where minuteness of detail is
unnecessary, will be found suitable for many places and positions. Three colours may be used if
required, such as black for the background, red for the middle coat, and grey or white for ttu' fmai
coat. These colours may be varied and substituted for each other as desired, or as the design
dictates. The Portland cement for floating can bo made black by using black smithy ashes as an
aggregate, and by gauging with black manganese if for a thin coat. The red is obtained by adding
from 5 to 10 per cent, of red oxide, the white by gauging the cement with white marble dust, or
with whiting or lime, the grey being the natural colour of the cement. After the first coat is
laid, it is kc\-ed with a coar.sc broom. The second coat is laid fair and left moderately rough with a
hand-float. The suction of the first coat will give sufficient firmness to allow the third coat to be
laid on without disturbing the second. The third coat should be laid before the second is set hard.
The second and third coats may be used neat, or gauged with fine sifted aggregate as required.
The finer the stuff, the easier and cleaner the work, and the cut lines are more accurate and free
from jagged edges. The outlines of the design may be pounced or otherwise transferred to the
surface of the work, and the details put in by hand. The thickness of the second coat should be
about ^'V inch, and the third coat about \ inch. The thickness of one or both coats may be varied to
suit the design. The beauty of effect of this method of linear decoration, aided by two or three
colours, depends greatly on the treatment of design, the clearness of the incised lines, anfl the
pleasing colour contrasts. It will be seen that in the three methods described there is a similarity,
yet the method of using two colour coats on a dark floating coat will give more variety and effect.
There is a large use for sgraffitto in the future, as it has been in the past, and its use is intimately
bound up with the future of cement concrete.

In order that the foregoing e.xamples of high-class sgraffitto may not deter the young plasterer
from trying his '"prentice han'" in this class of work, some simple designs are given in the annexed
illustration (No. 70). Fig. i shows a design for a frieze in two colours. The ground may be black
or red, and the ornament buff or grey. The coloured material for the ornament is laid first, and the

Sgraffitto.

217

coloured material for the ground laid last. F"ig. 2 shows a design for a cove in two colours, one with
two shades. The ground is grey, and the band work buff. A deeper shade of buff for the honey-
suckle can be obtained by brushing this part with liquid colour made deeper than the original
gauge, also by laying a black coat first, and in a line with the honeysuckle; then laying the buff
stuff for the band work next, and then laying the grey colour last. In the latter case the honey-
suckle is cut deeper than the band work, so as to expose the black coat.

The annexed illustration (No. 71) shows a design of an ornament with mitre for a panel
moulding in two colours, the ground black and the ornament red. The red colour is laid first, and
the black next. Other colours may be substituted as required. Illustration No. 72 shows a
design for a frieze or a panel ornament in three colours with shading tints. The first ground (i)
is dark brown, the second ground (2) buff, and the fleur-de-lis leaf work (3) white or a light grey.
The patent and balls are also white or grey, with a black ground. The band work is the same
colour as No. 2 ground. This may be tinted a darker shade by brushing it with a darker
solution than used for the ground.
Different effects can be obtained
by changing the colours. Sec-
tions of the surface of the frieze
and part of the moulding are
shown at the ends.

Designs forsgraffitto borders
are depicted in the annexed illus-
trations (Nos. 73 and 74). These
designs are bold and effective,
and are composed in two colours.

Fresco. — The plasterer is
closely allied to the artist painter.
He has alwaj^s to be in readi-
ness to plaster the wall for the
artist. Owing to the alliance
with distinguished artists, and the
various methods of preparing
and using the plaster materials,
I am induced to give a few notes,

also extracts from writers of authority. Fresco is a mode of painting with water-colours on
freshly laid plaster while it remains naturally wet. The colours incorporate with the plaster, and
drj-ing with it, the work becomes ver\- durable. It is called '" fresco " either because it was originally
used on buildings in the open air, or because it was done on fresh plaster. Fresco is an ancient
art, being mentioned by Pliny. Mr Flinders Petrie found some remarkably fine specimens on
floors and walls at Tel-el-Amarna, which reveal the state of the art 3,300 years ago. Fine frescoes
were discoxered in the ruins of Pompeii. In one of the principal houses the plaster walls are
adorned with theatrical scenes ; in an inner room is the niche often to be seen in Pompeian houses.
The frescoes on the walls consist of floral dados. Above this is a whole aquarium, with shells, plants,
birds, and animals. They are all executed in their natural colours, and are naturally and grace-
fully drawn. Michael Angelo's beautiful fresco on the ceiling of the Sistine Chapel in the Vatican
is grand both in conception and execution. It measures 133 feet in length by 43 feet in width

No.

Fig. 2.
70. — SoKAFiri'TO Frieze in Two Colocrs.

2l8

Plastering— Plain and Decorative.

No. 71.— SORAKKITTO FRIEZE IN TwO COLOURS.

Raphael's frescoes in the Vatican, Farnesina Palace, &c., are wonderfully fine, and ma>- be regarded
as the high-water mark of Cinque Cento decoration. Raphael was assisted by Giovanni da Udine
and Giulio Romano, who were also artists in stucco. There arc two large frescoes by Maclise feach
45 feet long and 12 feet high) in the House of Lords. The fine frescoes recently executed by Sir
Frederick Leighton, in the South Kensington Museum, are admired by all classes of art lovers-
The annexed illustration (No. 75) shows part of a ceiling (the centre panel is fresco), taken
from a design b\- M. Ch. Licnard.

For fresco or biton fresco the lime has to be carefully run, and the sand should be white, clean,
and of even grain, being well washed and sifted to free it from impurities or saline properties.
Silver sand is preferred by some artists. The older the putty lime, the better the results. The
lime is slaked in a tub, and then run through a fine wire sieve into a tank, and after being covered
up, is left for three months. It is then put into the tub again, and rc-s!aked, or rather well worked,
and run through a fine hair sieve into earthenware jars or slate tanks, and the water which collects
at the top drawn or poured off, the jars or tanks being covered over to exclude the air. Lime
putty in this state will keep for an indefinite time without injury. A large quantity of old putty
for fresco purposes is, or was latel)-, kept in the cellars of the Houses of Parliament. The propor-
tions of the putty and sand will vary somewhat according to the circumstances and (particularly)
according to the quality of the lime. From 2 to 4 parts of sand to i part putty is usual. Marble dust
alone is sometimes used in place of sand, and also with sand in equal parts. Every difference of
lime and sand found in various localities should be considered and tested before using. A soft sand
is quickly dissolved b_\- a strong lime, and a jjlaster made of this is fit for use .sooner, and will
deteriorate more quickly, than a plaster made with a less powerful lime and a harder sand, or with
marble du.st.

The wall surface to be plastered must be well scrajicd and hacked, the joints raked out and
brushed, and the whole surface well scrubbed and wetted. The rendering is done with the best
possible prepared old coarse stuff". If the walls are rough or uneven, they should be first pricked
up, and then floated. In any case, the surface is left true, and with a rough face, to receive the
finishing coat. Portland cement or hydraulic lime gauged with sand, also gauged with coarse stuff,
has been used where the walls were damp (damp is fatal to fresco), or if exposed to the atmosphere.
When Portland cement or hydraulic lime is used, the work should be allowed to stand until
thoroughly dry to allow any contained soluble saline efflorescence to come to the surface. This is
brushed off with a dry brush, and a few days are allowed to elapse to see if there is a further

Fresco.

219

No. 72. — Sgraffitto Frieze in Three Main Colours and Shading Tints.

efflorescence. When this is all extracted and swept off, and the artist is ready to commence, the
wall is washed with a thin solution of the fine setting stuff, and then laid about | inch thick, with
well-beaten, worked, and tempered fine setting stuff. It is then rubbed with a straight-edge and
scoured with a hand-float (using lime water for scouring) until the surface is true and of a uniform
grain. Most artists prefer a scoured surface without being trowelled. No more surface should be
covered than can be conveniently painted in one day. While the plaster is still soft and damp, the
cartoon is laid on, and the lines and details pounced in or indented by means of a bone or hard-
wood tool. Should the finishing coat get too dry in any part, it can be made fit for work by
using a fine spray of water. The method of plastering and the gauging of materials may slightly
vary according to the desire of the painter and the kind of fresco in hand. The following is taken
from an old manuscript in the Soane Museum, dated 1699: —

" I. In painting the wall to make it endure the weather, you must grind colours with lime
water, milk, or whey, mi.xed in size.

" 2. Then paste or plaster must be made of well-washed lime, mi.xed with powder of old rubbish
stones. The lime must be often washed till finally all the salt is extracted, and all >-our work must
be done in clear and dry weather.

" 3. To make the work endure, stick into the wall stumps of headed nails, about 5 or 6 inches
asunder, and by this means you may preserve the plaster from peeling.

"4. Then with the paste plaster the walls a pretty thickness, letting it dr\- ; but scratch the
first coat with the point of your trowel longways and crossways, as soon as j-ou have done la)-ing
on what plaster or paste you think fit, that the next plastering you lay upon it maj- take good
key, and not come off nor part from the first coat or plastering ; and when the first coat is dry,
plaster it over again with the thickness of half a barleycorn, ver\- fine and smooth. Then, your
colours being already prepared, work this last plastering over with the said colours in what draught
or design you please — history, &c. — so will your painting unite and join fast to the plaster, and dry
together as a perfect compost.

" Note.— YoMx first coat of plaster or paste must be very haired with ox-hair in it, or else
your work will crack quite through the second coat of plastering, and will spoil all your painting
that you paint upon the second coat of plastering ; but in the second coat that is laid on of paste
or plaster there must be no hair in it at all, but made thus :— Mix or temper up with well-washed
lime, fine powder of old stones (called finishing stufQ and sharp grit sand, as much as j-ou shall

220

P/asfcriiig — Plain and Decorative.

TT Tl T UT ITll IIII IIXI T i ll— IIII IIIi :

No. 73. — SoRAFKirro Border in Two Colours.

have occasion for, to plaster over your first coat, and plaster it all very smooth and even, that no
roughness, hills, nor dales, be seen, nor scratches of your trowel. The best way is to float the
second coat of plastering thus: — After you have laid it all over the first coat with \our trowel as
even and smooth as possible, you can then take a float made of wood, verj- smooth, and i foot long
and 7 or 8 inches wide, with a handle on the upper side of it to put your hand into to float your
work withal, and this will make \-our plastering to lie even ; and lastl)-, with j-our trowel you may
make the said plastering as smooth as can be.

" 5. In painting be nimble and free ; let your work be bold and strong ; but be sure to be
exact, for there is no alteration after the first painting, and therefore heighten your paint enough at
first ; you may deepen at pleasure.

" 6. All earthy colours are best, as the ochres, Spanish brown, terra-vert, and the like.
Mineral colours are naught.

" 7. Lastlj", let )-our pencils and brushes be long and soft, otherwise your work will not be
smooth ; let your colours be full, and flow freel)- from the pencil or brush ; and let your design be
perfect at first, for in this there is no alteration to be made."

Fresco Secco. — Closely allied with the genuine fresco {fresco buond) is another kind called
fresco secco {^xy), ox mezzo {^■aX^) fresco. The plaster work hr fresco secco is similar to that used
ioT fresco buono. It is allowed to stand until thoroughly dry. The surface is then rubbed with
pumice-stone, and about twelve hours before the painting is commenced it is thoroughly wetted
with water mi.xed with a little lime. The surface is again moistened the next morning, and the
painting begun in the usual way. If the wall should become too dry, it is moistened with the aid
of a syringe. There is no fear of joinings in the painting being observable, and the artist can quit
or resume his work at pleasure. Joinings are distinctly noticeable in the frescos in the Loggia of the
Vatican. Fresco secco paintings are heavy and opaque, whereas real fresco is light and transparent.
While the superiority oi fresco biiono oxer fresco secco for the highest class of decorative painting is
unquestionable, still the latter is suitable for many places and forms of decorative paintings. The
head by Giotto in the National Gallery, from the Brancacci Chapel of the Carmine at Florence, is
\n fresco secco.

Indian Fresco and MAKin.r. Plaster. — " Fresco painting is a common mode of decoration

Marble Plaster.

22 I

Xo. 74. — Si;kai FiTTO Border in Two Col. irK-~.

in Jeypore, and is used in ornamenting walls inside and outside of buildings — also as a dado or
border round the wainscot or on the floor — and on any surface where decoration is desired. The
beautiful marble plaster on which it is done is common in Rajputana, and is used to line the surface
of walls or floors, and of baths or bath-rooms. It is admirably adapted to places where coolness
and cleanliness are desired, and is very suitable to a warm climate. It would no doubt be more
commonly used if pure lime could be obtained.

" To prepare the marble plaster, the process in use in Jeypore is as follows : — Take pure stone
lime, mix it with water until it has dissolved, then strain it through a fine cloth. In Jeypore the
lime is made from pounded marble chips or almost pure limestone. The substance which remains
in the cloth is called biijra, and all that passes through the cloth is called ghole. These should be
prepared a few days before they are required so as to allow time to settle, and every day the water
should be changed, so as to leave a very fine sediment.

" finki, which is also used, is pure marble ground to a very fine dry powder ; kurra is a mi.xture
of bujra and jinki ; 3.ndjinkera is a mi.xture of ghole and kurra. These are the materials used, and
the names by which they are known in Jeypore. In Madras, where similar plaster is used, it is
made, I believe, from shells, and the ingredients are probably known by other local names.

" If the surface to be polished is a slab or stone, the kurra mixture consists of i part by weight
of bujra and i-l parts of jinki. If the surface is a wall or a chunam floor, it must be first thoroughly
dry and consolidated — then take equal parts of bujra and jinki to form the kurra mixture. .Mix
the bujra and the jinki well together ; add a little wa,ter, and grind them well together, in the same
way as natives mix their condiments, by hand with a stone rolling-pin on a slab, until they form a
perfectly fine paste. Wet the surface which is to be polished, and spread over it a layer of this
kurra mixture, about \ inch thick. Then beat the surface gently with a flat wooden beater, sprinkling
a few drops of clean water on the surface occasionally. Then mix a little ghole with the kurra
plaster (described above as jinkera) and lay it on evenly with a brush as if it were a coat of paint ;
rub the surface over carefully with any close-grained flat stone, called in Jeypore jhaon. The
object of this is to smooth down all irregularity and roughness, and to prepare a smooth even
surface. Sprinkle a few drops of water and repeat the process, taking care that no hollow places
are allowed to remain. Paint it over with fine jinkera (ghole and kurra mixed), increasing the

222

Phistcritig—FIaiu and Decorative.

proportion of gholc.and rub it down well with a flat stone Qhaon) as before ; then paint it over with
ghole only, after each coat rubbing it down carefully with the (jhaon) stone. After this, rub it all
over with a soft linen cloth, called in Jeypore nainsiikh, folded into a pad. Then give it another
coat of ghole, and now rub it down carefully with a piece of polished agate, called in Jeypore
ghunti, until it begins to shine. The surface must not be allowed to dry too rapidly, or a good
polish will not be obtained. Care must be taken that the lime has been thoroughly slaked in the
first instance, or it may blister ; also that the surface, if a floor, is thoroughly consolidated, as the
least settlement naturally causes the plaster to crack. The i:)olishing process with the agate cannot

No. 75.— Plaster Ceiling (O.ne Qu.arter), Cemre Panel Fke.sco— .Mouer.n.

be repeated too often ; the more it is carefully done, the better will be the polish. Every time the
agate is moved backwards it should be made to pass over a portion of its previous course, so cis to
prevent anj- mark or line at the edge. Lastly, if the surface is to remain white, take some water
which has been mixed with grated cocoanut, and lay it on the surface. Let it dry, and then rub it
down with a fine cloth folded into a |jad. If any colouring is desired, the same process is adopted
until the polishing with the agate is begun. This is onl>' done slightly. If any pattern is desired, it
is drawn on paper and pricked out. The paper is placed on the surface, and is dusted with very

Impressed Plaster IVork. 223

finely powdered charcoal tied up in a muslin bag. The charcoal passes through the perforations
and marks the plaster surface. The paints are mixed with water, and are painted on by hand while
the surface is still fresh and moist, hence the term fresco. Where a large surface has to be done,
it is necessary to employ several men to work at the same time, in order that the surface may be
all painted before it has time to dry ; or else the pattern must be so arranged that the connection
of one day's work with the work of the next will not be amiss. Immediately after the surface has
been painted, the colours are beaten in with the back of a small trowel, in such a manner that the
colour is not rubbed or mixed with the colour adjacent. As soon as it shows to the touch that the
colour has become incorporated with the plaster, the surface is painted over with water mi.xed with
grated cocoanut, and is then polished down with the agate.

" The following colours can be used in this process : — Lamp black ; red lead ; green (from a stone
known as Iiara patliar) ; }-ellow (from a stone called pila pathar) ; brown or chocolate. A little
glue is mixed with the two first colours, and gum only with the others. The colours used are
mostly earths or minerals, as others will not stand the action of the lime. Vegetable pigments
cannot be used for this mode of painting, even when mixed with mineral pigments, and of the
latter only those are available which resist the chemical action of lime. The lime in drying throws
out a kind of crystal surface which protects the colour and imparts a degree of clearness superior
to that of any work in tempera or size paint. The process, although apparently simple, requires
dexterity and certainty of hand, for the surface of the plaster is delicate, and the lime only imbibes
a certain quantity of additional moisture in the form of liquid colours, after which it loses its
crystallising qualit}', and the surface or a portion of it becomes rotten. It is only after the lime has
dried that such flaws are discovered, and the only remed\' is to cut away the defective portion, lay
on fresh plaster, and do the work over again. The colours become lighter after the plaster dries,
so allowance must be made for this. The advantages which this process possesses are clearness,
exhibiting the colours in a pure and bright state ; the surface is not dull and dry as in tempera or
size painting, nor glossy as in oil painting ; it can be easily seen from any point, and it is not injured
by exposure to the air ; it will stand washing, and can be cleaned with water without injurj-."*

Impressed Plaster Work. — Under the title of " Producing Ornamental Plastering or Stucco
Work," a patent was obtained in 1856 by Benjamin Ferry, architect, London. This invention
consists of indenting or impressing ornamental patterns on plaster surfaces as the work proceeds.
For this purpose ornamental pattern plates are formed with the pattern cut through them similar
to stencil plates. The plates are made of metal, their thickness depending on the depth of the
desired impression. The edge of the pattern is splayed so as not only to enter more freely into the
plaster, but also that the impressing plates may come from the impression produced without injury
to the impression plate in the first instance, but only to impress the plates into the surface, and then
after similarly impressing the other contiguous parts in like manner, to return to the parts first
impressed in order to deepen the impression. In pressing the ornamenting perforated plates into
the soft and plastic surfaces, the workmen should gi\e the plates a tremulous motion, b\- which not
only will the act of pressing the ornamenting plates into the soft .surfaces be facilitated, but the
plates will be found more readily to leave the impressions without injuring the sharpness of the edges
of the parts in relief It will be evident that in place of pressing the perforated plates into the
plastic surfaces after they have been laid on, the parts in relief ma)- be applied through the
perforated ornamenting plates, whilst the parts below are in a moist or plastic state, in which case
the parts in relief maj-, if desired, be of a different colour to the sunk parts.

* The foregoing is from the R.I.B.A. Journal, under the title of " Fresco Painting, as practised in Jeypore,
Rajputana," by Colonel S. S. Jacob, Engineer to the Jeypore State.

CH A VTMR \'I I I.
MODELL/NG.

The Prinxiples of Mohei.i.inc— Figure Mokei.linc;— Portraiture— Naturalistic and Conventional
Styles— The Modeller's Art— Modelling av i-/7T— Hand Work— Modeller's Shop -Modelling
Tooi^— Modelling Clay— Plastii.ina— Pate Plastique— Materials for Busts— Clay Modelling-
Ceiling AND Wall Decoration in Modelled Plaster— Method of Modelling /.vivrc^- Materials
FOR Modelled Plaster— Modelling in Cement— Wax Modelling— Modelling Wax, Beeswax-
Modelling IN Tow— Architectural Model Making.

The Principles of Modellinc. — Modelling is a very ancient art. According to some authors,
it was first a|)plicd to the ornamentation of the knobs on the covers for vases made man)- centuries
before the Christian era. Lucian describes Diogenes' tub as being one of these jars or vases with
knobs. The late Dr Schliemann considered that several of the modelled terra-cotta vases found In-
him at Troy were over ten thousand jears old. Such dates are of course open to discussion, but
Dr Flinders Petrie's discoveries conclusiveh- prove that the art of modelling jDlaster was well known
more than three thousand \-ears ago. In the Book of Kings we read that when Solomon built the
Temple he sent for Hiram of Txrc and his workers in brass, and that they cast two pillars of
molten brass, which were enriched with lilies and pomegranates. Homer mentions the Phcenicians
as being skilful artists ; but it was under Phidias, the Athenian, and the Attic School of the time
of Pericles, that art attained its highest ])oint ; and from this time, 460 B.C., to the capture of Corinth
by the Romans, sculpture bore off the palm. All these facts prove that modelling, with its
attendants, moulding and casting, was worked in great perfection in the early ages.

Modelling is the most simple and direct method of acquiring a due sense of form and
proportion. It is the best method of expressing form, as it deals with the third dimension, that
is, projection, as well as length and breadth. The art of drawing is the twin sister of modelling.

To the man who asjjires to be a good workman, foreman, modeller, or master-man, a knowledge
of drawing is most essential. It enables him to read a drawing, or to make one if required. F"or
the young shop-hand who is desirous of becoming a modeller, still harder study is required. A
knowledge of the various st\-les of architecture is highly important. Another desirable acquisition
is a thorough grounding in the anatomy of the human figure. The proper stud>- of the human
figure has not had the attention from the British workman that it deserves. Mr I^urgess, an
acknowledged authority on decorative art, says : " The third impediment to our progress is the
want of a more extended teaching of the figure. Up to very latelj- there seems to have been
great reluctance in almost every profession connected with the fine arts (except in those of
painting and sculpture) to teach pu])ils the human figure. So important, indeed, is this acquisition
of the power of drawing from the human figure, that there is scarcely a trade or profession where
the designer or artisan would not find it of the very greatest assistance ; and even in architecture,
which to a certain degree would seem indejjendent of it, except as an accessory, it is the onl)- way
of giving the pupil that power of judgment which is generally called good taste." Some one has

Figiiye Modelling.

said that the man who could draw a head could draw a leaf, but that it by no means followed that
a man who could draw a leaf could draw a head.

Plasterers should avail themselves of the many opportunities now to be had in the form of evening
classes at Art Schools and Technical Institutes (which most towns however small possess) to learn
freehand, modelling, perspective drawing, and geometry, which are great helps to all classes of
workmen. After the rudiments have been surmounted, the practice of drawing will become not
only a help, but a real and lasting pleasure. To be able to draw makes a man feel more confident
in his own abilities than the man who does such wonderful work at the bar or tap-room of the
public-house. Some men are apparently very clever in drawing with their finger in spilt beer
wonderful mouldings, telling how they were run and mitred, and how they ran diminished and
elliptic mouldings by the mile ; but on being put to the test, the abilities of these same clever men
diminish as fast as the beer drank overnight. I am glad to say this is the
exception, not the rule, though many of my readers will doubtless be able to
recall similar cases in their own districts.

Figure Modelling. — In the following remarks as to figure modelling,
it is assumed that the modeller has acquired command of the pencil, and is
able to express his ideas as to form by means of drawings. To acquire a
thorough knowledge, the student should copy from casts, from nature, or
the antique. He should also study anatomy. A ready knowledge of
figure form and anatomy enables one to know what to aim at and what
to avoid when modelling any of the innumerable attitudes that the human
figure can be made to assume. The study of anatomy quickens per-
ception and improves the memory, because, as Haydon said, " When the
mind is thoroughly informed of the means beneath the skin, the eye
instantly comprehends the hints above it."

The annexed illustration (Xo. 76) of the anatomical figure shows the
superficial muscles. A cast of the anatomical figure and a cast of Hercules
or of the fighting gladiator are excellent models to copy from. The bones
and muscles should be drawn and modelled in various positions. Their
sizes at different periods of life should also be drawn and measured. The
balance of the figure should be preser\ed. The centre of gravity will be
found in a \ertical line dropped from the little hollow at the top of the
breast-bone.

In well-proportioned figures the length of the body from foot to head is divisible into /i or 8
parts, each equal to a head. The widest part across the shoulders equals two heads in man, and
a head and a half in woman. The widest part across the hips equals a head and a half in man, and
two heads in woman. From shoulder to elbow equals one head and a quarter, and from elbow to
wrist one head and a quarter. From the sole of the foot to the knee, and from the knee to the
muscle at the side, and from this muscle to the shoulders, are about equal. If the arms be fully
extended, the distance from the tip of the middle finger of one hand to that of the other will be
equal to the height of the figure. The hand is equal in length to the foot, and the foot is about
equal to one-sixth of the figure. The female head is smaller than that of the male. The height
of the head is divisible into four equal parts, which are the space from the chin to the nose, the
nose to the e\e, the ej-e to the forehead, and from the forehead to the upper part of the head. The
width of the head across the eyes is equal to five eyes, and the space between the eyes equal to one.

No. 76. — .\NATOMIC.\L
FlGfRE.

226

I^lasfcn'iig-

-Plai)i and Decorative.

The bottom of the lower lip is slightly above the middle of the lowest division of the face, and the
lower lip has greater fulness than the upper. The width of the nostrils is about equal to the length
of an eye. and the width of the mouth to the length of an ej-e and a half. The ear is placed in the
back half of the head, and equals the length of the nose, with which it is on a level. The body is
proportionately longer in the child than in the adult. The head of the child is larger than in adults
compared with the rest of the bod)-. The head and face of the human figure expresses the general
character, the principal points of expression lying in the outer angles of the mouth and the inner
angles of the eyes and ejebrows.

The above rules are used bj- man)- artists of repute ; but although common, they are by no
means infallible, as the proportions var)- according to the age, sex, character, and race of the model.
Commence by copying from the best procurable models. For original subjects, copy from life

models. Drapery should be arranged on " la)- figures," and
these used as models to co]))- from. The subjoined illustration
(No. Jj) of the Venus of Milo, the original of which now stands
in the Louvre, is one of the finest productions of Greek art. This
shows the [perfection of the human form, and also shows a fine
example of draper)-.

A knowledge of mythology is an acquisition to a modeller,
especiall)- if he has to design. There is a story told of a man,
who, on being requested to enrich a panel with "Flora," innocently
inquired, "Flora who?" On being told that Flora was the god-
dess of flowers, he concluded that it was the figure of the florist's
wife that was wanted. A modeller should also be conversant
with allegorical subjects. A curious request was once made by
an embr)-o designer. He was desired to enrich a ke)-stone with
the head of Father Thames, on which he remarked that he did
not know the gentleman — could he get a likeness to copy from ?

PORTRAITUKK. — Portraiture is the art of producing a like-
ness of people and animals in any suitable material. To some it
ma)- appear that figure work and portraiture belong to the higher
art of sculpture, and are beyond the powers of a decorative
modeller ; but if one looks at the many excellent terra-cotta figure
panels, medallions, and plastic decorations that now- adorn many
mansions, it will be seen that modellers have made and are making
rapid strides in figure work. Mr G. Tinworth is a remarkable
instance of a successful modeller. He is the moving art spirit at Messrs Doulton's Potteries,
and his man)' beautiful bas-reliefs and statues are to be found in all parts of the world. The
importance of a knowledge of the human figure has already been pointed out, and as a knowledge
of portraiture is a necessar)- adjunct, careful stud)- and ample practice may bring to light
some embryo Flaxman or Michael Angelo. It is assumed that the modeller has mastered all the
rudiments of figure drawing and modelling before he attempts portraiture. When modelling a bust,
support the clay with a wooden upright and a cross piece, and tie a piece of leaden pipe at the top
end to allow the head to be bent or turned to any desired position. A bust support is shown on
page 233. The original and the cla)- model should be on the same plane, so that the modeller
will not have to look down to one and up to the other. The model can be raised or lowered as

No. 77. — Vem-s of Mn.o.

Naturalistic and Conventional Styles. 227

required by the aid of a modelling stool, as shown on page 233. Begin the modelling by building up
with clay, using the fingers freely, and occasionally a rough serrated tool to form the outline. After
the work is roughly blocked out, the calipers may be used for testing the actual measurements with
the original. If projections are too small, add more clay ; and if too great, work them down with a
serrated tool. Constantly \iew the original and the model from various points, and compare the
forms. View the back as well as the front and sides. This will enable many imperfections of contour
at the sides to be observed that are not perceptible from the front. Study well the proportion of
one part to another, for without a cultivated sense of proportion, artistic success will be difficult to
attain. At this stage the model may be left for a day to firm, but not dry. It should be covered
with a damp cloth or an oilskin to keep it plastic. Clean all tools, and put the surplus clay in the
clay box. On resuming the work, it is probable that previous undetected defects will be observed.
After correcting the defects and verifj-ing the proportion with the calipers, the details are next pro-
ceeded with. Avoid reproducing every crease of the skin, but define the features in detail, portra\Mng
every peculiarity and characteristic without exaggeration, and embod)' every effect or action which
constitutes the expression. Great skill is required in finishing the skin so as not to lose the drawing
of the surface. The hair should be broadly massed, using but few thin lines. The drapery is left
less smooth than the skin, but more so than the hair. Various \\a.ys are used for producing
texture surfaces. Coarse line's may be obliterated by using a wet cloth or sponge, and by pressing
the thumb in parts. The same tool must not be used for both flesh and drapery. Texture is to
a model what the marks of the brush are to a painting. In the drapery, great attention must be
paid to the folds. Ever)- fold necessitates a ridge and a groove. Parallel folds should be avoided ;
curved ones have breaks, which give variety. Triangular forms in drapery are always pleasing, so
are key folds, as formed when two folds meet and unite in one ridge. As a rule, flat drapery is more
effective than round folds. A good model for draper)- is obtained by the use of wet linen or by dry
and soft woollen cloth. Drapery for the full figure is a great test of the modeller's power, and he
should first copy from the antique, and then from nature. It has been aptl)- said that a clay model
is in a transitory state, in plaster it is life, and in marble it becomes immortal.

Naturalistic and Convextioxal Styles. — In decorative or ornamental art there are
two schools which strive for pre-eminence, viz., the naturalistic and the conventional. Each has
its admirers and students. An eminent authority on decorative art sa)-s : " True ornament does
not consist in the mere imitation of natural objects, but rather in the adaptation of their peculiar
beauties of form and colour to decorative purposes, controlled by the nature of the material to be
decorated, the laws of art and the necessities of manufacturing, and civilised tastes." Another writer
of great discrimination says : " From the labours of ornamentists united to the common search
after novelty at any sacrifice of true taste, for which manufacturers are so constantly urging, there
has arisen a new species of ornament of the most objectionable kind, which it is desirable at once
to deprecate, on account of its complete departure from just and true principles. This may be
called the natural, or merely imitative style, and is .seen in its worst development in some of the
articles of form. Thus we have metal imitations of plants and flowers, with an attempt to make
them a strict resemblance of a thing, rather than to imitate it. This is the case with fine art also.
In its highest effort mere imitation is an error and an impertinence, and true ornamental art is even
more opposed to the merely imitative treatment now so largely adopted. Let an)- one examine a
floral or foliated ornament produced in metal b)- electrotyping the natural object, whereby ever)-
venation and striation of the plant is reproduced, and compare it with a well and simply modelled
treatment, where onl)- the general features of the form are given, and all the minutest details

22S Pi'as/criiig — JVaiii ami Decorative.

purposely omitted, and if this latter has been done with a true sense of the characteristics of the
plant, the meanness and littleness of the one mode will be ])erfectl}' evident compared with the
larger manner of the other." An im|Jortant point in designing and modelling is unit\and appropri-
ateness of the design. It is the fitness or suitability for a given place that makes the whole an
appropriate decoration.

TllK Modkllkk'.s Art. — The thanks of all interested in plastic art are due to those architects
who insist on having their designs specially modelled, instead of choosing from the (in some cases)
poor selection of the plasterer's stock of models. I have seen ornaments of various styles introduced
into one cornice, but happily such cases are rare. Another detriment to the employment of
modellers, and consequently to the art, is that the master plasterer is allowed to retain the originals,
not for reference, but for use again and again, and often witliout regard to style, height of room,
form of the members of the cornice, &c., but simply because it happens to be near the size of the
space to be enriched. It is not fair to the proprietor who builds a mansion, or to the architect who
has caused special designs to be modelled, to afterwards find them reproduced in some public-house,
or in a common speculative, jerry-built edifice. Some architects insert a jjroviso in their specifica-
tions that the originals shall be broken up after the completion of the job, or bind the plasterer
down not to remould the originals for further use. Sometimes architects and surveyors, when
selecting ornaments, or choosing models in a plasterer's or modeller's shop, judge them as they
appear lying on a bench, without thinking of the height or jxxsition they are intended to occujjy,
the amount of light that will bear u])on them, or how they will harmonise with the other enrichments
and members of the cornice. About eighteen >'ears ago an addition was built to the National
Galler}-, where I was employed on the modelling. Mr E. M. Barry, R.A., the eminent architect, had
about 6 feet of the cornice in each of the \arious galleries run in its pr<j[jer position, and the \arious
enrichments fixed. A portion of the .scaffold was cleared away in order that the effect of the cornice
might be seen from the floor. The late Sir Digb)' W'j-att adopted the same plan before giving the
modeller a final assurance of satisfaction. Another evil is the somewhat dishonest practice, either on
the part of the general contractor or the master pla.sterer, who, to save the expense of modelling,
resort to what is generally called " cobbling " — that is, taking a bit of this, a bit of that, a bit of .some-
thing el.se, no matter what, so that it fills up the space, and getting a shop-hand to squeeze or mould
and cast the various parts of the enrichments, and put the lot together, making up a leaf here and
a stem there to complete the design. The works of different modellers are often taken anrl nii.xed
together, and before the various parts are joined, the design looks more like a puzzle than a decorative
ornament. I have said this is done to save expense, but it is very questionable if it does so, and it
is probably a more costly proce.ss. Some employers think if a cheap man can make .something like
the required enrichment, lie will effect a saving ; but if he were to reckon his own time and that of
the shopman looking for the different originals rciiuired, and squeezing or moulding and casting,
then cutting and filling, and the plaster wasted, I think the balance of cost would be in favour of
employing a good modeller, and also that the work when fini.shed would be far more satisfactory
from an artistic as well as from a pecuniary point of view.

Another plan adopted in some shops, especially where there is a stock of old metal, wood, or
plaster piece moulds, is to choose a mould having a scroll, swag, leaf, head, &c., or what may be
required to make up a given design, and to fill in the jjarts required with paste composition. The
compo casts are then mounted on a ground, and being of a more elastic nature than a jjjaster
cast they lend more freedom for bending the stems, scrolls, &c., to the required cur\es. The colour
of the compo is nearly the same as clay, therefore the work when submitted for the architect's

The Modeller s Art. 229

approval appears as if expressly modelled. The compo being fixed with soft compo or needle
points, can easily be altered as required.

Many modellers have begun as shop-hands, and some have worked on the scaffold. In my
plastic experience, after three years in the shop, casting, moulding, and modelling, I have known
what it is to use the " broadsword " (big laying trowel), do a week's stretch of first-coating, floating,
run mouldings, and fix wet ornaments on a cold raw morning, but I have found my building experi-
ence of great advantage in subsequent shop-work and modelling. If all men are not able to be
"sons of clay," there is still a pleasure in knowing how it is done, and in being able to tell when it is
done well. A knowledge of shop-work is very useful to a scaffold or building plasterer, more
especially to a man employed on ornamental work. It enables him to fix ornament with neatness,
and work up the mitres of enrichments with taste and despatch. The father of John Flaxman,
the world-renowned sculptor, was a modeller and plasterer. Flaxman in his early days designed
and modelled for Wedgwood. His first model in wax was produced at the Royal Academy in 1 770.

An artist is a workman. The converse should also hold good ; but how seldom does it happen
that the workman is an artist ? A good man approaches his work with true artistic feeling. To
do it badly or roughly inspires him with a sense of shame, such as a true man feels when he has
unwittingly been drawn into or mixed up with a mean or dishonourable action. The whole
tendency of the age is towards gain, veneer, and underselling, which is not favourable to honest
work or workmen, or to the development of artistic feeling. It is only when a man begins to put
his heart in his work that he has pleasure in doing it, and produces satisfactory results. Fiammingo
was elevated by the production of his beautiful models. Benvenuto Cellini took a pride in his
gorgeous vases. Palissy, the potter, delighted in his rare productions. Flaxman felt a glow of
satisfaction over his superb and graceful sculptures. Luca della Robbia revelled over his exquisite
wax, cla\-, and plaster models, and Wedgwood was proud of the famous ware that bears his name.
And so with all other great art workmen, because of the great beauty, the openings for form and
taste, the exercise of fancy, and the expression of feeling in all their works.

Modelling "ix .situ." — Modelling work done in situ affords a happy medium to enable the
architect to relie\e the plainness of the structure (internal or external), without waiting for the
sometimes slow process of moulding, casting, and fixing, in addition to the actual modelling.
Modelling in situ can be done on stone, brick, wood, or iron work. The tenacity of the modern
cements enables the work to be done on an)' surface, however smooth. The materials can be
coloured, or afterwards painted to match or harmonise with any colour. There is always the
adxantage of knowing that /;/ situ work will not be reproduced ad libitum by jerry-builders, who
often obtain copies of the models at unfair prices and by unjust means. Work done in situ enables
the modeller to use his eye and reason. He can exercise both to judge the effect in actual position.
He can also get better effects with less ornamental detail. This method of formation produces
more artistic work, and a greater \ariety of design. With a little practice with the material, it is
just as easy to model in cement or stucco as in claj-, and the result is absolutely your own work.
It is as easy for a modeller to do work in situ as it is for a carver— in fact, the modeller has the
advantage that he can add as well as subtract. This niethod of modelling would give an impetus
to the art and craft. Manj- portions of work that are generally done in the shop might with
advantage be done in situ. This would avoid repetition. Small enrichments which are essentially
repetitive, because they form an outline of a member, may be modelled, moulded, cast, and fixed, and
in some instances be repeated. The evil and want of taste is in repeating the portions which were
speciall}- designed for one particular place and purpose, and using them inappropriately. W hen

230 Plastering — Plaiii and Decorative.

modellers and plasterers throw off their present apathy, and stud)- their craft more carefully and
artisticall)-, there will doubtless be a large future for modelling in situ.

Hand W'dkk. — The origin of plaster work is lost in antiquity. It is known to have been
largely used in ancient Greece, in temples such as that of Apollo at Delos, and in the ancient
Parthenon. The ancient decorative plaster work unearthed in Rome, Pompeii, and the Italo-Greek
tombs of Magna Gra;cia, show how extensively it was used, and to what perfection its decorative
uses had attained. .All this work is exclusively hand-modelled. Professor Aitchison, .A.R..\., has
.said that " the most beautiful ornamental plastering he has ever seen was in a vaulted chamber of
Hadrian's \'illa, . . . and it appeared to have been entirelj' modelled by hand. . . . Such
work had the charm of variety which cast plaster never possessed." It is generally believed that the
ancient method of executing decorative plaster work was that of modelling entirely in the .soft
plaster ;// situ. It is more probable that the general method was a combination of cast work (and
possibly stamped work) with hand work. The main ornament was cast and fixed, while the minor
foliage were subsequently modelled. The leading ornament may also have been stamped in situ,
and the subordinate sprays and leaves worked up by hand. Running patterns were made by press-
ing moulds or stamps on the stuff while soft to form the general outlines. The work was then
undercut and finished by hand. Plasterers of old used wood, lead, and resin moulds.

Hand work is simply modelling direct with stucco, cement, or plaster. The work may be done
/';/ situ or on slabs, and then fixed. The art of hand work in the past had a wider range than at
present, when all the ornamental work was done by hand, e.xecuted in the freest manner in soft
plaster, and with excellent effect on the walls and ceilings of which they form the decoration.s.
These examples of the skill of the worker in plaster may well, in their happy and free effect, bear
witness to the easj- and natural appearance of which this mode of working is capable. It is a
regrettable fact that this beautiful mode of artistic decoration has fallen into disuse ; but architectural
fashion, like history, repeats itself, and when a higher sense of duty in relation to art arises among those
able to encourage this charming plastic art, it will be revived, and become permanent and pleasing.
The numerous foreign examples mentioned by Mr G. T. Robinson, and the photographs of ancient
works, abundantly prove its durability. The illustrations in this work will show that the old hand
work was artistic as well as durable. The question of cost is greatly in favour of hand work.
Materials are cheap, and it is quicker than modelling in clay, and then moulding, ca.sting, and fixing
the casts. It is, in fact, as easy to model in stucco, cement, or plaster, as in clay, and the work has
all the merits of originals, not dull cast work repeated ad nauseam, but each separate part instinct
with fresh life and vigour. Even if hand work does cost somewhat more than cast work, the client
has the satisfaction of knowing that it is his own copyright, and that he will not be anno)-ed by
finding it repeated in jerry buildings. Casts of new modelled work are sometimes obtained by
taskmasters from some peccant plasterer in want of a job, and who has been at work where the
casts were first used. Happily such instances are rare.

Among the few works done by hand in the present day may be mentioned the Swan Hotel,
Chelsea, and Mr Holt's house, and the works of Messrs Ernest George & Peto. Another modern
example of stamped and hand work is Mr Collcut's quaintly designed facade in Fleet Street.
Mr Walter Crane is an artistic exponent of hand-worked plastic art. Mr G. T. Robinson executed
a large hunting scene in stucco on the gables of a building at Cowdray, near Midhurst, for Lord
Egmont. I have had some little experience in plastic hand work, notably at the Baynard Castle
Hotel, Queen Victoria Street, London, built 1874. The whole of the front, with the exception of
some small coats of arms, about 9 inches by 5 inches, was worked up by hand in situ. The materials

Modelling in Situ.

231

used were Portland cement, lime putty, and sand, in the proportions of 5 parts of cement, 2 parts of
putty, and 2 parts of sand. These were mixed together, and then coloured by addinfj j'ellow ochre
and Indian red to imitate terra-cotta. A curious fact in relation to this part of the work is that
it was actuall}' sketched and described by a leading technical journal as terra-cotta. The building
was designed by Mr Almond, architect, and the drawings for the ornamental work were made
by E. Robbins from old engravings. A portion of this work is shown on the annexed illustration
(No. 78). The on!)- difficulty in working this rough material was to keep the forms somewhat

No. 78.— E.KTERioR Ornamentation in Portland Cemf.nt, Modelled in silii by W. Millar, 1S74.

Baynard Castle Hotel, London.

crude to be in accordance with the originals. In an upper panel there is a perspective view of the
original Baynard Castle done on a cement ground h inch thick. I am doubtful as to the durability
of this work, as the lime used in combination with the Portland cement was quite new, in fact, hot
when used. The new lime may cause excessive expansion or blo\\ing in the cement, and lead to
fractures, in the future. In my opinion the brick work was insufficiently keyed to retain the orna-
mentation, which may affect its stability. Being only engaged to do the modelling, I had no voice
in the selection of the materials ; this and the method of ke>-ing the surface was under the sole

-J-

Plastcriiig — Plain (tnd Decorative.

direction of E. Robbins, the foreman plasterer. I am pleased to state that several <.f the plasterers
who were employed running the moulding also assisted in laying on the stuff and cutting out
various parts of the decorated surface, and also displayed an apt ability in modelling some of the
minor work, among whom may be mentioned J. W'ilson and O. Cullen. Mr G. Vulliamy, the city
architect, had the supervision of the whole building. E.xcellent examples of hand work are to be
seen at the Grafton Galleries. A portion of this work is shown on the annexed illustration (No.
79). This shows a frieze about 5 feet high, modelled in situ by C. Giddings for Gilbert Seale in
1892, Messrs Wimpcris & Arber being the architects. A stumbling-block in the way of this art
becoming more popular is due to the want of a little humility on the part of the modellers in donning
a blouse, and working on the scaffold. The artists of old, men of genius and talent, who worked in
plastic art, were not afraid or ashamed of their work or their blouse. The greatest artists of the
present day wear them. Sir Frederick Leighton and other English artists wear a common painter's
blouse when engaged on decorative work, and absolutely do the work with their own hands.
Therefore labour of this kind really ennobles a man, and his blouse is a garb of honour to him.

No. 79.— Krie/.e Modelled in silu. Grai-ton Galleries, London, 1S92.

Modelling Snor. — The modelling shop should be high, and lighted from the north or east.
A roof light falling at an angle of 45' is best. If this is not procurable, have a large side light.
When gas is used, it should be on a movable upright, with a long flexible rubber pipe. A modelling
stand is required. This is about 3 feet 6 inches high, and has a movable top, which revolves on
a pin. Some are made with fixed tops, and a turnbat laid on the top, so that the model can be
turned round as required. Another kind, chiefly used for modelling busts, is made with a screw
running up inside the stand, so that it can be elevated or lowered at will, as shown in illustration
No. 80. Illustration No. 81 shows a bust support, being the method of forming internal support as
used when modelling busts. The upright piece in the form of a cross is fixed to the lower or
modelling board. A piece of flexible metal tubing is tied on to the top of the upright. The
flexible tubing allows the head of the bust to be moved if required to obtain any desired pose.
The bust support is placed on the modelling stool, and the whole is then raised and lowered as
required. Turnbats are made with two round boards, each about i inch thick, and from 12 to 16
inches diameter. The top revolves on a pin which is fi.xed in the lower board ; it should turn
smoothly on metal rollers let in near the edge, or between two zinc plates well greased.

Modelling Tools.

'-II

Modelling boards, and slate slabs for modelling flat surfaces, are necessary ; also concrete
clay tanks to keep the clay clean and moist. Pieces of unbleached calico are required for keeping
clay models moist. A looking-glass is useful to facilitate the comparison of the effect of the work.
It is held up over the work, and the effect can be seen by looking in the glass. An easel for
supporting modelling and drawing boards is useful. Casts of heads and the human figure from
the antique and modern sculptors, such as Flaxman, should be hung up for reference purposes.
There should also be choice bits of fruit, flowers, and foliage, from the works of eminent masters
of the art of modelling, and also casts from nature. The work of modellers is often subjected to
the pert criticism of certain classes of visitors. The following sentence which I have seen some-
where in a corner of the Ouartier Latin, Paris, called the " Artists' Quarter," might with advantage
be written o\er the door of the modelling shops — " Carpere facilius est quam imitare" (It is easier
to criticise than imitate).

Modelling Tools. — Modelling tools are usually made of bo.\wood. Pear-tree and bone

Xo. So. — MoDELi.iNX, Stool.

No. Si.— Bust Support.

are also employed. They vary in length from 7 to 9 inches. Some are plain on edge, and others
are serrated, j-et others have the ends shaped like finger points. Some of the most useful forms are
exhibited in the annexed illustration (No. 82). The best tools for modelling are those made bj^ the
user. Good tools for small work are made from the handles of old tooth brushes. I have seen
Tom Garland (who thirt}- years ago was called the Father of Modellers) produce ver%- effective
work with one or two sticks from a halfpennj- bundle of wood ; but I do not recommend novices
to tr\- this form of tool. Another useful and effective tool for modelling is the wire tool. This is
made out of a thick brass or copper wire, flattened and bent to the desired shape. It is then fastened
on a boxwood handle with brass wire. Wire tools are made in various shapes and sizes. The
principal forms are as exhibited on the annexed illustration (Xo. 83).

Steel tools are occasionall}- used for clay modelling. They are, however, more adapted for
modelling in plaster and tow, also for cleaning up plaster models. Some modellers use brass tools
for modelling, but no material is so well adapted for this purpose as the wood and wire tools herein

234

Plastering — Plain and Decorative.

described. Do not forget that nature provides those that are most efficient and principally used,
viz., the fingers.

Compasses and calipers are also required. A basin for clean water and a sponge should
be at hand for keepini; the fingers and the tools clean. A plumb-bob and a foot-rule will be found
useful. Adjustable calipers, as shown on illustration No. 84, are useful for enlarging and reducing
models. They can be made of hardwood or steel. They are made with a movable centre, so
that the proportion between the points at the minor end c can be altered as regards the major
end b.

Some modellers require fewer tools than others. In connection with this I ma>- mention that
during the Belt and Lawes furore, I was engaged giving entertainments at the Theatre Royal,
Bradford, and other places, modelling busts of the Prince of Wales, and sometimes men selected
from the audience, a la " Belt." For this purpose I only used a wire clay cutter, one modelling tool,
and the fingers and thumbs, occasionally using both hands so as to balance the most prominent

parts on each side more
readily. A modelling stool
was placed on the stage, and
two or three blocks of clay
placed on the top of the stool,
and then I proceeded with the
modelling of the bust. The
wire clay cutter was used for
reducing the clay to the pro-
file, and the modelling tool
and fingers for the details.

Modp:lling Clav. —
Clay is generally used for
modelling. It is easily mani-
pulated and kept moist with
moderate attention. It can
be procured in balls or in
bulk ready for use at most
pottery works. If kept clean
and free from oil and waste plaster, it can be used o\er and o\er again for different models.
The more it is beaten and tempered, the freer it works. New clay is spongy, and is liable to
shrink and crack. It should not be allowed to dry, or it will become hard, and involve much
labour to make it fit for use again. Some sculptors prefer clay mi.xed with a little fine sand
to give it more grip. Modelling clay is chiefly got at Newton Abbot, Devonshire. There are
seventy balls to a ton.

Plastili\.-\. — Several methods have been tried to render clay indefinitely moist and plastic.
Oil, turpentine, vaseline, and glycerine have been used as substitutes for part of the water. Oil
clay does not work so freely as water clay. " Plastilina" is a modelling material invented by Senor
Giudici, of Genoa. It looks and works like clay, but has a strong odour. It will not leave the
hands without using soda or Hudson's soap in cold water, but it will dissolve with ordinary soap
in hot water. It will not hurt the skin, but care must be taken to prevent its coming in contact
with the eyes.

No. 82. — Wood Modelling Tools.

Clay Modelling.

235

" Pate Plastique " is another modelling material which is used by Parisian modellers. It
is the same as modelling wax, and is made in various colours. It works freely and clean to the
fingers. Plaster, gauged with glue water to retard the setting, is prepared by some sculptors for
large work. The groups in front of the Trocadero, in Paris, by Falgniere ; also the Quadriga,
temporarily placed on the Arc de Triomphe, were modelled in this material. Mr Watts modelled
his great statue of Hugh Lupus, for Eaton Hall, in plaster. A small sketch model in clay or wax
to scale is first made, then
the large framework is made
on wood or iron supports.
On this a foundation of
lath-work or canvas dipped
in plaster is formed. The
whole is then covered with
a rough coat of plaster.
The work is then modelled
in the glue-gauged plaster,
and a pleasing finish is ob-
tained by using flat brushes.

:\I A T E R I A L S FOR

Busts. — Superfine plaster
is the usual material for
_easting busts and medal-
lions. Superfine Parian
cement is an excellent
material for casting busts.

It is stronger and more marble-like than plaster. Of course it requires greater care and attention
than plaster when casting, but this is amply repaid by the results. I modelled a bust of the Prince
of Wales from photographs, and reproduced it in Parian cement. The bust was exhibited in the
Bradford Technical School Exhibition in 1882, and excited some curiosity among the craft. As
regards the material, it had the touch and appearance of real statuary marble. Plaster casts,
coloured to imitate terra-cotta, look better and last longer than white plaster casts. Yellow ochre

and purple brown are mi.xed with the gauging water to
obtain the desired terra-cotta tints. A marble appear-
ance is obtained by gauging ground glass with fine
plaster. This gives the lustre and sparkle of real
marble. For other materials, see " Recipes."

Clay Modelling. — Clay modelling is a .seductive
art. \\'hen once begun, it is not easily left off. It
educates the hand and the eye, and greatly quickens the
perception. Man can express his ideas better with clay than with chalk and pencil. But for artistic
purposes it is useless to attempt modelling without a knowledge of drawing. Modelling may be
described as raised drawing, and to those who can draw the work will be easier and come more
naturally. Having acquired freedom with the pencil, the novice may begin with clay. Some simple
leaf may be copied ; first the same size, and then a size and a half larger. Keep on copying to give
confidence, freedom, and a grip of the clay, using nature's tools, the fingers, to add the clay when

No. 83. — Wire Modelling Tools.

No. 84. — Adjustable Calipers.

236 Plastcri)ig — Plain and Decorative.

required. Never begin to put in detail or finish until the whole is blocked out, and proved correct in
size and proportion. Fine details and smooth finish are of secondary consideration. When the eye
is unable to judge and correct size, contour, and proportion, use calipers and compasses, but use them
as little as possible in order to train the eye. Practice alone will enable the student to detect and
correct errors and irregularities in lines, contours, and points. W'hcn errors are detected, they must be
effaced in a bold and decisive manner. If the errors are numerous, the work should be begun over
again, avoiding the previous errors. This is better than correcting a mass of mistakes. The work
should be gone o\cr again and again, doing a little here and a little there, and stepping back to judge
the effect from different positions. Constantly viewing the work too near or from one point accustoms
the eye to defects. The first portions of the work must be (in^vcd with the calipers, and the effect
with a mirror. Many defects will be seen when reversed in the glass. Wiien the work is correctly
blocked out, the finishing ma)- be begun, but no attempt should be made to finish one part to the
neglect of others. Too much detail or o\'erfinish should not be put into the work. A sketch
model has greater charms than a smooth surface full of littleness. The rough zigzag strokes which
occur in unfinished sketches, whether drawn or modelled, have an artistic effect. When a high
finish is attempted, the work looks mechanical and hard. Fine finished surfaces may be used for
small repeated enrichments, or where fine painting or gilding has to be applied, especiall)- if the
gilding is to be burnished. Plaster having a fine natural te.xture, the casts gradually assume a
smoother surface than the rough original. This is also caused b}- the surface of the mould wearing
smooth or blunt by repeated friction when casting. The reverse also occurs if the moulding and
casting is improperly done, and the moulds and the casts become rougher with every successive
cast. The opposite effects of fine finish and texture will be seen b)- taking a cast from a finel}- carved
stone. Although the plaster cast ma_\- have a smooth surface, the general details will look coarse
and the effects toned down when ct^npared with the stone. The novice should never be too
ambitious, or attempt large or important subjects, before ha\ing full\- mastered minor and simjile
ones, and the rudiments of the art. Modelling, like the art of music, cannot be learned until the
.scales have been mastered and committed to memorj-.

When ornamentation is near and subject to close inspection every part of the work should be
fully expressed and well finished, but when it is exalted the details should be slightly touched, as it
is sufficient if the general form be distinct and the principal features well developed. A few rough
strokes from a skilful hand are much more effectual than the most elaborate finishing of an artless
imitator. Smoothing and neatly rounding off the parts destroy rather than produce effect. It is
necessary that craftsmen should study the ancient styles, not for reproduction, but for the knowledge
to be gained in a technical waj'. In Schools of .Art the students are frequentlj' required to go
through a course of modelling casts of the antique. The casts are generally taken from marble,
stone, and wood models by past masters of the art. Casts from nature, such as fruit, flowers, leaves,
&c., are also used for models to copy from. Plate XLII. depicts two panels, and illustration No.
85 a pilaster panel from Venice in the Italian Renaissance style ; all are excellent subjects to draw
and model.

Copj-ing from models should be sparingly used, or the modeller may sink to the level of a mere
copyist. When working from a drawing or a photograph, the modeller must exert all his ingenuity
to interpret it. Obviously a model is best for a novice to copy from until he has acquired the
power of form, then a drawing can be taken as a subject to increase his powers of form, and
command of the materials and tools. The young aspirant should examine and study all old
examples of modelling remarkable for their styles and execution.

Modelling.

237

When the modellin<j of foliage has been acquired, parts of the
human figure may be begun, copying an eye, nose, hand, or foot.
The work should be copied repeatedly, only on different sizes or scales.
Having mastered these details, complete heads and then figures ma\-
be tried, and then original designs. The proportions of the human
figure have already been given. Xo man can be thought or called a
modeller unless he can model the human figure. It will be seen
by the numerous examples of ancient and modern works illustrated
herein that the human figure (either whole or in part) is frequentl}-
employed in decoration. From antique times up to the present da>
half figures have been favourite subjects as caryates, persians, and as
starting for ornaments, such as brackets, trus.ses, pilasters, &c. Two
examples of these (male and female) are given as illustrations
Xos. 86 and 87. The subject and main details for original decorative
designs should be well thought out and committed to paper before
commencing the modelling. Minor details and effects may be pro-
ceeded with while the modelling is in progress. For large subjects the
cartoon is laid over the ground, and the main lines and points set out b\'
passing over the outline with a blunt iron st}-lus, pressing the paper so as
to leave a line sufficient as a guide. Frequently instead of the stylus
the pounce bag is used, and the pricked design is pounced in red or
black, as is used for sgraffitto, and by the Moors for their pin-point
stucco, as guides for cutting out the surface work. Even the impatient
genius of Michael Angelo condescended to the pouncing process, and
some of Raphael's cartoons that have been preserved are covered with
pin-holes. If a plaster ground is used, the surface should be brushed
with a thin solution of shellac. This hardens the surface, and gives
a good grip for the clay. Clay used on a new and damp plaster ground
is apt to peel, and if dry it renders the clay stiff and unworkable.
The pouncing process is useful for right and left, or reversed patterns.
These marks are aids for size and jointing purposes, and they save
the too frequent use of the compasses. When the model is finished,
the marks are easily stopped with claj' or trimmed off the face of the
mould. In some instances the work is modelled on a clay ground,
but this does not afford a true background, and as it is difficult to joint,
it should only be used where there is little or no background, or where
the design is self-contained. Plaster without doubt makes the best
ground for modelling, running, or repeated designs, such as soffits,
friezes, &c., because it can be cut with a band or key saw, or twisted
wire, at any desired place, and when the ends are reversed, this will
form a true joint. Joints should be made at the sides of main stems
or bands, or where they will be easy to stop, and least observable.
They should on no account be made in the centre of large parts, such
as main leaves, fruit, or flowers, but they may on the bed of such
parts, the leaves, &c., being moulded separately, and planted so as to

^^^UJIM.Stl^

V ^\

• .

N\'. S5. -I'll.ASlER I'ANEL
FROM VeNKK.

23S

Plastering — Plain ami Decorative.

No. 86.— Truss.

iMt,

,Jb<

cover the joints. When modelling cornice enrichments, a sufficient length of the cornice should be
run to model the various enrichments on their true beds. This also enables the harmonj- of all ilu-
enrichments and the plain members to be judged as a whole. The enrichments should harmonise
with each other. This is effected b\- setting them out so that the centre or most prominent part
of one will come over the centre of the one immediatelj- beneath it, and so on with all the others.

The largest enrichment should rcgu-

late the smaller ones. Nothing is more

offensive to architectural taste than to

see the centre of an cg^^ placed o\er

the edge of a dentil, or the main or

centre stem of a leaf enrichment placed

over the side band of an egg. Knrich-

ments for panel work, or where there

are numerous short lengths and mitres,

should be so arranged that they will

form a fair mitre. Nothing is more

unworkmanlike than a clumsy mitre —

for instance, to see the dart mitre w ith

a part of the Q%g or the main stem

of a running soffit spring from a small

tendril, or the half of a leaf butt against

the i^lain members. Good mitres and

the harmonisingof enrichments greatl}-

depend upon the plasterer who makes

the cast work, and unless he careful!}-

sets the work out before fi.xing, the

whole, however carefully modelled, will

be spoilt. About thirty years ago I

was at work in the modelling and

moulding shops of William Cubitt,

the well-known London builder. I

noticed how carefully all the plaster

cement, carton-picrre composition, and

terra-cotta work was done. Nothing

was left to chance, every part being

done by the best system, and under

intelligent supervision, Mr G. Baldwin

being the shop foreman and Mr

Willoughby the walking foreman. Mr

Baldwin introduced many improve-
ments in the wa\- of working the various parts in plaster work. Mr Willoughb}- was one of the old
school of plasterers ; and like .some of the old journejmen then at work, he had a leaning towards
tall hats, stiff stand-up collars, stock neckties, moleskin trousers, and blue coats with brass buttons.
He was brimful of plastic knowledge. On his retirement through age he was rewarded with a
handsome pension. All sub-foremen and old hands in this firm were pensioned when age over-

No. 87. — Ornamental
Pilaster.

The Use of Plaster for Interior Decoration. 239

took them. The firm also kept a night school on the works for their apprentices, and a sick
club for their men. One naturally inquires where such men and firms are now to be found. I
cannot say, but would like to .see similar good feelings revived between employers and employees.
During the three years I was at work with this firm there were on an average five modellers,
about sixty shop-hands, and two hundred scaffold plasterers regularly engaged throughout the
year. It is very rare to find a plasterer's and modeller's shop in a builder's establishment affording
such opportunities for acquiring a practical knowledge of the many and varied parts of plastering
as was then to be found in Cubitt's. Here modelling, and model making in plaster, for plaster,
cement, wood, stone, marble, metal, and terra-cotta works were constantly to be .seen. Moulding in
plaster, wa.x, and sulphur, also casting in plaster, cement, concrete, carton picrre, papier mache,
composition, and terra-cotta, also scagliola work, were in daily progress. It was the custom at Cubitt's
to model mitres for all enrichments, and two lengths of the design for soffits, guilloches, and friezes,
one as a shrinker and the other as a stretcher, to enable the pattern to come to a true mitre. Enrich-
ments for short breaks or returns were set out on a bench, so as to get the external, internal, and butt
mitres symmetrical. The mitres were then worked in plaster by hand, so that the main stems and scrolls
should flow freely and naturally, and that the bands should finish in graceful forms. The casts were then
numbered in rotation, and sent to the job ready for fixing. Large modelled surfaces intended for high
positions should not be waste moulded and cleaned up. They should be moulded direct from the clay,
so that the casts will bear the impress of the artist's individuality,and the artistic soft feeling which, when
combined with breadth, light, and shade, gives the true effect and harmony of architectural decoration.
With regard to the use and treatment of ornamental plaster work for internal decoration,
there is no material that has such strong claims. Its unique fire-resisting, sanitary, and durable
qualities render it indispensable at the present time as it has been in the past. It not merely
answers very many technical necessities, but tends more and more to satisfy the aesthetic sentiment
by a graceful de\elopment of form in decoration; and an immense number of plastic objects exhibit-
ing an artistic treatment in many cases of great excellence are produced in it. A large majority
of them, however, are pervaded by one grave fault, a superabundance of ornament, which, covering
too large a surface in proportion to the plainer parts, disturbs the impression of quiet repose and
artistic harmony. The effect of the most ornamental details, and even of their most graceful
arrangement, will be weakened and disturbed if they are not separated by plain surfaces of some
extent, simple profiles, and great bold lines, offering some repose to the eye, and relieving the
principal features of the work, all of which must be designed with careful attention to the proportions
of the object itself, and the place it is to occupy. The first principle of decorative ornament is that
the spectator should have a full and distinct \ie\v of it as soon as he is sufficientlj- near to compre-
hend the whole at one glance. It must be considered a great fault if, at that distance, the orna-
ments which take up so much of the whole space should present to the eye an indistinct chaos of
scrolls, tendrils, and foliage, and if no clear idea of the course of the lines and the distribution of
the parts is to be obtained except at a very close proximitj-. An incorrect application of ornament
of this nature may often produce an effect the very opposite to that of the model, especiall\- in deep
undercut or perforated ornaments, in which the lighter or darker colours of the intervening parts
come into consideration. An especial fault of deep undercut or perforated ornaments in larger
objects is their conception and execution. Their distribution is too monotonous ; they are without
any principal features or dominant lines. The background, though visible, is little attended to, so
that they frequently produce the effect of a rough-grained surface instead of imparting to it a life
and spirit of its own by beautiful and appropriate decoration. What has been said above refers

240 Plastering — Plain and Decorative.

chiefly to the contour or profile, but it may be equall\- applied to those ornamental parts which are
in relief. With manj- objects in cast work a flat relief is often necessary, so that with these a
diaper or a repeated jjattern arrantjement of the ornaments will be the most suitable, rei^'ard being
had to the above observations on the distribution of the spaces and the rhjthmical arrangement of
the main lines. A great number of objects in virtue of their destination not only allow the use of
high and bold relief, but it is even absolute!)- necessar>- from their position in ojjen and vast spaces.
But in the latter case, as with the flat surfaces, the alternation of greater lines, the effective distribu-
tion of light and shade must be carefull)- attended to, or the delicate effect of the relief will be
diminished if not destroyed.

Ckiling .vnd \V.\ll Decor.\tion in Modelled Plaster. — Plaster work is the natural
covering of walls and ceilings. It is not governed by coursing or jointing as in stone or brick, and
there is no piecing or framing as in wood. The full face of plaster presents a breadth of field
such as no other building material possesses. What better surface can be obtained for archi-
tectural and decorative effects? The broad surfaces on ceilings, coves, and walls suggest and invite
decoration, and no better material can be used for this purpose than a material similar to that
used for forming the straight and smooth surface which covers the rough walls and the open wood
work of the ceiling. Ample e\idence is adduced in this work to show that plaster has been used
b_\- the greatest of architects and artists in all countries for surface decoration as well as for plain
surfaces. Splendid stor}--tclling art has been produced in the past hy means of modelled plaster
decoration. Mr E. S. Prior, M..A., saj-s : " Plaster is the most impressionable of all materials which
give an architectural surface. Its response to the hands of the craftsman is sympathetic and
immediate. It has not to be chiselled like stone or wood, or have ideas hammered out of it like
iron : a touch of the finger gives it life." Plaster is easy to manipulate, reasonable in jirice, and very
durable ; can be polished, made washable, tir painted and gilt.

With regard to designing for ceiling and wall decoration in modelled plaster, the first and most
important factor is proportion or scale, and the second is the suitability to the structural and
architectural surroundings, and to the position, height, and forms which it is intended to enrich
and beautif)-. Neither delicacj- of modelling, fertility of imagination and resource, nor the power to
bring the beautiful forms into harmonious relation to each other, will Cfjndune the least fault in the
matter of proportion. The general architectural features give the scale, and the light in which the
work is shown should regulate the projection or relief of the decoration.

Small details and repeated parts should be avoided ; the great charm of this work is not only
that it should be artistically done, but that no part should be an absolute " repeat." The plan of
the decorations should be in harmony with the cornice enrichments, and in direct relation to the
architectural details on the walls. In large surfaces a repeated pattern is often unavoidable, but it
is obvious that they should be connected with each other in such a manner as to avoid all com-
plicated or intricate combinations. Repeated patterns that cover a large surface are not so
objectionable as small repeated parts. One cannot see the whole of a ceiling at once, yet it is
possible to see a suflicientlj- large section to comprehend the general .scheme and motive of the
design. There is no royal road to the art of design. It is easy to throw out a suggestion or to
recognise the wide permission of treatment granted bj- past examples of surface decoration, but to
embody ideal results in the art is somew hat difficult. The power of design may be said to be an
inborn gift, though fostered by the facultj- of observation ; and the art maj- be further cultivated
by study, especially of the materials to be used, and the place and surroundings for which it is
speciall)- intended.

Designing foF Ceiling and IVall Decoration. 241

With reference to the modelUng, the advantage of executing the work in the place instead of
for the place where it is to be seen will be obvious to practical minds. Here the true effects of light
and shade, and the best projection to suit the light and height, can be judged, arranged, developed,
and decided. The treatment of modelled ornamentation in a frieze or a cove is somewhat different
to that of a large surface such as a ceiling. The frieze must be first spaced to suit the intersections
of the ceiling mouldings with the cornice. If there are columns or pilasters on the walls, the main
features or mouldings on the ceiling must be planned to be in a line with the axes of the columns ;
this of course regulates the divisions of the frieze. If the light is cut off by reason of great space
between the top of the windows and the ceiling, it is necessary to make the frieze ornament in high
relief, but somewhat flat on the surface, so as to obtain definition of outline. If the work is exposed
to a full light, the projection should be reduced and the relief subdued, otherwise the work will have
a harsh or coarse effect. In a frieze subject to a strong side light, the vertical lines should be care-
fully dealt with, as the resulting shadows are much stronger than from angular lines. The treat-
ment of the modelling of ceiling ornament should be different from that employed for modelled
forms in any other situation. As previously mentioned, the matter of proportion or scale is the
essence of the work, and though it presents greater difficulties, it offers infinitely greater oppor-
tunities for artistic decoration.

In dealing with the subject of designing ornamental plaster ceilings, I think it will prove both
instructive and interesting, to give the opinions of an architect on this subject. These opinions are
extracts from a paper read before the R.I.B.A. on " The History and Uses of Plaster-Work, especially
as relating to Ornamental Ceilings," by Mr Basil Champneys, B.A. Cantab., and are as follows : — " It
is not very probable that in the usual practice of an architect the more elaborate forms will be
required. The figure paintings on ceilings which, under the auspices mainly of Italian painters,
were much in vogue during the last centurv", and of which many examples remain, are scarcely
likely to be revived, nor do many of us, I imagine, wish that the fashion should come back. For
practical purposes we shall find ourselves left to do the best we can with the use of patterns, from
which figure-work will be in the main excluded. And in the use of pattern-work, whether it be flat
or in relief, we shall find that ver}- much the same laws apply. The principal rule in either case
will be, as stated above, to observe great moderation and repose. So that if the effect be produced
by colour only, the colouring should be harmonious, and with but little difference in tone between
the pattern and the groundwork. If relief be used, the relief should be low. But there are other
considerations which must not be lost sight of Of these the most important is that the pattern
employed must not be one which leads in any one direction. On perpendicular surfaces a pattern
which has an upward tendency or growth is clearly in its right place. That which has a horizontal
tendency ma>^ often be legitimately and successfully employed. On a ceiling the principle is
altogether different. In this case the growth or tendency must either be neutral— that is to say, it
must lead nowhere in particular— or it must be either from the cornice towards the centre of the
ceiling, or from the centre to the cornice. It is obvious that all such patterns as are small, and
consequently have to repeat themselves, must come under the first rule and must have a neutral
tendency— that is to say, each section of the pattern used must be self-centred ; and there are
various kinds of patterns which will fulfil this requirement. Geometrical patterns, such as squares
or diamonds with central ornaments, reticulated or interlacing patterns of various kinds, and spirals,
are all, so far, admissible ; and it is clear that such a pattern may be of any size, so that it be less
than one-fourth of the ceiling to which it is applied.

" There are, however, some further reservations which may be made as to the use of patterns

242 Plastering — Plain and Decorative.

In the first place, rectangular patterns are ajjt to militate against another principle which I have
advocated — that, namel)-, of repose ; rectangular lines have a tendency to force themselves rather
importunately on the attention, and seem therefore less fitted for use in ceilings than those which
are more flowing. I should therefore advocate the use of reticulations or spirals where a repeated
jjattern was employed. There is at the present time a sufficient number of stamped or relieved
material which fairl\- well fulfil the conditions I have laid down. These, however, will be applicable
only to the more humble standard of decoration, and if a richer and more varied effect is sought,
resort may be had either to hand decoration in colours, or to plaster relief, and we shall then be
free to employ a design as large as the ceiling admits of, provided tJiat it fulfil the condition of
leading neither down nor across the room. It must, therefore, either focus towards the centre, or
radiate from the centre towards the walls. On first principles either of these methods would appear
to be equal!)- admissible. I have, however, found in jjractice that such designs as seem to grow
from the cornice rather than from the centre produce a more satisfactory effect. The reason of this
is not perhaps obvious, but I think that it may be accounted for. Upward growth is the best
'motive" of decoration in walls ; lines which appear to harmonise with this upward tendenc}% and
carrj- it forward into the ceiling, are ])erhaps naturally the more appropriate. As a confirmation of
this ]jrinciple, I have found that an entasis or a doming of the ceiling immediately above the
cornice, however slight, often tends to improve the effect. If this system is adopted, it usually adds
to the effect of the ceiling if a certain amount of plain surface is left about the centre. If the other
plan were adopted, that of radiating from the centre of the ceiling, I should be disposed to leave a
plain or neutral space above the cornice; so that the respective tendencies of the ceiling decoration
and of the wall decoration should not come into immediate collision.

"So much for the general principles which should govern the design of ceilings. As to the
particular tyjje of design which seems to give the best effects, I have already hinted my own
preferences in giving a brief account of the ceilings of past times. Xo school of design seems to
me so applicable as that of which the Slyfield ceiling is an example ; there strapwork is used in
connection with a subordinate pattern of swags and sprays, and combined with and enlivened by
the introduction of grotesques.

" In adapting the ' motives ' of this type of design it will be found that the base of the ornament,
the strapwork, can best be used to give breadth and freedom to the whole, while the subordinate
patterns or sprays may be .so handled as to prevent the breadth from degenerating into coarseness.
I have found by experience that there is no need to be afraid of the size of the main [jattern. The
largest curves that the space admits of may be .safely laid out, and dignity gained thereby, while
refinement may be insured by the interplay of the subordinate decoration."

With reference to the Slyfield ceiling, mentioned above, Mr Champney saj-s : " In a most
interesting, and, as I think, beautiful ceiling at Slyfield Manor House, in Surrey, the combination of
strapwork, aiiioriiti, and delicate ribbon -work and swags is peculiarly interesting, and it has, as I
may confess, been to me the ' motive ' of many an ornamental plaster ceiling. A comparison of the
ceiling of the chapel with that of a room below, which I take to have been the withdrawing-room in
the original and complete house, will serve to show — for I am convinced that the pair of ceilings
are of the same or nearly the same date — how great the scope of design was at this most prolific
period, the earlier half of the seventeenth century ; and I am disposed to think that this epoch, in
the matter of plaster design, bears the palm for perfection as well as for variety. It is at this stage
that the utmost boldness is found, I think, combined with refinement of design, while the most
jjerfect comprehension is shown of the effect proper to the material."

Surface Treatment of Modelled Plaster. 243

As an independent opinion on the subject of figure-work, modelling frieze and ceiling
ornamentation, and on surface treatment and texture, I cannot do better than quote Mr Stephen
Webb (probably the most artistic modeller of the present day), who in a paper on " Modelling for
Plaster Work," read before the R.I.B.A., gave his views with so much judgment and perspicuity that
they deserve perpetuation. With regard to figure-work in frieze decoration, Mr Webb says : " When
the human figure is introduced into work of this kind, it should be done with the utmost care, since,
while the lack of care or skill in the arrangement or distribution or even the drawing of the ordinarj'
decorative objects might be sometimes overlooked by anybody but an expert, the incorrect
modelling of a figure, simply as a figure, or its unskilful application to the design, is always obvious
and always disastrous. Use the figure, howe\er, in such a manner as to assist rather than interfere
with the design ; and if this needed any corroboration, I would point to the fact that few really
successful examples of its use are to be found in these days. There is seldom much to complain of
in the manipulation or drawing of the figures as figures. Even the worst failures of this kind
frequently give evidence of skill on the part of the craftsman in the delineation of the human
form. But the impression generally conveyed to the mind of a trained artist, when he looks on one
of these productions for the first time, is that the producer must have designed and modelled his
ornament first, and then bought a figure at a shop, or got one somewhere, and inserted it wherever
there happened providentiall}- to be room in the composition for a figure to sit or stand or sprawl.
If there be any motive at all apparent, it is that somebody has been extremely anxious to show
what an intricate knowledge he possesses of the manner in which the human figure is made. Now
that is a matter which, interesting and important as it may be to himself personalL}', has no interest
or importance in this connection to anybody else, since we can, anj- of us, find that part of the
business better done in the first fairly good group of statuary which we meet with. Assuming the
necessary knowledge of the drawing of the figure on the part of the artist in this work, what we
want of him is, that he show us how it may be used in some fresh and artistic combination with
other forms, so that a man of cultivated taste may receive pleasure in looking at the composition as
a whole ; and also, that we of the craft may not only receive pleasure, but haply some guidance to
our own efforts in the same direction."

In connection with the treatment of modelling for ceiling decoration, Mr Webb says :
" Raising and playing with the edges of forms, of which such effective use can be made in the
modelling of the frieze, is hardly ever admissible for ceilings. In fact, nearly all the ordinary
means in use by modellers, by which effect is got, are rather worse than useless here ; and though I
think I am able to see why you should model things on ceilings, since, properl\-, nothing else gives
such an effect of completeness to the decoration of a room, ... I feel that modelling on ceilings
should never be in the smallest degree assertive. . . . In no other relief work with which I am
familiar is the necessity for self-repression in the artist so constant, or any indulgence in striving for
cheap effect so severelj- punished, as in this. My own plan is to select what I consider the most
graceful and manageable forms in the stj-le in which the work is to be done, treating all the minor
and subservient shapes and connections very flatly, and the larger forms with extreme care, so that
there shall be no abrupt shadows cast from them — thinking, in fact, most about the management of
the light and the preservation of a breadth of effect, and getting no more shade an%-where than is
absolutel)- necessary to define the forms and give expression to the idea. It is, of course, well to
vary the central and leading objects as far as is practicable, since too much repetition is fatiguing
over large surfaces."

With regard to surface treatment and texture. Mr \\'ebb ver\- pertinently says : " If a piece of

244 Plastcyiiig— Plain and Decorative.

ornament has been clearly conceived, firmly laid in, and dexterously brought forward to the point
at which the last detail may be introduced, it should have a surface then which is far more interesting
to an artist than any other. But work done in that way assumes the possession, on the [jart of the
modeller, of a power and mastery of means which are not possessed by all makers of ceiling
decoration ; and as any hesitation — any feebleness or clumsiness — must appear in work thus left,
the usual, indeed the only, thing to do then, is to smooth it all over by a laborious and sometimes
costly after-process. I have heard architects and others lament the loss of effect in a piece of work
through this process of smoothing, but I do not think there is ever much real harm done, since the
ver\' fact of having resorted t<-> it may generally be taken as a pretty sure indication that there was
never anything in the surface worth preserving. It is, however, very grievous when, as sometimes
happens, in deference perhaps to the prejudices of somebody who should have known better, a
really artistic piece of work has to be handed over to the clay smoother or plaster carver and its
interest destroyed."

Method of Modellinc; in Situ.— The method for modelling in situ and also modelling
direct on slabs or plaques which are to be fixed on ceilings or walls is similar to modelling in
cla>-. It is advisable to make a rough sketch to scale on paper, not to make a finished sketch, to
leave the details of balance, light, and shade to be effected in the actual work and in position, where
these points can be best judged and an\' defects corrected. The principal lines and parts should be
set out on the plastered surface as working lines to regulate the main proportions, to act as guides for
right and left or reversed parts of the pattern, and to balance the whole. This is effected by setting
out lines so as to- divide the surface into squares, or diagonals, or both, according to the nature of
the design. The size and positions of these divisions are taken from the paper sketch. For
important and massive parts or works a small sketch model in plaster is advantageous. The lines
can be .struck with a chalk line, or made with a chalk or lead pencil and the aid of a straight-edge.
Circular lines can be formed with a compass, using the centres or intersection of the .square or
diagonal divisions as centres. The small lines and curves of the design are drawn by hand. Nicety
or finish is not here required, as the lines are used more for keying the surface than as a guide for
the modelling. The surface should be cut to form a key for thick or deep parts in the design, and
roughed to give a key for thinner or lighter parts. All plasters and cements have more or less
adhesive powers, but keying is necessary not only to ensure the requisite strength to support deep
or heavy parts of the enrichment, but also to resist the effects of vibration which is found in nearly
all buildings, especially on ceilings. Heavy or deep parts may be further strengthened by means of
nails or screws, which should be inserted into the wood work on ceilings, or joints in brick or stone
walls. A few flat-headed nails or clouts driven into the plaster will be sufficient for most purposes.
Extra heavy or deep parts can be supported by means of wrought-iron nails and tar ro[je, constructed
as described for " spike and rope brackets."

Having set out the divisional lines and serrated the surface, dust and damp the .serrations and
surface, then proceed with the modelling. For large surfaces only take in hand a space that can be
conveniently reached at a time without much moving, so that a right and left part of enrichment
can be worked in unison. Block out deep and heavy parts first, taking two or more, according to
the size on hand, so that they can be worked up by degrees or as the stuff sets. These deep parts
can be finished when modelling the adjoining thin parts. Small or thin ornament, such as foliage,
stems, flat leaves, are best finished in one ojjeration, or as the work proceeds. When it is incon-
venient to finish the part in hand in one operation, it should be finished before it is quite dry, as it
is difficult to lay the following coat on a dry surface. The stuff will not work freely or adhere to

Materials for Modelled Plaster Work. 245

a dry surface. Of course the surface ma}- be wetted or damped with water, but this is often
objectionable, as falUng water may spoil other work already finished ; too much water on the surface
also destroys the consistency of the finishing stuff, prevents cohesion, and weakens the finished
surface. When blocking out deep parts that cannot be finished in one day, or if the stuff .sets
before the next coat is applied, these unfinished parts should be roughed to give a key for the
following coat. The joints of a finished part should always be roughed to give a kej' for the
following parts. These items tend to prove that for general purposes no more work should be
commenced or taken in hand than can be finished in one day, and that the parts should be finished
as the work proceeds.

Materials for Modelled Plaster Work. — It is imijortant that the materials used for
the plastered surface or background on which the ornament is to be modelled, should be of the best
quality, and adapted for their position. A material suitable for interiors may not be equally suitable
for e.xteriors. For the foundation double lath or lath and half should be used. Oak laths are
strong and very durable for this purpose, but metal lathing, which is practically fireproof, is doubt-
less the best material for this purpose. It is false economy to build or execute artistic and valuable
work on a weak and unreliable foundation. For interior work, the groundwork may be formed
with well-seasoned and prepared lime and hair gauged with plaster, or with Parian or other white
cement. If the work is exposed to atmospheric influences, such as open corridors and vestibules,
the lime mortar should be gauged with Portland cement or other hjxlraulic cement. For exterior
work the groundwork may be composed of Portland cement or hydraulic lime. The proportions
and method of using these materials are described in Chapter V. If a matted or rough surface or
background is desired, the plastered surface should not be set or fined, but the floating coat should
be left with a rough surface to give a key for the proposed matted surface. The matted back-
ground should be formed with the modelling. Modelled work may also be executed direct on brick,
stone, or concrete walls, without a plastered surface. The wall surface must be hacked with a chisel
or an axe to give a key for the modelled work. The intermediate spaces between the ornamenta-
tion may be left in their natural state or brushed over with liquid cement or plaster, or a matted
background may be formed as the modelling proceeds.

With regard to the materials to be used for direct modelling or modelled work, the>- ma\- be
composed of most plastic material in use for plaster work as shown in the description of old stuccos,
Chapter IV. Plaster gauged with size water to retard the setting is a good and easih- worked
material. The setting can be regulated for from five minutes to as many hours. The subsequent
hardness can be improved by the addition of a small quantity of lime putty. Parian cement is an
excellent material for modelled ornamentation. Its slow-setting powers and ultimate hardness
cause it to be of essential service for modelled decorations. The addition of a small quantity of
silver sand or well-washed and finely-sifted sand gives the cement more grip and freedom in
working. The initial " set " of Parian cement often takes place nearly as soon as gauged, but it has
the property of resetting after being softened b\- adding water and reworking as already mentioned.
The setting may be retarded by air-slaking the cement from twelve to twenty-four hours. Care
must be taken when exposing the cement that it is put in a dry place. Damp will make it lumps-.
and otherwise spoil it for this purpose. For interior work, a little marble dust added to any of the
above-mentioned materials will render them bright, hard, and washable. The plaster work made of
" rye dough " mentioned by Le Neve may also be emploj-ed for modelled decorations. The r\-e
meal was probably used to retard the too rapid setting of large surfaces, thus enabling the modelling
to be longer continued. Mr G. T. Robinson, who has tried it, says " it makes an excellent com-

^■i^ Plastering — Plain and Decorative.

pound for modelling in," and that " it retains its pliancy long, dries hard, and is of a beautiful old-
ivory tone." Portland cement, selenitic, or hydraulic lime, owing to their resistance to atmospheric
influences, are the best materials for exterior decorations. The setting of Portland cement can be
accelerated by adding a small quantity of fresh Sheppey or Medina cement. Either of these
cements may be used without fear of deteriorating the necessary hardness of the Portland cement
for this purpose. Portland cement is rendered more pliable by the addition of a small ijuantity
of old lime [lutty, and the addition of a little sand renders the manipulation freer. For deep
parts of modelled decorations the addition of a small quantity of hair or fibre gives tenacity
to the material used for blocking out. This also gives greater freedom in working, holds the
material in position until set, and prevents it dropping while the work is in progre.ss. These
materials can be coloured as desired by using the ingredients mentioned for stuccos, scagliola, and
concrete.

Modelling IX Cement. — Figures of the human and animal forms are frequently made in
Portland cement or fine concrete for exterior decoration, and in white cement or ]jlaster for interior
decoration. The usual way is to model them in clay and then mould and cast them, but it is more
economical, besides offering greater \aricty in conception and manipulation, to model the work-
direct in the final material.

For figures of the human form, the modeller, like every other creative artist, begins by making
a sketch model of the proposetl figure, which serves to fix and regulate his conception while working
at the real figure, and enables him to alter it at pleasure, while otherwise this would be difficult.
The model, though on a small scale, must bear a resemblance in form, position, features, and
drapery to the future full-sized figure, and it must be so well done that it will serve as a guide
throughout. For a figure life-size, or for a figure with outstretched arms, it is necessary to [jrovide
an iron frame sufficiently strong to bear the weight of the cement until set, and also act as an internal
support for thin or projecting parts in the figure. From careful calculations of the sketch, the iron
frame is prepared in such a way that iron rods and, where possible, strong lead pipes or gas-pipes,
who.se flexibility facilitates later alterations, give the body as well as the extremities a secure inner
support. For large figures, an outer but lighter frame, composed of hoop iron bands or with wire
netting, is fi.xed on the main iron frame so as to form a core in the thickest parts of the figure.
This iron skeleton is then clothed with cement and modelled.

The same process used for modelling a figure in clay should be used when modelling direct in
cement, therefore the naked figure is modelled first, for although it is to be clothed, the greatest
possible care should be bestowed upon the body. However voluminous the folds in a figure may be,
there are always certain places where the body is visible, therefore every limb must be natural and
anatomically correct. The less drapery the finer must be the work bestowed upon the naked figure,
that it may form a harmonious and beautiful whole.

The method of constructing the iron work, coreing out materials, and using same for figure
work in cement or fine concrete, is further elucidated in Chapter XIX.

\V.\X Modelling. — The modelling of medallions for portraiture is considered more difficult
than modelling on the " round," i.e., an object free of background, as a statue or an apple. The
main object is to produce the effect of roundness with the lowest possible relief, contour being
obtained by fine gradations and delicate touches. Medallions may be modelled in wax at home,
as it does not require much space, and is not dirty work. Thus the studious apprentice can pass a
part of his leisure time in a pleasant and profitable way. Modelling in wax has the advantage over
clay that the work can be commenced, set aside for an indefinite time, and then resumed without

Modelling in Tow. 247

injury. The wax is made pliant b)- slightly warming and working by hand. Employ it in the
same way as clay. Steel, brass, bone, and wood tools are used for modelling wax. They work
freely if rubbed with oily rags. Medallions are best modelled on a sheet of plate glass, as it can be
reversed, and faults in outline can thus be easily detected.

Modelling Wax. — There are various ways of preparing this material. The following are the
best known. Dissolve in a pipkin over a slow fire a quantity of pure yellow beeswax, then add a
twelfth part of powdered resin, and a tenth part of Venice turpentine, and stir well, taking care that
it does not boil. Add flake white until of the desired consistency. Test the plasticity of the wax
by taking out a small portion on the end of the stirring stick, and after it is cool, work it in the
hands until plastic. If it is too sticky, add more pure wax, as there is excess of turpentine. When
worked and kneaded, it should draw out into long strings before breaking. Another kind is made
in the same way, using the following materials : — 50 parts virgin wax, 4 parts Venice turpentine,
and 2 parts pure lard, adding fine sifted whiting ad lib. Another kind, generally used by sculptors,
is made by dissolving i \ lbs. of beeswax, i lb. of lard, and \ gill of linseed oil, then add i lb. of flour.
If too sticky, add more flour, and knead all together. Another kind, commonly used in London, is
composed of 10 parts of beeswax, 12 parts of lard, and 3 parts of olive oil, all by weight. Dissolve
these ingredients together, and when cold, add fine sifted whiting until of the desired consistency,
and knead together. Paraffin wax is sometimes used as a basis, and some kinds of squeezing
wax are also used for modelling purposes. Other wax recipes are given in the Appendix.

Beeswax. — This is a thick, viscid, tenacious substance, excreted by bees, and used by them
in the construction of the combs. There are several artificial waxes made from fats, resins, &c.
Chinese wax is derived from an insect, the Coccus cerifenis. Japan wa.x is of a vegetable nature.
Carnauba wax is also derived from a plant found in Brazil. Myrica, or wax myrtle, is obtained
from a North American shrub. Mineral wax is a bituminous substance found in the Carpathian
Mountains near Starick. Beeswax, when pure, is the best for all moulding or modelling purposes.
It is sometimes adulterated with artificial wax. English or American beeswax is the best for
all plastic purposes.

Modelling in Tow. — Modelling large work for temporary decorations is done in tow and
plaster, gauged with size water. This saves moulding and casting, and the work is strong, light, and
dries quickly, and if painted, will stand exposure to the weather for a long time. There are \-arious
ways of modelling in tow. One plan is to steep common hay-bands in plaster, gauged with size
water, lay them on rough framework, gradually building up until the outline is obtained. The work
is then finished with chopped tow and gauged plaster. Another way is to dip sheets of canvas or
tow in gauged plaster, and lay them upon a foundation of loose tow, hay, or straw, which being soft
and compressible, the rough form can be easily obtained, while the canvas and plaster remains
plastic. When it is set, the modelling is finished with fine chopped tow and gauged plaster. If it
is wanted extra smooth, the model is finished (when in a green or moist state) with fine plaster,
gauged \\ith size water. Bold effects in draperies are obtained by dipping long strips of canvas into
gauged plaster, and arranging it into folds, while the plaster is soft or unset. This class of work is
often employed in Italy, Austria, and German)', and has been used in this country for the decora-
tions of triumphal arches, &c. I have used it for large capitals and figures in theatrical properties
with good results. A heroic statue of Schiller, b\- Professor Shilling, of Dresden, was constructed in
this manner during the celebration of his centenar)- in the Alt Markt, and afterwards removed to a
garden, where it stood for years.

Architectural Model Making.— Architectural model making is the formation of small

-4^ Plastering — Plant and Decorative.

models made to scale of buildings, land, &c. They are used to supplement the drawings of build-
ings, &c. Models afford a clear and correct guide and reference in law cases, and enable non-
practical men, or those who cannot interpret plans, sections, and elevations on paper, to see and
understand the various parts and positions of buildings, &c. Architectural models are useful to
enable architects and designers to judge the effect of their works on the round. Models afford a
ready solution as to the requirements of clients. When definitely designed, a model may avoid
extras and subsequent recriminations. Models made in plaster of some of the principal ancient and
modern buildings from various parts of the world are to be seen in many museums.

V'arious materials are used in the construction of architectural models. Cardboard or thin
slabs of fibrous plaster are generally used for large plain surfaces. Corrugated paper is useful for
many parts of cardboard models. Paper models are fixed with wax, glue, wire, &c. Water-colour
is used for getting any desired tint. Liquid wax is sometimes spread over cardboard surfaces on
which sizes and forms of stones, &c., can be shown by indentations and modelling. French putty
is sometimes u.sed for sketch models. It can be coloured with powders, and when s|jread over
cardboard, readily takes any form of surface. It is, however, too soft for permanent work, and is
onl)- used for trial work, or for temporary purposes. Modelling wax, also paraffin wax and Venice
turpentine, dissolved together, are excellent materials for surfaces. Powdered colour will give any
tint, and any desired te.xture is obtained b\- the mi.xture of suitable materials, such as silver sand,
bird sand, marble dust, granite dust, sawdust, cork dust, &c. Ground rice gives a fine granulated
surface, and French chalk a soft silky one. Wax gives the best results, as it takes and retains both
colour and te.xture with permanence. Fibrous plaster slabs for the construction of architectural
models may be cast to the desired sizes, or large slabs cut up to fit the various parts of the model.
Mouldings may be " run down," and then fixed as required. A better way is to cast them with the
slabs in one piece. Ornamental parts may be cast in a similar way, or they can be worked on the
model in modelling wax, gesso, or plaster. Small models may be entirely constructed of modelling
wax. A plaster core is fixed on a modelling board to reduce the quantity of wax, and steady it
while being modelled. Architectural models may also be entirely composed of fibrous plaster.
The model is first made in plaster or modelled in clay, and then jelly moulded, and a fibrous
plaster cast obtained. This is a good and economical method where a strong or permanent model
is desirable. The cast being in one piece, without joints, it combines lightness with strength. It
can also be made in sections to show the interior. The model can be coloured as required. If
necessary, it may be further hardened to resist damp and wear by the same process as described for
fibrous plaster.

CHAPTER IX.

MOULDING AND CASTING.

Plasterer's Shop— Patent Plaster Box— Frontispiece— Squeezing Wax— Casting Wax— Moulding
Wax— Wax Moulding— Skin Wax Moulding— Waste Wax Moulding— Making Front and Open
Front Wax Moulds— Making Jointed, Surface, and Front and Back Wax Moulds— Making
Moulding Pieces from Front and Back Moulds— Wax Piece Moulding— Moulding Plaques-
Chasing Wax Moulds— Clay Squeezing— Clay Piece Moulds— Plaster Waste Moulding-
Moulding FROM Life— Plaster Piece Moulding — Modillions — Model Making of Balusters —
Plaster Piece Moulding Balusters— Duplicating Piece Moulds— Casting Balusters— Plaster
Piece Moulding Vases — Casting Vases— Oiling Plaster Moulds — Solutions for Moulding and
Casting— Oiling Wax Moulds — Ball Oil Pot — Gauging Plaster — Uses for Old Plaster — Plaster
Casting — Hollow Casts — Furred Moulds — Strong Plaster for Casting — Casting White
Cements — Casting Portland Cement — Water Seasoned Plaster Moulds — Casting Cement
Mouldings (Waste Mould Process)— Pressed Cement Work — Method of Reducing or En-
larging Irregular Figures.

Plasterer's Shop. — A plasterer's shop should be drj- and well lighted, and contain a fireplace or
stove for heating water and dissolving wax or jelly. Good and sufficient benches are indispensable.
The tops may be composed of wood or Portland cement. A wood grating about 20 inches wide,
placed in front of the casting benches, raises the bo>-s and keeps the men's feet dry and clean. There
should be a large shallow tub for hot water, or better still, a large concrete tank. A square bench,
placed so that a man can get all round it, will be found useful for moulding and casting large centre
flowers or panels. There must be shelves for stacking moulds and cast work. Clean water tank,
and size water tub, and a slush tub are necessary. The slush tub should be placed under the gauging
spot, so that it will be convenient for washing gauge pots in, and any excess water will run into it. A
sufficient number of earthenware, guttapercha, or copper gauge pots, and a water measure, will soon
repay the cost. Other requisites are a few slate slabs for making plaster grounds on, and also for model-
ling and moulding; a quantity of running rules, thickness rules, and feather-edges; a mitre box, square,
compasses, jack-plane, chisel, saw, vice, shears, and files. Strips of lead or zinc, about 6 inches wide,
are useful for fences when moulding large circular work or making cases. They can be used with more
speed than clay, and will serve repeatedly. Pails, oil, shellac, soap, wax, and jelly pots are requisites.
Fish skin is an excellent article for rubbing down plaster or cement surfaces ; it is not affected by
water. Dutch rush {eqiiisetum) is useful for cleaning off seams and polishing plaster. Cement and
plaster boxes are important. A good yard attached to the shop is necessar>-. The j-ard should
contain tanks for water and cement work ; bins for putty, setting stuff, coarse stuff, sand, crushed
granite, and other aggregates ; storage for scaffolding and general plant ; an enclosed shed for
cement, sacks, scales, canvas, plaster, and fibrous laths are all useful. Where specialties are made,
more plant is required in the plasterer's yard and shop. A considerable amount of room is required
for concrete work and artificial stone. The following is a good plaster box.

P.\TE\T Pl.\STER Box.— Illustration No. 88 shows a novel form of a self-feeding plaster box

JIO

Plastcriug — Plain and Decorative.

which I have introduced. It kccjjs the plaster dry and clean, and it is easily got at when gauging.
It is made to hold 4 bushels of fine jjlaster and 4 bushels of coarse. The inside size is 3 feet bj- 3 feet
by I foot 3 inches. Open trough in front (sloping) about 8 inches deep and 6 inches projection.
The front of the box does not extend to the bottom, so as to allow the plaster to run into the trough.
A division in the box and trough keeps the fine plaster separate from the coarse. The top slides in two
pieces, and keeps the plaster clean. A shelf is formed underneath, on which the working utensils
are placed when not in use. G is a " gauge spot," on which the gauge pot stands while required.
This is fi.xed with a fall outwards, to allow any spilt water to run into the slush tub s. Another
gauge spot can be fixed at the other end of the plaster box. An independent gauge spot placed in
front of the box, so that two or more men can gauge at the same time, is often useful. In this case
the slush tub is placed in front of the gauge spot, and a water tub and size water tub should be

placed at the ends, w is a wire clay cutter. This is
formed with a copper or brass wire about 20 inches
long, and fastened to two wooden handles. It is used
for cutting tempered clay blocks into sections, also for
cutting and jointing plaster grounds, c is a clay-beater.
This is composed of hardwood, and is 18 inches long.
It is used for beating out sheets of clay which have first
been tempered by beating with an iron bar or pii)e. j is
a jelly pot ; M is a water pot for measuring the water for
gauging ; F is a fibrous plaster brush ; r is a gauge pot ;
and H is a moulding box.

Frontispiece. — A combined modelling and mould-
ing shop is shown on the frontispiece. This elaborate
and allegorical design is the official emblem of the
National Association of Operative Plasterers. On the
plinth at the base is the plasterers' coat-of-arms. On the
shield is a stock-brush, a laj'ing and a gauging trowel.
On the bar is the word " Friendship." On the top is a
helmet and mailed arm, with a hand holding a plasterer's
hammer. The shield is supported b)' two griffins, and
on the ribbon scroll is the motto, " Let brotherly love
continue." The escutcheon is surrounded by laurel
leaves. The dies of the pedestals are enriched with sunk
ovals and raised foliated wreaths of flowers. In one
of the ovals are the gauging trowel, hand-float, and plumb-bob, and in another are the square
and compass. The figure on the pedestal at the left hand side represents Architecture, with
a globe at the side. The figure on the right hand is Art, with a bust at the side. The lower
half of the frame is the modeller's studio. The youth on the left is casting ; the two men sitting at
the bench in the middle are cleaning up, trimming and jointing ornaments. Each man has a moulding
box in front of him to fit and .square the work on. The ap|>rentice at the bench in front is waste
moulding. At the easel a modeller is at work on a medallion. On the left side is a statue of the
Venus de Milo, and on the right is a draped figure. At the back on a pedestal is a large bust, and
on another pedestal is a figure of Cupid. On the walls and benches are casts of an arm, angle
pieces, bed moulds, columns, caps, centre flowers, diapers, friezes, frets, guilloches, lions' heads.

No. 88. — Patent Plaster Bo.x.

Squeezing and Casting IVax.

251

medallions, panels, soffits, vase, and portions of enriched cornices. The top half of frame is a room
with the plasterers busy at work on the walls, after having finished the richly coffered ceiling and
enriched cornice. The plasterer at the left is laying on gauged cement for mitring the window
architraves, the one in the middle is fi.xing ornaments in the door architrave, and the one on the
right is setting the panels. A bust of Minerva forms the cap or top finish to the keystone of the
arch. Above this is the motto, " United we stand, divided we fall." In the tympanum of the
pediment are two stalks of myrtle, tied with a love-knot, and encircled with a wreath of olive leaves,
typical of friendship and peace. The upper entablature is adorned with swags and festoons of flowers
and ribbons, and in the centre is the title of the Association. At each side are two Cupids supporting
shields, with mottoes. On the top are two vases with flowers, and two Cupids holding cornucopias
or horns of plenty. The apex or centre figure represents Unity, crowned with a laurel wreath, and
in her hands a bound bundle of reeds. The bound bundle of reeds signifies that a single reed may
be bent or broken ; but a united bundle, bound with the bands of harmony and justice, cannot be
bent or broken. Another meaning is that a united bundle of reeds will stand on end, whereas if
divided the single reeds would fall ; this being also the origin of the motto, " United we stand,
divided we fall." The mottoes and sentiments on the emblem are good alike for employers and
employees. Their interests should be identical, and in the event of any unhappy diflierences or
disputes, they should refer to the happy medium of just arbitration and conciliation, and not resort
to the unwise and unsatisfactory issue of lock-outs and strikes.

Squeezing Wax. — Squeezing wax is used for taking an impression of metal, wood, stone, or
plaster models for reference purposes. The surface of the model should be dusted with French
chalk to prevent adhesion and discoloration of the model. Where there are several pieces required
for one model, the joints should be dusted, and the whole cased with plaster to keep them in
position. The squeeze is then filled in with plaster, thus producing a replica of the model. There
is a variet}- of wa\s for making this material. The following are respecti\ely English, French,
Belgian, and Austrian recipes: — i. Take i lb. of pure beeswax, A lb. of lard, and i gill of linseed
oil; melt o\er a slow fire, then sprinkle in i lb. of flour, and stir well, then pour the whole out on a
slate or bench and knead all together. If the wax is too sticky, add a little flour, and knead until
of the desired consistenc)-. 2. Take i lb. of beeswax, li lbs. of lard, and i gill of olive oil; dissolve
over a slow fire, and add sifted whiting until of the desired consistency, and knead as before.
3. Take \ lb. of beeswa.x, \ lb. of Burgundy pitch, and dissolve o\er a slow fire, and add \ pint of
olive oil ; gradually stir in equal parts of flour and fine sifted whiting until of the desired
consistency, then turn it out on a slab, and knead it until it is of a pliant nature, adding
whiting as required. The more it is worked, the better it will be. 4. Take 2 parts of beeswax,
I part suet, and i part turpentine ; dissolve, and add fine whiting as before. If coloured wax is
desired, add yellow ochre, Paris white, green, or vermilion, according to taste. Paraffin wax mixed
with olive oil and whiting, prepared as above, is also used for squeezing wax.

Casting Wax.— Wax combined with other materials is used for casting silver or bronze
models, also for piece moulding. The Italian artists use a casting wax made simply of beeswax,
Venice turpentine, and finely sifted wood ashes. After the wax and turpentine is melted (as in
making modelling wax), a large proportion of ashes is stirred in until the mass is stiff". It is then
kneaded over a charcoal brazier until it is quite plastic. This wax is used in making part of a
piece mould on marble when it is difficult to get at, or where the swelling of plaster would be
disastrous in a fragile figure. The surface of the wax is dusted with French chalk before taking the
impress. Wax joints are also dusted when piece moulding. Girardon, the celebrated sculptor, when

252 Plastering — Plain ami Decorative.

casting the statue of Louis XIV., used a wax composed of lO parts of pure yellow beeswax, i jjart
turpentine, i part lard, and i i)art Hurgund)- pitch, all by weight. Bouchardon used for the
equestrian statue of Louis X\'. a wax consisting of 2 lbs. of pure j-ellow wax, i oz. of tallow, and
\ oz. of resin.

Moulding VV.VX. — Moulding wax is used for making moulds for plaster casting. It consists
of I ])art pure beeswax, and from i to 2 parts of powdered resin, dissolved in a metal jrat, over a
slow fire, or on a hot plate. The wax should not boil, as boiling destroys the virtue of the wax,
and renders the mass hard and brittle. The quantity of resin varies according to quality of the wax.
A rich wax will carry more resin than a poor one. Poor wax is improved by adding from i to 3 oz.
of mutton suet, or best white tallow, to each pound of wax. Old wax that has been frequently
used becomes short, and often also full of small pieces of plaster, clay, wood, &c. It can be cleaned
by thinning, with extra heat, and then pouring it through a hot sieve into another pot. Old and
short wax is corrected by adding a portion of new wax and tallow, also hy mixing a new batch of
wax and resin with the old. When a hot plate is used, the pots should be broad and shallow, .so
that the heat can get to a larger surface. .\n a\erage size is 14 inches diameter and 6 inches deej).
They are generall)- made of block tin or copper, and should have a wide lip, so that the wa.x ma}' run
freely. There should be handles at each side. For ordinary small work, a common saucepan with
a lip is suitable. Where steam is generated, the waste steam can be utilised for melting wa.x
and jell_\-. In this case the pots are made deep, and placed in an iron jacket or fi.xed iron tank.
Wa.x may also be dissolved by means of hot water in the same way as used for jell}'. Wax or jelly
melted by steam or hot water is more uniform in heat, and lasts longer. To know when wax is
cool enough to pour on a jjlaster original, oil or wet the finger, and dijj it into the wa.x. If it can
be borne comfortabh', the wa.x is in good condition for moulding. Never allow the wax to get too
cool, or a skin will form on the surface, or it will become crinkh- and unfit for moulding.

Wax Moulding. — When about to take a mould in wax, the original must be dusted and
placed in clean water to stop absorption. It should not be kept in the water too long, as excessive
soaking spoils a good original. It ought to be taken out three or four minutes after the air bubbles
have ceased to rise. After soaking, jjlace the original on edge to allow the surplus water to run
off, then remo\e the surface moisture with a sponge. This is better than a brush, as it is quicker,
cleaner, and not so liable to injure the face of the original, and make it rough.

.After sponging the surface, place the original on a moulding board in such a position that it
will take the least possible quantity of wax to cover the highest points. Then beat out a sheet of
cla}- about \ inch thick, and smooth the face with water and a gauging trowel. Afterwards cut
it into strips of the required widths to form "fences" (sometimes called bandages), and fix them
on edge round the original, where required, to keep the liquid wax from running out. If there are
any butt or angle joints in the clay fences, they can be fixed by pushing small nails into the cla}'.
The use of sweet oil for smoothing clay, or preventing it sticking to wax, is a serious mistake,
because it spoils the clay. Water is all that is required. For the same reason, clay water, in place
of oil, should be used for the joints of wax piece moulds. It is also cheaper, cleaner, and works
more freel}'. When moulding originals, such as soffits, friezes, or other enrichments ha\ing straight
sides or ends, no clay should be used as straight fences. Clay is well adapted for forming circular
fences, also for short end fences. Plaster fences are (juicker, and give a truer line to the outside of
the mould. They are easily kept in position by pressing small pieces of clay on the moulding board
clo.se up to the plaster fence. When moulding bed moulds, such as eggs, &c., place the original in
a moulding box, fix a plaster fence at the front, and clay fences for the ends. The moulding box

Skin and Waste IVax Moulding. 253

enables the original to be canted over, so that less wax is required. When the original is placed,
and the fences secure, brush the face of the original lightly with clean water to remove any dirt
and prove that suction is stopped, or until the face of the original becomes glossy or shines, then
pour on the wax. This should be done on the lowest part of the ground of the original, thus caus-
ing the wax to run upwards, and forcing the air up, and helping to obviate blubs in the mould.
When the wax begins to run over the face of the original, follow up with more warm wax, as
the wax soon cools in running over a damp surface, and is liable to become crinkly.

Skin Wax Moulds.— Wax moulds having deep parts, and containing a thick body of wax,
are difficult to ease when casting. In order to avoid this, and obtain a nearly uniform thickness, the
moulds are " bled " — that is, the wax at the thick parts is allowed to run out, leaving a wax skin
varying in thickness from l inch to \ inch on the surface, and about i inch at the sides. This
enables the mould to be warmed and eased more freely, and with less liability to breakage.

A wax mould is " bled " by cutting with an oiled knife the skin of the wax at the deep parts.
When the wa.x has been poured on, a skin is formed owing to the cooling, but the deep parts take
longer to firm. This gives a guide for cutting the skin. After this is cut, turn the mould over to
allow the liquid wax to run out, taking care that the hard parts of the skin are first oiled or brushed
over with clay water to prevent the liquid wax from adhering to the other parts of the mould.

Large moulds having deep sections, such as a centre flower, may have 3 or 4 inches thick of
wax at the outer rim. This kind of mould is cumbersome, and takes up a large portion of wax
that may be wanted for other purposes. To save this, the mould is " bled," but not in the same
way as just described, because the mould being large, it is difficult to turn over. This is overcome
by cutting openings at the outer rim, and forming clay channels for the liquid wax to run out into
the wa.x pots. If warm and soft, the excess wax may be moved with a piece of stiff clay; and if
cool and firm, it can be moved and smoothed by the fingers, which are previously greased to
prevent sticking. After the excess wax is run off and smoothed, the surface is brushed over with
thick clay water, and a plaster case made to keep the wax in position. If the case is too large to
be convenient!}- floated over with a wet gauge board, fix a straight-edge at each side of the mould.
Bone them to see that they are both level. These will serve as screeds or bearings for a floating
rule when forming the dots on the back of the case. This forms a level back surface, and allows
the mould to stand level and steady on the bench.

Waste Wax Moulding. — Waste moulds are used to save the expense of piece moulding
clay models, where one cast only is required for making a moulding piece, or for cleaning up the
cast before being permanentl>' moulded. Plaster is u.sed for waste moulding models on the round
and similar works. Wax is used for small, flat, and delicate work. If the model is undercut, the
wax will leave the cast sound if properly made. The clay model, if ordinarily soft, does not
require any jjreparation to prevent the wax from adhering. If the clay is firm or semi-dry, it
should be gently sprinkled with water, and the excess water blown off, or it ma\- be carefully
brushed with a soft camel-hair brush dipjjed in water. Care should be taken that the artistic
touches of the modeller are not spoiled, or the model otherwise disturbed. In no instance should
oil be used. When the clay or plaster fences have been fixed so as to prevent the wax escaping,
and to form a ground if an original is required, pour the wax on the ground part until the model
is all covered. When the wax is cool, but not stiff", turn the mould over and pour the surplus wax
off"; or if large, cut the fences at the side to allow the wax to run freely out until there is onl>- a
very thin skin of wax on the model. After this is firm, brush it all over with clay water, taking
care that any undercut parts are stopped with clay, so that the plaster case will draw. The case

254

Plasteriiis[ — Plai)i and Decorative.

is now made, the mould tiinied up, the clay carcfull)' taken out, and the mould well washed out
with soa|) water. It is dried and oiled, and washed with soap water to clear off the excess oil,
so as to obtain a white and sharp cast. The mould is then filled in, and when the plaster is set,
prize the case off, and place the mould into hot water until the wax is soft. The skin of wax can
then be drawn or ijcelcd off without injury to the cast.

To M.\KE .\ Front Wax Mould. — Having committed the foretjoing notes on wax moulding
to memory, the art of wax moulding will be readily achieved. A front mould in wax i.s used for
moulding soffits, patcras, small bed moulds, or an>' other enrichment that would draw in one piece.
The original model of some of these enrichments arc square on the sides, or ends, or both, therefore
it is necessary to splay the square parts to allow the mould to draw in one piece. The splayed
parts are, of course, reproduced in the casts, and must be trimmed square with a knife so that thej'
will joint and fit their beds. In some instances, such as small bed moulds or top leaves, the splayed
parts on their outer sides require to be trimmed a little beyond the square, so as to give more relief

No. S9. — Fig. i — Makix<; a Front Wax Moui p.

Fig. 4 — Making a\ Open Front Wax Moui.i'.

to the work. A small soffit " in the cla)' " is selected for an example of making a front mould, so
as to exemplify making a mould from a clay model and also a moulding piece of same. To mould
the model of the soffit, first make a plaster ground about J inch thick, and in length about 2 inches
longer and 2 inches wider than the model. This allows i inch on both sides and ends for a ground,
and consequently a rim i inch wide on the sides and ends of the mould. The side rims of a mould
should for this class of work not be less than l inch, so as to allow a fair bearing for the fingers to
ease the mould when casting. Having made the ground, la\- it on a moulding board, then lay the
model on the ground G, as shown at Fig. i on the subjoined illustration (No. 89). It will be under-
stood that the design of the soffit is modelled on a plaster ground, and that it is jointed. The
thickness of this ground may vary from i inch to | inch, according to the length and width of the

PFax Moulding.

<b-

model. As this is only intended for the purpose of making a "waste" mould, to obtain a "solid"
moulding piece, the model need not be fixed permanently by scratching and bedding with plaster,
but simply splaying the sides and ends with soft gauged plaster will be sufficient to hold it in
position until it is moulded. Having splayed the sides and ends just as much as will allow the
mould to draw, fix a plaster fence, F, against the ground, and then a clay fence, E, on the end.
Repeat this on the other side and end. Plaster fences being straight and stiff should always be
used for the sides of wax moulds, as they form the sides of the moulds straighter than if made with
clay fences. When casting, two or more moulds arc laid on a bench side by side, straight sides fit
close, and prevent the waste of plaster which would occur if the sides were irregular. Clay fences
for the ends are best, because they readily take the curves which are often found in the ends of
some models which are necessitated by the design. Clay fences are also useful for supporting the
side fences, as they can be turned round the ends of the plaster fences, as shown in the present
example. One or two clay dots fixed against the sides are also required to keep the side fences in
position. Having fixed the fences, carefully brush the plaster grounds and fences with water, and
pour on the wax as previouslj' described. If the model is deep or undercut the mould must be
"bled " to allow the mould to leave the moulding ]Diece more freely, as already mentioned. \ow
take off the mould, wash it out and lay it on a moulding board, and it is ready for taking a mould-
ing piece.

The method of making a solid moulding piece is elucidated by Fig. 2 on illustration No. 89.
This shows a section of the mould and the moulding piece (the latter is indicated by the dotted
surface). To make the moulding piece fix two wooden rules, R, R, at each side, so as to form straight
sides and give the desired thickness for the moulding piece. The mould is now taken oft", thus
leaving a solid moulding piece. It is then cleaned up, when it is ready for taking any reasonable
number of moulds from. This, of course, is done precisely the same way as described for moulding
the model. A section of the moulding piece is shown at Fig. 3.

To Make an Open Front Wax Mould. — An open front wax mould is one where a part of
the profile or back section of a model is left open in the mould, such as a bed mould, where one side or
front has a curved outline ; for instance, an egg-and-dart enrichment as shown by the back elevation
of a model of an egg enrichment at Fig. 6 on illustration No. 89. The model is fixed on a plaster
background and on a plaster topground, as shown at F, Fig. 4. This figure shows the model of the
egg enrichment and the plaster fences in a moulding box, on a moulding board, during the process
of making the wax mould. The model is sometimes fixed on a background only, keeping the back
of the model flush with one side of the ground, as shown by the section of the model and ground
at Fig. 5. When this method is adopted it is placed in a moulding box and against a plaster
topground, as shown at F, Fig. 4. This ground illustrates both methods. If the model was placed
ill the moulding bo.x and then moulded, the wax would adhere to the wood and spoil the mould,
hence the use of the plaster grounds. It will be understood that three or four of the models are
jointed and fixed together on the ground so as to make a suitable length for casting, as shown by
the enrichment at Fig. 4, which is composed of four eggs and darts, or in other words, the design is
repeated four times. The length of the cast must be regulated according to the thickness of the
model, or so that the cast will be sufficiently strong to carry its own weight until it is fixed. Having
fixed the model on the ground, place it in the moulding box K, Fig. 4. This box must be canted
by raising one side until the profile of the enrichment is about level. The box is held in position
by means of two clay dots at each end, as shown at D, n. Canting the model enables the mould to
be made of a more uniform thickness, which saves wax and enables the mould to be more readily

Plastcriitiy — Plain and Decorative.

eased when casting;. If the model was moulded in a level position, as shown bj- the section of the
model and <,'round at V'vg. 5, it will be self-evident that the mould would be square, and take about
one-fourth more wax than if moulded on the cant. Havinjj fixed the mouldinj^ box in position,
place a plaster fence on the moulding box and against the ground, as shown at s. This side
fence is secured by two claj- dots as shown at c, C. This done, fix a cla)- fence on the end, as shown
at K. Fix a cla\- fence on the other end, and the whole is now read)- for the wax. This is, of
course, clone as pre\iously described.

Having made the mould, a solid moulding piece is next made from it. Moulding pieces that
are " made up," that is, where two or more casts of the original model are fixed on a ground to
make up a suitable length for casting purposes, seldom stand moulding more than twice, as the
prolonged immersion in water when soaking to sto]) the suction of ch y moulding pieces tends to
weaken the fixing, and the various pieces generally leave the ground and come with the mould when
it is taken off. This difficulty is overcome b\- making a "solid moulding piece," or an "original," as
it is often called. A .solid moulding piece is generally made b)* fixing wooden rules against the
sides of the mould as guides for obtaining the thickness and forming straight sides of the moulding
piece similar to that described for making the moulding piece of .soffit, Fig. 2. But to make a scjlid
moulding jiiece of bed moulds, similar to Fig. 4, clay or plaster templates are fixed against the ends
of the moulds to act as thickness guides and for ruling off. The thickness and form of the mould-
ing ])iece ma\' also be regulated by the e\-e, using the end rims of the mould as lines to work fmm.
This is shown at Fig. 8. The dark surface being the mould, and the dotted surface the ground
of the moulding ]3icce, the dotted line on the dark surface indicates the profile of the enrich-
ment. When casting, two or more moulds are placed together on a bench or moulding board,
and after the plaster is poured in the back and top surfaces are formed b\- ruling the plaster over
with a straight-edge, using the end rims of the mould as bearings. It is here that the open part
of the mould and its necessity or u.se is seen. This side or top of the cast is formed, of course,
with a straight-edge, as already mentioned. The .section of two moulds as placed together on a
bench when casting is shown at Fig. 7. Sometimes four or six and even ten moulds are placed
together and filled in at one operation.

To M.VKK A Jointed Mould. — Sometimes it is desirable that enrichments should be cast
with finished joints, such as when casting with cement, where it is difficult to trim the joints of the
hard material with a knife. In this case a jointed mould is employed for producing the jointed
cast work. Jointed moulds are useful for producing carton pierre, composition, or any other material
where an accurate joint is required, and also for moulding old models that have been previously
jointed, or where it is undesirable to use gelatine for moulding. A jointed mould is simply a piece
mould on a small scale. The joints of the model, which are of course accurately jointed and w ith-
out being splaj-ed, are moulded separatel)-, the outside end of the pieces being splayed so that the\'
will allow the other part of the mould to draw when moulding or casting. The method of making
a jointed mould in wax is elucidated by Figs, i, 2, and 3 on illustration No. 90. Fig. i shows the
moulding piece of a soffit (in the naturalistic style) on a moulding board during the process of
making the mould. To make a jointed mould, first make a jjlaster piece at one end, as shown at
1", Fig. I. The piece is made about i inch higher than the surface of the model, and then
splayed down to the surface so as to allow it to draw ; the piece is raised so as to give it a bed and
thus prevent it moving in the front part of the mould. Joggles are sometimes sunk on the piece
for the same purpose, but the raised method is best for this work. The ends and sides of the piece
are also spiaj-ed. As the ground of an ordinary moulding piece is not wide enough to admit of a

Surface IVax Moulding.

sufficient width for the plaster piece and a rim for the front piece of the mould, the ground at the
ends must be extended temporarily with plaster before the plaster pieces are made. The size and
form of one end of the ground, before it is extended, is shown at G. Having made the two end
plaster pieces, fix the plaster side fence, S, on one side, and then the clay fence, c, on one end ;
repeat this on the other side and end. It is now feady for being moulded in wax in the usual way.
Fig. 2 shows a cross section of the mould on a moulding board, and Fig. 3 shows a side section
at one end of the mould ; the dotted surface shows the section of the plaster piece. When casting,
the mould is filled in with the desired material, and when set the mould is turned over and the
front or main part of the mould taken off, and then the end pieces are withdrawn, thus leaving the
jointed cast. The sides can be jointed in a similar way.

To Make a Surface
Mould. — Occasionally a few
circular casts of enrichments,
of the same design as used
for straight parts of the work,
are required to fit a ground
circular on section, such as a
soffit enrichment in a vertical
moulding on a coved ceiling,
or on the intrados of an arch.
The circular casts are readily
produced by the aid of a sur-
face mould. A surface mould
is somewhat similar to a front
mould, but with the excep-
tion that it has no rims, the
want of which enables the
mould to be bent to any
desired section. The method
of making a surface mould
is elucidated on illustration
Xo. go. This shows the
moulding piece of a soffit (in
the naturalistic style) on a

moulding board during the process of moulding. To make a surface mould, lay the moulding
piece as used for straight work on a moulding board as shown at Fig. 4. After this fix the
plaster fence on the ground, G, of the moulding piece, and against the side of the model as
shown at S ; then fix an end fence in a similar way against the end of the model as shown at E.
Repeat this on the other side and end. The model, or rather its surface, is now ready for moulding
with wax, which is done in the usual way. It will be seen that by fixing the fences against the
sides and ends of the model instead of fixing them against the sides and ends of the ground of the
moulding piece, as done for a front mould, that only the surface of the model presents itself for the
wax mould. After the wax is poured on, the moulds should be " bled," or the deep parts scooped
out, so that the sunk parts will make a rough kind of a joggle for a plaster case which is used to
keep the mould in position after it is bent. After the mould is taken off it is laid face downwards

No. 90.— Fig. i.— >r.\KiNG a Jointed Wax Mould.
Fig. 4.— Making a Surface \Va.\ Mould.

258 Plastering — Plaiit and Decorative.

on a circular <jround wliich is made to the desired curve. Tiic mould is then pressed dow n until it
fits the circular ground, and then a plaster back is formed on the mould so as to keep it in position.
The mould with its plaster back is then turned over and laid on a bench, and then jjlaster or wood
fillets or rules are fixed at the sides and ends so as to form rims to the mould, after which it is
ready for casting. Another way for bending and using the mould for casting, which is useful for
small work, is effected b)- making the mould without a plaster back, and then la\-ing it on its back
while still pliable, on a circular ground, made to the reverse of the proposed section. Wood or
plaster rules are fixed against the sides and ends of the mould so as to form rims. The mould is
then filled in while it is lying in the reverse circular ground. It will be understood that the mould
must be in this position e\ery time it is filled in. A cross section of the mould and cast is shown
at Fig. 5. The dark part is the wax, R, K are the rules which form the rims of the mould, and the
dotted surface indicates the jjlaster cast.

To Make a Front and Back \\'a.\ Mould. — Front and back moulding with wax is a
method generally employed for moulding models that are perforated, such as top-leaf running
ornaments or ornaments for co\ecl members in cornices, also for ornaments that are splayed on the
edge, such as a top leaf a patera, or a small rosette. A front and back mould consists of two jDieccs,
as its name implies. The model is backed up with cla)' to divide it into parts, and form a ground
for the first or front piece. The front piece, of course, forms a ground for the second or back piece.
The accompanying illustration (No. 91) elucidates the method of making a front and back mould.
To illustrate the method a perforated cove enrichment, as shown at I'ig. 1, is taken. This shows
the model on a moulding board. .^ is the section. This enrichment is about 5 inches wide, and with
the design repeated three times, is about 12 inches long. Fig. 2 shows the model with the ground
fence and a part of the side fence ready for pouring on the wax for the first mould, o is the ground
fence, J, J are two of the four joggles, s is the side fence, and C is the end fence. Only one
side and end fence is shown, to allow the section of the ground fence and the j<;ggles to be
seen more clearly. The method of " backing u|j " the model and forming the fences is as follows : —
First fill up the perforations in the model with moulding clay, pressing it in from the back with
the fingers until it is flush with the back surface. After this, lay the model on a moulding
board, and back up the sides and ends with clay, so as to form the " ground fence " all round the
model, and in a line with the various curved edges of the foliage and bands of the enrichment. This
is the most important part of the process, for unless this fence is made in a line, and flush with the
line or edge which divides the front and back sections of the model, the front piece will not draw,
and vice versa. For instance, if the fence was made below this edge, the front piece would not draw;
and if made over the edge, the back piece would not draw. It maj- here be mentioned that where
the profile extends over the centre of the sides of a model, such as the outer side of a top leaf the
fence must be made as far up or down at this part as will allow the front piece to draw, the remaining
])art of the profile being of course made in the back piece. The clay grounds in the perforations,
which were pressed in from the back of the mould, are made flush with the edges in the same wa\- as
u.sed for the outside part of the fence. It must be clearly understood that the claj' when smoothed
off is not left quite level with the edges of the model, but that it is kept nearly y\f inch below
the edges to allow for the wa.x shrinking, also to form a margin at the edges on the casts, to act as a
guide when trimming and jointing the casts. Wa.x that is soft in nature is liable to shrink when
cold, therefore if the fence was flush with the edge, the mould would form a seam on the profile of
the cast, which would distort the outline of the foliage after it was trimmed off. The surface of the
ground fence is made fair and smooth with a " small tool " and a soft wet brush. The points of

Front and Back Wax Moulding.

259

one's fingers are most useful for smoothing the clay grounds in the perforations. These surfaces are
finally smoothed with water, not oil, as already mentioned. The sides of the ground fence at the
outsides of the model should be made level, and not follow the section of the model. Level or
square sides give a better bed for the back mould, and a more effective bearing for easing the mould
when casting. If the sides were made circular, or to the section of the model, the edges of the back
mould would be thin and sharp on the sides, which would render them weak and easily distorted,
and being circular, would make a poor bearing for easing the mould when casting. The width of the
sides of ground fences varies from i inch to \\ inches, according to the size of the mould. Narrow
sides do not give a good bearing for easing the mould when casting, and they soon become distorted,
and prevent the front and back pieces fitting close together. A width of i inch will be sufficient for

Xo. 91.— Making .\ Front and Back Wax Mould.

this size of mould. Having smoothed the ground fence, cut joggles on each side of the fence, as
shown at I, J.

Joggles should be large in surface and low in depth. Joggles that are small in surface and deep
in depth form weak joggles in the back mould. The sides of this mould being I inch wide, the
joggles should be about 2} inches long, f inch wide, and ^ inch deep. A slight splay about \
inch must be made on the sides of the joggles to allow the corresponding ones in the back piece to
draw. Joggles with an excessive splay cause the pieces to slip, or " ride," as it is termed in
plasterers' parlance, when casting. After the joggles are finished, fix the side plaster fence, S. on the
ground fence, keeping it sufficiently high for the desired thickness of the front piece. The thick-
ness of a wax mould should not be less than \ inch at the highest points of the model or the
grounds of the model. Then fix the clay fence, C, on the end. Repeat this on the other side and

26o

Plastering — Plain and Decorative.

end. The surface of the mould is now brushed with water, and the wax poured on, laUiiii;
care to pour it on at the lowest part of the ground fence, as at X, and following on until all the
surface is covered, and to the desired thickness. The section of this model being circular, the
wax will be about 2\ inches thick at the centre of the section, therefore to render the piece more
pliable, it should be " bled," as already described. When the wax is cold, turn the piece with the
model over, and lay it on the moulding board, and clean off the clay. This done, brush the surface
of the model with water, and the wax with " clay water," and fix the side fence round the front
piece. It is now ready for pouring on the wa.x for the back piece. It will be understood that the
clay water on the wax must be moist while the wax is being poured on, otherwise the wax will
adhere to the front piece, and spoil both the front and back pieces. Fig. 3 shows the front piece, \v,
with the model, and one of the side and end fences, .s and c respectively. For large moulds,
or where the model is extra thick, a hole in the middle, or one at each end, is formed in the back
piece to enable the cast to be more easily pressed out. These holes also allow e.xcess plaster to

■ ■ ^^ ' " t^^^^i t i l

ruj2.

No. 92.— Makint. a Moulding Piece from a Front anh Back Mould.

exude when casting. The mould may also be filled in b)- pouring the plaster in the holes. The
holes are formed by fixing clay dots on the back of the model before pouring on the wax ; one is
shown at D. The wax for the back piece should be poured on at X. Wax should always be poured
on an original from left to right, to allow the worker to see the work better while pouring the wax
on. The front and back pieces are now taken off the model, washed out, and dried ; then it is ready
for casting. Before casting the ordinary cast work, it is necessary to cast an original or moulding
piece for making more moulds, as is generally required, or for future purposes, so as to save the
backing up and making ground fences, which would entail unnecessary e.xpense. The method of
making an original of this kind is as follows: —

To Makk a Moulding Piece fro.m a Front and Back Mould.— The method of
making a solid moulding piece — commonly called an original — from a back and front mould,
as shown in the previous sketch, is elucidated in the annexed illustration (Xo. 92). To make
the original, first oil the back and front pieces carefully, and lay them side by side; then gauge

IVax Piece Mouldhig. 261

sufficient plaster to fill in both parts, also a thickness of about \ inch over their surfaces. After
pouring on the jslaster and brushing it carefully, so that the work will be free from "blubs,"
level the top surface with a gauging trowel, keeping the stuff a full \ inch above the uppermost
surface of each piece, and regulating the thickness bj' viewing the ends. This is shown at Fig. i.
|- is the end section of the front piece, and B is the end section of the back piece. The dotted
surface indicates the plaster. Now take up the back piece, turn it over and lay it on the front piece,
and press them together until the soft plaster in both pieces is well united in one body, and not less
than I inch thick. After this clear off any e.xcess stuff that may e.xude beyond the sides and ends
of the two pieces. The sides and ends must be kept flush and square with each other, so as to
ensure uniformity in the sides and ends of the original and the subsequent moulds. When the
plaster is set, place the work in water for a few minutes to stop the suction of the plaster, which
enables the front and back piece to be taken off the original more easily. The complete original
is shown at Fig. 3. Moulding pieces can also be made in two'parts, one for the front mould and
one for the back. This is done b>- filling in each part of the mould as described above, and then
floating the upper surfaces of each piece separately.

Wax Moulding Pl.^QUES.— When moulding plaster casts of medals, .seals, or delicate plaques,
they should not be soaked in water, but set in a flat tray, the water jjoured gently in at one side until
it reaches within i of an inch from the top of the cast, and so left to gradually soak through.
When sufficiently damp, the face of the cast will appear moist and shiny. It is then taken out and
moulded in the usual way. This avoids the o\-ersoaking and spoiling the face of the cast by
brushing. This plan may also be used when moulding with sulphur.

Wax Piece Moulding. — Lea\-es or other enrichments having perforations, or undercut at
the backs, are moulded in two pieces, one piece for the front and one for the back. This is called a
front and back mould. If moulding a leaf, the eyelets and perforations should be plugged up with
clay before it is laid on the moulding board. It is then backed up and bedded all round with clay,
keeping a wide margin, not less than i inch, to give a good surface for pressing the fingers on in
easing the mould. A narrow margin soon gets distorted, and prevents the pieces fitting clo.se. The
surface of the margin should be kept ^^ of an inch below the edge of the face line of the leaf.
This is to allow for the shrinkage of the wax, and give a guide when trimming the cast. Make
the joggles wide and broad, but not deep. Narrow and deep joggles soon get out of order.
Wood joggles about \ inch by |^ inch thick, and | inch long, and then slightly tapered (to facilitate
their drawing), are sometimes used when wax piece moulding. The tapered end is inserted about
\ inch into the clay margin or fence, thus leaving a projecting joggle when the wax is poured on
and the cla)- taken awa}-. The joggles must be brushed with a solution of clay before pouring on
the other part of the mould. Owing to the brittle and porous nature of wax, the joints of wa.x
pieces cannot be cut to the desired form, nor with a smooth surface, therefore the clay fences must
be formed fair and smooth for each piece. Each piece should be allowed to be cool and hard, and
then brushed with clay water before the adjoining piece is poured on. The method of wax piece
moulding a modillion or block is nearly the same as given for plaster piece moulding a block. The
only difference is that the fences must be made to the correct form as alread)- mentioned, and that
back fences are fixed on the side fences to confine the wax to the desired position and form. Other
forms of models are wax moulded on the same principle.

Chasing Wax JMouLDS. — Wax moulds ma\- be impro\ed by sinking stems, or other parts, where
the clay model has been distorted. The ground or surface of soffit moulds, or other enrichments,
having a rough surface, can be made smooth and true b)- paring the projecting rough parts ofif with

-^- Plastering — Plain and Decorative.

a sharp chisel, then oilin-^ the wax surface, scraping with a fine drag, and finishing by poh'shing
w ith fish skin, Dutch rush, or fine glass paper. Wax burs, or projecting pieces caused by the
drawing of the wax where parts of the original are deep, are treated in the same manner.

Cl.W Squeezing. — A clay squeeze is used to obtain a temporary mould, or where it is
inconvenient to mould with plaster, wax, &c. The object to be squeezed is first dusted with French
chalk, or brushed w ith turpentine or paraffin oil, to prevent the cla\' adhering. The clay must be
well tempered, beat out in sheets, and rolled until it has a smooth surface. It is then pressed over
the work, using the fingers to press the claj- into the deep parts, and in close contact with the
object. Care must be taken to press the clay uniformly, so that there will be no blubs or creases
on the face of the squeeze. If the first ])icce of cla\' is not sufficient to cover all the work, cut a
clean square joint at the end of the pressed clay, and la>- another sheet of clay against the part
already dealt with, and press as before, continuing this until all the work is covered. Leave the
back of the pressed clay rough to give a key for the gauged plaster that is laid on to keep the soft
and yielding claj' in position. Float the back of this plaster case with a wet board, so that it will
lie straight on the bench.

Clav Piece Moulds. — A cla>- piece mould is used where parts of the object are too much
undercut to allow a .squeeze to be taken in one piece. After pressing the clay as described for clay
squeezing, back it up w ith stiffer clay, and cut the joints where the clay pieces are necessary, and
brush them with turpentine or paraffin oil before the next piece is laid. Continue this until all
the work is covered, and then make a plaster case to keep the clay pieces in position.

1'L.\STER Waste Moulding. — Plaster waste moulding is a method used for moulding clay
models on the round to obtain a cast or a moulding piece. A waste mould derives its name from
the fact that it must be broken or wasted before the cast can be extracted, whereas a number of
casts can be obtained from a piece or "safe" mould. If the clay is firm, it can be carefully coated
with thin shellac and then oiled. The shellac must be brushed on with a soft fine brush, so as not
to injure the modelling. This gives more freedom in moulding and less fear of injuring the
model when fixing the clay fences. The model should not be too dry, as the clay is a]jt to shrink.
If the claj' is of a medium firmness, it will not require shellac. An allowance must be made for
extracting the clay when the mould is done. This is generally done by making a .separate plaster
piece at the back part of the model, or where the work is plain, or by making the mould in two
halves, somewhat similar to a back and front mould. In moulding a bust, the general way is to
make a section in the back or crown of the head. First beat out a sheet of clay about I inch thick,
and then cut it into strips about i inch wide to form fences. Place a clay fence on the head, partly
on the crown and partly on the back, in the form of an oval, and as large as will admit the hand to
pass into the mould when e.xtracting the cla\' when it is made. If the fences are laid in an outward
slanting position, the piece will draw without taking it off to cut a splajed joint. The water for the
first coat of plaster is tinted with red or yellow ochre, to distinguish it from the second coat when
chipping the mould off from the cast. The tinted plaster is gauged soft and thrown on with the
hand or a spoon all over the mould (except the part inside the clay fence) until about \ inch
thick. The soft plaster may be put in jjosition by using a soft gauge brush, taking care not to
impress or distort the model. When the tinted gauge is set, brush the surface all over with clay
water to prevent the second coat from adhering to the first. The second (not tinted) coat is now
gauged, allowed to set a little, and laid about \ inch thick. When this is set, remo\e the clay
fence, trim the edge, and cut two or three sloping joggles; then brush the joint over with clay water.
Gauge as much plaster as will cover the oval part level with the top edge of the other .section. As

Plaster Waste Moulding. 2O3

soon as set, sprinkle the mould with water. The top piece is taken off by inserting the point of a
chisel at the joint and prizing, thus leaving an opening for extracting the cla>-. This process is
further aided by separating the mould from the stand, thus exposing a large opening underneath.
The clay is now carefully withdrawn from the interior of the mould by means of the hands and a
wooden tool, clearing the centre out first, until the clay gets thin, when it can be pulled from the
face of the mould. The interior is now washed with water and a soft brush to clear any small
particles of cla\-. The mould is then washed with soap water, and afterwards drenched with clean
water to clear out any excess soap. The crown piece is replaced and made secure with a string of
cord, or temporarily fixed with plaster. It is then ready for filling in. Gauge as much plaster as
will cover the face of the mould about \ of an inch thick, and pour it into the mould, and turn and
shake it so that the plaster will cover the interior of the mould. Return any surplus plaster to the
basin, and turn the mould again, then pour the plaster back into the mould, and as it will by that
time commence to set, it will cling to the mould more readily. Repeat this process until the cast
is sufficiently thick without being solid. The separation of the mould from the cast is an interesting
and delicate operation, and here the use of the tinted plaster is fully .seen, acting as a danger signal
to use caution when chipping the inner mould, to avoid chipping or otherwise injuring the cast.
With a blunt chisel and a mallet or light hammer chip away the outer or untinted coat of the
mould ; the thin tinted coat is then carefully and gently chipped or picked off until the cast is clear
and clean.

Another way for waste moulding busts or other models on the round, especially if casting an
original for jelly moulding, is to place the clay fence across the whole of the bust, so as to divide the
model into two parts (as in a back and front mould), keeping the front part the largest, so as to
have the joint nearest the back half. Begin fi.xing the clay fence from the bottom and work up,
carve the line of the fence to take the angle of the shoulders, then up to the edge of the ear until
the middle of the head is reached. Repeat the same process on the other side until the fences meet
on the top of the head. The clay for the fences should be beaten out in strips about I \ inches wide,
and laid on flat (they will lie better this waj- than if placed on their edge), and another layer of clay
is laid on until the fence is i\ inches thick, to allow a \ inch for jelly and 1 inch for the case when the
original is made. Care must be taken in la>-ing the fences not to impress the clay model. They can
be kept in position by pressing pins or fine French nails through the fence and into the model at
plain parts ; the small pin-holes can be stopped afterwards. When practicable, the fence should be
placed on the front half of model, and after the back half has been covered with the tinted and the
outer coat of plaster, the model can be laid on its back. This allows the face to be rpore easily
moulded than if standing upright. Three or four oblong joggles are now cut into the plaster margin
at each side, and brushed with cla}^ water. -A board or plaster ground is then fi.xed at the bottom
or end of the model to prevent the plaster running over, and to ser\e as a guide for thickness of the
waste mould. The other half is now made with the tinted and outer coat of plaster as before.
When it is set, the whole of the mould is well sprinkled with or immersed in water for two or three
minutes, to stop the suction of the plaster, and allow the mould to be opened and the clay extracted
more freel>-. La\- the mould on the bench with the back part of the model uppermost, and insert
three or four thin wood wedges between the joints, taking care to keep clear of the joggles. Drive
the wedges gently home with a hammer until the back can be taken off. This can be further aided
by extracting as much clay as possible from the opening at the end, and pulling it down until there
is little or no clay to offer a resistance to the back coming off. After the mould is separated, the
clay cleared out, and the back and front parts washed and soaped, an original is taken out of each

264 P/asfcring — Plain and Decorative.

half. After they are seasoned, they are ready for casiny and moulding. The advantages of this plan
w ill readily be seen by the practical man. The waste moulding, extracting of the clay, washing the
mould, filling in the original, casing and jelly moulding, are all done more easily and quickly when
in halves and Ijing flat than if done upright and on the round ; and there is no cutting the jelly at
the joints of the case, as must be done when moulded in one piece. This plan of making back and
front originals separately will also be found useful in wax moulding. Moulds or cases in halves are
best kept together when casting by making two rings of hoop iron, and placing one o\er each end
of the mould, and tightening b>^ means of wood wedges.

MOULDINC. KKOM LIKE. — Masks from the living and dead are often taken and used for models,
for busts in marble, bronze, terra-cotta, and plaster. Plaster casts of various parts of the body are
also often required as models. Pliny states that Lysistratus, the sculptor of Sicyone, was the first
to make moulds and masks from the living face, the date being about 328 B.C. Pliny's statement is
probably correct as far as he knew ; but as already mentioned, Dr Pctrie's recent discoveries prove
that moulding from life was in use about 1300 B.C.

The novice may begin by experimenting on the hand of a friend. First grease the hand,
smoothing the small hairs on the back of the hand, and lay it in the desired position on the moulding
board. If the position of the hand is hollow in the palm, support this with clay or rags. Then lay
a margin of cla\- round the hand and fingers. It is not necessary that this be made to "draw,"
because the flesh will yield when the mould is taken off. Make a few joggles in the cla>' by pressing
the end of the finger or a round tool into the clay margin, then gauge as much plaster with warm
water (to give less shock and .set quicker), and pour over the hand. As soon as this is set, reverse
the hand and grease the palm, cla\- water the plaster margin, and gauge more plaster with w arm
water, pour on, and when set, take the back and front off, and cast in the way already described.
Another way is to grease the hand as before, and plunge it into a basin of gauged plaster. When all
the surface is covered, place in the desired position, and as the plaster .sets, lay a strong thread on the
wet plaster along the hand and down the middle finger and o\er the point, passing it up the palm to
the wrist. Lay another from the wrist to the thumb. Now lay the remaining plaster all over to a
sufficient thickness, and when the plaster is nearly set, take the ends of the threads and pull them
through the plaster, thus making a piece mould. The hand must be kept perfectly steady. As soon
as the plaster is set, and the mould separated at the joints by the threads, the hand is released.
The divisions or sections may also be got by laying a wa.xed thread on the hand where required,
but before the hand is grea.sed, the waxed thread will adhere to the hand, if kept motionless.

The face may be next practi.sed on. Lay the living object in a recumbent position, then i)lug
the cars with wool and grea.se the face, co\ering the eyelashes and brows with wax, clay, or thick
pomade. The beard, &c., should be covered with thick clay paste. Then fi.x two quills in the
nostrils with wadding or fine wool for the purpose of breathing, and tie a towel round the head and
neck, close to the back of the ears, to prevent the plaster from running over the subject. Gauge the
plaster with warm water, and pour over the face. Another basin of plaster should also be gauged at
the same time with strong alum water (to make it set quicker than the first gauge). This is poured
over the first gauge, and as soon as it is set, and the first gauge nearly set, gently but firmly pull off
the mould. The object of having the second gauge to .set first is, that it will act as a case for the
first gauge, and enable the mould to be taken off just at the time the first is nearly set, without
pulling out any skin or hair that may get mixed with the plaster. If the first gauge was fairlv- set,
and anj- hair or e\-elashes got mixed with the plaster, the face or the mould might get injured when
being separated. The subject must look pleasant, and not laugh or make faces while the plaster is

Plaster Piece Moulding. 265

being poured on or while setting, or neither he nor the moulder will feel satisfied with the job. If
the subject is not impatient, he can turn round after the plaster is set, and before the front mould
is taken oiT, and have the back part of his head moulded. He can then have a cast of his full face
and head. The moulder is master of the situation, but he must be careful not to disturb or cover
the quills when he is pouring on the plaster, or the mould may be spoilt. Moulding separate parts
of the face, such as an ear, no.se, or eye, is good practice. Limbs, or even the whole figure, can be
moulded with plaster, and casts true to nature obtained. The ordinary way when moulding the face
is to use one gauge, but the plan described is best for preventing the hair from being injured. The
alum water should be tested by gauging a small pat of plaster, and a small pat of the first gauge
laid aside to judge the time of setting. If there are two moulders on the job, there will be more
time for gauging, and will also give more confidence in placing and keeping the subject in position.
It must not be forgotten to close the eyes of the subject before the plaster is poured on, but the
subject will probably do this of his own accord. It takes a more artistic treatment to open the eyes
in the plaster cast. The best plan to do this is to take a clay squeeze out of the mould, and open
the eyes and touch up the hair on the clay.

Plaster Piece Moulding. — A piece mould derives its name from being made up of a
number of pieces which placed together form the complete mould. Piece moulds are used for
reproducing metal, terra-cotta, concrete, wax, or plaster casts from original models that are on the
round or undercut, and where it is impracticable to mould them in one piece or in two pieces, such
as a " front and back " mould. If the seams formed by the joints of the pieces are carefully taken
off a cast produced from a well-made piece mould, it will be a fair facsimile of the original model.
Plaster lends itself more freel)-, and is more adaptable for forming a piece mould than either wax,
claj', sulphur, or metal. Its quick setting powers and unshrinkable and plastic nature, combined
with its fine and smooth surface, seems to be expressly designed bj' Dame Nature for this purpose.

Plaster piece moulding is about as difficult to explain as it is to learn. This subject, like most
if not all subjects appertaining to plaster work, has hitherto not been described, therefore I find
m>self on an untrodden path, with experience as my only guide. I will, however, endeavour to
explain, in simple trade phrases, the process from the beginning to the end. Piece moulding is
undoubtedly an important and useful branch of the plasterer's craft. A vast amount of piece
moulding is also done in terra-cotta work. A good piece moulder often obtains remunerative
employment in sculptors' studios, also in Government, educational, and surgical institutions, in piece
moulding antique figures and architectural examples for museums and art schools. Numerous and
important examples are to be seen in the South Kensington Museum. Up to the early fifties
plaster piece moulding of figures for sculptors was chiefly done by Italians. Since then British
plasterers have frequently been employed on this important branch of the plasterer's craft. T.
Worral, a Scotch plasterer, and O. Cullen, an Irish shop-hand, and several others have been exclusively
engaged on figure moulding in London. Plaster piece moulding is in daily use in plasterers' shops
for moulding vases, capitals, and similar models ; and in terra-cotta work for moulding, all kinds of
models, including figures, are solely done by British workmen. The greater employment of terra-
cotta, artificial stone, and fibrous plaster during the last generation has given a great impetus to
piece moulding, which has by the increased and more general practice enabled the native moulder
to equal his foreign rival in point of qualit}', and excel him in point of quantity. Plaster pJ-nre
moulding is an art requiring considerable practice and care. A piece mould is made in numerous
sections, so contrived that the several pieces can be taken off. one after the other, without fractur-
ing the model or the cast. The pieces are kept in position by the aid of a plaster case. In a few

266 Plastering — Plain and Decorative.

instances, where the pieces are lartje, few, and simple, no case is used, the pieces bein^ bound
together with string, wire, or hoop-iron. Roman joints or joggles are used to secure separate parts
of the mould together. A good piece mould is known by the cIo.se and firm joints, and bj- the ease
in taking every piece off the cast. It should be light but strong.

None but the best of plaster should be used for piece moulding. Where practicable, the piece
in hand should be completed in one gauge, so as to ensure equality in setting, swelling, and strength.
Several gauges are generally required to make a case. The addition of lime putty water to the
gauging water will improve the ultimate strength of the case. Lime putty water should not be used
in the gauges for the pieces, as it will cause the oil to peel and "fur" when casting. The moulding
piece or model should be clean and sharp. If otherwise, the mould and the resultant casts will be
dull and blunt. A piece mould can be taken from a plaster model in a "green" state, i.e., newly
made or unseasoned, but it is advisable to season it with linseed oil or with shellac, so as to stop the
suction. The method of .seasoning plaster models is precisely the same as described for seasoning
plaster moulds. When piece moulding a green model with plaster, use a solution of soap for lubri-
cating the surface, to stop the suction and prevent the pieces adhering to the model. Do not soap
all the surface at once, but only as much as will serve for the first and adjoining pieces, and so on
until the whole of the model is moulded. Stearic .solution, as already described, may be used for
this pur])ose.

The surface of models that are seasoned with linseed oil or shellac are generall>- oiled with
sweet oil. Suet solution is also an excellent compound for oiling models. It can be brushed on
so as to leave a very thin coat on the surface of the model. This is an advantage, as the thinner
the coat of oil is, the .sharper and truer will the plaster piece turn out. Suet solution does not soil
the model, but tends to indurate it and season the plaster pieces. The joints should not be brushed
with oil, as this clogs and makes wide joints. Brushing them with soap solution not onlj- prevents
cohesion between the pieces, but also enables close joints to be made.

Besides the ordinary shop moulding knives, a "moulding hammer" and a "joggler" are required.
Moulding knives are used for cutting the joints. They should be strong, long, and sharp, and of
various sizes, as described in Chapter XXI. A moulding hammer is u.sed for tapping pieces to make
them fit close to the model after they are trimmed, and for tapping them so as to loosen and enable
them to be taken off when they adhere to the model, also for tapping the case when it adheres to
the mould. A " moulding hammer " is shorter and heavier than a " lathing hammer," and has a
large flat head. This hammer being heavy and flat-headed, enables the piece to be more effectively
tapped and with less force than a light and narrow-headed hammer, and also with less fear of injuring
the piece or the model. A "joggler " is used for making sunk circular joggles. It is made out of an
old stiff putty-knife or an old chisel, the end being rounded off or shaped like a flat V drill. To use
it, place the point on the desired spot, and hold the handle between the hands, and then turn the
handle sharply backwards and forwards. For ordinary or temporary work, joggles can be sunk with
the point of a gauging trowel. A fine drag for levelling or smoothing the back of the pieces, and a
coarse drag for smoothing the case and cutting off sharp angles, are useful. .A dusting brush is also
necessary for cleaning the model and the pieces. Moulding boards or turnbats are also required, to
form a stand for the moulding piece, and allow it to be turned round when moulding the various
sides or ends.

Before beginning the mould, beat out a sheet of clay about \ inch thick, to make " fences " for
forming the pieces to the desired sizes and shapes. The oil and solution should also be prejjared
and tested before the work is begun. The term " oil," or " oiled," as used hereafter in describing the

Plaster Piece Moulding. 267

method of piece moulding, includes the use of soap and suet solutions, each being used for the
different parts and classes of work as already described.

When moulding an original or a model requiring many pieces, the size and shape of each piece
should be decided on and set out by the eye. In some models it is advisable to trace or faintly
mark the size and shape of each piece on the model with a soft pencil ; care being taken that each
will " draw," otherwise it or the model may be fractured. The size of the pieces depends entirely
on the class of work on hand ; it must be regulated, so that each piece ma>' " draw " freely. When
the size and form of the various pieces have been carefully thought out, and found practicable, pro-
ceed to form the pieces. If the model is on the round, such as a pedestal or a figure, begin at the
bottom, and work upwards. This method enables the first tier of pieces to support the pieces above.
Make a fence with a strip of clay about \ inch square, and to the required length. Lay the fence
on the model, and at the outline of the proposed piece, then oil the surface and lay the plaster as
already described. When the stuff is set, take off the piece, and trim the joint, and replace it on the
model, taking care that it fits close and true. A close fit may be obtained by gently tapping the
back of the piece with a moulding hammer. The pieces are got off the model also by gently
tapping with a moulding hammer, and then pulling the piece off in a direct line from the model, or
according to the angle of the part that is being moulded. This process is continued until the
whole of the model is moulded. The case is then made. A case for flat work is generally made in
one part, but for work on the round, such as a figure vase, the case requires to be made in two or
more parts, so that each will draw off the mould. The various parts of cases with their several
pieces are put together, and the whole bound with hoop iron, and tightened with wedges, or tied
up with strong string or sash line.

Piece moulds having many pieces require each piece to be numbered, or distinctive marks or
joggles to be sunk on the backs. This gives greater ease and speed in placing each piece in its
proper position in the case. The joggles also assist in keeping the pieces in position. The size of
the pieces depend on the size, form, and class of work in hand, and may vary from one superficial
inch to one superficial )'ard, but whatever size is made it must be regulated, so that the piece will
draw freely, and without fracturing the adjoining piece or the model. Small pieces are more easily
taken off the cast, because there is not so much suction as in large ones, but small pieces should
not be made just for the sake of making a larger number of pieces in a mould. The larger the
model, the larger the pieces, that is to say, if there are two models of the same subject, one large
and one small, the pieces on the large one would be proportionally larger.

Models are sometimes piece moulded direct from the original clay. For this class of work it
is necessary to indurate the clay surface by coating it once or twice with a thin solution of shellac
before moulding the model. Plaster piece moulds for the production of carton-pierre casts, such as
centre flowers, have the upper edges of each piece trimmed off from i to ^ inch deep, and when
the edges of the pieces come together, these form a flat V sinking, and a corresponding raised part
in the case when made. This keeps the pieces in position, and prevents them from being moved.
This plan is also useful for other mtjulds, but if the model is circular, or on the round, care must be
taken that they are splayed to allow the case to draw. When there are deep or thin parts on the
model, the plaster pieces are strengthened with perforated sheet zinc, or wire inserted in the plaster
before it is set. The last piece made is called the " closing piece," and as it requires no trimming, it is
not taken off until the case is made.

It is a good plan in large work to arrange the pieces in sections, in order to have a closing
piece in each section, because not being taken off until the case is made the}- make closer and

268 Plastering — P/niii and Decorative.

better joints than tlie jjieces that have to be taken off, tiiniined, and replaced. When tlie case is
made and taken off, the closint^ pieces are taken off first. This allows the other pieces to be taken
off in rotation or in tlie reverse order to that in which thej- were made. The closing pieces hav-e
a looped ring, commonly called an "eye," inserted in their centre before the plaster is set. The
eyes are intended to give a hold for pulling the pieces off. These eyes are made of copper or
galvanised iron wire, cut in 5 or 6 inch lengths. One piece is taken and bent over the tajjered
handle of a medium-sized tool brush until the ends meet. The ends are then twisted until there is
a stem about \ inch long, then bend the two ends in opposite directions, and at right angles to the
stem, pull the piece of wire off the handle, and the eye is ready for insertion. The eyes are inserted
in the centre of the desired pieces, just as the plaster begins to set, lea\ing the head or ring
projecting above the surface of the piece. Before making the case all the eyes must be coxercd
with cla}' to allow it to draw. This makes a sinking in the case, and when the latter is taken off,
the sinking is cut through, leaving a round hole about i inch in diameter. The piece is then taken
off the model, the clay cleared off, and a piece of strong vva.xed string about 12 or 15 inches long
passed through the eye, the ends being left about equal in length. The piece is then (jffcred u|j.
and the string passed through the holes from the inside, and tied on the outside over a small bar of
wood. The bar is made about 2 inches long and \ inch square, with the edges in the middle slightl)-
notched to prevent the string from slipping. The string is further tightened by means of a wedge.
When the mould is filled in, the string is untied and drawn out. The case can then be taken off,
leaving the piece on the model, while leaving the ]5iece on the mould when moulding, and on the
cast when casting. K)-es are also used for pieces that project at an angle, or an\' deep parts, where
the jjieces cannot be held in the case, or are liable to fall out, while the mould is being turned
o\-er.

When the joints of a piece are being trimmed, the angle should not be too acute, but there
should be just as much splay as will allow the ne.\t or abutting piece to draw. Joints cut with
too much splay give thin .sharp edges to the piece, which make bad joints, and are more liable to get
chipped than a nearh- square joint. The joints in inan\- moulds might be cut square, if it were not
for the swelling of the ])laster while the mould is being made, and also in the cast when casting.
This plaster expansion binds the pieces firmly together, and makes it difficult to take the pieces off
the mould and the cast. When the casts are made the seams cau.sed by the joints of the pieces
should be cleaned off while the work is "green." Seams are taken off with Dutch rush, fine
.scratch-tools, or fine riffles or files. They are further smoothed with a piece of fine flannel. Fish-
skin is an excellent material for smoothing large surfaces. It resists the effects of water and wear
for a long time.

To PlastKR Piece Mould a Modilliox.— Having committed the foregoing notes and
details to memory, the novice had better try his " prentice han' " on some simple model, such as a
plain modillion, or " block," as it is termed in plasterers' parlance. The method of piece moulding a
block is elucidated in the accompanying illustration (No. 93). Fig. i shows the original or moulding
piece of a block. B is the block, and G the ground of the moulding piece. Having beaten a lump
of clay into a sheet, cut a few strips from 2 inches to 3 inches wide to form fences for the upright
parts, also cut a few strips about i inch wide for the top fences. One edge of the narrow strips
should be cut on the slant, to give a splay to the ])laster piece which is to be formed against it.
The end pieces of the mould are made first, one at a time (a smart and efficient workman can make
two in one gauge), the sides next, and the top last. Cut one of the narrow clay strips to the length
of the end of the block and lay it on one end, keeping the slanting cut outwards and in a line with

Piece Moulding a Modillion in Plaster.

269

the arris of the block as shown at T, Fig. 2. After this, cut one of the wide clay strips to the desired
height of block, including the top fence, and fix it on the side and to the arris or mitre of the block,
and at an angle of 45 degrees, close up to the arris of the block. Repeat this on the other side, then
cut them in a slanting form, so as to leave them about I inch wide at the top and in a line with the
ground, as shown at .S, S. When fixing the clay fences, take care that the arris of the block is neither
covered nor left too much exposed, because if it is covered the piece will be short, and the next piece
will project over the arris and damage it ; and if too much is exposed, the piece will get over it with
the same result. This is an important part in piece moulding, and if the clay fences are carefully
put on at the edges and proper slope, the joints will not require much trimming, and there need be
no fear of fracturing the original or the piece when moulding or the cast when casting. This
applies principally to arris or undercut work, and where it is not advisable to take off the piece to

Fig 2

Fig 3

Fiq. 5.

Fig. 6

No. 93.— Plaster Piece Moulding a Modillion.

trim the joint, but for general work the clay fences may be placed about ,\ inch outside the line
or pencil mark of the proposed joint. The excess plaster is then cut and trimmed to the true joint.
A joint well trimmed with a good knife makes a truer and closer joint than if made with clay.
Still cla}- is indispensable to form a fence and a rough joint. Joints should not be cut at too great
a slope, but just splayed sufficiently to allow the piece to be drawn off the adjoining piece or vice
versA. The surface of the piece to be moulded is next oiled, and then the plaster is gauged and
laid on with a small gauging trowel or a spatula. If there are deep places or angles on a model,
the soft plaster ma)- be slightly spread into the interstices or angles with a tool brush, but the
plaster should not be dabbed in with the brush, as when the brush is drawn back after
each dab it draws away a portion of the plaster, leaving air spaces which cause the face

2-0 Plastering — Plain anil Decorative

of the plaster to be full of holes, which in plastic parlance is termed "blubs." If the plaster
is spread with the brush, the air is driven off, leaving a solid face. A solid surface is further
ensured b>' pressing the remainder of the plaster firmlj- and evenly into the space with the gauging
trowel, until the piece is made up to the required thickness. The side fences act as guides for the
thickness, and the top fence for the height. The back of the piece is made as fair and smooth as
possible before the plaster is .set, and any imperfections or ridges are made good, and cut or worked
fair with a drag after the piece is taken off.

The process of fi.xing the clay fences, oiling and filling in with plaster, is repeated on the back
end. While the plaster is setting, take off the first piece and trim the joints, and cut off the sharp
edges at each side formed by the side fences, so as to form a square side or " shoulder," to prevent
it sliding when in the case, and to form a stronger joint and interlock with the adjoining piece, thus
])re\enting the several pieces from falling inwards when in the case. A view of the piece when
trimmed and jointed is shown at Fig. 4. The form and use of the shoulders will be seen bj' the
sketch of the complete mould at Fig. 7. Having trimmed the piece, replace it on the original, and
keep it in position with a clay dot until the side pieces are made. The other end piece will now be
set and fit for trimming. This is done in the same way as for the first piece, taking care to form
the shoulders at each side without cutting the joint of the projecting part formed bj- the mitred part
of the cyma-reversa moulding. A view of the back end piece is shown at Fig. 5, and a plan of the
shoulders at Fig. 7.

The side pieces are ne.\t made. This is done bj- laying a narrow strip of clay on the top of
the block, and from the front to the back pieces, as shown at Fig. 3. F is the front piece,
and K is the back piece, and T is the top clay jjiece. The side is then oiled, and the plaster laid and
trimmed, and jointed at the top edge. This edge must be splayed to allow the piece to be drawn
out of the case. The spla\-ed edges form a rebate in the case, and prevent the piece from slipjiing
inwards. The form of the splaj-ed edge for this and the other pieces is shown in Fig. 6. The
thickness of the side piece is regulated at the top by keeping the outer edge of the soft plaster
parallel with the claj- fence, and by keeping the stuff flush with the ground, also by observing the
thickness at the ends. This will be better understood b\- viewing F"ig. 6, which shows a perspective
view of the original with the end and side pieces. The thickness of the side pieces can be accurate!}'
regulated by fi.xing a clay fence on both end pieces, allowing the ends of the fence to project to the
edges of the ground, and then cutting them to the desired slope at the ends, thus forming fences
and guides or bearings when filling in the side pieces. The other side piece is made in a similar
waj- as the first side piece. A distinctive mark or joggle must be made on the top edge of each
piece, as shown in F"ig. 6. These joggles are cut with a knife. Joggles gi\e a ready guide for
placing each piece in its own place in the case. They also prevent the pieces from shifting side-
ways in the case. It is advisable to make the joggles (or figures, as sometimes used) on each piece,
according to the order in which thej- are to be placed in the case when casting. Where there are
numerous pieces in a piece mould, this method saves time and annoyance in finding the \arious
parts and places. In this example the pieces are marked as a means of reference according to the
order in which they are made, but in practice the side pieces are placed first in the case, and then
the end pieces. If the end pieces were placed first, it would be very difficult to place the sides in
afterwards. This applies more especiallj- to the back end ])iece.

Making the case is the next and final part of the process. For small work like the present
example, the top piece of the model and the case is made together or in one piece, and in one
operation. A top or other piece that will draw, made this way, is said to be " made in the case."

Piece Moulding a Modillion in Plaster.

271

For best or intricate \vori< it is not advisable to make a piece in the case, because the case is more
liable to get injured than the pieces, and in the event of the case being broken while casting, a new
case can be easily made. But it would be more dilTicult to do this if it forms a piece or part of the
mould. The case for the present example need not be made to cover all the sides of the pieces or
extend down to the ground, but a space about i inch deep left clear, as indicated by the line at H,
Fig. 6. This space not only saves materials, but also forms a useful handling point for lifting the
case off when casting. The readiest way to form this space is by means of a fence, which is laid on
the moulding board and against the sides of the four plaster pieces. This fence may be made with
clay strips, or with thickness rules. This fence should also be made to the desired thickness of the
proposed case, as they also act as guides when making the case. If the case was required to extend
to the ground, and co\er all the surface of the pieces — as is necessary when there are several small
pieces in the sides of a mould — thickness rules must be laid around the mould and level with the
ground, so as to act as a fence to form the case level with the mould and as a guide for regulating
the thickness of the case. A part of a thickness rule is shown at D. Hand holes, to enable this form
of case to be readily taken off the mould when casting, are made by fixing a clay dot on the fence at
each end of the mould. The clay dots should be cut about 2 J inches long, li inches deep, and as
wide as the fence. Where the ground of an original extends beyond the plaster pieces, clay dots
similar to the above, and fixed on the ground and against the side and end pieces, can be used for
regulating the thickness of the case as well as for forming hand holes. Having fixed the space fence
at H, fix a small clay dot on the top of each of the four pieces, keeping them clear of the joggles.
The object of these dots is to form guides for regulating the thickness of the case. The holes allow
for dust to escape when brushing out the case. It will be seen that these dots are made and u.sed
for a similar purpose as described for the dot n. Fig. 3, illustration No. 91. After the case is
made, the dots are extracted. The original and the pieces are then oiled, and then the plaster
gauged and laid on. The plaster should be laid carefully, yet quickly. To do this, first pour a
little of the plaster over the work, then lay the remainder on bit by bit with a gauging trowel,
until the top and the ends and sides are formed fair with the trowel. The top surface is levelled
with a wet board, which is worked in a circular motion and before the plaster is .set. The sides
and ends may be further smoothed with a drag. The case and the pieces are then taken off the
original and dusted, and any blubs or defects made good, and the whole seasoned by coating with
shellac or oil as required. It is then read>- for casting. Fig. 7 shows the complete mould, with the
four pieces and the case C.

If the top or face of the block was moulded or ornamented, it would be necessarj- to form one
or more separate pieces. Assuming there is a top piece, first oil the original and the upper edges of
the side and end pieces, and then form the top piece. The thickness can be regulated by the joints
of the side pieces. As there is no joint trimming required, the top piece is not taken off, but the top
surface and edges are made fair and smooth with the trowel and drag. The case for this example is
made somewhat different to the first mould, where the top piece is formed in the case. For this
example, place a dot about i inch wide and i^ inches deep on each corner of the top piece, keeping
about \ inch from the outer edges. The object of these clay dots is to regulate the top thickness of
the case, and to allow the cast and pieces to be gentl>- tapped or pressed through the holes, also to
allow dirt or dust to be brushed out when casting.

To ]\lAKE A Model of a B.vluster.— Before describing the method of piece moulding a
baluster, it will be in proper working order to describe the method of making the model of a
baluster. The model of a baluster circular on plan is made in three pieces, and then they are fixed

2/^ Plastering — Plain and Decorative.

together. The bod)-, which is circular on jjlaii, is turned in a lathe, in a similar way as described for
scagliola columns. The top and bottom plinths, which are square on jjlan, are made out of a block
of plaster or in a mould (made by fixing four rules together). The latter is the easiest wa>'. Wiicn
fixing these parts together, take care that the plinths are level and square with each other, and that
the bod\" is central. A slight draft should be formed on the inner surface of the plinths to allow
the mould to draw. Models of balusters are also turned in wood. In this case the plinths and body
arc formed in one piece. Balusters that are square or octagonal on plan can be run in one piece.
This is effected b)- fixing running rules on a moulding board to the desired plan, then with a twin-
slippered running mould, running the various sides in an ui:)right position and in one operation. A
core .should be previously fixed on the board as a bearing for the plaster.

To Plaster Piece Mould a Baluster. — Plaster piece moulding a baluster is a simple yet
u.seful examjjle of moulding a model on the round or without a ground. The most difficult part in
moulding a model that is spherical in f(jrm, such as a bail, or one that is circular on plan, such as a
plain vase, or a round baluster, is to find the centre line, so as to divide the model into equal halves,

No. 94.— Plaster Phxe MouLDiNt; a Bai.ustek.

to allow the mould to be made in two side pieces. The centre line is used as a guide for forming a
fence for the first side piece. The top and bottom plinths of a baluster being square on plan, their
diagonal angles present read)- and accurate ])oints for obtaining the centre lines. This and
the method of piece moulding a baluster will be seen in the accompanying illustration (No.
94). A baluster is generally moulded in three pieces, one end piece and two side pieces. The
end piece, E, is made first, and on the top end of the baluster, as shown at Fig. i. This figure
shows an elevation of a baluster 2 feet in height ; T I' is the top plinth, and li 1' is the bottom
plinth, both of which are square on plan, as already mentioned. Before the end piece is made,
a joggle about i inch deejj should be sunk on the top of the model, as indicated b)- the dotted
line on the face of the top plinth. This joggle is made for a twofold purpose— first, to keep
the end piece in position while the side pieces are being made; and second, to form a sunk
joggle or key in the casts for fixing purposes. This joggle can be made either round or
square, but it should be irregular in the outline at one angle, so as to form a distinctive mark

Piece Moulding a Baluster in Plaster. ^73

to enable the piece to be readily replaced on the model after it is trimmed. Fig. 2 shows a plan
of the inner surface of the end piece, with the raised joggle, J. The end piece is made by fixing
a fence on each of the four sides of the plinth, keeping them flush with the sides and equal in height
to the proposed thickness of the piece. The thickness may vary from li inches to 2 inches,
according to the size of the baluster, but it should never be less than i i inches, so as to allow a
sufficient width for the joggles to be sunk on the sides, and the necessary strength requisite for its
purpose. Having fixed the fences, the model is oiled, and the gauged plaster poured on, and the
upper surface made level with the fences. After the stuff is set, the piece is taken off, trimmed, and
the joggles sunk. Joggles different in form or number should be made on each of the four sides, so
that the piece can be readily placed in its proper position in the mould when casting. They should
also be well defined in depth and outline, so as to form a strong joint with the side pieces. A joggle
that has a broad surface and low depth will form a stronger joggle in the adjoining piece than one
that has a narrow and deep surface. It will be seen that these joggles constitute the only means of
supporting the piece in the mould, hence the necessity of making them strong. In some districts
the end piece is not made as a separate jMece, but it is made in a case, the latter being also used to
hold the side pieces in position as a substitute for the bottom hoop, but this method is not so .safe
as the hoop and wedge. The model with the end piece is now laid longwise on a moulding board,
keeping two of the angles of the plinths vertical, and then supporting and holding the model in
position by inserting a block of clay at the angles, as shown at B, H, Fig. 3. Two similar blocks are
inserted at the top end, taking care that they are long enough to .support the model and the end
piece. These clay blocks are also used for supporting the two wooden rules, R, R, which form a part
of the side fences. These rules vary from i A inches to 2 inches wide, according to the size of the
baluster or required strength of the mould. These fence rules must be fixed exactly in a line
with the arrises of the top and bottom plinths, and level crosswise with each other. The spaces
between the rules and the outline of the model is made up within \ inch of the upper surface of the
rule with bits of old plaster, wood, or clay, and then gauged plaster is poured on these rough parts.
The surface is then made smooth and flush with the rules by the aid of a small joint rule, using
the fence rules as bearings. It will be seen that this process forms a fence at each side, true to
the centre of the baluster.

The formation of joggles for the side pieces is the next part of the proce.ss. ,-\s it is difficult
to sink joggles in the wood rules, it is better to make raised ones. This is clone b\- cutting blocks
of clay, each about 2\ inches long, li inches wide, and f of an inch thick ; then place two on each
of the fences, as shown by the four j's. An angle iron for each end is cut to the desired length and
bent to the angle. Angle irons are used to strengthen the angles of the mould. They are inserted
about ). inch from the ends of the side pieces. The form of one is indicated b\- the dotted line on
the end of the side piece at I, Fig. 4. The model and fences are now oiled, plaster poured on, and
the angle irons inserted. The sides of the piece are of course regulated by the edges of the side
fences, also the thickness at the angles, and the ends, are regulated by viewing the end of the model
and the end piece. The thickness and form of the piece can also be regulated by fixing a wood or
plaster fence at each end of the model. The form of one is shown at K, Fig. 4. The angles are
squared off so that the pieces will lie steady on the bench while being oiled. The side piece,
with the model and end piece, is then taken up, turned over, and laid on the moulding board, as
shown at Fig. 4. It is then dusted, oiled, the gauged plaster laid on, the angle iron inserted, and
the sides formed, as described for the first piece. This done, the pieces, are taken off the model,
and any defects made good, and then they are ready for casting.

2/4 Plastering — Plain ami Decorative.

A baluster square <in plan, called a "square baluster," is piece moulded the same way as
described for the circular baluster. Octagonal balusters generally require four side pieces, but if
the sides of the baluster are panelled, eight pieces will be required, luiriched balusters require more
or less pieces according to the design. The pieces are made on the same princij^lc as described for
" piece moulding a vase." Cast-iron m(julds have been used for casting Portland cement balusters,
but unless for very large quantities their price is prohibitor)-. " Sjjence's metal " has also been
used for making piece moulds of balusters, but although suitable for some moulding purposes, it
is too brittle in nature for large and heavy work of this kind. An improved metal, made on
Spence's princij^lc, is well adapted for making [)iece moulds for casting Parian or other white
cement balusters.

Duplicating Piece Mould.s. — If a number of moulds be required, they .should be duplicated
by moulding and casting, instead of making each piece. To duplicate the mould, take a moulding
piece out of each piece. To do this, place one of the side pieces flat on a bench, and mould it. An
end section of the i>iece is shown at Fig. 6. The dotted line indicates the section of the cast mould.
After this, lay the mould in a similar way, and cast as many of the side pieces as required. The
other side piece is duplicated in the same waj-. An end section of the mould is shown at Fig. 7.
The dotted line indicates the .section of the cast of the side piece before it is taken off the mould.
The end pieces are made by placing two side pieces on the original model, and after fixing them
w ith the hoops and wedges, filling in the \acant space with gauged plaster, repeating this until the
required number of pieces are made, thus duplicating the complete piece moulds. The end pieces
can also be made by piece moulding the first one. This is done in two pieces and a case. The first
piece is made from one diagonal angle to the other, similar in form to the end section of the side
pieces. The other side is of course the same in form. A case is then made over the two pieces,
thus completing the mould. A similar method of duplicating the pieces of a piece mould, whether
plaster, wax, or suljjhur, ma)' be ad\'antageously emplo)-cd for modillions, caps, and manj- other
plastic purposes.

Casting Balusters. — The moulds, which have been previousl)' seasoned, arc opened and
laid on a bench, then the pieces are oiled, and then placed together on end (with the end piece at
the bottom) en a casting board or a bench, as shown at Fig. 5 on illustration Xo. 94. The side
pieces, with the end piece, are held together with a square hoop made of hoop iron at the top and
bottom, as H, 11. The hoops are tightened by means of wedges, as \v, \v. The mould is now read}-,
and in its proper position for filling in. After the mould is filled in, the cast is ruled flush with
the edge of the mould, and a rough joggle formed in the end of the cast for fixing purposes.

To Plaster Piece Mould a Vase. — A vase is chosen as a final example of piece moulding,
as it presents several features for illustrating various parts of piece moulding that are used for other
models that are "on the round," such as figures, busts, fountains, &c. This form of model also
serves to illustrate the method of piece moulding models " on the flat," such as panels, centre
flowers, medallions. The profile of most vases are partly oval or in the form of an egg-cup. The.se
are generally moulded so that the case can be made in one piece. A vase with a profile that is
somewhat square and projects near the centre is herp given, so as to illustrate the method of
moulding a model on the round that necessitates the case to be made in two parts or halves. A
vase consists of two parts, the " foot " and the " body." The foot is generally cut off the body of the
model, and the two parts moulded separately, and when the casts are made thej- are fixed together.
This is the best way where the foot is high or narrow, or too weak to carry the body until fully set,
as there is less chance of breakage than if the vase was cast in one piece. For large or heavy work

Piece Monldiiig a Vase in Plaster.

275

the foot and body are best moulded separately, so as to facilitate the ease of casting. and
handling. If the model is of average size, or the foot short and sufficiently thick to give ample
strength to carry the body while being cast, the vase should be moulded as a whole. The latter
method is used for the present example, as shown in the accompanying illustration (No. 95), which
gives the elevation of a vase during the process of being piece moulded ; one half is moulded, and
the other is in progress. The vase is about 2 feet 6 inches high, and 2 feet in diameter at the
" lip" or top. The darts at s indicate the height of the foot or stand, and the part above is the
bod}- of the vase. The mould for this form of vase is made in two equal sections, one for each
vertical half of the model. A case for each section is also required. A section with its case is made
first for one-half of the model, and then the section with its case is made for the other half, and

No. 95. — Plaster Piece AfouLDiNG a \ ase.

against the two ends of the first section, as indicated by the illustration. Xos. i H to 7 H are the
ends of the pieces at one side of the first section of the mould. The ends of the pieces at the other
side are of course covered with the end pieces of the second section of the mould. The sketch
also shows the inside elevation of the rim piece with its ends, R, K. This piece extends around the
first section from end to end, and is made in one piece so as to keep the lower pieces in position.
This is further secured b>- means of joggles which are made in each of the top row of the adjoining
pieces, one of which is indicated bj- the dotted line at 7 H. The rim piece is made to lay over
the lip or top of the model, so as to give a ground for regulating the thickness of the casts while
casting. The sketch also shows both ends of the case for the first section with the joggles, j, j,
which are used to hold the case of the second section in position.

2/6 Plasteyiiig — Plain a)id Decorative.

To piece mould the vase, first divide the circumference into two equal parts, and from these
points make a \ertical line on each side of the model. These vertical lines are used as guides for
making the first and second sections of the mould equal, so that the case for each will draw off
freely. The vertical lines should be made where there is the least amount of ornament, as it is
easier to clean off seams on a plain surface than seams on ornamental part.s. Fewer and larger
pieces can also be made on plain parts. Large pieces lie better than small ones at the ends of the
cases. It will be seen on the sketch that the grotesque face, being plain and flat, requires only two
pieces at each side, whereas the female face, being prominent and more fully enriched, requires six
pieces for the half or side. Having made the vertical lines, proceed to piece mould the first half of
the model. The method of doing this is similar to that used for the second half with the exception
that clay fences are fixed on the model at the vertical lines to form the ends of the pieces of the
first section of the mould, whereas the end pieces of the second section are made on the end pieces
of the first section, as shown by the illustration. Figs, i II to 7 M are the end pieces of one side
of the first section, and the pieces, Nos. i, 3, 4, 7, X, 15, and 17 are the end pieces of the .second
section which are made on the end pieces at the other side of the first section. The method of
making the first section of the mnukl w ill be gathered from the description given for the second
section, which is as follows : —

Begin at the bottom of the model and work upwards, so that the lower pieces w ill support the
upper ones, until the case is made. Also work from the vertical joints towards the centre of the
model. To make No. i piece, first fix a narrow clay fence on the joint of the first case, following
the contour of the piece in the case, then fix a vertical clay fence on the model, and then fix a top
fence to connect the two vertical fences. The position of these fences will be seen by the dotted
lines on the other side of the model. U indicates the narrow fence, v the vertical fence, and t the
top fence. A narrow fence is made at this part, because it is only used as a guide for forming the
thickness of the piece at this side. If made wide, there would be an e.xtra thickness of plaster to
trim off to make the piece flush with the back of the adjoining piece. Wider fences are used at the
vertical and top sides, as they form the joints as well as the thickness of the piece. The dotted
lines u and T will also serve to illustrate the method of forming fences for the first piece of the first
section of the mould. Take the dark surface, I 11, as a clay fence at the main vertical joint, which,
with the fences V and T, would form the complete fence for the first piece of the first section.
Having fixed the fences for No. i piece, oil the surface, fill in space with jjlastcr, and form the back
of the piece with a gauging trowel, and when set, take the piece off, and cut the joint at the case
until flush with the back edge of the piece in the case, and then smooth the back with a fine drag.
This done, cut a splay about \ inch deep on the upper and left hand edges of the piece ; the use of
these splays will be seen when the adjoining pieces are made. The \ertical edge at the case must
not be splayed but left square, to form a level or flush joint to allow the case to draw. After this
fix a vertical and top fence for No. 2 piece, and then fill it in as before. The back of this piece is
made smooth and flush with the adjoining piece by the aid of a drag. It is then taken off and the
vertical and top edges are splayed as before. After this fix fences for No. 3 piece, fill it in, trim
the back and splay the edges, as described for No. i piece. The vertical spla\s on the right-hand
side of the pieces which are near the main vertical joint of the mould must be made flatter than the
left-hand sides, so as to allow the case to draw. This method would of course be reversed on the
other side of the mould.

It will be seen that the splays form sunk V-shaped joints, as shown by the vertical joint
between Nos. i and 2 pieces, and the horizontal joint between these pieces and No. 3 piece. These

Piece Moulding a Vase in Plaster. 277

sunk joints form corresponding raised divisions in the case (as shown by the sketch), which assist
in keeping the various pieces in their proper positions in the case. V-joints are principally used for
piece moulds that are used for producing carton-pierre casts, terra-cotta work, or where stiff gauged
cement is used. The raised divisions prevent the pieces from moving, while these materials are
being pressed in the mould to form the cast. It will be seen that two pieces, Xos. i and 2, are
used for the half of this section, while only one piece. No. 3, is used for the half above. The reason
for this is, that the flutes on the moulding would not allow one piece to draw freely, and that No. 3
piece being on a plain part enables it to draw in one piece. The pieces Nos. 4, 5, and 6 are next
made in the order named, and in a similar way as described for the lower pieces. This part of the
model requires three pieces for two reasons — first, because the circumference is greater at this part
than below ; second, that this part being enriched, more pieces are required to allow them to draw
off the repeated ornament. It will be seen that the horizontal joints of Nos. 2 and 3 pieces are
made on plain parts, or near the centre of members of the moulding, but the horizontal joint of
No. 6 piece is made at the arris of a member. The former way makes better joints than the latter,
because the seams on the subsequent casts are more readily and truer cleaned off on the profile of a
member than a seam on an arris of a member. The top horizontal joint of No. 6 piece is drawn
this wa)' purposel}- so as to show the defect more clearly, also to show that a joint should always
be made to give sufficient strength at the edge of the piece. If the joint of No. 6 was made in the
centre instead of the arris of the member, the piece would be too weak at its upper edge ; this will
be better seen by comparing the full section of a similar piece at 3 H. It will be observed that the
thickness of the piece between the joint and the projection of the ornament is already too small for
practical use, and if made in the centre of the member, it would be still thinner, consequently
weaker and less useful. A stronger piece and a better joint would be obtained by making the
piece larger with the joint at the dotted line, between the darts 4 H.

Having made the third tier of pieces, the pieces from Nos. 7 to 14 are ne.xt made. This is done
in the order named, and in a similar way as described for the lower pieces. The joints of these
pieces should be made, where possible, on plain parts of the body, or at the arris of a scroll or
band, or where most suitable for the piece to draw at undercut parts of the model. It will be
understood that these items regulate the size and form of each piece, as mentioned in the notes on
piece moulding. It will be seen that piece No. 14 is in the centre of the pieces mentioned above.
The latter piece is made last, so as to form a " closing piece." A closing piece is made at the
centre of a series of pieces, so as to bind the surrounding pieces, and make closer joints. A closing
piece is not taken off until the case is made. The splayed joints are cut in situ. A closing piece
is sometimes used to support the surrounding pieces after the mould is made. When used for
this purpose, a wire eye is inserted in the middle of the piece, as shown. A " wire eye " is also
used for pieces that project in the mould to prevent it falling before the mould is filled in. The
method of using this is shown at M. Although not absolutely necessary for the piece x, the wire is
shown here, as being the best place for illustrating its use. The elevation of a wire eye is shown at
w. The method of making this has already been described. The fangs of the eye are inserted
into the piece before the plaster is set, leaving the eye protruding, as shown at M. The eye is
covered with clay to allow the case to draw. The clay should be a little larger than the projection
of the ring, so as to allow space for t>ing a string on to the ring, as indicated by the half circle.
After the case is made, a hole about \ inch in diameter is bored through the case with a gouge. A
string is then tied on the eye. The ends of the string are then carried through the hole in the case,
which arc in turn tied over a wood bar or wedge, which is laid across the hole on the outside of the

278 Plastcyim:^- -Plain ami Decora tiv(

case, as shown, thus jirevcnting the i)iecc from faUin<:j inwards. It will be understood that the piece
X and the case at M are taken for the time being to illustrate the method of using a wire eye. A
closing piece may also be made in the form of a " wedge piece," so as to act as a support for tlie
surrounding pieces to prevent them falling inwards or out of the case before the mould is filleil
in. This is effected by making the surrounding pieces first, and sjjlaying the joints that are next
to the proposed wedge piece inwards instead of outwards, as used for the other sides of the ]3icces.
The intermediate space is then filled in, and a wire-eye inserted in the middle of the surface, thus
forming the wedge piece. This piece is then tied with a string, and secured on the outside of the
case as already described.

The pieces Xos. 15 to 17 are next made, and in the order gi\en, and as already described, for
the other pieces. The top piece, No. 17, must be made to extend above "the lip," so as to form a
"shoulder piece" to form a bond with the rim piece. The pieces lettered from A to H are next
made, and in the order given. The jjiecc II is used as a closing piece, but without a ring. The
pieces I and j are ne.xt made in the order given. The joints of the lettered pieces are not splayed
at their upper edges, but are left square, thus forming " flush " joints, i-lush joints are generally
used for small work, also for pieces that have a deep projection in the case, or where sunk joints
would prevent the case drawing off" the pieces. The projection of the face in the centre of this part
of the model gives a good bed for the pieces in the case, hence the reason for making flush joints
at this |jart. Tlie fences for the next pieces to be made (Xos. 18 and 19) are shown at O and I",
respectively. The.se pieces being small, may be filled in with one gauge. After this a fence is
fixed across the ends of these pieces, and then the intermediate piece No. 20 is made. This done,
the piece No. 21 is made, the form of which is indicated bj- the dotted lines. It will be seen that
this piece comes over the moulding, so as to take in the back part of the centre and side scrolls,
which surmount the plain oblong panel. This enables the projection of the scrolls to have more
relief than if they were " stopped " down to be moulded in one piece. With the exception of a
piece for the oblong panel, this completes half of the second section of the mould. The other half
of the mould is made precisely in the same way.

The fences indicated by the dotted lines at U, V, T are used for the first piece. This is shown
when taken off to be trimmed at No. 22. The intermediate space at S is then made, and so on as
before until the whole side is finished similar to the other half. The plain panel, with part of the
scrolls, is then made as a closing piece. Joggles are then sunk on each of the top pieces, and then
the rim piece is made. This is made in one piece, as already mentioned. Joggles are now made in
the ends of the first case to receive the second case, which is next made, thus completing both
sections of the mould. It will be understood that the figures from i to 17 and the letters from A to
J are sunk on the backs of the pieces, to afford a ready guide for placing them in the case while
casting. The other letters and figures on the ends of pieces and the case are simply used as
references for describing the method of moulding.

Pieces that project on the model, similar to No. 4, are liable to fall by the force of gravitation,
and are supported until the case is made by fixing plaster dots on the joints, so as to obtain a
support from the adjoining pieces. These dots are oiled before the case is made, and after the case
is made they are then released from the pieces by tapping. Projecting pieces are also held in
position by the aid of wood props. The props may be removed while the case is being made, or
they may be left in and the projecting ends sawn off" after the case is made. Projecting pieces are
also supported by means of a "link," as shown at L. This link is simply a piece of rod iron, from
\ inch to \ inch thick, bent to the form of a half link or a half oval ring. It is bent a little less in

Casting Fases. 279

width from the points than the desired fixing points on the pieces. When fixing, it is then opened
a little and allowed to spring back on the fixing points. Links are also used for holding a piece in
position while the adjoining pieces are being made, so as to ensure true and close joints. A va.se
that is egg-cup shaped is generally moulded so that the case will draw in one piece. This is effected
by cutting the foot off, then moulding it and the body .separately. A rim piece is made first on the
top of the body, then both are inverted, and then the other pieces made, thus allowing the case to
draw in one piece.

Casting Vases.— When casting vases in Portland cement or fine concrete, the thickness of
the body is regulated by means of a wooden template, which is inserted on a pivot fixed on the
moulding board if the mould is open at both ends. If a separate mould is u.sed for the body, a
pivot is fixed in the centre piece at the bottom for the template to work on. The template may also
be formed to work in a hole made in the bottom piece. If the mould is open at both ends, the
template is made to work on the rim piece at the top and the case at the bottom. If the mould is
wide and low, so that all the surface may be got at, the cast can be filled in while the mould is in
an upright position, but the safest way is to fill the mould in by sections. This is done by laying
the mould on its side, then filling in about one-third of its circumference, and when set turn the
mould over so that another third can be filled in. This is repeated until the whole surface is
covered. The joints of each section must be left a little thinner than the proposed thickness of the
cast, so as to allow the following section to lap over and strengthen the joint. Moulds that are
made in two sections, similar to the example shown in illustration \o. 95, are more easilj- filled
in. Each section is laid foot to foot on a bench. They are then filled in, and when the material is
nearly set they are raised on end and placed together, and then secured at the foot with a rope and
at the top with an iron hoop, both of which are tightened by the aid of wedges. The joints are then
made good, and the thickness of the cast regulated as already described. The method of casting with
Portland cement is described hereafter.

Oiling Plaster Moulds.— Plaster piece moulds are generally oiled with a mixture of
Russian tallow and sweet oil. Lard with and without sweet oil is sometimes used. The addition
of paraffin oil to these oils renders them more soft, cleaner, and freer to work. Soft soap alone,
also mixed with sweet oil, is preferred for some purposes. Plaster being of a porous nature, and
containing a proportion of lime, is easily affected by soaps, fats, or oils. The fatty acids unite with
the lime and render the face of the mould and cast sticky. This causes dust to accumulate, and in
time to form crusts in the deeper recesses, which are difficult to remove. German plaster moulders
overcome this by the use of finely separated stearic acid. One part of stearic acid (or stearine) is
melted in a water bath, and about 5 parts of alcohol or benzine is added, in which it dissolves to
a clear solution. B)- shaking as it cools the acid will be obtained in a fine state of division, forming
a kind of magma with the alcohol. This is used for oiling the mould, and in a short time the alcohol
will evaporate, leaving a thin film on the mould, and allowing the cast to be readily taken out covered
with a thin imperceptible film of non-adhesive stearate of lime. This stearic oil is also useful for jelly
moulds. Animal oils develop acids, vegetable oils become gummj-. By the admixture of mineral oil
(preferabl\- paraffin) these qualities are neutralised. Temporary moulds, intended for two or three casts
onl)-, are not seasoned, but are thoroughly saturated with water and then oiled with a solution of soap.

Suet Solution. — Suet solution is an excellent compound for oiling models when plaster
piece moulding. It will also be found a ready and useful oil when casting in wax and sulphur
moulds. Suet solution is made by dissolving fresh mutton suet by gentle heat, then adding as
much paraffin oil as will keep it in a soft crcam\- state when cold.

28o Plastering — Plain and Decorative.

Soap Solution. — This solution, or soap water, is made b)' reducing soft so.iji u ith boiling
water to a creamy consistency. It is used for plaster waste moulding, also for the joints w hen
plaster piece moulding, and several other shop purposes. Soap water should not be used for
washing old or dry plaster moulds or casts, as it leaves a thin sticky film which attracts and retains
dust. They should be dry dusted, and then washed with warm water and wiped. They are then
ready for oiling.

Stk.\ric Impervious Solution. — This solution will be found u.seful when plaster piece
moulding, and for the moulds when casting special works, such as antique and classical figures,
panels, &c. By its use, sharp, clean, and white casts are obtained. A neutral soap of stearic acid
and caustic soda is prepared and dissolved in about ten times its weight of hot water. The
models and moulds are coated by being either brushed with or immersed in this solution.
B)- this process the colour of the moulds is not affected. It is rendered impervious, and permits
the moulds or casts to be washed, even with lukewarm soap water. Stearate of potassium is only
soluble in hot water. As already mcntioneti, soap water lca\cs a film on the surfaces of moulds,
which attract dust. The same difficulty is presented by plaster that has been impregnated with a
solution of alum and stearine. A .solution made with stearate of alumina in benzole behaves in the
same waj-. The plaster can also be made impermeable to water by washing it with a solution of
oleic acid in benzine. This is applied cold, and the casts must not be washed with soap water, as
it would take up the oleic acid. The best way is to wipe them with a cloth moistened with the
acid. The stearic acid and caustic soda solution gives the best results, and it may be used for
waterproofing plaster casts.

OlLlXd W'.vx Moulds. — The oiling of moulds is an important feature in the production of
clean and sharp casts. Oiling moulds is a simple thing, yet it requires attention to avoid waste of
oil, injury to the mould, and blunt and discoloured casts. Olive or sweet oil is generally used for
oiling wa.v moulds, and gives good results for general purposes. Russian tallow, lard, and mutton
suet is also used for oiling wax moulds as well as for plaster moulds. .Animal fats are too hard
to work freely. If they are thinned down by adding paraffin oil, as already described, they work
cleaner and more freely. The fats should be dissolved by heat, and then sufficient paraffin oil
added until of a creamy consistency. Chalk oil is also used for wax moulds. Moulds composed
of rich wax will yield a few casts without oiling by simply brushing with soap water and then
rinsing. Wax that has been seasoned by using a few times gets a certain quantity of fat or oil
incorporated through the oiling of the moulds, which is retained by the force of the water, and does
not require oiling for every fill-in. If they are oiled once a day they will yield clean and white
casts. New moulds after being oiled should be well washed with soap water to remove any
superfluous oil and ensure clean and white casts. Oil is often spoiled by being kept in open oil
pots ; a self-closing pot is made as follows : —

Ball Oil-Pot. — Most shop-hands will have noticed that the old method of dipping the oil
brush into an open oil-pot is a source of waste of oil, and that the open [)ot is a harbour for
dust and dirt. To avoid these evils I have introduced the " ball oil-pot," which, by means of a ball,
practically closes the pot. while allowing the oil to be obtained in regular quantities. It is simple
and cheap in construction. First procure an old sardine tin of medium size, and an earthenware or
glass ball. The diameter of the ball should be about double the depth of the tin, so that when
placed in the tin one-half of the ball will project above the lid. Now cut a circular opening in the
centre of the lid. The diameter of the hole is made slightly larger than the diameter of the ball,
so that it will admit the ball to revolve freely. The lid may also be hinged on one side, and

Gaiighig Plaster. 281

made with a clasp on the other, to allow the pot to be cleaned out when necessary. When the pot
is filled with oil, the oil brush is pressed on that part of the ball above the lid, which causes it
to revolve and take up a certain quantitj- of oil, and as the brush only takes up the oil that is on
the surface of the ball, it can be applied to the mould with greater regularity and more uniformly
than by dipping the brush into an open oil-pot, and overcharging it with oil, and swamping that
part of the mould where laid, thus causing unnecessary wear by dipping for the excess oil that is
lying in a bod>-, destroying the face of a delicate mould, and leaving the oil unevenly spread, which
obliterates the fine lines in the mould and causes blunt casts. The use of the ball oil-pot will be
found to effect a great saving of oil. It is also quicker, cleaner, and more regular and economical
than the old method.

Gauging Plaster. — Gauging plaster is one of the most common, but important tasks in
connection with plastering. Nevertheless very few know how to gauge properly, though it is a
simple operation. Gauging plaster properly is not only the primary but also one of the principal
parts of most plastic processes. Plaster should always be kept in a box, having a lid to keep out
dust and damp. The box should be placed on a stand about 2 feet high. This will save
unnecessary stooping, exertion, and time. Stooping and gauging out of a plaster sack is slovenly,
wasteful, and tiring. A "slush tub," as already mentioned, is also requisite. The water should be
clean and fresh. Dirty water impairs the strength of the plaster when gauged, also the whiteness
of the cast work. In order to avoid waste or extra gauging for one fill-in, the water should be
measured for repeated work. For this purpose, a pint measure should always be placed handy at
the water tub. Where practicable, the mould should be filled in with one gauge to ensure solidity
and equal expansion. This applies more especially to solid cast work, but in fibrous work, or when
the plaster is gauged with size water, this is not so important. The quantity of plaster used for
any special job may also be ascertained by measuring the water before gauging. It takes about
2 lbs. of plaster to l pint of water to make a gauge of medium stiffness. After measuring the
water into the gauge pot, lift the plaster with the hand, or with a small tin scoop, and lightl\- but
quickh- sprinkle it all o\er the water. Continue this until the plaster appears at the surface. When
all the water appears to be taken up, and there is no dry plaster on the surface of the water, it is
then quickly stirred up with a gauge stick for large quantities, and an iron spoon or a gauge brush
for small quantities. This method, if properly performed, prevents air bubbles and lumps in the
gauge. The desired consistency is also easily obtained, therefore no added water if the gauge is too
stiff, also no added plaster if the gauge is too thin, is required. Adding water or plaster after the
material is gauged weakens the ultimate strength of the plaster. This is caused by the extra work
which the plaster is subjected to by extra stirring or gauging. The stirring should be done quickly
but not long, because excessive stirring tends to kill the plaster. Excessive water and working will
destroy the setting and hardening of the best made and strongest plaster. It is a well-known fact
that many plasterers when finishing the stopping of the joints of cast work, and wishing to match the
white colour of the neat plaster casts, use neat fine plaster, and literally work it to death b)' con-
tinuous working and adding water. This is truly termed " killed stuff" Plaster gauged with clear
size water would answer equally well for this purpose. Size water retards the setting, and to a
certain degree hardens plaster, but no amount of size will make or keep an overworked plaster
strong. Even if the plaster is gauged quick and stiff with size water, it will become weak if
excessi\-el\- worked.

As already stated, the practice of adding more plaster to that alreadj- gauged is wrong, because
it creates additional heat and swelling, thus injuring the mould, and rendering the cast difficult to

282

Plastering— Plain and Decorative.

extract. It also tends to cause warpiny in the casts. Plaster for cast-work should not be gauged
too stiff; a thick creamy consistency, just sufficient to allow it to run freely into the intricate parts of
the mould being the best for obtaining solid and hard casts. Plaster swells and gives off more
of its latent heat if it is gauged thick, or in other words gauged with more plaster than the water
will readily take up. The extra swelling, as above .stated, makes it difficult to take a cast out of
the mould, and it is apt to burst a plaster mould. Clean pots and water for every gauge is indis-
pensable. Old or liquid plaster in a fresh gauge weakens the cast work. Lime water furs the moulds,
and causes the casts to adhere, and be difficult to extract. For a final example of the difference between
plaster that is gauged slowly, thin, and excessively worked, and plaster that is gauged quickly, stiff,
and sparingly worked, a practice of everyda>' work ma>- be cited. Many plasterers will have noticed
how hard plaster becomes that has been gauged by simply soaking in water. This is often done on
the blade of a trowel for stopping purpo.ses. If the plaster is not kept too long in .soak it will only
take up the minimum of water, or as much as will moisten it ; and as there is no stirring or working,
the setting properties are left free and undisturbed. Even if the plaster is left in the water for hours,
it will be found harder than a soft gauged or overworked plaster. The stiffer plaster is when
gauged, the denser and harder will be the resulting work. Plaster that has been gauged soft (i.e., with
an excess of water) is much more porous, and has consequently far less wear and durability in it,
than if it had been gauged stiffer. For fine cast work, plaster should not be gauged too stiff, other-
wise it is difficult to bru.sh it into the crevices of the mould, and it is also apt to burst the mould by
expansion. Expansion is greater in plaster that is gauged stiff than in plaster that is gauged soft.
Plaster is to a certain extent soluble in water. About i part of plaster will dissolve in between 400
and 500 parts of cold water. It will be seen from the foregoing that plaster should be quickly
gauged, moderately stiff, and sparingly worked for all plastic purposes where strength and dura-
bility is a desideratum.

USE.S FOR Old Plaster. — In shops where a large trade is done, the waste gauged plaster, old
cases, originals, grounds, and slush often accumulate in large quantities, and make a considerable
item in cost for cartage. The old dry plaster may be converted into a bastard plaster or Parian for
gauging coarse stuff or similar purpo.ses, by .soaking it in a strong solution of alum, borax, or
vitriol, then calcining in an oven, and afterwards grinding. Old plaster is sometimes u.sed to fatten
mortar by grinding them together in a mortar mill. Slush (the thin killed plaster washings of
gauge pots) may be turned to advantage b>- converting it into " hearth blocks " for whitening hearths,
jambs, &c. This is done by pouring off the excess water and mixing the sediment with coarse
plaster, and putting the mixture in wood or plaster moulds, made to any desired size. When dry,
the blocks can be sold for hearthstone purposes. Old or dirty clay can be used up in the above
mixture. Old plaster is akso used in the manufacture of artificial manure. Enormous quantities of
old moulds, casts, and models are thrown away as useless when done with, or are simply used for
whitening floors and the like. In 1889 a patent was obtained by a Nottingham firm for the
" utilisation of old waste plaster moulds or casts." The waste plaster is broken up and reburnt in a
kiln (it must not be "dead burnt"); it is then drawn from the kiln, cooled, and pounded up or
ground ; it is then ready for u.se.

Pl.-\ster Casting. — The antiquity of moulding and casting in plaster is beyond doubt.
That the art of casting in plaster was not unknown to the ancients is clearly proved by such an
example as the figure of Eros, from Egypt, in the British Museum. Recent excavations by
Dr Flinders Petrie, at Tel-el-Amarna, brought to light many interesting architectural remains.
Tel-el- Amarna is situated on the Nile, Egypt. It was founded by Amenhotep IV. about 1400 B.C.

Casting in Plaster. 283

Besides the floor and ceiling plaster already mentioned, Dr Petrie also found a number of plaster
casts, the plaster being a coarse greyish gypsum. This plaster work consisted of a number of
objects in cast plaster for building decoration, and slabs with hollowed portions, probably to be
filled up with inlaying, also of slabs with inscriptions in low relief None of these objects showed
tooling or hand work. They were all cast, with the exception that in a plaster cast of the king's
face (probably cast from a mould taken after death), the outlines of the eyes were tooled to make
them distinct. The dates are well authenticated by historical records. The.se plaster relics reveal
to us the state of the craft at a period of 3,300 years ago, a date anterior to the Exodus,
500 years before the building of Solomon's Temple, and more than 900 years before the age of
Phidias.

Plaster casting out of wax moulds has been greatly improved during the last generation.
Formerly the moulds were oiled for every " fill-in," and if out of a front and back mould, the back
was swamped with oil to make the cast come out easily. This constant oiling was a direct waste
of time and oil. It also caused the casts to have a yellowish appearance, and they had to be placed
in the sunshine to make them white. The first and second casts were the most yellow, and when
extra white work was desired, and there was no sun, they were in some instances destroyed. The
moulds were also placed in front of a fire to render the wax more pliable for easing. This was also
a slow process, and as the moulds were not uniformly warmed, they were hard to ease, and
consequently the cause of much broken ornament. The introduction of warm water for rendering
the moulds pliable was a decided improvement. The following is the most modern and effective
way of producing good plaster casts : —

After oiling the mould and washing it out with soap water, the plaster is gauged as already
described. A small portion is poured over the mould, and then it is brushed all over the surface
and into the deep parts and angles, so that it will expel the air and fill ever\- part on the surface.
This brushing in of the liquid plaster must be done quickly and uniformly, using the brush to push
the plaster over the surface and expel the air, so as to avoid blubs and seams on the face of the
cast. The plaster must not be dabbed with the brush, because the brush takes up a portion from
the surface and admits the air, which causes blubs. Dabbing tends to make the surface of the
mould rough, and also work the surface oil into the plaster, thus making the cast more difficult to
take out. If the mould is small, the pla.ster may also be forced into the cavities by blowing it with
the mouth or with a bellows, and also by violently shaking the mould. If the plaster is properly
brushed in, it will suffice for all purposes. As soon as the surface is brushed in, the remainder of the
plaster is poured on and pressed in with a brush or a gauging trowel. The upper surface is then
ruled off flush with the mould rims, and then the fixing surface ke)-ed with a scratch drag. When
the plaster is set, or nearly so, the mould is placed in warm water for about five minutes, or until
the wax is sufficiently warm or flexible to admit of its being eased without cracking. It is then
taken out and eased or sprung to release the cast. This is done by holding the mould with the
hands and pressing the rim with the thumbs. This is continued until all the rim is eased and
sufficientlj' sprung to allow the cast to be easily drawn out. Thick or deep casts are more difficult
to draw out of the mould than thin or shallow casts. In this ca.se the mould should be turned face
downwards and \iolently shaken, or the rim gently beat on the edge of the bench. If the mould is
too large or heav\' to be turned up, lay it solid on a bench and gently prize the cast up with the aid
of a chi.sel. When casting small enrichments, place about six moulds close together, side to side,
and fill them all in one operation. If the wax is well tempered, and the atmosphere warm, the
moulds may be immersed in cold water. All cast work should be trimmed before the plaster is

284 Plastering — Plain ami Decorative.

dry. Tliin or tender casts are strengthened b\' inserting si>lints of wood or cane, reeds, rushes,
string, canvas, or galvanised wire in the plaster before it is set.

Hollow Casts. — When casting large work, the casts should be made hollow, the thickness of
the cast depending on the size of the casts and the purpose for which they are intended. The casts
may be strengthened bj- in.scrting rod iron or strong wire. The iron should be warmed and clipped
into or rubbed with wa.x to |)revent it from rusting and disfiguring the plaster. Hollow casts are
made by pouring in a portion of gauged plaster into the mould, and shaking and rolling it so that
the plaster maj- go into every part of the mould. Pour the surplus plaster into the basin, and keep
turning the mould over until the plaster in the basin shows signs of becoming firm, then pour it
into the mould and kcc|) turning the mould. Another gauge should now be poured in before the
first is .set, continuing this until the cast is sufficiently thick. When the mould is too heavy or
large to be conveniently rolled or shaken, suspend it with ropes from the ceiling, or lay it on a bed
of old bags or shavings to facilitate the shaking and rolling without injury to the mould.

Furred Moulds. — The surface of wax moulds .sometimes becomes coated with a white
substance known as " fur," which adheres to the cast and makes it difficult to leave the mould.
This fur is cau.scd b)' there being lime or sulphur in the plaster. When a mould becomes furred, it
should be washed out with clay water or with sugar water. Furring may be prevented by mixing
a little brown sugar with the oil used for the moulds.

Strong Pl.vster for Cast Work. — Plaster is often gauged with glue water to retard the
setting, so as to allow the necessary time for manipulation. Glue also tends to harden the work
when set. This mixture is useful when setting plain surfaces, but owing to its slow setting, it is
impracticable to use it for casting ]3urposes. This ma_\- be remedied b)- adding sul|3hatc cjf zinc to
the plaster and glue, which neutralises the slow setting and gives greater hardness to the work when
set. The proportions are from 3 to 5 lbs. of glue and li lbs. of .sulphate of zinc to each 100 lbs. of
plaster. The glue and sulphate of zinc are dissolved in water, and the plaster subsequently added
when gauging. This form of jjlaster maj- be advantageousl)- used for casting in jelly moulds, also
for fibrous plaster work.

Casting Wiiitk Ck.mkxts. — When casting Keen's or anj' other white cement, or superfine
plaster out of wax moulds, the casts are liable to be slightly stained, or have a \ellow appearance,
especially if the wax is old or soft. If ])ure white casts are desirable, the j-ellow tinge ma\- be
prevented bj- gi\ing the moulds a coat of thin and clean shellac, and then oiling them with salad
oil, or with fine white lard thinned with clear paraffin oil. The oil should be sparingly and evenly
brushed over the mould. A ball oil-pot is excellent for this purpo.se.

The sii[)erfine quality of Keen's or other white cement is generally used for cast work. The
cement should be gauged moderatelj' stiff, and a part of it brushed over the surface of the mould.
Another portion of cement is then laid and pressed all over with a sponge, to consolidate the stuff
and extract the surplus water. As the water accumulates in the sponge, it must be squeezed out.
When the surface is formed, the remainder of the cement is stiffened with Axy cement and then
pressed into the mould until it is full, then the surface is ruled off, keyed, and allowed to remain
until set, after which the mould is immersed in water for a few minutes, and then the cast is
extracted. Plaster, sulphur, and Spence's metal are sometimes used for making moulds for casting
white cements. They produce sharp and white casts.

Casting Portland Cemknt. — Portland cement casts for decorative work are produced by
two processes. The first and most generall)- known is the " wet process " ; the second is of recent
date, and is termed the " dry process." After a careful study of the nature of Portland cement and

Casting in Portland Cement. 285

aggregates, and their proper gauging, also the seasoning and oih'ng of the moulds, the casting of
clean and sharp work will be easier and more accurate. Portland cement castings are sometimes
strong, but disfigured with small surface cracks, generally termed "fire cracks." This term is wrong,
as they are really water cracks, and are caused by the materials being gauged too .soft or sloppy,
through using more water than is actually required for gauging, and also by the moulds not having
been properly seasoned, or not being watertight. The excess water, attracted by the unequal or
excessive suction of the mould, collects in small rivulets and percolates through the weak and porous
parts in the mould, leaving minute fissures or marks somewhat like a spider's broken web or a fine
line map. Hence the necessity of well-.seasoned and watertight moulds, and firm and uniform
gauging. Excessive suction is sometimes caused by the plaster case of piece moulds. This may be
prevented by plunging the case into water until fully charged with moisture, also by brushing the
backs of the plaster pieces with water. The outward application of water [)re\ents the porous nature
of plaster absorbing the water or liquid cement from the cast.

The best and cleanest casts of small enrichments are obtained by using neat cement. The
cement for the surface coat on the moulds should be sifted through a fine hair sieve or a muslin bag.
Fine ground cement .sets quicker and makes sharper casts than a coarse ground cement. Cast
work from gelatine moulds should also be compo.sed of neat cement. Rough or sharp aggregates cut
and destroy the mould's surface. Sand being plentiful, and obtainable in most districts, is the most
general in use. For cast work it should be sharp and well washed. Granite, slag, stone, or brick,
broken small and free from dust, make good aggregates for cement casts. They are used in the
proportion of i part of Portland cement to 2 of aggregate. The moulds, after being seasoned, are
first oiled and then brushed over with " slip " (neat cement), and then the gauged concrete is laid
and pressed into the angles with a stiff brush, and formed to the required thickness with a gauging
trowel. Large casts should be made hollow, to save materials and weight, and to afford a key or
fixing bond. The angles and insides of deep hollow casts are strengthened by bedding broken
bricks, tiles, slates, or bits of old concrete into the gauged stuff before it is set. Large casts are also
strengthened by forming partitions in the hollow interiors with any of the above lump aggregates.
Casts intended for constructive purposes should be made solid, the centres being made up with a
rough concrete of broken bricks, or other similar cheap material.

All cast work when taken out of the moulds should be stopped and cleaned up at once, and
air-dried for a da>-, then kept in water for not less than three days. This not only hardens the casts,
but exposes any weak spots or blemishes, and enables any defects of any kind to be made good before
they leave the shop. Casts after being taken out of the water should be exposed to the air from one
to three days, according to the state of the atmosphere, and, if discoloured, the surfaces should be
brushed or washed with a thin solution of neat, or coloured Portland cement. If the casts are
coloured, the wash is tinted with the same colours as used for gauging. The washing must be done
before the surface is dry, or it will rub off. Casts that are chipped or blubb)- on the surface should
be made good and stopped as soon as taken out of the mould.

When casting out of a gelatine mould, a fine gloss can be obtained on Portland cement casts by
brushing the face of the mould with a solution of common brown sugar dissolved in water. If the
gelatine is old, apply the solution slightly warm.

Water-Seasoned Plaster Moulds. — Sea.soning plaster moulds with water as a substitute
for oil or other similar materials is a method that I have introduced and successfully used for
obtaining a limited number of Portland cement casts. Temporary seasoning of plaster moulds
with water is cheaper and more expeditious than permanently seasoning with oil, and it may safely

286 PIasteri)ig — Plain and Decorative.

be cmploj-ed when time is brief and oiilj- a icw casts are required. Tlic mould, as soon as made,
is charijed witli water to correct the suction of the plaster and prevent adhesion of the cast to the
mould. The mould is placed in a \essel containing water, until it is nearly level w ilh the top
mould rim, taking care to prevent the water getting inside. When the mould is fully charged, take
it out and wipe off any surface moisture, and then brush it with paraffin oil or soap solution,
and fill it in at once. The process of water-seasoning is required for e\ery cast. If the materials
are properly gauged and laid in the mould, the cast w ill readily lea\e the moukl clean, and the cast
will be sound and free from water cracks.

Casting Cement Mcjui.dings (Wa.ste Mould Process). — Gothic mouldings, or models
of circular mouldings, having deep and narrow undercut .sections or parts, cannot alwajs be cast in
plaster piece mould ; and if gelatine is used, it is difficult to keep the long and narrow projecting
parts of the jelly mould in a true position. The cost of jelly or plaster piece moulding is in many
instances too great an item to jjrove remunerati\e, especially if a few casts only are required.
Running undercut mouldings in Portland cement or white cements for planting purposes is a slow
process. If the mouldings were run in long pieces and cut to the required lengths (as done for
ordinary jjlaster), the overhanging parts of the moulding would require considerable care and
nursing to form up and finish with Portland cement, thus causing the work to be tedious and
expensive. In order to avoid the.se difficulties and decrease the expense, I have introduced the
following method, called the "waste mould process," which is as follows: — Run work is not
so close in texture, is more liable to laminate or flake, and is not so strong as cast work. A mould,
or any fence which repels the expansion of the cement, helps to compress and strengthen the work.
The cement can also be used stiffer and more firml)- pressed and consolidated in a mould surrounded
on all sides, than if laid on an o\>c\\ bracket or core. The greater amount of working on the
materials by the trowel and running mould also tends to weaken the setting and hardening ])owers
of the cement. Portland cement mouldings having deep undercut parts are best produced by using
a run waste mould for each cast. This is effected by cutting a reverse running mould, and w ith it run
a casting mould. When practicable, a fixed core should be made, so as to form the upper or finishing
coat (which is the waste mould) as thin as possible, taking care that it will draw and leave the core
freely when taken off with the cast. The less plaster in the mould, the less chipping will be required
when freeing the cast from the plaster. Season the mould with water, as already described, anfi fill
it in, and when set the combined mould and cast is taken off the core and placed in water for one
or two days, which hardens the cast and softens the plaster. It is then taken out, and the cast
freed from the plaster with the aid of a mallet and chisel. The core will serve for a number of waste
moulds. This process of running waste moulds is useful, and will suggest itself for a \ariet}' of
purposes.

Pressed Cement Work. — Portland cement cast work produced by the dry process is termed
" pressed work." This is a method which I introduced thirty years ago, and extensively used
on the Redcliffe Estate, \\'est Brompton, London. It is clean and expeditious, and the work
has a close resemblance to the grain of natural stone. It is well adapted for casts that ha\e
large or flat surfaces, such as pier caps, coping, blocks, quoins, dentils, &c. The plaster piece
moulds are coated with shellac, and kept as dry as possible; they are never oiled, but simply dusted
with a fine muslin bag containing I'rench chalk. The gauge is usuall)- i part of Portland cement
and 2 parts of washed sharp sand, fine granite, slag, or stone, that will pass through a sieve having
a ^V-'"ch mesh. No more stuff should be gauged than will fill in one large mould, or one small
mould two or three times, or as much as can be used in one hour. It is better to gauge often, and

Casting Poytlaiid Cement — Dry Process. 287

in small quantities, than in lars^e quantities, especially if usinjj a small mould. If a large mould is
being used, as much materials as will fill it should be gauged at one time. The mixing and gauging
is best done on a bench or a raised board, and with the aid of a mi.xing rule. This is a piece of
wood rule or a planed board about 2 feet long, 4 inches wide, and ?, inch thick. The .sand is first
measured and spread on the gauge board, and then the dry cement is measured and sprinkled over
the sand. The mass is then gathered into a heap in the centre of the board by the aid of the
mixing rule, and cut and drawn in layers about i inch thick, until it is all at one side of the board.
The mass is again gathered, and cut and drawn again till thoroughly mixed. It is then spread on
the board in one layer from 2 to 3 inches thick, and a little water sprinkled over it. It is afterwards
gathered together, and cut and drawn in flakes backwards and forwards, as when mixing, two or
three times, adding a little water by sprinkling until the mass is moi.st like damp sand or snow.
The proper consistency is tested by taking a handful and squeezing it like a ball. If it does not
stick to the hand or crumble, but retains its form, it is fit for use ; if it sticks to the fingers, it is too
damp. It is better to use little water at first, and to add more if the gauge is too dry, than to use
too much at first and ha\e to add dry stuff to obtain the proper consistency. A good plan is for
one man to work the mass backwards and forwards with the mixing rule, while another sprinkles
the water on. The water is then sprinkled more regularly, and the proper consistency better
arrived at. When the gauging is finished, a portion is laid into the mould till there is a layer from
I to 3 inches thick, according to the depth of the mould or thickness of the cast. The first layer is
consolidated by beating with wooden punches and mallets. This process of adding fresh layers of
stuff and beating and ramming them is continued until the cast is flush with the rims of the mould.
To obtain sound work, special attention must be given to the following details. If the surface of
the mould is large and flat, the first la\-er is consolidated by beating with a flat wooden mallet.
If the mould has an ornamental surface or deep parts, the stuff is first rammed, and then beaten
with a wooden rammer or punch, a mallet being used to tap the head of the punch with a .series of
gentle but rapid blows, the punch being moved along the surface of the loose layer.

The punches for impacting are made of pine or other .soft wood, and vary in size according
to the size and form of the mould. The most useful sizes for ordinary work are from 8 inches to
12 inches long, and from A inch to 3 inches square. Care must be taken when ramming and beating
not to break the surface of the mould. This is best prevented by having the first la\-er thick, and
first pressing and ramming it into the angles and 'deep parts with a punch, and then using the
mallet on the punch. When ramming or beating deep or round parts, the punch should be smaller
than the parts. It should also be rounded off at the points for curved part.s.

When the first layer is thoroughl\- consolidated, its upper surface is roughened with a pointed
tool or drag to give the key for the next la>-er; another portion of the gauge is then laid on and
beaten as before ; and so on until the mould is full. The last layer is left full above the upper
edge of the mould, to allow the stuff to be well beaten, so that the upper edges of the cast will be
solid. When the last or upper layer is beaten, the surplus stuff is worked off with a straight-edge
until the cast is flush with the mould. The centre of the ca.st is then scooped out until the
sides and other surfaces are from 2 inches to 3 inches thick. This is done to save materials
and weight, and to give a key or fixing bond. The cast should be taken out as soon as
pressed, but as the stuff is not nearly set, the cast has to be supported until .set to allow of
its being taken out of the mould. This is done by filling up the hollow part with neat moist
sand of about the same dampness as the gauged stuff. The sand must be carefully pressed
into position, so as not to disturb the cast. The sand is laid and pressed until flush with

288 Plastering — Plain and Decorative.

the top of the mould. Tlie sand will prevent the cast from collapsing when the mould is being
turned over to take the pieces off the cast. After the sand is pressed and ruled flush with tlie
mould, a little fine sand is sprinkled on the Ujjper surface of the mould and cast. A strong
inflexible board or a slate is then laid on the top, and gently moved with a circular or backward
and forward motion, so as to spread the fine sand, and to give an equal and solid bed for the mould
and cast. The board is held firm to the mould, both are turned over together, and laid on the
bench ; the case and then the pieces of the mould are taken off; the scams arc now pressed in with
a small tool, or a small hardwood float. Great care is required not to disturb or shake the
mould when turning it over, or the cast will get cracked or otherwise spoilt. Care is also required
when taking off the plaster pieces .so as not to break the unset cast. The plaster pieces will leave
more freclj- if they are gently tapped witii a hamniL'r. If the mould is large and hea\y, it should be
laid on a board having a narrow cleat fi.xed at one edge to prevent the mould from slipping when
being turned over. The top board for heavy casts should be perfectly rigid, as the least yielding or
bending of the board will crack the un.set cast. Old cistern or billiard slates are the best kind for
large and heavy casts, whilst old tiles or roof slates will do for small work. Wood boards can also
be used for small work. The cast after the seams are pressed is allowed to stand from half an hour
to one hour, according to the state of the atmosphere. It is then gently sprinkled with water, care
being taken that the water does not descend with too much force on to the green surface of the
cast, or it will disturb and spoil it. After standing for another three or four hours, according to the
state of the atmosphere and the .setting of the cement, the cast is again watered, but this time more
frcel)-. The watering is repeated at intervals for a day or two, or until the cast is .set, and sufficientl)*
hard to be handled. It is then put in water, and left for not less than three days. A sponge or tool-
brush half filled with water is useful for the first damping of small casts. The brush or sponge is
held near the surface and gently squeezed, so that one drop of water will be transferred to one spot.
This will at once sink and spread ; another drop or two is transferred to another part, and so on till
the whole surface is slightl)' damped. If the atmosphere is hot and dry, or the cement quick
setting, the seams should be pressed in as soon as the cast is taken from the mould. If thc\- are
allowed to drj- or set, they cannot be properl)' pressed, and will leave a mark. The first damping
should also follow immediately after the seams are pressed, to prevent too rapid drying and
imperfect .setting. The common or garden watering-pot with a fine ro.se is the most ready and
serviceable tool for sprinkling water when gauging, also for watering the casts, when nearly set.

Clean and hard casts are obtained b>' placing them as soon as made in a chamber charged
with vapour or in a moist atmosphere. If hot steam is used, the setting and hardening is greatly
accelerated. Pressed work does not require so many moulds as the wet process. As the cast
should be taken out as soon as pressed, one mould is generally sufficient for a fair iiuantit}- cjf
casts. In fact, one mould, if kept dr)- and whole, is enough for one man to ])roduce anj- reasonablc
number of casts. Of course the number of casts that can be obtained from a mould depends upon
the form of the mould ; for instance, a greater number of casts can be taken from a plain mould,
such as a dentil mould, than can be taken from enriched modillion moulds. Again, the number of
casts obtainable de[)ends greatly upon the man who manipulates the mould. I have seen a mould
rendered useless in the production of thirty casts by unskilful working, and a mould still good
after eighty, and even ninety casts, had been taken from it. This method effects a saving in the
cost of making piece moulds, and as there is no time wasted or lost in waiting for the stuff to set, as
in the wet process, there is a considerable total saving. E. Suitall and m\- brother, R. Millar — both
now dead — and T. Thorne were the first exponents in this class of work, and the)-, after a few days'

Reducing and Enlarging Irregular Figures.

289

practice, turned out clean and sharp work. Large quantities were made with great ease in a
surprisingly short space of time, and as one of them said, it was like " shelling peas."

Where building stones are scarce and sand plentiful, or where .sand is to be had in abundance
at little or no cost, as it should be at most parts of our sea and river shores, building blocks, plain
or moulded, can be produced with great strength and durability, both quickly and cheaply, by the
use of hydraulic power. Mr T. Potter, in his book on " Concrete," in reference to this class of work
on the Redcliffe estate, executed under the author's supervision, after a period of nearly thirty
years' wear, says " the principal portion appears to be sound and perfect at the present time."

Method of Reducing or Enlarging Irregul.-vr Figures.— The subjoined illustration
(No. 96) elucidates a method for reducing or enlarging irregular figures by means of squares.
To obtain an enlarged copy, double the size, of any design (say a cornice and modillion as shown),
draw any number of squares as shown in Fig. i, then draw the same number of squares but double

Fig

2 3 4?

7 B <> 10 11 12

i.-:-

— ;.—,--'

...._...: — -..^ —

:-4-

! K

Frrr

TTTTTTrrrrr

„,.,-..---

—■:

■-r-f-r--

"-. .-— , — ; —

\"\

Ife

'; 1

No. 96. — Reducing or Enlarging Irregul.ar Figl'res.

the size on a sheet of paper and number the lines ; then transfer the various points to the proper
places, which will enable a fair copy, but of twice the size, to be easily drawn, as shown in Fig. 2.
By the same means any desired size may be obtained. This same method is also employed for
obtaining reduced sizes of the original copy. Modellers and shop-hands will find this method
useful when making full-size, double the size, drawings, &c.

CHAPTER X.

MODEL AND RUNNING MOULD .MAKING.

To Draw a Truss— To Make a Model of a Truss— Hinged Moulds— Diminished Models— To Make
A Kevstone— To Set Out and Make a Corinthian Column Capital— To Make a Pilaster
Capital— To Model a Corinthian Capital— To Mould and Cast a Corinthian Capital— To
Make Composite, Doric, and Tuscan Capitals— To Set Out and Make Ionic Capitals and
Entablature— To Draw the Ionic Volute— Centre Flowers— To Make a Centre Flower-
Prize Centre Flower — Cast Enrichment Mitres— Runninc, Moulds— To Make a Running
Mould— Running Moulds for Enriched Cornices— Twin Slippered Mould— Radius Mould-
Arch Radius Mould— Hanging Mould— Running Mould for Splayed Angles— Muffled
Moulds — Notes on Running Moulds.

To Draw a Truss and Cornice. — To become an expert model maker the worker should acquire
the power of drawing the model as well as making it. A knowledge of drawing is also essential
in setting out to scale and forming full-sized or working drawings from small designs. The
annexed illustration (No. 97) elucidates the method of drawing a truss and a cornice. This stj-le
of truss is generally used for the support of classical cornices placed over doors and windows.
The line of pilaster, with architrave, frieze, and cornice, is also given, with the proportions figured.
The architrave, frieze, and cornice (Fig. i) is in height half the breadth of the opening, and the
architrave one-sixth. The frieze and cornice being divided into seven parts, four go to the cornice
(as shown above the truss) and three to the frieze, which gi\es the size of the upper spiral of the
scroll. The longest part of the scroll (y g) takes four parts, and the lower spiral two parts. The
projection of each spiral is to its height as eight to seven. The thickness of the scroll is always
the .same as that of the pilaster it is fixed upon, that is, two-thirds of the architrave.

The spiral is formed in the same manner as the Ionic volute, with this difference, that the
Ionic \olute has twelve centres, this has but eight. The centre or eye of the spiral is drawn to a
larger scale (Fig. 2), with its divisions and centres marked. Begin the spiral with the first centre
from I to 2, then from 2 to 3, and so on. The centres of the segments are found as follows : — The
first is on the same line with the first centre of the upper spiral, continued to the line of pilaster at
D. The lower is six parts of the smaller spiral distant from the extremity of the lesser spiral, as
shown by the quadrant in the dotted lines .\ 13 C, and the lines C D, drawn from centre to centre.
Join both segments in their proper lengths. The moulding in front elevation (Fig. 3), or the
thickness of the scroll from E E, is divided into seven parts. One goes to each of the outer fillets,
and one to the middle bead II, with its lists. Each list is one-fifth. The centre of the bead is lower
than the outer fillets by one-seventh. Modillions for Corinthian cornices are set out and drawn by
the same method.

To Make a Model of a Truss. — For the sake of varict>- a different design of a truss
from the above is given to illustrate the method of making trusses, which are usuall)- divided into
three parts — viz., the " body " or main part, the " cap," and the " foot leaf" The latter in some

Drawing a Truss.

291

•^ y;-r^v/^.U,.y^. U:^<jr: <rJr. /r^u.JxJrJ^./r... Jr.Vr\,

districts is termed a " frog leaf." The parts, with the length of each, are shown in the annexed
illustration (No. 98), at Fig. 1 1. This gives a view of the truss to be made, c is the cap, 15 the
body, and F the foot leaf The whole truss is i foot 1 1 inches long. The projection of the body
at the greatest part is 5 A inches, as
shown on Fig. r. The projection of
a truss is generally taken at the lowest
member of the cap. In this case the
example is 4 inches in projection, as
shown on Fig. 10, which gives the plan
of the cap. When a truss is used as a
support to an arch, the lowest member
of the capping moulding of the truss
should not project beyond the spring-
ing of the arch, which is taken at the
soffit or the intrados, or at the sides or
extrados of the arch. This follows
the same principle of a well-propor-
tioned column and capital, where the
line of the enrichments just above the
astragal moulding is always in a line
with the shaft just below the astragal.
Trusses are sometimes modelled en-
tirely in clay and in one piece.
Another way is to cut the profile or
sides out of a plaster slab, fi.x them
on edge (the distance apart at the
insides being equal to the width of the
intended truss), and fill in the space
with plaster, then run the front profile,
and carve the enrichments on sides
and fronts. The general way in truss-
making is to cut two profiles out of a
plaster slab, and fix them on edge ;
then run the front profile, and model
the ornamental parts. There are
various ways of working this process,
but the following (one of my own) is
expeditious and accurate : —

First make a set of thickness
rules, equal in thickness to that of
the outside members of the truss,
and in lengths equal to the length and

widths of the truss, as shown b)- the five A's (Fig. i). Fix the centre one on a smooth
moulding board, then trace the profile of the truss on the board at each side of the rule,
then fi.x the top, bottom, and side rules to the extreme points of the profile as shown. Make

Fig. I.

No. 97.— To Dr.wv

Fig. 2. Kig.

.\ Truss and .\ Cornice.

292

Plastering — Plni)i niid Decorative.

up the inner parts of the profile with clay strips, as shown at is. These strips are held in
position with clay or plaster. This is indicated b>- the lighter-shaded parts of the drawing.
The clay strip need not be laid to a nicety, but leaving it back from the profile rather than
close to it, so as to allow about ,V inch of plaster to cut to a true line. The thickness rules
not only give the desired thickness of the sides or " cheeks " of the truss, but also (with the aid of
the clay strips) form fences to keep the liquid plaster in position. By the common way the profile
of the sides is traced on a plaster slab, after which the slab is cut into two pieces, and each part

Fi^ Q

r/$ 7

No. 98. — Makixc. the Model of a Trlss.

is again cut to the traced profile ; but owing to the narrow part at the bottom scroll being very
weak, these pieces are sometimes apt to get broken when cutting them to the profile. It will be
seen by noting this process that the wood and clay fences not only save the plaster, but also the
labour of cutting to the profile. This also allows a piece of iron or galvanised wire (w and W)
to be inserted at the narrow parts above the bottom scroll, commonly called " legs." These wires
strengthen the weak parts, giving more freedom when working the sides and front. Having oiled the
spaces marked c and c, they are filled in with plaster. Care must be taken to insert the wires, as

Making the Model of a Truss. 293

shown at w and w, then rule the surface off from the thickness rules. After this, clear a\va>- the
rules and clay fences, take up the sides, place them together on their ground or back edges, and
against a fixed rule, to prevent these from moving while being trimmed. When trimming the
outer edges to the exact profile, take care that they are true, smooth, and square. A file is an
excellent tool for forming this or other circular edges. After the outer edges of the sides are
trimmed, lay them flat on the moulding board, and mark the inner lines of the bands and the
spirals. This is effected by pricking or pouncing from the drawing. The outer edge of the band
forms the profile, and begins at the upper spiral, terminating at the lower one. These spirals are
commonly called " scrolls." The inner line of the band and .scrolls is indicated by the dotted line
as shown on Fig. 2. The sides are next sunk, as shown on Fig. 3. If the scrolls ri.se or swell
above the general line of band, these parts are worked up after the sides are sunk. The sides
are now placed on edge, as shown on Fig. 4. They are held in position by rules (as shown by the
four a's), which are secured by clay or plaster dots. The sides are prevented from moving inwards
by fixing wood or plaster stays from inside to inside, and from expanding by means of two or
more cramps, as shown at B and B. Fig. 5 is a section of the cramp. Having fixed the sides, a
foundation for the face moulding is formed by means of laths as shown at D, D, Fig. 4. The laths
must be fixed sufficiently deep to allow for a fair thickness for the face moulding. The depth is
determined by placing the running mould in position, and making a mark on each side ; then from
these marks form a line from end to end with the aid of a compass or a wood gauge. These
lines give a guide for cutting the necessary keying, and fixing the laths. After the inner sides are'
well keyed and damped or shellaced, the laths are fixed with plaster, gauged with lime putt\- water.
It ma)' be here remarked that when fixing newly made plaster pieces together, a thin coat of
shellac is an excellent substitute for water for stopping the suction. It is quicker, cleaner, and
stronger than water, and is not so liable to weaken the plaster. A plaster surface overcharged with
water is nearly as bad for fixing purposes as a dry surface.

After the lathing is finished, the face mouldings and the bed for the enriched parts are run.
Fig. 6 shows a section of the running mould for the upper and lower parts of the truss, as shown
at F, F, Fig. 8. The section of the running mould for forming the bed (c. Fig. 8) for the face leaf
is shown at Fig. 7. The stock is about i inch thick, and cut square (not splayed) at the parts that
bear on the edges and outer surfaces of the sides. The metal plate is cut short at the ends, leaving
just as much as will form the inner arrises. This prevents it from cutting the plaster bearings
when running. Care must be taken when running face moulds that they are done quickly, and
with few gauges, to pre\ent swelling and jumps in the mouldings. The running mould must be
muffled, and the moulding blocked out with gauged plaster and putt)- water. This should be done
in one gauge, or two at most. It is then finished with neat plaster. The mould is held at both
ends, and drawn toward the worker with a steady and equal bearing. .A smart workman can run
the face moulding without muffling the mould (by dragging the roughing out stuff down with a steel
drag to counteract the swelling of the plaster), while a boy is gauging the neat plaster for finishing
the moulding. The secret of success in this sort of work is to get the moulding well blocked out
and run fair with the first two gauges, and then follow ujj with the neat plaster before the other swells.
Work of this kind is generally blocked out with plaster gauged with lime putty water, and finished
with neat plaster. Plaster gauged with lime putt)- water does not take shellac so evenl)- as neat plaster.
The ends are made up, and the sunk panel (E, Fig. 8) is next worked b)- hand, which completes the
body of the truss, and it is ready for the enriched parts to be modelled. The modelling should
not be begun until the cap is made, and temporarily fixed in position, so that the general effect can

294

Plasto'iiig-

-Plaiii and Decorative.

be judged as a whole. The cap is made by first cutting a running mould to the proposed section,
allowing for a bed for the enrichment, as shown at Fig. 9, and then a sufficient length of moulding
is run and cut to the desired lengths and mitres, fixed together, as shown at Fig. 10, which shows
the plan of the cap. The bed is then filled in with clay, and the profile of the enrichment run
with a wood or jjlaster template, as shown at .\, Fig. S. The section of the run clay ready for
modelling, is shown at H. The cap enrichment and body enrichments F, !•', E, and c, also the side
enrichments and the foot leaf are then modelled. For large caps a length or the pattern is
modelled, moulded, and the requisite number of casts made and fixed, and the mitres formed.
For small work like the present example, the whole length of the enrichment and the mitres may
be modelled. If only a few casts of the truss are required, they are moulded direct from the
clay ; but if intended for .stock purposes, it is waste moulded, and then an original having a ground
is cast, and then cleaned up. If a truss diminishes in width, the face moulding is run with a
hinged running mould, made as follows : —

Hinged Runninc; Mould.s fok Di.minished Models. — The use of hinges on running moulds
is to allow the mould to gradually contract in width, .so as to form a diminishing moulding. A run-
ning mould hinged in the centre of the profile allows both halves to close up or contract uniformly
while being run u]i or down a diminishing space formed by two running rules or other bearings,
thus forming both sides of the moulding with an equal width and uniform profile at right angles
with the centre line of the moulding. Running moulds that are hinged at
the sides only cannot be run at right angles with the centre line of the
moulding, and when the mould assumes a raking position, it forms each
half of the moulding, with a different width arid profile, and as the diminish
increases, the rake of the running mould gradually becomes more acute.
Consequently the difference in the width and profile of each half of the mould-
ing becomes more and more pronounced towards the end.

The mould plate for a hinged running mould is cut to fit the section at
the widest part of the proposed moulding. After the profile has been roughly
formed, cut the plate through the centre, place the halves together in a vice,
and in one operation file both sides equal and true. This done, fix the half
plates on separate stocks, and connect them in the centre with a hinge, as shown on illustration
No. 98 (Fig. 12). This shows the form of the mould when at the narrowest part of the
moulding. The seam at the centre, caused b\- the junction of the two halves, is cleaned off by
hand. If the truss was enriched, as in the foregoing example, the seam would be covered by the
ornament. For small work, slippers are not necessarj-, but an allowance must be made for the
stock to overlap the sides of the truss, and form a rebate to act as slippers. The stock must not be
splayed at the bearings, but left square, so that they will run smooth and true, not cutting the
plaster bearings. This form of slipper is shown at Fig. 12. Hinged running moulds for large
work or special purposes are made with a slipper at each end, and in order to allow the mould to
contract freely, the slippers are connected to the stock by the aid of hinges. This and other forms
of hinged moulds are shown in the following illustrations.

To Make a Keystone. — A keystone is chcsen to further elucidate the method of running the
face moulding of a model that diminishes in width, as shown by illustration No. 99. The model
of a keystone is made in a similar way to that described for making the model of a truss, but with
the addition of using a hinged mould for the face moulding.

When cutting and horsing the plate of a running mould for the face of a diminished model,

No. 99.— Krvsto.ne.

Hinged Moulds for Diminished Models.

295

allowance must be made for the thickness of the sides of the truss, which in this case act as bear-
ing and running rules, the upper edges being the bearing and the sides the running rule. This is
exemplified in the annexed illustration (No. lOo). Fig. i is a view of the mould with the rebate at
each side of the moulding to allow of the bearing on the edges of the sides of the model and the
slippers bearing on the sides. Fig. 2 shows a plan and the position of the mould when in a
diminished form at the narrow part of the model. A, .\ are the edges of the model sides, C, C are the
hinges at the slippers and stock, and D is the hinge at the centre of the stock. It may be here
remarked that for a diminished moulding (say on the flat) the mould would be more easily run if
the slippers were between the running rules, as the>' would regulate and prevent the running mould
from expanding beyond its proper width, according to the dimini.sh, but in this case the edges of
the sides of the model are part of the face moulding of model. Hence the reason for having the
slippers on the outside, and bearing against the sides of the truss.

Where the moulding is wide, it is sometimes difficult to keep the slippers square when working
the running mould, thus causing the halves of the moulding to be unequal in profile. This maj' be
avoided by inserting an iron rod through the slipper, as shown at B on Figs, i and 2. This rod is
about \ inch in diameter, with a round head at one end and a screw nut at the other. When the
mould is in position at the widest part of the moulding the nut is screwed up tight to the slipper.

No. 100. — Hinged Moulds.

When running the moulding, take hold of the rod in the centre with the right hand, and bear on the
mould with the left hand. Then draw the running mould towards the diminished end. It will be
seen that this will keep the slippers parallel with each other, thus allowing the halves of the mould to
collapse regularly, and form the moulding equal in profile. The holes for the rod must be made
sufficiently large to allow the rod to work freely as the mould collapses. As already stated, a
hinged mould can be run more easily between running rules than if bearing on the outside. This
method is shown at Fig. 3, which is the plan of a hinged mould with the slippers bearing against
the running rules A, \, as used for running up a moulding on a wall or a cove. Equal-sided mould-
ings or column flutes which are diminished in projection or depth as well as in width are sometimes
run by the aid of a rule diminished on the upper edge to give the diminish in projection, and fixed
according to the required diinim'sh in width. In this case, a fillet, as shown at B, is screwed on to
each of the slippers, so as to form a rebate, and bear on the iimer and upper edges. This method
can only be used where the sides of the moulding butt against a stile, so as to cover the unequal
depth of the two outer members or for similar purposes.

To Make the Capital for a Corinthian Column.— The anne.xed illustration (No. loi)
shows the elevation of a Corinthian capital from Palladio. There is more work in making a
model of a capital (commonly called a " cap ") for a Corinthian column than any other enrichment
used in the plasterer's craft. After the main leaves and the volutes (one of each) are modelled, they

296

Plastcring-

-Plaiii ami Decorative.

arc waste moulded, and then each leaf is piece moulded, or the "tips" or ends of the leaves which
curl over arc cut off, so that they can be back and front moulded. By the former way, 16 mouklinL,'
pieces are required. It usually requires 88 separate pieces (including the tips) to make one com-
plete column, and the)- consist of the following: — 2 halves of the vase or bell with abacus, 8 leaves
and 8 tips for the first or bottom row, 8 leaves and 8 tips for second row, 4 angle volutes and 4
tips, 4 middle volutes, 8 volute leaves and 8 tips for angle part, and 8 tips for centre parts, 8 husks
or springers for volute leaves and 4 pateras, and 4 stems for same. The first part of the process is
to set out a full-size section and plan of the bell from the drawings. The "vase," technically
termed "bell," is that part between the astragal and abacus moulding, and which forms a ground
for the ornamentation. The "astragal," also known as the "necking" moulding, with about i inch
of the shaft, is run with the bell, to serve as a guide for modelling, and for judging of the general
effect of the cap as a whole while the modelling is in hand. The necking is generally cast with
the bell for work that is to be afterwards painted, but for scagliola or polished work the bell is
cast to the top of the necking, where the joint with the shaft cannot be so easily seen as it would be
if made below it. The plan and section of the abacus is also set out, using the same scale as used
for the bell. Some architects sup])ly full-size working drawings and details, while others only give

the diameter and height of the cap at the astragal, so it behoves
the plasterer and modeller to be prepared for the latter emer-
gency, also for his own benefit and ad\ anccmcnt to be well up
in all the details of heights and projections. The annexed
illustration (No. 102) elucidates the method of setting out and
making a Corinthian cap. As in practice when making a cap,
one-half of the plan is given, and as the same method is used
for a pilaster, the plan is divided to show a quarter of each, as
shown in Fig. i. The quarter plan of the column cap is shown
at A, and the pilaster at B. Each quarter shows the diameter
line, and the positions of the \olutes, leaves, and abacus, and
the plan of the shaft with the flutes just below the necking
moulding; the latter part -is omitted to show the other parts more
clearly. Pilasters are sometimes used insulated or in a square
form ; but more frequently setnvithin a wall, and on!)' showing a fourth or fifth of the thickness or
diameter. A model of the half pilaster is usually made, so that when moulded it can be used for
casting two halves to form a square, or a fourth or fifth part, as required. The smaller parts are
obtained by stopping off the ends of the mould at the desired sizes. To set out the cap, first
divide the given diameter of the shaft at the necking of the elevation, as shown on Fig. 2. The
angles are cut off till from 5 to 8 i)arts wide. The length of the radius is the length between the
angle points E, E ; and by describing two arcs (a part of each and the radius is expressed by dotted
lines which spring from the points E, e), the intersection gives the point from which the desired
curve is described. It will be understood that the abacus moulding is not run as the lines shown
on plan, but after the length of the radius is obtained a sufficient length of moulding is run, and
then cut, mitred, laid, and fixed on the full-size plan of one-half of abacus. F"ig. 2 .shows a quarter
elevation of the cap, volutes, leaves, and abacus, c is a section of the bell and abacus taken at the
centre. The juojection of the lip of the bell varies, but is usually about "jl parts from the fini.shed
line, not the ground line of the bell.

When setting out the face line of the bell, be sure to leave a sufficient depth to allow for a

No. loi.— Corinthian Camtal from
PA1.1.AD10.

Setting Out and Making a Corinthian Capital.

297

necessary thickness for the first and second row of leaves. The face line of the first row shouW
never project be\-ond the shaft line just below the astragal moulding. The thickness varies accord-
ing to the size of the leaf and the desired relief A leaf for a cap 18 inches diameter requires a
greater thickness than one for a cap 12 inches diameter, so as to allow it to be safely handled while
being moulded, cast, trimmed, and fi.xed. A | inch thickness for a leaf of a cap 12 inches diameter
may be taken as a standard for the necessary working strength and relief Of course the relief can
to some extent be raised or depressed by the treatment when modelling. The raised edges of the
lobes, as seen in Greek foliage, appear to have a higher relief than the rounded off edges to be seen
in Roman examples, even when the leaves or foliage in both arc alike in thickness. In order to give
greater ease and freedom when running the bell, the running mould is horsed upside down. The
radius-rod should be fixed in a line with the mould plate, so that the centre plate will be in a line
with the centre pin, thus obtaining a true centre. If the radius-rod is fixed at the side of the wood
backing, the exact radius is not so true, nor can the mould be used for marking the upright lines
when setting out the spaces for the enrichments on the bell. A wood block or centre (the height of

No. 102. — To Set Out Corinthian Colu.mn and 1'ilastf.r Capitals.

the mould up to the radius-rod) is fixed on a moulding board, cored out with old bricks or plaster,
and fixed with gauged plaster, leaving a space of about i inch between the core and the running
mould. The core should be made about i inch over the half or centre line, to give a bed for the
plaster. It should be made b)- fixing a wood template (to act as a muffle) on the running mould,
then covering the rough brick or plaster core with gauged plaster, and finishing with the muflFled
mould. Sections of the various parts used when constructing the bell are shown in the annexed
illustration (No. 103). A is the centre block fixed on the moulding board B ; C is the rough plaster
core ; D is the plaster bell ; E is the running mould ; R the radius-rod ; and F is the centre pin and
washer. The position of the bell while the enrichments are being fixed is shown at H. It will be
understood that the bell is fixed on the abacus before the enrichments are fixed, also that all the
enrichments— with the exception of those that cover the joints of the two halves— are fixed in the
shop before being finall\- fixed on the columns.

After the core is finished it is brushed over with clay water, to prevent the bell from adhering.
and then two or three nails are driven at the outer sides of the centre line, to prevent the bell from

298

Phisteriiig — Plaiii cvid Decorative.

No,

103.— Seciion of Bell and Run-
ning Mould for Corinthian
Column Capital.

moving while it is being run. It is a good way to describe the plan of the half column on the board

before the wood centre is fixed, and divide the half circle into eight parts, to be afterwards carried

up and marked on the bell, and used for giving the spaces for the leaves. The radiating lines from

the centre should be carried out bcj-ond the bearing part of the slijjpcr, to prevent all the lines being

obliterated with wet plaster during the ])rocess of running the bell.
Care must be taken that the centre pin is fi.xed exactly in the
centre, or all the labour of the lines will be useless. The centre for
the pin is got by placing two set scjuares, one at each side of the
half cap line, and proving the centre on the centre block with a
straight-edge bearing on the upright edges of the set squares,
then reversing them to the quarter lines and trying the straight-
edge as before. After the bell is run, place the running mould in
position with the mould plate in a line with the lines on the board,
and mark the upright lines, from the astragal down to the bottom,
with a blunt knife bearing against the side of the mould plate to
give a true line. After the eight lines are made, the bell is taken
off the core and sawn at the centre lines. The abacus moulding
is run in one length, and cut into lengths to form one full front and

two half side curves, and two short pieces for the angle mitres. The method of finding the radius

and plan of abacus, with outline of bell, is .shown on the illustration. When the abacus is cut

and mitred, the bell is fi.xed on it, and the cap is now ready for the modeller.
To M.-\KE .\ PIL.^STER C.MMTAL. — To make a pilaster capital

of the same order and size as the above, run the bell with the same

mould as used for the column caj). First alter the horsing of the

mould, so that it will run on the flat. Then run a sufficient length

of straight moulding, and cut it into the desired lengths for the

front and sides. These pieces are then placed upright on a board

on which the plan of the bell has been previously set out. They

are then fastened together with plaster, and the mitres made good,

after which the abacus is fixed, and then the cap is ready for the

modeller.

To Model a Corinthian Cai-ital.— The Corinthian capital

is enriched with olive, parsley, laurel, or acanthus leaves. The

Composite is generally enriched with acanthus leaves. The acanthus

is a plant which gives great scope for fine treatment. It is a

creeping, flexible plant, generally found in damp situations, but can

be reared in most gardens. There are two species, one of which

is prickl)- and jagged, something like a thistle. The other is

cultivated, and has a smooth leaf The popular name for the

plant is Bear's Breech. The annexed illustration (No. 104) shows

the natural form of the acanthus leaf. There are a variety of ways

of treating it— the Grecian, Roman, and naturalistic, besides a great number of transitional forms.

The height and projection of the leaves is best formed by cutting the profile and size of the two

rows of leaves on a wood template, made to bear on the astragal and on the bell just above the

leaves. When the clay is built out. draw the template over until the clay has the proper profile.

104.— Natural Form of
Acanthus Leaf.

Setting Out and Making a Composite Capital.

299

Two or three nails driven into the bell, and two into the abacus, give a good hold for the clay at
the leaves and volutes. The various parts are now modelled. Only one angle and centre volute is
modelled.

To Mould and Cast a Corinthian Capital.— When the column cap is modelled,
the various parts are waste moulded, casts got out, cleaned up, and then permanently moulded.
The leaves are generally front and back moulded in wax. If the tips are not cut off, the whole
leaf requires to be piece moulded in wax. The usual method is to waste mould the clay model,
then get out a cast and clean it up, and then cut the tip off with a fine keyhole or band saw, or
with a twisted brass wire. They may also be cut in the clay if it is firm. They should be cut
slightl}' circular (across the leaf), to give a better bed when being fixed. The joints on the leaf and
tip should have a sinking about ^ inch deep, and leaving a
^-inch margin round the outside of the joint. When the
leaves and tips are moulded, cast, and the trimming and
scratching is being done, draw the point of the knife along
the sides of the sinking, and it will give an undercut, and
make a good key for the fixing plaster. The tips curl and
droop over, and it is important that the joint should be
strong to stand the pressure of the brush when being painted
or polished.

The volutes are piece moulded in wax or plaster, or a
combination of both. Usually the fronts are wax and the

backs plaster, or the fronts

can be piece moulded in

wax and the backs left open.

The volute leaves are piece

moulded in wax, as with the

volutes. It is advisable to

make a sinking when prac-
ticable on the back of all

enrichments before being

moulded. It saves plaster

and time in forming a deep

undercut. The backs of vol-
ute leaves and large angle

leaves on pilasters are some-
times moulded with gelatine to save piece moulding. The leaves and other dressings are
generally moulded in wax, because they can be kept as stock moulds for future use. The bell and
abacus are generally fixed together, and plaster piece moulded. The lines on the bell should be left
in the mould to give a guide for fixing the leaves, stems, ends of volutes, and ends of volute leaves.
The fixing parts of the leaves and other dressing should be sunk (as with joints and backs of the
leaves), to save time and scratching. It also gives a better key. A few small cross scratches with
the knife in the centre of the sinking, and round the other parts of the bedding margin, will help to
keep the leaf in position until the body of stuff in the sinking has set.

To Make a Composite Capital.— A beautiful example of a Composite capital is shown in
illustration No. 105. In some of the Roman Composite capitals, animals, the human figure, and

No. 105. — Composite C.\pital from
THE Arch of Titus.

No. io5. — Plan anu Elf.vation of the
Composite Capital.

300

PlastcyiHg — Plain and Decorative.

foliage are introduced. The Composite capital is made in a similar way to the Corinthian capital.
Illustration No. io6 shows the plan and elevation of the Composite capital, with the leaves out-
lined, and the centre from which the abacus is struck, as indicated b)' the intersection of the dotted
lines. The plan shows the projection of the leaves and the abacus. A scale is given to assist the
setting out. Only one volute is modelled. It is then waste moulded, cast, cleaned up ; then piece
moulded in plaster or wax, and the desired number of casts made. The face leaf on the volute is
sometimes cast separate. Since the introduction of gelatine, the volute with the face leaf is
moulded and cast in one piece. The small leaf that turns up from the volute towards the
abacus is cast separate. The other enrichments are cast as described for Corinthian cap leaves.

Doric and Tuscan capitals are so simple in construction that if one can make full-sized work-
ing drawings of the capitals to scale, and has mastered the construction of Corinthian and Composite
capitals, there should be no difficult}- in making models of the Doric and Tuscan capitals.

^ii^^K^^.

No. 107. — Plans, Elevations, and Sections of Ionic Capit.xls and Entablature.

To Set Out Ionic C.\I'IT.\ls .\nd Ent.vbl.vture. — There are several forms or designs
of Ionic capitals. In some the abacus is square and plain, others are curved on all sides,
and in others two faces are curved ; while the flanks or baluster sides, as they are sometimes
termed, are different in conformation, both vertically and horizontally. This capital is also made
without a necking, according to the style. In some a swag depends from the eye of the volute.
Whatever form the Ionic or voluted capital ma}- have, the method of making it is similar to that
described for the Corinthian capital. When modelling the egg and dart enrichment, care should be
taken that they .should be in proportion and be in a line or "principle" with the fillets and flutes of
the column.

Illustration No. 107 shows the elevations, plans, and sections of Ionic capitals, columns, and
entablature, with figured dimensions. Scales are given from which the various parts may be set
oUt to any desired size. These examples will be found useful, and a read}' reference when setting

Setting Out and Making Ionic Capitals.

301

out 01- making Ionic models for solid jjlastcr, fibrous plaster, terra-cotta, or cement work. A is the
elevation of an Ionic column, with base and capital. The abacus of this capital is square on plan.
The plan of this capital is shown at D, the profile at c, and the side or end at li. The elevation
of an Ionic capital, with an angular abacus, is shown at K, and the plan at F. The intersection of
the diagonal lines, which spring from the angles of the abacus, gives its centre and radius. The
elevation and profile of the Ionic entablature is shown at G. The frieze of this e-xampie is swelled
or cushioned. The plan of the soffit is .shown at II. The scale of parts, from which all the jjrojec-
tions and heights of the order are taken, is also shown.

As .some little difficulty may be experienced in setting out the volute, the following simple
method is here given : —

To Dr.\w the Ionic Volute.— The method of .setting out and drawing the Ionic volute is
elucidated by illustration No. 108. First set out
the profile of the capital, and through the middle
of the astragal A B draw the horizontal line E F ;
then from the top of the abacus draw the perpen-
dicular line passing through the centre or eye of
the volute, as G H. Within this circle are twelve
centres, from i to 12, on which the contour of
the volute is described. An enlarged sketch of
the eye is given in the upper corner of the illus-
tration. The method of setting out the twelve
centres is as follows : — Divide a geometrical square,
whose diagonals are one in the horizontal line,
and the other on the perpendicular line, crossing
each other in the centre of the eye. From the
middle of the sides of this square draw two lines
which divide the square into four, and each line
being divided into six parts, gives the twelve
centres as they are numbered in the eye of the volute.
To describe the volute, open the compasses from
No. I (in the eye of the volute) to the intersection
of the perpendicular and the lower part of the
abacus, and draw a quarter of a circle ; continue it
until it meets the horizontal line E F. Then on
the point 2 place the compasses, and open them to

the arch last described, and continue the arch till it meets the perpendicular line G II. Then place
the compasses on the point 3, and open them to the arch last described, and continue the arch line
until it meets the horizontal line E F. Then on the point 4 place the compasses, and open them
to the arch last described, and continue the arch line to the perpendicular G H. Continue this
process until the twelve centres or points are completed, and the contour of the volute will be
described as required. The inside line or band is described by a second draft in the same
manner as the former, only placing the fi.xed point of the compasses in twelve other centres,
very near the first, viz., one-fifth part of the distance between the former, reckoning towards the
centre of the eye. The twelve points in the e>-e of the volute are made larger than the others, on
which the inside line may be described as required.

No. 108. — To Set Out the Ionic Voli'te.

302 Plastering — Plain and Decorative.

Centre Flowers. — The use of centre flowers, sometimes called roses (Frencli, Rosace), for
ceiling decorations has jjone out of fashion during the last decade. This is partlj- due to the
recent revival of the Queen Anne style, partly to the caprice of fashion, and partly to a more
general use of panelled ceilings. Vet it is necessary that the plasterer should know how to
prepare the groundwork {ox the modeller. Formerly " plate flowers" were greatlj- in use. The
term " plate " was applied to these flowers because the foliage was modelled and cast on a level
plaster ground. Small centre flowers were generalK- cast on one plate, but large flowers required
se\eral ])ieces to complete the design. The enriched plates were let into the ceiling and made
flush witii the lime plaster, so that the plate formed a part of the ceiling. This method was
adopted to support the delicate foliage which was too weak to be cast separately. It was difficult
to make the joints of the plate smooth and level with the lime plaster, owing in many cases to the
uneven surface of the plate, caused by the plaster twisting after being cast. Owing to the difference
in the nature of the materials of the laid work and the cast work, no matter how smooth and e\en
the joints looked w hen new ly done, they had a more or less patchy appearance when oil painted.
Centre flowers having bold and deep relief were at one time largely used. These generall}- took
the form of a circular row of large leaves and husks, placed alternatcl}', which sprang from a
centre "seed," also called a "rose" or a "drop." This generally consisted of a row of small
inverted leaves surrounding a body of beads or balls, and an aperture in the centre for gas or
other pipes. Centre flowers of this kind were often finished with a border or wreath of laurel,
oak, or other lea\'es and husks. The various parts were cast separately, and fixed on the ceiling
after it was set. After the centre lines for the main leaves and husk (which generally consisted of
four, si.\, or eight of each) and the border were set out on the ceiling, the casts were held up
temporarily in position, and a pencil drawn round their bedding parts to give a guide for cutting the
lime plaster down to the laths, so as to give a key for the cast work. Another st)-le of centre
flowers consisted of foliage intermingled with swags of flowers, fruit, husks, &c., and some assumed
such elaborate forms that from fifty to si.xty casts were often required to complete a 6-feet centre
flower. W. Gillies, of Edinburgh, modelled a centre flower which consisted of eighty-five parts or
casts. T. Ryan, of London, designed and modelled a centre flower which required 127 pieces to
complete it. J. Steel, when working in Dundee, modelled a centre flower 10 feet 6 inches in
diameter, which required no less than 365 parts to complete the design. When comparing these
centres of many pieces with the present-day work, it should be borne in mind that a large number
of the pieces consisted of small plantings to obtain a relief in the foliage without resorting to
undercutting or piece mouldings. Most of the work was cast in front and back wa.K mould, and
the seams of the perforations trimmed off with trimming knives. These and the plate flower
undercut by hand were generally gracefuUj' designed and artistically modelled. The introduction
of fibrous plaster and gelatine for the production of undercut and tender cast work, and their
ready manipulation atid adaptabilit)-, has decreased not only the weight, but also the labour and
price of centre flowers. The decrease in price applies principally to stock patterns. The designing
and modelling of new patterns constitutes a separate item. The reduction in cost brought them
into more general use, and combined with the monotonous employment of stock designs, made
their use so common that the\- soon came to be considered vulgar by one class and superfluous
b\- others. But the extinguishing blow was dealt by the jerry-builder. This gentleman was aided
by the piece-worker and the Italian plaster caster, who by their ready-made centres, generally
cast in one piece, combined with their poor designing and their coarse workmanship, soon caused
them to be an unsought-for decoration. This applies more to a certain class of dwellings in the

Centre Flowers.

30J

suburbs of London and a few large towns. When the centre flowers are well designed, and the
work is done direct by a qualified master plasterer, without filtering through the channel of a
general contractor, centre flowers are still in demand, although in lesser quantities. Centre flowers,
square and octagonal on plan, are exten.sively used in America, but they are more appropriate for
square or octagonal panels than for plain or flat ceilings. Oval centre flowers are very fashionable
in France ; they are certainlj- more suitable than round ones for long rooms, just as a round one

No. 109.— Centre Flou eu, Pai.\ce Ci.uh, Lo.sdox.

looks better than an oval in a square room. l-"ormerly centre flowers were cxtensivelj- made in
carton-pierre, also in papier-mache, but these materials are now to a great extent superseded b\-
fibrous plaster. Cast-iron centre flowers have also been used, but owing to their great weight,
general flatness, and want of relief, their use is very limited.

To Make a Centre Flower. — There is a growing desire for the revival of artistic centre

304 Plasteying — Plain and Decorative.

flowers which points towards their more general use, not only as a centre decoration, but also
as a sanitary means for ventilation. The method of making and modelling them is here given.
Centre flowers are generally made with a sectional profile, which diminishes to the line of ceiling.
The modelling is done on this profile or ground. To allow them to be moulded, cast, and fixed
more easily, they are made in two or more parts. When setting out the ground, a bed or fixing
ground should be provided for the fixing of the smaller parts on the main part. .As an example
of the process for making a centre flower, the design in the annexed illustration (No. 109) may be
taken. This is from a photograjjh of a centre flower modelled by the author for the Palace
Club, Westminster, London, in 1875. This centre flower was originally made for circle panels, also
for square panels in the same ceiling. The square was made up with s[)an(lrils consisting of
medallions and sprays of laurel and oak leaves. The outer moulding and enriched border is a
later addition made by John Cordingley, for general use. The diameter is about 4 feet 6 inches.
Two of the four cupids and swags only are shown, so as to show the ventilating part of the centre.

The method of making this centre flower is as follows: — Illustration Xo. no is a half
section of the centre flower. This also shows the various parts, which are technically termed in the
trade thus : .\, the " body " ; c, the " centre " ; D, the " drop," or " pendant " ; R, the rim moulding
(this is generally taken as a part of the body) ; and B is the border. In order to give more facility

for moulding and casting large or deep
, Q , flowers, they are divided into four parts,

-Ti |t T ^ =« viz., the body (A including r), the centre

■ ■ (C), the drop (d), and the border (li). This

latter, if not too thin or weak, is generally
moulded and cast with the body. Before
cutting the running mould, a ground for
the centre must be made, as shown at G,
which is the bed for the centre. The
No. iio.— H.\i.F Section of Centre Flower. dotted line on the inside of the section

shows the perforation, and the dotted
lines on the outside show the profile of the clasp. It will be seen by the design that the pattern is
repeated four times, therefore a quarter of the body must be rvni for modelling purposes. Where the
pattern is repeated six or eight times to complete the circle, a sixth or an eighth part, as the case may
bc.'is'required. For some designs, especially where there is a straight leaf that runs in a line with the
quarter lines, and which can be modelled for covering the joints, the run ground can be cut to the exact
quarter. But in most designs it is advisable to run considerably more than the quarter of the ground to
allow of judging the effects of the right and left part of the pattern. If a permanent joint was made
at the straight or quarter lines of the circle, it would cut through the modelled work, and make an
unsightly joint. And as it would be scarcely practicable to cut the ground to a joint that would fit
the curves of the ornament, it is necessary to make a permanent joint, especially where there is not
much foliage, and which requires but little making good. A permanent joint may be of any form,
and is the joint at the ends of a cast which fit each other. The joint is made after the modelling
is done, and the process is shown in the next sketch. A length of the border should be modelled
before the joints are made. This border is modelled and cast separately.

Illustration No. Ill is a plan of the run body showing the quarter lines A B and A B.
The spaces outside the.se lines are the extra parts for modelling and jointing purpo.ses. G is the
bed for the centre. The quarter lines are to indicate the exact centre, and act as a guide when

Making a Model of a Centre Flower.

305

modelling C D is a centre line which is simply a guide for modelling purposes. These are made
before the modelling is begun, by laying the running mould upon the run body, and at the quarter
marks which have previous!)- been made on the running board, as shown bj- the line outside and
inside the bod}-. The marks are indented by drawing the point of a knife across the work and
against the mould. The ground is then shellaced and the modelling roughed out, as shown on
the sketch. The ornament in a line with the quarter line need only be modelled on one end, as
shown at the left hand side of the figure. Set out a quarter of the border as shown at H, and
model a length of the border. When all the modelling is finished, remove the border, and then cut
the body through the quarter lines from A to B with a saw. It will be seen that this cuts through
the foliage, which would make a bad joint, difficult to make good. It is therefore necessary to-

No. III.— I'L.\N OK Run Body ami Ki.\i Mouldixc. of Centre Flower, with Orna-ment Roughed out

IN iHE Clay Ready, for Tolntini;.

make a permanent joint at another part, where there is little or no foliage to cut, and where the
ground will butt against the band or continued part of enrichment, where the joint will be most
easil}' made good, and be least perceptible when fixed. This permanent joint is shown bj" the
dotted line from F to E. This is cut with a wire or a kc\h«lc saw, so that it will follow the curves.
Care must be taken not to disturb the modelling. The wire should not be worked too close to the
bands or foliage, but kept about -,V '"ch away, so as to leave a small portion of the ground (next to
the band) for moulding and trimming purposes. When the joints are cut, the two parts are then
temporarily fixed on a moulding board, keeping the straight joints together and the curved ends
outwards, thus forming a true and permanent joint, as shown on the subjoined sketch (No. 1 1 2).
The modelled work at the straight joint is then made good, after which the body is ready for
moulding. The border in this example is moulded separately.

To obtain the finished effect of the centre flower as a whole, it is necessary to run the centre
and drop parts before commencing the general modelling. During the progress of the modelling
they are temporaril>- fixed in position on the body to allow of modelling an>- clasp or other
connecting parts, and to judge the effect of the whole flower.

Illustration No. 113 shows a plan of the centre and the drop with a length of each enrich-
ment roughed out in cla\-. When cutting the running mould for centre, a temporar\- bed about

5o6

Plaster'uig — Plain and Decorative .

No. 112.— Permanent Toint ok the Body or the Centre Flower.

J inch thick mii.st be allowed for the perforated part, also a bed for the two enrichments on the

moulding, as shown on the section. The whole circle is run, and then a length of each of the

enrichments modelled. The profile for each should be formed with a template. The cupids, small

swags, and clasp are then modelled. They are then waste wax moulded, cleaned up, moulded

again, and as many casts got out
as will complete the circle. With
the exception of the cupids and
swags, the whole centre is then
moulded in one piece. A plaster
piece mould is made for the
cupids, and a wax mould for the
swags. The complete centre
may be moulded in one piece by
using gelatine. The drop is also
run separately, and then the en-
richment is modelled or carved.
It is then piece moulded in wax,
or moulded in one piece with
gelatine, as desired. The body is
waste moulded in wax, and an

original made. If it is intended to cast the body in one piece, the waste mould can be utilised

for casting the four quarters to complete the circle. They are then jointed and fixed on

a moulding board, and moulded in one piece. For solid plaster the border is generally

cast in short lengths, and fixed after the body is

fixed ; but for fibrous work, or when the border ;

is sufficiently strong, the border may be cast with

the body.

Prize Centre Flower.— Illustration No.

114 shows the plan and section of a centre flower

first prize for a design of a centre flower, given by

the Illustrated Carpenter and Builder in 1880.

The diameter is about 8 feet 6 inches, and contains

four medallions, representing the four seasons, the

centre being perforated to admit of ventilation.

A scale is also given. One-half of the section

shows the various parts and bedding parts of the

centre, a is the body, C the centre, D the drop,

and B is the border. The latter includes the small

point panels (\v and M) from which the swag of

husks depend. P is a section of the pendants on

the drop. This centre flower is .set out and made as described for the previous one, but with

the following exceptions. In this example, the permanent joint may be made in a line with the

quarter lines, which would be made through the medallions. The medallions, which are modelled,

moulded, and cast on separate grounds, would cover the greater part of the joint. The point

No.

13.— Centre and Drop with Ornament

ROUOHED OUT IN THE ClAV.

Designing and Making Centre Flowers.

307

panels (w, M) are cast separately, and the joints covered with the clasp patera, as shown at F on the
section. The small portion of the permanent joint at the band adjoining the centre is covered with
the clasp G, as shown on the section. The whole makes a clean and effective joint, which requires
little or no stopping. The centres and drop in this ca.se may be made in one piece, but it is

No. 114.— I'RizE Centre Flower, Plan and Section.

advisable to cast the pendants separately, and fix them afterwards. The swag border of husks
should be moulded and cast separatel)-. The cast would be sufficiently strong (from point to point
•of the swag) if cast in tow and plaster. They may also be cast in paste composition, with a
string through the centre to keep them together until the\- are fixed. Paste composition enrich-

308

Plastcritw — Plain and Decorative.

ments can be firmly fixed on lime plaster ceilings when dry with soft compo, glue, or a soft solu-
tion of glue and plaster. Fine brads or needle points driven through the thick parts of the
enrichments will further secure and also hold them in position until the fixing stuff is set.

Cast Enkiciimknt Mitres. — It has already been stated that .nitres for cornice enrichments
are generall>- modelled in situ. This is a good method for most kinds of enrichments, especially
for large work, or if the mitres are few in number. But if the enrichments are small or have

^ "T""
y^*^

-vi-i'--^^-

No. 115.— SOl-lTT Enrich.me.nt.

repeated short patterns, such as a guilloche, or if there are numerous mitres in the work, it is more
advantageous, both as regards appearance and time, to make a model of the mitre, then mould,
cast, and plant it. A simple way to make a model for casting purposes is to first set out the width
of the enrichment and the angle of the mitre on a moulding board, or on a plaster ground ; then
cut a straight cast in halves, and to the angle, taking care to preserve the main curves and lines on
each half. When cut, la\' the halves on the ground, and regulate the width apart at the angle, so-

■^^^^'^^Oi

No. 116. — Internal MirHE ok Soffit Enrichment.

as to obtain the best position to allow for a flowing curve, and one nearest to the general features
of the original cast. Now fi.x them on the plaster ground, and fill in the joint with plaster to make
up the ground of the model, and next model the parts required to join the ornament. The model
is now moulded, and as many casts obtained as may be required. The accompanying illustrations
will elucidate the method of making a model of a mitre, as also show mitres of various enrichments.
Illustration No. 115 shnws the straight cast of a soffit 9 inches wide, from which an internal right-

Casi Enrichment Mitres.

309

angle mitre is to be made. This soffit was modelled by the author for Messrs T. Cordingley & Son.
Illustration No. 116 shows the mitre of the same soffit. The dotted surface indicates the made-up
ground of the soffit at the joint of the two halves. It will be seen that there is only a small portion
of the foliage to model in this example, as indicated by the lighter coloured parts. This method of
cutting the straight cast and then modelling the foliage can be employed for making mitres in situ
on the building. Illustration No. 117 depicts various forms of enrichment mitres. Fig. i .shows a
right-angle internal mitre of a guilloche. The model of this mitre is easily made, as the band is
mostly straight. Fig. 2 shows a right-angle internal mitre of a guilloche, and Fig. 3 a splayed or
acute-angle mitre for a bay window of the .same enrichment. The bands of this guilloche being
small and wholly circular, it would be costly to work in situ, especially if there was a large number,
hence the reason for casting the mitres. Fig. 4 shows a right-angle internal mitre of a fret
enrichment. This being composed of straight bands, it is best to work them in situ, unless there is
a large number of mitres. For large and intricate designs, the entire model of the mitres should be

No. 117.— Cast Enrichment Mitrks oi- Guili.ciciiks am> Kkf.t.

modelled, instead of cutting a cast as described. Mitre lines for crown mould and bed moulds, such
as eggs, &c., are modelled on a cast of the enrichment, and then moulded and cast in the usual way.
Running Moulds. — A running mould is u.sed for forming the contour of mouldings by
running it over plastic materials while soft. There are five parts in an ordinary running mould,
viz., the plate, stock, slipper, wedge, and handle. The general construction or mounting the plate,
so as to enable it to be run straight and .square, is termed " horsing " or " horsing the mould."
There are additional parts used in some running moulds, such as " splash boards " and " metal
shoes." These and other parts are illustrated later on. Running moulds are sometimes made on
the building ; the plasterer cutting the plate, and a joiner horsing the mould. The general practice
is to cut and horse the mould in the plasterer's shop. In Messrs \V. Cubitt & Co.'s shop all the
running mould for shop and building work was cut and horsed by a plasterer. Running moulds
were formerly cut out of beech, boxwood, pear-tree, and other hard woods, also out of copper or
brass, the metal plates being fixed on a wood backing. They are now cut out of sheet zinc for
lime, plaster, and white cement wi)rk, sheet iron being generally used for Portland cement work.

3IO

Plastering — Plain and Decorative.

Copper is still used for a few purposes. Galvanised sheet iron is now also used for interior and
exterior work. Zinc is the best metal for most purposes. It is easily cut, and not liable to rust.
Sheet zinc for running moulds maj- vary in thickness from a thirty-second to a si.xtccnth part of
an inch, according to the size and requirements of the mould. The metal profile, termed the
"plate," is fixed on a wood backing, termed the " stock." This is then fixed to a wood bearing called
the " slipper," and supported by stays, which also form a handle. In former times the mould was
run without a " slipper," a rebate being formed at the bottom of the stock to bear on and against
the running rule. The mould having only this narrow and unsteady bearing may account for the
undulating lines seen in some of the mouldings in very old houses.

To Makk -V Running Mould. — In most parts of England running moulds arc " horsed "
to run with the right hand from right to left, while in Scotland, the North of England, and some
parts of Ireland, they are horsed to run with the left hand from left to right. The latter being the
most natural, is adopted here. There are various waj-s emplo}-ed to " horse " a running mould.
The following is the most simple, speedy, safe, and scientific. Illustration Xo. ii8 shows the
method of making. Fig. i shows a given section of an interior cornice with the ceiling and wall
line. To construct a mould to run this section, first cut the plate (.\). This is done by transferring
the outer profile of the mouldings on to the zinc sheet from which the plate is to be cut by aid of
tracing paper, or by pricking the profile on to a piece of common white wall paper. This paper

No. Ii8. — To Makk a Rux.ning Moi'i d.

or the tracing is then pasted on the metal sheet. The profile may also be pricked direct on to the
sheet. Having marked the profile on the zinc sheet, and allowed about i^> inches on the ceiling
and wall lines, also a sufficient width for strength, and fixing on a wood backing called the " stock,"
it is ready for cutting and filing. Care must be taken that the ceiling and wall lines are square
with each other. The profile is then cut with a pair of snips or scissors and small beads with
gouges, and afterwards filed true. After the plate is cut, place it in a vice, keeping the traced
profile clear, and towards the worker, so that it can be seen while filing. This allows the plate to
be easily filed to the exact profile. Zinc being of a soft nature, can be cut close to the profile ;
therefore little filing is required. Fine files are better than coarse ones for this work. A flat file
with a safe edge is an excellent tool for forming internal angles. After the profile is cut and filed,
a few holes are punched in the plate to admit of tacks or screws for fixing it on the stock, as shown
on the plate (a >

Mould plates for Portland cement and similar work are generally cut out of sheet iron. After
the profile is marked, the sheet is laid on a wooden block, and cut or punched with small chises,
and then filed to the true profile. After the [jlate is cut, the next operation is the horsing or

Constructing Running Moulds. 3"

forming the various wood parts, and fixing them and the plate together. The wood should be
planed on all faces before being cut. The first is the stock fB). This is cut out of pine wood from
i inch to I inch, according to the size of the mould. The top part, which bears on the ceiling, is
called the " nib," and the bottom part, which bears on the wall, is called the " toe." The plate is
laid on the wood as a guide for scribing the profile. The .stock is cut a little wider than the plate
to give more strength. The nib and toe are cut flush and square with the ceiling and wall lines,
but the profile is cut about /,,- inch less than the true or plate profile, and from this line the edge
is splayed to an angle of about 30'. This setting back of the wood stock from the plate profile,
and splaying the edge, allows any coar.se particles that may be in the materials used for the
mouldings, and which generally accumulate at the plate profile, to sink down, and free the running
edge of the plate. The splayed edge of the stock also allows the material to partly feed the
mould. When running mouldings with coarse materials, .such as cement and .sand, the stock should
be set back i inch, so as to allow for a space for the coarse particles. The bottom end of the stock
is cut square with the toe, allowing a depth of about I inch to fit into the slipper. Where steam
power is available, a band saw is a speedy tool for cutting the jjrofiles of stocks. The slipper (C)
should be squared on both sides and edges, and then a groove about i inch deep cut across the
centre of the upper side to receive the stock. The side of the groove ne.xt to the plate is cut
square from the running edge of the slippers, and the other side is cut slantwise, so as to admit of
a wedge. This holds the stock much stronger and truer than by nailing on the surface of the
stock. Of course a couple of nails are also requisite to fix the stock and slipper together. The
length of the slipper should not exceed twice the projection of the cornice, because if longer, the
mould, in s.tarting from the angle and finishing at the other, prevents the plate and stock from
running close into the angles, thereby causing a longer length of mitre. The wedge (d) is cut to
fit the groove, but less the thickness of the stock. The handle (i-:) is cut from a square piece of
wood, and then the centre or hand part rounded off with a spokeshave, leaving about 2 inches at
the ends square, which give stronger fixing points than if made round. The handle should be
sufficiently long and fixed, so as to clear the mouldings, and allow jjlenty of room for the worker's
hand. One end should be fixed near the nib to act as a stay to resist pressure and vibration while
the mould is being run. Large running moulds require one or more stays to strengthen projecting
or weak parts of the plate and stock, and to keep the stock upright and square. The plate is now
fi.xed on the stock by means of tacks or screws, and then these combined parts are set into the
groove of the slipper, and the wedge forced home, taking care to keep the toe of the stock flush
with the face of the running edge of the slipper. Should the wedge project beyond the running
edge, cut it off flush. A couple of nails or screws are then inserted from the bottom side of the
slipper to further secure the stock and slipper. The nails or screws must be kept sufficiently back
from the running edge as to clear the running rules. When fixing the handle, a set square
should be applied upon the slipper to test the plumb of the stock. Unless the stock is square with
the slipper, it is of course not upright, and therefore it will not form the moulding to the exact size
and profile of the given cornice. The complete mould is shown at F. When there is a large
quantity of mouldings to be run, or if the screeds are hard, it is necessary to protect the wood
bearings of the running mould to better resist wear. This is effected by fixing shoes (l) on the
nib and each end of the slipper. Shoes are generally made of zinc, but sometimes of leather.
When using a slow-setting material, or one that has to be used in a very soft state for running off
mouldings, it is advisable to use a splash-board to prevent the stuff from dropping. A splash-
board (H) is about .i inch thick, and in length and width according to the size of the mould. The

312 Plastering — P/aiii and Decorative.

outer edge is cut on the slant to allow the mould to be run close to the angle. It is fixed on the
slipper and stock, as shown at t;. This shows the complete mould with the splash-board, and the
shoes on the nib and the slipper. A splash-board is also useful in preventing stuff dropi^ing and
splashing when running mouldings having a greater ceiling than wall projection.

Running Moulds for Enriched Cornice.s.— With
regard to cutting a mould plate for an enriched cornice, a
bed for the enrichments must be set out on the tracing or
the profile before the plate is cut. In some designs the
top enrichment fits on the line of ceiling, and in some a
part of the enrichment lies on a bed and a part of the ad-
joining members. It is therefore necessary to make an
allowance for this when setting out the mould plate. A bed for enrichments is made bj'
setting back the line of the profile at the enriched parts, to allow for a sufficient thickness
of the cast work. Beds for some forms of enrichments, such as egg-and-dart bed moulds,
^ need not follow the same contour as the front profile, but are made with straight beds

having the angles cut off, to reduce the quantity of fine plaster u.sed for the cast work,
only leaving a thickness or strength to enable the cast to be freely handled when casting and fixing.
Various enrichments with their beds are shown in the annexed illustration (No. 1 19). This is a
design of a cornice b)- the author which gained the first [)rize for a cornice design offered b)- the

No. 119.— SKcriON OF Cornice.

No. 120, — El.IiVAlION 0|- TklZK C'lHMi F..

Carpenter ami Builder, 1880. This shows the section with profile and bed of the enrichments. The
dotted surface indicates the thickness of the casts ; the front line is of course the profile, and the
back line is the bed. The top bed mould, soffit, and cove lie between plain members, but a part of
the lower bed mould lies over the cavctto and partly on the fascia members. For solid work, the

Making Various Kinds of Running Moulds.

313

Fi"

No.

I. Fig. :

-TwiN-Si.iPi'ERF.D Mould.

overlying part of the enrichment is cast separately, and planted after the bed mould is fixed, but for
fibrous plaster work the whole enrichment can be cast in one piece. The foregoing illustration
(No. 120) is an elevation of the cornice drawn to show the enrichments.

Twin-Slippered Mould. — Fig. i in the annexed illustration (No. 121) is a perspective view of
a running mould with a twin slipper. This form of mould is used where only one bearing or screed
is available, such as when running a moulding adjoining old work, or a skirting moulding over a
tiled plinth. The mould illustrated is for the latter purpose. The inner slipper is made shorter and
thicker than the outer one. This forms a nib or bearing for the mould and a counterpoi.se for the
outer slipper. The slippers and the stock are so arranged
that there is a sufficient space between them to allow for
the size of a running rule. A section of the mould is given
at Fig. 2, and the running rule (r) on the plaster screed (s)
is shown. The stock is let into the outer slipper in the
usual way, and rebated to receive the inner slipper. Two
handles are used, and are nailed to both slippers to steady
the whole mould.

Radius Mould. — The annexed illustration (No. 122)
elucidates the method of making a radius mould. This form
of mould is used for running circular mouldings on a bench.
A section of the mould is given at Fig. i, which also shows
sections of the \arious parts. I! is a wooden centre block,

which is fixed on a moulding board ; P is the centre pin, which is let into the centre block ; M is the
mould ; K the radius-rod ; and c the centre plate. The centre plate is made with an eye to fit the
centre pin, and fi.xed on to the radius-rod. Fig 2 is a plan of the radius-rod showing the eye of the
centre plate, also the rebate made at one end of the radius-rod to receive the stock of the mould.
For small mouldings the radius-rod is fixed at the bottom of the stock. By this way no centre
block is required — a centre pin or a bradawl inserted into the moulding board will be found sufficient
for a centre. In some districts a radius-rod is called a "trainer," and in others a "gig-stick."

Arch R,\dius Mould. — Illustration No. 123
shows sections of the various parts of an arch radius
mould, as used for running the archivolt moulding and
a panel moulding on the intrados of an arch in one
operation. A, in Fig. i, is a section of the arch. A part
of the panel moulding on the intrados of the arch is
shown. This runs parallel with the dotted line, which
springs from the springing of the arch at is. A part of the
mitre is shown. S is a running screed on the extrados ;
M is the mould ; R is the radius-rod, with the centre plate ; 1! is the radius board ; P is the
radius pin. Fig. 2 shows an inside elevation of the end of the radius-rod, with the centre plate.
It will be seen that there is a half eye in this centre plate. This allows the mould to be more easily
and quickly put on and taken off the centre pin. When the moulding does not extend below the
springing line of the arch, the weight of the running mould falls on the centre pin, whereas if the
moulding descends below the centre, the weight falls from the centre, therefore in the latter ca.se a
full eye is best. The eye should be made to fit the centre pin exactly. If too loose, the moulding
is apt to get out of a true circle, unless held firmly against the centre pin after passing the level, or

No. 122. — Radius Moi'ld.

314

Plastering — P/aiii and Decorative.

when the weight of the mould changes. The centre plate for arch moulding should be fixed on the
inside of the radius-rod, and the rod should be fixed on the mould in a line with the face of the
arch, so as to get the centre correct and the moulding plumb with the wall. For this same reason,
the radius board (on which the centre pin is fi.xedj should also be fixed on the same line.

Hanginc; Moulds. — When there arc no foundations for a
wall rule to carry the weight of the running mould, the mould, if
large, requires the application of great physical force to ensure its
running steadily and true. For instance, when running a beam
moulding on a cove, the mould being unsupported, it has a constant
tendency to drop downwards. This may be obviated by making
a "hanging mould," which is made by using two slippers on the
mould. The ujjper or wall slipper (termed the runner slipper) is
so made that it will clear the face of the running rule, and bear
on the upper edge of the running rule fixed on the vertical or top
screed. The lower slij^per (termed the nib slipper) is fixed at the
nib of the mould, and bears on the soffit or horizontal screed.
Sections of the \arious parts of this mould, and a hanging mould
for a crown moulding, are shown on the annexed illustration (No.
124). A, in Fig. I, is the constructional work or wood framing; B
and H are brackets ; P and P are the vertical and horizontal plaster
screeds ; R is the running rule ; and M is the running mould. Two
handles are generally used (as shown) for this class of mould.
Two other handles are used on the opposite sides for extra large
moulds, .s is the running slipper, and N is the nib slipper. The
latter is generally made about half the length of the running slipper. The nib slipper allows the
mould to run more easily than if run on the nib of the mould only. Fig. 2 shows a section
of a main or crown cove moulding, run from a running rule fixed on the cove.

Fig. 2 illustrates the method f)f running a longitudinal or crown moulding over a cove. The

No. 123. — Arch Radius Mould.

No. 124. — Hanoinc RuNNiNi". Moulds.

moulding is run from a main running rule and a nib rule. The sections of the various parts are as
follows: — A is the constructional work ; B the lath bracket; N the nib running rule, which is fixed
on the weathering of the moulding; R is the main running rule; M is the running mould ; ."^ the
slipper. Where the mouldings are extra large, the}- may be run in two sections. This is clone by

Making Riinning Moulds for Splayed Angles.

3':

fixing a parallel running rule on the bed of the enrichment (•£.), and running a portion from each
side of the rule. The dotted circular line at P: indicates the profile of the enrichment ; c is the back
line of the sunk panel ; and D is the face line of panel moulding.

If there are brackets for vertical mouldings in the cove which intersect with the longitudinal
bracket, the upper part of the vertical ones must be cut down to allow the running mould to pass.
After the longitudinal moulding is run, the vertical brackets are made good, and then the mouldings
are run and mitred. Another way is to fi.K a running rule across the brackets (stout flooring boards
are best for this purpose), so that the moulding can be run from end to end. By this method the
moulding is run in two operations, the main or upper portion being first run from the running rule
fixed across the brackets, and then the lower or sunk parts between the vertical mouldino-s are run
from running rules fixed on each division of the cove. In some designs each part of the moulding
maj- be run from a parallel rule fixed on a wide plain
member, or on the ground of an enrichment, as already
described.

Running Mould for Square and Splaved
Angles. — The annexed illustration (No. 125) elucidates
a simple and expeditious method of running a cornice
in a room where there are square and splayed angles
— between the ceiling and walls — intersecting together.
By this method the same running mould Twith a small
addition for the splayed angles; is used for running a
cornice in square and splayed angles, so that they will
mitre true and square with each other without altering
the members. This method is not only more expeditious
than setting out and using a raking running mould, as
generally used for splayed angles, but the mouldings on
both angles being alike in size and profile, are more
harmonious in appearance, and a graceful curve is con-
veyed to the splayed wall. The running mould is cut to
the given profile, and horsed to fit the square angle in
the usual way. After the square angle mouldings are
run, the mould is altered so that it will run the splayed
angle mouldings also in a square form, and to intersect

with each other. The section of the running mould in position for running the square angle moulding
is shown at Fig. i. a is the running rule fixed on the wall, B is the stock, c the slipper, and n is the
plate of the running mould. The same letters apply to Fig. 2. This sketch shows a section of the
running mould in position for running the splayed angle moulding. After the square angle mouldings
are run, the slipper of the running mould is taken off, and then the stock is extended in length and depth
until it touches the splayed wall line, and allows for a pleasing curve from the lower member of the
moulding to the splayed wall. This is effected by adding an extra piece of stock and plate, cut to
the desired curve, to the original stock, and fixing them together with a cleat. H is the added
piece of stock, and F is the cleat. The dotted line at F indicates the line of the original stock.
The slipper is then planed to fit the splayed wall line and the running rule A. In order to obtain
accuracy and save time, the work should be set out on paper or a board before cutting the added
stock or planing the slipper. It will be seen that about i inch of the square wall line is continued

No. 125, — RlNNING MOri.l> FOR Si'I. AVEl' AM.I.ES.

3i6 Plast eying — P/niii and Decorative.

below the bottom member of tlio moulding, as indicated by the dotted line at K. This gives a
better springing for the curve than if taken from the bead. If the moulding finished with a
square member, such as a fillet, the curve may spring from the arris of the member. It will be .seen
that by either way the curve forms part of the splayed wall. The vertical dotted line indicates
the square wall line. This is used when setting out the added stock and curve. The handle of
the running mould is omitted to .show the other parts clearer. Both moulds must be plumbed before
the running rules are fixed to ensure true intersection with each other. This is effected by the aid of
a plumb-bob, as shown on both figures.

MUFKLED Moulds. — Mouldings are roughed out with a coarse material, and finally run off or
finished with a thin coat of finer material, and in order to allow a space for the finishing coat, the
mould must be muffled ; that is, the edge of the plate or profile must be covered so as to obtain the
desired space. There are various ways of doing this. The most common is to gauge sufficient plaster,
and cover the bevelled edge of the stock, allowing it to project about ] inch be>-ond the edge of
the plate ; and when set, this is trimmed with a knife to within about j'',. inch of the edge of the
plate, following the line of profile from the ceiling line to the wall line. Another way, generally
used for small work in gauged plastering, is as follows : — First rough out the moulding with gauged
coarse stuff, and then fix small pieces of leather, lead, or zinc over the nib and ends of the slipper.
This draws the mould out from the rough coat, and gives a space for the finishing coat. For large
mouldings and the best class of work another and better method is employed. For this method
an e.xtra plate, termed a " muffling plate," is cut, the profile being cut larger, so as to project about
^ inch beyond the profile of the true or original plate. The muffling plate is then screwed on the
original plate, projecting the extra size to allow for the finishing coat. After the moulding has
been roughed out, the muffling plate is taken off, and then the fine stuff is laid on and the
moulding run off with the original plate.

Notes on Running Moulds. — Running moulds should be horsed with well-seasoned wood,
otherwise the slipper is liable to swell with the wet when running the mouldings, which may throw
the mould out of square. This applies specially to large moulds. All the wood-work should be
planed to allow the stuff to be readily cleaned off after each gauge. Rough wood retains sand,
coarse particles, or bits of set stuff, which cause furrows and rough parts in the moulding. For
special work— such as running mouldings in white cements — the wood can be prevented from
swelling by brushing it with paraffin oil. Zinc, or copper, is used for the mould-plate, to prevent
rust, when running white cement mouldings. When running mouldings in neat plaster — such as
used for reverse casting moulds — the running mould must be "horsed" stronger than for cement or
lime mouldings, to enable it to resist the swelling of the plaster.

CHAPTER XI.

GELATINE MOULDING.

Gelatine: Its Uses for Moulding — Gelatine Manufacture, Tests, Preserving, Indurating,
Dissolving— Seasoning Gelatine Originals— Shellac and Paraffin Seasoning— Seams and Blubs
IN Jelly Moulds— Oiling Jelly Moulds — Gum, Linseed, and Chalk Oils— To Make a Case-
Cases, to Secure and Separate— Gelatine Moulding— To Mould a Truss— To Mould a Bust
—Brushed Jelly Moulds— Compound Moulding Piece— Moulding Clay and White Models-
Open and Straight Moulds— Glue Moulds— Rubber and Shellac Varnishes— Soft and Spoitv
Casts— Gelatine Casts— Indiarubber IVIoulds- Fibrous Plaster and Concrete— To Make a
Fibrous Case— To Mould and Cast Balcony Fronts— Interchangeable Moulds— Combined
Gelatine and Plaster Piece Moulds.

Gelatine: Its Uses for Moulding. — An operation which the operative plasterer is often
greatly concerned about is the process of casting in plaster b}- the use of gelatine moulds. This
process is looked upon something in the light of a trade secret, but it is an open secret, for technical
literature has caused man\- to inquire into the methods, and elucidate from their friends or from
some literary source the details of the process. It is not so old as might at first be imagined. It
has scarcely as yet attained its jubilee, but it is a branch of the ])lastering art that is distinctly
honoured because of its usefulness and its perfection of work. The credit of introducing gelatine for
moulding purposes is claimed by Mons. H. Vincent. In 1 850 he produced si.x casts from one
mould, which at that time was considered a wonderful achievement. The date of Mons. Vincent's
first attempt with gelatine moulding is uncertain, but in 1847, J. Herbert, a London modeller,
produced undercut cast work from gelatine moulds. R. l-'oster, a plasterer's shop-hand, was the
first to u.se gelatine in Scotland. The initial cost and trouble is more than repaid b\- the ready
duplication of undercut work. I have seen a highh- undercut soffit, \2 inches long and 6 inches wide,
hung up in a casting shop in honour of its being the 125th of a series of casts out of the one
mould. E\cn after so man)' had been taken out, this well deserved the place of honour, as it was
a fairly clean and sharp cast. Of course the gelatine u.sed was good (B. Young & Co.'s A I gelatine'.
the oil carefully prepared, and the plaster cool. The work was done in 1871 by Messrs .A. & J.
Millar, of Edinburgh.

A process so artistic or rather so useful in the jaroduction of artistic work was not likelj- to escape
the Italian moulders, who were just finding out the possibilities of their craft in the large towns of
England. The>- soon grasped the idea, and " flexible moulds," as the\- termed them, were u.sed for
casting busts, statuettes, plaques, &c. The Great E.xhibition of 185 1, which was a revelation in the
arts and crafts of many lands to Engli.sh eyes, was also an opportunity for exemplifying this art
by the exhibition of samples of undercut plaster work which had been cast from gelatine moulds.
In the early days of gelatine for jjlastcr casting, only the most expensive kinds were used, 4s.
to 5s. per lb. being the usual price given, but these prices are prohibitor\- for general jjurposes.
Gelatine which costs less than one-half the above prices, when prepared and used as hereafter

3 "8 Plastcritig — Plain aiiil Decora five.

described, will last a considerable time, and yield good cast work. Before the introduction of
gelatine for moulding enrichments, plaster and wax were used for moulding, plaster piece moulds
being used for work on the round, and wax piece moulds for trusses and similar work. The leaves,
scrolls, &c., of highly relieved work were cast separatel>-, and then planted on the main casts.
Perforated work, leaves, patera;, &c., were front and back moulded in wax ; soffits and friezes were
moulded in wax, and then undercut by hand. Piece moulding, front and back moulds, and under-
cutting by hand, are now obviated b>- the use of gelatine. It is now also used for moulding ordinary
cast work, whether relieved or not. The originals being jointed, there is no jointing or trimming
required for the casts. Gelatine moulds being much more flexible than wax, there is less force
required to ease the moulds, and less broken casts. Wax moulds have the advantage that they last
longer when in use, and also can be kept for an indefinite time (which is useful for stock work),
whereas gelatine moulds soon dry and become hard, and require to be melted and remade if
required for future use. Unless the best class of gelatine is used, and the moulds properly treated
and oiled, they will not produce such clean, sharp, and true casts as wax moulds.

Gel.-VTINE Manufacture. — Many plasterers have tried to make their own gelatine, but with
small success. It is better and cheaper to buy it from a good maker. Gelatine is a superior kind
of glue, and is obtained from bones, hoofs, hides, cartilage, and fish skins. It is extracted by means
of acids, boiling and washing in lime water ; it is then strained, cooled, and dried. The coarse
forms of gelatine obtained from hoofs, hides, &c., are called glue ; that from skins, &c., being called
size. The strongest known glue is that made from the skins and sounds of fishes. The Laplanders
make a very strong kind of glue from the skin of a perch, their cold climate being greatly in their
favour. Here a fish skin will begin to decompose before it can be dried. They put the skins into a
bladder, which takes the place of a water-bath. They are then heated until a strong elastic glue
results. Common glue has great strength if it is not injured in the making b\' decomposition or
overheating. English gelatine and Scotch glue are stronger and more elastic than the foreign
made materials.

Tests. — There are various tests for gelatine and glue. If it is not pleasant to both taste and
smell, it will not be strong. Another simple test is to weigh a small piece of glue, say | oz.,
which has been suspended in water for twenty-four hours, the temperature of the water being not
above 50° Fahr. The glue swells from the absorption of water, and if it contains any colouring
matter, this will sink. When the glue is taken out of the water it is weighed. The greater the
increase in weight, the better the glue. If it is then perfectly dried, and weighed again, the
weight of the colouring matter can be ascertained, being the difference between this and the
original weight. Common glue is made from bones. Good glue is hard, clear (not necessarily light
coloured, however), and free from cloudiness or flecks. Good glue will not give off an unpleasant
smell after being dissolved a few days. Some of the commoner kinds are very bad in this respect,
the odour from them being unbearable. Good glue, like good gelatine, will not dissolve in cold
water, but will swell and assume the consistency of jelly. The quality of glue may be estimated by
breaking a piece. If good, it will break hard and tough, and will be starry and irregular on the
broken edge. If poor, it will break easily, and leave a smooth edge. Gelatine which is easily
dissolved in cold water is not strong. The best qualities merely swell in cold water, and must be
heated to the boiling point before they will thoroughly dissolve. They also absorb more water than
the poorer qualities. Gelatine when dissolved is technically termed jelly. This term will hereafter
be used for general purposes.

Insoluble Gelatine. — Gelatine immersed in a concentrated solution of tannic acid is

Testing and Preserving Gelatine. 319

rendered less sensitive to the action of water. Chrome-acid or chrome-alum renders jelly insoluble.
Two parts of tannic acid added to loo parts of dry gelatine will resist the action of water, or the
mould ma)- be immersed for a few seconds in (or quickly brushed with) a solution of lOO parts
water and lo parts of bichromate of potash, and then exposed to the light or sun. The compounds
formed with tannic acid and with bichromate of potash are very different from each other, but
neither of them can be properly rcmelted. The bichromated gelatine will partly retain its flexibility,
and is rendered still m.ore flexible by the addition of glycerine. Bichromated jelly is quite insoluble
in water, even in hot water, and in all known solvents. It may be advantageously used in jelly
moulds for casting Portland cement, or other slow-.setting cements. Gelatine exposed to the action
of formaldehyde in a gaseous state is rendered insoluble. A solution of paraffin wax and paraffin
oil applied on the surface of jelly moulds will render them impermeable. Glue dissolved with
skimmed milk in the proportion of i lb. of glue to 3 pints of milk will resist moisture. A glue
which stands moisture without .softening may be made thus: — Di.s.solve in 8 fluid oz. of strong
methylated spirit \ an oz. each of sandarac and mastic ; add \ an oz. of turpentine. This solution
is then added to a hot solution of glue to which isinglass has been added. Glue is rendered
waterproof by adding a small percentage of caoutchouc ; this is dissolved in a suitable solvent, as
benzoline, naphtha, or chloroform. Glue is rendered more flexible by adding A pint of spirits of
wine and i oz. of rock candy to every 5 lbs. of glue. This admixture also preserves the glue.

PRE.SERVIXG Gel.VTINE. — Soft jelly may be hardened by adding one per cent, of alum or half
per cent, of sulphate of zinc. Nitric acid prevents jelly from souring and drying quickly. Carbolic
acid added to jelly prevents it from turning mouldy or having a disagreeable smell. Linseed oil
enables jelly to resist damp. Brown sugar or treacle preserves and keeps jelly moist. Jelly
that has been frequently used maj' be improved in strength b\- dissolving it with stale beer, or
with vinegar, instead of water. A small portion of pure beeswax renders jelly tough. Glycerine
will correct jelly of its faults of drying, shrinking, and curling up. It also makes jelly tougher
and more elastic. Glycerine for this purpose need not be purified. The commercial kind is quite
suitable. Gelatine, whether new or in the form of old jell)' moulds, should be kept in a dry place.
Jelly soon begins to decompose in a damp place. The addition of a small quantity of salicj'lic acid
or boracic acid will prolong its keeping powers. By dissolving gelatine with vinegar instead of water
the resultant jelly will be rendered tougher and more elastic. Vinegar also preserves jelly.

IXDUKATIXG Solutions. — It is often necessary to indurate the surface of jelly moulds to
render them impermeable to moisture and to better resist heat and the effects of continuous casting.
For most purposes a saturated solution of alum will be found sufficient. A saturated solution is
made by dissolving alum in water. The dissolving may be hastened by heat or slow boiling. Water
overcomes the force of cohesion in certain substances, and distributes their particles throughout its
own volume, the solid form becoming entirely lost, and the result is called a solution. A solution
is said to be " saturated " when no more of the solid will dissolve in it. " Sugar-wash " is also used
for indurating jelly surfaces. It is made by dissolving li oz. of sugar of lead (acetate of lead — this
is poisonous) and 2 oz. of brown sugar to i quart of strong solution of alum. The whole is
dissolved by gentle heat and frequent shaking. When dissolved and cool, allow the sediment to
remain, pour the clear liquid into a clean bottle, and keep the bottle corked when not in use. The
mould must be dusted with French chalk, and then cleanly wiped out with soft rags or a brush, to
absorb any oil that ma\- be on the face of the mould which would prevent the solution from
penetrating into the surface. The mould is then thoroughly saturated with the alum solution or
coated with the sugar-wash. If alum is used, the solution may be freelx- brushed on the mould, or

320 Plastering — Plain and Decorative.

it may be poured on and allowed to lie for ten or fifteen minutes. It is then poured out, and the
mould wiped clean. It is then ready for oiling. If the sugar-wash is used, it must be carefully
brushed over the mould two or three times. If the jelly is soft, or the surface becomes flaccid,
it may be corrected by brushing it with a weak solution of sulphate of zinc. Two oz. of linseed
oil to each gallon of jelly will render it more waterproof

Ul.ssoLVixi; Gi:l.\TINK. — Gelatine is dissolved by means of a water-bath. Two pots are
required (the outer one for water and the inner for the jelly), like a joiner's glue-pot, only on a larger
scale, and having a lip to pour the jelly freely. The primitive plan of using two pails (a small one
placed inside a larger one) to dissolve jelly, is a waste of time, heat, and material. The open space
between the two pails allows the steam to escape too freely, instead of confining it to melt the jellj'
more quickl_\-. An old sack placed over the pail is sometimes used to confine the steam. The Imt
water should never be allowed to sink below the level of the jelly, as the jelly takes longer to
dissolve, and it may be spoilt b)' burning. Scotch plasterers have a good plan for melting jellj- and
wax at the same time. They use an iron boiler, about 3 feet long, 2 feet 6 inches wide, and 18
inches deep, having two openings on the top to fit a jellj'-pot and a wax-pot. The openings may
also be used for two jell)' or wax pots as required. Feed and waste pipes are connected at the top,
and a hot-water tap at the bottom. These boilers can be made at most iron foundries, and are
built on a brick setting, having iron bars and a door similar to an ordinarj' copper. The\- are
cheap, durable, and keep the jell\- and wax clean, free from burning, with always a ready suppl\- of
wax. The)- also supply hot water for general use, and will burn small coals. The jell)'-pot should be
made of block-tin. Jelly leaves the sides more freely, and is not so liable to cake as it does on iron.
An ordinary sized jelly-pot is about 16 inches deep and 1 1 inches in diameter. A flange is fixed
about I inch from the to]j to support the pot b)- resting on the X.o\> ])late of the boiler. The flange
is about I inch wide at the back, and increases at the front, so as to form a lip for pouring purposes.
The pot should have a lid with a hole for the stirring stick. The lid keeps out dirt and retains the
heat. Jelly-pots should be oiled before the jelly is put in, to allow any surplus jell)', after pouring,
to be easil)' drawn out, and leave the pot clean. A jell)'-pot is shown on illustration No. 88.

There are two ways of preparing gelatine for dissolving. The first is, to soak the dry material
in clean cold water until it is soft and swollen. It is now read)- for dissolving. The time required for
this depends upon the quality of the gelatine. Pour off the surplus water, and keep it for thinning
the jelly if too stiff, or for soaking more gelatine, or making size water. The other wa)- is, break
the gelatine cakes in small pieces, and place them in the pot and pour hot water over it, and allow
it to boil until all is dissolved. The quantit)- of water required may vary from a half pint to one
quart to each pound of gelatine, according to the quality. The first way is the best and quickest,
as it dissolves more easil)-. This also tends to retain the strength, as excessive boiling weakens
gelatine. Care must be taken that the gelatine is not over-soaked, because this weakens it, and a
part of the strength is transferred to the excess water. When dissolving gelatine, it should be
occasionally stirred to distribute any undissolved lumps. Gelatine should always be dissolved at as
low a temperature as possible ; about 100' to 120' F. will be found sufficient. The temperature for
remelting jelly should not exceed 1 10' F. Prolonged heating or too high a temperature will cau.se
it to speedily lose its setting and elastic powers. The pot should be taken out of the water-
bath as soon as the jelly is dissolved, as excessive stirring and heat tend to lessen its toughness.
After being taken out, the jelly should be once stirred and allowed to cool. If stirred again it will
induce air with the jell)-, and cause the mould to be " blubb)-," i.e., full of small holes. When properl)'
dissolved, it should be of the consistency of thin melted wax. When sufficiently cool to pour on

Originals for Gelatine Moulds. 321

the original, the jelly will have a thin skin on the surface. Just before pouring the jelly, a hole
must be made in this skin, close to the pouring on side or lip. .Another small hole is also made at
the opposite side to allow any contained air to escape, and the jelly to run freely. When the jelly-
pot is emptied, this skin hangs on to the side of the pot. As it often contains frothy matter, it
should be taken out and remelted for size water. Care must be taken that the jelly is not too hot
when poured on, as it is liable to stick to the original. A further guide for ascertaining if too hot
is to push the finger through the surface skin, and if it can be borne without discomfort, the jelly is
ready for use. The right heat may also be judged by ])lacing the hands on the outside of the
jelly-pot.

As already stated, glycerine renders jelly more elastic and keeps it moist. The quantity of
glycerine depends on the quality of the gelatine, and will vary from 3 oz. to 6 oz. of commercial
glycerine to each pound of gelatine. The glycerine is added to the dissolved jelly just before the
final stirring. When jelly moulds are done with, cut them up into small i>ieccs, and spread them
out in a dry place until wanted for remelting.

After being dissolved once or twice, a few drops of carbolic acid should be added to each pot
of jelly to keep it from turning mouldy. Some large originals require a dozen or even more pail-
fuls of jelly to complete the mould. In order that all the jelly may be ready at one time, a
galvanized iron tank, sufficientlj' deep to admit good-sized pails, and pierced on the top to receive
the desired number of pails, is required. This is best heated with two or more gas stoves.

Se.xsoning Originals i-OK Gel.vtine. — Seasoning is a process for maturing originals and
hardening plaster surfaces, also for stopping the suction to prevent adhesion, and give greater
freedom in taking wa.x, sulphur, jelly, or plaster piece moulds from originals. An original is
the model or object from w hich the mould is taken. Originals are also known as " solids " and
" moulding pieces." Stock originals are kept for moulding purposes. Originals for wax and
sulphur moulding require no special seasoning, but are simpl}' soaked in water when required for
use. Originals for jelly moulding are seasoned in various ways. The most usual is to coat the
moulding surface with shellac. This is the same as patent notting. Linseed oil, paraffin wax, and
French polish have been used for seasoning. Painting with shellac is a cheap, clean, and quick
process. An excellent mode is to immerse the " original " in a strong solution of borax, gradually
heating it. This renders the plaster almost as hard as marble, and it ma\- be polished in like
manner.

Shellac Se.\SOXING. — To make shellac, get an old wide-mouthed pickle bottle. Cut a hole
in the middle of the cork so that the handle of the brush will fit tight. This prevents the evaporation
of the spirit which keeps the shellac in a liquid state, and the brush soft when not in use. Fill the
bottle about one-third with dr>' orange shellac, adding wood naphtha until three parts full. Cork it
slightly, and stand it in a warm place until the shellac is dissolved. This may be hastened by
frequent shaking. Before using, try it on a piece of gauged plaster. If too thick, it will peel or
flake. This is corrected by adding more naphtha. Two coats of thin shellac are better than one of
thick. Originals should be warmed in front of a fire before the .shellac is applied, to dry them. The
semi-drj- and warm surface gives greater cohesion. A coat of linseed oil laid before the shellac is
applied hardens the surface. Shellac is useful for a variety of plastic purposes, and for general use
can be applied without any oil or drying preparations. " Shellac cement " is useful for sticking
together small broken pieces of originals, casts, &c. This cement is simply shellac in a thick form
made by evaporation, or burning the superfluous naphtha in a tin or saucer.

Oil SEA.SONING.— Originals are also seasoned by coating three or four times with linseed oil

3-2 Plastering — Plain ami Decorative.

The original must be dry before the oil is applied, because the oil and the contained moisture in
the original tends to rot the plaster. Linseed oil ma\- be used for permanent originals, as it makes a
iiard and smootii surface ; but the process is slow for general work.

P.\K.\i FIN-W.\x Skascjxinc. — The method of seasoning originals, also plaster piece moulds,
with paraffin wax, was introduced b)- the author, and has given satisfactory results. The process is
quick, and the originals and moulds can be used at once. It hardens the plaster, and renders the
surface impervious to damp. The original is first made warm, and the dissolved paraffin applied hot.
This must be done quickly and evenl\-or it will cake on the surface. The paraffin wax is dissolved
by means of a hot-water bath, as in dissolving jelly. This is safer, cleaner, and retains the strength
of the wa.x better than if dissoKed in a pot over a fire. A little ]jaraffin oil added to the wax
makes the solution work more freelj-. When cold, the original can be rubbed with soft rags or
cotton wool, which gives a smooth and polished surface. The finer the surface of the original, the
finer will be the surface of the mould. Paraffin wax being used for several other plastic purposes,
its properties are here given. It is a white, pearl)-, translucent substance. Though not affected by
the strongest acids or alkalies, it is soluble in paraffin oil and turpentine. Its affinities are so feeble
that it derives its name from this peculiarity. It has a lower melting-point than spermaceti, wax,
or stearic acid. The melting-point varies from i lo to 150 F.

Seam.S .\M) Hl.L'lss IN Jr.I.LV Moui.K.s. — Seams in jell>- moulds arc caused by using jell\'
too cold, also b)- insufficient space or \entilation for the jelly to run freely. These faults can be
avoided by the proper manipulation of the jelly and case-making. Blubs are caused by similar
errors, but principally by the force of contained air. The air is forced off, and a freer and easier
passage for the jelly obtained, b)- pouring one or two tablespoonfuls of methylated spirits down the
funnel just before pouring on the jelly in large moulds.

Oiling Ji:llv Moulds. — When jelly moulds were first introduced, their surfaces were
painted or \arni.shed, to enable them to resist the heat and moisture of plaster. Painting moulds
makes their surfaces coarse and blunt, and ha\ing to wait for each coat to dry, makes it a slow-
process, and the paint being insoluble, makes the jelly coarse when remelted. A better class of
gelatine was sub.sequently used, which by the aid of gum oils required no painting. London
workmen, as a rule, are greatly behind many of their provincial brethren in the art of gelatine
moulding and casting. This is partl\- owing to the carelessness or parsimony of some of the
employers, who still insist on the use of ordinary glue and painting the moulds. Various kinds of
varnishes have been employed for rendering jelly surfaces heat and damp proof; but owing to the
moisture of the jellj', it is difficult to obtain a perfect cohesion of the two substances. Various
gums and waxes have been used in the form of oils for protecting the face of jell\- moulds.
Mixtures of stearinc, spermaceti, wa.x, and oils have been used with varj-ing succe.s.s. Canada
balsam thinned down with turpentine makes a good oil. One of the best and cheapest oils for
this purpose was termed " patent oil " when I first introduced it. This is now simplified in the
making, and gi\cn under the name of "gum oil."

Gum Oil. — Gum oil protects the surface of the moulds, and no painting or varnishing is
required. It is made as follows : — Dissolve 4 oz. of gum damar and 2 oz. of paraffin wax together
by gentle heat, and then add li pints of kerosene (the finest paraffin oil). When all is dissohed,
pour it into a bottle, and keep it corked when not in use. Onlj- pour out as much into an oil dish
as will last a da\-, or better still, use a ball oil-pot. This oil is also used for oiling the original, and
when the jelly is poured on it absorbs a part of the oil and renders the surface of the mould more
durable and damp-proof.

Oi/s for Gelatine Moulds. 323

Chalk Oil.— Chalk oil is also used for jelly moulds for ordinary work. It is also useful for
mail)- other shop purposes. It is made by adding steatite (French chalk) to paraffin oil until of a
cream}- consistenc)-.

Pe:troleum Oil.— Crude petroleum is an excellent material for oiling jelly moulds, especially
if the jelly is old, or has to stand excessive damp, such as when casting with slow-setting cements.
Crude petroleum is about the best furniture or varnish renovator known. Having more body than
paraffin oil, it offers a greater protection against damp to soft or weak parts in jell>- moulds. Crude
petroleum is prepared for commercial purjsoses by .settling, &c. The distilled products— kerosene
oil, &c. — are so \-aluable that oilmen do not care much to market the crude, and hence it costs as
much as kerosene oil.

To M.\KE A Case. — Plaster cases are used for keeping the various parts of wax or plaster
piece moulds in position. A case for a jelly mould keeps the jelly in position, and also regulates it
to a nearly uniform thickness, so that it will easily bend and allow the ca.st to be freely taken out.
The jelly being poured through an orifice in the ca.se, it is necessary to form a space for the jell)".
The space between the original and the case regulates the thickness of the jelly. This is effected
by covering the surface of the original with a coat of clay before the case is made. This clay is
termed " thickness cla\- " (because it regulates the thickness of the jelly), and is laid as follows.
First cover the original w ith damp paper, so that the thickness clay will not adhere, dirty, or injure
the face of the original. Then beat out a sufficient quantitj- of clay about I inch thick, cut this
into strips of convenient size, and lay them piece by piece on the surface until the whole of the
original is covered, and nearly uniform in thickness. It will be understood that the sides, deep or
undercut places of the original require an e.xtra thickness of cla}', so that it can be splayed to
allow the case to draw from the clay and the jelly mould. The clay surface is then made smooth
with the hands and water (not oil). A wet brush or a sponge may also be used for smoothing the
surface. The smoother the cla\', the smoother the case, and consequently the jelly runs freer, and
the mould leaves the case more easily and cleanly when casting. After the clay is smoothed, place
round and tapered clay dots on all the high points of the thickness clay. The dots are made about
), inch thick and about i inch high, or according to the thickness of the intended case. These
dots form the vent holes, and also act as guides for the thickness of case. The vents allow the
contained air to escape when the jelK^ is poured on. Another clay dot about i ^, inches diameter is
required to form an orifice for the funnel. The funnel dot should be placed at the most convenient
place for pouring the jell}-, but it must be at one of the lowest levels or at the ground of the
original, so that the jelly while being poured in the funnel will force the air in the case up and out
at the vent holes. After the cla}- dots are all laid and smoothed, a clay, wood, or zinc fence is
fixed around the outside edge of the original to regulate the width and thickness of the rim of the
case. The rim of large cases is strengthened by bedding rod or hoop iron in the plaster while
making the case. Cases for large centre flowers are further strengthened by placing a hoop-iron
band on the outside of the rim. This prevents chipping when turning the case over while casting.
Having smoothed the thickness clay and the dots, brush the whole with soapy water, onl\- using oil
for the plaster ground of the original and plaster pieces, if any. Then pour gauged plaster over
the cla}-, keeping the plaster flush with the dots, then make up four or more plaster dots, and
float the points level with a wet board, so that when the case is turned over it will Ije level on the
casting bench. When the original is unequal in height, or much higher at one end than the other
(as for instance a truss), the plaster dots for levelling purposes ma}- be dispensed with, and onl\- the
highest and lowest points floated. In order to keep a mould with two unequal bearings level when

324 Plastering — Plain and Decorative.

casting, the low end should be propped up with a block. For most purposes a mould with the
rims level is more easily filled in than if lying in a slanting position. After the case is taken off,
clean the surface, smooth and trim the vents, and stop any holes. Then shellac the inside, and a
small part round the vents on the outside, which completes the case.

Funnels are made of block-tin or zinc, and in lengths from 6 inches to 2 feet. A few from 6
inches to I2 inches long will be sufficient for ordinary work. The diameter at the bottom end varies
from I inch to \\ inches, and increases upwards to a diameter from 2 inches to 3 inches, according to
the height. The primitive way of making and using clay and plaster funnels is in.secure and a direct
waste of time and materials. They ma\- be used for small work or temporary purposes, but metal
funnels are cleanest and cheapest in the end. Cases with deep sides require a rebated edge so as
to form a lip to support the jelly and prevent it from dropping down in the case. The sides of
long straight moulds may be kept in position by means of stiffening rules, as described later on, but
for .short or circular moulds with deep sides, the lip will be sufficient for the purpo.se. The lip is
made b>- beating out a .sheet of clay about \ inch thick, and then cutting strips about | inch wide.
The strips are quickest formed by holding a clay knife in a slanting position for the first cut, and
upright for the cut at each side of the first, thus forming two strips each with a square and a splayed
edge. Place the strips on edge on the ground of the original, and against the side of the thickness
clay, keeping the splayed edges upwards and the acute point outwards, so as to form a corre-
sponding splayed lip in the case. This is quicker than cutting a lip after the case is made. Sections
of lips are .shown in the illustration of tru.ss moulding. Take the jelly in Figs, i and 2, on illustra-
tion No. 126, as thickness clay, and the formation and use of lips will be better understood.

In large originals, or where the jelly space is thin, the jelly often runs slow!)-, and causes
crinkles or blubs on the mould's surface. This is partly due to the jelly getting cold (by travelling
over a large space, and being reduced in body thickness), and partly due to the resistance of the
contained air, and may be avoided by forming a series of small channels in the surface of the
case, each about | inch wide and \ inch deep, and running from \ent to vent, to allow a free passage
for the contained air, thus allowing the jelly to run more freely. Channels are sometimes formed
after the case is made by sinking grooves with a gauge or the angle of a chisel. They are best
formed when making the case by laying V-shaped strips of clay, cut to the desired size, on the
thickness claj-, and from vent dot to \ent dot, thus forming the sunk channels in the case. Fibrous
plaster cases are also used for jelly moulds. They are punctured so as to allow the air to escape,
thus dispensing with vents. The method of making fibrous plaster cases is described later on.

To Secure C.VSES. — Cases must be securely fastened down, or the jelly will force the ca.se
from the ground of the original, and spoil the mould. Cases are secured by placing weights on the
top, also by means of wood struts fi.\ed between the ceiling and the case. Large work is further
secured by means of a coat of plaster and canvas laid over the joint of the ca.se and the ground of
the original. All joints should be covered with plaster or clay to prevent the jelly oozing out.

Joggles. — Originals and cases require corresponding joggles to keep the case in position.
Unless the case is always put on in one position, it will injure and chip the original. Joggles should
be made on the ground of the original. This is done by scratching the parts required, and for a
further key, drive a few tacks into the plaster ground, leaving them protruding. The joggles are
then made up to the desired form with gauged plaster and putty water. These raised joggles form a
sunk joggle on the ca.se, and consequently are not in the way, and allow the mould to be freely ruled
off. Joggles should be made as large as practicable. If small, the case is apt to slip, and they are
not so strong. One of them should be made larger, or a different shape, or two should be placed nearer

Case Making for Gclaiiiic Moulds.

325

each other than the others, so as to give a distincti\e point, and save the original from injury.
This also saves time in finding the corresponding joggles. Small originals, such as flat bed mould.s.
do not require joggles, but one end of the original may be cut to a different shape, or have a sunk
mark. When the case is made, it fits all the sides and ends of the ground, the different cut end
or mark giving a corresponding form on the case, which acts as a guide for fixing. A novel form of
joggles, termed "run joggles," is described on page 388, Chapter XIII.

To Si:i'.\K.\TE Cases.— Sometimes it is difficult to get the case of the mould and original
apart without injuring the case or original. This is owing to various causes, the principal being
insufficient seasoning. If the original is too large to be conveniently soaked before moulding, wash
or cover the surface with a brush or cloth dipped in soapy water until the bod>- suction is stopped.
The ca.se is damped in the same way, the surface of both being dried before oiling. Sea.soning
with oils or shellac only stops the surface suction. Pouring jelly on too hot, or irregular oiling of
the case or the original, will also have the same effect, all of which, singly- or combined, cause the
jelly to stick to the case or the original, which makes the case difficult to .separate from the mould,
and the mould from the original. The.se difficulties can be pre\ented by avoiding the causes.
They may be cured by immersing the original and case (with mould inside) into water for a few-
minutes, or until the air bubbles cease. After this, place the original solid on a bench, and in.sert
flat wood wedges about i foot apart, and gently drive them home with a hammer until the ca.se
lifts. Should the mould stick to the original, plunge the whole into water as before. The water
only gets at the outside of the mould. Good jelly is not injured by temporary contact with water.

Gel.\TINE Moulding. — Having described the preliminary parts of the process of gelatine
moulding, pouring the jelly on the original now claims attention. Before describing this simple
part, it will be ad\isable, for the sake of continuit}', to summarise the parts together. After the
original is .seasoned, it is first dusted, and if old and drj-, it must be soaked or .sponged with soapy
water to correct internal suction. It is then wiped to free the surface from moisture, and then
carefully oiled with gum oil or chalk oil, according to the condition of the jelly. The ca.se is
prepared in a similar wa}', and placed on the original, taking care that it is laid on the right joggles
or mark.s, so as not to injure the original. The case is then secured by means of weights or struts,
and the joint stopped with clay or plaster. The funnel is then fixed with cla\-, and if large, it is
further secured with plaster. Pats of clay are then laid clo.se to each vent hole, to be readj- for
stopping the jelly when it rises through the \ents. The jell)- being dissolved and cooled to the
requisite degree of heat, is then poured steadily and regularl)- into the funnel until the jell)- rises to
the highest vents. The vents are stopped with clay pats as the jelly rises. The whole is then
allowed to stand until the jelly is cold or set. This ma)' be ascertained by feeling the jell)- in the
funnel. When sufficiently set, the funnel is taken off by cutting the jelly at the lower extremity.
The clay pats are next removed, and any projecting bits of jelly cut off. The case is then taken
off, and the jelly "tits" (formed by the vents) on the back surface of the mould are cut off. This
surface is then dusted to prevent the mould from adhering to the case when casting. Dusting is
effected b\- dipping a dry brush into dr)- plaster and then shaking the brush over the mould, so as
to sprinkle the plaster over the mould's surface. The superfluous plaster is then brushed off. leav-
ing a dry surface. The mould is then taken off the original and placed in the case. The surface
of the mould is then wiped dry with a .soft brush, or soft rags or paper, and afterwards brushed
« ith alum water or with " sugar-wash." The surface is wiped again, and then oiled with gum oil
or chalk oil, according to the class of work required. It is now ready for filling in and
casting.

326

Plasteriiii: — Phnii and Decorative.

To Jellv Molld a Truss.— Illustration No. 126 elucidates the method of jell}- mouldinj,'
a truss with its cap and foot leaf in one piece. Fit;. 1 shows a side .section of the truss, jell\-,
case, and a plaster piece on a moulding board. .\ is the truss, (; the i,n-ound, I) the case, H the
jelly, C a plaster piece, K the funnel, and the f's are \ent holes. ']"he plaster ])iece C is used to
decrease the amount of jell\-, and allow the sides of the mould to be more freelj- opened when casting.

Fi$2

No. 126. — Moi'i.iiiNG A Truss \\ rrn Gki.ati.ne.

This plaster piece is generally used when there is a plain or large fiat part in the original. It is
made before the thickness clay for the case is laid. To make this piece, first sink two or more
io"''Tles in the top of the truss cap. A section of two is .shown at c. The joggles keep the piece in
position when making the case, and also when casting. Then lay strips of clay about f inch thick
on the sides and top of the cap, keeping them close to the edge, then oil the top or end of the
orifTinal, and lay the plaster on, keeping it about li inches thick at the bottom, and tapering it up
to the top until about i inch thick. The sides are tapered to the same form and thickness. The
piece is then taken off and trimmed fair, taking care to splay the inner edges, so that it will draw
freely. The form of the splaj- is shown on the top edge of the piece at c. This piece is made the
same way as described for the end pieces, in plaster piece moulding a modillion, page 268. The
piece is then coated with shellac and re]jlaced in position, and then the thickness clay is laid, keeping
it flush w ith the edges of the piece as shown. The case is then finished as already described. It
maj' be here mentioned that the case need not be carried all over the end or plaster piece, but only
carried over about 2 or 3 inches as shown, so as to leave an opening, which forins a hand hold for
lifting the case off" the mould when casting. A lip in the case — which is continued on the sides — is
shown at L. This supports the jelly sides, and prev'ents them from drooping inwards. Fig. 2 shows
an end section of the mould and cast ; D is the case, B the jelly, L, L the lips, and A the cast.

To Mould .\ Bust. — The method of moulding a bust with gelatine is shown on Plate
XLIII. Fig. I depicts a bust of the author, modelled in 1877, b\- himself, with the aid of looking-
glasses. The bust and the base are moulded and cast separately, and then fi.xed together. Some-
times they are moulded and cast in one piece. The base .should always be u.sed when modelling
a bust, as a better idea is obtained of the general effect. When the bust and the base are
cast separate, the bust ma\' be jelly moulded, and a plaster piece mould used for the base. It
will be seen that this method is adopted in the present example. This method decreases the
weight of the mould, gives a greater opening for filling in, and more freedom when casting. By
using a plaster piece mould for the base, the inoulding is generally truer than if out of a jelly mould
with the bust attached. A plaster mould also gives better results if Keen's or other white cement
casts are required. Fig. 2 shows a front view of the bust on a moulding board covered with the
thickness clay. The dark band which extends around the bust is a clay fence, used to divide the
case into two parts. The greater part is generally' the face part, so as to keep th.c joints of the

Moulding Trusses and Bi/sfs in Gelatine. 327

mould (and the subsequent seams on the cast) on a plain part of the bust, and leave the features
and ears clear. The case for the back part should be made first. This allows the bust to be laid
flat when forming the front part of the ca.se. Even if cased in an upright position, the back affords
a firm stay when casing the front. Fig. 3 shows the same view, but with the back case made on
the clay. The dark part at the top indicates where the opening is left to insert the funnel, also
as a guide where to cut the jelly to form the two parts of the mould. This joint should be cut
in a line with the joint of the back and front cases, so that the jell)- joints will be flush with the
case joints.

The joggles are made in the thickness of the case. The jelly is not so liable to escape as when
they are made oblong in form on the outer edge of the case. The opening at the top is made larger
than the end of the funnel, to allow for a small projection of jelly, which, being at the finishing
part when being poured in, is usually partially composed of blubs or contained air. This part also
affords a "catch piece" when separating the jelly from the mould or bust. Fig. 4 shows one-half of
the case, and the joggles and funnel orifice. Fig. 5 shows the two halves of the ca.se and mould
tied up ready for casting. The rope is sometimes tied .so that it does not cross the open or filling-in
part of the mould. The method here adopted enables the mould to be hung, thus allowing it
to be turned or rolled when casting hollow casts. The tension on the rope, caused b)' the weight
of the mould when hung, keeps the joints of the ca.se close.

Brushed Gelatixe Moulds. — A novel method of making jelly moulds has been employed
b\- an American artist, who informs me that he has successfully used it for moulding statuettes. By
this method no case or clay fences are required, the jelly, in a warm state, being simply brushed
over the model until of the necessary thickness to form a mould. Not having seen this method
used, or the resultant casts, I cannot venture on an opinion on its merits, but simply give it for
what it is worth.

Compound Moulding Piece. — When a large number of small plaster casts is required
(such as beads, small bed moulds, &c.), fix from three to eight or even twelve casts on a plaster
ground, and mould the whole in one operation. The casts for the moulding piece should be clean
and sharp, and accurately jointed at both ends before they are fi.xed. This saves jointing the
subsequent casts. Two or more designs, if nearly uniform in size, may be moulded in the same
way. Three designs are given in the annexed illustration (No. 127) for other purposes, as well as
a compound moulding piece. Firstly, to illustrate the employment of natural plants (slightly
conventionalised) for enrichments, as a change from the ordinary foliage. The second purpose is to
illustrate the various methods of jointing soffits or panel.s. When modelling, a little thought will
enable a joint in continuous ornament to be made so as to cut through onI>- a few stems, or parts
having circular forms. A straight or nearly straight stem is easier to joint, also stretched or shrunk,
than one which is circular. It must not be thought, from the above, that the design is to be
sacrificed for the .sake of the jointing, but taste and ingenuity combined may avoid a complicated
joint without detracting from the design, and the modeller will have the satisfaction of seeing his
work, when fixed, free from mutilation or stunted and distorted lines, such as are often seen when
work falls into the hands of unskilled workmen, or the piecework master, or "slasher," whose catch-
word is " That's near enough," or " It won't be .seen when the rooms are furnished."

Fig. 2 shows the section of the compound moulding piece, with the section of soffits, as already
described. The ground of soffit A has a convex section. This joint (as its form shows) is called a
" square joint." The ground B has a concave section, and the joint is called a " splay jomt." The
ground of c has a straight or level section, and the joint is called a " broken joint." The dotted

32S Plastering — Plain and Decorative.

lines give the section of the ornament. When fixing three or four casts of the same design
on a ground to form a compound moulding piece, it is best to take the casts from a wax mould,
and undercut each cast by hand, before fixing them on the plaster ground. It is quicker to
cast three or four Icnsrths of an enrichment from a wax mould, because there is no seasoning

No. 137. — CoMrouNi) Moulding Pif.cf. for Gelatine.

of the cast, or waiting for jellj- to cool ; and generally the first casts out of a wax mould are
sharper than those out of a jelly mould, unless one has the best workmanship and materials. If
the wax mould has to be taken from an undercut model or original, stop it down with clay or \-ery
weak gauged plaster. In the latter case, the parts must be soaped to allow the stopping to be
removed after the mould is made. The undercutting of the casts by hand and the touching u]j
can be slightly varied in each cast before being fixed on the ground of the moulding piece, and
should be either done by the modeller or an artistic shop-hand, so as to give a freshness and
crispness to the whole, combined with a well-balanced variety of detail. One end of this mould-
ing piece is splayed to show that it is not necessary to have straight sides or ends, and that
whatever form of joint the casts may have, the plaster ground of the moulding piece can be made
to suit it, taking care to avoid acute angles, because jelly running to a thin point or angle is apt
to dry, and consequently shrink or curl up. This moulding piece being flat, and the casts not

Moulding Enrichinetits in Gelatine. 329

large— taking them as being about 9 inches long and 2i inches wide— no case would be required,
only wood fences for the sides and clay fences for the ends. If the moulding-ijiece is a stock-
one, the side and end fences may be cast with the original. This makes a solid and permanent
fence, as shown bj- the section at D, Fig. 2.

Stock moulding pieces are those which are kept to be used for other works. The same
design is sometimes so often used, that one would think that there was no obtaining a new one.
no modeller to design and model one. The only stock moulding pieces that should be tolerated
are classical works, such as the caps and the small enrichments of the five orders, antique figures,
casts from nature, and masterpieces of design and execution, — these to be kept more for reference
than for use. Some of the modern cornices, with two, three, and four enrichments, are repeated ad
nauseam, and without regard to style and position. All enrichments should be designed to suit
the height intended, and harmonise with the requirements and style of the construction.

Moulding Clav Models. — Several jelly moulds may be taken from a clay model without
fear of injury to the model. The ground of the model should have a few flat-headed nails
projecting above the surface to give a key for it. Should the model spring open at the surface
joint, the cla)- must be carefully fixed by means of screws, and the holes stopped. The clay, when
firm, is then carefully brushed with thin shellac. If the model is flat, it must be oiled and moulded
in the usual way. If the model is deep, or if it is not desirable to make a case for fear of disturb-
ing the model, a case may be made after the jelly is poured on. This is done by making a
strong fence to retain the jelly. After the jelly is poured on, and allowed to cool, then remove
the fence, and cut the excess jelly off, so as to allow the case to draw. The jelK' surface is then
brushed with a solution of clay, and the plaster poured on as before. Cutting the jelly in deep
parts may be partly avoided by placing pieces of clay in the mould while soft, so as to displace the
jelly. The clay pieces are taken out when the jelly is cool. The clay pieces are formed to the
desired sizes before the jelly is poured on, and they should be firm and oiled before placing in the
liquid jelly. Large pieces must be supported by means of wire to prevent them sinking on the
face of the model. This process is useful where only a few casts are required. Owing to the clay
having little or no suction, a jelh" mould leaves a clay model much more easily than from a
plaster moulding-piece.

Moulding White Models. — Sometimes a jelly mould is required to be taken from a white
plaster or white cement cast, such as a bust or a plaque, without discolouring the model. This
ma)- be done b\- carefully brushing the surface with a solution of fine white curd or Castile soap.
Care must be exercised that the surface be not too wet or too drj- when the jelly is poured on. It
is best to mould it when the surface is semi-moist, and has a glossy face. No oil must be used, and
the jelly must be new and clean. After the mould is taken off", the model is wiped clean with a soft
sponge dipped in warm water, and when dry it will appear as if untouched.

Moulding Casts.— It sometimes happens that a few undercut casts are required from old
work, and that there is no stock original to be had. In this case it will be necessar)- to take one
cast from the old work, and then clean and shellac it. It is then temporarily fixed on a plaster
ground, with thin plaster or soft cla\- to keep it in position, and prevent the jelly running under
the cast. A clay fence is fixed around, and moulded with jell\- in the same way as described for
open gelatine moulds.

Open Gelatine Moulds.— Jelly moulds do not always require a case, but they may be
made the same way as wax moulds ; and if there are only a few casts required, wood or plaster fences
will not only prevent the escape of the jelly, but act as an open case or support to the sides or ends

330 Plastering— Plain and Decorative.

of the mould when casting. This is done in a similar \\a\- as described for front wax moulds. If
the model is large or deep, and much undercut, the mould may be made in one piece, and the jelly
afterwards cut to form a piece mould, to allow the cast to be taken out more freely. Models with
long or large flat surfaces should be moulded open — that is, without a case. If there are circular
casts required of the same model, in addition to straight casts, the mould having a level back can
be bent to any curve by laying it on a cradle or a saddle made to any desired curve.

Straight Mould.s. — When casting long casts, such as panels, friezes, or mouldings, out of a
gelatine mould, there is sometimes a difficulty in keeping the outer edges straight or level, which
causes crooked casts. This is owing to the swelling of the jelly when the mould is new, or the
shrinkage, if old. The edges are also liable to get torn by frequent handling when casting. The
use of tacks or small nails dri\cn through the jelly and into the case to keep the jell}- in jjosition
has already been e.xplained, and it answers for small work, or if a few casts are only required. A
stronger and more reliable method is to strengthen the edges of the mould with laths or
running rules. These are termed " stiffening rules." The method of construction is illustrated
later on.

Glue Moulds. — In some London shops glue is used for moulding undercut models. Glue is
used as a substitute for gelatine, principally because it is supposed to be cheaper. The first cost is
cheaper, but it does not follow that it is cheapest in the end. Glue may be used for casting large
pieces of fibrous plaster work, or where the work is not required to be fine or sharp. Glue moulds
are generally coated with a paint composed of gold size, patent driers, white lead, and linseed oil,
thinned down with turpentine. This paint is also used for jelly moulds when casting Portland
cement work, especially if the jelly is old or the cement slow in setting. It must be borne in mind
that the originals should never be oiled with sweet oil, because it prevents the cohesion of the paint
with the mould, and retards the drying. Some shop-hands use an oil composed of white lead, linseed
oil, and turpentine, for oiling the original. This is intended for two purposes — first, to stop the
suction of the original, especially if the original is composed with fibrous plaster ; and secondly, to
prevent the glue from adhering to the original, and also, " with good luck," to settle as a paint on the
surface of the mould. It may here be pointed out that the suction of fibrous originals is best
stopped by first plunging them into water for a few minutes, or if too large or too thin on the
surface to stand soaking, the front surface should be sponged with soapy water, and then the back
brushed with a thin solution of clay. The clay keeps the moisture in the body, and prevents the
suction of the porous plaster, and counteracts the heat of the jelly. After this, lubricate the original
■with a chalk oil, and the glue mould will leave the original freely and clean. This use of lead oil is
a slow and dirty process, as it has to be washed off the original every time a mould is made.
Painting glue moulds is also a slow and dirty process. The paints peel with e\ery third or fourth
cast, and require patching, and then waiting until dry. Painted moulds produce blunt and poor
casts. Glue may be improved by any of the methods used for jelly. Old glue, like jelly, is
improved by using stale beer, vinegar, or milk instead of water for dissolving purposes. Wash-
ing the face of the mould with paraffin oil before painting or varnishing indurates the surface.
A limited number of casts may be obtained from glue moulds by using the best Scotch glue, and
■working it as described for jelly mould.s. The use of a quick drying and elastic varnish gives far
better results than oil paint. The following are the best known : —

Rubber Varnish. — Dissolve indiarubber shavings in naphtha in a close ves.sel by means of
gentle heat (or a hot-water bath), then strain the liquid off into bottles, and keep them corked until
required for use. Before varnishing the mould with this solution the surface must be dried by

Moulding Enrichmeiifs in Glue.

JO'

dusting with French chalk, to absorb any surface oil or moisture which would prevent the varnish
from adhering to the ghie surface.

Coi'AL Varnish.— A good varnish is made by mi.xing i gill of copal varnish with about i oz.
of patent driers. The latter is thinned down with turpentine before mixing with the copal varnish.
The mould is dusted as before, and then \arnished, and allowed to stand until drj'.

Shellac Varnish.— This is made as follows:— loo parts water, 12 parts best hard .shellac,
and 4 parts of borax, are dissolved all together in close vessels by gentle heat and continued
stirring. The vessel is then covered, and the liquid allowed to cool, after which it is poured into
bottles which are well corked. This is used alone or mixed with a small portion of lin.seed oil and
a few drops of turpentine. The whole mass is then well incorporated, and it will dry in fifteen or
twenty minutes. Glue and jell>' moulds that are used for casting with hot plaster or Portland
cement are apt to become soft and sticky at the prominent or weak parts. In this case the moulds
should be allowed to stand in a cool place until the parts are firm. They are then revarnished or
washed with bichromate of potash as already described. Varnished moulds are oiled with chalk oil.

Soft Casts. — The surface of cast work taken from glue (and sometimes jelly) moulds is
often partly or wholly covered with soft, sticky, or spongy parts. This is caused by hot plaster
dissolving the surface of the jelly moulds, and dissolving or weakening the paint on glue moulds, thus
preventing the plaster that is in contact with these parts setting as quickly as parts where the jelly
or paint better resists the action of the heat. Soft parts on cast surfaces are also caused by using
weak or slow-setting plaster, which takes longer to set on the face of the mould than that at the
back or outside of the cast which is exposed to the air. Soft and spongy casts can be prevented
by using alum water, which not only accelerates the setting and hardening of the plaster, but also
hardens and preserves the face of the mould. If the plaster is very weak, or extra .slow in .setting,
or the glue weak, and apt to spoil the cast, then use extra strong alum water, or a larger proportion
of the ordinary alum water. This may cause the plaster to set too quickly, in \\ hich case add size
water to regulate the setting. The addition of from i to 2 per cent, of sulphate of zinc will also
neutralise the slow setting of the glue. Sulphate of zinc also indurates the mould and hardens
the cast. The combination of two materials, each having opposite effects, the one hastening
and the other retarding the setting of the plaster, may at first seem detrimental to the « hole ;
but this is not so, as while regulating the quick and slow setting powers of each other, each has a
separate hardening power, and when combined give still greater hardness to the plaster. This
method is often used when casting fibrous plaster work.

SroTTV Casts. — Solid and fibrous cast work are both liable to be spotty, or have a
discoloured appearance, more especially if produced from a painted glue mould. This is due to
various causes, but principally to sulphur or lime, or both, in the plaster, drawing the oils from the
paint and the glue to the face of the casts. If the plaster contains much sulphur, or if the alum
used for gauging is not cleanly dissolved, they will discolour the plaster. Inferior or impure oils
will also discolour the face of cast work. These bad effects may be prevented by mixing a little
chloride of lime in the water used for gauging. The proportions vary according to the kind of
plaster used, but are about i lb. of chloride of lime to 50 gallons of water.

Gelatine Casts.— Shop-hands are sometimes called upon to mould and cast parts of the
human body for surgical purposes. The following is the process as practised at the Royal
Infirmary, Edinburgh.

Preparation of the Material.— Take of Nelson's " No. i " gelatine, say 6 oz. (by
weight), soak it till quite soft and swollen, afterwards dry it slowly until just pliable. As it has

332 Plastering — Plain ami Decorative.

now the minimum of water necessary, melt it in a water-bath, and add 6 oz. (by measure) of clear
glycerine (not necessarily purified). When the two arc thoroughly mixed, the material is ready.
To render it opaque, add, while it is still hot and therefore fluid, small quantities of a thick paint
made bj- rubbing up oxide of zinc in glycerine. When a skin colour is wanted, a little vermilion
is required to give a warm life-like hue. Should other things be cast, the prevailing colour can be
given with water-colour as required (tubes of moist water-colour sold at twopence each will be found
convenient). Several pounds of this may be made at once, and portions used as required.

M.VKING THE Mould. — From the part to be cast a mould in plaster of Paris must be taken
in the ordinary waj-. It will be found best to limit tlie casts to those whose moulds can be
removed from the living body or organ in one piece. When both sides are moulded at once, the
gelatine cast is b)- no means easy to extract from the mould. After the mould has been removed
from the bodj-, it must be .slowly and thoroughl}- dried. If the mould be moist, the gelatine cast
is softened ; if too much heated, the plaster itself crumbles. Besides the thorough drj'ing, no other
preparation of the mould is needed, but for convenience the margins should be banked up with clay
before the cast is made.

Making the Cast. — Melt the gelatine and glycerine j^reviously prepared, and pour it into the
dried and banked-up mould, being careful to roll the melted mixture backwards and forwards well
over the face of the mould, so as to get rid of air bells. As the heated substance tends at first to
run into the hollows, and lea\e the raised parts of the mould with a \er)- thin coating, the operator
must keep ladling up from the hollows, and as the substance cools, it will become sufficient!)-
tenacious to remain on the upper parts.

Making a Plaster Bed for the Cast. — While the cast is still in position in the mould,
its reverse side must be co\-ered with lint or wool, and this in turn covered with plaster of Paris, either
pure or mixed with cotton wadding, oakum, lint, wood-wool, &c. This must be made to fit into the
hollows and elevations of the back of the cast, and when set, it is to be removed so as to be dried.
The cast can now be easily drawn or rather peeled out of the mould, and it will be found to be an
elastic cast of what is wanted. When placed upon its plaster of Paris backing, it will preserve the
shape which it had while on the mould.

To Paint the Cast as Required. — Use water-colour when a dry surface is to be imitated,
oil-colours when the surface is moist. The water-colour may require several coats. Finally,
an edging of black velveteen or other material will InVle the irregular margin, and give a finish.

The advantages of this method of casting are its likeness in appearance and texture to flesh,
and the great number of copies which may be taken from the same first mould. The disadvantages
are the probability that it will not keep really good for more than five or six years, and the greater
time required to make a cast in this than in ])laster.

Indiarubher Moulds. — Indiarubber has to a small extent been used for forming flexible
moulds for casting undercut work and casts on the round. In 1875 G. Haseltine obtained a patent
for flexible moulds. According to the specification, the model is first coated with a solution of
indiarubber in benzine. This soon dries, and forms a sticky surface. Laj-ers of vulcanised rubber,
about gV inch thick, and cut into convenient sizes, are then pressed on the sticky surface. This is
repeated until a body about \ inch thick, or as thick as will resist inward pressure when casting.
If the work is on the round, the mould is cut at one side to release the model. If desired, the cut
part can be securely joined again with rubber solution. The mould may also be held in its true
form by a plaster case. Before using the mould it must be vulcanised. This form of rubber
mould may be used for casting plaster or cement work. The durable nature of rubber moulds

Fibrous Plaster and Concrete for Fireproof Construction. 333

enables them to be kept for an indefinite time, and they may be advantageously used for stock
designs, especially for cement work, but their price is prohibitory for general purposes.

Fibrous Plaster and Concrete for Fireproof Construction and Decoration.—
This subject, being quite apart from that of gelatine moulding, may not appear to be in its proper
place, but owing to the numerous and varied processes and materials that are used in plaster work,
it is confessedly difficult to give an e.xhaustive description of each subject under one heading ;
therefore this, like others which are inseparable from other subjects, is given where occasion
demands. Another reason is, that part of the sketches here given to illustrate gelatine mouldings
also serves to illustrate the above subject. The various parts of fibrous plaster, concrete, and jelly
moulding are shown in the following illustrations.

Balcony Front. — The annexed illustration (No. 128) shows a combined section and elevation
of a balcony or box front for a theatre or music-hall. A small portion of the constructional work

- -jy-v Si

mm^fm?m^m..^^*m*^Mm

No. 12S. — Combined Section and Ei.Ev.vrioN of .\ Fibrois Plaster Balcony Front.

is shown to illustrate a method of constructing concrete in conjunction with fibrous plaster for
fireproof or correctly speaking, fire-resisting purposes. Fireproof construction is now, to a certain
extent, compulsory, and being essential for the common welfare, everj' item, however small, should
be of interest, and prove .serviceable to constructive and decorative plasterers. The section shows
a small part of the iron work. A is a side view of the end of a cantilever that springs from, and
is supported by, the main walls ; J shows the section of an iron joist, which is placed longitudinally
between the cantilevers, and fastened w ilh angle plates and bolts. The iron work is enveloped
in concrete to protect it from heat and fire. E, E, and E are "fixing bars," which are made with
a specially prepared concrete, and laid in position on the centring before the rough concrete is' laid.
It may here be stated that fixing bars are continuous in length, whereas "fixing blocks" are placed
at intervals. The method of making both is described in Chapter XI.\.

T is a section of a half of the top rail. This is formed with concrete and a T-iron in the centre.
E is a fixing bar. The rails ma\^ be supported by iron posts or standards. C is a fireproof jjartition.

334 Plastcying — Plain and Decorative.

constructed with metal lathin^^ plastered on both sides with concrete. This should be done before
the fibrous work is fixed. The metal lathing is fi.xed at the upper and lower edges, which are
let into grooves w hich have been previously formed in the concrete rail and floor. The partition
can also be cast, and then fixed in position while the rail and floor are being formed. The rail
can also be cast if required. When made in situ, a wood frame or box is formed around the joist,
the top being left open to allow the concrete to be laid and rammed. The floor is formed in
a similar way. The floor, partition, and rail can be formed in one monolithic body if required.
This process would necessitate extra framing and a thicker partition, to allow the concrete to pass
freely between the framing down to the floor. The main body of the floor is laid in the usual
wa>-. 1) is the flooring boards. They are fixed direct to the concrete to render the wood less
combustible, and to avoid an intermediate space, which, in this position, would in a measure be
a harbour for dirt and vermin, if not foul air. The board at D is removable, and the channel
underneath it is a bed for water pipes, electric wires, &c.

K to F shows the surface section of the fibrous plaster box-front. The diamond hatching
indicates fibrous plaster. The sections of enrichments are here omitted, but are shown on the
casting moulds. C, is a part of the soffit. This is set out so as to cover the joint of the box-front
as shown, and is fixed to the fixing bar E. The top of the rail (ll) is made of wood, and rebated
to form a lap joint over the fibrous plaster. The top can also be formed with carton-pierre or with
papier-mache, and then stained and varnished or polished as required. These materials are
superior to most woods in point of resistance to fire. The fibrous front is secured by screws,
which pass through the frame and fixing laths in the cast, and into the fixing bars in the concrete.
The weight of the fibrous front is, in this instance, supported by the ledge on the concrete floor,
therefore screws at wide intervals in the three fixing bars will securel}- hold the front in position.
The upper and lower mouldings (especially for balconies with many and various curves) are
sometimes run in "solid plaster," and the main panel and the enrichments cast in fibrous plaster.
The enrichments are sometimes cast in plaster, carton-pierre, papier-mache, and in composition.
Fibrous plaster has the advantage that it can be made lighter and in larger sections, also fixed
with greater expedition than any of the above materials.

This fibrous front would be jointed at the centre of the circle panel, these circle panels being
cast separately, and when fixed they cover the long vertical joints on the main casts. The
grotesque head is added after the centre panel is fi.xed. The lower bed-mould (L) is jointed
through the egg, as indicated by the dotted line, which is the joint of the main cast. This centre
egg may be cast separately and fixed after the main cast. This enables the main cast to be made
with a straight joint. The foregoing details will enable the general construction and fixing of the
work to be better understood. With regard to the moulding piece, a running mould is cut to
the section from F to F, taking care to allow a bed for the bottom enrichment (L), and the top
enrichment. The main panel extends from one circle panel to the next circle panel, and the
depth is the space shown by the dotted line from dart to dart. These items are here gi\en for
future reference. A sufficient length of the section is run, and on this the ornamental work is
modelled. The bust of Sarah Siddons has been chosen for this panel, because she was not only the
" Queen of Tragedy," but also, like Sarah Bernhardt, the great French tragic actress of to-daj-, she
had great talents as a modeller. She modelled a bust of her brother, John Philip Kemble, in the
character of Coriolanus, a statue of Brutus, a bust of President Adams, and many other works
of art. The other panels required to make up the circuit could be enriched with busts of other
Thespian and musical celebrities and men of letters. It will be seen that the bands between the

Moulding and Casting Balcony Fronts. 335

eggs in the enrichment (L) can be used in two separate forms. They can also be used together,
so that the bands will turn in and out from the eggs alternately. The method of making the circle
panel is as follows : —

CONX.^vo-CONVEX Mouldings.— The section of the circle panel, on plan, is the same as the
section of the main panel (shown in the previous illustration;, and is termed " concavo-convex,"
i.e., concave one wa>', and convex the other. This form of moulding is made on a plaster ground,
having the same contour as the desired concavo-convex panel. The section of this ground is shown
at .\, Fig. I, in illustration No. 129. This ground is run with the same running mould used for
running the main part of the model, but it must be slightly altered before running this ground.
This is done by fixing two pieces of sheet-iron or zinc on the original mould plate, one at the
bottom to cut off part of the moulding (as shown by the dotted line at D), to allow the slipper of
the panel running mould to pass and run on the same line of .section as the nib, thus forming the
panel moulding to a regular curve ; or, in other words, forming the whole width of the moulding at
this part to the section of the main panel. The other piece of iron is fixed in a similar way to cut off
the moulding at the top of the main panel as shown by the dotted line at E. This is done for the same
reason as alreadj' mentioned, as well as to obtain a more graceful side section, and less projection at
the crown of the circle, to allow for a proper section for the grotesque head, as shown at C on Fig. 2.
The dotted lines at D and E represent the parts of the upper and lower mouldings that spring from

No. 129. — RlNNI.NG CoNCAVO-CoNVEX MOLLniNGS.

the main panel. The running mould for the circle panel moulding is so constructed that it will
fit the various curves. This is done by rounding the nib, and using a short and oval-shaped slipper,
so as to ha\e a small bearing. The radius-rod works on a pin, which passes through the " slot,"
to allow the mould to take the up and down curves. A centre plate is fixed on the centre end of
the radius-rod. A centre hole is made to fit the centre pin. This plate is made of flexible metal
(a piece of hoop-iron will answer the purpose"), to \-ield with the rising and falling of the radius-
rod and mould. Fig. 3 shows the mould with the radius-rod. The mould is shown in two
positions (one at the concave and the other at the convex) on the ground in Fig. i. B is the
centre block and pin ; c is the centre plate. The centre block is raised to equalise the height and
depth of the two opposite curves. When running the inould, the centre plate should be kept down
on the centre block to obtain a uniform radius. The mould should be made so as to run about i inch
of the background ; the space shown by the line from H to A on Fig. 2. The remainder is made up
by hand and the aid of a template. After the circle moulding is run, the straight mouldings
at each side of the circle panel are made up to the original section, or in other words, to butt
against the circle moulding as expressed by the dotted lines at D and i:. This making up is
simply putting on what was taken off the original section, and is done to allow the panel to
be moulded to the section of the main panel, so that the panel casts will fit with a close joint
when fixed on the main cast. After this a part of the top rail should be fixed in position, as shown
at II on Fig. 2. This gives a ground for modelling and moulding the grotesque lion's head, also a

536

Plastering — Plain and Decorative.

better idcd of the general effect when modelling. Before commencing the modelling, the circle
panel and the main part of the front should be placed upright and temporarily fixed, so that the
work can be viewed as a whole, and in a similar position to the permanent one.

Moulding B.\lconv Fronts. — The moulding with jelly of the balcony front now claims
attention. Illustration \o. 130 shows sections of the moulding piece, jelly mould, and a fibrous
plaster case. -V is the ground, and r. the bocl\- of the moulding piece. The back section
of the body is the same as the structional work of the balcony front, or as shown on the
previous illustration. The moulding piece can be made in two ways. The first way is done by
running a sufficient length of ground to take two or more lengths of the original cast to be fixed
on it, allowing a space at each end for moulding purposes, this space being equal to the thickness
of the jelly and case. The original cast with the modelling is moulded, and as many casts got out
as required for the moulding piece. The casts are then fixed on the ground, taking care to leave
both ends jointed. The second way is to make up the ground at the sides and ends of the original
cast, so as to make a moulding piece. In most works the back section need not be fitted so
accurately as here shown. This example is given to illustrate the method of obtaining a perfect fit
or bed where required. A fixing point at the top and bottom of the cast is sufficient in most
cases. It will be seen that the first method is similar to making an original for a small bed-
mould, &c. Large claj' models of this nature should be moulded direct from the claj-, so as to
retain all the modeller's original touches and effects. This process dispen.ses with waste moulding

No. 130. — Section of Mori.DiXG Piece, with Jelly Mould .vnd Fibrous Plaster C.\se ok Balcony Front.

and cleaning up. A novel method in connection with moulding balcon)- fronts, or other long jelly
moulds, is that of using wood rules, termed " stiffening rules." They are used as a substitute for
the lips, which are generally formed in solid cases to keep deep or long sides of jelly moulds in
position, so that the\- will keep straight, and \ield straight casts. The use and method of making
stiffening rules, in conjunction with a fibrous case, is as follows : —

Stiffening Rules. — Stiffening rules are used to hold long sides or other straight parts of
jell)- moulds in position, so that thc\- will be stiff and straight, and prevent twisting or drooping,
thus ensuring true and straight casts. Stiffening rules arc a part of the mould, but an allowance
for them must be made when making the case. Stiffening rules are made of pine boards, and are
about I inch wide, | inch thick, and in lengths as required. They should be planed on all sides,
and tapered on the sides that project or fit into the case, so as to allow the case to draw from the
mould, and vice versA. When making the case, the stiffening rules are laid on the ground about
i inch from each side of the model, and then the thickness clay is laid in the usual way, taking
care to lay it about I inch over the rules, which leaves a i-inch bed in the case. Take E in
illustration No. 130 as thickness clay, and this process will be more clearly understood. R and R arc
sections of the stiffening rules, showing their positions and splayed edges. It will be seen that one
side beds into the case, and that the other side and the greater part of the top is bedded into the

Fibyous Plaster Cases for Gelatine Moulds. 337

jelly. Stiffening rules also enable long or large jelly moulds to be taken more easily off the original,
and with less risk of the mould tearing. This simple but useful method was introduced b>- my son,
James Millar.

To Make a Fihrous Plaster Case.— The introduction of fibrous plaster cases is of recent
date, and was invented by Tom Sweeney, formerly an employee of Messrs G. Jackson & Sons, but
now shop foreman for Mr J. Rule, of Sunderland. They are of advantage for large moulds, as,
being lighter than solid cases, they are more easy to handle when casting. Instead of a large
number of vents, as required for a solid case, one vent is generally sufficient for a fibrous case. A
passage for the air is obtained by puncturing the surface. These punctures, while allowing the air
to escape, will not allow the jelly to do so. This process is not only cleaner, but is also quicker
than forming clay dots for the vents when making a solid case, and stopping the vents when
moulding. The method of making a fibrous case is elucidated in illustration No. 130.

Having laid the stiffening rules in their positions, the thickness clay and the clay dots for the
funnels (F and F) and the vent (v) are then formed. The vent should be midway between the
funnels. For a mould this size (about 7 feet long and 3 feet wide) four funnels will give better
results than two, because the jelly is not so apt to cool and crease, by travelling over a long surface,
as when four are used, by which the intermediate space is decreased. For an original of this
section, funnels should be placed on both sides, so that the jelly will run up on both sides to the
vent. If they were placed on one side only, the jelly would run up to the top of the original, and
then down on the other side. The latter part is bad in practice, because when the jelly runs
down it is liable to retain a part of the contained air, thus causing blubs in the mould ; whereas,
by running up, the jell}' forces the air up and out at the vents.

A fibrous plaster case being very thin (from | inch to | inch thick in most parts), it is neces-
sary to strengthen it with strong laths, and in order to form a background, so that the mould will
lie true on the bench when casting, two deep frame laths are required. They also support the case.
These laths are laid from end to end of the case, and are inserted while the case is being made,
and they are further secured by means of wood stays and rib laths, which are laid crossways, so as
to bind and stiffen the longitudinal laths. Thej- are fixed with plaster and canvas, and in some
instances with screws or nails. Where practicable, the frame laths and the rib laths should be
nailed together before they are inserted in the plaster and canvas. This nailing together makes a
frame, which is laid on while the case is being made, and is much stronger than if laid in parts and
fixed with plaster and canvas. After laying two coats of plaster and canvas (one coat will suffice
for small cases), the rim laths (R L and E L) are laid, and then the overlapping canvas is turned
over and brushed with plaster. The body laths (the five C's) are then laid and covered with canvas
strips and plaster brushed. The frame laths (D and o) arc next laid. Two ways of fixing arc
shown. One is laid on the rim lath (r L), and is fixed with brushed canvas strips ; the other is laid
against the rim lath (E l), and fixed with nails. The frame laths are further secured by rib laths (G)
which are placed at intervals about 3 feet apart, and fixed with nails or brushed canvas strips, and
further supported bj- the stays (s and S . The upright stay (l) supports the bod}- lath beneath,
and offers a fixing point for the angle staj-s to support the remainder of the body laths. The top
points or bearings at the frame and upright laths, the vent and bod}- lath, are floated level. The
fibrous plaster is indicated by the diagonal cross lines. The rim body laths vary in size from i inch
to 1 inch thick, and from i inch to z inches wide ; and the frame laths from i inch to \ inch thick,
and the widths as required. It will be understood that the plaster and canvas and the laths are
laid and brushed as described for plain fibrous plaster panels. When the case is taken off the

338

Plastering — Plain and Decorative.

original it is cleaned, and then punctured. This is done with a fine and sharp pointed bradawl,
stabbing it from the inner surface, so as to leave the perforations clean, and without ragged edges.
The perforations are made at random about i inch apart, and near the highest points, or where
vents would be made in a solid case. The case is then seasoned with shellac in the usual way, and
then the stiffening rules are inserted, and it is ready for use.

Before laying the case on the original, the stiffening rules must be temporarily fixed in the
case beds to prevent them moving out of position, or falling while turning the case over and fixing
it, also while the jelly is being poured on. The rules are fixed with a solution of clay, or with
screws inserted through the case from the outside. It is very difficult to place them trulj' on the
ground of the original, therefore the latter way is the best. This done, the case is oiled in the

Xo. 131. — Seltio.n or Ji;li.v Mould of Balcony Front.

usual wa\', but taking care not to oil those parts of the stiffening rules that the jelly covers, as
otherwise the jelly would not adhere to the rules, which would render them useless for the desired
purpose. The mould is then made in the usual waj-, and when the jelly is cool the screws are
extracted to allow the ca.se to be taken off and leave the rules as a part of the mould. The next
part of the process is the casting, which is done as follows : —

C.VSTING B.\LCONY FRONTS. — A section of the casting mould is shown in illustration No. 131.
A is the ground line at the ends of the case and from which the back surface is ruled off. B is
the section of the face surface, the outline of the ornament being in the jelly thickness. The
sections of the various case laths and the stiffening rules correspond with those in the previous
illustration. Illustration No. 132 shows the section of the cast. A and .\ are wood blocks

No. 132. — .Section of Cast of Balcony Front.

which are used to support the overlying edges of the cast and prevent it from warping while it
is drying. The casts are made as fibrous cornices, but the laths are stronger to carry the weight
of the larger casts. F and F are frame laths, each 3 inches wide and f inch thick, c is a body
lath (but laid flat for fixing purposes). This and the body laths B and B are 2 inches wide and i
inch thick, and R is a bracket \ inch thick, and cut to fit over the body laths. The brackets are
placed from 2 to 3 feet apart. The cast is strengthened by nailing the frame laths and the enrl
brackets together so as to form a complete frame. This is placed on the mould after the plaster and
canvas is laid. The canvas margins are then turned over and brushed, and the body laths and
the intermediate brackets laid in between the frame. The whole of the wood work is canvased

Circular and Interchangeable Gelatine Mouhls. 339

and brushed with an extra thickness of plaster, as shown on the back section of the cast, to enable
the work to better resist fire.

Casting i.\ Large Gpxatine Moulds.— When fining in this or other large jelly moulds
for fibrous work, alum water must not be used in the firstings. Alum water is only used for small
work or for solid casts, to hasten the setting of the plaster, so that the cast can be quickly taken
out of the mould before the plaster begins to heat. Alum tends to increase the heat of the pla.ster,
therefore this heat, when filling in large moulds (which sometimes require from one to three hours
to fill in), would injure the face of the jelly The heat is avoided by using size water in the
firstings. This also gives time to lay and brush the canvas. The firstings must be gauged stiff,
only using as much size as will cause it to set just a little before the seconds sets. Alum and
size water combined — as used for " soft casts " — is often u.seful for this work.

Circular Balcony Fronts.— Balcony, box, or gallery fronts are .seldom wholly straight on
plan, but more often contain circular parts— in fact some have no straight parts, for instance, the
horse-shoe plan. Great expense would be incurred if a separate moulding-piece and mould were
made for each curve. This is avoided by recasing the straight jelly mould, so that it will produce
casts to fit any curve or combined curves. The recasing is accomplished as follows : — When
laying the thickness clay to make the case for the straight jelly mould, run the clay surface with a
wood template cut to fit the clay section, and bear on the side grounds of the moulding piece.
This is termed a " clay template," and forms a uniform sectional clay surface. Then make the case
in the usual way, and get out as many straight casts as will be required. Make another case to the
desired curve. This is done by cutting two " case templates " to the desired curves, one to fit the
upper radius, and the other to fit the lower radius at the springing or ground lines of the cast.
This difference of the radius lengths will be better understood by looking at the section on illus-
tration No. 128, where it will be seen that the back line of the cast at F and F is not perpen-
dicular, or, in other words, the projection of the ground of the cast is greater at the bottom than
the ground at the top, therefore the radius for the latter would be greater than that for the former.
If both edges of the cast sprang from a straight line, one radius would answer for the two
templates. For convex work the radius must be reversed. Having got the case templates cut, they
are then fixed on edge. The distance apart is equal to the width of the straight case. If the
curves of the templates are acute, they should be lathed on the bottom edges, or the ends made up
w ith bricks to form a rough core, so as to obtain a fair thickness for the plaster case. The space
between the templates is filled in with plaster and run with a " bed template." This is cut to the
reverse section of the clay template, and made to bear on the case templates. When the bed and
sides of the case are run, it is then varnished with shellac, and the jelly mould taken out of the
straight case and laid in the circular one. The ends of the case are then made up to the mould with
plaster, thus completing the circular case and mould. If the ends of the jelly mould have acute
points, or are too thin at parts to retain their original forms when laid in the circular case, the
inside ends should be stiffened with plaster. Before the mould is taken out of the straight case,
and after the ends of the circular one is made up to the stiffened ends, the plaster is taken out of
the mould. If stiffening rules are used in the straight mould, they must be made with a series of
saw cuts to allow them to bend to the circular case. They are useful as fixing points for nails to
keep the mould in position when laid in circular cases.

Where there are parts of enrichments that project above the general clay thickness and which
prevent the clay template from passing, the template must be worked close up to the projecting
part and the intermediate spaces ruled off by hand, the projecting parts are then covered with

340 Plastering — Plain and Decorative.

the usual lliickiicss of claj-, and the wliolc cased and moulded in tiie usual way. I'rovision for
the projecting parts must be allowed for when making the circular case. This is done by setting
out the positions of the projecting ])arts on the rough core of the circular case, and then placing
clay blocks on the core where marked. Each block must be larger in dcjjth and width than the
part that it is meant for, and the upper surface of the blocks made in a line with the bed of the
case. After the case is made, the blocks are taken out and the mould laid in. The projecting parts
drop into the cavities made b\- the blocks. The exposed jell\- at the back of the case and the
excess space of the cavities are covered and made up with plaster. If the projecting parts are
deep or the jelly thin, they should be made up with clay or filled in with plaster before the mould
is taken out of the straight case. This enables them to retain their original forms when placed in
the circular case, and while the cavities are being made u\). It will be seen that b\- the whole
processes straight and circular casts of any curve can be produced from the same mould. .Another
way for getting over the difficulty of projecting parts (when the mould is required for circular
work) is done by cutting them off, and then moulding and casting them separatcl)-, and afterwards
fixing them on the main cast. When inaking the model and mould for a front on a circular
balconj-, ha\ing no straight parts, similar to the horse-shoe plan, the plan section for the model
should be taken at the part having the longest curve, and then circular cases made for the others.

Intkrchangeable Moulds. — It is .sometimes desirable to change parts of a mould at will,
especially where minor ]3arts of the main design are only used once, and different designed parts
u.sed for the repeated main design. For instance, the names and dates on the name panels (as
.shown on illustration No. 128) would not be used again, but other notable names, with their
respective birth and death dates, used for each repeated main design. Name panels, with
interlacing strapwork and scroll bands, when amid foliage, fruit, flowers, and figures, form a ])leasing
change and a relief to the eye. The jjanels being enriched with the names of eminent people, with
the dates of their birth and death, are instructive as well as decorative. When \iewed as a whole,
the varied names and busts constitute an appropriate and artistic finish.

Interchangeable moulds are constructed by making a separate mould for each changed part,
and letting it into the main mould, somewhat as in constructing a mould for a fibrous cornice with
"cast enrichments." A bed in the case, and a space in the mould for the changeable part, is
formed before the case is made. This is done by making a plaster "bedding piece" on the model
to the size and form of the proposed changeable part, taking care to allow for a sufficient length
for the longest name in the list, and that is about \ inch thicker than the thickness clay. The
form of a piece is indicated by the dotted line on the " Moore" panel, illustration No. 128. After
the bedding piece is made, the thickness clay is laid in the usual wa\-, laying it close up to the
bedding piece, so that it will have a \ inch projection on all sides above the le\el of the clay.
The case is then made, and when taken off, the bedding piece is taken out, anrl moulded for
future use. The piece is then replaced on the model, and the main mould made. The bedding
piece is next taken out, thus leaving a bed and space for the changeable moulds. The mould
of the bedding piece is filled in, and the cast forms a ground for the modelled work. This is then
moulded, making it a little thinner than the original, to allow for bedding purposes. It is laid in
the main mould, and the whole mould filled in. When the cast is taken out, the thin seam, caused
by the bedded part, is cleaned off The mould of the bedding piece is used in a similar way for
any required number of changed parts. This process is only used where thin casts are required
for special purposes, and as the names and dates may be painted, or still better, modelled with
gesso, or with tow plaster, on the panels when cast, the process will also serve for moulds where

Combined Gelatine and Plaster Moulds.

34'

there are a series of medallions on a repeated main design. The names, medallions, or other
changeable parts ma}- also be made separately, and the casts laid face downwards, and canvased
and brushed with the main cast, as when making fibrous cornices with bedded casts. In fact,
this is the most suitable way for most purposes, as the casts are thin and strong, and have little
or no seams to clean off. Changed parts may also be cast separately and fixed on the main casts,
but special care must be taken when fi.xing the parts, so that the joints will not open when
subjected to the alternate extreme heat and cold that is often found in theatres and halls.

Combined Gelatine and Plaster
Moulds. — A jelly mould in combination with
" plaster pieces " is advantageous for moulding
models having large plain parts, or with deep
sides, or where interchangeable parts are re-
quired. An example of using a plaster piece for
a plain part is shown in " truss moulding." The
methods of formation for the other parts are as
follows. Illustration 133 shows a part elevation
of a panel for theatre proscenium, which is given
as an example for moulding purposes. The
method of moulding is elucidated on illustration
No. 134. This shows a section of the model (a),
which is a section of the panel. It may here
be noted that this panel (and similar models
having strong edges) does not require plaster
" moulding ground," but the original model is
simply made and moulded on the moulding
board M. If a back section to fit anj- construc-
tional work is required, a plaster block, cut to
the section, is fixed at each end of the model
(as shown at P). They form the bearings for
ruling off, thus making the whole into a mould-
ing piece without running a profile or bed.
Taking the length of the panel (when com-
pleted), as being about 12 feet, and the depth
at the sides 5 inches, it will be seen that if
moulded with jelly down to the moulding board,
the sides of the mould, being a pliant body,
and in an upright and partly unsupported posi-
tion, WDulfl incline inwards through force of their

own weight, and consequently cause the sides of the ensuing casts to be more or less wav)-. These
defects are avoided, and the quantity of jell)' reduced (which is a saving in large moulds , bv using
the plaster pieces K and D. Two waj-s of forming these pieces are shown. The upper edge of the
piece B is made abo\e the level of the jelly joint, and sloped to the arris of the model to allow the
mould to draw. The raised ridge forms a corresponding groove in the case, which acts as a joggle
and keeps the piece in position, and prevents it from slipping inwards. The edge of the piece D
is made flush with the arris of the model, and is held in position b\- means of round sunk joggles

Xo. 133.— Fibrous Plaster Panel for Proscexum.

342

Plastcring-

-Plaiii and Decorative.

placed about 9 inches apart. Tlic flush ccIl^o has this advantage, that it allows the jell>- to overlap
the joint, so that if it did shrink a little while the mould was in use for casting, it would still cover
the joint, whereas the raised edge forms a butt joint ; therefore, in the event of the least shrinkage
of the jelly, the fluid plaster, when casting, would run into the open joint, and cause a bad seam
on the arrises of the casts. Similar pieces are made at the ends of the model. Should the long
side pieces break while the mould is in use, the broken parts are laid in the mould, and the joggles
will keep each part in its own place, as with a piece mould, and still be fit for use. Both methods
are used for " plaster piece moulding," but the " flush edge," or joint, is the best. After the plaster
pieces are made, the thickness clay is laid as already described. Another use of stiffening rules
is here shown to illustrate a method for keeping any desired interior part of a jell>' mould straight
and always in one position. This is often desirable in large moulds where there are delicate
mouldings in the design. In the present example they are placed over the inner members of the
panel mouldings, as shown at K and R. They are made about li inches wide and i inch thick, and
in suitable lengths, and are sloped on both edges to allow the case to draw. The>' are bedded
\ inch in the thickness clay, which allows |-inch bed in the jcll\- and in the case. When bedded
in the thickness clay, the exposed part should be shellaced and oiled to prevent their swelling,
and to allow the case to draw freely. After the case is taken off and shellaced and oiled, the

No. 134.— Section of Moulding I'ikce, with Jei.i.v Moulu, Piaster Pii-xes, and Case i'or Proscenium Panel.

rules are laid in the case (but not oiled, so that the jell)- will adhere to them), and temporarily
fastened by means of screws as already described.

The plaster pieces being sufficiently strong in themsehes to keep rigid, it is unnecessar)- to
form the sides of the case (c) all the way down to the board. Any desired depth and thickness
of the sides is obtained by laying a rule close to the plaster pieces as shown at K, and when the
case is finished, the rule leaves a "hand space" for lifting the case off the mould, as shown at H.
Large cases which have to support heavy plaster pieces are strengthened by angle-iron, as shown
at I and I. They are placed about 3 feet apart. Angle irons are also placed in each of the angles
on plan. Wood stays as shown, at s, are placed at intervals to prevent the case collapsing while
being turned over when casting. Cases for large moulds, also plaster pieces, should be made with a
good inward slope, so that the casts can be taken out without turning the case and mould over. Large
casts are more easily taken out of an open mould by using "hand rules," as already described.
The V's are vents. The upper ones are made about i foot apart, and the lower ones 2 feet apart,
taking care that one of each row is made at both ends of the case. The funnels F and F are
placed at the lowest parts at each side of the curved centre, so that the jelly \\\\\ run upwards
in both directions. Their longitudinal position should be in the centre of the mould lengths, so
that the jell\- w ill run equally both ways.

CHAPTER XII.
FIBROUS PLASTER WORK.

Historical— Fibrous Plaster before the Christian Era— Fibrous Plaster Ceilings used in Cairo
IN THE Fourteenth Century- Uses for Fibrous Plaster— Rexovatixc Old Ceilings— Fibrous
Plaster for Panelled Ceilings— Fibrous Plaster Nomenclature— Fibrous Plaster Materials-
Cutting Canvas— Fibrous Plaster Wooden Laths— Fibrous Plaster Casting— Casting Fibrous
Plaster Centre Flowers— Undercutting Fibrous Plaster— Fibrous Plaster Cornices— Mitre
and Joint Stops— Casting Fibrous Plaster Plain Cornices— Casting Fibrous Plaster Enriched
Cornices : Bedded Enrichment System— Moulding and Casting Fibrous Enrichments— Casting
Fibrous Plaster Enriched Cornices : Fixed and Cast Enrichment Systems— Frame Wax and
Gelatine Moulds— Fixing Fibrous Plaster Cornices— Fibrous Plaster Measurements— Fire-
proof Fibrous Plaster— Fibrous Plaster Decorative Sheets— Muslin Plaster Casts— Tow and
Plaster Casts— Rapid Plastering — Fibrous Plaster Slab Moulds- Fibrous Plaster Slab Making
—Setting Fibrous Plaster Slabs— Fireproof, Salamander, Combination, Metallic, External,
Reed, Grooved, Perforated, Finished Face, Gesso, Sgraffitto, Fresco, and Pugging Fibrous
Plaster Slabs— Hardening and Damp-Proofing Fibrous Plaster Slabs— Fixing Finished Face
Slabs— Fibrous Plaster Sign-Boards and Blocks.

Historical. — Fibrous plaster was patented in 1856 by Leonard Alexander Desach)', a French
modeller. The patent was for " producing architectural mouldings, ornaments, and other works of art
formed with surfaces of plaster." The materials named are plaster, glue, oil, wood, wire, and canvas,
or other woven fabric. A part of the .specification reads : " To facilitate the fixing of such moulded
surfaces to other surfaces, wires are, when required, laid into and between the two or more layers of
canvas. Flat surfaces are strengthened with canvas, wires, hooks, or pieces of wood ma\- be
inserted whilst the plaster is in a fluid state." The specification also includes the formation of
solid slabs of plaster strengthened with two layers of canvas in the centre. Desachy introduced
the manufacture of fibrous plaster decorations into London, where he employed a large number of
hands, male and female. The late Owen Jones, architect, and the author of " The Grammar of
Ornament," was the first patron of fibrous plaster. Desach}-, after a precarious run of work, returned
to Paris. The business was then for a time carried on under the management of J. M'Donald
and R. Hanwell, respectively foreman and modeller to Desachy. When Desachy retired from the
business, he was pecuniarily indebted to Owen Jones, which handicapped the efforts of M'Donald,
and the business was eventually taken over by Messrs G. Jackson & Sons, London, who acquired
the then existing patents. They have introduced many improvements, and brought it to a high
degree of perfection. During the construction of the old Oxford Music Hall, about a generation
ago, they successfully defended their patent rights. Fibrous plaster during the last two decades
has been worked by other firms, and it is now open to all plasterers. Such is the British history
of fibrous plaster. It is an old saying, that "there is nothing new under the sun." This ma\- be
safel)' applied to fibrous plaster, as the u.se of linen and canvas, in conjunction with plaster and
glue, was known and practised by the Egyptians long before the Christian era. From ancient
MSS. still extant, and ancient coffins and mummies, now to be seen in the British Mu.seum, it is

344 Plastering — Plain and Decorative.

conclusivcl)- proNcd that linen, stilTcnecl w ith plaster, was used for decorating coffins, and when
embalming human bodies by the Egyptians, 1500 H.C. Dr Petrie's discoveries at Kahiin go even
further, for he fouml that plaster and canvas were used for casting mummers' masks nearly 4,400
)-ears ago. Plaster, canvas, glue, and wood were used in the formation and decorations of ceilings
in Cairo eight hundred years ago.* According to the MS. of Cennino Ccnnini, who wrote in
1437, fine linen, soaked in glue and plaster, was used for forming grounds on wood intended to be
painted on.t Thus it will be seen that plaster combined with linen has an ancient as well as a
modern historj-. Plaster mixed with tow was used for the decorations of a church in Hamburg
about two hundred jears ago. While giving Desachy the honour of reviving the process, and of
introducing it into England, it is more than probable that he got the idea from some of the
French writers — Reinaud, Prisse D'Avenncs, Girault dc Prangey, or others, who had very fully
described and illustrated ICg\ptian arts and architecture. Coming nearer home, it will be found
that canvas has been used for ages for another jjlastic purpose. Canvas and mortar were in cvery-
daj- use in Great Britain up to the middle of the present centurj- as a heat-resisting plaster. It
is still to a small extent emplo}-ed in some districts, but its general use ceased after the introduc-
tion of Portland cement. Canvas was used as a binding power to pre\ent the mortar round wash-
house coppers from cracking or expanding when subjected to heat. The mortar was composed of
equal parts of haired lime and gritty road scrapings. Sometimes clay was substituted for the
scrapings, but more often all the three stuffs were well worked together. The walls of the copjjer
were rendered with this mortar, and allowed to stand until the next da)-. Then it was floated with
the same kind of stuff, and while soft, a sheet of strong coarse canvas was laid over the mortar,
and pressed and patted with a hand-float into the mortar, and then trowelled. I have found that
this canvas plaster, after man)- )-ears' wear and exposure to heat and damp, was extremel)- hard and
tenacious when being pulled down for alterations.

UsE.s FOR FiBKOL'S Pl.ASTER. — Plbrous plaster is an important branch of the plasterer's
craft, and is now in great request b)- architects, builders, and decorators. Its uses are .so
various that it is becoming very general for works requiring lightness and raj)idit\-. It is fast
superseding carton-[)ierrc and papier-mache. It is not only lighter and tougher than either, but
it also can be made in larger sections, and adapted to more purposes. P'ibrous plaster was used
in the Paris Exhibition of 1878 for the construction of the ceilings in the principal edifice of
the Exhibition. Some of the panels were ncarl)- 40 feet square. The panels, with the enrich-
ments, were composed of fibrous plaster, but tow was used instead of canvas or trellis cloth.
In France it is known b)' the name of " staff" and the enrichments in their frames as c/inssis-en-
stnff. The " Street of Nations," as well as the large arches in the permanent buildings of the
Exhibition, were composed of this material. In the South Kensington Mu.seum there is a large
figure of Moses, taken from the marble original in the Church of San Pietro in Vincoli, Rome,
executed 1541-53, by Michael Angelo. The cast was made by the Desachy process, and weighs
onl\- 168 lbs. The ornamental plaster work of the new Opera Hou.se in Paris has been made in
staj^. Hbrous plaster affords great facilities for the faithful reproduction of ancient or modern
architectural or other works, either for temporar)- or permanent purposes. I ha\e used it for stage
properties, notabl)- for the column capitals in the Ducal Palace scene, when Miss Marie Wilton
l^roduced " The Merchant of \'enice " at the old Prince of Wales' Theatre. The caps for per-
spective purposes ranged from 3 feet to 4 feet 6 inches in height. The bells and the abacus
and necking mouldings w-erc composed of fibrous plaster, and the enrichments modelled in plaster
* See Saracenic Plaster Work, Chapter X\'I. -t See Fresco, Chapter VII.

Uses for Fibrous Plaster. 345

and tow. I used a similar process for scenic properties for the late C. Rice at the Royal Theatre,
Bradford. I used a combination of tow and canvas fibrous plaster (with iron wire instead of
wood laths) for the ornamental parts of various built scenes ; also a fountain and other projjerties
for Mr H. E. Abbey, when Miss Mary Anderson appeared as "Juliet," in 1884, at the Lyceum, London.
Fibrous plaster has been successfully adapted for construction and decoration. I used this material
for constructing facsimiles of the temples of Saturn and Vespasian that stood near the Roman
Forum in the grounds of the Italian E.Khibition, London, 1888. The temple of Saturn, with its
eight remaining columns and the entablature, was 33 feet high. The temple of Vespasian, with its
three remaining columns and cornice, was 38 feet high. They were constructed from measured
drawings by Mr T. W. Cutler, architect. After standing in the open air during the si.x months that
the Exhibition was open, they were taken down, seemingly none the worse for the exposure, and
were then sent "on tour" for other exhibitions. I al.so used plaster and tow for modelling the Italian
coat of arms, and a replica of the old Roman shield for the P'ine Art Galleries. The whole was made
in the shop, and then fixed in position under the superintendence of my then partner, Mr G. M. Jay.
It has often been used for triumphal arches in streets for public rejoicings. The decorations and
guns of the old " Victory," for the Naval Exhibition, 1891, were faithfully reproduced in this material
by G. Jackson & Sons. Ten thousand superficial yards of fibrous plaster were supplied by the
Plastic Decoration Company in the reproduction of ancient streets for "Venice in London." The
Veronese Company and Marshall & Slade made many thousand yards of ornamental fibrous plaster
work for the Indian and other exhibitions at Earl's Court, London. No less than 150,000 superficial
yards of fibrous plaster were used in the buildings at the " World's Fair," Chicago.

Besides those more or less temporary purpo.ses, it is extensively used in the decorations of
man)- classes of permanent building, and is sent abroad in large quantities to our own colonies
and other countries. Messrs G. Jackson & Sons, the Plastic Decoration Company, C. H.
Mabe\-, and J. Bickley, of London ; Cordingley, Greenwood, and Home, of Yorkshire ; Rule, of
Sunderland ; and T. Jones, of Liverpool, all employ a large staff" of skilled workmen in the
manufacture of fibrous plaster. Mr A. M'Gilvray, of Glasgow, executed a vast quantity of elabo-
rate fibrous plaster ceilings and other works for the Gla.sgow Municipal Buildings. Nearly the
whole of the numerous theatres and music-halls which have been built in London and the provinces
during the last generation have been decorated with fibrous plaster. This material has also been
used for the decorations of ships' saloons, being first introduced into the " City of New York " and
her si.ster s.s. the "City of Paris" by Mr G. T. Robinson, in 1887, and shortly after into the
" Majestic " and " Teutonic," after which its use has become common, its lightness and elasticity
rendering it very applicable to ship decorations. One of the most striking examples of the utility
of fibrous plaster was the buildings erected on the Champ de Mars for the Paris Exhibition in 1889.
The Indian Palace, one of the most imposing edifices in the Exhibition, was the only one that was
mainly done by English plasterers, and was erected by Messrs Joubcrt. of King's Road, Chelsea.
London. Messrs Joubert found it more profitable to pay English plasterers lod. per hour, with
lodgings and expenses, than to pay Frenchmen 8d. per hour, with no lodgings or expenses. The
Palace was about 180 feet in length and 50 feet in width. It was surmounted by a large central
dome and fourteen smaller ones, with minarets and towers. It was constructed of wood framework
bolted together, and the walls, ceilings, and domes lined with fibrous plaster, solid plaster being
emploN'ed where necessary. The exterior was also formed with fibrous plaster. All the decorations
were taken from original scul|)tures in the Indian Museum at South Ken.sington. The building was
designed by Mr C. Purdon Clarke, CLE.

346 Plastering — Plain and Decorative.

For centre flowers or other surface decorations, this materia! is particularly suited. Its great
lightness is a decided point in its favour, as it does not tend to pull down the lalh and plaster,
but when properly screwed up into the joists, or even the laths, it becomes a support to the three-
coat piaster ceiling. An ordinary-sized centre flower can be securely fi.xed with eight or twelve
screws, and without disturbing the lime-plastered ceiling, thus avoiding damp, dust, or dirt, as
generally caused when fixing solid plaster centre flowers, which require the ceiling to be cut for
keying purposes. A well-made fibrous centre flower, 2 feet in diameter, only weighs about 4 lbs.
Therefore it would no\v be possible to .send a centre flower by parcels post !

Rexovatixc; Old Ckilinos. — Where old or cracked ceilings require renovatidns, fibrous
plaster is admirably adapted. Old ceilings, whether plain, ornamental, or panelled, can be re-covered
without taking down the old plaster. A measured plan of the ceiling is accurately taken, al.so
the projections and profile of the main cornice and ceiling, or beam mouldings, as the case may be.
From the.se measurements and profiles, a new design, or the old one, is arranged to cover the old
mouldings and ceiling surface, using the old work as a working ba.se and fixing points. The old
work should be probed in places with a fine bradawl, to ascertain the positions of the joists and
cornice brackets. These positions are marked on the drawings and corresponding laths, for fi.xing
purpo.ses, and are laid in the new work while being made. The work is made in suitable sized
sections, with the joints at the strongest and least noticeable parts. The design can, in many
cases, be so arranged that the joints are covered with small mouldings, and screw holes with
paterse. Joints can also be made in the centre of the bed of enrichments, which is afterwards
covered with the enrichment. Fibrous plaster enrichments being made in lengths, and fixed dry
with fine nails, there is no damp or dust. The abo\e precautions for the joints are especially
requisite for work that has to be painted before being fixed. The joints in ordinary work can be
stopped with gauged plaster or Parian cement in the usual wa\-. The work is made in the plasterer's
workshop, and when dry, it is screwed on to the old plaster work without disturbing the contents of
the room, or causing damp or dirt. The ceilings can also be painted and gilded before being fixed,
if required.

Fibrous Plaster for Panelled Ceilings. — Fibrous plaster is now largely used for

panelled ceilings. Elaborate ceilings with mouldings and enrichments are cast in large sections,
and screwed on the joists, thus dispensing with the ordinar)- lath and plaster. " Finished face
slabs " are also used in a similar way, and the joints covered with fibrous mouldings or ribs, forming
a plain panelled ceiling at a small cost. This method may also be used for covering and enriching
plain or old ceilings without disturbing the existing lath and plaster. Fibrous plaster is now
extensivel}- used for casing wood or iron beams and girders ; the casing, plain or enriched, can be
made the entire length of the beams, thus avoiding joints. Fibrous plaster is also used in a similar
waj- for casing columns and pilasters. Columns are made in two \ertical halves, and screwed
together over the iron or brick core, and then the joints are stopped.

It will be seen that fibrous plaster can be adopted for many purposes, and that its uses are
unlimited for plain and decorative plastic work. It is also a good and ready substitute for wood
casing, and decorating rough or constructional surfaces. Fibrous plaster being made in the shop,
and dried before being fixed in the building, the work is not delayed by frost or inclement weather.
This is a decided advantage where time is a principal consideration. Fibrous plaster will never
entirely supplant the old-fashioned lath and plaster (or "solid work," as it is termed in the trade),
but its utility for many purposes and places is fully demonstrated by the fact that its employ-
ment is rapidly increasing, and that it is now specified by many of the leading architects

I£J

Materials for Fibrous Plaster. 347

for plastic decorations in palaces, mansions, clubs, and other buildings throughout the three

kingdoms.

From some cause or other, probably the apathy or inability of London master plasterers, and
the slight encouragement given by them to apprentices and modellers, many extensive works in
fibrous plaster have been secured by car\ers (notably Gilbert Scale, a London modeller and
carver), who can interpret by their read>- pencils the distinctive character of ever>- style, and furnish
architects with appropriate and clever decorative designs. Some of the leading specialists in plaster
decoration — Jackson & Son and Mabey of London, M'Gilvray and Ferris of Glasgow, and others,
have, however, somewhat turned the tables on these outside rivals in the trade by executing the
finest artistic work, not only in plaster, but in stone, wood, and metal. Several of the principal
London builders, Cubitt, Bywater, TroUope & Sons, Higgs & Hill, &c., also decorators and art
furnishers. Waring & Gillow, F. De Jong & Co., Maple & Co., V. & G. Jelley, Barker & Co. of
London, Marsh, Jones, & Cribb of Leeds, and others, manufacture their own fibrous plaster work.
It is the bounden duty of all classes of plasterers to encourage the apprentices in the study and
practice of designing and modelling, because it is safe to prophesy a great future for decorative
fibrous plaster work.

Fibrous Plaster Nomenclature. — In consequence of fibrous plaster work and its offspring
" reverse-moulding " being comparatively new branches of the plasterer's craft, and not being in
general use, a great want of regular terms has arisen. This neglect is partlj- owing to the
carelessness or indifference of those whose interest ceases with the close of the day, and partly
to others whose interests are concerned in keeping the process for their own particular use. Some
of the existing terms are confusing, and are apt to be mistaken for those used in the more familiar
branches of the trade. It is therefore imperati\e for perspicuity in this description, and for future
reference and identification, that each part and process should be definitely named. Existing
names that are not conflicting will be retained. Terms for unnamed parts, and new names for
old ones, will be given with due regard to applicability and brevity. These will be readily under-
stood b)- the present proficient workers in fibrous plaster.

Fibrous Plaster Materials. — The materials for general fibrous plaster work are plaster,
canvas, size, and wood laths. Wire netting, galvanised iron wire, tow, fibre, sawdust, reeds, slag-wool,
wood-wool, Portland cement, slag, coke-breeze, and other aggregates are used for special purposes.
These are described under their respective headings. Plaster for this work should be strong and
slow setting. Coarse plaster, if strong and not sandy, may be used for some purpo.ses, such as
making up edges, also for parts of " fibro slabs." Canvas for fibrous plaster should be strong,
coarse, and open-meshed. It should be strong to resist strains and pressure ; coarse, so that the
plaster will adhere to it ; and open, so that the jslaster will go freely through the meshes when
brushed. The size of the mesh varies from A inch to ^ inch, according to the class of work in
hand, the small mesh being used for fine or small casts, and the larger mesh for general work.
A still coarser and more open kind is used for some kinds of fibro slabs. Canvas for fibrous
plaster is generally supplied in the No. 3 quality, and in 52 and 72 inch widths. Canvas is also
known by the name of " scrim," and is principallj- made in Dundee, from speciall\- prepared yarns,
to resist the process of decay. The nature of the fibre from which the >-arns are made necessitates
careful treatment in the preparation previous to spinning. It is chiefly supplied by A. F. Latto &
Co., London.

Cutting Canvas.— There is quite a knack in cutting canvas. Cutting by scissors is a
slow method. It should be unrolled and doubled flat in as man\- plies as can be conveniently

348

Plastering — Plain and Decorative.

cut at one draw with a knife. Some men can cut twelve plies at once. It is generally cut on a
soft wood board, but it is cleaner cut on a piece of plate-glass which has previously been bedded
with plaster in a wood frame. The knife cuts best when .sharpened on a rough sandstone. This
gives a slight rough or tocjthed edge, which divides canvas better than a .^^mooth edge. As much
canvas should be cut at once as will last for one or more days.

FlUROU.s Plaster Laths. — These are generally cut from second pine, red-wood, or any old
wood not liable to twist or warp. Laths are cut in various lengths and thicknesses, according
to size and weight of the work in hand, and are left rough from the saw. To save time and
confusion, the various kinds are named and described as required for the various works. Laths are
used for strengthening the work, also for fixing purposes.

Size Water. — Size water should be clean to ensure strength, and it is best when made with
good glue and clean water. It should be tested by measuring a given quantity with a given
quantity of clean water, and then gauging a small amount of plaster to determine whether it sets

No. 135. — Fig. i. — Panel Mould showing Process of Filling in a F'tbrous Plaster Cast.
Fig. 2. — Portion of Mould with Cast nearly Finished.

too quick or too slow. Suitable measures should be kept ready for measuring both waters. Cream
of tartar is also used to retard the setting of plaster.

Fibrous Plaster Casting. — The process of casting fibrous plaster work, although simple,
requires care and method in manipulation. Attention must be given to the gauging of the plaster,
and the time of setting noted. Never begin gauging until all the necessary canvas and laths are
cut to the required sizes. Where there are different sizes, place each in a separate place to save
time and confusion. Put away the cut canvas in a handy place where it will be free from dust
and plaster splashes. Always cut more of each kind than is actually required for a day's work, to
allow for any unforeseen accidents. The size water shoukl be tested and timed. The annexed
sketch (No. 135, Fig. l) shows the mould of a plain panel with the laths and a part of the canvas
in position. The panel is 3 feet long, 1 foot wide, and i inch thick, with a plain band 2 inches wide
and curved to the centre surface. M and M are the top and side of the rim of the mould. The
mould's rims are the ruling-off edges. The f's are the side and end laths, which are \\ inches
wide and \ inch thick. The side laths are 2 feet i li inches long, and the end laths 8^ inches long.
This allows for a \ inch space at each side and end for plaster and canvas. The canvas is cut into
sheets 3 feet 8 inches long and i foot 8 inches wide, which allows for a margin 4 inches wide at
the sides and ends to be turned back over the laths and on to the surface, as shown by a portion
at C. This margin when turned over strains a part of the surface canvas and binds the laths
together. Two sheets of canvas are used for good work. It sometimes happens that the outside
thickness of the cast is too thin to allow of two sheets to be turned over. In this case the second

Casting in Fibrous Plaster. 349

sheet is cut to the size of the cast, with just a sufficient mar«,rin to cover the outer sides of the laths.
Care must be taken to so cut the canvas at the external angles that it can be laid flat without
increasing the thickness at the angles. This extra overlapping may be avoided by cutting a piece
equal in size to the margin out of each angle, as shown at A. The small square pieces that are cut
out of the angles are useful for covering lath joints and a variety of other jMirposes. If space
permits, the angles of the canvas may be cut diagonall>' as shown at li. The first lot of canvas and
laths should be tried temporaril_\- in the moulfl to test their sizes and po.sition.s. The mould is then
oiled, and as much plaster gauged— but without size water— as will cover the surface of the mould
barely \ inch thick. This gauge is called " firsts," and is brushed over the mould to expel the air.
The next coat is called " seconds," and is gauged with size water to give time to lay and brush the
canvas before the plaster sets. The two gauges should be done at one time, .so that the " firsts "
will not be set before the "seconds" can be applied. When the "firsts" is slightly firm, or "tacky," a
small portion of " seconds " is poured on, and lightly brushed over the " firsts," so as to bind the
two coats together, but without disturbing the thickness of the " firsts." For delicate work, the
"seconds" is gently splashed on with a tool brush. This tends to bind the two coats with less
brushing.

Great care must be taken that the " firsts " is not set before the " seconds " is put on and
brushed ; also that the " seconds " is not set when the first sheet of canvas is jjut on. This is one
of the secrets of success in casting fibrous plaster, becau.se if the two coats of plaster are not
properK- incorporated, the " firsts " will be left in the mould, and if the canvas is not properly
worked and brushed into the " seconds," both will be left in the mould, and the cast will be useless.
Having laid and brushed the two coats, the first sheet of canvas is laid (allowing the margin to lie
over the rim of the mould), pressing it down into the angles at the sides and ends, also into sunk
parts of the mould with the fingers, beginning in the middle of the canvas piece, so as to work out
the air and prevent creases. Then using the fingers of the left hand for pressing the canvas more
accurately into the hollows, take in the right hand a gauge brush and dip it into the gauge-pot
containing the " seconds," and brush all over the canvas until the surface plaster and the canvas is
well knit together. The second sheet is now laid in a similar way, care being taken that the first
is in a moist state. If dry, brush it over with "seconds" to give a better binding key for the new
sheet. It may here be noted that if the size or shape of the mould necessitates several pieces of
canvas to cover the surfiice, each piece should be laid to lap about 2 inches over the joints of the
previous one, and the joints of the second coat of canvas should be made in the same way, and at
the centre of the first coat pieces. This method of lapping and breaking the joints makes the cast
stronger, thinner, and more uniform. It will be understood that the canvas margin that lies on the
mould rim is left unbrushccl with plaster until the laths are laid. The laths are dipped in or
brushed over with " seconds," and laid in position, the bed of each being previoush- brushed with
".seconds" to give a solid bed. The canvas margin is now turned back o\er the laths, following the
form of the lath, and then well pressed and brushed into all angles. Turn over one side and sheet
at a time, and fold the external angles closel)' together. When all the margins are finished, stiffen
a little "seconds" with dry plaster, and make up the edge of the cast until flush with the mould
rim, as shown at R (Fig. 2). These edges are made from \ inch to 1 inch wide, and ruled fair with
the mould rims, so as to leave a smooth edge and a true bearing for fixing purpo.ses. Casts \\ ith
extra thick edges or rims are strengthened b>- placing the rim laths on edge, or by using two
thicknesses of laths and canvasing and brushing. Thick edges are also made up with .strips of
canvas dipped in plaster and brushed in position. A strong way is to make the edges up with tow

350 Plastering — Plain and Decorative.

and plaster. Care should be taken that all canvas margins are turned back over the rim latlis or
on itself to strengthen the edge before the plaster sets, because if set, the canvas cannot be turned
over so freely or made to fit so close to the laths or angles. It is also apt to lift the plaster from
the face of the mould. It sometimes happens that the canvas and plaster get above the level of the
rim. In this case it can be cut down flush with the rim with a sharp knife after the stuff is set.

I"ig. 2 shows a portion of the mould and .sections of the cast, side laths, and made-up sides or
rim of the cast. I! is a " bod)- lath" with a portion of a can\-as stri|3 unbrushcd. Bod)' laths are
used to strengthen large casts. Canvas strips should be cut sufficiently wide to cover the laths and
about 2 inches on each side. When filling in large casts, there may be more than one gauge of
" seconds " required. A small part of each gauge should be put aside as a guide to know when the
under coats are set, becau.se the cast must not be taken out till all is set. If the setting is properly
timed by the size water, this precaution is unnccessar)-. P'ibrous casts being strong and fle.\ible,
and containing a small body thickness of plaster, there is little or no expansion, therefore the casts
are much more easily relea.sed from the mould than " solid " casts. The terms " brush " or " to
brush" means to brush the laths or can\-as with "seconds." It is then termed " brushed." The
making of all classes of fibrous plaster is based on the foregoing method, but as a further aid to the
novice, the method of making ornamental works in fibrous plaster is given hereafter.

To Cast a Fibrous Plaster Centrk Flower. — The anne.ved sketch (No. 136) elucidates
the method of casting a fibrous centre flower in a wax mould. This centre flower is 3 feet in
diameter. A portion of the plan, with section, is shown in Fig. i. Take this section to distinguish
the various parts of the centre flower. .\ is the body, 15 the border, C the centre, and I) the seed, or
drop. In the old way for "solid work" the border is cast separately in short lengths, but for fibrous
work the whole of the border is cast with the bod)-. It will be seen that the centre is cast
separately. A bed, as shown on the section, is made on the body to act as a fixing point for the
centre. This method saves a considerable quantity of wax when moulding, especially if the centre
has a deep projection. It also gives greater freedom for handling the original when moulding, and
the mould and cast when casting. The seed is also moulded seijarately for two reasons — first,
becau.se it is often dispensed with when a metal rose is used with the gasfittings ; and second, to
allow the centre to be moulded in one piece.

Fig. 2 shows a portion of the wax mould of the body with a |)ortion of the canvas, and plaster
and laths in position. I and i) are the inner and outer rims of the mould. E and F are the inner
and outer rim laths respectivcl)-. The rim laths arc I J inches wide, \ inch thick, and as long as
can be cut out of a deal board. The outside radius should be \ inch less than the mould rims, to
allow a space for the plaster and the canvas to be turned up and over the laths. There must be
sufficient rim laths cut to complete the circles, also extra pieces to overlajj or break the joints if
required. The joints need not butt accurately, any little inequality being made u]) with plaster and
canvas, or, if space permits, covered with overlapping pieces. Splay joints, as shown at F, are
stronger than square ones. R is the plan of a rib lath. Four are used and placed at right angles to
each other. Large flowers, or those with deep sections, require six, eight, and even ten ribs to
strengthen them. The ribs for this size of flower are % inch thick, but ribs up to i inch are used
for larger ones. Ribs \ inch thick are used for smaller and thinner flowers than the above. The
outer rim lath for this one is cut to a radius that will give the most depth, to allow the ribs and the
"point laths" to overlap. Should the depth not allow the laths to overlap, they are cut to fit
between the rim lath and the rim of the moulding, as shown by the two laths at G. These two
" point laths " strengthen the outer edges, also the points of the cast. Where space permits, " point

Casting Centre Flowers in Fibrous Plaster.

35'

laths " may be used to lay over or under the rim laths, as shown at P and V. The latter way will
be found useful for strengthening narrow or long points in a cast.

Fig. 3 shows the section of one-half of the mould, s R is the section of the rib laths ; S E, S F,
and S P are the sections of the inner and outer rim laths and the point laths respectively. The
canvas should be cut in eight radiating pieces, allowing for a 2-inch overlap at each side, and a
4-inch margin be\-ond the outer and inner rim laths. A quantity of short pieces of canvas are
required to fit the border, as shown at H. The border pieces are cut to take the general outline of
the border. It is not necessary that the pieces should be cut accurately to fit all the curves. If the
edges are deep, leave a margin to be turned over; and if thick, turn over straggling edges, making up
any little parts with small pieces of canvas. Galvani.sed iron wire, bent to the contour of the outer
line of the cast, is sometimes used to strengthen thin or tender parts of casts. Having cut sufficient
laths and canvas, and oiled and washed the mould out, the " firsts " is gauged and carefully brushed
into all the sunk parts, and then the " seconds " brushed or splashed as before. The border pieces

No.

?6.— Casting a Fuirous Plaster Centre Flower.

Fig. I. -Part Plan, with Section of Centre Flower. Fig. 2.— Part of Wax Mould with Cast partly filled in.— Fig. 3. Section of
Body Mould and Cast. Fig. 4— Half Plan and Section of Centre. Fig. 5.— Section of Centre Mould and Cast.
Fig. 6.— Half Plan and Section of Seed Mould.

of canvas are laid first, brushed and pressed into the angles of the outline of the border, making up
an>- uncovered parts with small pieces. This is repeated until the whole circle of the border is
completed. The radiating pieces for the body are next laid, putting down one at a time, and so as
to overlap each other, leaving the margin at the inner rim and the margin outside the line of the
outer rim laths unbrushed. After all those pieces are laid and brushed, the outer and inner rim
laths are laid in position, taking care to brush them and their beds as before. The margins are
next turned over and brushed. The four rib laths are next laid, and covered with canvas strips,
and brushed. The point laths are next laid, canvased, and brushed, and then the outer rim made
up and ruled off flush x\ith the outer rim. Plaster and canvas, or tow dots are formed on the inner
top edges of the rib laths (as shown at T\ and ruled fltLsh « ith the outer mould rim. These dots
prevent the cast from drooping hi the centre while drj-itig, and also form resisting points, to keep
the centre of flower true when being screwed up. Should the overlapping of the rad.atmg pieces
and the small pieces of canvas, which are sometimes used for filling in extra deep parts m the

352 Plastering- Plain ami Decorative.

mould, not complete two coats of canvas, the deficiencies arc made up with small pieces, and
brushed. The whole surface is then brushed with " seconds," to bind all margins, and give the
whole surface a more finished appearance. The mould is now placed in warm water until it
becomes warm and pliable, when it is taken out and eased round the rim, and the cast gently pulled
out. When using large wax moulds which cannot be conveniently put in a hot-water tank, they
may be made pliable by pouring hot water over the back of the cast, also by using hot-water cloths
made of old sacks or canvas.

Fig. 4 shows an enlarged plan of one-half of wa.x mould for the centre, with a part of the
plaster, canvas, and laths in position. I and O are the inner and outer mould rims respectively.
E and F are the inner and outer rim laths. The K's show the plan of three of the four rib laths.
.s C is the section of the cast.

Fig. 5 shows a section of one-half of the mould. L is one of four legs which are placed at
equal distances apart in the liquid wa.v, and flush with the top. When the wax is firm on the top
surface of the mould, it is " bled " b\- cutting a hole in the side, and allowing the interior licjuid wa.x
to run out into the wax-pot, then pressing the top skin down, thus leaving the mould nearly
uniform in thickness, and the legs as supports to carry the outer rim. This allows for the wa.x
which has run out to be used for other purposes. The mould is also more pliable than if solid.
The section of the inner and outer laths will be seen under .S K, which is the section of the rib laths.
The dotted line indicates the outline of the perforated flutes. The first coat of canvas for this
mould is cut in four radiating pieces, with margins as shown over the inner and outer mould rims.
The second coat is cut to the same size, if space permits, for the second thickness of margin ; but if
the cast is thin at the outer edge, then the second coat is cut to fit the surface of the mould at
the outside. It will be understood that a margin is left for the inner rim, where the thickness of
the cast is not confined to any particular measure. The canvas is laid as before, breaking the
joints, and covering all the surface, including the perforated flutes. The rim laths are laid, and
then the margins are turned over and brushed. The four ribs are next placed in position and
brushed, and the rim made up and ruled off as before. When the cast is set, the canvas and
plaster which covers the perforated flutes are cut off flush with the wax, and ragged edges made
smooth by brushing. When making originals for perforated work, the sinking should only be
about \ inch deep. If deeper than this, the edges at the perforations of the cast stand up from the
surface line, and are more liable to get broken or bent. Where the perforations are large, it is
usual to lay and brush canvas strips around, and flush with the projecting parts in the mould which
form the perforations.

Fig. 6, shows a plan of one-half of the seed mould. I and o are the inner and outer rims
respectively. The inner rim forms the hole for the gas-pipe, .s D is the section of the cast. M is
the section of the mould. This mould has two parts (a front and back), with the joint at K. As this
is too small to admit of laths, canvas, or, better still, tow soaked in plaster, will make the cast
sufficiently strong. The inner outline of the cast is denoted by a dotted line. This lca\-es a
shouldered part at the top, which forms a key for fi.xing on to the centre. The seed is best fixed
with tow and plaster. If there are any plantings to fix, trimming or stopping required, it should be
done while the casts are green. Centre flowers or other flat work while surface drying should be
laid flat to prevent them from twisting. \^'hen the external dampness has gone off the cast's
surface, it is usual to lay them in an oven or a drying-room to accelerate the drying. Canvas
sometimes shows on surface parts of new casts. These canvas patches (if not too rough) will dry
out, and will be scarcely perceptible when the cast is dry. Canvas patches are caused by the

Plain Cornices in Fibrous Plaster. 353

" firstings " being unequal in thickness, also by soft gauging. Mouldings, or other parts that require
smoothing, are rubbed with fine glass paper after the casts are dry.

Undercutting Fibrous Plaster.— It is often desirable to undercut some parts, such as
fruit, flowers, and foliage, which have been stopped down on the original to allow a wa.x mould to
draw, and as fibrous plaster is thin, and difficult to cut clean, it is necessary to make a provision for
this. This is done by first stiffening a portion of ".seconds" with dry plaster, and then working it
with a small tool round the proposed undercut parts in the mould, and before this is set the mould
is filled in as before. If the undercut parts in the original are large, it is best to make plaster
pieces at the parts before the mould is made. The small seams caused by the joints at the plaster
pieces are easily taken off with a small tool or a fine file. Undercutting by hand is the best way
for small parts. The work is more varied and artistic in appearance when done by hand.

Fibrous Plaster Cornices.— Mouldings of any reasonable length may be made in fibrous
plaster, but they are general!)' made in lo to i8 feet lengths, or in such sizes that two or three casts
will make up the length of an ordinary-sized room. For example, if a room is 33 feet by 20 feet,
the mould would be made 13 feet long, out of which would be cast three 1 1 -feet pieces to make up
the full lengths of one side, and two lo-feet lengths for one end of the room, the other side and end
being made up the same way. Short pieces for breaks or other parts arc cast out of the same
mould. The mould is made longer than the longest cast required, to allow for a bed for the " mitre
stops " that are used for forming internal and external mitres, and also for square butt joints on the
casts, hence the reason for the above mould being 13 feet. The extra length of mould is regulated
by the projection of the cornice. Fibrous plaster cornices are often cast in "reverse moulds." This
useful part of plastic art should be mastered before attempting the casting of fibrous plaster work.
A quick way of producing fibrous plaster enriched cornices is by the use of jelly moulds. A
moulding-piece is first made by running a length of moulding on a bench, then fi.xing the enrich-
ments, keeping both ends jointed. The model is then cased, moulded, and the casts made.

Mitre and Joint Stops. — Mitre stops being required before the cornice cast is made, the
method of making them is given first. Mitre stops are made of plaster, and are u.sed as fences to
form mitres and joints in cornices, &c. They are laid on the casting mould, and being movable,
any desired length of cornice (less than the length of the mould) can be made, and each length with
any desired form of mitre or joint at both ends of the cast.

Fig. 2, in illustration No. 137, elucidates the method of making mitre and .square joint stops.
This also shows the section of a re\-erse casting mould for a plain cornice, having a projection
about 7i inches and a depth of ji inches, with sections of the laths u.sed for the cornice cast. L H E
is a left-hand external mitre stop ; L H I is a left-hand internal mitre stop ; and S is a square joint
or butt stop. The right-hand mitres are, of course, cut to the opposite angles. Mitre stops are
made by first covering a sufficient length of the casting mould with damp paper, laid to the contour
of the mouldings. The paper allows the plaster piece to leave the mould freely, and prevents
chipping. Gauged plaster is then laid on the papered surfiice to the desired thickness, and ruled
square with the mould rims. If wood rules are laid flat on the rims to act as fences, no ruling off is
required. The plaster (for small mouldings) is made up to the square of the rim lines, so that the
mitre stops will act as ruling-off bearings, or points for proving the square of the cast when being
filled in. When mitre stops are not made up to the square, boards cut to the square are fixed at the
mitre stops as guides for testing the squareness of the casts. This is only necessary where the space
between the mould's surface and the square of the rims will onl>- admit of the laths and a sufficient
thickness of plaster and canvas, which makes up the cast nearlj- to the square of the rims, as shown

354

P/asteriiig — P/aiii and Decorative.

by the sections and the dotted lines in Figs. 3, 4, and 5. Where there is ample space, and the laths
well within the square, as shown in Fig. 2, a thickness from 2 to 3 inches will give sufficient strength
for the stops and width of bearing for ruling off or testing the .square of the cast. After the plaster
piece is taken off, the various lengths of the stops are set out and sawn to the required angles. The
mitres are best sawn in a mitre bo.x. Each stop should be lettered, to save confusion. All measure-
ments for stops and cornices should be taken from the wall line. If the cornice is large, or has acute
angles, or is difficult to draw in places, the stops must be made in two or more longitudinal sections.
C.\STIXG FiBROU.S Pl.\ster Pl.\in CORNICES. — Illustration No. 137 also elucidates the
method of casting plain cornices having various profiles. Fig. i shows a reverse casting mould (in
plaster) on a running board, w ith the plaster, canvas, and laths in position. This cornice has a
ceiling projection of 12 inches, and a wall depth of loi inches. RB is the running board or bench ;
•S is the .section of the casting mould, the dotted part being the plaster ; C R is the "ceiling rim " ;

No. 137. — Casting Fibrous Plaster Plain Corniges.

and w R is the " wall rim " of the mould. These rims are also known as the " striking-ofif edges " of
the mould. They represent the ceiling and wall lines. No laths, canvas, or plaster must protrude
beyond the square of these lines. The square of the ceiling and wall lines is indicated by the dotted
lines on Figs. 2, 3, 4, and 5. The ceiling and wall lines are horizontal and perpendicular respectively.
F P is the first coat of plaster and canvas brushed together. The unbrushed canvas margin lies over
the mould rims and on the board, ready to be turned over when the ceiling and wall laths are laid
in position. The various laths, before being canvased and brushed, are also shown in position. C is
the " ceiling lath " ; w is the " wall lath " ; and B is a " body lath." The ceiling and wall laths are
about 2 inches wide, \ inch thick, and in lengths according to the cast. Thicker and wider laths are
required for larger cornices. The body lath is about 2 inches wide, and f inch thick. The e.xtra
thickness is to enable the lath to better carry the weight of the cornice until fixed ; two or more

Casting Plain Cornices in Fibrous Plaster. 355

ceiling or wall laths may be used to make up the desired thickness of a centre body lath. Two or
more body laths are required for larger cornices ; the centre, or main lath, should be placed on edge
and near the centre of the cast, or at a prominent square member, as shown at B. This secures the
utmost available strength for the cast generally, and also strengthens the part which (next to the
ceiling and wall parts; is most frequently handled while being fixed. The K's, i, 2, and 3, are "rib
laths." Xo. I laps over the ceiling and wall laths, and No. 2 butts against them, thus forming a lap
and butt joint alternately, which gives greater strength than if laid all one waj-. It sometimes
happens that space will not permit for overlapping joints, butt joints arc then compulsorj'; but if the
laths are rough, and the can\as well and closely laid and brushed, there is no fear of the joints
coming asunder, especially for small cornices or where there is no great weight or strain. It requires
a considerable amount offeree to pull a well-brushed piece of canvas off a rough lath. Xo. 3 shows
a rib lath in two pieces. This plan is adopted when the angle of the cornice will not permit of a
single straight lath. The joint is strengthened by means of a "lap lath," L. In order to show the
method of making a joint in rib laths where ceiling, wall, or angle space is limited, this lap lath is
placed against the joint ; but where space or angle permits, a stronger joint is obtained by placing
it o\ er the joint. M R is a " mitre lath." It is placed at the desired angle to strengthen the mitre.
Rib laths are placed from 2 to 5 feet apart, according to the strength requisite to support the
moulding being cast. Rib laths take the place of cornice brackets, and connect the ceiling and wall
laths, and pre\ ent the moulding collapsing. Thin laths laid flat are sometimes required to strengthen
the spla)-ed edges of mitres. In order to show the position of the mitre laths more clearly, the
" mitre stop " is omitted.

Having seasoned the mould and stops with shellac, the length of the proposed cast of moulding
is now set out on the mould, the stops fixed with clay, and the whole surface oiled. A sufficient
quantit}' of laths and canvas is cut and laid in a convenient place, keeping each kind and size in a
sejjarate place to save time and confusion. Two sheets of canvas are cut to the length and width of
the mould, allowing for an overlapping margin at the ceiling and wall laths as shown, where it lies
over the mould rims. The length of the canvas is best taken with a rod, and the width with a string,
laid on the mould so as to follow the contour of the mouldings. An ample quantity of long and
short canvas strips to cover the body and rib laths, also a number of small pieces to cover lap and
butt joints, are necessary. The " firsts " and " seconds " are gauged and laid as previously described,
and then the first sheet of body canvas is laid and brushed. Each sheet is laid so as to follow the
contour of the mould, and leave an equal margin at the mould rim.s. Commence the pressing and
brushing from the centre of the mould, and work outwards all ways. The second sheet is laid in a
similar way. The ceiling and wall laths are then laid in position, keeping them close to the mould's
rims, so as to strengthen the outside edges of the cast. They should also be laid so as to give the
strongest and best position for screwing through when the cast is being fixed. The margins (one at
a time) are then turned over, pressed into the longitudinal angles, and brushed. The body laths are
next laid, taking care that their positions will give the best available strength. This is regulated by
the form and size of the mould, but where practicable all laths should be laid flat and on edge
alternately, which gives the greatest resisting force to strains and weights.

When the body laths are covered uith canvas strips, the rib and mitre laths are laid, canvased,
and brushed, taking care that all lath joints are covered with extra strips and well brushed. The
rims of the cast or bearing parts at the ceiling and wall lines are next made up, and ruled off flush
with the mould rims. When the laths can be got close to and nearl\- flush with the mould rims, the
canvas and plaster alone will make up the cast rims. When all is set, the stops are removed, and the

356 Plastering — Plain and Decorative.

cast eased at the ends, and then taken out and placed on a straight board to dr)-. Should the cast
warp slighth-, it can be screwed straight when being fixed. Warping is caused by using bad timber
for the laths, also bj- too rapid or unequal drying. If warping is excessive, or shows as soon as tlie
cast is taken out, it should be weighted down, or screwed to a straight board while green, and left
until dr\-.

Fig. 3 shows the section of a reverse casting mould for a plain cornice, having a projection of
I foot and a depth of 6 inches. The positions and sections of the ceiling, wall, body, and rib laths
are all shown. The various laths will be known by their positions, as already described. As a
further distinction, the rib laths in Figs. 2, 3, 4, and 5 are shown by the greater thickness, which
is about double to that of the longitudinal laths.

Fig. 4 shows the section of a reverse mould for a cornice, having a projection of 9 inches and
a depth of 15 inches. Two body laths, as shown, are required for this size and form of moulding.
Brackets are in some instances used in place of rib laths for coves or other curved work, such as the
" ogee cove," shown in this section of mould. Brackets should be cut to overlap or butt as near as
possible to the longitudinal laths, as shown by the bracket B. Large brackets are made up in two
or more pieces of timber, similar to long templates, as shown for Gothic moulding.s. Brackets are
seldom used for general work. Small curves can be made up with short laths, as shown in Fig. 5.
L is a loose piece in the mould, which is requisite in this section for drawing purposes. It will be
seen that the loose piece is made with a ke\-ed or rebated joint. This keeps it in position, and
prevents it shifting while the cast is being filled in.

Fig. 5 shows the section of a reverse mould for a cornice, having a projection of 12 inches and
a depth of 12 inches. This profile of cornice also requires a loose piece, as shown at I.. Section of
the laths is also shown. As already stated, the curve of the cove is made up w ith short laths.
It is unnecessarj- to use as manj' pieces as shown for this size of a cove. This form is onl)' given
to illustrate the general method for forming curved ribs where brackets are not obtainable.

Fig. 6 shows the section of a rib moulding (4 inches wide by 4| inches d^ep), and the laths.
R is a rib lath, placed from 3 to 4 feet apart. Two longitudinal laths onh- are used for small
mouldings. The laths are placed in the form of a T, as shown at Fig. 7. The top lath is used for
fixing purposes. It also takes the place of rib laths.

Fig. 8 shows the section of a cornice, having a small projection or thickness at the ceiling and
wall members. This is given to illustrate the methods for gaining increased space, .so as to allow
for a requisite thickness of ceiling and wall laths, where the members are too thin to admit of same.
The method may also be used where an increased thickness of laths is required, so as to give
increased strength for large or heavy work. Reference to the sketch will assist the explanation of
the methods. B is the brick (or other constructional) wall line, and J is the joist line ; P is lime
plaster, and F is the section of a wood fillet used for fixing purposes ; c is the finished ceiling line ;
and \v is the finished wall line. The desired extra space is obtained by extending the outer lines
of the ceiling and wall members, as shown b\- the dotted line at E in Fig. 9, which is a section of the
casting mould. This is done when setting out the reverse running mould. Another way is used
where the casting mould is already made, and is done by laj'ing a thickness rule on the mould
rims, as shown at T on Fig. 9. The e.xtra space must not extend beyond the brick wall and
joist lines. All sketches of fibrous cornices herein given are taken from the finished ceiling and
wall lines, and in each case there is sufficient space for all laths. This hint will be found useful
when setting out full-sized mouldings and reverse running moulds for fibrous plaster work.

Casting Fibrou.s Plaster Enriched Cornices: Bedded Enrichment Svste.m. — These

Casting Enriched Cornices in Fibrous Plaster.

357

enriched cornices are best cast in reverse plaster moulds. This method is expeditious, and pro-
duces accurate and clean \\ ork. There are three systems for forming the enrichments in enriched
cornices, viz, " bedded," " fixed," and "cast." Each system has some individual merit, which may
be of advantage for special purposes. For the bedded system the fibrous enrichments are cast in
long pieces. They are then bedded face downwards in the reverse cornice mould, taking care that
they are accurately jointed and mitred. The whole surface of the mould and the backs of the
enrichments are canvased and brushed, as described for plain cornices, thus forming the plain and
enriched members in one body. As the face of the casts are downwards, and cannot be .seen in the
mould, it requires considerable skill and memory to correctly joint and mitre the enrichments.
This is best done by temporarily placing the casts (face upwards so as to see the joints and mitres)
in position to the desired lengths of cornice, and when the joints and mitres are regulated, the

No.

-Casxi.vg Fibrous Plaster Enriched Cornices by the Bedded Enrichmknt System.
Reverse and Framed Waxed Moulds for Enkich.ments.

casts are numbered consecutively, and laid in the cornice mould in their proper positions and
rotation. The casts are held in position w ith plaster dots to prevent them moving while the\- are
being canvased and brushed with the plain members. A bed for each enrichment must be formed
when setting out the reverse running mould. The bed in this case is made in the outer section of
the cornice, being the reverse of that used for solid work, because the bed has to receive and fit (or
fit at the most prominent parts) the face section of the casts. This and other parts of the process
will be best understood by referring to the illustrations.

The annexed illustration (Xo. 138) elucidates the method of casting enriched cornices in
fibrous plaster by the bedded .system. This illustration also elucidates the method of "moulding"
and " casting " fibrous enrichments, both of which are a part of the work in hand. Fig. i shows a
section and perspective view of an enriched cornice, having a projection about 1 foot 5 inches and

358 Plastering — Plain and Decorative.

a depth of ii inches, iiitendcd to be constructed in tibnais plaster, and the enrichments to be
" bedded." Fig. 2 .shows an enlarged section of the reverse casting mould for the above cornice,
showing sections of the fibrous enrichments and hiths in position. No.s. 4, 7, 12, and 9 arc an
enriched bead, soflfit, dentil, and bed-mould respectively. The section surface is indicated by crossed
lines. The numbers in this case are made to correspond with Figs. 4, 7, 12, and 9, which are the
casting moulds respectivel>- of the enrichments. The dotted lines on these moulds indicate the
back surface of the casts. The back surfaces of the casts in the cornice mould are shown rough or
irregular. The reason for this will be seen in the casting of the enrichments. A reverse casting
mould for a cornice with bedded enrichments seldom requires loose pieces, because the enrichments
act as loose pieces, and tend to free the whole cast from the mould. The enrichments being required
before the cornice is cast, their method of casting claims precedence.

After all the enrichments are cast, they are laid in the cornice mould, as shown in I'Mg. 2.

Having arranged the joints and mitres, and fi.xed the casts with small plaster dots (as alreacK-

explained), canvas strips are then cut to the length of the cornice mould, and as wide as will cover

the plain members between the enrichments, allowing for a margin to lie over the joints and on the

enrichments. Two strips are also required to cover the plain member at the ceiling and wall lines,

allowing for a margin to be turned over the laths. The long strips are laid and brushed as before,

and a .second canvas coat is laid in the same way, and the margins at the ceiling and wall lines (c

and W) are turned over and brushed. The three bod)- laths (15, B, and B) are ne.xt laid, canvased, and

brushed ; and then the two rib laths (R and R) and the lop lath (l) are laid as before. Some men

la\- the canvas in sheets (as described for plain cornices), placing the canvas over all the plain and

enriched members in one sheet, then follow ing with another sheet. This way ma\- be all right for

large mouldings and enrichments ; still it is an unnecessary waste of canvas, as there will be four

canvas coats at the enriched members, besides another coat on some parts, caused by the strip for

the body laths. Long canvas strips laid by the first method enables the work to be well brushed

without overweighting the enrichments. The two coats of long .strips and the lath strips will be

found to give ample strength for ordinary-sized cornices, such as Fig. 2. For large work, laths are

laid in the cavities of the dentils. The laths extend from the inner face angles to the ceiling part

of the rib lath, and then another lath is laid at right angles, and extending to the wall part of rib

lath. The dentil laths being connected with the rib laths are of course laid at intervals. To some

it may appear that there is a great amount of timber required for fibrous cornices, but the total will

not nearly cube to the amount required for the brackets and lath used in solid work for a cornice of

equal girth. Judgment is requisite for the proper placing of laths, so as to obtain the greatest

possible strength. A lath i \ inches wide and \ inch thick, if fixed in the proper place and angle,

will afford as much strength as a lath twice the size laid at random. It will be understood that

laths laid to connect other laths, such as rib laths, are not made up solid at the inter\ening spaces

between the lath and the cast, but are simply canvased, and only brushed on the laths and on the

bod\- of the cast, thus leaving the spaces between the laths and the cast hollow. In man}- cases

canvas strips laid across the ends of the laths, and where they touch the prominent parts of the

cast, and then well brushed over, will be sufficient to bind and strengthen the various parts of the

work. On pencil or ink drawings it is usual to indicate the inner sections of mouldings for ordinary

plaster work b\- parallel lines. In this and the following sketches I have used crossed lines to

indicate fibrous plaster ; and I venture to .suggest to architects to adopt this method (unless colours

are used), so as to distinguish it from the old lime plaster or " solid work." The method of

moulding and casting fibrous plaster enrichments for fibrous plaster cornices is as follows : —

Moulding for Fibrous Plaster Enrichments. 359

Moulding for Fibrous Plaster. — Moulds for casting fibrous enrichments are usually
made of wax, gelatine being used for undercut work. Moulding pieces are made in lengths
from 3 to 5 feet for small work, and from 5 to 7 feet or even 12 feet for large work, but
there is no limit to the lengths, as fibrous casts may be got out the full length of the
cornice. Moulding pieces are made by casting as many casts of the ordinary size as will make
up the required length. They are then fixed on a ground or a profile, according to their section.s.
For bedded work, a part about I inch wide of the plain members at each side is run with
the profile bed. The joints must be made so that there will be no trimming or jointing on the
casts, because the canvas comes close to the surface and edges, therefore it cannot be trimmed so
easily as solid plaster. Fibrous casts are much thinner than solid plaster, so the depth at the sides
and joints of the moulding piece need not be so great as for solid work. If the .section at the joints
is deep or undercut when using wax, make a plaster piece, as shown at P, Fig. 14, on illustration
No. 138. This allows the mould and the cast to draw, and forms jointed ends at the casts. This
is made as described for a jointed mould in Chapter IX. Long moulds are best made with wood
sides and ends. This method strengthens wax moulds, and keeps those of gelatine straight.
Fibrous laths, or ordinary running rules, are used, and are let in while the wax is soft, or where
practicable they are fixed in a similar position to clay or plaster fences. The wax or gelatine, as
the case may be, adheres to the wood fences, thus giving the desired strength. When the moulds
are done with, the wood is freed from the mould, and the materials kept for future use. These
moulds are termed " framed moulds." Where practicable, the sides and ends of the frame should be
nailed together before being placed in position.

Fig. 3 shows the sections of the moulding piece, fences, and wax mould of the dentil
on the moulding board M B. G is the ground of the moulding piece, and B is the " backing "
which carries the dentils D, forming a " lapping part " of the plain members at the top and
bottom of the dentil. The lapping parts also keep the casts in position while being canva.sed
and brushed, and make a better joint than if made at angles, or at the joints of plain and
enriched members. The backing and lapping parts will be further understood by comparing
I! and B on Fig. 5, which is a sectional view of the cast, and then comparing the section
No. 4 on Fig. 2. The sections of the plaster moulding pieces on all the figures are indicated by
a dotted surface. (This also applies to the plaster fences F and F on Fig. 3.) The section
surfaces of the wax moulds are shown black. On Fig. 3, L and L are sections of the frame laths,
and S is a stay or brace which is placed at intervals to support the mould. The lower frame lath
is temporarily fixed to the fence with thick clay water or thin gauged plaster, and then placed in
position and secured with cla.\- or plaster dots, as shown at C. The high fence is then fixed in a
similar way. After this the wax is poured on until it reaches the level of the low frame, when it is
worked up over the side of the high frame, and then the stays put in where required. The wax is
worked up by the aid of a gauging trowel. For clay work, use the fingers to draw the wax w hen near
the original, so as not to injure the model. After the wax is set. take the fences off, and then the
mould, and lay it on a board as at Fig. 4, which is a section of the mould ready for filling in. The
section of the mould on Fig. 3 is taken through a dentil, and the section on Fig. 4 is taken through
the division that divides the dentils. Fig. 6 shows a section of the moulding piece and mould of the
bed-mould enrichment. This is moulded in a similar wa\- to the dentil, with the exception that
plaster fences are not required. The wood laths, or running rules, L and L. which form the frame,
also act as fences. Fig. 7 shows the section of casting mould ready for filling in. The section at
Fig. 6 is taken through the egg, and the section of Fig. 7 is taken through the spindle of the bead.

36o Plastering — Plain and Decorative.

and in a line with the c;4l; and tiic dart. Tlie dark line in the black surface is the profile of the egg,
and the line above, or finisii of the dark surface, is the profile of sunk part between the egg and the
dart. Fig. 8 shows sections of the moulding piece, mould, and frame lath.s. P is a plaster profile or
" bed " to receive the beads. The backing is, and the s|)indle of the bead (just above the H), are run
with the bed. The beads are then fi.xed over the spindle, the whole thus forming the moulding piece.
The backing and laiJjjing ]jarts are al.so seen at li, which is a sectional view of a cast of the bead.
The frame laths L and L are simpl)- laid on the moulding piece, and the wax poured on as before.
Fig. 9 shows the section of the bead-mould. Tliis and the .section at Fig. 8 is taken through the
spindle. The section of the bead in each case is indicated b}- the dark line in the dark space. Fig.
1 1 shows the .sections of the moulding piece of the soffit, and the frame laths L and L ready for
moulding. The enrichment being undercut, it is moulded with gelatine, which is poured on until
flush with the top edges of the frame lath.s. No ca.se is required, hence the term " open jellj' mould."
If the mould is wide, or thin in ])arts, the jell\- is onl\- run until about i inch from the frame edges, and
the difference made u|) with jjlaster, as shown at Fig. I3, which is a section of the mould. Two ways
are shown for forming the bearing and Iapi)ing jjarts of the soffit. The inner side is formed with a
plain member, as shown on Figs, ii and 2. This is ncccssar\-, because the foliage on the soffit
extends to the plain member, leaving no margin for a bearing or lapping part. On tlie outer side
the foliage does not extend to the plain member, thus lea\-ing a [jlain margin on the soffit, which is
utilised as a bearing and lapping part. A pro\-ision for this must be made when setting out the
reverse running mould, so as to form a raised part in the width of the soffit in the casting mould, as
shown at A in Fig. 2. Where practicable, the latter wa\- is the best, as there arc no plain mouldings
to cast in short lengths, therefore no joints in the plain members, and a better lapping joint is
obtained. This will readil)- be seen b}- comparing the joint at the cavetto members at each side of
the soffit on Fig. 2. An original dentil should be made and moulded to cast as many as will make
up the full length of the moulding piece. The original dentil is made with a slight draft on both
sides, and springing from the inner angles and diminishing to the face and end arris, as from .\ to
D, Fig. 5. The face and end of the dentil being equal in width, the inward draft is impcrce])tible,
especially in a row of dentils. This allows the mould to leave the moulding piece, and the cast to
leave the mould, without excessive dragging or fear of chipping. Where there are several mr)ulfls
required, it is advisable to have a solid moulding piece. This is often compulsor)-, from the fact that
a long moulding piece having several short casts fixed on the ground, one or more casts often come
apart when the first mould is taken off A solid original is then taken out of the mould. If the
enrichment is deep at parts, and has but little draft, these parts in the first mould will be drawn up
and form ragged edges. The edges are cut off, antl the wax smoothed with glass paper, or w ith
Dutch rush, using paraffin oil as a lubricant. Smith's Metal is an excellent material for mould-
ing enrichments for reverse moulds. For permanent moulds, it is a good substitute for wax.

Casting Fibrous Enrichments. — Casting fibrous enrichments for bedded work is a simple
process. Two sheets of canvas are used, but no laths, unless the work is large, such as friezes or
coves, girthing over 6 or 7 inches. The backs and edges of the casts need not be made smooth,
in fact the rougher the better, as this gives a better key when canvased and brushed with the
cornice. After the first two or three casts are taken out, the others will come easily. When the plaster
is set, the moulds (if wax) are placed in warm water to make them more pliable. It will be seen
that the wa.x moulds on the sketches are hollow on the backs. This not only sa\es the wax for
other and immediate purposes, but also allows the mould to be more quickly warmed, and made
pliable. The frames give sufficient strength to a mould, however thin the wax maj- be. As the

Casting Enrichments in Fibrous Plaster. 361

casts are thin, and have no laths, they are difficult to take out without collapsing. This is avoided,
and the cast strengthened, by placing a piece of running rule on the cast, and then laying strips of
canvas about 9 or lo inches apart, and brushing the ends that lie on the cast. These rules are
termed " hand rules." They afford a good leverage, and give a point of resistance to the end of a file
or a chisel when prizing the cast up, and a good grasping place to lift the casts out of the mould.
Fig. 13, on illustration No. 138, is a view of the mould and cast of the bed-mould. This shows the
sections of the mould and the cast, the latter being white and the former black, with the frames at each
side. K is the hand rule, with three strips of canvas, ready for the ends to be brushed. Two rules, one
at each side, are used for wide casts. When the casts are out, the strips are cut at the lower edges
at both sides of the rule, which frees the rule for the next cast. The brushed strip ends are left on
the cast. When the casts are e.xtra thin or difficult to draw, a canvas strip is brushed over the full
length of the hand rule. As previously stated, the dotted lines on the casting moulds indicate the
back surfaces of the casts, but no nicety is required for the backs, as they may run below the
edges of the frames, as shown at Fig. 12. This enables the cast to be drawn out more freely. When
filling in the dentils, small pieces of canvas are required to fit each dentil, in order that the canvas
may be brushed into all the angles, and to render the cast light yet strong.

C.vsTiNG Fibrous Pl.\.ster Enriched Cornices: Fixed Enrichment Svste.m.— Enrich-
ments for this system are cast separately, and then fixed on the cornice cast. The general process
is similar to that used for solid work, except that the fibrous casts are made in long pieces,
and fixed on the cast of the cornice with fine nails, and sometimes with putty and plaster. The
enrichments are cast with t\\o coats of canvas for large work, and one coat for small work. Two
small laths, each from J inch to \\ inches wide, and from ^ inch to '■';, inch thick, are laid along
each side of the cast, and the canvas margins turned over and brushed. These laths are termed
" fi.xing laths," and as their name implies, they are used for fi.xing purposes. When casting the
cornice, corresponding laths are inserted at the beds of enrichments to receive the fixing nails. The
moulding pieces and moulds for the enrichments are formed in similar lengths and in a similar
way to that described for bedded enrichments, with the exception that no bearing and lapping
parts are required. The ground or run profile must be made to fit the bed of the enrichments on
the cornice casting mould. This of course is done when setting out the reverse running mould.
The casts are fixed with fine sprigs, or French nails, using plaster for the side and end joints, as
described for fixing fibrous cornices. Small thin casts may be fixed with fixing plaster alone.
This was the first system used for forming fibrous enriched cornices, and is still the most common
in use, being the most easy, and more like the old or "solid" way. The completed cornice casts
are not so light, or the joints between the plain and enriched members so strong, as b)- the
" bedded " and the " cast " systems, but it allows more freedom for seeing and arranging the mitres.

Casting Fibrous Plaster Enriched Cornices: C.\st Enrichment System.— Enrich-
ments by this system are cast with and at the same time as the cornice, or in other words, the
cornice and the enrichments are cast in one operation, hence the term "cast enrichments." By
this system the moulds of the enrichments are laid in the cornice casting mould, thus forming one
complete mould, which allows the enriched and plain members to be cast complete in one operation.
The moulds are made in long pieces, and jointed as with fibrous casts for bedded work. They are
made with wax or jelly as required, and can be u.sed as "loose pieces."

The annexed illustration (No. 139), drawn to scale, elucidates the cast enrichment .system.
Fig. I shows a combined section and elevation of an enriched cornice. S is the section and E is
the elevation, a on the elevation is an enriched crown-mould. The depth of the flutes is shown by

362

Plastering — Phun and Decorative.

the dotted line on the inside of the section. C is an enriched cove. The profile of the ornament is
expressed b\- the dotted lines on the outside of the section. B is a bed-mould with a raised
enrichment, as shown b)- the dotted line 011 the outside of the section, r, on the section, is a
"pendant patera" wliich is placed at regular intervals on the soffit, as shown in the elevation, and
on the plan of the soffit at Fig. 2. This has a sunk panel (s P) between the pateras. One of the
pateras is omitted to illustrate another method of working, but its position is indicated b\- the
circle line C P. The panels are formed by the circular styles (C, C) which connect the fillets or
straight styles (S, S). In order to show these straight and circular stjdes while being made and
when finished, the joint at one side is shown open, and the other as stopped. The sunk panels

No. 139. — Casting Fibrous Plaster Enriched Cornices hy the Cast System. Combined Plaster and Wax

Reverse Moulds.

can be constructed by two different methods. By the first method, as used in the present case,
the straight styles are cast with the cornice, as shown at S, S on Fig. 3, which is a section of the
casting mould. The circular styles and patera are cast and then fixed between the straight styles,
thus dividing the space from mitre to mitre into panels. For this purpose, a moulding piece of the
combined circular stjdes and patera is made, moulded, and the required number of casts got out.
The plan of the combined stj'les and patera is shown at Fig. 4, and the section at Fig. 5. G in each
case is the ground of the moulding piece. This also illustrates the method of making a moulding
piece for a jelly mould. One end of the ground has splayed angles to form a distinction from the
other. This gives a ready guide for always placing the case on the moulding piece in the same

Moidcliiig and Casting Enriched Fibrous Plaster Cornices 363

position as first made, so that it will not injure the model. This distinctive guide is also used
for correctl}- placing the jell\- mould in the case when casting. The above is the method adopted
when joggles are not used. The pateras in this design spring from or are placed on the surface line of
the st)-les, but in most designs they are placed on the surface line of sunk panels — indeed the\' look
better in the latter \\a\-. The former is only given to show one method of constructing combined
parts. The second method is the reverse to that of the first. The first part of the second method
is done when setting out the reverse running mould to run the cornice casting mould ; the surface
lines of the straight styles must be continued to form one straight surface as indicated by the
dotted line from S to S on Fig. 3 ; this forms a bed for the panels. Moulding pieces of the oblong
sunk panel (S P) and the circle sunk panel (c P), on Fig. 2, are made and moulded with wax or
plaster, and as many casts got out as there are panels in the length of the cornice mould. They
are then fixed on the style surface, as from .S to S, the position of each being previously .set out,
thus forming the style surface into a reverse casting mould, which enables the cornice mould to
produce the sunk panels and the other plain and enriched members in one complete piece. Fig. 6
shows the plan of styles and panels as placed in the cornice mould, s and .s are the sections.
The panel casts (and all other made-up parts of reverse casting moulds) should be fi.xed with
fixing plaster, and then further secured with screws to enable them to resist the damp and repeated
pulling when casting.

Fig. 3 shows the section of the cornice casting mould, with the moulds of the enrichments in
position. The plaster with which the cornice mould is formed is indicated by a dotted surface, and
the wax moulds by black-lined surfaces. A framed wax mould is used for the lower bed-mould
(l! M). The bed in the cornice mould must be made about \ inch larger than the wax mould to
allow for fixing it firmly and true. The bedding is shown b}- the clear space between the main and
the wax moulds. The top bed-mould (.\) is also made with a framed wax mould. Sections of the
frame rules are in each case shown in the moulds. Although not actually required for this section
of cornice, the enrichment mould (.v) is .shown as a "loose piece" to illustrate another method which
is desirable in some works. The method of making an " enriched loose piece " is as follows : —

Fig. 8 elucidates the method of constructing a wax mould to act as loose pieces in a plaster
re\erse casting mould. A run profile, as P, which is precisely the same as the enriched part, is
required as a ground for making and moulding the enrichment with a running mould. As it is
difficult to get a series of wax moulds all one thickness and form on the backs so as to accurately
fit the bed in the main mould, which is imperative for a loose piece, a "run plastcrca.se" is u.sed
to give a uniform shape and size to each length of mould. This is done by means of a running
mould cut to the section of the bed. When the wax mould is made, the back is left rough, to give
a key for the case. The exposed parts of the run profile are shellaced and oiled (but not the wax
mould). Gauged plaster is then laid over the whole surface, and the back formed with the running
mould. The various parts are shown in this figure, and are as follows :— B is a section of running
board on which the profile (P) is run. The dark-lined surface is the wax mould. M is the running
mould with a rebated slipper (s) to run on the side of the running board, and the nib to run on the
running rule (r). The mould with its plaster back is shown in position at .\, Fig. 3. The cove
mould (c) on Fig. 3 ma\- be made in wax or jelly as required. A case or backing for this mould
must be used. The plaster case is indicated by the dotted surface, s is a section of one of the
stays or braces, which are placed at intervals to strengthen the mould. The moulding pieces for
the enrichments are made in long pieces, and the moulds jointed as described for " bedded
enrichments." The moulds (especially if made with jelly) are best when made to the full length of

364 Plastering — Plaiti and Decorative.

the proposed cornice cast. This saves jointini^, and it is as quick and as eas)- to make one lon;^
mould as it is to make three or four short moulds to make up the desired length. A bed for the
enrichment moulds must be allowed for when setting out the reverse running mould for the casting
mould of the cornice. Having run the main mould, and made and bedded the enrichment
moulds, filling in the whole mould to obtain a complete cast now claims attention.

Casting or filling in the mould is performed as described for previous cornices, but in order to
explain a subject in connection with fixing points and patera fixing, in this class of work, further
details are given. Fig. 3 shows sections of the various laths used for the cornice cast. The letters
correspond with those already described, C, \v, B, R, and L being the ceiling, wall, bod\-, rib, and
lap laths respectively. F and F are fixing laths which are laid, can\-ascd, aiul brushed with the
cornice cast so as to form fixing points for the casts of the combined stj'les and patera, as made by
the first method for sunk panels. Fig. 9 shows the plan of the fixing laths (F and F). The position
of the cast is indicated b\- the dotted lines at .s. Similar laths are used for the casts. The
corresponding laths afford secure fixing points for the nails or screws which are used for fixing the
casts to the cornice casts. This method is precisely the same as that used for " fixed enrichments."
A slightly different method is adopted for pateras that are used alone, or fixed on the surface line
of panels. The first thing is to form a series of fixing holes in the cornice cast, each hole being
made in the panel or other part intended to recei\e a patera. This is done by fixing a raised " die "
or block on each panel surface line, as shown by the section of one at n, Fig. 3, and on the plan at I),
Fig. 9. The dies may be cast or cut out of a plaster ground, as required. The diameter of the dies
should be about i inch less than the diameter of the bearing parts of the pateras, so as to allow for
a bearing on the panel as shown bj- the dotted line at D, Fig. 9. The continued double line is the
radius of the die, and the dotted single line is the radius of the patera. When the cornice cast is
being filled in, the fixing laths (F and f) and the " rib fixing laths " (r and R), as shown at I), Fig. 9,
are used to form fixing points, and to strengthen the edges of the holes. The canvas is laid over
the dies, but not brushed on the raised surface. When the cornice cast is set, the unbrushcd can\as
is cut in three or four places — from the edge to the centre — so as to form three or four " tags."
These are left on the cornice cast, and are afterwards used for fixing the patera to the cast. When
the cornice cast is taken out of the mould, the pateras are fixed on it by the aid of two or three fine
nails or screws. The canvas tags are then turned down into the hollow inside of the patera and
well brushed, thus giving a secure fixing and a sound joint. Fixing by the tags alone is sufficiently
strong for small and light hollow casts. The tags may be supplemented by brushing canvas strips
over the inside joints. Tow is also used for this purpose. It makes a strong joint, and is useful for
small or acute angles, or where there is insufficient space for canvas. When brushed, it clings to
dry fibrous work even better than canvas.

Fixing Fibrous Pla.STER Cornices. — Fibrous plaster cornices, and most fibrous works, are
fixed with French nails or with screws. The latter are preferable, because screwing up is not so apt
to jar or chip the work as the hammering of nails. Brick or stone walls require to be "plugged,"
and wood fillets fixed on the plugs, to form a ground for fixing the cornice on. The fixing is done
through the ceiling and wall members and laths. The ceiling member of the cornice is fixed to the
joists. If the joists which run longitudinally at two sides or ends of room are not in a line with the
ceiling member, a special fillet must be fixed between the joists for fixing purposes. If the walls
are lath and plaster, the members can be fixed to the wall or partition studs. Fixing grounds must
also be inserted at the joint where large cornices are made in two or more longitudinal sections.
Iron girders or other iron framework intended to be covered with fibrous plaster should be

Fireproof Fibrous Plaster. 365

jjerforated or so arranged that it can be plugged or wedged to receive fixing fillets. Concrete walls
or ceilings can be constructed with wood plugs, fillets, or concrete fixing blocks. These are built in
as the work proceeds, as described for concrete stairs and floors. When all the fibrous work is
fixed, the joints and mitres, also the countersunk screw holes, are stopped with plaster gauged with
size water. The parts to be stopped and made good should be wetted with size water. This stops
the suction sooner than pure water, and therefore is not so liable to soften the plaster. Xail and
screw heads (unless they are galvanised) should be coated with shellac before the holes are stopped,
to pre\ent rust or discoloration appearing on the surface of the work. When fibrous plaster
cornices are made to the finished ceiling and wall lines, they should be fixed on the floating coat,
and the setting laid up to the cornice. If the walls are set before the cornice is fixed, the setting
can be cut down to the floating, allowing a margin about i inch w ide at the ceiling and wall lines,
and when the cornice is fixed the margins are made good. The margins maj- also be left while the
setting is in progress. This makes a cleaner and stronger joint than if fixed direct on the finished
surface. \Mien it is imperative to fix on a finished surface, the cast rims should be made true and
strong, and well stopped when fixed, to prevent the joints opening. Fibrous work is often required
to be fixed on old plaster work. In this case the walls ^unless lathed) must be plugged at inter\als
to form fixing points. All joints between fibrous work and solid work should be stopped with
plaster gauged with lime putty water and slowed with size water. The putty water corrects plaster
expansion and renders it more tenacious. Wide or deep joints should be made up with plaster
and canvas. When the rims of the casts are increased in thickness to allow for thicker laths,
the cornice is fi.xed to the brick and joist lines. This should be done on the actual work before the
mould is made. Room must be allowed for this, also for a fillet. Unless these precautions are
taken, difficulties will arise when fi.xing, and the cornice may not have the same projection at the
ceiling and wall lines as shown on the drawings.

FlliROUS Plaster Me.VSUKEMEXTS. — .All dimensions for fibrous pla.ster work should be
taken (where practicable) from the actual work or foundation intended to be covered, for unless
this precaution is taken, it will be necessary, in many cases, to alter the size of the fibrous work
by cutting or making it up to fit the structional work, which, in some instances (especial))- iron
work), var)' in size or form from the drawings. The expense incurred by the alterations has
generally to be borne hy the plasterer, whereas it should be paid for by the contractor, who.se
work is not in accordance with the drawings. Even if allowed for, it is often the cause of much
unpleasantness. When setting out fibrous work for cornices and ceiling or wall panelling, care
must be taken to allow for the extra thickness required for the lath framing in large casts, also the
wood fillets or wall battens that are used for fixing purposes. It is usual to allow about i inch
for lime plaster, but the thickness for fibrous work will \ary from i inch to 2 inches or even
3 inches for large casts or heavy work.

Fireproof Fibrous Pl.\ster. — Plaster is one of the best known fire-resisting material.s,
but when used in combination with wood, as in fibrous plaster, there is not a sufficient body of
plaster to protect the wood backing, and unless proper precautions are taken, fibrous plaster may
be overcome by fire in the same way as any wood work used in the construction of buildings.
The outer or plaster surface will resist the effects of fire equally as well, if not better, than
constructional w ood work. The weak part is the back where the wood is exposed to flames,
as for instance, fire that takes place in overhead floors, wood partitions, or similar constructional
wood work. When fireproof work is required, it is necessary to protect this wood backing.
This may be done by brushing all exposed wood and canvas with plaster gauged with slag dust,

3<56 Plastering — Plain ami Decorative.

or with fine engine ashes, or tile, brick, or terra-cotta dust, or by covering these parts with slag
wool, either in a dry state, or mixed with gauged plaster. Can\ as maj- be rendered incombustible
by steeping it in a strong solution of borax. A solution of phosphate of ammonia with sal-
ammoniac will answer the same purpose. Wood is also rendered less incombustible bj- immersion
in either of these solutions.

Metal sheets or laths may be substituted for the wood backing and laths, and in some cases
wire-netting for the canvas. When the Alexandra Palace was destroyed by fire in 1873, it was
stated in one newspaper that the rapid progress of the fire was due to the fibrous plaster with
which the ceilings and principal decorations were composed. This statement is incorrect. The
rapid spread of the fire was entirely due to the great amount of constructional wood u.sed, large
coves, domes, and other surfaces being simply covered with a thin body of fibrous plaster work, the
large spaces behind causing draughts, which drew the flames to the wood work, and practically
fed the fire. The fire, I believe, originated by a plumber's "devil" on the roof P'ragments of
fibrous plaster found among the ruins were blackened and scorched on the outer surface, and
in some instances the wood backing was charred down to the plaster surface. J. Wilson, a
plasterer, who was at work on the original building, and at the rebuilding, had several of these
fragments in his possession for many years. When the Oxford Music Hall was burnt down in
1868, there was a small portion of fibrous plaster which resisted the effects of external fire, the
greater portion being destroyed by inward fire and falling walls, yet some small fragments found in
the debris showed that the plaster, although practically u.seless, had to a certain extent resisted the
combined effects of fire and water. I am not aware if this fibrous plaster was specially prepared,
but being painted, it would probably better resist the effects of fire. Fireproof fibrous plaster
may resist fire and for a time stay its progress, but unless the work on which it is fixed is
also protected, it w-ill be impossible to make the building fireproof

FilsROUS Pl.\ster Di:cok.\tive Sheets. — Fibrous plaster sheets have been successfully used
as a decorative finish or co\ering for plaster walls and ceilings, and for wood, stone, and iron
surfaces. Fibrous plaster sheets can be made to any desired design or size, and are constructed as
follows : — For example, take the design as being 3 superficial feet before being repeated. The
design having been modelled, it is then moulded with wax, and as many casts got out as
will make a moulding piece 9 or 12 feet long, as required, the width being the same as the
original model, or it may be repeated and made 6 feet wide, but in either case it must be jointed
so that the design will intersect at the sides and ends. The depth at the sides and ends of the
ground of the moulding piece to the surface must not be more than jV inch, this being sufficient
to allow the mould to give the line of the joint. This is moulded with wax, jelly, or plaster,
as desired. Wax is the best for most purposes, as it is clean, sharp, durable, and pliant for a
large flat surface. The mould is filled in with extra fine plaster, gauged firm with the best size
water, and then a .sheet of extra fine and thin canvas is laid and brushed, taking care that the
ground of the cast is not more than ,',. inch thick. No wood is used for this kind of work. The
cast is taken out and laid on a flat surface to dry. After this, it can be rolled up in a loose form,
as to " Lincrusta Walton." If colour is not objected to, the cast can be rendered very tough by
coating or soaking it in a strong solution of hot glue. The casts are fixed on walls or ceilings
with strongly gauged putty and plaster and size water. If the walls are dr}-, the casts can be
fixed with a paste composed of white lead thinned down with linseed oil, and then gauged with
fine plaster. The fixing material, whatever it may be, is spread e\enly on the wall, and the cast
pressed on to it, using flat pads or brushes to press them down. The joints are then stopped in

Casting in Plaster and Tow. 367

the usual way. An example of this work, designed by Mr W. Emden, architect, can be seen on the
staircase walls at St James's Hall, Regent Street.

Muslin Plaster Casts.— Fine and thin casts for plaques, delicate panels, or coving
wood or metal work, are made with one or two sheets of fine but open muslin and plaster, made
in a similar way to fibrous plaster sheets. The casts are light and strong, and being as thin as
paper, they are quite flexible, and may be bent to any cur\-e. They can be fixed with glue, w ith
white lead, or plaster, according to the material to which it is to be fixed. Muslin plaster casts
may also be used for a variety of decorative purposes, by fixing a .series of casts on to a canvas
ground, and then fixing the whole in one piece, or several large pieces, to make any desired
design.

PLA.STER AXD Tow Casts. — Tow which has been well chopped or teased, and then gauged
\\ ith plaster and size water, can be used with advantage for small or thin work, also in thin or
narrow parts of moulds, when canvas would be too thick or difficult to turn over. A little teased
tow makes an excellent material when dipped in gauged plaster for fixing plantings on fibrous
work, also on solid work. The planting is fixed on the face of the main cast with "seconds,"
in which short chopped tow has been mixed. The cast is then turned over, unless in a position
to work it from both sides, and the joint is brushed over with ".seconds," and loose dr>' teased
tow laid on and over the joint, and then brushed with "seconds." This makes a strong and clean
joint. When casting pieces for plantings, or fixing on the work, tow may be used for the whole
cast, or for the sides onh-, according to the size or kind of work ; but in either case the whole of
the tow should not be dipped or brushed with plaster, so as to leave a part at the edges in a loose
and dry state. This dr}- part, which projects above the edge of the cast, is brushed on and over
the joint of the main cast when fixing. This makes a strong key to unite the two pieces together.
When casting circular casts for planting, a combination of canvas and tow will be found useful,
canvas being used for the inside or flat parts, and tow for the small parts and the outside edges.
\o wood or wire will be required for small w ork, if tow, well saturated with plaster, is used to form
an edge. It has already been stated that plaster and tow are used for modelling figure and
theatrical decorations and properties ; also that tow, instead of canvas, is used for fibrous plaster
in France. The further use of tow will suggest itself for man)- plastic purposes. Tow is ver}-
strong, as may be proved b)- tr}-ing to break a single fibre.

Rapid Plastering. — Ancient records and examples afford ample evidence that plaster slabs
were used in remote ages by the Egyptian, Saracenic, and Moorish plasterers. Slab plastering
is used for producing ceilings and partitions in plaster or cement, whereby the operation of
" lathing," " pricking up," and ■ floating " are dispensed with. Moreover, the delay necessary to
allow the lime plaster to dry after each of the above-named operations is avoided, as the
foundation or body of the ceiling is made beforehand, and requires only to be nailed up and
set with a thin laj'er of plaster or cement in the ordinary way. Papier-mache slabs were first
used in England by Bielefeld as a substitute for lath and plaster on the ceiling of the Reading
Room at the British ]\Iuscum. The present form of plastic slabs is the outcome of fibrous plaster.
The rapid system of plastering by means of fibrous plaster slabs and a thin setting coat was
patented in 1875 by R. W. Hitchins, a London plasterer.

These slabs consisted of a layer of plaster, two sheets of canvas, and a lath in the sides.
They were about I inch thick, and the sides and ends bevelled so as to overlap each other. In
1SS2 Hitchins obtained a provisional protection for "improvements in, and in machinery for
making slabs of plaster or composition for ceilings and other purposes." The plaster was

368 Plastering — Plain and Decorative.

gauged by machinery, and the shibs made in a continuous Icngtli, and cut with a guillotine knife
to the length required. Hand-made slabs have been successfully made, but machine-made have
not ])roved in practice what was advanced in theory. The advantages claimed for slab work are
rapidit}-, strength, cleanliness, and lightness. It is rapid because there is no lathing or lime and
hair required, and the slabs arc fixed and the surface set in one operation, therefore there is no
waiting for each coat of plaster to dr)'. Strong, because having a certain ainount of plasticity,
and being bound with canvas, they are not liable to crack or fall when subjected to the vibration
of machinery, or the moving of heavy goods above. Clean, because being made in the work-
shop, and only requiring a setting coat when fi.xed, there is little or no dirt and rubbish caused
in the building. Light, because it is nearlj- one-third the weight of three-coat plaster work. It
is practically .sound and fireproof, and is far superior to match boarding, owing to its greater
resistance to fire. This fact is so recognised by the Fire Insurance Companies that the premiums
are less for plaster than for wood linings for walls and ceilings. The London School Board are
equalh- agreed as to the dangerous character of match boarding, and have adopted slab plastering
for their new schools. It can also be made and fixed in much larger sections than is possible
with match boarding, and there is no shrinkage or opening of joints, therefore no harbour for
dirt and \crmin, as is often found in match boarding. This proves its superiority from a sanitary
point of view. Slabs can be made to an\- desired size or form, but they are generally made
2 feet 6 inches wide, and in lengths from 3 feet to 4 feet, the lengths being so regulated that the joints
will come on the centre of the joists. For special purposes the lengths and widths are regulated so
that whatever way they are fixed the joints will be on the centre of the joists. When dry, they
can be cut with a saw to fit an)- angle, or make up small parts. They are generally made from
i inch to f inch thick, according to the class of work for which they are intended. The thickness
should also be regulated according to the distance apart of the joists. For instance, slabs i inch
thick, when fixed on joists 12 inches apart, will stand the strain of trowelling while being set,
and the)- will resist vibration or o\erhead rolling or falling of hca\y bodies ; but if the joists are
14 or 15 inches apart, the slabs should be f inch thick, to give them equal power for the increased
span. Increased thickness also renders ceilings or partitions more sound-proof. The slabs are
made with one face left rough to receive a finishing coat when fixed. The other side being
smooth, the\- can be used for temporar)- building by fixing the smooth surface outward, and then
stopping the joints with plaster, and colouring the whole as required.

Fibrous slabs can be advantageously used for counter ceilings, and for pugging or deafening
boards, also for covering wood or iron work as a protection from the effects of fire. They may
also be used for warehouses and similar buildings, where time is a desideratum. Plaster being the
principal material, and the most in bulk, that is used in their construction, great care is requisite
in its proper gauging and general manipulation, for unless this is attended to, the slabs will be
soft in body and unequal in surface hardness. Plaster that is excessively or unequally gauged
becomes soft and spotty, i.e., alternately soft and hard patches, and it will not stand the test of
time like the old-fashioned lime-and-hair plaster work, which is improved by repeated gauging
and working. It may be thought that the setting coat will give a hard and uniform surface.
The setting will certainly cover, and for a time hide the slab's defects, but the work will never
be sound, safe, and satisfactory. It is well known that no superstructure or veneer, however
strong in itself, can be laid sound and solid on weak or unequal foundations. Soft or spotty
slabs are not onh- difficult to set, but take nearly double the time required for well-made slabs.
These defects, which are often the results of unskilled labour, are liable to bring a useful branch

Rapid Plastering.

369

of the plasterer's craft into disrepute. Slab-making is a useful branch of the craft, as it can be used
for the employment of plasterers during frosty weather when building work is suspended.

Fibrous Pl.\ster Slab Moulds.— Following the proper rotation in the manufacture of fibrous
slabs, the method of mould making is given first. Slab moulds are usually made on a bench, the
top surface of which forms the surface of the mould. They are termed "bench slab moulds," to
distinguish them from an independent mould. The top of the bench is generally composed of plaster
or Portland cement, and sometimes wood, iron, or zinc sheets are used, but plaster being the readiest
and cheapest, it is best for temporary purposes. It will be seen by the illustration ^Xo. 14OJ that
this bench is made to contain four moulds, each one being for a full-sized slab, viz., 4 feet by 2 feet
6 inches. The frame of a bench this size is generally supported on eight legs, but if the top rail is
extra thick and well secured, six legs will be sufficient. The bottom long rails are fixed on the
inside to give greater leg room for the worker. A centring of rough board Ct) is nailed on the

li^

T. fc.)

No. 140.— Bench Slab Mould.

frame, keeping the joints about \ inch apart, to allow for any after-swelling that may ensue after
the plastic top surface is laid. On this centring the bench rules (B r) are fixed. They form a
permanent bench edge and fence to keep the plaster surface in position. The bench rules are
3 inches wide and \ inch thick, and planed on the upper and outer surfaces. Two or more widths
may be required for the ends of the bench, to allow for fixing points for the mould rules and the
clip screws. Having fixed the bench rules firm and level with each other, nails are then driven
into the centring surface. They are placed about 4 inches apart, and left projecting, to form a key
for the plastic top. Neat plaster is generally used for the finished surface, but owing to the
continual damp when in use, it docs not wear well. A more durable surface is obtained by
admixing i part of ground lime to 3 parts of plaster, and gauging it stiff. Hydraulic lime gives
better results than chalk lime for this purpose. For permanent purposes nothing equals Portland
cement, or iron plates, or zinc sheets. If plaster is used, it must be seasoned with linseed oil,

37° Plastering — Plain and Decorative.

though Htharge oil applied hot makes a better and harder surface. Soft soap should not be used,
because although it stops the suction, it does not harden the surface, and the plaster is apt to scale
and chip when used for slab-making. The soap}' nature makes it difficult to rc]5air. Ha\ing
finished the surface, it is set out into the mould sizes. The sides and ends of the moulds are formed
with wood rules, termed "mould rules." They are about 2 i inches wide and \ inch thick, and in
lengths as required. They are planed on all sides and edges, and are brushed with liquid shellac.
The shellac tends to harden the surface and prevent the oil or grease from being absorbed when
casting. This also allows the slabs to lea\e the mould more freel)% and the rules to be freed from
plaster splashes with greater ease. The long and cross mould rules marked .\ are fixed rules. The
rules marked U are loose mould rules. The cross ones fit into sockets which ha\c been pre\iously
cut in the long mould rules, thus keeping the four cross ones in position. The four cross fixed
rules (the a's) hold the loose front rule in its longitudinal position. This is locked by means of the
three clips as shown. C shows an enlarged view of a clip. It revolves on a .screw, thus forming a
speed}- fixing, and alwa}-s on the spot and read}- for use. The finished bench is about 2 feet
6 inches high, or according to the stature of the worker. A man can work with greater ease and
reach farther over a low bench than he can o\-er a high one. A platform is sometimes made under
the bench, resting on the lower rails, for storing cut laths, &c. Never keep canvas underneath, as
it is apt to become hard or lump}' through plaster splashes. Can\as is best kejjt o\erhead within
ea.s}- reach. The mould rules are sometimes held in position b}' means of pegs or pins, but the
above method with the fi.xed and loose rules and the clips is the quickest and most reliable way for
ensuring an equal size and form of slabs. Smaller slabs can be cast out of the same moulds b}'
laying width rules in the mould as required. It sometimes hap]:)ens that slabs from different
makers are sent to one place. It is therefore advisable to have the maker's name on each slab as a
means of identification. This also forms a good advertisement, and is done at a small cost by
fixing a metal or hardened plaster name-plate on the surface of each mould, as shown in No. 4
mould. The foregoing explanation of the bench slab mould in the illustration will make the
method of making and its use tolerabh' clear. The other sketches on this illustration elucidate the
method of making slabs, which is as follows : —

Fibrous Plaster Slab-Making.— The materials for, and the method of making fibrous
slabs, are as for fibrous plaster plain panels. But an additional bod}- coat of plaster, alone or with
other materials, is given, to make up the requisite thickness. The canvas is coarser and more open
than for fine fibrous work, and the frame laths vary from i inch to \\ inches in width, and from
\ inch to f,5 inch in thickness, the -lengths being regulated b}- the size of the slabs. Various
materials are gauged with plaster for the body coat. One of the first used was fibre or coir. This
is the outside coating of cocoa-nuts, and may be obtained from matting factories. Waste fibre or
short ends are also used for slab-making. A mixture of fibre and sawdust in equal parts gives
good results. Mr T. Jones, a well-known Liverpool plasterer, makes good slabs with only sawdust
and plaster for the bod}-. Waste cork, bark from tan-pits, peat moss, shavings, straw, ha}-, bracken
or ferns, reeds, rushes, bamboo and other canes (split and whole), and similar materials have been
emplo}-ed as aggregates for this purpose. When bark or similar materials are used, they must be
beaten or chopped to free them from lumps, and also dried, before gauging with plaster. Coarse
plaster alone is sometimes used, but this makes the slabs hea\-y and brittle ; while if gauged with
fibre or sawdust, or both in combination, the coarse plaster is less heavy and more tenacious. The
moulds are usually oiled with Gallipoli oil (a cheap class of sweet oil). Another way is to grease
them with a " tallow pad." This is made by laying about half a pound of common tallow in a

Fibrous Plaster Slabs. 37'

double ply of canvas, about 8 or lo inches square, and then tying up the ends with a string. If
the tallow is hard, beat it on a wood block until the tallow will work freely through the canvas.
The moulds are quickly and more equally greased with the tallow pad than with oil. The slabs
also lea\e the moulds freely, cleaner, and with less chipped edges. When the moulds are in good
working order, they will only require greasing once or twice per day, and then using a solution of
soft soap for the other casts. Having cut as many laths and sheets of canvas as will last for a day
or more, and greased the moulds, the gauging is next proceeded with. Gauge as much plaster in
a pail as will cover the surface of the mould with a surface coat about \ inch thick. This must be
gauged stiff and quickly. Also gauge another quantity of plaster with size water. Both gauges
should be done at the same time, a man gauging the " neat plaster" while a boy gauges the " sized
plaster." All the plaster should be scraped out and the pail washed out after each gauge.
Pour the neat plaster into the mould, and spread it with a laying trowel ; then Ia>^ a sheet of
canvas over it, leaving an equal margin lying over the mould rules or rims (as described for
plain panels), and then with a trowel press and lay the canvas evenly and close up to all
angles and sides of the mould. Next charge a large brush (an old stock brush will do with
sized plaster, and brush the whole surface, to thoroughly incorporate the surface coat and the
canvas in one body. After this, brush the bed of the laths, and Ia\- them in position, as shown
b)- the four L's in No. i mould, and then brush the laths and fill up any crevices that maj' be
left between the laths and the sides of the mould. While the laths are still moist, turn the
can\"as margins o\er the laths, and brush them well into the angles. The body coat is then
gauged and laid flush with the mould rims and scratched. The body material is usually termed
" fibro," and, as already stated, consists of coarse plaster alone, or more often gauged with an
equal part of fibre or sawdust. Whatever material is used for the body, the plaster must be
gauged stiff, and the aggregate mixed with it until the whole is of the consistency of well-
tempered coarse stuff. While the canvas is still moist, the fibro is laid in the centre of the
mould, and spread with a laying trowel, then ruled flush with the mould rims ; and before the
fibro is set the surface must be well scratched with a coarse broom or a wire drag, so as to give
a good key for the setting coat. One sheet of canvas is sufficient for ordinary work, if the plaster
is good and properly gauged. Two sheets are used for special work, or where the joists are extra
wide apart.

When the slabs are set, turn the clips, and take off the loo.se front rule and the loose cross
rules, and then insert the blade of a trowel in between the slab and the bench, and ease the slabs.
The}- are then taken out and laid on a " slab rack." The novice had better tr\- " his 'prentice
hand " with one mould at first, and when he has mastered the gauging, noted the time of setting,
and the amount of materials required for one mould, he can fill in two moulds at the same time,
filling in Xos. i and 3 first, and while they are setting, fill in Nos. 3 and 4. The moulds are filled
in alternately, to allow more space and freedom for working. This also allows more time for the
first or intermediate slabs to set. \\'hen the slabs are taken out, it is usual to stack them on
edge in racks. The racks are so arranged that there is a A inch space between each slab, to
allow a free current of air. The racks are fixed in a drying-room, which is heated bj- coke fire,
or if time or atmosphere permits, the slabs can be dried by air currents. After they are dried,
they are stored closelj- together on edge. .Another way is to la\- them on flat slab racks, which
are made to the same size as the slabs, and are formed with wood fillets about 1 inch wide and
A inch thick. A rack is laid on the floor, and then a slab laid on the rack, and so on until
the stack is man-high. This keeps them from buckling. On no account should slabs be laid

372 Plastering — Plain and Decorative.

close together until tlioroui^dil}- dr\-, as any contained moisture will render the plaster soft, and
the slabs weak and flabby. The slab stacks should be kept in a dr\- jjlace, and where there is
a strong current of air. K (illustration No. 140) is the plan of a single slab rack. l> is a wire
drag. This is formed with a wood stock about 6 inches long, 2 inches wide, and \ inch thick.
Into this is fixed a series of steel wires about \ inch in diameter, and placed about \ inch apart.
The wires should be flattened at the points. The drag should be drawn along the surface in a
zigzag form, holding it at an angle of 70°, so that it will give a wavy key. It may not be
generally known that a series of zigzag indentations will afford a stronger key than a series of
straight indentations. Both forms are shown on the plan of a slab s.

Setting Fibrou.S Plaster Slab.s. — Fibrous slabs are fixed with i^,-inch galvanised nails
having good-sized flat heads, the nails being about 6 inches apart. When the slabs are all set, the
joints are stopped with plaster, gauged with size water, leaving the surface rough. For common
work they are set with gauged putty and plaster. If required for immediate use or painting, they
are usually set with Parian, adamantine, or other white cement. Owing to the dry and porous nature
of most slabs, it is necessar}' to correct the excessive absorption before commencing the setting, or the
stuff will be difficult to trowel off, and liable to peel. The absorption may be stopped by brushing
the surface with size water, and following on with the gauged putty and plaster as quickly as
possible. If setting with white cement, the slab surface should be brushed with a thin solution
of the cement intended for the setting coat, and then following on as before. This is best done
by one man brushing the surface with the solution, and his partner following up and laying a
skimming coat with a float. After this is all done, one man lays a thin finishing coat with a
trowel, and his partner follows up and trowels off. The whole is then brushed off in the
usual way.

Fireproof Slabs. — As already mentioned, plaster is one of the best-known materials for
resisting the effects of fire, and to obtain a fireproof slab and the requisite strength it is necessary
to use only those aggregates wliich are of themselves fireproof. Therefore, for this form of slab
wire-netting is used in place of canvas, and fine slag, brick, tile, or engine ashes instead of fibre
and similar vegetable aggregates for gauging with the plaster. The wire-netting should have
a mesh from a \ inch to i inch, according to the required strength of the work. The wire is
cut to the size of the mould, and laid so as to be in the centre of the thickness of the slab. This
is done by laying the gauged plaster, mixed with an equal part of fine slag (or any of the other
named aggregates), into the mould until about half full. This stuff is then beaten down and
the wire laid in position. The remaining half of the thickness is made up with the same gauge,
beaten, and ruled off flush with the mould rims, and the surface scratched as before. The moulds
are the same as those u.sed for fibrous slabs.

Salamander Slab.s. — Salamander slabs were patented by R. W. Hitchins. They are formed
in a similar way to fibrous slabs, and are composed of silicate cotton and plaster. When these
slabs are backed with silicate cotton they will withstand for a lengthened period a degree of heat
which no other known material employed for building purposes can resist.

Combination Sl.\b.s. — The foregoing notes demonstrate that silicate cotton is an
important factor in fireproof plastic construction. This substance, which is also known as slag
or mineral wool, being an incombustible, and non-conductor of heat or sound, is now largely
used in conjunction with plaster for fire and sound proof purposes. It can be manipulated by
means of wire-netting, and applied in a sheet-like form for fireproof plastering slabs, pugging,
and fibrous plaster casing for iron columns and girders, and similar wood constructive work.

Metallic and Portland Cement Slabs. 373

It is a waste substance from iron smelting furnaces. The wool is formed by causing a jet steam
to pla\' upon a stream of molten slag. Its great power as a non-conductor of heat is due to the
fact that it contains a great volume of air. It is a well-known scientific fact that the material
containing the highest percentage of air is the poorest conductor of heat. Air is subtle and
rapid in movement when unconfined, and so slow to convey heat, except by its own motion,
that it is at once the very best distributor of heat, and also the greatest barrier to its
transmittal. 192 lbs., or i cubic foot, of raw slag make 192 lbs. of .slag wool, or 8 cubic feet,
hence it is seen that the wool encases eight times the quantity of air that the slag did. It is
also an antiseptic, that is, a substance which a.ssists or arrests putrefaction ; therefore it is an
excellent sanitar>- material, and will not harbour vermin. These properties render it useful for
many plastic purposes. Fibrous slabs, and in fact all kinds of fibrous work, may be rendered
practically fireproof by a combination of silicate cotton. This is done by encasing the upper or
back surface of the slabs with a layer, about i inch thick, of silicate cotton, which is secured by
means of wire-netting, and then fastened to the slabs. D. Anderson & Son Limited of Belfa.st,
London, and Glasgow, who are the largest manufacturers of silicate cotton in the United Kingdom,
supply this material for slab-making and other fireproof and sound-proof purposes in plastic and
building purposes.

FiBROU.S Metallic Slabs. — Fibrous metallic plaster is a substance used for plain and
decorative slabs and mouldings, &c., patented by the author. The work can be made to any
desired form or size, whether plain or ornamental, and is intended for external purposes. It will
resist rain and frost, and other atmosjsheric changes. It has been u.sed as a constructive and
decorative covering on wood framing for \arious buildings. It was employed for a portion of
" Old London " and other e.xposed buildings in several of the South Kensington Exhibitions
designed b}' Mr Wilson Benison, Architect to the Royal Agricultural Society. One-half of the
facade of the American Exhibition, London, 1887, is executed with this material. It still wears
as well as the solid-built half of the facade. It was used in the construction of a shooting-box in
Belgium, and for many other similar buildings. The materials for fibrous metallic slabs have
already been described.

External Slabs. — These slabs are made in a similar wa\- to firejjroof slabs, substituting
Portland cement for plaster. They are generally made about i inch thick, the lengths and
widths being regulated to joint on the wood standards or framing on which they are intended to be
fixed. Owing to their hardness when set, provision for the screw holes must be made while they
are being cast. This is done hy means of pegs which are let into the mould surface, or as described
for perforated slabs. Where lightness is desirable, coke-breeze or pumice-stone should be used
as an aggregate in the proportion of i of cement to 3 of aggregate. Pumice-concrete weighs
about 25 per cent, less than ordinarj' concrete. The slabs are set with neat Portland cement, or
the Portland cement may be gauged ^\•ith lime putty, as alread)' described. The smooth face can
also be used on the outside, and the joints neatly stopped w ith Portland cement, or thej- can be
panelled by fixing small cement mouldings over the joints. The foundation for the slabs is thin
wire-netting, or perforated metal sheets, tow being employed for acute angles. Slag wool in
conjunction with cement, and held in position by wire-netting, is used for backing up parts where
exposed to excessive heat. The slabs and mouldings are fixed with screws, but for fireproof
purposes they are so arranged that they can be hung on metal hooks, or screwed from the back, so
that no metal work appears on the outer surface. The inside fastenings are covered with a similar
compound. Although it is not advisable to hasten the setting of Portland cement for solid or

374 Plastering — Plain ami Decorative.

constructive work, it may be done for this class of work without fear of failure. The quick setting
may be obtained b\- mixing various materials with the cement, as already described.

Rkei) Slabs. — The use of reeds or rushes in connection with plaster dates from the earliest
period of plaster work. As already stated, reeds were used by the ancient plasterers long before the
Christian era. They were used by the Eg}-ptians and the Saracens in the construction of their
mo.saic and plaster work. Reeds are also found in the earliest examples of English plaster work,
and thej- ha\e been used up to the present time in the Midlands for the construction of plaster
floors. As a substitute for wood laths, they have been employed up to the middle of the present
century. They are also used in Germany in the construction of plaster blocks and slabs. Reeds
are found in large quantities in the Fen districts. They are light, tough, and pliable, and form an
excellent strengthening material for many plastic purposes. Reed slabs are made in similar moulds
and ways as that used for fibrous slabs. The whole thickness of the slabs is composed of plaster
(fine and coarse in equal proportions), with two layers of reeds. The reeds are placed in the centre
of the slab's thickness, one ]a>-er crossing the other at right angles. The slabs are stacked and dried
in a similar way to fibrous slabs. Bamboo makes an excellent material for strengthening slabs or
other plastic work. The Japanese use plaster and bamboo for constructing some of cheir idols.

A. & O. Mack's Patent Slabs. — Mack's patent slabs are largely used in Germany and
America in the construction of partitions, ceilings, and fireproof floors. They are made in
various forms and sizes, and are usually composed of neat plaster. The slabs vary in thickness
from I to 2 inches, and are perforated longitudinally with round channels.

Grooved Slabs. — Grooved slabs are made in a similar way to reed slabs. They arc usually
composed of neat plaster, and vary in thickness from i inch to \l inches. Although simple, they
are patented abroad, the merit claimed being the form of groove. The grooves are undercut, so
that the finishing coat, when applied, will have a perfect dovetail at each groove. The grooves are
about ] inch wide, and \ inch deep, and \ inch apart, and are formed by means of metal fillets,
which are inserted in channels in the surface of the mould, and are drawn out when the plaster is
just set, and before it begins to swell. Flexible fillets fixed on the surface would not be quite so
co.stly as the sliding metal ones, and would answer the purpose equally well. Flexible fillets can
be made with rubber, leather, or with gelatine, treated with bichromate of potash, which renders
them insoluble in water. Undercut grooves may also be made by simplj- drawing an undercut
drag or scratcher across the slab surface while the plaster is in a soft state.

Perforated Slabs. — Perforated slabs are an American invention, by which the slabs are
constructed with a series of ]ierforations for fixing purposes, each perforation and the whole slab
being strengthened by wires. The moulds are made of wood or metal, with a series of wood or
metal pins or pegs on the surface. The pegs are tapered and fixed about 9 inches apart, in rows
to correspond with the ceiling joists, and left projecting flush with the mould rims. The wires are
stretched longitudinally from end to end of the mould, and twisted or coiled round the pegs. They
are coiled loose, so that they may draw off the pegs, and are placed near the centre of the slab's
thickness. The moulds are then filled in with plaster in the usual way.

FiNLSHED Face Slabs. — Finished face slab.s, or "plain face," as they are .sometimes termed,
are used for panel surfaces, ceilings, covering rough surfaces, and a variety of other plaster purposes.
They can be made in any desired shape and up to 60 superficial feet in size. They are n:ade in
similar moulds, and by the same method, as used for plain fibrous panels. Plate glass is sometimes
used for the mould surfaces. This produces a fine, smooth, and polished slab surface. Kerosene
oil or salad oil is employed for oiling the glass. The anne.xed illustration (No. 141) elucidates the

Finished Face Slabs.

375

method of making plain face. Fig. i show.s the plan of the ca.sting mould and the various lath.s in
position. The mould rules (the M R's) are 3 inches wide and i^ inches thick. Two sides are fixed,
and two are loose. The latter are held in position by the former, and locked by the four clips H.
Finished face slabs are either made with flush joints or with rebated joints. The latter waj- is used
for the present purpose, and its use will be seen when fixing. Provision for the rebated joints is
made b\- fixing rules (i| inches wide and ,1 inch thickj on the mould surface, and close against the
mould rules. Fig. 2 is a section of the mould and laths taken at T in Fig. i. m is the wood and
plaster surface, and R and S are the end and side sections of the rebating rules. The other letters
refer to the slab, the making of which is next described. The letters on Figs. 2, 3, and 4
correspond with those on Fig. i.

F,6 I

F,6 5

* mm

TfTv/^unrvn-TUTxrir^

Fib 3.

■■■m,

C.2;

:«s

<f^' *

No. 141.— Finished Face Slab Mould, showing Slab durinc the Process of Making.

Various ways are used for placing laths in finished face slabs and other large fibrous casts.
The main object is to obtain the greatest lateral and transverse strength and surface rigidity
with the least amount of wood. The plan here adopted of using thin laths, and laying some
on their flat for fixing, and the others on their edges for strengthening [jurposes, is the best up-
to-date method, and renders the work not only strong and easy in fixing, but also light and
flexible. This slab is 6 feet by 6 feet, and \\ inches thick at the edges, and it will be seen that
the surface is divided b\- laths into sections about i foot square, and a few at the sides half that
size. The positions of the laths should be marked on the mould rims, as shown. This saves
time, and allows the various laths to be laid uniforml)-. Begin laying the lath from the sides
of the mould, and work towards the centre. Two sheets of canvas are used for this class of work,

376 Plastering — Plain and Decorative.

and they are laid and brushed as described for i)hun panels. This done, the laths are laid and
brushed in their due rotation, as follows :— First, lay the four rim-fixing laths (A i, 2, 3, and 4) on
their flat, and close to the mould rules, then lay the two body-fixing rules (a 5 and 6) on their
flat, and then lay the four frame laths (B 1,2, 3, and 4) on their edge, and close to the mould rules,
taking care to break the joints over the rim-fixing laths, as shown. The rim and body fixing
laths are i^ inches wide and ] inch thick, and the frame laths are \ inch wide and j inch thick.
The decreased width of the latter is to allow for the thickness of the rim-fixing laths and the
plaster and canvas. The lengths in all cases are made so that each lath will butt against the laths
that traverse at the ends. The canvas margins are then turned over and brushed. Fig. 2 shows
sections of the laths at the angle of the cast at T, Fig. i. A i is the end section, and A 2 the side
section of the rim-fixing laths. v> i is the elevation of the frame lath. The end section of B 2 is
indicated by the dotted lines, the plaster by the dotted surface, and the canvas by a thick and
rough line. The letters on the sections correspond with those on the plan, Fig. i. When the
canvas margins are brushed, lay the two body-bearing laths (B 5 and 6) on edge on the body-fixing
laths (a 5 and 6), and cover them with canvas strips, and press them well down on the surface.
The two body-bearing laths are i inch wide and \ inch thick. The three rebated body laths
(c I, 2, and 3) are next laid on edge, canvased, and brushed. They are \\ inches wide and
I inch thick, and rebated at both ends so as to lap over the rim laths, as shown at C, Fig. 4.
The four rows of rebated rim laths (d i, 2, 3, and 4) are next laid on edge, and canvased
and brushed. They are l] inches wide and \ inch thick, and rebated at one end so as to
lap over the flat fixing laths, as shown at Fig. 3. This is a section taken through F G on
plan, Fig. I. The letters and sizes correspond with those on the plan. The two rows of
plain rib laths (K and ?:) are next laid, and canvased and brushed. They are i^ inches wide
and \ inch thick, and square ended. The upper edges of the frame laths (B i, 2, 3, and 4)
and the body-bearing laths (B 5 and 6) are then made up and ruled flush with the mould rules
or rims. This gives resisting points and bearings w hilc the cast is drying and being fixed. The
clips are then turned, the loose mould rules released, the cast taken off the mould, and then the
rebated edges scratched with a sharp steel drag, to give a key for jointing. Fig. 5 is a section
of an external angle of the cast, showing the rebated edges and ke}-ing. It will be seen that
all the laths are \ inch thick, with the exception of the four frame laths, which are f inch wide, and
the two body-bearing laths, which are i inch wide. All the others are \\ inches wide. The slab
surface is divided into three longitudinal sections by the fixing lath laid flat, and the bearing laths
laid on them and on edge, which act as fixing and bearing points, the other laths being used for
the general strength of the slab. Slabs that can only be fixed on the outer edges are constructed
with thicker frame laths.

It may seem to the casual observ-er that there is a great quantity of wood required, but this
is not so, considering that there are no plaster laths required for the ceiling or other surface. In
fact, the total contents of wood in i superficial yard of slab do not amount to i cubic foot.
There is also another matter in connection with this, viz., that there is a very small thickness of
plastic material, the average thickness being only \ inch. As to the objection of expense, that
must of course be estimated by the importance of the work. Like many other good and useful
works, the cost of labour e.xceeds that of materials.

F1BROU.S PL.V.STER L.ATHS LAID DIAGONALLY. — Laths laid diagonally in finished face slabs,
or other fibrous plaster work, render it rigid and strong. The laths are laid on edge, therefore
they can also be used as fixing laths, as well as doing duty as body laths. This is a more simple

Fibrous Plaster Slabs for Gesso and Sgraffitto.

377

and cheaper way than that given for finished face slabs. This diagonal system of laying laths
will be found useful for most kinds of fibrous plaster work. The method of making diagonal
lathed work is elucidated in the annexed illustration (No. 142). This shows the plan of a fibrous
plaster panel, with the frame and diagonal body laths in position. The laths marked with As are
the frame laths, the B's are the long diagonal body laths, and the C's are the short diagonal body
laths. The frame laths are U inches wide and \ inch thick, and in lengths and widths according
to the mould, allowing the usual space at the end for canvas and plaster. All the body laths
are made one width and thickness, viz., 1} inches wide and i inch thick. The long body laths are
cut to the necessary lengths, so that they may be equally spaced. The short body laths are cut
equal to the spaces between the long diagonal laths. All these laths are laid on edge. The
frame laths are laid first, and then the canvas margins are turned over and brushed. The long
diagonal laths are next laid and brushed, their position and width apart being regulated by the
marks which have been previously marked on the mould rims. The short diagonals are then laid
and brushed. This method is more expeditious than the last-mentioned process, but it requires
more wood, and the work is generally heavier, and not so strong. Care must be exercised when
fixing this form of work that the nails or screws are accurately centred, so as to catch the centre
of the laths. The method of placing diagonal laths may be
u.sed for many other purposes besides plain panels. The
distance between the body laths may vary from 8 to 14
inches, according to the size and requirements of the work.

Fi.xiNG Finished Face Slabs. — Finished face slabs
are fixed by means of screws. They are countersunk, and
the heads are coated with thick shellac to prevent rusting.
The holes are then brushed with size water, and stopped
with plaster. The joints are brushed with size water, and
covered with canvas strips (about 2 inches wide), and
brushed, then stopped with plaster and ruled flush with
the surface with the aid of a wooden rule. After this the}^
are smoothed with a margin trowel, or a small thin joint
rule and a damp brush. Slabs made with a square flush

joint require great care when being stopped, and unless firmi)' fixed at the joints, and carefully
stopped, the joints will show or crack when finished, especially if there is any overhead jarring.
There is no fear of this with rebated joints. The canvas covering makes it impossible for the joints
to open or crack, besides there is a sufficient body of plaster to make a smooth and fair joint.
Another way is to cover the joints with small rib mouldings, thus forming a panelled ceiling, at
a small extra cost. The slabs can be made to any shape, ,so that jianelled ceilings or walls of
any design can be constructed by this method.

Gesso Slabs.— Slabs as a groundwork for gesso work are made similar to finished face
slabs. The first sheet of canvas should be laid near the surface, so that the key for the deep
parts of the gesso may be easily obtained by scratching the plaster surface with a fine and sharp
steel drag. This will fray the canvas, and give a pliant >-et strong key for the gesso. The use
of plastic slabs enables gesso, sgraffitto, fresco, or similar works to be done in the studio.

Sgraffitto Slabs.— Slabs for sgraffitto are constructed by first making a wood frame to
the desired size. This is then lathed, or covered with strong wire-netting, or with metal sheet
lathing. The frame may form the edges and ruling-off" points, or rules may be temporarily fixed

No. 142. — FntRous Plaster I'anei., with
Diagonal Laths.

378 Plastering— Plain and Decorative.

on the outsides of the fnime to give the desired thickness of plastic material. The frame is then
plastered with any dcsirctl lime or plaster in the usual way.

Fresco Slab.s. — Slabs for fresco work are made as above, an equal and uniform suction
being an important requisite for fresco work. Two sheets of wire-netting should be used, a close-
meshed sheet being fi.xed first, so as to form a backing to regulate the thickness of the plaster
work key that passes through the main sheet. This may also be done b>^ temporarily fixing
boards or a fibrous slab at the back of the main sheet. The upper surface is then laid with any
desired lime or cement. This form of backing is also useful for sgrafifitto slabs. The plastic
materials being regulated at the back as well as the front surface ensures a uniform thickness,
and therefore an equal surface suction.

Pugging Slabs. — Pugging or deafening slabs are made in much the same way as fibrous
slabs, their width being regulated according to the space between the joists, the length being
3 feet, and thickness i inch. For ordinary work they are composed of coarse plaster and fibre,
sawdust, or any other similar aggregates, with a sheet of canvas in the centre. I^'ircproof pugging
slabs are composed of coarse plaster gauged with fine slag, brick-dust, coke-breeze, or fine engine
ashes, having a sheet of wire-netting in the centre. They are laid on wood fillets, previously
nailed on each side of the joists, and bedded or stopped with coarse plaster gauged with size
water. For best work, a double la\-er of slabs is u.sed, the intermediate space being filled in with
slag wool, or coarse plaster gauged with sifted breeze or ashes.

Hardening Fibrous Plaster Slabs. — Several materials and methods are used for
hardening neat plaster and fibrous plaster work, but they are too costly, slow, or unsuitable.
After many experiments, I have found that the following solution gives the best results. For
reference purposes it is named " Litharge Oil." It is made as follows : —

Litharge Oil is compo.sed of i lb. of litharge (oxide of lead), i lb. of paraffin wax, \ lb.
of resin, and i gallon of linseed oil. It is best made in an iron pot over a slow fire. The
wax is melted in another pot and poured into the oil-pot. The litharge and resin, in a powdered
state, is then put in, the solution being kept constantly stirred. It is allowed to cool before using,
and when required, should be melted and applied hot on the work, which has been previously dried.
The oil is laid on with a brush, and the work should be made warm, to allow the oil to penetrate
into the surface, and to work freelj'. One coat is generally sufficient for ordinary purposes. When
two coats are applied, the first is allowed to stand in a warm place for two or three hours. The
second coat is then applied in a hot state. This process renders the work so hard that it will
resist a nail. It becomes waterproof, and is effectively protected against any atmospheric
changes. If the back of fibrous work is alone coated with this oil, the work will resist the action
of saline acids and damp. It is also useful for indurating work intended for exposed positions.
The work can also be painted and gilded soon after it is cool. This solution does not enter into
any great chemical combination with the fibrous plaster, but being of a hardening nature, and
filling up the pores, it hardens the work and prevents the action of moisture. It may be used
with advantage for indurating ordinary plaster for various purposes.

DamI'-Prooe Slabs. — A cheap and ready method for rendering fibrous slabs damp-proof
is done by brushing the backs once or twice with a solution of coal tar or pitch. Pitch, Stockholm,
and coal tar are rendered more durable, damp-proof, and not so readily affected bj- heat, if mixed
with fine brick dust, or ground lime. This solution should be well worked on the slabs with a hard
stumpy stock brush. The process is effectual for slabs intended for damp or e.xposed positions.

Fibrous Plaster Sign-Boards. — Another and novel use for fibrous plaster has recently

Damp-proof Fibrous Plaster Slabs. 379

arisen in the manufacture of fibrous plaster sign-boards, letters, and advertisement tablets. There
is a recent patent for fibrous letters and sign-boards, but fibrous advertisement tablets have been
in use for the last decade for theatrical, patent medicine, and similar advertising purposes. The
tablets are modelled, and contain raised figure and emblematical subjects ; and are then painted,
coloured, and gilded as required. They are lighter and cheaper than wood or iron, and more
effective and durable than paper. Letters can be made in every conceivable type and size, and can
be made singly, or on skeleton wire-work, to form clear and effective adverti.sements. Sign-boards
are made plain for painting or writing on. They are also made with the letters standing out in
bold relief, all in one piece, and being cast in moulds, they are perfectly true and uniform in shape,
with a fine surface. They retain gold longer than wood, are light and strong, and perfectly weather-
proof They are made in a similar way to fibrous plaster panels, fine wire-netting being substituted
for canvas, and tow for deep parts. They are usually made with a wooden frame round the edges,
and a skeleton back frame for fixing purposes. A series of plaster moulds of letters is kept for
stock purposes. These letters are laid on a moulding board to form the desired words. The joints
are temporarily stopped. The frame is laid so as to form a fence, and then the main cast is made.
Ornamental signs and letters are first modelled and then moulded from the clay with wax, jelly, or
plaster, and then cast, thus producing an exact facsimile of the modeller's work. A ready way for
making a sign-board with raised letters is done by fixing two thickness rules to the desired width
on a bench, filling in the space with cla\-, ruling it flush with the rules, and then cutting out the
letters down to the bench. When finished, the clay is coated with shellac and oiled. A wood
frame is then laid on the surface and the cast filled in, using tow or perforated metal for the deep
parts of the letters, and wire-netting for the main surface. The frame is so arranged with a wood
fillet that the wire netting can be fastened to it. The cast is then dried, and coated with litharge
oil to render it weather-proof. A mould frame made with fibrous plaster, and having an outside
wood or metal member, may also be used for the above method. Fibrous signs may be
supplemented with coloured glass, illuminated with inside lights, also by gas or electric light, and
made in a variety of other ways to form a bold advertisement.

Fibrous Plaster Blocks. — These have been used in America and German)- for constructing
partitions, ceilings, arches, and domes. The blocks are made in wood moulds, metal or plaster
being used to form divisional parts. They are composed chiefly of strong coarse plaster. Reeds,
sawdust, fibre, wood-wool, or ashes as aggregates are occasionalh" used. They are made in various
forms and sizes, according to the intended purpose. For partitions, they are generallj- 3 feet long,
I foot wide, and 2\ inches thick. Every three blocks of this size measure 2 yards, counting both
sides, and each block weighs from 15 to 25 lbs., according to the size of the perforation, the amount
and class of aggregate. They are made with round perforations extending longitudinall\- from end
to end. This is effected by means of rods covered with brown paper to allow the rods to be
withdrawn, or the rods are brushed with a thick solution of clay. The perforations may also be
made by tapered rods. They are laid in the mould the reverse way, alternately, so as to give a
uniform strength to the block. They are sometimes grooved on all edges to give a ke>- for fixing
purposes. They are also made with dowel holes for fixing purposes, the wood or metal dowels
being inserted as the building proceeds. When thej- are fixed between iron or wood joists, the
exposed parts of the joists are covered with wire-netting to give a key for the finishing coat.
Domes or arches made in one piece or in large sections are generally composed with a skin of fine
plaster, and backed with coarse plaster, and left with a finished face. Xo originality can be claimed
for plaster blocks, the idea being taken from the stalactite ceilings of the Moors.

CHAPTER XIII.

REVERSE MOULDING.

Reverse Moulding — Its Uses and Terms — To Set Out a Reverse Running Mould — To Make a
Reverse Casting Mould for Cornices— Panel Mouldings— Rib Mouldings— Plain Capitals,
Diminished and Fluted Columns and Pilasters, and Plain Columns— Hollow Cores and
Column Casts— Reverse Moulds for Overdoors.

Reverse Moulding. — Reverse mouldin<j is an English invention, introduced about thirt\--five
years ago by J. M'Donald, who was formerly foreman for Desach\- ; since then he has held
an important post with Messrs G. Jackson & Sons, London. It is the natural outcome of
fibrous plaster work, and derives its name from the simple reason that the methods used are
the reverse of those which are generally cmplo\-ed for the formation of plaster and running
moulds. The running mould for forming a reverse casting mould is cut from the inner profile
of a design or moulding, being the rev'erse wa\- used for an ordinary running mould, which is cut
from the outer profile of a design. A casting mould made b}- the re\erse method requires no
model to mould from, but is run direct with a reverse running mould, which is the contrary way
employed for an ordinary casting mould taken from a model or moulding piece. A reverse piece
mould for a cornice is run in one operation, while an ordinary piece mould is formed b}- hand from
a model which requires complicated manipulation. The uses of and the improvements in reverse
moulding during the last two decades have developed in a variety of ways. The most important
improvements are due to one Tom Sweeney, formerly an employe of G. Jackson & Sons.

The art of reverse moulding is more expeditious than ordinary piece moulding, and a round
saving is efiected in general fibrous plaster work, but it is not applicable for figures or foliage. It
is adopted advantageously for casting concrete. Being comparatively new, its practice is limited
to a few. There being no general terms to distinguish the various stages and processes of the
work, it is necessary to define the nomenclature adopted, and describe the general process, before
describing the individual parts.

The "ground line" drawn on the design of the intended moulding represents the ground or
bench line, and is used for setting out the form and position of any required loose pieces, as well
as the width of bearings for the nib and slipper of the running mould. The " .square edges," or
" striking off" edges, forming the rim of the casting mould, are the same as the ceiling and wall
lines, and are usually square with each other. A " loose plate" is a plate temporarily screwed on
to the running mould to form a bed for a " loose piece," which is a movable portion of the cast-
ing mould. It is made where any member, or part of a member, is undercut, or which would
prevent the cast from drawing. The loose piece comes with the cast when the latter is taken out
of the mould. It is then taken off the cast, and replaced in the mould. If a loose piece should
get broken when taking it off the cast, the pieces can be put in their places in the same manner as
a piece mould, and any defects stopped with clay or plaster, and the seams cleaned off the cast.

Reverse Moulds for Cornices.

38«

Large loose pieces are made lighter and stronger by inserting canvas strips in their centres while
being run. As there is little or no swelling in a fibrous cast, the loose piece is easily removed by
gentle tapping with a mallet. The core is a bracket made of wood, brick, or other rough material.
It is used in large work to save plaster, and prevent swelling. The casting mould is simply
termed " the mould " to distinguish it from a running mould. Committing the foregoing terms
to memory will enable the method of setting out, and making of reverse running moulds, to be
more readily followed, and afterwards put into practice. The accompanying sketches illustrate
the method of making a reverse running mould, and casting moulds for various purposes. As the
foundation of reverse casting moulds lies in the setting out of the running mould, a section of the
running mould for each casting mould, and also a description of setting out one for a cornice casting
mould, is given.

To Set Out a Reverse Running Mould.— The annexed illustration fNo. 143) elucidates
the method of setting out a reverse running mould for a cornice. Take Fig. i as the given
profile of a cornice to be produced in fibrous plaster or cement. As already explained, the first

X CciUIMO LiMC.

No. 143.— To Set Out a Reverse Ru.n.ning Mould for a Cornice.

thing required is the ground or bench line (.\), taking care to leave sufficient thickness between the
most prominent points of the moulding and the ground line. This thickness is the body of
plaster which constitutes the casting mould, and should not be less than i inch thick, because
if less, the plaster dries, and is apt to lift from the bench. When forming the ground line, it must
not be forgotten to have a sufficient depth of the ceiling and wall lines, as they form the rim or
striking-off edges of the casting mould; also continue the line across the wall and ceiling lines to
allow for a bearing for the nib and slipper of the running mould, as B, B on Fig. 2. After having
settled the proper position and length of the ground line, the form of the plate of the running
mould is then set out to the ordinary width, beginning at one end, and continued to the other end,
as shown by the dotted lines which spring from the ground line (for want of space this line is
broken). The space between the dotted line and the inner section of the cornice is the plan of
the mould plate, and of course is precisely the same in form as the section from B to B in Fig. 2.
It may here be remarked that, in order to keep the architect's drawing clean and free from the pencil
lines necessary for setting out purposes, a tracing should be taken from the original drawing, and

382

Plasteriiig — Plain and Decorative.

transferred to ordinary white pajjcr (wall lining paper is good and cheap for this purpose), and
on this the section of the plate and the loose piece and its plate can be freely set out.

Fig. 2 shows the section of the mould plate, and on it the loose piece plate (c). The face of
the bench (a) is the same as the ground line (.\) in Fig. i. It will be seen that the undercut
formed by the cove member w-ould ])revent the cast from drawing out of the casting mould. This
difficulty is got over b\- using a loose piece, as shown. When setting out a loose piece, care should
be taken that it is cut to draw in the same line as the greater portion of the members, as expressed
by the longest side of the loose plate. Loose pieces should also be made with the joints in flat
parts of a member, so that the)- may be easilj- cleared off. For enriched cornices they should
(when practicable) be made in the bed of an enrichment, as an_\- unevenness in the mould at these
parts can be easily made good, and the seam in the cast covered with the enrichment casts. In
this example one joint is made near the centre of a member (the cove), and the other is made in
a line with a straight part of a member (the fillet). The latter way leaves the joint of the loose
piece at an arris, and unless the loose piece is closely fitted for every cast when casting, it will leave
a seam at an arris of the cast, which requires considerable care and skill to clean off. A seam on
or near an arris is more difficult to clean off or make good than one on a flat surface. This form
of joint, although not so good as the first, is given to show what is sometimes used for special

No. 144. — Reverse Running Mould for a Cornice Castinc; Mould.

purposes. It is better than forming one on a small round member, such as the quarter round
below the present joint, as shown in the sketch, or a small bead. It has one advantage, namely,
that a joint on the under part of a member is not so noticeable as one on an upright or vertical
member. Loose pieces should be made large and strong, .so as to lie firm and steady in their beds,
as well as to stand the frequent moving and handling when casting, but not so heavily as to over-
weight the cast. Sharp angles in the bed of loose pieces should be cut off, as shown below c.
This allows the bed to be easily cleaned out, and prevents a sharp edge of the loose piece, which
would wear off, and cause dirt in the joint. These precautions tend to secure a close and even
fitting joint after each cast. The loose-piece plate should always be made large enough to lie well
over the stock of the running mould to give a good bed for fixing.

To Make a Reverse Castinc; Mould for a Cornice. — Having set out the mould
plate, the position and form of the loose piece, and cut the plate for the loose piece, the whole
is horsed. Running moulds for reverse casting moulds require to be more strongly "horsed" than
ordinary running moulds for lime or cement work. Reverse casting moulds are generally
composed of neat plaster, therefore the running mould should be stoutly horsed, to enable it to
resist the force of the plaster when it begins to swell or set while being run. The stock should be

Rujiniug Reverse Moulds for Cornices. 383

from f inch to i;^ inches thick, according to the size of the proposed mould. The strength of the
running mould is greatly increased b)- fixing two handles (one at each end of the slipper; from the
slipper to the nib end of the stock. The fixing point at this end should extend as far as the outer
member of the profile. Two handles allow two men to work freely together, one to push the
mould along, and the other to push and hold the nib of the mould down, so that the mould will
run steady and true, avoiding humps in the work. For extra wide mouldings, the handles should
be fixed on the top of the slipper, as shown at 3 A in annexed illustration (No. 144). This
method is stronger, and gives a better grip for the workers, than if fixed on the inside of the
slipper, as shown by the section of the running mould in the same sketch. One handle is generally
sufficient for small work. There are two methods used for running a reverse casting mould which
requires a loose piece. B)- the first and original method, the main moulding and the loose piece
are run in two distinct operations ; and by the second method, the main moulding and the loose
piece are run in what may be practically termed one operation. For example, take the .section of
the running mould (illustration No. 143) of the foregoing cornice, which will illustrate both methods.
For the first method the mould plate is cut into three parts ; the first and third parts are those
which run the main mould, and the .second or middle part is that beneath the loose-piece plate, or in
other words, the mould plate is cut in an exact line with the side joint of the loose plate. The
three parts are then fixed on the stock exactly in the same position as it would be if in one
piece. This done, the loose plate is fi.xed over the second part of the mould plate, and then the
moulding is run in the usual way. After this, the first and third parts of the mould plate, also
the loose-piece plate, are taken off, thus leaving the second part of the mould plate on the stock,
and with this mould the profile of the loose piece is run, taking care to first shellac and oil the
bed of the loose piece and also the main moulding, to allow the loose piece to be easily taken
off, and any plaster splashes that may fall on the main moulding, while the loose piece is being
run to be cleaned off. It will be understood that the running mould must be muflfled with plaster
before the moulding is run, and after the moulding is roughed out, and the plaster swollen to
its full extent, the muffling is taken off, and then the moulding run off or finished. This allows
the plaster core to swell fully, and the moulding to be run off freel\-.

The second method is employed for the present casting mould, and the process is as follows : —
As already mentioned, the illustration (No. 144) shows the section of the reverse running mould
for running a casting mould for a cornice, as set out in the previous illustration. This section
shows the loose plate and loose-piece plate screwed on the stock, also the handle and the end
section of the slipper. The names of the various parts are shown on each part. The loose plate
forms the bed of the loose piece (c). The dotted line beneath the loose-piece plate indicates the
continued profile of the main plate, which, of course, is also the profile of the loose piece. The
plaster muffling is indicated by the dotted parts outside the profile of the mould plate. In
order to make a true and sound joint between the main and loose parts, about i inch at each
side of the loo.se piece is left unmuffled. The moulding is roughed out, and then the muffling is
taken off, and the finished surface run off.

Fig. I in the annexed illustration (No. 145) shows the .section of the casting mould when run
with the muffled mould, leaving a finished surface at the bed of the loose piece (c), and a finished
part at the joints of the loose piece, the dotted lines indicating the profile and thickness of the
fine plaster used for the finished surface. The bed of the loose piece is next shellaced and oiled,
and then filled in, and the rough surface of the mould laid with fine plaster. The whole is then
run off in one operation. Fig. 2 shows the section of the complete mould with the loose piece (C)

384

P/asfcn'/ig-

Plaiii mid Decorative.

and the finished surface The roii^t^h core and the thickness of the finished surface (with the
joints formed hy the unmuffled part of the running mould) are indicated b\- a rough dotted surface
and a fine dotted surface respectively. By comparing this figure with Fig. i and the section of
the running mould, the whole process will be seen in a clearer light. With regard to the filling in
of the mould, the cast must not protrude beyond the dotted lines that spring from the rims or
" striking-off " lines, as shown in Fig. 2. The striking-off lines represent the wall and ceiling lines,
and any projection be\'on(l these lines would |)re\-ent the cast from being fixed plumb, level, or

No. 145. — Reverse Casti.m.; Mould.
Fig. I. — Section of Mould when run with the .Muilled Running Mould. I-"ig. 2. — Section of Casting Mould with Loose Piece.

square. In some instances, cornice casts are fixed on the ceiling joists and wall iilugs. Where
this occurs, an allowance must be made for this when setting out the running mould. It will be
seen that the formation of a reverse running mould for a plain moulding is simple, and when the
method of setting out loose pieces is mastered (some mouldings require several loose pieces), their
use for a variety of purposes will suggest themselves to the thoughtful plasterer.

To M.\KE A Reverse Casting Mould for Panel Mouldings.— Illustration No. 146

elucidates the method of making a reverse casting mould for sunk panel mouldings for beams,

No. 146.— Reverse Moulds ior Panel Moului.nc.s.

arches, &c. The section of the sunk jjanel casting mould on the running board, with the fixing
nails to prevent the moulding from lifting, is shown at A. One side of the mould is shown
with a plaster piece used as a side j^iece if the side or front is moulded. The other side shows
a board (standing on edge and secured with a rule on the flat) as used when a plain side is
required. E is the section of the running mould for the sunk panel mould at A. The section
of the running mould for the moulded side is shown at D. This moulded side is sunk and rai.sed

Reverse Casting Moulds for Ribs and Caps.

385

to show that the same method of forming the running mould applies to both. If the sunk panels
are required for an arch, the mould pieces must be run on a saddle made to the desired cur\'e
or radius. For circular panels on flat surfaces the mould pieces are run from circular templates,
or by fixing a radius rod to the running mould. The running moulds are set out as already
described. The stock, which, in this case, also represents the profile of the plate of the running
mould, is indicated by horizontal irregular lines, and the slipper by vertical irregular lines. These
remarks also apply to the running moulds in the following examples of reverse casting moulds.
To Make a Rever.se Casting Mould for Rib Mouldings.— The annexed illustration

Xo. 147. — Reverse Moulds for Rib MouLDi.NGb.

(No. 147) shows sections of the running mould (l) and the casting mould (a) for rib mouldings.
There are two methods of constructing the casting mould. By the first, one-half of the mould
is run as a fi.xture, as shown by the fixing nails, and the other is run as a loose piece and held in
position by the side rules, as shown by their sections, j, at the left side, is a fixed rule, which is only
used if both pieces are movable. J, at the right side, is also a fixed rule, and is used as a stay
for the wedge L 1, and K is a movable rule placed along the side of the mould. This method
is better than using wedges between the fixed rule and the mould, as the wedges, bearing only at
intervals on the mould, are apt to break it while being forced home. Again, if the plaster is hot.

No. 148. — Reverse Moulds for Tlain Caps.

or liable to swell or twist, the unequal pressure, or rather the pressure at certain parts, causes the
mould to twist at the intervals, whereas the movable rule has a bearing the whole length of the
cast. Another advantage is, that should the half mould get broken, the rule will keep it in
position. When the mould is filled in, remove the wedges and the side rule, then draw the half
mould with the cast up to the fixed rule, and the cast can be easily taken out. By the second
method, both sides of the mould are made as loose pieces, and held in position by side rules, as
shown. Another wa)- to hold the pieces together is to dispense with the wedges and fixed rules
and use clips, as described for "slab bench-moulds" (page 369). If circle ribs are required, and their
length does not extend beyond their diameter, the inner half is run first, and made as a fixture.

386

Plasteri)ig — Plain and Decorative.

The outer half is run as a movable piece. If a full circle or more than half a circle rib is required,
the casting mould is run the full length required, and then cut into sections, so as to form a piece
mould to allow the pieces to draw easily off the casts.

To Make a Reverse Castinx. Mould for Plain Capitals. — The figures in the annexed
illustration (Xo. 148) show sections of the running mould (M) and the casting mould (a) for a plain
moulded capital. In making the casting mould, first run a sufficient length of moulding to form
the front and sides of the mould, then cut it to the required lengths and mitres, and place them on
a moulding board, as shown. The mould pieces are held in position as described in the previous
example. Casting moulds for circular capitals (commonly called "caps "), also for square or other
shaped piers and copings, are constructed by the above method.

To Make Reverse Casting Moulds for Diminished Fluted Columns and Pilasters.
— The annexed illustration (\o. 149) elucidates the method of making reverse moulds for
diminished and fluted columns and pilasters. There are divers ways in which reverse casting

No. 149.— Reverse Casti.ng Moulds for Diminished F'luted Coi.u.mns a.\d Pilasters.

Figs. I and 2. — Sections of Reverse Moulds for Columns. Fig. 3.— Plan of Ground for forming Flutes.

Fig. 4. — Section of Reverse Moulds for Pilasters.

moulds for diminished fluted columns can be made. The two methods here given — introduced by
the author — are simple in construction, and accurate in production. Fig. i shows the section (one-
half) of the reverse casting mould for a diminished and fluted column. The dotted lines indicate
the top and centre of the mould. It may here be mentioned that two casts are got out of this
mould, and screwed together, to make the complete column. The body of the mould, of which the
dotted surface (.\) is one-half of the section, is first made. This is done by cutting a reverse
running mould of the necking, with about 2 inches of the shaft, and another running mould of the
first fillet of the base, with about 2 inches of the shaft. A part (a little more than half the
circumference) of the necking and base mouldings is run, and each is then cut to the true half
They are then fixed on a stout moulding board or bench (similar to T and T in Fig. 3), so that
a man can work on each side of the mould. The necking and base moulds are fixed a distance
apart, equal to the length of the propo.sed column, taking care that they are Unable with each

Reverse Moulds for Fluted Columns and Pilasters. 387

other, and level at the upper or jointing edges. A board is fixed at each side as a fence. The
intermediate space is then cored out with boards or brickbats and plaster, and the surface made
up with plaster, and ruled with a diminished rule. This rule must be cut to the reverse contour to
that described for forming diminished column in situ. The flutes are next formed. This is done
by first setting out the positions and forms of the flutes on the ground of the mould. A solid one,
from which the mould for the other flutes is taken, is made in the centre of the mould. This flute
will allow the half-column casts to draw ; therefore it is made permanent. The ground should be
well keyed, and a few nails driven in, and left projecting, to give a further key for the plaster with
which the flute is formed. Templates are then cut to the size of the lower and upper diameter of
a flute. They are then temporarily fixed on the body of the mould at the end of the flute lines.
The intervening space is then filled in with plaster, and ruled with the diminished rule. The tem-
plates are then removed, and the circular ends of the flute formed by hand, using the circular end
lines on the ground as a guide. A plaster mould is then taken from this, and the required num-
ber of fibrous casts are got out, and fixed on the ground of the mould. When casting the flutes,
place a lath in the centre of each (as shown by the sections) to strengthen the casts, and allow for
fixing to the body of the mould. It will be seen that only five flutes will draw, viz., the centre,
and two on each side. Provision must therefore be made to allow the flutes to draw in the shape
of loose pieces. Two different methods of making and fixing are shown. For the first method
sinkings are made in the ground to receive the flutes, and hold them in position, as shown at I, i, i,
and \a. The sinkings are first cut to a uniform depth, keeping the ground at an angle that will
allow the movable flute to draw with the cast. A single flute is then made on one of the rebated
grounds, and moulded and cast as described for the centre flute, and then placed in their respec-
tive positions. Should any difficulty occur in cutting the sinkings uniformh', each flute may be
formed on its own bed. The half flute (i«z) requires a deeper sinking, as shown, to act as a
counterpoise for the projecting weight. It will be understood that the bed of each flute is shellaced
and oiled before the flute is made. The same method is employed for the other half of the mould.
It will be seen that these sinkings allow the flutes, which are undercut on the lower sides, to draw
with the cast. When the cast is taken out of the mould, the flutes are taken off and replaced in
their respective positions. An old way is to hold the flutes in position with pegs or French nails,
which are fixed through the flute and into the body of the mould at an angle to allow the flutes
and nails or pegs to draw with the cast. For small work the laths in the flutes may be omitted.
An extra layer of canvas or tow will be ample for the requisite strength.

Fig. 2 shows the section of the casting mould as made by the second method. For this method
a reverse piece mould is made, each piece consisting of a whole flute, two fillets, and two half
flutes, as shown at 3, 3, and 3. For this method a different section, having a larger diameter, is
required for the body of the mould (b), so as to allow for the extra thickness of the pieces. This
is formed by first cutting two templates, one to fit the upper, and one to fit the lower diameters of
the shaft, taking care to allow i \ inches for the thickness of the pieces. They are then fixed the
desired width apart, and the intermediate space filled in and ruled off with a straight-edge, as shown
by the section of Fig. 3. Two templates are then cut to the upper and lower .sections of the com-
bined flute, fillets, and half flutes. They are then fi.xed on the ground of the body of the mould
(as shown by T and T in Fig. 3), and the intermediate space is filled in with plaster, and the upper
surface ruled off with a diminished floating rule, and the two sides ruled off with a straight-edge.
The sides may also be formed by temporarily fixing a board on each side of the template (as
indicated by the dotted lines in Fig. 3) to act as a fence. Care must be taken that the sides are

388

Plastering — Plain and Decorative.

straight, and that the surface or profile is formed with a diminislied floating rule, so as to form a
true and uniform arris. The model of the flute may also be run with the aid of a hinged running
mould. The ends of tlie flutes are then formed by hand, and the model moulded and cast as
before. For large work laths (as shown) are inserted to give strength. The casts are easil)'
extracted by the aid of three strips of dry canvas, which are laid in channels formed in the bodj'
cro.sswise (one near each end and one central). The strips are cut long enough tu Li)- on the
channels under the flutes, and over the sides of body, so as to afford a gri]) when e.xtracting the
cast. The strips also prevent the flutes falling off the cast.

Fig. 3 shows a plan and section of the ground, with the joint lines of the flute and fillet piece
set out. T and T are the upper and lower templates in position on the ground, ready for the model
of the piece to be filled in atB. This also illustrates the method for making single flutes.

Fig. 4 shows a section for a reverse mould for casting pilasters. The flutes may be worked
solid b>' the aid of templates, as described for the columns, as shown on one-half of the section, or
they maj- be cast in fibrous plaster, and fixed, as shown on the other half The sides are held in
position with rules and clips, as shown at C, C. The method of making and using the cli]5S is the
same as described for slab bench moulds in Chapter XII.

To M.VKE A Reverse Casting Mould for Plain Colu.mns.— Illustrations Nos. 150 and
151 elucidate the method of making a reverse casting mould for plain columns, also for making

hollow moulds and casts. No. 150 shows the
section of a reverse running mould (on a running
board) for running a casting mould for a plain
column 4 inches diameter of any desired length.
F is the profile of the mould, G is a wood cleat
screwed on the stock to strengthen the deep
part, and II is the section of a hollow core, as
used for hollow moulds and casts. Great care is
necessarj- when cutting the mould plate to ensure
true fitting of the male and female joints or
joggles, as shown in the section of the casting mould on No. 151. This is best done by first
roughing out the profile on a sheet of zinc, then cutting it through the centre — taking care to cut
it true, so that the two hahcs will fit close at the joint when fixed on the stock — thus allowing
both sides to be placed in a vice and be filed together in one operation, so that both sides of the
profile will be exactly alike. This also enables the joggles to be fitted accurately. This method
of cutting the plate through the centre and filing the halves together will be found useful when
making mould plates for equal-sided mouldings, such as rib mouldings, &c. In making a casting
mould, say for a column 4 feet long, run a full 8 feet length of moulding, and cut the piece in
two, then place one on top of the other, binding them with hoops to keep them together while
casting. This casting mould, as also the other reverse casting moulds here illustrated, may
be called a " run plaster piece mould," as the pieces arc run instead of being made by hand, as is
done in ordinary plaster piece moulds. The joggles in this example are also run instead of being
made by hand. This is a method which I have introduced and used advantageousl)-. The
joggles being run with the mould piece are termed " run joggles," but while they prevent the
mould pieces from moving sideways, they will not prevent the pieces mo\ing lengthways, and
as any displacement of the pieces while casting would cause distorted cast work, this is effected
by converting parts of the run joggles into " stop joggles " to hold the pieces both ways. Stop

No. 150. — Reverse Running Mould, kor Reverse
Casting Mould for Plain Column.

^^^HCllH

Rtm and Stop Joggles.

389

joggles are made by cutting about 2 inches off each end of the male joint, and then " stopping "
a corresponding length in the female joint. The stopping is done by cutting off the desired
length at both ends of the male or raised joint, then oiling the cut parts to prevent cohesion, and
then placing this mould piece on the other, and filling in the female or sunk joint at the ends
with plaster, which are previously keyed and wetted. Intermediate " stop joints " are made by
cutting off a part of the male joint where required, then cutting a hole through the female joint to
allow the plaster to be poured in to form the stop joggle.

At one angle of the section of the casting mould a triangular-shaped block of wood is shown.
This is used as a core in large moulds to save materials and lighten the mould while casting. Two
blocks, one at each side, are fi.xed on the running board before the mould piece is run. After this, the
moulding is taken off, thus forming the splayed angles, one of which is shown on the section of the
mould. The fine and coarse dots on the surface section indicate fine and coarse plaster. It does
not follow that because there are no loose pieces in the mould, the running mould should not be
muffled. When the moulding is roughed out with a muffled mould, it allows the plaster to swell
before the finished face with fine plaster is run, so that the moulding can be run with greater ease
and accuracy. It also allows for the use of coarse plaster. Fine plaster for a large mass is an
unnecessary waste. It is .sometimes required that
the cast should be of a given thickness, so that
it will fit a structural iron column, or that the inner
surface should be of a certain profile. Both these
forms are obtained by fixing templates on the ends
of the mould to act as ruling-off points, or as guides
for working straight or curved rules. The section of
a quarter of a template for this purpose is shown at T,
on illustration No. 151.

Hollow Cores. — The method of making
hollow cores is elucidated b\' illustration No. 150.
H shows the section of a hollow fibrous plaster
core. This method is more often adopted on the

score of economy for permanent purposes than for temporary works. It is useful, however,
for extra large moulds that have to be moved about, and while it saves about one-half of
the weight of ordinary solid work, it gives more than double the amount of strength. The
method of making is as follows : — The wood frame is first made and fixed together before being
used. It should be made somewhat less in diameter than the actual size, so as to allow for
plaster, canvas, and in the case illustrated, for the fine finishing coat of plaster. After the frame is
made and fitted, a coat of " firslings," and then "seconds," and canvas is laid on the bed, and the
frame is placed in position, allowing plenty of canvas for the two ends to overlap the frame.
Another strip of canvas is then brushed over the joint or uncov-ered place, as for fibrous plaster.
Before the stuff is set, the muffled mould is passed backward and forward, to see that there is no
excess of material. The surface should be left as rough as possible, so as to give a key for the
finishing plaster coat. A little teased tow stuck into the fibrous work while soft, and left loose on
the surface, affords a good key. The finishing coat should be laid and run while the core is green.
If the gauged stuff is brushed on, a better key is obtained than if merely laid with a trowel,
especially when following the different curves and deep parts of a moulding. The cross lines
round the frame represent fibrous plaster, and the part with the dotted surface the fine plaster used

N.>.

51. — Reverse Castino Mould for Plain
Columns, showing Run Joggles.

390

P/asfcriiii^ — J Vain and Decorative.

for the finished surface. This method can also be used for some parts of hollow fibrous plaster or
for ordinarj- plaster work.

Hollow Column Casts. — If hollow casts of columns in cement are required, stand the
mould on end, then place a tapered wood core upright in the centre, secured at the bottom end by
inserting the end into a socket which has been previous!)- made in the wood ground. The core is
easily removed after the stuff is set by tapping with a hea\y hammer. The gauged cement is
poured in from the top and rammed home with the aid of a piece of rule having the sharp arris
taken off, or the end of the rammer covered with a [jiecc of felt. This is to protect the surface of
the mould. If a hollow plaster cast of a column or other circular work is required, the mould, if
large or heavy, is rolled on the bench or slung with ropes from the roof, and rolled or turned round

152.— Fig. I.— Elevation of Overdoor, Palace Club, Lon-do.\, Designed and Modelled by Wm. Millar, 1875.
KiG. 2.— Section of Reverse Casting Mould, through A B. Fig. 3.— Section of Reverse Casting Mould,
THROUGH D E.

while the plaster is setting. If fibrous casts are required, one-half of the mould is filled in the way
already described, and having a wood lath at each edge. The joints are kept flush with the edges
of the mould, and when two casts are got out, they are placed evenly together and screwed through
edge laths, and further secured bj^ passing a long strip of canvas previously soaked in plaster.
The wet canvas is pulled backwards and forwards over the joint, and pressed on by the aid of a
stump of a brush fi.xed on a wood lath and worked from each end of the mould. The mould is
then turned over, and the other joint treated in the same way. Another way, useful for white
cement and fibrous plaster work, is to make a rough fibrous plaster core and place it in the mould,
and then fill in the space between the core and the mould with plaster or white cement as required.
The core must be "green" as well as rough, so that the surface material will adhere to the core.
When the material is set, the mould is released, and the cast with the core in one piece extracted.

Reverse Piece Moulding for Overdoors.

391

To Makk Reverse Casting Moulds for Overdoors and Pediments. — Illustration
No. 152 elucidates the method of making a reverse casting mould for an overdoor and pediments.
Fig. I shows the half elevation of a pedimental overdoor 6 feet long in fibrous plaster, as carried out
at the Palace Club, London. This overdoor was designed and modelled by the author, and the
reverse mould was made by C. Handwell. In order to render the method of making the mould
more clear, the various parts of the overdoor, as shown on Fig. I, are described first. A is the
inclined cornice, and D to E is the horizontal cornice. The latter includes the fluted frieze (with the
enriched panel P), and the architrave. The upper and lower enriched bed-moulds, U and L, in the
inclined cornice, are, of course, the same in design as the enriched bed-moulds U and L in the
horizontal cornice. The enriched panel, T, is the tympanum of the pediment. With regard to
making the reverse mould, first set out the plan of the overdoor on a moulding board which would
be similar in form to the elevation. It is not necessary to draw all the lines of the mouldings, the
width of the inclined and horizontal cornices will be sufficient. E.Ktra lines representing the width
of the sides or rims of the run reverse casting moulds of the cornices mu.st be made on both sides of
the width lines, so as to form fi.xing points when the various parts are placed together. If the sides

No. 153. — Pa.nel kor Overdoor, Palace Club, Lo.ndo.v. Modelled by \Vm. Millar, 1875.

are formed with boards the extra lines are not required. The present example shows run plaster
sides and wood sides, to illustrate both ways. The reversed running moulds for the inclined and
horizontal cornices are cut and " horsed," as previously described, but taking care to allow for a
reverse bed for the enrichments, also a bed for the enriched tympanum, as these enrichments are
cast separate and laid in the main mould in a similar way as described for "Cornices with Bedded
Enrichments" in Chapter XII. Having run the reverse casting moulds of the cornices, cut them to
the required angles or mitres and lengths, and lay them on the moulding board according to the
plan. Three rules are fixed to the form of the tympanum on the board, to hold the two parts of the
inclined cornice and the horizontal cornice moulds in position, and prevent them moving inwards.
They are prevented from moving outwards by means of rules and wedges, as alread\- described.
The flutes are formed by making a reverse model of a flute, then moulding it and casting as many
as required, and then fixing them on the frieze. A reverse running mould for the panel moulding
at p is made. Then a length of reverse casting mould is run and cut to the desired angles, and
then they are let into the frieze and the mitres stopped. The returned ends of the horizontal mould
being upright, separate pieces must be cut to fair e.xternal mitres and square ends.

392 P/nsferiiig — P/aiii and Decorative.

The returned ends of the inclined cornices are set out and formed as described for raking
mouldinj^s in Chapter \'II. Fig. 2 shows the section of the casting mould, as from A to B on the
elevation, Fig. i. The section shows the various parts of the mould, also the fibrous casts of the
enrichments. K are the rules fixed at the inside of the tympanum, which prevent the inclined
and horizontal moulds from moving inwards. The inclined and horizontal moulds are indicated
bj' dotted surfaces. C is a cored part in the horizontal mould to save plaster. 1' is the side
.section of a flute, s and s are boards which form the upper and lower sides of the outside
members. L' I. and u L are sections of the two enrichments in the inclined and horizontal
cornices, which correspond with u L and U L on the elevation at Fig. i. T is a section of
the enriched tympanum. These enrichments being composed of fibrous plaster are indicated by
crossed diagonal lines. The sections and positions of these enrichments are given, to illustrate the
method of casting the complete overdoor, this being the form of the mould ready for filling in.
Fig. 3 shows the section of the reverse casting mould, as from the darts at \) E on the elc\ation.
Fig. I. This has the same section as the horizontal mould at l"ig. 2, with the exception tliat a
section of the panel moulding, with a sinking for the panel enrichment, P, is shown. A small part of
the enriched t_\-mpanum, T, is shown. The enrichments u L and u L are the same as in Fig. 2. An
enlarged \'iew of the panel, P, is shown on illustration No. 153. The top meinber of the horizontal
mould in F"ig. 2 is formed in plaster, and is run with the main part of the run mould, as shown at \v.
This way is only adopted where there is an ample splay or weathering on the top, otherwise the cast
would not draw. The best waj- for this purpose is to make a side piece with a board, as shown at
W, Fig. 3. This allows the piece to be taken off after the cast is filled in, and the cast to be easily
taken out. A sufficient sinking must be made in the bod\- of the frieze panel to allow for the
projection of the enrichment. The tympanum is left open to allow for the projection of the enrich-
ment. The grounds of the tympanum and frieze panel enrichments are made about f inch larger
than the openings, to allow for a bedding ground on the casting mould. A corresponding bed,
but double width, is made on the casting mould tcj receive the enrichments. The bedding grounds
of an enrichment and the mould is shown at T and T, on Figs. 2 and 3. The enrichments may
also be fixed on the main cast, as described for enriched cornices b\' the fixed system in Chapter
XII. This method of making a reverse piece moukl for the pedimental part of the overdoor
can be advantageously employed for casting Portland cement pediments in situ, as mentioned in
Chapter VII.

CHAPTER XI V.

COMPOSITIONS.

Papier-Mache — Manufacture anu Uses for Decorations — Stage Properties — Paper Casts without
Moulds— Carton-Pierre— English and French Carton-Pierre— Fibrous Slap, or Patent Wood
— Pate Coulante — Paste Composition — Making Sulphur Moulds for Composition— Casting
AND Fixing Composition— Gesso— Gesso Duro— Method of Making and Manipulating— Patent
Plaster Decorations— D^koria — Smith's Patent Metal.

Papier-Mach£. — Papier-mache, as its name proclaims, is of French origin. Good examples are
still to be found in many French buildings of the sixteenth century. The grand trophies and
heraldic devices in the Hall of the Council of Henri H. in the Louvre, as well as the decorations at
St Germain and the Hotel des Fermes, on their ceilings and walls, are executed in papier-machd.
In 1730 a church built entirely of papier-mache was erected at Hoop, near Bergen, in Norway.
The inside and outside are covered with this material, which was made waterproof and nearly
fireproof by an application of vitriol water, and lime slaked with whc}- and white of eggs. The
decorations of the Pantheon, London, were executed in papier-machd by Bielefeld. In 1847 E. F.
Bielefeld obtained a patent for making moulds for this material ; also for making papier-mach^
maps in relief In 1858 White and Parley obtained a patent for improvements in the manufacture
of papier-mache and carton-pierre. The dome of the Palais de Justice of Brussels, which weighs
16 tons, is composed of this material.

Papier-MAch£ Manufacture.— Papier-mache work usually requires two moulds, one for
the face of the enrichment, and a counter or core mould to form the cast to the required thickness,
which is generally about \ of an inch. The cast is therefore of less weight, and a saving of material
is effected. In some manufactories the paper and ingredients are mixed up in a machine. They
are then rolled out into sheets of the required dimensions, placed into the moulds, and subjected to
hydraulic or screw pressure. The casts are next placed in a drying-room to accelerate their
hardening. When dry, they are carefully trimmed and finished. This substance is used for the
decoration of wood cornices ; the enrichments for cornices and centre flowers are pressed in parts,
and afterwards joined up by mounters. The moulds for stock enrichments arc made of brass,
copper, type-metal, box-wood, or sulphur. Large pieces, such as panels or flowers, are backed up
with w'ood to strengthen them.

Another mode of making papier-macht^ is by gluing or pasting different layers of paper
together, and subjecting them to a high pressure until the different strata of paper become as one.

Yet another method, for architectural purposes, is to make a composition of paper pulp and
resin. This mass is placed in the moulds, and then layers of strong paper are pressed on the pulp
until they adhere and form a homogeneous body.

Papikr-M.\CHE Stac.E Properties. — Modellers and plasterers often find employment in
the property rooms of theatres in modelling, moulding, and making masks, heads of animals (the

394 Plastering — Plain and Decorative.

bodies arc made of wicker work), and architectural decorations for solid or built scenes. I'apier-
mache properties are produced from plaster piece moulds. Large sheets of brown and blue sugar
paper are pasted on both sides, then folded u|) to allow the paste to thoroughly soak in. The first
part of the paper process is known as a " water coat." This is sugar paper soaked in water and
torn in small pieces and laid all over the face of the mould, to prevent the actual paper work from
adhering. The brown paper is then torn into pieces about 2 inches scjuare, and laid o\er the water
coat, and coats of sugar jjapcr are laid in succession in a similar wa)- until of sufficient thickness to
ensure the requisite strength. The various pieces of paper are laid with the joints ovcrla])|5cd.
Care must be taken that each coat of paper is well pressed and rubbed into the crevices with the
fingers, and a brush, cloth, or sponge, so as to work out the air and obtain perfect cohesion between
each laj-er of i:)aper, and form a correct imjjress of the mould. After being dried before a fire, the
paper cast is taken out of the mould, ,trimmed up, and painted. A clever man can, by the use of
difiercnt colours and a little hair, gi\e cjuite a different apjiearance to a mask, so that several, taken
out of the same mould, will each look quite different. The use of different coloured papers enables
an)- ])art of the previous coat that may not be covered to be seen and made good. Some property
men do not u.sc a water coat, but dr)- the mould, and then oil or dust the surface with French chalk
to prevent the cast sticking to the mould. Others simply paste one side only of the sugar paper
that is used for the first coat.

Papier-MAche Moulds. — A cast is sometimes required of some part of a building, furniture,
or an ornament, which cannot be taken in a plaster mould, or a wa.x or claj' squeeze. In such
instances a paper mould, made as follows, maj- be substituted. Brush several sheets of sugar paper
with clean cokl water, and la)- sheet on sheet to keep it damp. When the pa]jer is pliable, liut not
wet, lay small pieces on the object to be cast, and press and rub them on with the fingers, modelling
tools, and a brush. After the object is all covered, lay brown paper (pre\iously pasted) in the
same waj-, rubbing it well into every part. Give it four or five coats, and when drv, take it off
carefully. If possible, make a case by laying plaster over the back before taking the mould off;
but if not possible, a plaster case with care may be made after the ]japer mould is taken off. When
drj', give the mould a coat of linseed oil, antl let it stand for twent}--four hours, then gi\e it a coat
of shellac, and it is ready for casting.

To M.-\KE Paper Casts without Moulds. — Paper casts, suitable for .some purposes, may be
made without making a mould, as follows : — Paste some sugar and brown paper on one side, dip the
sugar paper in water, and roll it in a damp cloth. Fold up the brown paper and set it aside, ready
for use. Then tear the sugar ])aper into the required sizes, and la}- it ]3iece by piece until the object
is all covered, using a brush and a modelling tool for jaressing it into ornamental parts, taking care
that there are no ridges or lumps on the surface. Then lay a coat of the brown paper, keeping it as
smooth and uniform in thickness as possible ; and finally finish with a coat of sugar paper,
leaving the surface smooth and fair. When dry, it is carefullj- taken off, and strengthened by coating
the inside with glue. If the object being imitated is on the round, such as a figure or vase, the cast
is cut vertically on both sides with a sharp knife, to free it from the object. If the object is not
much undercut, one side only of the cast is cut, and then eased off by degrees. If this is done
carefully, the cast will spring back, or it may be bent back to its place. The joints are then glued,
and pasted over with paper. It must not be forgotten to oil, or dust the object with P'rench chalk,
to prevent the mould or cast sticking. If the pasted papers, when laid aside to absorb, should
become fixed or difficult to open, dip them in water, which will free them. Paste is made with flour
and cold water well worked together, then boiling water is poured on, and the mass well stirred.

Carton- Pierre Mamifactitre.

395

Permanent paste, as used in Italy, is made as follows :— Dissolve i oz. of alum in i quart of warm
water, and when cold add flour until of the consistency of thick paste, then add i oz. of resin, i oz.
of sugar of lead, and as much boiling water as is requisite for the desired thickness.

Cartox-Pierre. — This substance has a paper base like papier-mache, and is used for similar
purposes. It is an improvement on papier-mache, and was first introduced by M. Miziere, a Parisian
modeller, and further carried out by M. Hire, another Parisian modeller, who reduced the paper to
a pulp, mi.xing it with plaster and dissolved glue. This substance, however, was coarse in texture,
and had to be coated with [Master, which again had to be cleaned up by hand. These disadvantages
were entirely o\ercome by M. Romagnesi, who, by reducing the (laper pulp to a fine state, adding
glue, and mixing whiting as required, was enabled to take very fine lines from delicate originals.

The decorations of the principal apartments of the Tuileries, some in the Louvre, the Palais-
Royal, and the Prince of Wales' house at
Sandringham, were composed of carton-pierre.
It was the leading material for internal
decorations in F"rance and Belgium. Statues
of all dimensions are made in carton-pierre,
and have the advantage of being very light.
The annexed illustration (No. 154) shows
two candelabras in carton-pierre manufac-
tured by Messrs Jackson & Son, London, who
are the principal manufacturers of carton-
pierre in England. These beautiful works
will show to some extent to what this material
can be adopted.

There are various proportions of the
several ingredients used, some makers using
more glue than others. Some also use plaster
to make it set more quickly. The English
carton-pierre is much stronger than the
F"rench. This is due to the larger per-
centage of whiting used in the French carton-
pierre. Metal moulds are sometimes used for
stock patterns. Plaster piece moulds are
mostly used for carton-pierre, and the dough-
like mixture is hand pressed into the mould
in the following manner : — The moulds are
seasoned with linseed oil, or shellaced and oiled as required. The soft carton-pierre, or
dough, is rolled on a smooth slate or other solid slab, and is mi.xed with fine whiting, to
which a little plaster is sometimes added to give it the required consistencj-. No more
should be stiffened than can be convenientlj- used, as it may become too stift" to press easily.
Cut a small piece off, and roll on the slab to give it a smooth face, and press it into the mould with
the point of the forefinger and a small wooden tool. When this piece is firml\- and evenly pressed,
the ragged joints should be cut clean and square, then wetted with water to make a better joint for
the next piece to be laid on. Centre flowers and foliage, &c., are cast without any ground, and in
order to strengthen the several parts, thin copper wire is embedded in the weak or thin parts. Very

No. 154. — Candelabra in Cartox-Pierre.
By G. Jackson & Son, London.

396 Plastering — Plain and Decorative

thin wire is also carried across from one weak part to another, as in tying one weak tendril to the
main stem, to support it until fixed. The wire is then cut off. When the cast in the mould is all
pressed and made flush at the edges and rim, it is allowed to stand in a warm place to get firm.
Should there be any hollow places in the back of the cast, they are filled up with dry plaster or fine
sawdust to keep the cast from sinking. A board large enough to cover the mould is then placed on
the top and drawn backwards and forwards, to level the dry filling. The mould is now turned
upside down, care being taken to keep the board close to the rim of the mould. The case of the
mould is removed, and then the plaster pieces one by one. The cast is kept on the board, and
placed in a warm place until properly set. The seams caused by the joints of the mould are now
cleaned off by the use of gouge files or small tools, and afterwards sand-papered. The plaster or
sawdust on the back, to keep the hollow parts from sinking until set and cleaned up, are cleared
out, and as this material becomes very hard, it is necessary to make small holes in the stems and other
places before the cast is set, so as to admit of fine brads, screws, or needle points for the purpose of
fixing. When fixed on wood, it is usual to glue it on, and drive needle points into the cast to keep
it in its place until the glue is set. A thin paste of carton-pierre is also used for fixing it on plaster,
further supporting it by the aid of screws or fine brads. Carton-pierre casts can also be made
by pressing in jelly moulds. The following proportions are used by the best London and Paris
makers. It will be seen that some use alum. This is to prevent the dough from turning mouldy,
or having a bad smell. Some use plaster and whiting in equal proportions for stiffening, others
only whiting. The better the paper, the stronger the carton-pierre. Old ledgers, or paper made
from rags, give the best results. The paper used for wrapping oranges in makes strong work.

Recipe No. i. — 2 lbs. of best glue dissolved in 2 quarts of water, to which is added i lb. of
flour and A lb. of good paper reduced to a fine pulp by boiling and beating. The paper is weighed
dry. This mass is all boiled together for one hour, and allowed to simmer for one hour, after which
it is poured out on to a slab, and stiffened with sifted whiting. In all cases the whiting should be
dried, so as to be more easily ground fine and sifted.

\o. 2. — 2 lbs. of best town glue dissolved in 3 pints of water, \ lb. of flour, ] lb. of ground
alum, and i lb. of paper. Cut or tear the paper into small pieces, and boil for ten or twelve hours.
While hot, add the dissolved glue, also hot, then shake in the flour, alum, and \ lb. of fine sifted
whiting. Stir this mass well, pour out on to a bench, and beat it well, adding sifted whiting until it
becomes of the consistency of dough. I'ine plaster and whiting is added as required for use.
The paper should be taken out, strained, and beaten with a wooden beater, having one end studded
with lath nails, so as to reduce the paper to a fine pulp, and boiled again, and strained so as not to
retain too much water, which would weaken the glue.

London Carton-Pierre. — This recipe is used in many London shops. The following
quantities will make a 2-lb. batch: — i lb. Scotch glue, \ lb. paper, 5 pints of water, and 14 oz. of
flour. The paper used for packing oranges is usually employed for the above. It is simply torn to
shreds, and mixed and boiled with the other materials. If a small proportion of chloride of zinc is
added to the paper pulp, it will render papier-mache or carton-pierre nearly as tough as leather.

French Carton-Pierre. — 2\ lbs. of glue dissolved in 7 pints of water, f lb. of paper reduced
to a pulp. The glue is added hot to the hot pulp, and the mass boiled together, adding best French
whiting. It is then stiffened with plaster when required for pressing.

French carton-pierre was, during the last generation, greatly employed in London for internal
decoration. Bonier fils, 96 Rue Blanche, Paris (where the author was engaged for a considerable
time in the modelling and carton-pierre studios), had large commissions for the decoration of banks,

Paste Composition. ■ 397

offices, and mansions in London and the provinces. The work was made in Paris, and fixed
in England by French workmen. The designs were elaborate, but the material and fixing were
of a weak and unsatisfactory nature. Jackson & Sons, W. Cubitt & Co., Brown, the Papier-
Mache Company, and other London makers, turn out good, strong, sharp, and clean work,
and have turned their French rivals out of the field. Both carton-pierre and papicr-mach6
have been to a large extent superseded by fibrous plaster, owing to the cheapness and utility of
the latter.

Fibrous Slab or Patent Wood. — The name given to an invention patented by C. F.
Bielefeld, which consists of rolled slabs of carton-pierre. The dome, 140 feet diameter, of the
Reading-Room of the British Museum, designed by S. Smirke, R.A., 1856, is constructed internally
of this material. The sizes of the panels, composed of three pieces, are 22 feet long by 1 1 feet
6 inches wide, and were raised in their spherical form to a height of 1 10 feet, and fi.xcd in one piece
to the iron work.

P.ATE COULANTE. — Pate coulante or liquid paste is a cheap form of carton-pierre, and is
principally used for work that requires gelatine moulding, or where the work is used in positions
not exposed to much wear. It is much more quickly done than the carton-pierre previously
described, because it can be poured into the moulds in a similar manner to plaster, thus avoiding the
slow process of hand pressing. Pate coulante casts are generally made in jelly moulds.

Pate coulante is made in two different ways. The common way is to mi.x equal ]5roportions
of plaster and ground whiting with as much dissolved glue as will make the whole run freely,
adding ground alum as required. The addition of alum not only hardens the plaster, but also
hastens the setting, thus allowing the cast to be taken out of the mould more quickly. The other
method of making pate coulante is by adding a proportion of fine paper pulp to the plaster whiting
and glue. Tissue paper is the best for this purpose.

Composition. — This substance, it is said, was invented by one Liadort, a Swiss clergyman. It
has been used in France from the time of Louis XIV. in the decorations of buildings, and picture and
mirror frames. It was introduced into England about 1767 by Robert Adam. He employed it for
the decorations of ceilings, walls, chimney-pieces, doors, and window-shutters in many mansions
throughout the three kingdoms. There are numerous examples of this work, designed by Adam,
now to be seen, which for sharpness and cleanliness cannot be distinguished from wood. In point
of fact, it has withstood the test of one hundred and thirtj' years better than the stone and wood on
which it is fixed, this ornament being as perfect to-day as when it was first fixed. This material
was first made in London by Italian workmen, who jealously guarded the secret of its prepara-
tion ; but it was eventually discovered by John Jackson, the grandfather of the present firm of
G. Jackson & Sons, who was employed on some houses in Portland Place, designed by Adam,
where the Italians were decorating the interiors with composition enrichments.

It was then made and shown bj- Mr Jackson in a shop in Goodge Street, in the form of balls
strung on threads, and as small ornaments, &c. After Mr Jackson's discovery it was largelj- used in
the decorations of houses, chimney-pieces, mirror and picture frames, furniture, musical instruments,
chandeliers, public bars, and similar works, as a substitute for wood-carving. It was largely used
in Edinburgh, Glasgow, Dublin, and other towns for the decoration of wood mouldings on shop
fronts, many of which are still in existence, and the composition seems harder and in a better state
of preservation than the wood work on which it was fixed. This gives ample evidence of its
durability, even when exposed to all weathers. Granite, stone, and Portland cement having to a
great extent superseded wood facades, composition, or " paste-compo," as it is technicallj- termed, is

39^ Plastering — Plai)i and Decorative.

not so much used as formerly for exterior work. It is still in general use for decoratin;,' mirror and
picture frames, also ship saloons and capitals of iron columns, and interior wood work.

Owing to the flexible nature of paste-compo when moist, it is often used for forming mouldings
and decorations on circular work. When set, it is not so liable to be chipped as most woods. It
can be painted and gilded as required. There are various ways and quantities of materials used
for making paste-compo, each maker having a special recipe, but they all come nearly to the same
thing. The late G. Baldwin, foreman plasterer to W. Cubitt & Co., London, made this and
carton-pierre a study, and improved both materials considerably. He introduced the use of
Burgundy pitch, which dejjrives paste-comjx) of its shrinking faults, also Venice turpentine, which
has the same effect, and renders it tougher. When made, the compo batches are kept warm for u.se
by means of a pan or "steamer," having a close-fitting lid, and the bottom perforated to admit liot
steam. The batches are kept warm and pliable by covering with a piece of old blanket, or house
flannel, to retain the steam. For a small job, or where paste-compo is not often required, the
handy shop-hand can soon turn an old oil-can or pail into a steamer. This is best done by fixing a
perforated bottom about half-way down the pail, which has its bottom cither knocked out or well
perforated, or by jjlacing a small pail inside a larger one, the bottom of the small pail being well
perforated to admit the steam. An old pail without a bottom, so as to form a stand, will do for the
large or outside receptacle. The pail is placed in boiling water, care being taken that the water
does not reach the dough.

The moulds are generally made in sulphur, but some large manufacturers keep metal and
box-wood and pear-wood moulds for stock designs. Metal moulds are usually made of brass,
copper, iron, or pewter. Smith's Metal is an e.xcelicnt material for this ]5urpose. Box-wood or
pear-wood moulds require to be carved, which only a skilled carver can do, as the\' have to be cut or
sunk the reverse way to the given design.

Sl'LI'HUR Moulds. — Sulphur moulds are made by dissolving the sulphur (which is generally
sold in sticks) over a slow fire in an iron pot, continually stirring to prevent burning. When
melted, it is allowed to stand until sufficiently cool to pour on the original. The originals are
soaked in water, and treated in the same way as for wax moulding. A good guide to know when
it is fit for pouring on is to let it stand until a thin skin has formed on the top, then break the skin
at the side of the pot intended for pouring out. The mould should be taken off as soon as possible,
for being so hot, it might otherwise burn the face of the original. It also comes off easier before
contraction has taken place by the cooling of the sulphur. To make the mould stronger, so as to
resist the force of screw pressure, steel or iron filings are put in the back of the mould before it
gets cool. Old moulds, when broken up for remelting, have these steel or iron filings in them,
which fall to the bottom of the pot during the process of melting. They reijuire to be continually
stirred to keep them from forming into a solid lump, or getting too hot and setting fire to the
sulphur, as sometimes happens. Should the sulphur catch fire, remove the pot from the fire, and
cover it with an old plaster or cement bag to extinguish the flames. It only requires attention to
prevent this mishap. Burnt sul]ihur floes not run so freely, and does not take so fine an im]5ression,
as when pure.

When all the sulphur is melted, it is taken off and stirred for a few minutes, and then allowed
to cool until a skin is formed, as previously described. When the mould is full, a quantity of the
filings are taken out of the pot by means of an iron ladle (the stirring ladle), and placed in the back
of the mould. When the mould is taken off, it is bedded with Parian cement or plaster into a
wooden block, which has a sinking about J, inch larger in length, breadth, and depth than the size

Casting Composition Enrichments. 399

of the mould, the space between the mould and the wood being for the cement, to ensure a close
and firm foundation for the mould. The mould is fixed about ^ of an inch below the level of the
block, so as to protect the mould from the screw pressure. The block should have a margin of
about 3 inches all round the mould. When the mould is deep, the block is bound or clamped with
iron to strengthen it. Cast-iron cases are also used for stock designs.

Sulphur, commonly called brimstone, is a yellow brittle solid. It is not soluble in water, but
is soluble in carbon disulphate, oil of turpentine, and benzole. When heated at its lowest possible
temperature, about lOO degrees, it forms a limpid liquid of a light yellow colour ; but if this liquid
be heated to about 150 degrees, it begins to become viscid and dark coloured, it is thick and so
tenacious that it cannot be poured out of the pot. If heated still more, it regains its fluidity in part,
is still dark coloured, and finally, when it begins to boil, is converted into an amber-coloured liquid.
Sulphur is also used for moulding delicate work, such as medallions, plaques, and metal panels.

Casting Composition. — When the mould and the paste-compo are ready, the mould is
oiled with linseed oil, thinned with paraffin oil (sweet oil is a bad ground for paint), and a piece
of the compo large enough for the intended purpose is then taken up in a warm state, and rolled
about the length and width of the mould. The smoother the face of this roll, the better the cast,
and the less chance of seams or wrinkles. The roll is pressed into the mould by hand. The
compo should be about \ inch abo\e the level of the block to allow for pressure. A wet board,
about the size of the block, is placed upon the surface of the compo, and the whole is then put
under a powerful swing screw-jjress, by which the compo is pressed into ever)' ]jart of the mould.
The same pressure causes the wet board to adhere to the upper surface of the compo, so that
when the mould is taken from under the press, the board may be pulled straight up with the cast
adhering to it. There will be a ground of compo about \ inch thick, according to the amount of
pressure. The cast is cut (with a broad double-handed knife) from the ground, which is a good
guide for cutting the cast straight. The ground is then cut or peeled off the board, and put into
the steamer for the purpose of being warmed up again. The mould and the board are now ready
for another cast. It is usual to ha\e three or four boards for one mould, so that a cast can stand
to harden a little, when it is cut more easily. The casts are allowed to stand until hard, and to
allow for shrinkage before being fixed. The casts are exceedingl)- pliant and supple, and may be
bent into any form without breaking. They can be apjjlied to the round, the flat, or the hollow
with equal ease. When the casts are kept too long, and become hard, they may be made soft and
pliable by steaming, or by laying the back of the casts on hot steamed flannel. The casts are
fixed on with glue and needle points; and if the casts are soft, the backs are dipped in or brushed
with hot water, which, by softening the glue contained in the compo, forms a cementing paste that
adheres to wood, but the former way is the best. The casts require to be jointed like plaster casts,
care being taken to keep the joints as square as possible, so that there may be no hollow parts at
the joints. The joints are stopped with a piece of soft compo. If the joints are cut true and
square, and the casts well pressed up against each other, little or no stopping will be required.

The following quantities are used by different makers of repute : —

No. I. — 3 lbs. of best town glue dissolved in as much water as will just cover it, l\ lbs. of resin,
3 gills of linseed oil, \ lb. of Burgundy pitch. The glue is allowed to swell in the water for four
or five hours, and then dissolved by means of heat in a water-bath. The oil, resin, and pitch are
melted in a separate pot (taking care that it does not boil over), and when cooled, is poured into
the pot containing the melted glue, all being well stirred together. It is afterwards poured on a slab,
or clean smooth bench, on which is formed a ring of well-dried and sifted whiting. It is then well

40O Phistcritig — Plain and Decorative.

mixed up, kneaded, rolled, and beaten, until it becomes a smooth, tough, elastic kind of dough or
oil putty. Xo more whiting is used than will make a stiff dough, and divide the batch into cakes,
and put them aside until required. They are softened by steaming when required for pressing.

No. 3. — Best glue, 2.', lbs. ; resin, 2 lbs. ; linseed oil, i pint. The ingredients are melted, mixed,
and rolled until they assume the consistency of a dough, as described in Xo. i.

No. 3. — Good Scotch glue, 3 lbs. ; resin, \ lb.; linseed oil, \ pint ; boiled oil, { pint ; Burgundy
pitch, \ lb. ; \'enice turpentine, ] lb. The ingredients are mixed in the same way as in the
other recipes, the Burgundy pitch and \'enice turpentine being melted with the resin and oil.

It will be seen that the proportions are all nearly alike, being nearly i lb. of resin and i gill of
linseed oil to i lb. of glue. When Burgundy pitch is used, the quantity of resin is less, and the
quantity of oil is regulated according to the strength of the glue. The best glue only should be
used. The whiting should be well dried and ground fine, or it will lie in small dry patches in the
work, and spoil it. Gilders' London white is best. When a screw-press, with swing ball, is not at
hand, an ordinary copying-press may be utilised for small work. Some plasterers use a compo
composed mostly of glue and whiting, and a small quantity of resin, for gallery fronts, or other
places not exposed to wear and tear. This is hand pressed, but it has not nearly the same amount
of strength as the machine-pressed work.

London Composition. — The following quantities will make a 16 lb. batch. This is an old
recipe, and is mostly used in London shops. Dissolve 16 lbs. of town glue and 5 pints of water in
one pot, and dissolve 9 lbs. of ground resin and 3i pints of linseed oil in another pot. When
both are dissolved, pour the glue into the resin-pot, and stir well with a stout stick. Sprinkle in
sifted whiting until of the consistency of thin dough, and then turn the mass out on a slab, and
knead it well, adding whiting as required.

Composition for picture or glass frames is made as follows : — Dissolve 7 lbs. of best Scotch
glue in 2\ pints of water, then add 5 gills of linseed oil, 3i lbs. of resin, and \ lb. of pitch. Boil
the whole together, keep stirring until dissolved, then add as much sifted whiting as will make it
into a stiff yet pliable dough. It is then ready for pressing into the mould.

The addition to either of the above recipes of 3 oz. of coarse sugar dissolved in water to each
pound of glue will keep the material more pliable, and assists in combining better with the linseed
oil. The glue for fixing is further improved by adding li oz. of sugar and i oz. of linseed oil to
each pound of glue.

Gesscx — Gesso is a very ancient process, and like most ancient processes, is very simple. Its
remote ancestor was probably the craft of painting in " slip " clays on vases or other fictile
productions, and in this form it still survives on the commonest earthenware, and in those most
refined and beautiful works m pdte-sur-pAte,\\\\Qxzo\\ M. Solon records the art history of our time —
works which will be valued in the future as we now \alue a Greek cameo. From the use of clay
to that of chalk the transition is easy, and calcined chalk in the form of whiting was soon found to
be the best couch to receive the painted or gilded decoration of the wooden statues and pictured
panels of the earliest times, as witness the Egyptian mummy cases and other work which the
dryness of the African climate has preserved to us.

To render this whiting or "gesso " stable, it was necessary to mix some viscid liquid with it,
such as glue or size. This was soon found to be a convenient vehicle for obtaining low relief, and
thus modelling in gesso took its place amongst the decorative arts, and especially as an accessory
to the painter. The work of the early Byzantine painters illustrates this.

A visit to the Xational Gallery will demonstrate the use made of " gesso" by the early artists.

Gesso. 40'

and the ratable in Westminster Abbey affords a valuable illustration of its use as an architectural
accessory. At the Renaissance of decorative art it covered the cassoni, the larger articles of
furniture, and the panels of the wainscotting. Gesso became the general basis for the more delicate
work of that refined period, lingering on till the latter half of the last century. Sir E. Burne Jones,
Mr G. T. Robinson, and Mr Walter Crane have giv'en an impetus to the art of " gesso," which bids
fair to carry it onwards, until its modern history may rival its past. Mr Robinson says he first used
plaster instead of whiting, making use of glue and a little oil to render it fluent. This produced a
remarkably hard body, capable of being either laid on with a brush or modelled up with steel
modelling tools. When gilt, it looked like wrought metal work. It adheres so closely to glass,
marble, porcelain, or polished wood, that purposed fracture of the base on which it is laid will go
through the gesso without chipping it from the surface. Whiting is easier to work than plaster.
The beginner should use the best gilders' whiting, which is much purer than the ordinary whiting
of commerce. The glue should be of the best make, macerated in cold water until it will not
swell, and the linseed oil should be of the oldest and cleanest kind. The quantities for each varj-
according to the nature of the work proposed to be done. It is difficult to give any definite
proportions, but a few experiments will readily enable the worker to ascertain the mixture best
suited to his purpose.

Mr Walter Crane's recipe for the preparation of " gesso " is as follows : — Boil i part of
powdered resin in 4 parts of linseed oil and 6 parts melted glue, and mi.x well together. Soak
whiting in water, and add to the above mixture to make it the consistenc)- of thick cream. Mr
Robinson does not use resin, and thinks it is not at all necessarj'. It may retard absorption
of moisture of the material by the ground, but is apt to cause the work to flake off from it.
Absorption may be prevented by other means, and the gesso itself is less liable to crack when the
resin is omitted.

The mode of appl>ing the material depends upon what is wanted to be done, and what it is to
be done upon. It can be used upon any material, and if it is wood, give the surface a thin coat of
French polish if the wood is required to remain visible. If the surface is required to be covered all
over with " gesso," glue thin canvas or " skrim " over it to give it a ke\-, and rub this over with thin
glue. If on fibrous plaster, after tracing the outline, scratch well the ground to make the gesso
adhere, and stop absorption by a thin coat of shellac, or give two coats of thin glue. The work is
now ready to commence. If it is in high relief, roughly boss out the higher portions with fine tow
or cotton wool steeped in the " gesso." Wait until it is partially set, and then with a brush paint
over it, coat by coat, with fluent " gesso," until the general form is attained, using thin glue and
water whenever the absorption becomes rapid. The finishing coats and finer work should have a
little more oil added to them, so that the mixture may dry with a smooth and even surface, or it
may be finished with a modelling tool. To do this, it is well to let the work dr\- first, and soften
the surface by the application of glue water. The vessel containing the mixture should be kept
standing on a stove in another full of hot water, that the "gesso" may be kept at about the same
consistency, as if it chills it becomes "ropy," and has a tendency to flake in drying. If modelling
comes easier than brush work, the work may be commenced with a mixture thickened with
stiffened glue and more whiting, modelling with it as with cla>- or wax, care being taken not to put
it on too thickly at a time, and also to oil the finger and tools. When a high finish is required, it
ma\- be worked up with graver or small tools, polishing the surface, if required, with fine pumice-
stone or Dutch rush. Beautiful and rich effects can be produced on backgrounds by a repeated
ornament, arranged diaper-wise, and impressed b\- a stamp. The stamps may be moulded from

402 Plasteritny — Plain and Decoyative

original designs or from anj- intaglio ornament in a mixture of plaster of Paris and flour paste,
which also, when rolled out thin, forms an admirable ground for "gesso" ornamentation. This is
the "pastiglia" of the Italians, and its adaptability may be learned by examining the model of the
Villa Madama in the South Kensington Museum.

The whiting may be stained almost any colour, and by using relief of one colour and the
groundwork of another, it will produce camco-like effects. It can be gilded, lacquered, or painted
to any degree, but in the latter two cases more labour and less oil must be used in the finishing
coats.

Gesso has been de.scribed as relief painting. The gesso is mixed to about the consistency
of cream, and applied with a brush, as already stated. The brushes are composed of hog's hair and
camel's hair — fitches and pencils — using steel modelling tools for high relief The design is traced
on the surface and the gesso laid on while )-et plastic. As it dries rapid!}-, the worker must be
prompt to begin and finish the part in hand.

Ckilixg in GlCSSO. — Plate XLIV. depicts a most charming and highly artistic ceiling, in the
Saloon at Coombe Park, Sevenoaks, designed and executed by Air Walter Crane, assisted by the
late Osmund Weeks, in 1880. The following description of this ceiling is by Mr Crane : —

" The main mouldings which separate the panels (left blank in the plate) represent the
position of existing mouldings, and my work was to fill the blank panels thus spaced. The theme
of the design is a combination of the planets, and the seasons and times of da)'. The centre
circle represents the revolving wheel of the seasons, with the sun in the centre, and the signs
of the Zodiac on the rim. Two winged figures support the circle at each end of the panel, and two
fans repeat the- radiating and circular forms. In the long panels, right and left, are (right hand)
Mercury in the circle. Morning in the square below. Noon above, while Evening and Night fill
the corresponding panels on the other side, with Luna for the centre. These subjects are con-
nected and enclosed by a framework of figures typical of the hours, with globes and sickles and
hour-glasses. At each end of the central panel is a squarish panel filled by a figure of Jupiter
and Saturn respectively, enclosed in circles, with smaller figures at the corners representing their
satellites, crescent forms being afterwards adopted for these. The four panels at the corners of
the ceiling represent the planets Mars, Venus, Urania, and Neptune. These figures are about
5 feet high.

"The figure panels were all worked in gesso (or rather stucco, consisting of plaster of Paris,
size, and cotton wool) upon fibrous plaster panels with a roughish ground, supplied by Messrs
Jackson & Sons, of Rathbone Place, who also executed the casts of the repeating portions from
my models, and al.so the repeating mouldings of the framework ; but casting was only used for
the repeating portions of the work. .All the rest, both of the figure and ornamental work, was
done in the stucco direct on the panels, which were worked in the studio, and afterwards put up.

" The ceiling was coloured in tones of white and yellow metal and bronze, repeated in different
proportions in the general scheme of coloration in the room."

Pl.VSTER .VXD Ges.SO Ceiling. — As already stated, gesso is often used in combination with
fibrous plaster and in lime plaster for ceiling decoration. An example of a plaster ceiling with
gesso panels, from a design by M. Lenard, is displayed on illustration No. 155. The three panels
with figures are designed for gesso work.

Gesso Duro. — Gesso duro simply means hardened or durable plaster. Gesso is a name very
frequently misused for stucco. There are various sorts of gesso. Gesso duro is gauged with
plaster, and gesso sottile with whiting instead of plaster. Gesso grosso is specially prepared plaster.

a
o

o
o
u

Gesso Diiro.

403

The following extracts from the MS. of Cennino Cennini (a pupil of Agnoli, himself a pupil of
Giotto), written in 1437, and translated by Mrs Merrifield in 1844, will be interesting and invaluable,
as throwing light on the methods of gesso and tempera painting, dissolving glue, the use of
plaster, glue, and linen, and giving recipes iox gesso grosso &x\A gesso sottile: —

" Hozu to Begin to Paint Pictures. — In the first place, a panel of the wood of the poplar, lime,
or willow tree must be prepared, on which to paint the picture. Let it be made quite smooth.

No. 155.— Portion of a Plaster Ceiling, with Ficure Panels in Gesso, Modern.

If it be defaced with knots, or if it be greasy, you must cut it away as far as the grease extends,
for there is no other remedy. The wood must be very dry ; and if it be such a piece that you
can boil in a cauldron of clean water, after the boiling it will never split. Let us now return to
the knots, or any other defect in the smoothness of the panel. Take some glue {colia di spicchi),
and about a glassful of clean water ; melt and boil two pieces [spicchi) in a pipkin free from
grease ; then put in a porringer some sawdust and knead it into the glue ; fill up the defects

404 Plastering — Plain and Decorative.

or knots with a wooden spatula, and let them remain ; then scrape them with the point of a knife
till they are level with the rest of the panel. Examine if there be any nail or other thing that
renders the panel uneven, and knock it into the panel ; then provide some pieces of tinplate, like
qiiattrini (small pieces of mone\-), and cover over the iron w ith them ; and this is done that the
rust of the iron may not rise through the ground. The surface of the panel cannot be too
smooth. Boil some glue, made of parchment shavings, till the water be reduced to one-third of
what it was at first, and when put on the hands, if one hand stick to the other, it is sufficiently
boiled. Strain it two or three times, put half this glue into a pipkin, add a third part water, and
boil well together ; then, with a hog's-hair pencil, large and soft, pass a coat of the glue over the
panel, or foliage, or pyxes {cibori), or columns, or whatever j-ou work upon, that is to be covered
with a ground (in^essare), and let it dry; then take some of your first strong glue [colla forte),
and pass twice over your work, letting it dr}- well between each coat of glue, and it will be glued
to perfection. Do you know the effect of the first glue? A weak water or liquor is absorbed
from it by the wood, which operates exactly as if, when fasting, you eat a few comfits and drink
a glass of wine, which "gives you an appetite for dinner ; so this glue prepares the wood for the
glue and grounds to be applied afterwards.

" How to Fasten Linen on Panels. — Having thus spread the glue, get some linen cloth, old, fine
and white, and free from grease. Take your best glue, cut or tear this linen into large or small
strips, soak these in the glue and spread it with \'our hantls over the surface of the panel, remove
the seams and spread it well with the palms of the hands, and leave it to dry for two days. And
remember it is best to use glue when the weather is dry and windy. Glue is stronger in the
winter. For gilding, the weather should be damp and rainy.

"How to Lay Grounds of Gesso Grosso on the Surface of a Picture ivitli a Spatula. — Where
the panel is verj- dry, take the point of a knife like a rasp {incllo), rasp it well, and make the surface
quite even. Then take some gesso grosso, that is to sa\-, volterrano, purified and sifted like flour.
Put a porringerful on the pcrphyry slab, grind it well with this glue, as you would grind colours,
collect it, and ])ut it on the surface of the pictures, and with a \er\- smooth and rather large spatula
cover the whole surface, and wherever )-ou can use the spatula do so. Then take some of this
ground plaster {gesso), warm it, take a soft hog's-hair pencil, and give a coat on the cornices and
foliage and on the even surfaces with the spatula. Gi\e three or four coats on the other parts of
the cornices, but on the other level parts \-ou cannot use too much. Leave it to dr\- for two or
three days. Then take the iron rasp {inesclla), and level the surface ; procure some small iron
rods, which are called raffiette, such as you will find in the painters', who use several kinds of them.
Pick out all the cornices and foliage which are not flat, and w ith these make every part of the
surface of the ground smooth and free from knots.

"How to Prepare a Fine Ground {Gesso Sottile)for Pictures. — You must now prepare a plaster
for fine grounds, called gesso .sottile. This is made from the same plaster as the last, but it must be
well washed {purgatci), and kept moist in a large tub for at least a month ; stir it up well every day
until it almost rots {marcise), and is completely slaked, and it will become as soft as silk. Throw
awa\- the water, make it into cakes and let it drj', and this plaster {gesso) is sold b\- the apothecaries
to our painters. It is used for grounds for gilding, for working in relief, and other fine works.

" Hoiv to Prepare a Ground of Gesso Sottile on a Picture, and how it is to be Tempered. — Having
laid on the gesso grosso, rubbed down the surface, and polished it well and delicately, put some cakes
of the gesso sottile into a pipkin of water, and let them absorb as much as they will. Put a small
portion of it at a time on the porphyry slab, and without adding any water to it, grind it to an

Gesso Sot tile. 405

impalpable powder. Put it then on a piece of linen cloth, strong and white. When you have
ground a.s much of it as you want (for you must consider what quantity you will want that you
may neither have to make two portions of tempered plaster nor to throw away any good piaster),
take some of the same glue with which you tempered the gesso grosso. You must make sufficient
at one time to temper both kinds of gesso. The gesso sottile requires less tempering than the
gesso grosso; the reason for this is that the gesso grosso is the foundation of all your work, and
that how much soever you press the gesso grosso, a little water will still remain in it. For this
reason, make the same kind of glue for both. Take a new pipkin which is free from grease, and if
it be glazed, so much the better. Take a cake of this ge.sso sottile, and scrape it fine with a knife,
as you would cheese, and put it into the pipkin. Put some of the glue on it, and stir the gesso as
you would a paste for making fritters, smoothly and evenly, until there are no longer any lumps.
Procure a cauldron of water and make it very hot, and put into it the pipkin containing the
tempered gesso. Thus the gesso will become warm, but will not boil, for if it should boil it would
be spoiled. When it is warm, take your picture, and a large and very soft pencil of hog's bristles,
dipped in the pipkin, and taking up a proper quantity at a time, neither too much nor too little,
spread it evenly over the level surfaces, the cornices, and the foliage. It is true that in doing this
the first time \-ou should spread and rub the gesso with your fingers and hand wherever you can,
and this w ill incorporate the gesso grosso with the gesso sottile. When you have done this, begin
again and spread it with the brush, without touching it with the hand. Let it rest a little, but not
so long as to dry thoroughly ; then pass over it a third time with the brush, and let it dry as usual.
Then give it a coat on the other side, and in this manner, always keeping the gesso warm, give the
panels eight coats. Foliage and relievos require less, but you cannot put too much on cloths.
This is on account of the rasping or rubbing down, which is done afterwards.

'' Ho'lV to Begin to Smooth tlie Surface of a Panel on ivhich you have Laid a Ground of Gesso
Sottile. — When you have finished laying the ground (which must be done in one day, e\en if j-ou
work at it in the night, in order to complete it in the usual way), let it dry in the shade for two days
and nights at least. The drier it is the better. Tie some powdered charcoal in a piece of linen, and
sift it over the ground of the picture. Then, with the feather of a hen or goose, spread this black
powder equally over the ground, because the panel cannot be made too smooth, and because the
iron with which \-ou rub the picture is smooth also. When you remove it, the ground will be as
white as milk, and you will then see whether it requires more rubbing with the iron.

"How to Plane Su if aces on ivhich Gesso Sottile has been Laid, and of 'what use the Planing is. —
Take a flat raffietto, about as wide as a finger, and gently rub the surface of the cornice once ; then,
with a sharp rasp (inella arrotata), which you must hold as freely and lightly as you possibly can,
rub over the surface of the panel with a very light hand, brushing away the loose gesso with the
feather. And know that this dust is excellent for removing grease from the pages of books {carte
dc hbri). In the same manner rub smooth the cornices and foliage, and polish them as if they
were ivory. And sometimes, for you may have many kinds of work, you may polish cornices and
foliage by rubbing them with a piece of linen, first wetted and then .squeezed almost dry."

The bands of old linen evidently serve the purpose of the sand in the Egyptian method.
They afford a tooth for the plaster, and at the same time must help to hold the panel together, and
also help to prevent soap or resin rising through the gesso surface. Apparentl}-, Imen was also
used for the best coffins in Egypt in the same way. The gesso volterrano is, according to Mrs
Merrifield, plaster of Paris, w hich was obtained from some gypsum quarries in the neighbourhood of
Bologna, and Vasari gives a long account of this gesso volterrano in his life of Andrea Verrocchio,

4o6 Plastering — Plain ami Decorative.

wlio used it to make casts of dead persons. It will be noted that the gypsum for the final coating
of gesso is thoroughly slaked by keeping in water for some weeks.

A very fine example of gesso work exists in the old cathedral church at Coire. Thcj- have
there a box which the\- claim to be as old as the ninth centurj-. It is entirely covered with gesso,
on which a design in low relief has been roughly scrolled. The gesso has been polished, so as to
give the appearance of ivory. At the corners, where it has got chipped off, the ends of the linen
can be seen, which has evidently been put next the wood, as Cennino Cennini advises.

Patknt Plaster Dpxorations. — A new patent plaster has recently been introduced bj- the
Mural Decorations Company. This material has plaster as a basis, to which is added wood-wool
and fibre fabrice, the whole being treated in a peculiar method, so as to produce a hard, tough, .\ct
light substance. It is claimed that the patent was granted, because it is the only plaster decoration
with that relief, which is the ultima tliulc of the piece moulder's art. It can be easilj- fixed by
screws or nails to any surface. The designs of the stock decorations are unique and highly artistic.

D.KKORIA — Under this designation a novel specialty has been introduced by Messrs H. & A.
Hooj-donk. Plaster forms the basis o{ dakoria, which is specially prc])arcd so as to produce a hard
and tough material. It will reproduce the highest relief, with all the fine details and undercut of
carved work and chased metal.

Smith's Patent Metal. — This metal is an improvement on Spcnce's composition metal,
and is used in the construction of casts as well as moulds. Reproductions in this metal give the
most delicate lines and forms in figures and foliage. Being of a very durable nature, and not
affected by acids, lime, or damp, it has special advantages for making moulds for casting fine
concrete, Portland cement, and white cements. It is a useful substitute for sulphur for casting
composition enrichments; also for wax for casting fibrous plaster enrichments. It ma>- also be
employed in the construction of the moulds of enrichments in reverse moulds for casting fibrous
plaster cornices. Casts in this metal, taken out of moulds having a polished surface, have a glossy
or polished surface equal to the polish on the moulds. Beautiful casts, highl)- under cut, can be
produced in it from gelatine moulds. This metal is dissolved and used in a similar way as sulphur,
but iron filings are not required. Piece moulds in this metal are made as described for piece
moulding in wax.

CHAPTER XV.
SCAGLIOLA.

Historical — Artificial Marbles — Scagliola— Manufacture — Mixing — Colours and Quantities —
Polishing and Fixing— Egyptian Green— Brown Belge— Rouge Roval— Green Genoa— Vert-
Vert— Griotte— Spanish Buff— Verd Antique— Black and Gold — Verta Alps — Rome df. la
Vantz — Devonshire Red — Marezzo — Making and Polishing — Granite Finish — Granite
Plastering.

Historical. — Scagliola derives its name from the use of a great number of small pieces or splinters ;
scagliole of marble being used in the best description of this work. It is said to have been invented
in the early part of the sixteenth century by Guido Sassi, of Cari, in Lombardy, but it is more
probable that he revived an old process, and introduced a greater variety of colours in the small
pieces of marble and alabaster used to harden the surface, and better imitate real and rare marbles.
It is sometimes called viiscltia, from the many mi.xtures of colours introduced by it. The use of
coloured plaster for imitating marbles was known to the ancients, although the pure white, or
inarmoratum opus and albarum opus, mentioned by Pliny, was more used. The plastic materials
used by the Egyptians in coating the walls of their tombs partook of the nature of marble. The
ancients also used a marble-like plaster for lining the bottoms and sides of their aqueducts, which
has endured for many centuries without spoiling or cracking. In the decoration of their domes
the Moors used coloured plasters, which have stood the ravages of time. The beautiful chunam.
or plaster of India, as used by the natives, has a hard surface, takes a brilliant polish rivalling
that of real marble, and has withstood for many ages the sun and weather without sign of deca)'.
The roofs and floors of many houses in Venice are coated with smooth and polished plaster,
made at a later date, strong enough to resist the effects of wear and weather, without visible signs
of crack or flaw, and without much injury from the foot. Scagliola was largely employed by the
Florentines in some of their most elaborate works. It has been used in France with great success
for architectural embellishments, and was first introduced into this country by Mr J. \V}-att about
the middle of the last century, and was used for the columns in the Pantheon in Oxford Street.
Mr Wilson, in the Edinburgh Neiu Phil. Journal, 1S41, writes: "Plastering is now carried to
great perfection in Italy. The rooms are so finished that no additional work in the shape of
house-painting is required, the polish of the plaster and its e\enness of tint rivalling porcelain.
Scagliola is the material chiefly used. At times the surface of the plaster is fluted, or various
designs are executed in intaglio upon it in the most beautiful manner."

The walls of the grand staircase at Buckingham Palace were covered with scagliola. The
work was done in situ upon lathwork, but through the carelessness of some other class of workmen,
working overhead, who spilt some saline matter, the walls were spoilt, and had to be painted.
There is a range of columns in the Throne Room, some of which are a bright scarlet, and others
a rich blue, in imitation o^ lapis lazuli. The fluted three-quarter columns supporting the roof and
gallerj' in the Reform Club are of scagliola, worked in situ upon stone cores. The fluted three-

4o8 P/nsferiiig — Plain and Decoj'ative.

quarter columns in the drauinj^- and coffee rooms were cast in 3 feet lengths, each backed with
tiles bedded in coarse plaster. The scagliola on the walls of the staircase is \vori<ed on brickwork,
panelled, moulded, and inlaid. A church at W'ilton Wells has some fine scagliola columns, some (jf
which arc black and gold, comi^osed of Keen's cement, and worked upon stone cores, and two twisted
columns in the chancel are formed with plaster. A beautiful specimen of this work was done eighty
years ago at Whitehall, London, and is an exquisite imitation of jasper. Twenty-seven tints may
be counted in a square foot on the surface. There are some magnificent examples at the Duke
of Hamilton's Palace, near Glasgow. The walls of the hall and stairca.se of a house at Hillhead,
Glasgow, were covered with scagliola slabs equal in size to the required courses. These slabs were
cast in a bench mould, the veneer or coloured plaster being laid in first, antl then backed up \\ ith
coarse plaster, bedding in thin ])ieccs of slate to strengthen and keep them from warping. They
were cast with a groove round the edges to form a ke}' for fi.xing. The fi.xing was done by
inserting painted iron clamps into the upper edges of the slab, and screwing into horizontal wall
battens. The joints were bedded with coloured plaster as the work jjroceeded, and were finally
polished. Several houses in Charlotte Square, and other parts of Edinburgh, designed bj- the brothers
Adam, arc enriched with this work. Many of the City Guilds Halls in London are decorated with
.scagliola, notabl)' the Goldsmiths' and Fishmongers', also the Royal Exchange. St Mary's Church,
Islington, has some fine yellow antique plaster on its walls, and St Philip's, Regent Street, London,
has some .scagliola columns, made with strong timber cores to carr}' a weight. St Pancras' Church
contains some fine imitation \erd antique columns, while in a church at Grinstead, at the chancel
and altar steps, there are some of inlaid scagliola bearing inscriptions.

Octagon and round scagliola columns, in imitation of porphyrj', arc formed on stone cores at
Rab\' Castle. The walls of the hall and staircase at what was once Crockford's Club-House,
St James's, were done upon slate slabs, h inch thick, sawn on the surface with cuts about \ inch dee])
to form a key for the scagliola. The slabs were then screwed on to the walls and polished. One
of the first specimens of .scagliola was e.xecuted at Northumberland House, Charing Cross (now
the site of the Grand Hotel). The walls of the staircase were giallo antique, relieved with
Corinthian pilasters in \-erd antique and bronzed capitals. These pilasters were removed and fi.xed
in a hou.se in Hamilton Place by Messrs Bellman, Ivey, & Carter. The music gallery was formed in
porphyry. The Duke of Sutherland's town house, originally built for the Duke of York, is rich in
.scagliola. The staircase walls are in giallo antique, the architraves and fluted columns supporting
the roof are in granite, and the balustrade richly moulded in brocatello. Some slight idea may be
formed of the gorgeous splendour of this apartment by conceiving a room 50 feet square with
the walls, galleries, and columns rising with a richly coloured and highly polished .surface. All this
work was restored in 1895 b\' the same firm. .Scagliola has also been used for floors in some Lf)ndon
buildings, also at Sion House, Isleworth, " where," it is said, " a floor that had been down for seven
)-ears was taken U]j and replaced with one richly inlaid, and composed entirely of plaster." Scagliola
floors were also laid in Crewe Hall, Cheshire.

■ About si.xty years ago large quantities of scagliola wares were sold in auction rooms. Pedes-
tals for busts and statues, table tops, \ases, brackets, slabs for cabinets, caskets, found a ready sale,
until imitators of the art, combined with cheap labour and materials, brought the true scagliola into
disrepute, and finallj- drove it out of the market.

The most profitable part of the manufacture of scagliola then, as it alwav's will be, was for
the execution of work in large mas.ses. Scagliola is still in use for architectural purposes, princi-
[)ally for columns, pilasters, pedestals, wall and other surface embellishments; but the demand .is

Artificial Marbles. 409

limited, owing partly to its price, and partly to its true merits being practically unknown to man\-.
Its use is almost confined to club-houses, a few private mansions and public buildings, one of the
latter being the Albert Hall, where the columns are scagliola formed in plaster, and the Corinthian
capitals are in Keen's cement polished white. This work was done by A. Gaul (since dead), the
modelling being by the author. Recent works arc in Windsor Castle, Fulham Town Hall, City
Bank, New Travellers' Club, St Ermin's Mansions, London; Court of Justice, York; Theatre
Royal, Cheltenham ; County Council Offices, Derby ; Law Courts, Dublin. These works were all
executed by Messrs Bellman, Ivc}', & Carter, London.

Scagliola is one of the most beautiful parts of decorative plaster work, and it is regrettable that
there should not be a greater revival of such a charming and beautiful art. Its limited u.se in recent
times is greatly owing to its manufacture being restricted by rules and rigid methods and even
prejudices, and being confined to monopolists, who kept the method secret until it was looked
upon as a mystery, which greatly enhanced its cost. But through the information now at hand,
combined with a little practical experience and enterpri.se, there is no valid reason why architects
should not adopt it for second or even for third class buildings. It possesses great beauty, and is
capable of affording grand effects and the richest embellishments in architecture. Scagliola, in
skilful hands, can be produced in every variety of colour and shade, in every possible pattern, in
every conceivable form and size, from a paper weight to the superficial area of a large wall. It can
be made at a price that would enable it to take the place of the most durable material now in use.
Experience has proved that it will last as long as the house it adorns, and with an occasional
cleaning, it will always retain its polish and beauty. It has been produced in past days in our own
and other lands, and carried to such high excellence, that many of the precious marbles, such as
jasper, verd antique, porphyry, brocatello, giallo antique. Sienna, &c., have been imitated so
minutely, and with such an astonishing degree of perfection, as to dcf\' detection. It will not only
retain its polish for years, but can be renovated at a much less comparative cost than painting and
varnishing marbled wood, or plaster work. It is cheaper and more satisfactory to use scagliola in
the first instance than to go to the expense of plastering walls, columns, &c., with Keen's or other
kindred cements, used for their hardness and ready reception of paint, which are to be afterwards
marbled and varnished. Both are imitations, but painted marble can never be compared with
scagliola, which has the look, colour, touch, and polish of the more costly natural marbles.

Various Artificial Marbles. — Various patents have been taken out for the production of
artificial marbles, having for their bases plaster of Paris. These patents will be briefly mentioned
here.

Evaux's Artificial Marble is composed of plaster mixed with albumen and mineral colours,
the ground being zinc white. Rowbotham also employed plaster and albumen soaked in a solution
of tannic acid. Lilienthal makes an artificial marble with Keen's cement, slaked lime, and curdled
milk.

Pick's " Xeoplaster." — This composition was patented in 18S3, and is composed of 75
[)er cent, of plaster, mixed with felspar, marl, coke dust, and pumice-stone. Guleton and Sandeman
patented an artificial marble in 1876. It is compo.sed of Keen's cement backed with fibre, and
soaked or brushed on the back with a solution of asphalte. The slabs were made in glass moulds.
Laroque's patent marble is formed of plaster and alum gauged with gum water, the veining being
done with threads of silk dipped in the required colours. The backs of the slabs or panels are
strengthened with canvas.

Muro Marble is composed of a mixture of Keen's and Martin's cement in equal proportions,

4IO Plastering — Plain and Decorative

made into a paste, with a solution of sulpliate of iron and a small quantit)- of nitric acid in water.
The slabs are dried and tarred at a temperature of 250° F. for about twenty hours, and when cool
are rubbed, coloured, varnished, or japanned, as retiuired. There is another patent formed of
plaster gauged with a solution containing tungstate of soda, tartaric acid, bicarbonate of soda, and
tartrate of potash. Another is composed of Keen's cement 10 parts, ground glass i part,
and alum \ part, dissolved in hot water.

GUATTAKis M.VKiii.E is obtained b_\- transforming gypsum (sulphate of limei into carbonate of
lime (marble). There are two methods. The first consists in dehydrating blocks of gypsum, and
then hardening by immersion in baths containing solutions of silicate of soda, silicate of lime,
chloride of lime, sulphate of potash, soda, acid phosphate of lime, &c. The blocks are cut into
slabs or carved before being put into the bath. The .second method consists in dehydrating the
gypsum, and bathing in some of the above chemicals. They are then dried and burnt at a red
heat, and allowed to cool. After a second burning and cooling, the products are ground as for
plaster. This powder is called " marmorite." The marmorite is gauged in a trough with some of
the water from the baths as above, kneaded into a paste, and the colours added and mixed. The
paste is then put into moulds and pressed, and when set they are taken out, dried, and finally
polished. Mineral colours are used. Yellow and its tints are obtained with citrate of iron dissolved
in o.xysulphate of iron, sulphate of cadmium, chloride of yttrium, chromate of lithium, and j-ellow
of antimony. Red and its tints are obtained with dragon's blood, se.squioxicle of iron, mussaride
red, and sulphate of didymium, and the salts derived from it, which give a rose colour. Azure blue
is obtained with sulphate of sodium mixed with acetate of copper and tartaric acid and oxide of
cobalt. Green and its tints are obtained with verdigris, hydrochlorate of cobalt. Black is obtained
by pyrolignite of iron reduced by boiling in gallic acid with sirco black. Black marble is also
obtained b\- immersing gypsum blocks or slabs or the cast marmorite in a hot preparation of
bitumen. During this operation the dehydration of the material under treatment is accom])lished,
and the bitumen not only penetrates the mass, but fills up all the pores and spaces evacuated by
the water which was contained in the material treated, and a hard mass of brilliant black is
obtained in evcrj' way equal to Flanders marble. It is said that the above imitation marbles are
largely used in Florence.

C. \\'^arren, a London plasterer, and A. Gaul, a Scotch plasterer, were past masters in the art of
scagliola. The most recent makers are the Plastic Marble Company. E. Robbins patented several
improvements in the manufacture of Marezzo. Some of the above patents have been worked with
more or less success, while some ended at the Patent Office. The most prominent scagliolists
of the present day are Bellman, Ivey, & Carter, of London. This firm, under the title of Bellman &
Ivey, was formerly one of the leading firms of master plasterers in London, and did many fine
plastering works in England. These scagliola artists have no patents, but simply work on the lines
herein set forth, and their works stand unrivalled for general superiority and artistic finish.

Scagliola Manufacture. — Scagliola can be made in situ or in the workshop, according
to the requirements of the work ; but in either case it is necessary that the workplace should be
kept at a warm temperature, and the work protected from dust or damp atmosphere. The plaster
should be the strongest and finest in quality, and free from saline impurities. It should be well
sifted to free it from lumps or coarse grains, which otherwise would appear as small specks of white
in the midst of the dark colours when the polishing is completed. Glue water should be made in
small quantities, or as much as will suffice for the day, as it deteriorates if kept too long. Glue
tends to harden the plaster, and gives gloss to the surface. Unfortunately it is also the cause of its

Making Scagliola. 411

subsequent dulness and deca>' when exposed to moisture and damp air, hence the necessity of
using the best glue, good and fresh glue water. If scagliola is required to be done in situ on brick
walls, the joints should be well raked out and the walls well wetted. This gives a good key, stops
the excessive absorption, and partly prevents the evil effects of saline matters, that are found in
most kinds of new bricks. These saline matters are the principal cause of subsequent efflorescence
which sometimes appears on plastic surfaces, and is so unsightly and disastrous to surface
decorations. Saline matters are also caused by acids, used in the manufacture of some cements.
Saline is also found in mortars made with sea water, or with unwashed sea sand. These impurities
can be avoided by careful selection, mixing, and working of the materials. Brick walls for scagliola
should be allowed to stand as long as possible, and wetted at intervals. This allows more time for
the saline to e.xude and be washed off. The exudation may be hastened or the salts ab-sorbed and
killed by brushing the walls with a solution of freshly slaked hot lime. This is allowed to stand
until dr}-, and then cleaned off b)' scrubbing with warm water and a coarse broom. If space
permits, a wall battened and lathed is the best preventive. Scagliola slabs, screwed to plugs or
battens, are protected from saline and internal damp.

Iron columns to support overhead weights, and fixed as the building proceeds, are often
covered with scagliola. If the work is done iti situ, the iron core is surrounded with a wood
skeleton and strong laths, or painted wire lathing. Two wood templates are cut, equal to the
lower and upper diameters of the columns, and one fixed at the top and bottom of the shaft. The
groundwork is then ruled fair with a diminished floating rule. This gives a guide and equal
thickness for the "scag" (the trade abbreviation for scagliola stuff).

The floating coat is composed of the best and strongest plaster procurable, and gauged as stiff
as possible with sufficient strong size water, so that it will take from twelve to twenty hours to set.
The floating is general!)- brought out from the lath in one coat. A tenth part of well-washed hair
is sometimes mi.xed with the gauged plaster, to give greater toughness and tenacitj-. The surface
must be carefully scratched with a single-pointed lath, to give a sound and regular key for the scag,
which is laid on in slices, and pressed and beaten with a stiffish, square-pointed gauging trowel,
somewhat like a margin trowel. The scag is laid about i inch fuller than the true outline, and
when set, the surface is worked down with a " toothed plane." This plane is similar to that used by
cabinetmakers for veneering purposes. The irons are toothed in various degrees of fineness, and set
at an angle of 70'. If the columns are fluted, a half-round plane is required for the flutes. As the
planing proceeds, the outline is tested at intervals with a rule, as a mason does in using a straight-
edge when working mouldings. A planed or chisel-cut surface shows up the grain and figure of the
marble much better than if ruled. A rule is apt to work out or otherwise spoil the figure of most
marbles. The beating on the slices may disturb the figure of the marble at the outer surface, but if
the scag is gauged stiff, the inner portion will be intact, hence the advantage of planing. To obtain
greater cohesion between the scag and the floating, the latter is brushed with soft gauged stuff just
before each piece of the former is laid. The scratching is also filled up at the same time, so as to
obtain the full power of the ke\- with the least amount of pressing on and beating the scag slices
in position. When the shaft is planed, the wood collars are taken off ; then the ba.se and necking
moulding, which have been previousl)- cast, are screwed in position, using plaster (coloured the same
as the ground of the marble) for the joints. When dr\-, the whole is stoned and polished. Pilasters
or other surface work done i)i situ are executed by similar processes. Cast and turned work should
always be supported bj- strong wooden frames, formed with ribs, and co%-ered with \ inch to i inch
thick sawn laths. The strength of the frames is regulated according to the position and purpose

412 Plastering — Plain and Decorative.

of the intended work. For example, a column w ith base placed on a square pedestal would not
require so strong framing as the pedestal which has to support the column and base ; also, being on
the floor level, it is more exposed to contact and possible pressure. Framing is also necessary for
fixing purposes, and to allow for the work being handled freely when being moved from the
workshop to the building, and when being fixed. Small work may be made without framing.
Turned columns are framed in two different methods, each wa>' being for a special purpose. If it
is an " independent column," or in other words a completed column, not intended to surround a
brick or iron core, the frame is made strong and in one piece. If a " case column," which is intended
to surround a brick or iron core, the frame is made lighter and thinner, and in such a way as to
admit the column to be cut cither in two equal parts, or with one-third out, or just as much as will
allow the larger part to pass over the iron core. Care must be taken that the inner diameter of the
skeleton frame is greater than the diameter of the iron core. This is to allow for fixing. The outer
diameter of the frame is made about i inch less than the finished outline of column, to allow \ inch
for the core and \ inch for the scag. The two parts of the frame are fixed with wood pegs (not
nails), so that they may be sawn when the column is cut into halves. This is not done until the
column is polished and ready for fixing. The parts are best separated by cutting with a thin and
fine-toothed saw. The thinner the cut, the better the joint. The two parts are fixed on the iron core
with brass screws or clamps, from 3 to 4 feet apart, and the joints made good with coloured plaster
as before. Sometimes a zigzag joint is made, the one side fitting the other, to give the marble or
figure a more irregular and natural appearance. The joints are then stopped with various tints,
these being the same gauge as used for the face.

Sometimes the framing is made longer than the shaft, so as to project at each end. These
projecting parts are used as fixing points for screws, and binding round with hoop-iron before the
plinth and cap are fixed. These parts protect the edges of the work while being moved and fixed.
Considerable skill and patience is required to make a strong joint, well polished, and imperceptible
to the eye. The frames are made with solid ends, with a square hole in each to fit the spindle.
The .solid ends are cut out of inch deal, and are used to keep the skeleton firm and in a central
position when the spindle is turning on the bearings. One of the ends is fixed to the flange of the
spindle with screws. If a case column is being made, the solid ends are taken off before the column
is cut ; but they form permanent parts of the framing for an independent column. The mould is
fixed at one side, and level with the centre of the spindle, which is the centre of the column's
diameter. Care must be taken that the profile of the mould plate to the centre of the spindle is
one-half of the required diameter at each end of the shaft. Vases are generally made without wood
framing. They are turned on a spindle with a plaster core screwed to the flange in the form of a
parabola, to give the form of the hollow inside. On the core a coat of scag is laid and allowed to
set. This is scratched to give a key for the coarse plaster which forms the body of the vase. This is
formed to the desired outer profile by means of a mould fi.xed on the outside, and muffled to allow
for a thickness of outside scag. When the core is run, the muffle is taken off, and the scag laid,
keeping it about \ inch thicker than the true profile, to allow for turning and stoning. When the
scag is set, it is turned, and then the vase is taken off the spindle and plaster core. The spindle hole
is u.sed as a key for a slate or iron dowel for fixing the vase on to the square plinth. The vase is
then polished. Cheap work is usually run or turned \\ith a mould. This is done to save turning
with chisels, but it spoils the true figure of most marbles.

A more recent way of imitating marbles is known by the name of Marezzo, which does not
require so much polishing, being made on plate glass or other smooth surface. Keen's superfine

Mixing Colours for Scagliola. 413

plaster is used. The mode of making Marezzo is described later on. Specimens of the real marbles,
to give the colour and form of veining, spots, and figures, will be of great .service to the beginner.

Mixing.— Mixing the colours is an important part of .scagliola manufacture, and the following
colours, mi.xing, and mode of using, will .serve as an index for the imitating of any other marble
that is not detailed :— Fine plaster fnot cement) is used for making the best class of .scagliola,
gauged with size water, which is made by dissolving i lb. of best Scotch glue with 7 quarts of water.
(This is known in the trade as " strong water."j The stuff, when gauged, will take about six hours
to set. All mixing is done on a clean marble or slate slab. One of the principal arts is the mixing,
but there are no two men who mix exactly alike, and it is largely a matter of experience. The
chopping or cutting into slices with a knife is another important point in the mixing, apart of
course from the special colours. Where there are two shades of one colour in any given work, the
cutting does not affect their original shades. No dry colour is used, only ground water-colours.
The beginner had better experiment with a small sample of" Penzatti " or Penzance marble. With
I gill of size water, gauge plaster middling stiff, then mix thoroughly with the gauged plaster a little
red. Do the same with a little black. (See quantities below.) Blend this stuff properly b_v
working it on the bench with the hands (not tools), then roll it out, and cut it into slices about
I inch thick. Take up these slices, and part them with the fingers about the size of a walnut, and
put them aside, a little distance apart, on a bench.

The veining in this instance is white. Over these little lumps scatter half a handful of crumbs,
made by reserving a little of the gauged plaster, and making it crumbly with dry plaster, mixing
with it a few small bits of alabaster or marble. Then gauge a little plaster in a basin, and with a
tool brush, about 2 inches wide, dip into this gauged plaster, and smudge the little lumps all over
with it. Knock these lumps together into a big one, and chop the big lump three times. (This
chopping means cutting with a knife into slices once, and knocking up again ; cutting with a kinTe a
second time, and knocking up again ; and then cutting with a knife a third time, when it is finished. 1
This lump is then read)- to be cut up into slices, and applied to any [purpose required ; but in this
case, being wanted for a specimen, it is cut into slices about A inch thick, and laid close together
flat on a sheet of paper, and allowed to remain until set. It is then jslaned, and when Axy polished.
This operation is an embodiment of the principle of " scag " mi.xing nearlj- from beginning to end,
onl\- submitting one colour for another for the various marbles. The mixing is generally known
as plain and rich, and may be described thus : — Take a Sienna pedestal, for instance. Two shades
of sienna, plain mi.xing ; one or two shades of dark with veining, rich mixing, both done on the
.same principle as Penzatti. They are cut into slices and laid on alternately. All veining of any
colour is done as described above, only modified b\- the consideration that if strong \eining is
wanted the stuff must be stiffish, and for fine veining it must be slightly softer. Various-sized
measures for the water and scales for weighing the colour should be used. Pats of each gauge
.should be set aside as test pats to determine when the main portion of stuff is set. It is advisable
to number the pats for future reference as to quantity of colours, time of setting, and tints when
dr\-. The various colours and tints are gauged and chopped as previously described, and according
to the marble required. The core being laid on the skeleton, and left in a ke)-ed and rough state
until dr\- and expansion ceased, it is ready when set for the scag. The core is now damped
and well brushed with the white or other vein that has to be made. The veining is gauged thin,
and being brushed and laid in the core, will tend to make the slices adhere better, and fill up the
interstices caused by the jagged edges of the cut slices. The slices are then taken and pressed
firmly on to the core, arranging in proportion to the figure of the marble. To render the work

414 Plastering — Plain and Decorative.

more dense, beat it with a flat-faced mallet antl a lari^c i,faut,nns,^ trowel with a square end. Try the
work with a rule to sec if the surface is fair. The rout^h surface should not be less than \ inch
thicker than the true line of the work, to allow for planing and stoning. When required, pieces of
alabaster are inserted before the stuff is set. Metallic ores are used in some marbles, also pieces of
granite and real marble. When the .scag is laid, the work is left until set and dry. It is then
planed, stopped, stoned, and polished. Columns and circular work arc turned on a lathe, and the
rough surface reduced to the true profile with long chisels similar to those for turning wood or other
materials. This should not be attempted until the materials are thoroughly set.

Colours .\NI) Quantities. — The following are the colours and quantities used for various
marbles. The proportions of strong water are as near as can be given, but as the strength of glue
from which the strong water is made varies, the due quantity should be tested by gauging small
pats of plaster to ascertain the time of .setting. As the tints of real marble vary in some species,
the mixing must to .some extent be left to the ingenuity of the workman. With a little practice
and perseverance, a careful and observant man will soon succeed in getting the required tints.

Penzance Marble. — lo oz. of light purple brown to i pint. Veining (plain mixing), 2 oz.
black to I gill ; veining (rich mixing), 5 oz. black to i pint ; veining ("rich mixing), i oz. black
to A gill. All liquid measurements refer to strong water.

K(;vi'TlAN Green. — 5 oz. black to i pint. Veining, \ oz. green to I pint (light .shade) ;
veining, \ oz. green to ?, gill. White the same, black chopped three times ; a few black spots
same as brown Beige.

Brown Belge. — Four shades — i light purple brown (indigo) ; 2 middle shades (blue black) ;

1 very dark shade (vegetable black). Veining, burnt sienna with red alabaster spots — 4 oz. (light
shade) to i pint ; 4 oz. (middle) to \ ]jint ; 4 oz. (very dark) to \ pint ; i oz. burnt sienna to
\ pint ; \ oz. black to \ pint ; A pint for the grey, with crumbs, and red alabaster spots.

RoucE RoY.VL. — Colour, light purple brown, with a little sienna, and umber, with ultra-
marine, blue or blue black.

Dark Pori'IIVRV. — Colour, light purple brown, with black, and a little ultramarine, blue
spots, black, vermilion, grey, and a little red.

Green Genoa. — 2i oz. green to \ pint (rich mixing) ; 5 oz. black to i pint. Veining, \ oz.
green to j pint. White veining the same, with alabaster spots, and black.

Vert-Vert. — \ oz. green to \ pint ; dark green with sienna ; dr\- green plaster.

Devonshire Red Marble. — All sienna work. Light Mixing — i shade grey; i shade
lemon chrome ; i shade light purple brown ; i shade flesh colour. Veining, burnt sienna. Dark
Mixing — I shade light purple brown, with indigo blue in it ; i shade dark purple brown ; i shade
middling purple brown ; i shade grey ; i shade lemon chrome. Veining, burnt sienna, with small
alabaster spots.

SlENN.v Mixing. — 5 oz. sienna to \ pint, dark shade ; 3 oz. sienna to A pint, middle shade;

2 oz. sienna to \ pint, light shade.

Griotte Marble. — 10 oz. of light purple brown to i pint ; 5 oz. of dark purple brown to
i pint, with alabaster spots and crumbs, with dry black. Veining, black ; very stiff.

SlWNISH Buff. — Burnt sienna, 2 shades, with large alabaster spots. Veining, white and blue
black, with small alabaster spots. Ground with red veins, and small spots.

Light Veru Antique.— 2i oz. green to ', pint ; li oz. black to i gill ; A gill black to i gill
grey shade.

Dark Verd .Antique. — Green spots cut ; grey spots cut ; black spots with green and grey.

Polishing Scagliola. 415

Veining, 2i oz. green to I pint rrich mixing) ; 2i oz. dark green to J pint (rich mixing, ; \ oz.
black to \ pint (rich mixing).

Plain mixing, same as above, with small alabaster spots, and small black spots.

Black and Gold. — 5 oz. of black to i pint. Veining, 2 shades burnt sienna to \ pint ("rich
mixing) ; 2 shades dark sienna to i pint (rich mixing) ; 2 .shades light to \ pint (rich mixing; ;
2 parts light and grey, with alabaster spots, and crumb.s. Veining must be stiff; 3 oz. of black
to I gill.

Walnut. — 2 parts burnt umber ; i part rose pink.

Verta Alp.s Marble.— 5 oz. black to i pint. Veining, \\ oz. of green to li gills; \ oz.
green to i gill, with black crumbs chopped three times for the ground.

Ros.SE DE LA Vantz Marble.— Rich mixing with indigo blue— i shade light purple brown;
I shade dark purple brown ; i shade Venetian red. Veining, black for the ground, and white and
green veining for the mixing, with alabaster spots, and crumbs.

POLLSHING White Scagliola. — White scagliola is often made with superfine Keen's cement.
A small portion of mineral green or ultramarine blue is added to improve and indurate the white
colour. White work requires special care to prevent discoloration or specks. W'hen the work is
left for drying purposes, or at the end of the day, it should be covered up with clean cotton cloths
to prevent the ingress of dust, smoke, or being touched with dirty hands. The tools should be
bright and clean. Steel tools should be as sparingly used as possible. When the cement has
thoroughly set, and the work is hard, it is first rubbed down with pumice-stone, or finely grained
grit-stone, by the aid of a sponge and clean water, rubbing lightly and evenly until the surface
is perfectly true. It is then stoned with snake-stone (Water of Ayr), using the sponge freeh' and
the water sparingly until all the scratches disappear. Afterwards well sponge the surface until free
from glut and moisture. It is now ready for the first stopping. Stopping is an important part
of the polishing process, and should be carefully and well done, to ensure a good, .sound, and
durable polish.

First gauge a sufficient quantity of cement and clean water in a clean earthenware gauge-pot.
The gauged stuff should be about the consistenc}' of thick cream. It is well dubbed in, and
brushed into and over the surface, taking care that no holes or blubs are left. When the stuff on
the face gets a little stiff, scrape off the superfluous stopping with a hardwood scraper having a
sharp edge. Then repeat the brushing (but not the dubbing) with the soft gauged stuff, and
scraping two or three times, or until the surface is solid and sound. The work is now left until the
cement is perfectly set. It is then stoned again for the third time with a piece of fine snake-stone,
or Water of Ayr stone, and stopped as before, with the exception that the superfluous stopping is
not scraped off, but wiped off with .soft clean rags. The work is left until the cement is set and the
surface dry. It is then polished with putty powder (oxide of tin), which is rubbed over the surface
with soft clean white rags, damped with clean water. In polishing mouldings, the stones must
be cut or filed to fit each separate member of the moulding.

Polishing Scagliola. — The jwlishing of scagliola is slightly different. It is first rubbed
down with a soft seconds (marble grit) or gritty stone (say Hare Hill stone), using the sponge and
water freely until the surface is true. The grit and glut are cleaned off with a brush and sponge,
using plenty of clean water, until the pores are free from grit. The moisture is sponged off, and
the work left until sufificiently dr\-. It is then stopped in the same manner as white work, but
using stiff stopping for large holes and steel scrapers instead of wood. The stopping is made
with the same kind of plaster, size water, and colour as was used for the ground colour of the

4i6 Plastering — Plain and Decorative.

marble that is being imitated. The stopping and stoning are repeated as before, and it is finally
polished with puttj- powder, using pure linseed oil instead of water. The repeated operations of
stopping and stoning must not be proceeded with until the previous stopping is perfectly set, and
the work dr>'. A small portion of spirits of turpentine is sometimes added to the gauged coloured
stuff to facilitate the drying. The work between each combined stopping and stoning will take
from one to five daj-s to dry, according to the size and thickness of the work and the state of the
atmosphere. Never dry the work b\- heat. The thorough drj^ness and hardness of the work are
most essential before proceeding to polish with the putty powder and linseed oil, because any
contained damp will work out and spoil the polish. Work not perfectly dry may take a high
polish, but it will soon go off when the damp comes through. Columns or large hollow work are
not so liable to be affected b\- the damp, as it ma\- escape through the back ; but there must be
some opening or %-entilation to allow it to finally escape.

If the polishing is well and carefully done, the polish produced on scagliola will equal, if not
surpass, that on real marble. Tri])oli polishing stone, sometimes called alalia, is a kind of chalk
of a yellowish-grey colour. Water of Ayr stone is also used for ]Jolishing. In large work a
rubber of felt dipped in putty powder may be used. Salad oil is sometimes used for finishing.
Linseed oil makes the hardest finish, and dries quicker.

IVIari'.ZZO. — Marczzo artificial marble manufactured from plaster or Keen's cement and
mineral colouring matter is made in wood or plaster moulds for moulded work and on slate
or glass benches if in slabs. If thick plate glass is used, the worker has the advantage of
being able to look through it to see if the figure of the work requires altering. Glass also
has the advantage of lea\ing a smoother and more polished face. All wood and plaster moulds
should be got u]) with a good face, and proiJcrK- seasoned, to save stoning and polishing the face of
the work. Keen's cement may be used advantageouslj- in making Alarezzo, especiallj- for chimney
pieces, or other works required for exposed positions. Keen's cement for Marezzo should be of the
highest class. If the cement is not of the best, it will effloresce, rendering the work of polishing
difficult, if not spoiling it altogether. Keen's cement requires no size water, but in gauging either
Keen's or plaster, no more should be gauged than can be conveniently used. The quantities of
colours. Keen's cement, plaster, and size water should be measured, and gauged pats kept for
future reference. All gauge-pots should be of earthenware, as thej' are more easil)- cleaned out, and
do not rust, as is the case with metal pots. All the tools should be kept bright and clean, as when
working scagliola.

Marezzo is made in the reverse way to scagliola, as the face or marble is put in the mould first,
and the core or backing put on afterwards.

All the mineral colours should be of good quality, in fine powder, and ground in water, known
as " pulp." A number of basins should be handy, and there should be a supply of fine twist silk in
skeins varying in diameter from | to ;^ of an inch, and cut into lengths of 14 to 18 inches. For
common work, good long flax fibre may be used. Canvas is also required. One end of the silk or
fibre skein must be knotted. These are known as " drop threads."

After the moulds are made, seasoned, and oiled, the young hand may begin by tr>'ing to make
some easy marble, .say " St Ann's," for a slab or chimney-piece. Gauge Keen's extra superfine
cement or superfine jjlaster, in a large [basin labelled No. i,.well mixing it until about the consist-
ency of cream. This is pure white. Now pour a small quantity of this white pulp into two
small gauge-pots, Nos. 3 and 4. Pour a third of what remains in the No. i pot into another gauge
pot. No. 2. Take some black-coloured pulp, and make No. i a blackish-grey. Colour in the same

Making Marezzo Marble. 417

way Xo. 2, onh- very much blacker than Xo. i. Xo. 3 is now slightly tinted with pulp from Xo. i.
This leaves Xo. 4 pure white. Then take a skein of twist (or threads), dip into Xo. 4, the pure
white, and well charge it by stirring it about with the fingers ; take out the threads, taking each end
between the thumb and forefinger of each hand, and with the remaining fingers of each hand sepa-
rate the threads, allowing plenty of " swag," and strike this into the face of the mould, making each
stroke at different angles, recharging the threads when necessary. Repeat this process with pulp
from Xo. 3, but in a lesser quantity ; then dip your finger ends into No. 2, and fling drops about
the size of large peas all over the veining. These drops must be thrown on with considerable
force, so as to cut into the veins as much as possible. Dip the fingers into Xo. i, and throw on
with a considerable degree of force larger drops, and more thickly. Repeat this process again with
Xo. 2, using alternately from each gauge-pot until you get a uniform thickness of surface ("scag"),
about \ inch in thickness. Now run a trowel over this to lay down any ridges. Cover the work
with a piece of canvas, laying it evenly, smoothly, and without wrinkles. Be careful to put the
canvas in the proper place, as moving it would spoil the lines of veining ; then spread a quantity
of dry coarse Keen's lightly over the entire surface. This will absorb any superfluous mois-
ture through the canvas. After the canvas and coarse Keen's have lain from ten to twenty
minutes, or according to the stiffness of the gauge of the marble, the canvas and coarse cement
are carefully lifted off. Should any portion of the face of the scag leave the mould, and adhere to
the canvas, it is taken off and put back in its place in the mould. The whole surface is now
trowelled to render it dense and hard. The moisture should be .sufficiently absorbed, or the
trowelling may spoil the figure. The proper absorption of the moisture by the dry cement through
the canvas, and well trowelling, are most essential to good work, ensuring hardness and density.

The core or backing is now made by using the coarse Keen's previously used for absorbing
the moisture from the face, gauging it with some fresh coarse Keen's as stiff as possible. This is
laid on as thick as required. If the face of the scag should be very dry, spread a little thin coarse
gauged Keen's, so as to give a perfect cohesion between the marble and the backing. The flat
surface of the backing should always be ruled or floated straight with a uniform thickness, so as to
give a true bed for the cast when it is taken out of the mould, and laid on a bench ready for
stoning, stopping, and polishing. This can be done as soon as it is thoroughly set and hard, and in
the same manner as scagliola.

Marbles having long stringy veins require a different method of putting in the veins. Take the
skeins, or " threads," by the knot with one hand, and thoroughly saturate them with the veining
mixture, and run the finger and thumb of the other hand down the threads to clear them of any
excess of veining colour with which they may be charged. Then give the end not knotted to your
partner, holding the knot in your left hand. Pull the threads asunder, so as to take the form of
the veins of the marble you are copying, then lay them in the mould, leaving the knots hanging
over the edge of the mould, or at least visible, to facilitate their removal when required. The
threads should be arranged on the mould so as to take the form of the veining. The other coloured
materials are then thrown upon the thread veins, which quickly absorb the colouring matter from
them ; care being taken that the various colours are thrown or dropped from the finger tips, to form the
figure of the body of the marble that is being copied. When the mould is sufficiently and properly
covered with the marbling, take hold of the knots and withdraw the threads. These should be
cleaned by passing down the finger and thumb for future use, saving the superfluous stuff for filling
up any holes in the marbling. The absorption by the use of canvas and dry coarse Keen's, and
the filling in of the backing or core, is then proceeded with as before described.

4i8 Plastering — Plain ami Decorative.

Granites, porphj-ries, &c., are made in a different manner. For |jorphyries with white and
black specks, make a slab of white Keen's about J inch thick, and another in black, the same
thickness. When they are set and hard, chop them into small pieces, then run them through a
sieve, having a mesh to let through the pieces of the required size only. The pieces retained in the
sieve can be broken and sieved again. The whole is now sieved again through a smaller mesh,
which retains only the size wanted. The refuse can be used for small work or backing ujx When
the gauged stuff for the facing is mixed of the required tint (a reddish-brown), damp the black and
white specks, so that the moisture be not absorbed when mixed. Then mix the black and white
s]jecks with the gauged colour b)- means of a trowel and rolling, care being taken not to break the
edges and faces of the black and white specks. When it is w ell mixed, laj- it on to the face of the
mould about /^ inch thick, pressing it as firmly and ev-enly as possible. Then absorb the moisture
by means of canvas and drj- coarse Keen's ; trowel it well to give density, and fill in the backing or
core as before. For "Rouge Royal," "Verd Antique," &c., requiring large white patches of
irregular size, the sieving can be dispensed with. The white pieces are broken haphazard, and
pieces of alabaster can also be inserted in these, and many other marbles, due regard being given
to the size and quantity, so as not to produce an unnatural effect. The remainder of the figure is
formed with the "drop thread.s," and the other colours being thrown on.

From this description of Marezzo, the workman will understand that in the case of marbles
classed as " Breccias," such as " Rouge Royal," " Black and Gold," &c., having patches and rough
jagged veins in them, he must have flat pieces of the required colour previousl)- made and broken
up, or alabaster, as the case may be, inserted into them, and the veining done with the " drop
threads," and that fine or long veining threads are not required ; that unicoloured marbles require
no veining threads ; that the long veined marbles require the long threads, and in some cases the
" drop threads " as well, and that granites, porphyries, &c., require no threads ; that black is
difficult to make owing to the pure white cement requiring so much colour ; and finally, that in all
cases, whether Marezzo or scagliola, the polishing is done in a similar manner, whether using
plaster or Keen's cement.

The details given must be carefuUj- followed to produce work artistic in figure and appearance.
The directions for making " St Ann's," so far as manipulation is concerned, apply to all others. A
little patience, practice, and perseverance will soon give confidence and expertness in producing
sound scagliola and Marezzo.

Granite Finish. — Granite finish is a peculifir finishing coat of plaster, which is sometimes
used in some districts of America to imitate granite. For granite finish, first render the walls with
hydraulic lime, and when nearl>- dr>- laj- with a thin coat of the same material but coloured light
brown. Then while this coat is still moist splash the surface lightl}- with white stuff, then with
black stuff, using onl>' half as much as used for the white splashing, and finish by splashing w^ith
red stuff, using as much as used for the white stuff. The red stuff is best applied by dotting the
surface with a small brush charged with the coloured stuff. After these coloured lime stuffs are
firm, but not set, the surface is carefully trowelled, using the minimum of water so as not to mix the
various coloured stuffs. The surface is sometimes left in a rough state, or as left when splashed,
After the surface is firm, it is set out and jointed to represent blocks of granite.

Gk.\nite Plastering. — Granite plastering is a method, introduced by the author, to imitate
granite. This mode of imitating granite is based on the scagliola process. It is also somewhat
similar to the granite finish, and gives better and more reliable results. The method of executing
granite plaster work is as follows :— First select the most suitable lime or cement for the situation.

Granite Plastering. 419

such as Portland cement or hydraulic lime for exterior work, and Parian or other white cement
for interior work. Having decided on the material, gauge three different coloured batches, one white,
one red, and one black, taking care that the stuff" is gauged stiff" and expeditiously so as to obtain a
hard substance. The material is coloured to the desired shades, as described for scaglioia or
coloured stuccos. When gauged, the stuff"s are laid separately on a bench and rolled until about VV
inch thick, and when nearly set they are cut into small irregular cubes and allowed to set and harden.
The wall is then floated, ruled fair, and the surface keyed, and when set it is laid with a thin
bedding coat of similar stuff" used for the floating, but coloured light brown. The coloured cubes
are then mixed together in due proportions, and gauged with a portion of the light brown coloured
stuff and laid on the thin coat while it is still soft. The whole is then firmly pressed with a hand-
float until a close, compact, and straight surface is obtained, taking care when pressing the stuff" not
to break the cubes. After the stuff" is set, and perfectly dry and hard, the surface is rubbed down
and polished, as described for scaglioia or for marble plaster. The bedding coat should be
sufficiently thick to receive the coloured cubes, otherwise the larger cubes will project at parts, and
cause extra labour in making a uniform and straight surface. Unless the cubes are fairly level
when pressed, the surface will have a spotty appearance, besides being more difficult to polish.
Where expense or time is a consideration, a striking appearance is obtained at less cost than polished
work, b)- simply finishing the surface with a cross-grained hand-float, and a semi-polished surface is
obtained b}- trowelling, or by scraping the surface with a joint-rule. Grey or light-coloured granites
are imitated by altering the colours of the cubes and the bedding coat as desired. Bold and
striking effects on wall surfaces can be obtained by a combination of different coloured granites,
laid out in bands and borders. The effect can be increased by the introduction of borders in
sgraffito, with the bands in granite plaster.

CHAPTER XVI.

FOREIGN PLASTER WORK.

Introductory — Saracknic — Persian — Spanish and Moorish— Indian (One-Coat, Two-Coat, and
Three-Coat Work)— Chinese— Italian— Italian Stucco— French— Carved Plaster— German-
German Mortar— Austrian— Belgian— Russian.

Introductory. — The heading of this chapter may perhaps need a few words of explanation,
seeing that the plaster work of Italy and France, named above, has been treated of and
illustrated in the Introductory Chapter written by Mr G. T. Robinson. It should, therefore, be
explained that whereas in that chapter all work is dealt with from the historical point of view, in
the present — although some historical notes will be found — the main intention is to gi\e an account
of the craft as it has been, and is now practised, in the various countries brought under consideration.

S.\RACENIC Pl.vstek W'ork. — Saracenic or Arabian architecture dates from the time of
Mohammed in the seventh centur>-. Saracen, which simjily means Eastern, was the universal desig-
nation of Moslems in the Middle Ages, the word conveying the two ideas of oriental and mediaeval.
Saracenic architecture spread to Syria, with Damascus for its centre. Another form of it is .seen in
Morocco, Persia, .Armenia, and even Turkey in Europe. This architecture is distinguished by the
form of arch know 11 as the " horse-shoe," which is supposed to be an invention of the Eastern
Christians.

The Mohammedan law placed stringent limits upon the form of ornament to be used in the
endless designs for mosaic, marquetry, or stucco work. There must be no image of any living
thing, vegetable or animal. Naturally these imperious limitations conduced to the formation of a
unique style of decoration, vegetable forms being e.xcluded for the first time. Mere curves and
angles or interlacings had to bear the chief burden of a design, but this was distinguished by a
lavish variety of colour. The lines, curves, and angles gradually developed into a characteristic
species of tracery or interlaced strap-work, very agreeably diversified by the ornamental introduc-
tion of inscriptions. The gorgeous domes and minarets, and the decoration of their surfaces with
ingeniously complicated and geometrical figures cut in stone, plaster, or wood, the whole being
beautifully coloured and gilded, are also distinctive features. The mosque at Medina, built in
A.n. 622, had partitions constructed with wattles and pla.ster. The Mosque of Ibn-Tulun, Cairo,
was begun in A.H. 263, and finished in A.D. 878. The court in this mosque is surrounded on all four
sides by arcades of painted arches resting on plastered brick piers. The capitals, like the rest of the
building, are plastered and enriched with buds and flowers. The spaces between the arches are
partly filled in with windows and engaged columns. The surfaces are enriched with a series of
plaster rosettes worked by hand, and the inner parts with a knop and flower pattern. Illustration
No. 156 depicts these arcades. It will be seen that portions of the wall plaster are broken, but the
whole is in fair preservation, considering it has been exposed for a thousand years.

Saracenic Plaster JVork.

421

The decorative borders in the Mosque of Ibn-Tulun are the earliest examples that have been
found of the geometrical designs and scroll work which are so characteristic of Saracenic ornament.
With the exception of the grilles and the fountains, the entire mosque is built of burnt brick,
plastered on both sides. Domes are generally built of brick, not moulded to the curve, but simply
laid, each tier a little within the lower tier, so as to form the proper cur\e. The plaster which coats
most of the domes inside and out conceals the slight irregularity of the brick-work. Wooden
frames are also used to support the lighter plaster domes, somewhat like the framework in our
modern fibrous plaster. The
surfaces of the domes are orna-
mented in various ways. Some
are covered with an intricate
geometrical design, with a star
centre, others with bands of zig-
zags or chevrons, running hori-
zontally round the dome from
base to apex. Others again are
fluted, and some are covered
with arabesques arranged in
large outlines, which form a sort
of diaper.

The Sultan Hasan's Mosque
contains some beautiful plaster
decorations and Kufic friezes
(Kufic is a form of Arabic writ-
ing). Illustration Xo. 1 57 shows
a portion of a Kufic frieze from
this mosque; and Xo. 158
shows a portion of a frieze (with-
out an inscription) in the Mosque
of En Xasireeyeh. The Mauso-
leum of Kalaum (a.D. 1284) is
the most perfect e.xample of
plaster ornament in Cairo. The
borders of the arches supporting
what was once the dome, the
borders of the clerestory win-
dows above, and an infinity of
other decorations, are wholly

of plaster, and nothing more delicate and lace-like can be imagined. The bud surrounded bj-
leaves forms a central idea, but it is developed until scarceh" recognisable. The designs are chiefly
characterised b)' a broad treatment of large foliage, worked round into a scroll-like continuous
pattern.

Plaster in this Eastern work is evidence of earl}- date, though it would be difficult to assign a
satisfactory reason for it. Xevertheless, as a fact, the earlier mosques are generally decorated with
plaster work in manj- varied and rich designs. The Ashar, built in 971, is adorned with Kufic friezes

150.-

-Ornamental Plaster Work o.n ihf. .-Vrcake.^ i.s the .Muscle ok
Ibx-Tulun, Ninth Ce.ntl'ry.

422

Plastering — Plain and Decorative.

No. 157.— Plaster Frieze in Mosque of Sultan Hasan, Fourteenth Century.

and arabesque ornament, all in pla.ster work. The plaster work of Cairo is chiefly surface work, jjut
on with tools while the stucco was in a moist state, and never cast in moulds. The difference is
very striking, the softness and flexuous grace of the hand-worked patterns being in strong contrast
to the hard unifirmit}- of mechanical castings.

In both mosques and
houses the ceilings are often
the most beautiful jiart of
a room. The coffered ceil-
ings are formed by the
beams, which are sometimes
allowed to appear in their
natural (half round or round)
form and position. In
houses the outline of the
beams is often preserved
to within a couple of feet
of the end, when stalactites
mask the transition to the
square. The beams, whether
round or square, are covered
with a coating of canvas
saturated with plaster like
The ]3anels between the beams are divided into small coffers, and similarly
and white to give light. All this work is done down
-Another mode of decorating ceilings was to nail
thin strips of wood on to the joists that form
the roof in geometrical designs, and to cover
the whole with a thin coat of plaster on
which arabesques and floral enrichments
were then pressed before the plaster was set.
When di'}', the whole was painted or gilded.
The colours chiefly used are blue and red. A
portion of a ceiling, with octagonal coffered
panels, from the Mosque of Sultan Kalanoun
'fourteenth century) is shown on illustration
\o. 159. The conjunction of the ceiling
with the wall is formed by a stalactite-shaped
cornice, as shown on No. 160. An interesting
feature in connection with this ceiling is the
material used in the formation of the orna-
ment. This is a peculiar kind of carton-
pierre, chiefly made of fibres of palm Iea\-es. Willows, flax tow, and canvas are often found in
plaster work in Eg>^pt. A striking example of an arabesque from the great mosque, Damascus,
is shown on illustration No. 161, and an Arabian panel on No. 162.

That the ancient pla.sterers of the East were proficient in the production of coloured and

our own fibrous ])laster.

plastered, painted red and blue, with gold

and only fixed in its place when finished.

No. 15S.— ri.ASTEk Frieze in the Mosque of En Nasireevei:

Plaster and Glass IVindows.

423

railed ^'f^^ ^ '^^&m^ff^^^^^t^^3^^

impervious plasters is fully attested by the numerous examples herein mentioned. Another
example is the red stucco in one of the chambers of the Pyramids in Egypt, executed about four
thousand >-ears ago. Again, the interior of the ancient cisterns at Alexandria are covered with a
thick red stucco that is not permeable to water.

A curious use of plaster is seen in the windows of mosques and houses in Cairo. Over the
niche of a mosque, and over the
lattice v\'ood work of a nieshre-
blya in a house, one generally sees
examples of the characteristic
stained-glass windows of Cairo.
In houses they are generally set
in a row, in slight wooden frames
over the lattice, to the number
of eight or more. The Cairo
room in the South Kensington
Museum has eleven of
stained windows, which are called
in Arabic kamariyas otshemsiyas,
" moonlike " or "sunlike." They
consist of a rectangular frame
of wood, about 2 inches broad
by I thick, and form an oblong
about 30 inches high by 20
broad. The frame is filled with
an arabesque, floral, architectural,
or inscriptional design in open plaster work, the perforations being filled with stained glass. The
mode of making these windows is the simplest. A bed of plaster is poured into the frame and
suffered to set, and the design is then cut out with a gouge or other tool, after which the stained
glass is fixed with more plaster on the outside of the window, which is then put in its place, flush
with the inside of the wall, and set in a slight wooden frame with a flat architrave round it
forming a margin which conceals joints between the several windows.
A couple of buttons keep the window from falling inwards, while the
architrave .secures it on the outside. It will be seen that no special
skill is required for most of this work. The plaster is easily cut, and
the glass requires no fitting, for its superfluous edges are concealed bj'
the plaster. Where the art comes in is in the shaping of the perfora-
tions which form the design. The shape and slant of these holes are
skilfully regulated according to the height they are to be raised above
the spectator, and the thick plaster setting of the bright little facet.s
of glass gives the light that comes through the latter a shaped appear-
ance which is singular!)- charming. The material is fragile, but moderate care on the part of the
workmen would ensure the safety of the kamartya between its cutting and its placing in the
window. The work could be made considerably stronger hy inserting a twisted galvanised wire
in the outer edge of the plaster while soft, taking care to keep it clear of the perforations in the
A twisted wire is as strong as three pieces of straight wire of equal thickness and

-Portion of Ci.u.ing, K.\la.noin Mos
fourtee.nth century.

,...-. ,^^ V^V Ji

No.

160. — Cornice. Iv manoin
MosgUE, IN Cairo.

design.

424

PInstenng — Plain and Decorative.

length for this purpose. Illustration No. 163 shows one of these curious stained-glass windows.
The original of this and others from Cairo are now in South Kensington Museum.

Through the courtesy of Mr C. Piirdon Clarke, of the South Kensington Museum, I am enabled
to reproduce a portion of very fine plaster work (Plate XLV.) in the mihrab of Abdul-Hacen's
Mosque in Algiers, built in 129(5. A mihrab is a niche in the wall of a mosque, indicating the
position of Mecca, towards which Mohammedans look while praying.

It has alreadj- been stated that the Saracenic style of ornamentation extended to Turkey in
Europe. Turkish ornament may be described as a modification of the Arabian and Saracenic

Na 161.— Arabesque krom the Great Mosque, Damascus.

but inferior to it in elegance and refinement. The decoration of the dome of Soliman 1. at
Constantinople is exceptional in its beauty and excellence of taste. One marked feature in the
colour decoration of the Turks is the predominance of green and black. An example of Turkish
ornament (a frieze from Constantinople) is shown on illustration No. 164.*

Persian Plaster Work.— Although the Persians were a civilised people, very little is
known of their ancient methods of building. The Saracens invaded and conquered Persia in
.\.H. 16 (A.D. 636), in the reign of the Caliph Omar, but the Persian Empire, which extended to the
* For some of the illustrations and notes I am indebted to "Saracenic Art," by Mr Stanley Lane Poole.

Plate XLV.

Plaster Wurk of Mihrai., in AiUirL-UACEN's Mos.'I-e, Algiers, 1230.

Persian Plaster Work.

425

Oxus and Indus, was not conquered till the reign of Moawia. When the Saracens first invaded
Persia they found many magnificent buildings, one of the principal being the palace of Chosroes,
which contained many grand halls, finel>- enriched with plaster work. The city of Baghdad was
founded by the Caliph Mansur. The Djuma Mosque at Ispahan is said to have been built by the
same caliph. This mosque is about 460 feet long and 400 feet wide, and is richly plastered. The
Mosque of Mesdjid-i-Shah was built by the great Shah Abacs I. This mosque is about 420 feet
wide and 340 feet deep, and is decorated with highly
gilt plaster work. There are numerous other mosques,
palaces, and monuments with stalactite domes and
cornices, niches, and minarets all plastered, and in

No. 162. — Arabian- Panel.

No. 165. — Plaster and Glass Window
FROM Cairo.

some cases further enriched with plaster and enamelled tiles, the constructive and decorative
features being their peculiar forms of arches (plain and cusped\ their domes, niches, and stalactite
enrichments which show the wonderful powers and variety of Moslem art.

Mud houses are plastered with a mixture called " kahgill," which is composed of soft mud and
chopped straw. The interior of mud houses are
sometimes ornamented with hand-work gatch or
g\-psum, whereb)- a high finish is produced.
Squire, in his " Land of the Incas," describes
the palace of Chium, where the adobes, or sun-
dried bricks, were covered with stucco, on which
beautiful arabesques were produced.

Perrot and Chipiez, in their " History of
Art in Persia," state that the Persepolitan ornaments imitated at Feruz-Abad— an ancient palace
of Fars (ancient Persia) — were plaster throughout, and they go on to obser\e that the extensive
use, or it ma\' be said abuse, of stuccoed decoration is a distinguishing feature of Arab architecture.
Plaster, when fresh, is soft and malleable in its nature, so that it affords the craftsman an
opportunity of showing his dexterity of hand in those singularly delicate quillings, gofferings,
fillets, beading, and what not ; but there is danger of their merging into mere fineness.

Plaster of Paris, termed " gatch " in Persia, is put to a curious but hideous use in Persia, where
it is used for the execution of prisoners. This form of execution is called " gatching,' and consists

No. 164. — PLAiIEK 1-KIEZE FROM TlKKKV.

426

Plastering — Plain and Decorative.

of a hollow column beiiii,' erected over a hole about 2 feet deep, so that the hole forms a well into
which the prisoner is put. Plaster is then emptied in, and between each boxful water is jjourcd
down the well. The gatch then swells, and when it sets it stops the circulation, causing' the inost
excruciating ajjony and prolonged death. After death a plaster capital is fixed on the column,
covering the head of the ])risoner.

In Persia, where so much attention has been given to decorative plaster work for both outsides
and insides of buildings, honour is given to the plasterer as the most skilled artificer in the building
trades, and the position of general foreman and art supervisor is generally conceded to him. In
England the position of general foreman Or " leading hand " is more often accorded to the carpenter.
In Persia the plasterer reigns supreme among craftsmen — the work of other branches in the building
arts is covered and embellished b\' him. In Persia, and even in some other Plastern nations, the

interiors and many of the exteriors are
^r^wj i ^A^I trciifM covered and decorated with plaster made
from the local gypsum. Persian plasterers
have no idea of using running moulds for
forming mouldings. They literally daub
the stuff on until of the required thickness,
then work it down and fashion the mould-
ings with gouges and drags. This method
is alluded to in Holy Writ in describing
those who cry " peace where there is no
peace " — " they do but daub the walls with
untempered mortar," illustrating the actual
practice of Persian plasterers even at the
]jrescnt day. The Persian plasterers gauge
their plaster in a curious wa\', and one
quite foreign to our ideas. The plaster is
mixed in a pannikin of water in very small
quantities, then worked in the hands by
rolling, squeezing, and drawing it out re-
peatedly — much in the same way as a
glazier manipulates oil putty — until it is
dead, or the initial setting power is killed.
By this process the mass assumes a slight
flexibility. It is then dashed on the walls and ceilings, and spread. This is repeated until a rough
outhne of the proposed work is obtained, after which it is worked as already mentioned. It might
naturally be suppo.sed that this inert plaster would never set or become hard. It does, however,
attain a considerable degree of hardness, probably due to a reaction in the setting of the plaster
caused by the peculiar nature of the crude gypsum. Another cause for a part of its ultimate hard-
ness is the absorption in the brick work over which the plaster is laid. The plaster used for the
ornamental work is mixed with a vegetable juice which acts in a similar way to glue water in
retarding the setting. The decorative plaster work is done in situ.

Examples of eighteenth-century Persian ornament are shown in the accompanying sketches —
No. 165 is a portion of a plaster ceiling. No. 166 is a centre-piece, and No. 167 is a panel from
Teheran. By the courtesy of Mr C. Purdon Clarke I am enabled to reproduce portions of

No. 165. — I'ORiio.M oi- A Ceiling from Tehera.n, Persia.

Plate XLVI.

Portion of a Pi.astkr Ceiling, Persia, Eighteen rii Centirv.

! I

Persian Plasterers.

427

the original drawings for plaster work by Mirza Akbar, State Architect to the Persian Court, for a
Persian palace erected about 1840.* The first (Plate XLVI.) shows a portion (about one-
quarter) of a plaster ceiling, and illustration No. 168 shows a portion of the cornice frieze in the
same apartment. Illustration No. 169 shows a portion of a plaster chimney-piece and wall decora-
tion, and No. 170 is a portion of the cornice frieze in the same apartment. The latter sketch is
larger in scale than the former. These elaborate
but quaint plaster decorations are chiefly modelled
by hand and in situ as already described. Oval
panels and small columns and pilasters are favourite
subjects in Persian decorations. The use of plaster
for the decoration of chimney-pieces is common
in Persian houses.

The late Shah sent some plasterers to the
Paris Exhibition in 1878 to erect a pavilion. This
had an interesting example of a stalactite dome
ceiling. The Persian method of setting out a
stalactite dome ceiling is as follows : — The floor
of the room is first levelled with ashes or sand.
On this a coat of plaster about i inch thick is laid,
floated, and made fair. On this plaster floor a
full-size plan of the ceiling is set out, the working
lines being struck with a line blackened with
charcoal, in the same manner as our plasterers do
on white screeds or ceilings. The plasterers then

cut V-shaped grooves in the plaster, following the black lines and using them as the centres of the
grooves. When this is finished, the plaster chippings are swept off, and the floor oiled with hot
melted suet. On this mould a coat of plaster is laid, to form the first or lowest plan of the ceiling.
When set, it is taken up in sections, and cut into the shapes defined by the projecting ridges. The
plaster slabs are fixed with gauged plaster,
and further supported with wood and reeds
fixed with plaster. The large pendent
stalactites are also fixed with plaster and
supported with iron chains, which are made
rigid by encasing them with plaster. The
plasterers work the stalactites by hand to
the desired form. The next line plan on
the floor is then cast, cut, and fi.xed in the
same way, till the whole series and the ceil-
ing are completed. Their peculiar form of

arch, which is somewhat like the four-centred Tudor arch, or involute curve, is set out with a chalk
line. A pin to fit the perforation of the reel is fixed in the centre of the small radius, and on
this the reel is fixed. A pencil is placed through the loop at the end of the line, and is held by the
hand and moved as the line unrolls, until it reaches the centre line. The same process is used for
the other side.

* These illustrations were traced from the original drawings, now in the Art Library, South Kensington.

No. 166. — Persian Ce.ntre- Piece.

Xo. 107. — Pl.\ster Panel from Persia.

428

Plastering — Plain and Decorative.

Stamsii and Moorish Plaster Work. — The beautiful plaster work of Spain has a distinct
character, being generally carved plaster in fiat relief, admirably adapted for the material and the
clear fine air of the countr>- for w hich it is intended. The characteristic treatment of their honey-
combed ceiling and diapered wall surface are of unusual interest. The Moorish style of diapering
walls with arabesque stucco work came original!)- from Damascus, and forms a sort of connecting
link between the works of the ancients and that of the Renaissance revival in Ital)-. The Moham-
medans being forbidden by their creed to represent the human or animal forms, in ornament
adopted a stjle peculiarly their own, and although thus restricted, they produced a vast variety of
fascinating and elaborate designs and created what is known as arabesque ornament. They were
the inventors of superposed enrichments and stalactite pendants, by which large flat surfaces of
ornament and uniformity of relief and line are symmetrically broken and gracefully accentuated.
Their beautiful geometrical tracery is either interwoven with the stiff and angular Kufic, or in the
African, or incursive letter-forming inscriptions. One of the most wonderful and beautiful examples
of decorative plaster work is that on the walls and ceiling of the celebrated Alhambra of Granada in
Spain, which was the palace of the ancient Moorish kings of Granada. It was commenced in 1248
by the Sultan Ibn-ul-Ahmar, and finished by his grandson, Mohammed III., about 1314.

Plate XLVII. shows a portion of the entrance to the Court of the Lions in the Alhambra
(so-called from the fountain in the centre supported by these animals). It is a parallelogram of

No. 168. — Plaster Frieze from Persia, Eighteenth Century.

150 feet by 50 feet, and is surrounded by a portico with small pavilions at each end. The
portico and pavilions consist of 128 columns, supporting arches of the most delicate and
elaborate finish, still retaining much of their original beauty; the various colours, however, of
the ornaments are now wanting. The portion of the entrance shown is from the corridor which
sejiarates the Court of the Lions from the Court of the Fish-pond, and the illustration shows a
little over one-half of the width. (The centre cusp at the top, and abutting on the plain moulding,
is the true centre.) In order to show the details more clearly the whole height of the entrance is not
shown, and is only taken from a little below the capital of the nearest column. A portion of the
upper part of the wall is also omitted. A small part of the ceiling between this wall and the next
one is shown. The inscription on the band round the spandril of the arch is thus read: "May
power everlasting and imperishable glorj- be the lot of the owner of this palace" (Afr.). "There is
no conqueror but God " occurs several times, both in Kufic and African characters. The elaborate
cusped and pendentive arches are beautiful and wonderful examples of the plasterer's art and craft.

The ceiling of the Hall of the Bark is a waggon-headed dome of most elaborate pattern. It
receives its support at each end from pendentives abutting against the great arches. Illustration
No. 171 elucidates the formation of the pendentives. They are of a vei}* curious mathematical
construction, and are composed of numerous prisms of plaster, united by their contiguous lateral
surfaces, consisting of seven different forms proceeding from primary figures on plan. They

Plate XLVII.

m^sMii:^'.

^fp?

■•|c

!^M ^F'M^

J^K^.^^,.,>^ J^_^,^^^y^^ . ^^.^ . ,

MiiiW^i^HlMSl

Moorish Plaster Work— Entrance to the Coiri of the Lions in the Alhambra, Spain, Thirteenth Century.

Moorish Plastey Work.

429

are the right-angle triangle, the rectangle, and
the isosceles triangle. A, B, and C respectively in
Fig. I. In these a a, a b, a c are equal, b a \s
equal to bb, and the vertical angle of the isosceles
triangle (c) is 45°. The figure B has one form
in section, the figure A three, and figure c three ;
the third (c 3) being a rhomboid formed by the
double isosceles triangle, as shown in Fig. 3. The
curves (lettered x) of the several pieces are
similar, by which it will be seen that a piece may
be combined with any of the others by either
of its sides, thus rendering them susceptible of
combinations as various as the melodies which
may be produced from the seven notes of the
musical scale. The letters on the plan (Fig. 2)
and the elevation (Fig. 4) correspond with each
other, also the section (Fig. 3).

The conical ceilings of the Halls of Justice,
Abencerrages, and Two Sisters, as well as the
column capitals and arches of a similar construc-
tion, are formed with these plaster prisms. Nearly
five thousand enter into the construction of the
ceiling of the Two Sisters ; and although they
are simpl\- of plaster, strengthened here and there
with pieces of reed, no part of the palace in the
present day is in a more perfect state of pre-
servation. This pendentive construction attests
the wonderful power and striking effect obtained
by the repetition of the most simple elements.

The arabesque work is executed in pin-
point stucco, and unlike the general work, is
principal!}- carved, not cast, the original stucco
plaque being brightly coloured in the primary
liues. The arabesques covering the walls seem
to be hand-worked with great care and patience.
" The process employed was simple. Prepara-
tory to applying the decoration, the naked
walls were divided by lines at right angles, such
as artists employ in producing pictures. A series
of intersecting segments of circles were then
drawn over these, and bj- their aid the artist
could work with quickness and surety. The
great instrument of the Moorish artist was the
compass, which, however, was not made in

the usual way of two limbs of metal joined, xo. ibg.-i'LA^rERCHiMNEv-l'uiCEA.NDW.^LL Decoration,

Persian, Eighteenth Century.

430

Plastering — Plain and Decorative.

It was a fixed measure tied by a string, so tliat for each dimension there was a different
compass."

A part of the diaper panelling in the Hall of the Ambassadors is shown on Plate XLVII 1. The
arches of the l-'ish-pond arc profusely decorated with perforated ])laster2ornament and inscrii)tions

No. 170.— Plaster Frieze, Persia, Eightekmii Ceniury.

in Kufic characters. Plaster casts from the original works are to be seen in the Alhanihia Court at
the Crystal Palace, London.*

The Moors were always distinguished by the beautiful use they made of plaster. The patterns
used are generally such as in stone work would be unhesitatingly attributed to the end of the

fifteenth or first half of the sixteenth

A I

A2. 1

"Ifi

F,^3.

centur)-. Mr G. E. Street, when de-
scribing Moorish plaster work, says
that "plaster may be used truthfully
and artisticall}', and without any
approach to the contemptible effect
which the imbecilitj' and dishonesty
of the nineteenth-century designers of
plaster work have contrived to impress
on almost all their productions." The
walls of the facade of the Alcazar
and other buildings in Segovia are
diapered in plaster. The\-arc generally
tracery patterns of the latest Gothic,
left slightly in relief, and repeated over
and o\er again so as to produce a
regular diaper throughout. This mode
of decoration seems to have been very
popular in the fourteenth and fifteenth
centuries. Mr Street is of opinion that
the diaper work " was executed with
a frame cut to the pattern, so as to
allow of the ground being cut back slightly, leaving the ]5attern lines formed in the original
face of the plaster. This kind of decoration seems to be perfectly legitimate, and here, owing
to the care with which the plaster had been made and used, it had stood remarkably well,

* The sketches and part of the description of the Alhambra are taken from Owen Jones' grand work on that
wonderful building.

Fij.a. Pi-*M.

r-%*

F,^.l.

No. 171. — Setting out Plaster Prisms for Pendentive Ceilings.

Plate XLVIII.

Diapered Plastek Panfxi.ino in the Alhambka, Spain, Thirteenth Century.

Spanish Plaster Work. 431

though most of the patterns (that he saw) had evidently been executed in the fifteenth century." In
the front of the Alcazar these piaster patterns are carried not only all over the plain face of the
walls, but also round the towers and turrets of the angles, so that the smallest possible amount of
wrought stone is used.

The front of a private house near San Esteban is another fine example f)f the same kind of
plaster work. The patterns in the plaster are three in number, the first carried from the stone plinth
up to the sills of the principal windows, where it is cut by a narrow band of ornament, acting as a
string course to di\ide it from the second pattern, which is carried up to the eaves, the tower being
covered with a third diaper rather less intricate in design. Near this house is a tower in the walls
even more worthy of notice. It is of very considerable height, quite plain in outline, and only
pierced with one or two square-headed windows, but surmounted by a fine parapet supported on
machicoulis. The whole tower is built with bold stone quoins and horizontal bands of brick work,
each band two courses in height, at intervals of about 3 feet. Between these bands the walls are
plastered and diapered. Here, as in the other house, only two or three patterns are used, but greater
judgment is shown in the repetition for the greater part of the height of the same pattern, which is
changed at last near the top where it is desirable to emphasise the work. Most men having three
patterns to use would have divided them equally, but the real artist gives all their value to his
simple materials by not doing so. The construction of this tower led naturally to its decoration.
The wrought stone at the angles, the rough stone work of the walls, and the occasional bonding
courses of brick, were all used simply as the best materials for their respective parts ; and the rough
stone work being plastered and diapered, gave a richness and polish to the whole work which it
would otherwise have wanted, whilst it in no degree destroyed the air of stability of the wall, which
is secured by the obviously constructional arrangement of the stone and brick. The above descrip-
tion of this highly interesting constructive and decorative work is noteworthy, and will afford many
suggestions in plaster decoration in combination with stone and brick work.

Madrid, being a comparatively modern city, has little plaster work of interest. There is a
growing fashion of diapering houses all over with a kind of thirteenth-century painting on plaster,
but the work is not nearly so effective as the incised plaster work previously mentioned. When
Philip II. was building the Escurial at Madrid, he sent for Pelligrino to assist in the plaster
decorations. Pelligrino (who was with Primaticcio at Mantua) gave a Renaissance character to the
incised plaster work which had since the ^Moorish occupation prevailed in Spain. Toledo possesses
many rich and interesting examples of plaster work.

In a synagogue founded in the twelfth century, but seized in 1405 by the Toledans, and dedi-
cated as a church under the name of Sta. Maria la Blanca, the application of plaster work is
conspicuously exemplified. There are eight horse-shoe arches springing from octagonal columns in
the arcades, and the whole of the columns and capitals are executed in brick, and finished with
plaster. The capitals are very elaborate, but slightly varied in design. All Moorish decorative
work seems to have been executed in the same waj*. This was of very fine qualitj", and was
evidently cut and car\ed as if it had been stone, and seldom, if ever, stamped or moulded according
to the practice of the present day. The consequence is that there is endless variety of design
everywhere, and any amount of undercutting. There is another synagogue in Toledo, erected in
1366 by Samuel Levi, a rich ]e.\v. After the expulsion of the Jews from the kingdom in 1493, it
was converted into a church called " Del Transito." The building is a simple parallelogram, 76 feet
long by 3 1 feet 5 inches wide. The lower portion of the side walls is quite plain, but above it is
very richly adorned with plaster work. There is first a broad band of well-relieved foliage.

432 Plastering — Plain and Decorative.

with Hebrew inscriptions abosc and below it, and above this, on each side, an arcade of
nineteen arches sprinyint^ from coupled columns (with elaborate capitals), eit^ht of its di\isions
being pierced and filled with very elaborate lattice work. The end wall t<j within 7 feet
of the floor is covered with rich patterns, inscriptions, and coats of arms. The arcades are all
cusped in the usual Moorish fashion, the outline of the cusps being horse-shoe, but without an
enclosing arch. Plate XLIX. shows a portion of one of the side walls, with the inscriptions, arcade,
and lattice work. It will be seen that the main ornament on the wall and the capitals \ar}- in design,
thus adding to the general effect.*

Manj- of the facades and walls of buildings in other towns in Spain have their plain surfaces
covered over with incised patterns cut into the plaster ; the roughened surfaces of the abraded
ground giving in that bright climate, when bounded b\- the clean-cut shadow or brightl)--lit edge
of the salient parts, a different tone from that of the main surface, forming, in fact, a coarse
sgraffitto. Some of this work is coloured, which adds to the general effect.

Indi.VN Pl.VSTEKING. — The history of the plaster work of Indian fabrics, even of modern
date, is involved in obscurity. There is ample e\idence of the artistic ability of Indian plasterers
to be seen in the numerous palaces, temples, &c., to be found in all the principal parts of India.
The walls of the rooms at Kandahar, Afghanistan, were plastered with gypsum, and decorated
along the cornices with arabesque patterns stamped on whilst the plaster was moist. On this
decoration, in its j-et moist state, coarsely pounded talc was pounded on, which during daj^light
shone like frosted silver, whilst by lamplight it sparkled like diamonds. In the North of India a
lime known as "kankar" is generally u.sed for plaster work. Burnt brick when ground to powder —
known as " sukhi " — is, as a substitute for sand, mixed with kankar lime.

In the Ganjam district of the Madras Presidencj- the natives rarcl)' use sugar in common
building mortar, but in Chunam the plasterers use for ceilings, walls, and verandah pillars a good
deal of sugar {clieeney). The materials used are 100 lbs. of good slaked shell lime, the white and
yolk of 16 eggs, i gallon of fre.sh butter milk, 25 lbs. of fine sifted clean sand, i lb. of fresh
butter, lA lbs. country sugar, and 50 lbs. of water. These materials are all well mixed together,
placed in a covered tub, and allowed to remain for three days before using. When this is set it
takes a high polish, and has a marble-like appearance, and it will stand washing with soft soap
water. The Madras Cathedral is a good example of native plastering, which is done in one, two, or
three coats, as required. The following is the general mode of Indian plastering: —

One-Co.\t Work. — The mortar is composed of i part of shell lime and 2 parts of clean
river sand. This is well mixed and beaten up with a wood beater, and allowed to stand until
required. When wanted for use, it is knocked up with water in which jaghery has been dissolved in
the proportion of i lb. of jaghery to each gallon of water. The mortar is then laid on with
a trowel, and floated with a flat wood rule. It is then finished with a wood rubber, sprinkling the
face of the work with water in which pure shell lime has been mixed. The rubbing or hand
floating is continued until a smooth face is obtained. This one-coat work is scarcely i inch
thick when finished.

T\vo-Co.-\T Work. — The first coat is laid as in the former process, only no lime water is used
for hand floating, and the surface is left rough to receive the second coat. The first coat is allowed
to stand for one or two days (according to the state of the atmosphere;, and while semi-dry the

* The illustration of plaster decoration in the synagogue is from a photograph kindly placed at my disposal by
Mr C. Pardon Clarke, F.S.A. Many of the foregoing descriptions of plaster work are from "Gothic Architecture in
Spain," by George E. Street, A.R.A.

-I

H
z

Indian Plaster IVork. 433

second coat is laid on. This is composed of 3 parts of shell lime and i part of fine white
sand. These are gauged with the jaghery water, and allowed to stand as before. It is then
ground on a large flat stone by means of a small stone roller until 'the gauge is reduced to a very
fine paste, something like our fine putty. It is laid on about jt inch thick with a broad wooden hand
float, and floated with a trowel used in a similar manner to hand floating. It is ne.xt polished with
a crystal or smooth stone rubber until it has a fine smooth polished face. Afterwards it is sprinkled
with \ery fine powdered ballapam (soapstone or steatite), which is kept in a cloth or fine muslin
bag. The sprinkling or dusting is done to increase the whiteness and assist the polishing. No
more is laid on than can be done in one day, as it may harden too much during the night to be
polished the following morning. The work is polished and dusted until it is quite dry. A
number of plasterers are employed in the polishing, so that the work in hand can be finished
the same day as laid. The drying is further hastened by frequently wiping with soft cloths. When
this class of work is finished it has a very fine appearance.

Three-Coat Work. — The first coat is done the same as for two-coat work, with the excep-
tion that it is allowed to stand for two weeks or until dry. The second coat stuff is compo.sed of
I part shell lime and i part of well-washed river sand. These are well beaten up in a wooden'
box or trough. The first coat is slightlv- damped with clean water, and the second coat is laid on
about ] inch thick with a wooden hand float, and then rubbed or hand floated until the work
is consolidated and even on the face. After standing a day or two, or until dry, it is ready for
the third coat. This is made in two operations, the materials for the first being 4 parts of shell
lime and i part of well-washed white sand, mixed with jaghery water, and reduced bj' grinding
(as before described) to a very fine putty paste. This is allowed to stand until the other portion
of materials are mixed. This is done by placing in an earthenware jar the whites of twelve eggs,
a half gallon of whey with the curds, and well mixing, after which this is added to half a gallon of
the putty paste, and rubbed together until the whole is thoroughly incorporated and reduced to a
fine thin paste. It is then covered up and allowed to stand until the e.xtra fine stuff for the second
operation is gauged. This is simply pure lime ground to a very fine powder, mixed with water in
a trough and well stirred until it is of the consistency of cream. This is kept covered up until
wanted for use. The first gauge is now well stirred and laid on the second coat, a bare ^ inch
thick, with a broad hand float. It is then gently floated to lay it fair and firm, and next brushed
over with fine lime cream, and floated gently with a hand-float first, and then more firmly with a
trowel, until it attains a slight hardness. It is polished with a crystal or white pebble, being
sometimes first rubbed with a piece of steatite. The crystal is generally about 3 inches long and
li inches wide, and has a perfectly smooth face. While the polishing is in progress, the dusting
with the powdered soapstone is frequently used, and the moisture wiped off with soft dry cloths-
The polishing is continued until the work is perfectly dry. This beautiful marble-like plaster
stands all the changes of the Indian climate, and is exceedingly durable.

The success of this process depends on the proper quantities and gauging of the different
materials, especially for the third coat, on its being floated carefully, and on the polishing with the
crj'stal and powdered soapstone (with intermediate absorption of moisture by cloths) until the work
is quite dry. As in our own country, the process and proportions of materials vary more or less in
the different parts or presidencies of India.

Steatite or soapstone pulverised to a fine powder has been used for plastering walls and ceil-
ings. It takes a high polish, is pcarl}--grey in tint, and gives a fine surface for painting either in
oil or water colour, and is hard, non-conductive, and non-absorbent. It can be washed, and when

434

Plastering — Plain and Decorative.

subject to heat, moisture, and chemical fumes, it gives no smell, and does not turn )-ello\v
with age.

Besides the talc already mentioned for obtaining sparkling surface effects on plaster work,
ground glass is also used for a similar purpose. The ground glass is sprinkled over a damp cloth,
which is then turned over, so that the surplus or drj- glass falls off; then the glass side of the cloth
is applied to the ceiling while the plaster is moist, and the under side beaten or pressed until the
glass is impressed into the plaster ; the cloth is then taken off, leaving a uniform coat of glass on
the surface of the plaster. Another mode of using glass in combination with plaster for decorative
purposes is as follows : — Glass cubes of various sizes, forms, and colours are inserted by hand into
the soft plaster. By this process a curious combination of coloured surfaces with glittering effects
is obtained.

The following composition for indurating and protecting plaster exposed to the weather is
frequentl)' used in India, viz., 3 parts of linseed oil boiled with one-si.xth of its weight of

No. 172. — Indian Centre-Piece.

Indian Cfntre-Piece.

litharge, and i part of virgin wax. The surface must be perfectly dr)- before the composition is
laid. It should be used hot, and laid with a brush.

Two centre flowers from India are .shown in illustrations Xos. 172 and 173. An excellent
example of Indian plaster work is exhibited in Plate L. This shows part of a ceiling and wall
in the tomb of Jamrili at Delhi. The transition from the square or plain to the round by means of
an octagonal gives a fine opportunity for ornamental plaster work. There is a great similarity in
the style of this ceiling to the Moorish plaster decoration in Spain and North Africa. Shaikh
Fazl-ullah, alias Jalal Khan, but better known by his nom-de-plume of Jamali, was a great traveller,
a man of literary fame, and a poet. In the year A.H. 935 (.\.n. 1528) he built a mosque and a room
— afterwards his tomb — in the old village of Outb Sahib, and the ruins of the village may yet be
seen in their neighbourhood. Jamali accompanied Humajnin to Gujrat, where he died on the loth
of Qiqa'd, in the year A.H. 942 (A.D. 1535). His body was brought to Delhi, and interred in the
room which he had occupied as a dwelling during his lifetime.*

* Carr Stephen's "Archaeology of Delhi."

Plate L.

Ci^:--^-

ClilLING.

Plastkr Ceiling and Walls in a ToMb at Delhi, 152S.

Chinese Plaster IVork. 433

Mr Lundgren tells a curious story about Indian plastering. When in India after the Mutiny,
making sketches in the Punjab, he and his interpreter being overtaken by a storm, sought shelter in
an unfinished tomb. The ceiling had just been plastered, and was still soft. A native came in, and
with three laths measured the length and width of the ceiling. He then cut the ends of the laths
into different shapes, somewhat like modelling tools. After this he got on a tub, set out some lines
on the ceiling, and began modelling an elaborate design on the soft plaster. Lundgren being greatly
interested, stayed until the plasterer left. He then turned to his interpreter, saying that this
plasterer was the cleverest man he had ever met with. The interpreter, with a look of surprise,
replied, " He is an idiot." Lundgren rejoined, " I have been an artist for forty years, and I could
not do such a thing straight off" The interpreter said : " His father was a clever man ; he could
do five patterns. He had three sons ; one could do three patterns, one two, and this idiot can only
do one."

Chinese Plaster Work.— In China bricklayers and plasterers are united. This two-branch
operative possesses the accomplishments of modeller and designer of interior and e.xterior enrich-
ments, which are produced without working drawings. He creates cornucopia; in circular pediments
over windows ; designs and models centre flowers, enriched with foliage and flowers ; arranges birds
and fishes on rain-pipe heads ; executes panelling in parapets and works up cornices with exceeding
patience by hand ; rejecting straight-edges, running rules, and running moulds, and all such line and
rule formalities, rather crippling his mouldings, however, in his independence. The ornamental
work is all done in situ by hand. In order to protect these works on the exterior of a building until
the plaster is set, an immense cage (tap pong cliong) of bamboo is reared so as to enclose the whole
edifice. A good thatching of leaves shelters the stucco work from the heavy rains, that would
destroy in a night the work of months. A remarkable feature in the ornamentation of stuccoed
fronts is the introduction of ventilating apertures near the main cornice, which communicate with
flues that open into the roof when there are plastered ceilings. Other ventilators pierce the slope
that connects the walls and ceilings, an inclined plane conforming to the rake of the roof, and lathed
upon very slender battens, which serve for ceiling joists. Lath and plaster partitions are sometimes
constructed, but boarded divisions are more common. The setting coat of internal plastering is
mixed with shreds of white paper, which supplies the place of hair. The lime sets exceedingly hard.
The Chinese delight to wash the plaster with a blue colour. Stone mortar {shia/ooi) is lime mixed
with coarse grit. Lime mixed with red mud is used for brick-work.

IT.\LIAN Pl.\ster Work. — Italy has always been the nursing mother of plasterers, and in
Mr G. T. Robinson's " Glimpse of the History of the Art and Craft," he has shown something of
her great and glorious past, and how she sent her sons over almost all Europe to raise the art
and status of this craft. Even during the depressing times of her history she religiously preser\-ed
its ancient traditions and processes, and in almost all her towns there was some one or two
plasterers to whom were confided the restoration, the repair, and the conservation of its frescos or
its stuccos. The art dwindled, but it survived. So late as 1851 an English architect, when
sketching in the Campo Santo at Pisa, found a plasterer busy in lovingly repairing portions of its
old plaster work, which time and neglect had treated badly, and to whom he applied himself to
learn the nature of the lime he used. So soft and free from caustic qualities was it that the jjainter
could work on it in true fresco painting a few days or hours after it was repaired, and the modeller
use it like clay. But until the very day the architect was leaving no definite information could he
extract. At last, at a farewell dinner, when a bottle of wine had softened the way to the old man's
heart, the plasterer exclaimed, " And now, signor, I will show you my secret ! " And immediately

436 /^/(jsfcj'iiip- — P/nvi and Decorative

rising from the table, the two went off into the back streets of the town, when, taking a key from his
pocket, the old man unlocked a door, and the two descended into a large vaulted basement, the
remnant of an old jjalace. There, amongst the planks and barrows, the architect dimly saw a row of
large vats or barrels. Going to one of them, the old man tapped it with his key ; it gave a hollow
sound until the key nearly reached the bottom. " There, signor ! there is mj- grandfather ! he is
nearly done for." Proceeding to the next, he repeated the action, saying, " There, signor ! there is
m>- father! there is half of him left." The next barrel was nearly full. "That's me!" exclaimed
he; and at the last barrel he chuckled at finding it more than half full: "That's for the little
ones, signor!" Astonished at this barely understood explanation, the architect learned that it was
the custom of the old plasterers, whose trade descended from father to son for many successive
generations, to carefully preserve any fine white lime produced by burning fragments of pure
statuar)-, and to each fill a barrel for his successors. This the\- turned over from time to time, and
let it air-slake in the moist air of the vault, and so provide pure old lime for the future by which to
preserve and repair the old works they venerated. After-inquiries showed that this was a common
practice in man)- an old town, and thus the value of old air-slaked lime, such as had been written
about eighteen liundred }-ears before, was preserved as a secret of the trade in Italy, whilst the rest
of Europe was advocating the exclusive use of newly burnt and hot slaked lime. Was there in the
early part, indeed even in the middle, of the present century, any plaster image seller who was not an
Italian ? Indeed, at this present time, almost all the " formatori " or piece moulders for the majority
of the sculptors of Europe are of Italian nationality or descent, and chiefly b)' these has the national
craft been maintained.

When after the long European wars of the eighteenth and the commencement of the nineteenth
century Ital}- had rest and power to "make itself" {faro de se), the first revival of its industry
was felt b\- her plasterers, and as there were then, as now, more workmen than work, they emigrated
to the neighbouring countries ; and the major part of the plasterers along the Riviera, in the southern
provinces of Germany and Austria, are Italians, who go off with and return with the swallows, to
earn that wage the povertj- of their own country cannot afford them.

No sooner had the new kingdom of Italy founded itself than the attempts to revive the old
triumph of plaster work began. Sgrafifitto was revived in Florence and Rome, and in 1890 the
endeavour was made to re-create the grand old modelling of the gorgeous ceilings which had once
been the pride of Venice, and the Papadopoli Palace succeeded in almost reviving the work of
Vittoria, which has already been referred to. The Baron Guggenheim, an antiquary and a dealer in
many good things, old and new, set himself to work, and here is his description of the process which
he kindly communicated to Mr Robinson, who has placed it at my service. " The materials," says
he, " were stone lime slaked for three or more years, and ' marmarino,' that is to say, marble dust
from Carrara, jjounded ver}- fine into an impalpable powder, and most carefully selected and dried
in an oven, with which to cover up the lime, which was then left for another year to graduall)- mix
itself with the marble. It was then tempered into a paste until it was equally plastic as the clay of
a sculptor, and with this you could model with equal ease. When partiall}- set you dust the model
over with the finest marmarino, and when quite dry, brush it and wash it off." The heavy masses
were cored with ordinary mortar lightened by reeds, coke, charcoal, and other light substances.

As already stated, Henry VIII. brought several plasterers to England. There is still extant
the will of the head of a travelling company of Italian plasterers in England, by which he left all
his tools to his fellow-artists. The Italian plasterers are adepts in the working of coloured stuccos.
Several of the ancient Roman baths which have been excavated in England in the present century

Italian Plaster Work.

437

were lined with a fine red impervious stucco. This material also formed the floor surface. This
proves that the colours were durable, and that the stucco was of a hard nature, otherwi.se it would
not ha\e been used for floorings. Coloured wall plasters, in fine preservation, have also been found
in several old Roman villas discovered in England.

In addition to the e.Kamples of Italian plaster work already demonstrated in the introductory
chapter, several others are given here. Illustration No. 174 depicts portions of five coved ceilings
(with details of pateras) for circular rooms, designed by M. Angelo, Bartolomeo Ammanati, Baldas-
sare Peruzzi, and Algardi, and executed in the Capitol (sixteenth centurj'), the Palazzo Mattel
(1564), and the Villa Pamfili (16441, at Rome. No. 175 displays two enriched soffits of arches

^ No. 174.— Coved Ceilings of Circoiar Rooms, krom It.alv.

designed by Raffaelle and Ammanati, and executed in St Peter's (sixteenth century) and the
Palazzo Mattei, Rome.* Illustration No. 176 exhibits a stucco frieze from the Ducal Palace,
Venice, designed by Giac. Albertolli in the eighteenth century.

Italian Stucco.— Stucco for decorative purposes is supposed to have been invented by
Margaritoni, who died in 1317- This stucco was composed of old lime putty seasoned by age,
mixed with fine marble dust, and in some cases fine sand and hair. The whole mixture was
frequentl)- turned over and well beaten with wooden beaters, a little water being added at each
turning. The mixture was then laid on brick floors to absorb the moisture. Afterwards ,t vvas
taken up and well beaten, until the mass was plastic, tough, and cohesive. Th.s stucco was further
* These illustrations are taken from Sir W. Chambers's treatise, "The Decorative Part of Civil Architecture."

438

Plastcyi>ig — Plain mid Decorative.

improved bj- the adding of a small portion of burnt gypsum. The gypsum was burnt in a similar
manner to lime, instead of being burnt in an oven. The stucco sets in from ten to twelve hours,
according to the amount of burnt gypsum used. This stucco attained great hardness, and was
usually called stucco ditro, or hard stucco. It was the principal stucco used before the introduction
of lead or wooden moulds, and was usually modelled in situ by hand. A different mode of working
was introduced by Vittoria (a pupil of Giacomo Tatti), who pressed the plastic stucco in situ with
lead or wooden stamp moulds. The general outline was defined by the mould, the details being
worked up bj- hand. When the design was large or repeated, the stucco was pressed into the
moulds, and the details worked up by hand after the main parts were fixed.

Stucco for plain plastering is generally
done in three coats. The methods are some- .
what similar to our own, but the materials
vary slightly. The first coat is done with
ordinary coarse stuff, and the floating coat
with stuff containing a larger proportion of
lime. The finishing coat is made of rich
lime, and after being slaked the putty lime
is allowed to stand for three or four months
before it is u.sed. It is then frequently beaten
up and mixed with ground Carrara marble,
and for internal work with gypsum. The
ground marble and putty lime, made into a
stiff paste in equal quantities, is well beaten
till the whole is perfectly homogeneous. This
is then laid on about \ inch thick, and then
scoured and trowelled to a smooth surface.

F"rench Plaster Work. — The plastic
decoration in the salons of France is largely
composed of papier-mache, such as the decora-
tions in the Hall of the Council of Henri II.,
the Louvre, in the rooms at St Germain, and
the Hotel des Fermes, &c. Carton-pierre has
also been extensively used for the same
purpose. The most notable examples were
to be seen in the Tuileries, and also at the
Palais Royal, and portions of the Louvre. Modelled plaster or stucco was first used about the
beginning of the sixteenth century. Good examples are to be seen at the Gros Horologe at Rouen,
e.xecuted about 1530, and the Manoir of Yville-sur-Seine. Stucco chimney-pieces and wall decora-
tions of considerable merit are to be found in many parts of France, especially in the vicinity of
Toulouse. There are fine examples of decorative plaster work in the Louvre, executed b}- Van
Ostell and M. Arnoldin. Plaster of Paris has been the prevailing material for both plain and enriched
facades for ages. Victor Hugo, in the " Hunchback of Notre Dame," punningly remarks in the
description of Paris, that " our fathers had a Paris of stone ; our children will have a Paris of
plaster." Typical examples of French plaster work are shown on Plates XX. and XXI.

French architects .sometimes use plaster work in situations where the presence of plaster

-Enriched Soffits ok Arches, fro.m St Peter's
AND THE Palazzo Mattei, Rome.

French Plaster IVork.

439

work would not be suspected. For instance, in the Bibliothcque Nationale, Paris, the coffers and
other ornamental work which spring from the piers in the hall are plaster work of good quality,
but from its great height, and the absence of plaster work in other parts of the hall, would not be
suspected. Again, in the Church of the Holy Trinity, the richly decorated interior of which is

No. 176.— Stucco Frieze from the Ducal I'alace, Venice, by Giac. Albertoi.li, Eighteenth Century.

in stone, with the exception of some massive pillars separating the galleries from the body of the
church. These alone are of plaster work, and among the best plaster work in Paris ; and these
columns harmonise completely with the colour of the stone work, so that even when close to
them one would not take them for other than stone work. The ceilings in many of the secular

No. 177.— Cartouche, ero.m the Uibi.iotheque Nationale, Paris.

buildings are seldom enriched with plaster mouldings, but thc\- are imitated in oil paint or in water
colours. The annexed sketches exemplify a Renaissance style of Flemish origin sometimes seen
in France. Xo. 177 is a cartouche from the Bibliotheque Nationale, and No. 178 is a cartouche from
Lyons.

440

Plastering — Plain and Decorative.

With rec;ard to plastering generally, there are two methods employed in France. The first is
somewhat similar to our method of forming concrete floors and walls. A centring of wood is formed
in a line w ith the proposed ceiling, and then the gauged plaster is poured on from above. Partitions
are formed in a similar way. The second method, as executed in Paris by Frenchmen, seems to be
far behind our own, though they turn out fairly good work, but with a waste of material that would
soon make an Knglish employer bankrupt. For example, for a plain ceiling about lO feet by 12

feet, four men are employed, two ]jlasterers
and two labourers (or companions, as they are
called). The plaster is turned out in a loose
heap on the floor, and the labourers, who are
supplied with boxes which contain about 2
bushels, half fill two of them with water, and
add sufficient plaster to make it of a pro]jer
consistenc)'. The boxes are then placed on
the scaffold, and the plasterers begin to mix
with the left hand and a trowel in the right.
This trowel is made of brass, in the shape of a
\ ery wide gauging trowel, about 5 or 6 inches
in width and tapering to 4 inches, with a
length of 7 or 8 inches. The point being cut
off straight, it is adapted to fit the corners of
the box, and leave it clean as soon as the
plaster begins to set. When the plaster is
gauged, they splash it on the part they mean
to cover. By the time this is done the plaster
begins to thicken as it begins to set, and then
they take it out with the trowel on to a hawk
of a peculiar construction. It has a handle
about 9 inches long, the board is about 18
inches and 1 1 inches wide, and the longest
edges are formed of two strips of hardwood
flush with the board. Having placed sufficient
stuff on this to conveniently manipulate, they
press the stuff on it against the part to be
plastered, and spread it about with the flat face
of the hawk, using the hard edges backward
and forward to bring the work to an even
surface. Two men to each box empty it, and
by this time the companions supply them with a fresh pair of boxes, and so on until they have
covered the whole flush with a narrow screed, formed by filling to a straight-edge bearing on dots
of the required thickness. Thej- then start to straighten the whole surface by scraping off all the
bumps which are inevitable by their method of application. For this purpose they use a toothed
drag. This is constructed of a steel blade about 8 inches long, toothed on one edge, while the
reverse edge is straight, with an iron bow fastened to each end of the blade and a handle attached
to the apex of the bow. With this they scrape down the inequalities, using the toothed edge till

No. I7S.— CARTOUCHE, FROM LVONS, FRANCE.

French Plasterers. 441

they get a fair surface, by which time the scaffold is covered deep with plaster, in which they tread
about till the companions shovel it down off the scaffold. They then use the reverse end of the
drag, and so scrape the surface to a smooth face.

It will be readily understood by anyone having even an elementary knowledge of the methods
adopted by English plasterers that two men could do the work of these four with more certainty of
being correct, and in less time, without the waste incurred by the French system. In the English
system there is art scientifically applied ; theirs may be art, but without science. Their method of
forming mouldings is as ours, with running mould and running rules, only they use all plaster ; but for
the mitres they have no notion of our system of working and taking off the stuff while in a plastic
state with the joint rule. The>', on the contrary, fill the mitre with gauged plaster, and with a series
of tools of a plane-like form shave the stiff stuff off till the>- form the mouldings to a mitre, just as
a mason would do with soft stone. Many of the men who do plastering in Paris are masons, or
have been closely allied to them in their training. So much is this the case that they form one
bod}- for all general purposes, and at the Bourse du Travail they are recognised as one trade.
This may in some measure account for the ajiparent similarity in their methods of doing work.
The material also admits of this mode of treatment. It is plaster of Paris always, and nothing but
plaster, except in rare instances, and plaster of a wholly different consistency to ours, for when
gauged their ordinary plaster is of a loose granular quality, and has a somewhat soapy character in
working, which makes it easy to cut and drag.

So far is plaster brought into use, that not only are the interiors done with it, but also large
and imposing fronts with cornices, architraves, pediments, pilasters, columns, and all the other
adornments that go to make classic architecture, or the expression of the architect's ideal in any
st}-le or combination. This will seem strange to many English plasterers — for, according to our
insular notions, plaster will not stand exposure — yet in Paris all the houses that are built of rubble
stone are faced in plaster, and it stands good for many years. The material is so cheap that if it
does fail in any part it can be easily and cheaply renewed.

It is a common occurrence to see the fronts of large and handsome hou.ses replastered out-
side, and though the fronts are only a little smoke-begrimed, yet they are stripped of the entire
plastering, and done afresh in the semblance of a nice soft white stone. No paint being applied
annually or bi-annually to these fronts, so much as it would cost could be saved to replaster them,
and thus have a new front for another series of years. Lime and sand with hair, as we use them,
are unknown, or nearly so ; but where it might be expected that the strain of the expanding
plaster would lead to cracks, as over bracketing in cornices or the like, they use a large quantitj-
of tow in core, which they lay about and mix in with the plaster while in a plastic condition.

Plaster is the general material for interior and external work. Carton-pierre. papier-machd
(as previously stated;, and fibrous plaster (termed staff) are extensivel\- used for decorative pur-
poses. Portland cement is rarely used except for concrete work. Parisian plasterers are a
courteous, sober, and generally thrifty body of men. In working attire their everyday clothes are
well protected by a large clean blouse, which looks better and seems more adapted for the
purpose than the scant)- jacket and short apron (often only the latter) as worn by most of the
London plasterers. Their wages vary from 8d. to 8kl. per hour. The\- work ten hours in summer,
and eight to nine hours in winter— Sunday included. But few of them work more than six days
in any one week ; if they do, they generally take a holiday the next week. They have little or no
piece-work, and the}- are paid monthh^ on the first Sunday in the month. They have no rushing or
driving, as is often the case in London. Xo one seems in a hurr}-, }-et none seem to be idling.

442

Plastering — Plain and Decorative.

The trade is generally regular throughout the year in Paris. There is an interesting description of
Parisian plasterers in the " Artisans' Report to the Mansion House Committee on Plastering at the
Paris Exhibition, 1889," by Mr T. Smythe, plasterer, London.

Carved Plaster Work. — In and around Paris, many of the large mansions have their
entrances, halls, and principal staircases decorated with carved plaster. The work is done in situ,
and the material is prepared and manipulated in a peculiar way. It is composed of coarse plaster
and finely ground lime, and is worked up exactly in the same manner as that employed by the
Persian plasterers (described on page 426). It is then laid on the walls and ceiling, and made level
with the trowel. When partially dry it is wrought to a fair surface with drags, and then the
ornamental parts are carved like soft stone. When perfectly dry it is rubbed down with a fine
sandstone, and is then as like stonework as possible. This work becomes exceedingly hard, and is
very durable.

\o. 179.— Portion of 1'laster Ceuint. (Modern German), Df.sig.nf.d and Modelled by K. .Schirmer, Berlin.

German Plaster Work.— German plasterers make excellent work. Their method more
nearly approaches to the English than that of other Continental workmen. They have good
designers and modellers. The Government authorities take a great interest as to the best kinds of
materials and methods of working. They also give great encouragement to fireproof construction.

German Plaster Work.

443

]t is a noteworthy fact that floors protected with plaster work have given the best results. Neat
plaster is used for slab work, also ordinary plastering on a network of wood rods and iron, or iron
alone. This is quite feasible, bearing in mind that the conductivity of common plastering, compared
with firebrick or building brick, is as 26 to 66, and that an ordinary plaster ceiling on metal lathing,
with the iron well embedded, will resist an inten.se heat for a considerable time.

Plastering in Germany is usually done on reeds instead of wood laths. Plaster slabs have lately
been introduced, and are used to a considerable extent for internal jjlastering. The Germans
manufacture fine Portland cement. About two decades ago a number of London plasterers were
sent to Berlin to construct concrete houses and plaster house fronts with Portland cement. Since
then the German plasterers have been fairly proficient in the manipulation of Portland cement.

It has already been mentioned that the German Government offered valuable prizes for the
best method of indurating plaster casts so that they would resist the weather, also for the best kind

No. 180. — Plaster Cornices (Modern), by K. .Schirmer, Berlin.

of materials and method of using same for e.xterior plastering. The methods are described here-
after. The annexed illustrations are good examples of modern German [blaster work. Plate LI.
shows a centre flower, partly oval in outline, with a bold design and effective modelling. Illustrations
Nos. 179 and 180 show portions of a plaster ceiling and two cornices, and Xo. iSi a wall panel.
These are taken by photography from the actual casts.*

German Mortar. — Some years ago the "Verein zur Beforderung des Gewerbefleiss in
Preussen" (Society for the Promotion of Prussian Industry) offered a prize for the best composition
of plaster for brick walls. The conditions imposed at the time were — (i) That the composition
should not be affected by the weather, and present an even smooth surface when applied, becoming
neither cracked nor loose by exposure to sun or frost ; (2) That the composition should admit of a

* They are reproduced from a series of excellent plates, published under the title of " Plastische Ornamente,"
designed by Robert Schirmer, and published by Hessling & Spielmeyer, of Berlin : London Agent, B. T. Batsford.

444

Plastering — Plain and Decorative.

uniform durable colour being applied to it, the colour to penetrate either through the whole mass
or at least to a depth of one-tenth of an inch from the surface ; (3) It was further stipulated that
although the application of this composition might somewhat exceed the cost of ordinary painted
plaster, still its use should be cheaper than " stucco lustro." The silver medal of the Society,
supplemented by a money prize of i^'/s, was awarded to Ambroselli, a mason of New Barmin (near
W'urzen), after his plaster composition had been proffered to the Society, and stood a practical
test of several years' exposure to the weather. Before proceeding with the description of its
application, it may, however, be well to remark that no new principles or materials are advocated
in the composition; but on the other hand its application demands great exactness of workmanship
and a careful selection of the ingredients. Moreover, the laying-on process demands that the
wall surface on which it is to be applied be built of hard, well-burnt bricks, free of marl, and
previously thoroughly dried. The materials used are lime and sand, which must be entirely freed

>;o. iSi. — r:,.\STER Wall 1'anf.l (MoijEk.n), by K. Schir.mer, Berlin.

from all impurities by special cleansing, and as the following description will show, three different
kinds are prepared from three qualities of sand. The inventor describes one of its most difficult
applications, namely, the imitations of sandstone dressings, as follows : — The brickwork itself
should be as near as possible to the desired profile, so that the laying on may be done in as
uniform a manner as can be obtained. The wall surface, being previously well damped with water,
is now ready to receive the first coat. This is composed of one-third of well-slaked lime (which
should be slaked not less than a fortnight previous to using it), and two-thirds of the sharpest
sand. After the mass has been thoroughly mixed together, Portland cement is added in the
proportion of one-fourth of the volume, and the first mortar composition, after having thus been
prepared and well mixed, is applied in a wet state to the surface of the wall as evenly as possible.
To prevent air-bubbles or cracks occurring, the different layers should not be applied too rapidly,
and time should be always allowed between the layings on, in order that the mortar may set. The

'■J

}

Austrian Plaster IVork.

445

desired profile having been nearly attained with mortar No. i, a finer mass (No. 2) may now be
laid on. The latter is prepared by adding to 2 parts of lime and 2 parts of fine sand 0.12
parts of Portland cement, and so much of the requisite colouring liquid as is necessary to produce
the desired tint when stirred together with mass No. 2. Two layings on with this second mortar

sagsi

No. 1S2. — Plaster Ceiling of .\ RESTACRANr, Vienna.

will suffice in ordinary work to bring the desired profile to the required form. For very fine work,
however, a third coating is used, which is made of 1 part of the finest sand, I part of
fine-sieved lime, 0.5 parts of fine-sieved Portland cement, with the addition of the requisite
colouring matter to ensure the desired tint when dry. This addendum must of course be

446

Plastering — Plain and Decorative.

determined by experiments made beforehand, which will give the necessary proportion required.
The most complete intermixing of these ingredients is absolutely necessary. It is advisable to
divide the laying-on surfaces into so many days' work, since each portion begun must be finished
the same day, for the reason that the compo.sition cannot be touched u]) after a certain lapse
of time.

The above description of plaster work is interesting and useful, as showing the great necessity
of careful selection, mixing, and manipulation of plastic materials, even of the ordinary kinds for
everyday use. This goes to prove that good and enduring work for exterior purposes can be

obtained by the use of lime and sand (with proper
care) and the addition of a small percentage of Port-
land cement. The colouring matter being a part of
the finishing coat, enables the colour to wear more
uniformly and be more durable than if the surface was
painted. The method of mixing colour with the
finishing coat has for a long time been common in
many parts of England, as is also the mixing of
Portland cement with lime mortar.

Austrian Pla.ster Work. — The Austrian
plasterers execute very good work. In Vienna the

house facades are gene-
rally faced and enriched
in stucco, and the use of
stucco is a handicraft
the workers in which
carry on their trade and
hand down their tradi-
tions from father to son.
The stucco is composed
of white lime, and kept
in water for a consider-
able time before using.
Danube sand of vary-
ing degrees of fineness
is mixed with the ma-
tured lime, coarse grit
being used for the float-

No.

s brought

183.— Plaster Angle Piece, Vienna.

ing (which

out in one coat) and the finest for the fining. The proportions of lime and sand are regulated
according to the class of work in hand and the state of the brick walls. The materials are
not measured but simply mixed by guess-work, the workman judging of its fitness by the
appearance as it runs off his fingers after dipping. Portland cement and hydraulic lime have
been tried, but the plasterers seem unable to make such satisfactory work in these materials as in
those of their grandfathers. Figure work is largely employed, it being used in every situation in
which the human figure can be placed on the external elevation of a building. These stucco and
cement facades stand well, and are coloured with distemper (made and used by plasterers) as soon

Belgian Plaster Work.

447

as they become discoloured by age. This method might be employed for most of our old stucco
fronts at home. They would look brighter and cleaner. Women, mostly barefooted, are employed
as plasterers' labourers in Vienna.

The Government encourage the advancement of art and science. The Museum of Applied Art,
with its Technical Art School, built in 1870, has special modelling and plaster-casting rooms. The
fa(jade is enriched with sgraffitto and majolica
medallions, showing heads of celebrated artists and
art workmen. Vienna plasterers are also excellent
workers in scagliola.

In 1886 the Alpine Steel Company, near Vienna,
purchased the Austrian rights of one of my artificial
stone patents, and I sent several London plasterers
to Austria to instruct their workmen in the patent
process for working Portland cement and slag. The
annexed illustrations are examples of modern Austrian
plaster work. No. 182 shows the plan of a ceiling
of a restaurant, Vienna, designed b)' F. Schventhaler;
No. 183 shows an angle piece in a private mansion ;
and No. 184 shows a part of an exterior column.

Belgi.\x Plaster Work. — Belgian plaster
work is somewhat similar to the French. They use
carton-pierre and fibrous plaster for many of their
decorative works. Portland cement is largely used

for artificial stone and paving work. A mixture of

lime, ashes, and sand, termed "Cendree de Tournay,"

is used as a hydraulic mortar. Belgian modellers

are excellent designers, and produce some fine work.

Illustrations Nos. 185 and 186 show pilaster panels

from Brussels. During the last two decades there

have been several invasions of Belgian plasterers to

London. They were employed on the decorative

plaster work at Terry's, the Court, the Garrick, and

other London theatres. They were also emploj-ed at

the Tivoli, in the Strand, where they executed the

fibrous plaster work of the auditorium, dining-rooms,

and bar ceilings. The principal dining-room is called

the Palm Room, and palm leaves are predominant

in the fibrous plaster ceiling, which is of a pendentive

character. The auditorium ceiling is of an Indian

character. The modelling is creditable, but the fibrous

work is indifferently made and fixed. The joints are coarse, and showed signs of opening before

the work was painted. Some of the main mouldings are run in situ in the solid. The method

and finish of this part of the work would not be passed by the most tolerant clerk of works, the

mouldings being of a weak nature and more or less wavy. The amount of material wasted was

nearly equal to the amount used. A curious feature in their tools was a substitute for the hawk.

No.

84.— PoRTio.N OF .\N External Coi.vMN, Viexn.\.

44S

t
S^'^

^^;

fii I'

-M.'»

Vf^

:*':

.)?,

K'l

I 'M

i'.M

No. 185. -Pilaster Panel iro.m
Brussels.

Plastering— Plain and Decorative.

This tool took the form of a diminutive
hod, ha\ing a short siiank with a spur-
shaped end, which fitted and rested on
tlic plasterer's leg just above the knee.
When this hod was charged, the stuff was
pushed out with a trowel on to the part
to be plastered. This system is slow and
laborious, and not so workmanlike as using
a hawk.

It is a remarkable fact, in connection
with this foreign competition, that an
evening newspaper containing a descrip-
tion of the Tivoli, after giving a glowing
account of the building, stated that the
fibrous ]}laster work was given to a Brussels
firm, as English plasterers could not do
tiiat kind of work. It is needless to say
that this is directly opjDosed to facts, and
is not onl)- a libel on British employers
and employees, but an insult to British
intellect. The only thing in which the
British could not compete was the price.
Hut when one thinks of the miserable
wa)- that the I^elgian workmen herded
together, and the scant, coarse, and cheap
food that they existed on while here,
there is little honour or fair competition
in the undertaking. It is worthy of note
that no technical papers, in their descrip-
tions of the building, gave such state-
ments. It may be owing to the confined
circulation of the c\ening paper that the
unjust remarks escaped notice b>- trade
journals. In flat contradiction to the
statement as to the abilit)' of English
workmen I ma}- adduce the following fact.
When the building was nearly finished,
another architect was appointed to com-
plete the work, and he had a small
portion of the fibrous plaster work done
by Messrs G. Jackson & Sons. This work
is the ceiling of the entrance hall leading
to the grand staircase. And although it
is onl_\- a small ceiling, \-et the work is
artistic, sharp, and of sound workmanship,

■k v"*** ^' '*^'

"'t

■■^'

f' Jj

f^t

.V'it

•fm

Vjiffi

t-.i >■

No. 1S6. — Pilaster Panel i-rom
Brussels.

Russian Plaster PVoyk. aa9

will bear close inspection, and compare favourably with the Belgian work. This fact is supplemented
by numerous and excellent works in fibrous plaster which are to be seen in many of the principal
mansions and public buildings throughout Great Britain and Ireland. These works were executed
by British workmen long before the invasion of Belgian plasterers. These facts should be borne
in mind by those who frequently declaim about foreign competition and the inaptitude of their own
countrymen. Nor should it be forgotten that at the Paris Exhibition of 1889, where there were such
an assemblage of buildings in most modes and styles of architecture in every land under the sun,
in which the skeletons were mainly constructed with iron or wood and clothed with plaster work
executed by plasterers from many climes, few of the plaster works could compare with, and none
excel, that done by British plasterers.

Russian Plaster Work. — The use of plaster work in Russia is somewhat limited, as in the
country and the smaller towns wooden buildings are still in a large majority. The introduction of
decorative plaster work is said to be due to Vladimir, who built Vladimir and other towns, and
invited artists and craftsmen from Greece and Italy in the eleventh century. Kiev, once the
capital of Russia, had its principal edifices decorated with plaster work. Ivan III. imported many
foreign artists for the embellishment of Moscow, which was the capital, 1490. Peter the Great
engaged artists and artificers from all the art centres in Europe to decorate buildings in St
Petersburg, the new capital, founded in 1703, and the most important works in plaster have been
done b)' or under the supervision of foreign artists. There are numerous limeworks on the
banks of the Ishora and in the Peterhof district. There are also several Portland cement factories
in various parts of the country, and the output is increasing )-early. A similar industry is the
manufacture of plaster from gypsum. There are several large factories in St Petersburg, where it
is burnt out of the natural gypseous stone. The manufacturers of plaster cast and paint plaster
figures and ornaments themselves. The latter they generally do very artistically. The greater
quantity of the plaster produced is used for stucco work in buildings. Plaster work, like most of
the Russian building trades, is in its infancy, and, like everything else of immature age, it is liable
to weaknesses and errors. It will not be long before the Russian systems will be altogether
revolutionised, and then when Government and people walk hand in hand, with no ulterior object
in view than the practical good of the country, all those industries which are founded upon its
natural resources will rise and flourish.

CHAPTER XVII.
TERRA-COTTA.

Terra-Cotta Work— MoDFXi.iNf:— Model Making— Moulding— Pressing— Drying— Firing— Fixing.

Tekra-Cotta. — The literal meaniiii^ of the words " terra-cotta" is cla\- baked, the material being
clay previously modelled or moulded and pressed into form, and then burnt in a kiln. The date of
the first use of terra-cotta is lost in remote antiquit)-. Antique specimens have been discovered that
after three thousand years are nearly as perfect as when first made. This proves the durability of
terra-cotta, and also that the old specimens in the form of vases, statuettes, panels, and other
varieties of modelled and architectural decorative work, stand the ravages of time better than .stone,
marble, or bronze. The marbles and bronzes found with the terra-cotta were crumbled and
cankered. Pliii)^ mentions a dish or vase made for the Emperor Vitellius that cost a million of
sesterces, which in our money would be over ^^4,000. He also states that it was the custom to
make figures of the gods in clay, and that many such figures remained in his time. The remains
of Pompeii and Hcrculaneum contain some fine s]:)ecimens of modelling in the ends of the baked
clay roof-tiles, vases, statuettes, and other works of art.

This material was greath" used for vases, and by the aid of Greek art, which has transformed
the commonest of materials, clay, into a durable substance having rare form and beauty, some of
these va.ses are so valuable that in recent times they ha\e been sold for more than their weight in
gold. The greater number of them have probably been turned or thrown on a potter's wheel. The
potter's wheel is mentioned in Scripture, and is said to have been invented in China, and to have
passed into Eg)-pt, Greece, and Arabia. The potter's wheel now in use is nearly the same as that
carved on the tombs in Egypt. Some of the old vases have c\identl)- been moulded, and the
ornamental work drawn while the clay vase was yet damp.

Terra-cotta ware, such as \-ases, plaques, &c., is first " thrown " on the potter's wheeL which
gives the general form required. After being dried, it is turned on a lathe to the design required,
the decorative lines, " runners," or coloured lines being run round it while in the lathe. The
coloured |)igments are not water or oil colours, which would perish in the fire, but minerals. .Artistic
designs are also painted or transferred on the vases, &c., before they are submitted to the kiln.

Sarcophagi of terra-cotta, ornamented with bas-reliefs and with recumbent figures of the
deceased, are to be seen in the British Museum. Plin_\' states that V'arro and others directed that
their bodies when dead should be deposited in baked clay or earthenware. Terra-cotta vases, richly
decorated with scenes from real life, were used on the Dipylon tombs at Attica, B.C. 700. Finely
decorated vases were used in Etruria, H.C. 500. Homer states that the dead were cremated, and
that the tombs were huge mounds and vases. The \-ases were decorated with scenes from e])ic
mythology — Perseus and Medusa, Herakles and Nessos, &c. Cicero says that Demetrios, K.C. 310,
abolished the use of groups of figures on tomb vases. Mr Flinders Petrie found manj' terra-cotta

Terra-Cot t a Work. 45'

vases and statuettes in trenches at Naucratis. Mr Gardiner has deciphered the name of Rhcecus
on one of the statuettes. Rhcecus was probably the same sculptor who was in antiquity spoken of
as having worked in the Egyptian style, and who was at the same time, with his son Theodoras, one
of the originators of the production in Greece of statues of divinities. On a vase was found the
name of Sappho, whose brother, if not herself, journeyed to Naucratis.

The Chinese, Persians, Babylonians, and Indians were great workers in terra-cotta, and even in
Central and other parts of America specimens have been dug up. In Italy, some of the principal
towns have buildings (erected between and during the twelfth and si.xteenth centuries) adorned with
rich terra-cotta. Fine old foreign examples are to be seen in the South Kensington Mu.seum.
Bernard Palis.sy brought terra-cotta to great perfection, and his particular make is named after him.
Elers of Nuremberg came to England in the seventeenth century, and started a kiln near Burslem.
He afterwards removed to Lambeth, where he founded the first kiln there. A fine collection of
works of art in artistic pottery and terra-cotta, by Flaxman and Wedgwood, was founded at
Burslem and Etruria over a century ago. Lambeth was the first, and is still the London home of
terra-cotta.

Terra - cotta works were founded at Lambeth about a century ago by M. Conde. The
principal modellers in terra-cotta at that time were Rossi, who modelled the caryatides and other
adornments at St Pancras' Church, London ; and Bub, who modelled the figure frieze on the facade
of Her Majesty's Theatre, Haymarket, and the statuettes on the cornice, and in the tympanum of
pediments in Regent's Park.

On an old house at the corner of Belvidere Road, Lambeth, there is a small oval artistic panel,
marked " Conde's Row." This house was once the showroom of M. Conde. Here Conde, the great
Flaxman, and John Bacon, the celebrated sculptor, worked.

Fulham Pottery, some centuries old, now exists in prosperity. From this pottery sprang
Doulton's famous Lambeth Pottery Works, Mr Doulton having served an apprenticeship here. Mr
G. Tinworth, by his high-class artistic modelling and designing for terra-cotta, has obtained a world-
wide reputation for the Doulton firm. Messrs Stiff & Son turn out sound and artistic work. Mr
Pulham, formerly a modeller, produces some fine terra-cotta works. Messrs W. Cubitt & Co. stand
alone as being the only builders who also execute terra-cotta work. It was at Cubitt's that I gained
a knowledge of terra-cotta. Columbia Market, erected for the Baroness Burdett Coutts, may be
cited as one of the many terra-cotta works executed by Messrs Cubitt. There are many provincial
firms whose work, for hardness, colour, evenness, and beauty of modelling, will compare favourably
with that of any other country.

Terra-Cotta Work.— Terra-cotta is simply clay cleaned of all impurities, and sometimes
mixed with sand, crushed glass, old pottery ware, and flints. The latter materials are ground and
sifted, and then mixed with the clay in larger or smaller proportions, according to the kind of clay
used and the class of work in hand. Devonshire clay is a fine material for modelling and firing, but
it is not so hard and flinty as that of Staffordshire. It has been said that no country in the world
can produce a clay better suited for terra-cotta than England. The addition of sand or broken
pottery ware to the clay makes the harder terra-cotta, but the unmixed cla\- is usually employed for
fine art. Mixed clay is generally ground in a pug-mill. It is then made into pieces of convenient
size, and beaten or tempered until it is of an even consistency, like modeller's claj-.

Terra-cotta work may be produced direct from the modeller's hands. The models may also be
moulded, and then pressed or cast as desired ; but in either of the three methods the work must be
dried and then finally fired. Great care is necessary in the selection of the clay, and the combination

452

PI a si eying — Plain and Decorative .

of the materials mixed with it. Especial care and experience is required for drj-ing and finall)-
firing, so as to ensure hardness, evenness of line, and uniformity of colour. Une\enness causes bad
joints and unsightly mouldings. The terra-cotta work at the Albert Hall is a distressing example
of twisted and uneven work ; whilst the Natural History Mu.seum, and man)- other buildings in
London and the provinces, are pleasing examples of good terra-cotta work.

TekRA-Cotta ModellinC. — Terra-cotta work modelled direct from the cla)-, while dispensing
with waste or piece moulding and pressing, also permits the work to leave the artist's hands
with all its original freshness and artistic touches. When modelling in this wa>- the artist must
dis])ense with interior wood or iron supports, because as the clay dries round the sujjports it
would crack in shrinking, and consequently the model would be injured. Again, if the supports
were of iron, the intense heat would cause them to expand and melt, and if of wood they would be
consumed, to the utter destruction of the model. A simple way is to model the work solid, and
then with a wire tool or a knife to make a thin section down the back, or any other part that is
usuall)' not seen. Then make a plaster case on the section to support it, and insert a wire and cut
out the section, which will then come away with the case. Lay this aside initil wanted. Then cut
or scoop out the interior, leaving a uniform thickness of clay in all parts of the model. The thickness

\-arics from i inch to 2 inches, according
to the size and purpose of the work.
The edges of the back section are then
damped and brushed over with clay water
to ensure adhesion, and the piece replaced,
the joint being concealed by being worked
over. Models that are not open are pierced
with small holes in unexposed parts to allow
the steam to escape. The model is placed
in a drying-room until thoroughly dry. It
is now ready for the kiln. Some artists
wash the whole surface of the model with
a thin solution of clay, which gives a fine
bloom. It is sometimes necessary to cut off the arms, legs, draper}-, or other accessories to allow
the work to be made hollow, or if the model has to be piece moulded for further casts. The joints
are then fixed on with well-tempered soft claj-. These parts are supported in position with props
until the whole model is dry and firm.

Decorated blocks for architectural purposes, or repeated work, are made and then modelled in
the same way as used for plaster and concrete work. The annexed illustration (No. 187) shows
design of two keystones and one antcfix in terra-cotta. This antefix is enriched with sea-horses
and foliage. The upper part is known as the Greek honeysuckle. AntefixjE are upright ornamental
blocks placed at intervals on the cornice along the side of a roof to conceal, or rather terminate, the
ridges formed by the overlapping of the roof tiles. Similar ornaments, or a statue, which are placed
on the apex of a pediment, are called acroteria.

Model M.vkixg. — Model making is an important part in the formation of terra-cotta work.
In the first place, the architect's design should be given to the general foreman, or a draughtsman
who has a knowledge of solid geometry combined with a practical knowledge of bonding and jointing
of stone work. The drawings are usually made to a i-inch scale, each elevation being kept separate.
A tracing of the i-inch scale should be submitted for the architect's approval before the work is begun.

No. 1S7. — Keystones and Antekix.

Motddiiig and Pressing. 453

The dimensions for working, or full-size drawings, are taken from a " shrinkage," or " clay "
rule. This rule is 26 inches long. One side is divided into 24 equal parts, each part being again
divided into 8 parts, similar to an ordinary rule. The other side is divided into 24 ordinary inches,
leaving an inch blank at each end. If there are no full-size drawings to work from, as is often
the case, for plain simple work, the models are made to the desired size by the aid of the
"shrinkage rule" from the figured drawings. It will be seen that the clay ".squeeze" (produced
from the piece mould of the model), which measures i foot by the shrinkage rule, will, when burnt,
measure i foot by the ordinary rule. This combined or shrinkage rule is often blamed for the
mistakes that sometimes occur through the forgetful or over-anxious workman. To prevent these
mistakes, which cause vexatious delays and loss, it is best to check the measurement of all models
before the)^ are moulded. All clays have not an equal shrinkage, and it is necessary to have a
clay rule for each kind. Here again, to prevent mistakes, the measurement of the models should
be checked by the setter out. Blocks of different form or size should have separate full-size or
" clay drawings." Plaster is the usual material for model making.

Moulding. — Moulding for terra-cotta work is similar to plaster piece moulding for plaster
or concrete casting, dry moulds being the best adapted for speedily obtaining good sharp
impressions, consequently the less plaster there is in the mould, the less moisture, and the more
readily the mould dries. Reverse moulds may be advantageously used for many parts of terra-
cotta. Moulds for terra-cotta require no seasoning, but are simply dried. Each mould should
be numbered and initialed by the maker, as a means of identification.

Pressixg. — This is done by a workman technically termed a " pressor." He should be
supplied with a duplicate order form, on which thei^e is a sketch of the block, the quantity required,
the number of the mould, the name or key letter of the job, and the date. This saves waste and
confusion, and affords an identification for the work and the worker. The presser cuts balls
of prepared clay with a wire into sheets of the desired thickness, and smooths the surface by rolling
or pressing it on a bench. He then presses it on the face of the mould, repeating this until the
whole mould is covered to the necessary thickness, which should be as uniform as possible. The
casts are made hollow to allow for contraction when being fired, as the heat that has penetrated
the thin parts has only partially penetrated the thicker, and consequently the contraction is
unequal, and the cast liable to be contorted, or fly into pieces. Care must be taken, when
pressing, that all the clay pieces are thoroughly incorporated with each other. If not, blubs, creases,
and patches will show. When the whole surface is equally covered, clay partitions are formed from
side to side, or from end to end, or both ways, so as to form internal supports. It is then at once
taken out, and if plain work, the presser may take off the seams and clean the work up, but if the
work is of an ornamental nature, the seams are taken off, the whole cleaned up, and the foliage
undercut by a good shop hand. If the work is of a highly artistic nature, the modeller puts on a
few original touches, and strengthens the dull parts and general effect. By this means a squeeze
may be made to have all the spirit, and much of the merit, of an original model.

The mould after being used a few times becomes damp, which prevents the casts from leaving
cleanly and expeditiously. In such a case the mould is put aside for a time to allow it to dr)-, or
for the purpose of preventing the adhesiveness the mould is dusted with finely sifted flint glass
powder. In some instances a fine clay is used for the face surface and a coarser qualit\- for
backing up to the desired thickness. Great care is required when pressing mouldings to ensure
straightness of the members, and intersections at the joints. The blocks and their mouldings
should be pressed so that the clay is of a uniform thickness, in order that the shrinkage may also

454 Plastering — Plain and Decorative.

be uniform. When pressing a number of blocks to make up a length of straight moulding, or
circular pieces for arches, the several pieces when nearlj' dry should be laid in the same position as
they will appear when finally fixed, and then the moulding regulated at the joints and the whole
made true and Unable. The blocks are then numbered, and when dried the several joints can be
tested, and any defects made good.

Mitres. — "Stuck joints" is a cheap way of forming internal and external mitres, returns,
&c. The clay mouldings are cut to the desired angles, and the joints are keyed with a knife or a
rough drag. Soft clay is then laid over the joints, and the two pieces rubbed together. This
method is used to save the cost of making a model and a piece mould ; but the work is not so
sound as if pressed in one piece, and the cost, if less at first, is generally greater in the end, as a
large number of stuck joints give or open when subjected to the ordeal of firing, or if they pass this
ordeal, they are often rent asunder by the trowel when being fixed.

C.-VSTING.— This method is only used for small work, such as small figures, vases, brackets,
&c., and is only resorted to where numerous and cheap copies of work are required. A cast is in
every way inferior to a squeeze. The moulds for terra-cotta casts are made of common plaster, or
fine and coarse plaster mixed in equal proportions, and when gauged soft by using a liberal amount
of water, it forms a porous mould, which absorbs the water rapidly from the cast. The cast is
formed by making a smooth solution of fine clay, made about the consistency of cream. This
solution is poured into the mould, which being porous, absorbs the moisture, and the solution
adhering to the mould sets, leaving a coating of clay on the inner surface. This process is repeated
until a sufficient thickness is obtained. The mould is then taken off, and the cast cleaned up,
dried, and fired, as already described. All work taken out of a mould, whether pressed or cast, is
usually termed casts.

Drvin"G. — The drying of terra-cotta casts requires care and regular attention to prevent them
from warping, also to stop any cracks that may appear. The casts are placed in a drying-room, or,
if the weather is good, in the open air. The drying should be regular. Sudden or irregular drying
tends to twist or crack the casts. Long and open casts are liable to twist in drying. This may be
partially, if not whollj', prevented by forming temporary clay struts on interior and exterior
parts where most effective. When all is dry, the struts are cut away. Narrow interior struts can be
left in.

Firing. — The kilns or furnaces vary in size from 4 or 5 feet in diameter up to 20 feet. They
are built of fireclay brick, and bound with iron hoop to prevent them bursting when red-hot
within. The casts to be fired are packed in fireclay bo.xes, and stacked one above the other.
This requires great care, as the casts may get damaged, or the heat may not get to all the casts,
causing unequal burning, and consequently damaged work. When the kiln is full, the doorway is
bricked up, and further secured by iron bolts. The fires are then lighted, and continued for three
or four days. The processes of firing and cooling last from one to two weeks. A large kiln
takes about a week to cool. The casts must not be taken out until cool, as the air would crack
them. The firing is an important and anxious process, particularly if the works to be fired are
originals, or of a delicate nature, requiring a certain amount of intensity and exposure, and no
more. The degree of heat applied will render the work more or less hard, but excessive firing will
vitrif}' and discolour the surface. When the works are taken out of the furnace, they will be found
ro have shrunk uniformly about one-twelfth, and to have changed colour, the final colour being one
of the various shades of red or yellow, depending on the kind of clay used for the model. In
some instances, in the case of a special model, it is placed in the furnace, and a firebrick wall built

Fixing. 455

up round it, to prevent the flames reaching the model. For small work, a cover, commonly called
a "sagger," is used for the same purpose. In some kilns small pats of clay are put in with the
other work, and at intervals an opening is made to allow a pat to be withdrawn, as a test to see
whether it is properly or fully fired. Terra-cotta work in a greater or less number of repeated
designs for architectural constructive or decorative work is often required, and the work, to ensure
success with the least possible waste, must be dene in a proper routine and method.

Muffle terra-cotta kilns are generally used for large work. Some are round in shape, and
some are oblong. Their size varies from lo to 13 feet in diameter by 10 to 17 feet
in height. The muffle flues are about 5 inches spacing, and the thickness of muffle varies from
2 to 3 inches. The heat has an up-and-down draught, the heat rising upwards over the muffle
flue, over the muffle crown, and downward through the centre flue (or chimney), thence under the
floor. From there the heat passes upwards in flues built between the furnaces in the muffle space,
and then into the dome on the side of kiln. There are six or seven furnaces to a kiln. In a good
kiln three qualifications are essential : good combustion, even circulation, and durability of
construction. In the production of one ton of terra-cotta ware nearly 700 lbs. of water, or more than
80 gallons, are required. Nearly 70 gallons of this moisture have to be evaporated in the process
of drying, and the final 10 gallons pass off after the work is placed in the kiln in a form known as
water-smoke. One of the hardest colours to obtain uniformity in the tint is the elegant buff, and
to secure this rich pleasing colour in terra-cotta requires long burning and a perfect knowledge of
firing, as well as a thorough acquaintance with the clay and its behaviour in the kiln. The
principal kiln at \V. Cubitt & Co.'s was designed by R. Green, a London plasterer.

Fixing. — Terra-cotta is usually fixed \>y masons. Hollow casts for constructional work are
rendered stronger by filling them up with breeze concrete. The breeze should be freed from
all small pieces of coal or other foreign matter, which are liable to swell and burst the shell.

Tekra-Cotta Trade. — Terra cotta is now extensively used throughout the country for
constructive and decorati\e building purposes. The production of the beautiful facina ware and
general terra-cotta affords a considerable amount of work for modellers, model makers, and piece
moulders ; but however good these workmen may be in a plasterer's shop, they would at first
feel strange in a terra-cotta manufactory. It is therefore hoped that the above instructions will
prove of assistance to modellers and plasterers in their maiden efforts on terra-cotta.

CHAPTER X\'III.
CONCRETE.

Historical— B6T0N Agclomrri^: — Fine Concrete— Matrix— Aggregates — Compound and Fireproof
Aggregates- Sand and Cement — Voids in Aggrec;ates — Crushing Strength of Concrete —
Water for Concrete— Gauging Concrete— Ramming Concrete— Thickness of Concrete Paving
— Concrete Paving— Metallic — Eureka — Eureka Aggregate and Quantities — Levels and
Falls— Screeds and Sections— Laving, Trowelling, Grouting, and Dusting— Temperature—
Non-Slippery Pavements— Grooved and Roughened Surfaces— Stamped Concrete— Expansion
Joints— Washing Yards — Stable Pavements— Brewery Pavements— Dairy and Food Factory
Pavements— Staffordshire Stone Paving— Petrura Paving— Summary of Paving "in Situ"—
Concrete Slabs— Mosaic -Concrete Mosaics— Roadways.

Historical. — The word concrete is of Latin origin, and signifies a mass of materials bound or
held together by a cementing matrix. The Romans used concrete B.C. 500. They made good
use of lime concrete both in the construction of buildings and roadways. " Roads," says Gibbon,
" were the most important element in the civilisation of ancient Rome ; and the cost of the
Appian Way was such as to entitle it to the proud designation of ' Regina Viarum ' (the Queen
of Roads)." The Appian (the oldest of the Roman highways) was commenced by Appius
Claudius Caius, when he was censor, about three centuries before the birth of Christ. It extended
from Rome to Capua, whence it was subsequently carried on to Tarentum and Brundusium.
Antonio Nibby, an archseologist of the highest authority, states that the Appian Way had an
admirable substructure, with lime concrete materials superimposed, and large hexagonal blocks of
stone laid on the top of all. The Romans built concrete aqueducts, often several miles long, to
convey water to cities. The Palace of Sallust, the historian, was built about B.C. 50, and was
frequently used as a residence by most of the emperors until as late as the fourth century. It
was partly burnt by Alaric in the year 410. This once magnificent edifice was erected on a
strange site, partly in the valley at the foot of the Ouirinal Hill, and partly on the top of the
hill. The latter portion of the palace, which was of great extent, has been almost wholly destroyed
by the builders -of the modern boulevard. The walls, which were thick and high, were most
valuable examples of the Roman use of concrete, unfaced b)' brick or stone. There is still visible
evidence, in the form of impressions left on those walls, which clearly demonstrates their method
of casting walls in situ by means of wood framing. Rows of timber uprights, about 10 feet high,
6 inches wide, and 3 inches thick, were fixed along both faces of the intended wall. Boards about 10
inches wide and i \ inches thick, in suitable lengths, were then nailed horizontally along the uprights,
thus forming two parallel wooden walls, into which the concrete was laid and rammed until the
space between the boards was filled to the top. When the concrete had set, the wood framing was
removed, and refixed at the top of the concrete, the whole process being repeated until the wall
was raised to the required height. This concrete was far more durable than brick or stone. The
jerry-builders of modern Rome had no difficulty in pulling down the stone wall of Servius, but

Ancient Concrete. 457

the concrete walls required the use of dynamite to complete their destruction. After withstanding
the wear and tear of man>' centuries, and the repeated onslaughts of the Goths and Vandals, it was
left to the nineteenth-century speculative builder to destroy those interesting remains.

The use of concrete for floors and roofs is of great antiquity. It was emplo\-ed for this
purpose by the Romans in the time of Julius Cae.sar. Professor Middleton, in his first book,
" Ancient Rome," states that the whole of the upper floor of the Atrium Vesta is formed of a
great slab of concrete, 14 inches thick, and about 20 feet in span, merely supported by its edges
on travertine corbels, and having no intermediate supports. In his second book, " The Remains
of Ancient Rome," Professor Middleton mentions that the Romans used concrete for the construc-
tion of the Pantheon, which was erected about the time of Christ. A curious and apparently
unaccountable feature as regards practical purposes is that the concrete is faced with bricks, which
were faced again either with stucco or (in special cases) with marble veneer. The Professor gives
a sketch showing the exterior facing and the section of a wall of this kind, the entire mass being
compo.sed of concrete, except a facing of thin bricks, triangular in plan, with the points inwards.
As the author observes, these bricks could not possibly be intended as a matrix for concrete, as it
would not have withstood the pressure of the latter while in a wet state. It must therefore have
been necessary to retain the brick and the concrete with an e.Kternal timber framing, as in the case
of unfaced concrete. There could be no gain of strength or other benefit to compensate for the
time expended setting the brick skin. The dome of the Pantheon is 142 feet in diameter and 143
feet high. This is also formed with brick-faced concrete. It has often been described and
even drawn by various authors as essentially a brick dome. Professor Middleton remarks there
must have been verj- elaborate construction of centring for this and other massive concrete
vaults. He states they employed a method, which has become common of late, to avoid the
necessity of building up the centring from the ground. They set back the springing of the arch
from the face of the pier, so as to leave a ledge from which the centring was built, the line of the
pier being afterwards carried up until it met the intrados of the arch, leaving it a segmental
one. The Professor also found signs of timber framing for walls in the remains of the Golden
House of Nero, under the Therm.-e of Titus, where, he says, "the channels formed by the upright
posts are clearly visible. These upright grooves on the face of the wall are about 6 inches wide by
4 inches deep, and they were afterwards filled up b\- the insertion of little rectangular bricks, so
as to make a smooth unbroken surface for the plastering." This method is difficult to understand.
According to the present practice, the supports would be fixed outside the line of wall surface, and
leave no spaces to fill in afterwards. He also mentions a striking example of the tenacitj- of
good concrete in the Therm.-e of Caracalla, at a part where a brick-faced concrete wall originally
rested on a marble entablature supported by two granite column.s. " In the sixteenth centur>-,"
he sajs, " the columns and the marble architrave above them were removed for use in other
buildings, and j-et the wall above remains, hanging like a curtain from the concrete wall over-
head." This proves that the Romans bestowed as much thought and care on the materials and
their composition as they did on construction. Professor Middleton notes that the larger pieces of
aggregate in the concrete, which are not close together, are so evenly spaced apart as to lead to the
conclusion that they must have been put in by hand, piece b)- piece.

Dr Le Plongeon, during his ex[)lorations in Peru, found many remains of mud concrete
walls. Although they were built many centuries ago, they have proved sufificienth- durable to
exist until to-day. The materials were placed between two rows of boards, and well beaten, and
the exteriors were sometimes decorated with plaster work. Thus it appears that the Peruvian

4S8 Plastering — Plain and Decorative.

builders of the period of the Incas anticipated by centuries the method (but not the material) of
our modern concrete building. Le Plongeon's researches conclusively establish the fact that these
Indians were masters of concrete buildinjj and plastering. The walls of the fortress of Ciudad
Rodriijo in Spain are built of concrete. There are over 12 miles of arches and tunnels constructed
with concrete in the Vanne Aqueduct, which supplies Paris with water. One of the arches over
the Orleans Road, in the Forest of Fontainebleau, has a span of 125 feet without a joint, the
arches and the water pipe or tunnel beiuLj entirely composed of beton, made with Portland cement,
hydraulic lime, and the sand found on the spot. Concrete blocks wei;4hing over 20 tons were used
in the construction of the Suez Canal, 300,000 tons of these blocks being required at Port Said alone.
The Albert Docks are made of concrete laid in situ. Douglas Harbour in the Isle of Man, and
the Aberdeen Docks, are built of concrete blocks, and also the harbour of the North Sea entrance
to the Amsterdam Canal. These are all lasting examples of concrete work.

Tall, Drake, Henley, Potter, and others have built entire houses monolithically with concrete.
Concrete is the best known material for reservoirs, for which it is safe and sanitary. One of the
finest examples is the Hanchurch Reservoir, Staffordshire, built by the Patent Construction
Company, and designed by G. D. Harrison, C.E., Hanle)-. This reservoir is 225 feet long, 156 feet
wide, and 21 feet deep. There were about 20 acres of concrete flooring laid at the Paris Exhibition
of 1878. Mr Lascelles, of London, erected a house with concrete slabs at the same Exhibition, and
was awarded a gold medal and the Cross of the Legion of Honour. The house was designed by
Mr R. Norman Shaw, R.A. The pavement in " Old London," at the South Kensington Exhibitions,
was laid with metallic concrete. It was estimated that this pavement was traversed by no less
than 33,000,000 people, in addition to heavy loads, yet when taken up, when the site was required
for the Imperial Institute, it showed no signs of deterioration or even of perceptible wear. The
pavement and the stairs in the subway from the South Kensington Stations to the Exhibition
Grounds, also formed in situ with metallic concrete, over which 27,000,000 people passed in three
)-ears, look as strong and as durable as ever, and show but little trace of wear. Owing to the
great sanitary effect and jointless surface of concrete, it was used for paving the stables at
]\Iarlborough House, the London home of the Prince of Wales. This work, and that at " Old
London " and the South Kensington subway, was executed by Wilkes' Patent Metallic Flooring
and Eureka Concrete Company under my supervision. Important works in metallic concrete
paving have also been executed for H.M. War Office, the Metropolitan Board of Works, Fire
Brigade Stations, Railway and Tramway Companies, Vestries, Corporations, &c. The countless
works executed by Messrs Wilkin.son, Stuart, Cordingley, Ward, the Victoria Stone Companj', the
Imperial Stone Company, the Patent Paving Company, the Metallic Flooring and Artificial Stone
Company, and others too numerous to enumerate, furnish indubitableproof of the value and suitability
of concrete for architectural works and paving purposes. Besides the unquestionable durability of
concrete, it also possesses fire-resisting and waterproof powers of the highest degree. Construc-
tional works formed with concrete carefully made and applied may be considered absolutely
fire-resisting and damp-proof; in fact, in these respects concrete has long since passed the
experimental period, inasmuch as numerous tests, under the most trying and adverse circumstances,
attest the superiority of this material for sanitary and durable work.

BetoN AggLOM£r£. — The best concrete in France is that made under Coignet's system of
" bdton agglomere," and has been used with great success in the construction of various large and
important works. In Paris many miles of the sewers have been formed of this material ; and a
church in the Gothic style, from the foundations to the top of the steeple (which is 136 feet high), is

Fine Concrete. 459

entirel}- formed of btton. The work was prosecuted without cessation for two years, and was
exposed to rain and frost, but has not suffered in the slightest way from extremes of temperature.
The strength of this material for constructive work may be judged by the thickness, or rather
want of thickness, in the construction of a house, six stories high, having a Mansard roof — cellar,
19 inches; first story, 15 inches; second story, 13 inches; and diminishing I inch every suc-
cessive story, so that the sixth story was 9 inches. The cellars have a middle wall from back
to front, from which spring flat arches having a rise of one-tenth of the span, the crown being 5
inches thick, and at the springing 9 inches, which formed strong dam]>proof and fireproof cellars.
There are many houses in Paris constructed of this material. It has been used in London in the
construction of sewers, &c. This concrete is composed of Portland cement, sand, and lime.
Hydraulic lime is used for sewers and waterworks, and common lime for ordinary work. The
lime is used in a powdered state. The whole of the materials are mixed in a dr\' state by hand,
and afterwards gauged in a specially made pug-mill. The least possible amount of water is added
by means of a fine jet while the pug-mill is in motion. The mi.xture is then spread in thin layers,
and beaten by rammers formed of hardwood. The quantities for coarse work, where a fine face is
not required, are — Portland cement, i part ; common lime, A part; gravel, 13 parts; coarse and fine
sand, 6 parts. And for sewers — Portland cement, i part ; h)-draulic lime, I part ; sand, 6 jjarts.
And for external work of good quality — Portland cement, i part ; lime, \ part ; sand, 7 parts. The
above proportions are all by measure. Specimens of Coignet bcton at two years old have attained
a crushing strength of 7,400 lbs. to the square inch.

Fixe Conxrete. — No book on plastering would be complete without a description of the
methods for working " fine concrete " (here termed " fine concrete " to distinguish it from rough
concrete as used for foundations, &c.), which is now coming into general use for paving purposes,
staircases, and constructive and decorative works for buildings. Floors, roofs, and similar works
which are finished with fine concrete, being within the plasterer's province, also demand description.
The proper manipulation of the plastic materials, which is imperative for sound concrete, is
undoubtedly plasterer's work. The higher branches of concrete work, for architectural construc-
tion and decoration, embrace model-making, modelling, piece-moulding, and casting. Concrete
construction is therefore essentially a part and parcel of the plasterer's art and craft. The con-
struction of concrete staircases in situ affords a striking example of the necessity of employing
plasterers. Only a plasterer can manipulate the materials correctly, make the nosing mitres sharp
and true, and set the soffits of the stairs and landings, and form a true arris at the stringing,
whereas the non-plasterer leaves the work uneven, rough, and unsound. The non-plasterer can just
manage to spread the stuff laid on the ground for him when laying paving, but he is entirely lost when
the stuff has to be taken up on a hawk and laid with a trowel on an upright or overhead surface.
He then gets upset, or rather he upsets the stuff. The non-plasterer possibly ma\- have been an
unfinished apprentice, or a dunce at his former trade, hence his tr\ing another. These remarks
are not caused by an)- hostility to other trades, but are inspired by the fact that many failures in the
better class of concrete are due to the non-plasterer's incapacity in working, and his lack of know-
ledge of the materials. Portland cement concrete pavements were first used about fifty years ago.
Its introduction, improvements, and .subsequent rapid strides for paving, and in the construction
of staircases, cast and made in situ, are due to plasterers. Mr \V. K. Wilkinson, a well-known
plasterer of Newcastle, was the pioneer of concrete paving in England. Mr P. Stuart, a Peterhead
plasterer, was the first to introduce the well-known granolithic in Scotland. Messrs Cordinglej-, of
Bradford, and J. Greenwood, of Crossbills, both plasterers, were the first concreters in Yorkshire—

46o Plasteriug — Plain and Decorative.

Walker, a Leeds modeller, being the next in the field of concrete. The author, w ithout being
boastful, ma)- fairlj- claim to be the first to conceive the idea of constructing concrete stairs in
situ. There is another class of work done in situ with rough concrete for foundations, houses and
other structures of a monolithic nature, on which, being done with more or less unskilled labour,
further comment is unnecessary. Concrete is one of the best materials for paving the side-
walks of streets, abattoirs, stables, breweries, &c. It is jointless, impervious, non-slippery, and
can be laid with a plain surface or grooved to any desired form. The only objection to paving
laid in situ for streets is that when it is cut to repair or alter gas or water pipes, it is difficult to
make good without the patches showing. This slight defect can easily be overcome b)- cutting out
the whole bay where the patches are, or by forming a movable slab over the pipes.

There has been during recent years some controversy as to the department of the building
trades to which laying concrete paving properly belongs. The claim is undoubtedly upheld in the
strongest way for the plasterers. It will be remembered that this paving was originally introduced
by Mr W. B. Wilkinson, of the well-known Xewcastle-on-Tyne firm, himself a plasterer. The
patents and improvements in the materials and methods of laying concrete paving have been intro-
duced and followed up by plasterers. Metal rollers for indenting concrete surfaces were introduced
by Mr P. Stuart, an Aberdeenshire plasterer. Eureka concrete paving, also the construction of
concrete stairs in situ, were first introduced by the author. A further argument, if one were needed,
to identify the operation as a plasterer's job, is that the tools, skill in which is necessary, are exclu-
sively those of plasterers. The laying trowel and the hand-float are principally used, and none
but plasterers exclusively employ them, no other workman in any branch of the building trades
being habituated to their use. In every part of the world where concrete paving has been used it
has been laid down by plasterers, so that it may be looked upon as their legitimate sphere of work.

Concrete is now extensively used in preference to earthenware for making sewer tubes.
Experience has proved that the acids present in liquid sewage and the gases generated by the
action of fa;cal decomposition do not injure the concrete tubes, but on the contrary tend to
harden them. Among the many unlikely purposes for which concrete has come into use may
be mentioned statuary, vases, fountains, sinks, tanks, cisterns, cattle-troughs, silos, railway sleepers,
platform copings, chimney-pieces, chimney pots, tall chimneys, tombs, tombstones, and coffins,
Concrete is slowly but surely coming to the front as one of the most useful, economical, con-
structive, and decorative materials for works requiring strength and endurance. It may now be
said to be indispensable to the architect, engineer, and builder. Concrete, when properly made
with a Portland cement matrix, and slag or a similar aggregate, is undoubtedly the best fire-
resisting material used in building construction. It can be made thoroughly waterproof and
acid proof, and may be moulded or carved to any design and coloured to any shade. After this
brief historical review of concrete, the practical considerations of modern w^orking by plasterers
claim attention. Before describing the method of working the concrete, a description of the materials,
w-ith their characteristics and application, is given as a preliminary guide and reference. Notes on
some of the most prominent pavings of the present day are also given.

Matri.X. — Matrix is a word used to designate any material having a setting, binding, or
cementing power, such as limes, plaster, or cements. For concrete paving, stairs, floors, or cast
work for external purposes, it may be truly said that there is only one matrix, namely, Portland
cement.

Aggregate. — This is a term applied to those materials held or bound together by the matrix.
Aggregates maj- be fibrous or non-fibrous, natural or artificial. The natural aggregates comprise

Aggregates for Concrete. 4^'

granite, stone, shells, marble, slate, gravel, sand, metal filings, &c. ; the artificial, slag, brick, pottery,
scharff, clinkers, coke-breeze, ashes, glass, &c. ; and the fibrous, slag, wool, coir, fibre, reeds, hair, cork,
tow, chopped hay, straw, shavings, &c. The fibrous aggregates, while being principally of a natural
kind, are generally of a vegetable nature. They are commonly used with a plaster matrix for interior
works. The best aggregates for the upper coat of concrete paving are granite, slag, and some of
the hard limestones. The best and cheapest for the first layer or rough coat are broken bricks, old
gas retorts, clinkers, whin and other stones. Stone chippings from masons' yards and quarries are
cheap and good. Shingle and gravel are also used, but owing to their round and smooth surfaces
they afford little or no key for the matri.x. When found in large quantities and at a cheap rate,
they should be broken to render them more angular, .so as to give a better key. Aggregates are
broken by crushing or stamping machines. In London, the stone aggregate used for casting figures,
vases, and similar ornamental works is generally broken by hand.

Aggregates should be clean, and their surfaces free from mud and dust. Coarse aggregates are
easily cleaned by turning on a strong stream of water from a hose. The aggregates should be laid
on an inclined plane to allow the water and dirt to run off The importance of a clean aggregate
is seen from the fact that briquettes made from washed particles resist a tensile strain from 15 to 20
per cent, higher than those made from unwashed particles, when tested under similar conditions.

Porous Aggregates. — All aggregates of a porous nature or having great suction should be
well wetted before being gauged, to prevent absorption of the water used for gauging the matrix.
A porous aggregate requires more cement than one of closer texture, and is not as strong. Water
has no power to harden or set an aggregate. It is used to render the mass plastic, and to set the
cement. No more than is necessary for this purpose should be used. Sloppy cement will not
attain the same degree of hardness as a firm or stiff gauged cement, consequently it stands to reason
that if the water or a part of it be absorbed by a porous aggregate, it will render the matrix, or that
part next to the aggregate, friable and worthless. This may be proved by gauging a part of neat
cement and spreading it on a brick, and another part on a slate. It will be found that the latter
will set and become hard, whilst the former will either crumble before setting, or partly set, without
getting hard. All aggregates are more or less absorbent, but while the porous kinds will absorb
the water from the matrix, not only leaving the portions in immediate contact with the aggregate
inert, but also weakening the whole body of the concrete, the non-porous have little or no
absorption, water being retained in the matrix, or a portion may lie on the surface of each particle
of aggregate, thus tending to harden the matrix and increase the general strength of the concrete.
It may be thought that these defects are trivial, and can be overcome by thoroughly saturating the
porous aggregate to prevent suction, but the fact still remains that after this or other excess water
has dried out, the body of the concrete must still be porous, and this is one, if not the principal
reason, why some concretes are not damp-proof The quantity of matrix used for ordinary concrete
being very much less than the quantity of aggregate, and the matrix not being of sufficient
thickness to resist the force of atmospheric moisture, the damp finds a ready passage through the
porous portions. A mass of porous aggregate will ab.sorb external moisture, and this will gradually
work through the body to the weakest or driest surface, or be retained for a time according to the
state of the atmosphere. The extra keying power claimed for a porous aggregate is infinitesimal.
It may be said not only to be of no value, but unnecessary, bearing in mind that in well-made
concrete every particle of aggregate is enveloped with matri.x.

Another point to be considered is the great tenacity of Portland cement to most clean
surfaces, however smooth. Many men will have noticed how it clings and adheres when set to iron,

462 Plastering — Plain and Decorative.

even to the smooth blades of trowels and shovels. The ultimate tenacity of neat Portland cement
after being gauged twelve months is about 500 lbs. per square inch.

Compound Aggregates. — The proper selection and use of aggregates for a true concrete
is not secondar}', but of equal importance to the matrix. As inferior aggregates are in the majority,
it is advi-sable to take their defects into consideration. For concrete floors, roofs, and stairs, where
strength, durability, and fire-resisting properties are imperative, gravel and coke-breeze as aggregates
stand lowest in the scale. Owing to their abundance and cheapness, however, or for want of better
materials, their use is often unavoidable. Their individual defects may be partly if not wholly
corrected by a combination of two or more aggregates .so as to balance their respective good and bad
qualities. It is .self-evident that the hard, non-porous, and incombustible nature of gravel will correct
the soft, porous, and combustible nature of coke-breeze, and that the light, rough, angular, and
elastic nature and variety of size of coke-breeze will counterbalance the disadvantages of the heavy,
smooth, round, and rigid nature and uniformity of size of gravel. The strength, irregularity of size,
and form of broken bricks, and its incombustible nature, causes it to be a direct gain to either of the
above. The mixing of various aggregates may seem of small importance, but if b\- their judicious
amalgamation the strength is enhanced, or the weight or cost of the material decreased, or again, if
the practice enables any waste or by-product to be utili.sed, then the advantage becomes obvious.
To argue by analogy, it is well known that it is by the judicious combination and manipulation
of various materials that mortars and cements attain their strength and harrlness, therefore the same
course will give equally good results with concretes, while rendering economj- with safety possible.

The compressive and tensile strength of concrete is influenced both b}- the matrix and the
aggregate. Aggregates which are uniform in size, (or if of various sizes, which are not graduated
in proportion to each other), or having their surfaces spherical, soft, or dirt}% will not bind with
the matrix, or key or bond with each other, so well as those which are of various graduating
proportional sizes, and have their surfaces hard, angular, and clean.

Sand and Cement. — Sand is extensively used as an aggregate in Portland cement for cast
work, mouldings, and wall ])Iastering. Fine sand does not give so good results for strength as
coarse sand, and a hard-grained sand is more durable than a soft one. Ground brick-bats or
pottery, sandstone and flints, fine gravel, smith)- ashes, and coke-breeze are often used as substitutes
for sand.

It has generally been assumed that sharp coarse Thames sand is one of the best and strongest
for gauging with cement, but, according to e.xperiments made by Mr Grant, clean sharp pit sand
gives better results, as he found that whereas test briquettes having a sectional area of 2% super-
ficial inches, composed of equal proportions of Thames sand, broke at the end of twelve months
with a tensile strain of 724 lbs., it required 815 lbs. to break briquettes composed of equal
])arts of cement and pit sand. \\'ith reference to various sands suitable for making mortar with
cement, Mr Grant's experiment is of a most surprising nature, as it indicates that sand made from
ground clay ballast, or ground brick — which are identical — and Portland stone dust, were superior
to pit or sea sand, or smiths' ashes.

The following table shows the results of tests of various aggregates made by Lieutenant Innes,
R.E. The briquettes were composed of Portland cement, sand, or other aggregates, in the
proportion of i to 2, and were kept in water for seven days.

Sands and Cement.

463

Table IX.— Tests of Various Sands, &c., and Cement.

Nature of Sand, &c.

Voids per
cent.

Shrinkage
per cent.

Grains

above

bSj inch.

Tensile Strength in lbs. per square inch.

Three
Weeks.

Proportional
Value of
Sands.

Dry.
38

43
32
41
46

Wet.

34
36

34
52

Three
Months.

Value of
Sands.

Neat cement

Sea sand, roughish and une%en grain, chiefly
siliceous, clean ------

Sea sand (drifted), siliceous, clean

Pit sand, containing small shells, S:c., grains
of unequal size, siliceous - - - -

Pit sand, grains smooth and uniform, sili-
ceous, clean ------

Portland stone dust, grains rough and irregu-
lar, clean - - - - - -

Smithy ashes, containing much unburnt coal-
dust, grains rough and irregular

6
II

1 1

•5
76
56
56

450

140
60

108
94

165
38

52.4
22.3

40.1

34-9
61.3
14.1

529
249

>93
243
175
254
91

70.1
54.3

69.8
49.8

■'■5
25.6

It will be seen that Portland stone dust gave the best results, and the others follow in this
order — coarse sea sand, rough pit sand, smooth pit sand, drifted sea sand, and lastly smithy ashes.
If the dust had been eliminated, the tests would be more valuable. The degree of coarseness has
a considerable influence on the strength of concrete and mortar. Fine sand makes weaker mortar
than coarse. The following table gives the results of two series of tests carried out by Mr Grant.
The cement was sifted through a sieve with 2,580 meshes to the square inch, and was made into
briquettes with 3 parts of sand by weight. .All the briquettes were kept in water.

Table X.— Tensile Tests of Portla.xd Ce.mext and Sand (Coarse and Fine).

No.

Sand tested
by sieves.

.\t 28 day;;.

60 days.

91 days.

iS2 days.

273 days.

364 da>-s.

First Series —

Nos.

lbs.

I cement to 3 sand

20-30

78.5

1 1 3.9

I 16.9

142.3

I 78

205.5 1

ditto.
Second Series —

10-20

I 37. 1

239-5

223

231.5

254-5

251.5

I cement to 3 sand

20-30

117.2

'34-5

'45

156

157-8

2.3 1

ditto.

10-20

212

236.5

206

253

267.5

273-5 i

In the above each figure is the average of ten tests, the result being given in lbs. per square
inch. The sand used in tests i and 3 pas.sed a sieve with 400 meshes to the square inch, and the
sand u.sed in tests 2 and 4 through a sieve with lOO me.shes to the square inch.

Fireproof Aggregates.— The selection of the best known fire-resisting aggregate for fire-

464 Plasterins[ — P/aiii and Decorative.

proof concrete construction is of vital importance. Granite, stone, and flints splinter and crack
when subjected to great heat, or to the sudden reaction caused by the cold water used for extin-
guishing fires. Coke-breeze is a great conductor of heat, and is also extremely porous and generally
weak. Coke-breeze concrete, when under the influence of intense heat, as for example in the midst
of a building on fire (stated by Captain Shaw to be from 2,000° to 3,000° Fahr.), will gradually
calcine and crack, and finally fall to dust.

Slag is one of the best fireproof aggregates. It is a well-worn axiom that " what
has passed through the fire will stand the fire." There is no other material that has pas.sed the
ordeal of fire like slag. Its great hardness, density, and angularity (when crushed) all tend to
make it one of the best substances for fireproof construction. Slag is cheap and abundant, but
requires great care in selection, as some kinds contain a large amount of sulphur, which is very
detrimental to I'ortland cement, causing the concrete to blow and e.xpand. The jjre.sence of suljjhur
can often be detected by the smell alone. When sulphur is present in a heap that has lain for some
time, or sufficiently long to allow the atmosphere to cleanse the outer surface, it is more difficult to
detect. A hole should then be dug in the hea]), and the |jresence of sulijhur can be ascertained bj-
smell, heat, and colour. It will smell strong, and if new will be warm, and show yellow patches.
The power of the sulphur is so great that washing the slag once will not entirely cleanse it. In
some cases frequent washings and long exposure to the air is necessary. There are some slags
that are free or nearly so from sulphur, and which can be had direct from the iron furnaces. The
slag from the Kettering coal and iron furnaces is largely emplo}'ed for concrete paving. It is
hard and practically free from sulphur. The best size is §-inch screenings. This when sifted yields
a fine kind for topping, and the residue is useful for the rough coat.

The next best fire-resisting aggregates are fire-bricks, pottery, scharff, hard clinkers, and pumice-
stone. The last has the advantage of being extremely light, but it is too soft for frictional wear.
Coke-breeze may to a certain extent be deprived of its combustible nature and rendered more
fire-resisting by washing and passing it through a |-inch sieve, then adding i part flowers of sulphur
and 10 parts fine broken bricks to 20 [jarts of coke-breeze. The larger breeze rejected by the
sieve can be broken small, or used for internal layers of concrete. The bricks should also be
passed through a |-inch sieve. The finer the breeze and brick, the better for receiving and
retaining nails.

VOID.S IN Aggregates. — The quantit)- of voids or interstices depends on the shape and size
of the aggregates. The least quantity of voids will be found in those aggregates which are broken
small, and contain pieces of various sizes. Gravel free from sand contains about 30 per cent, of
voids, and broken stone of uniform size about 50 per cent. Sand is often mixed with gravel, stones,
&c., to lessen the quantity, or fill the voids, so as to ensure the full strength of the concrete, without
adding more cement than the proper ratio. The following method is used to ascertain the voids in
aggregates : — F'ill a bo.x of known capacity with damp, broken aggregate ; start shaking it during
the oijeration ; then fill the box to the brim with water ; the quantitj' of water is the measure of
the voids in the aggregate. Having now briefl\- reviewed the characteristics of the aggregates
most used, the practical conclusions to be drawn are that the)' should be angular in form, hard in
nature, graduated in size, and clean.

Crushing Strength of Concrete. — The crushing strength of concrete depends upon the
ratio of cement, and the nature of the aggregate. Another important factor is compression, done
by beating and ramming. Compression increases the weight of concrete about 4 per cent., and the
strength about 25 per cent. The following table shows the crushing strength of concrete made

I Vat ey for Concrete.

465

with Portland cement and various kinds of aggregates as given by Mr Grant. The tests were
made with 6-inch cubes. One-half were compressed by beating the concrete into the mould with a
mallet ; the other half were not compressed. The whole were kept in the air for a year before

being crushed.

Table XI.
Crushing StrExXgth (in Tons per Square Foot) of Portland Cement Concretes

H.wiNG Various Aggregates.

NaJure of -\ggregate.

Six to One.

Eight to One.

Ten to One.

Compressed.

Not
Compressed.

Compressed, compressed.

Compressed.

Not
Compressed.

Ballast

Portland stone

Granite

Pottery

Slag ... -

Flints - - - -

81.6
162.4
122
II5.2

92
82

72.8
120
98
98.4
80
62

54
132
78.4
88
78
70

50
98
58
72
56
56

88
62
74

42.
60

32
76
46
56

34
51.2

The granite and slag might have been expected to have given the better results. It is i^robable
that they were unwashed, and contained a considerable amount of dust. If the compression was
done by hydraulic power, so as to obtain a uniform compression in all the cubes, the results would
be more reliable.

W.\TER for Concrete. — Water for concrete should be perfectly clean, and free from organic
and inorganic impurities. As regards the quantity, it can only be said that for such purposes as the
foundations for paving, casting blocks, &c., or where the material can be well rammed, so as to ensure
perfect consolidation, less is required than where the concrete can only be poured or laid in position.
When mi.\ed with insufficient water, the concrete occupies about one-eighth more space than when
mi.xcd with the full quantity, and percolation through the former gauge would be greater than
through the latter. Yet by thorough ramming the former would occup\- less space and offer greater
resistance to moisture. An over-watered gauge is slow to set, difficult to work, liable to surface
cracks, and often there is a loss of strength, caused by escape of a portion of liquid cement. The
work will also be unequal in strength, owing to the liquid cement flowing to various or lower parts,
leaving parts of the aggregate bare and weak.

It must not be inferred from the foregoing remarks that water is entirelj- unnecessarj- or of
little value for concrete. On the contrary, it is of the utmost value. The evil is in the abuse, not in
the use. Portland cement has a great affinity for moisture. For instance, if a sack of cement is left
on or in a damp place, a part of the contents soon becomes set and extremely hard, which is
a proof of its affinity, and that moisture alone will set cement without water, far le.ss excess
of water. Fresh cement requires more water than stale cement. Cement gauged with sea water
sets more slowly than with fresh water. Sea water should not be used in concrete intended for
paving stables, chemical tanks, or similar places where it will come in contact with ammonia.
Sea water having a lower freezing-point than fresh water, is sometimes used in frostj- weather to

466 Plastcyiug — Plain and Decorative.

allow the work to be carried on. It ought not, however, to be used for external work, especially for
plastering facades, as it has the property of attracting moisture and causing an efflorescence on the
surface. Sometimes in frosty weather hot water, also hot lime, is used for concrete ; but although
they hasten the setting, they often prove fatal to the strength of the concrete. Excess of water
retards the setting and hardening of concrete ; it also washes away some of the finest and best
particles of the cement during the gauging. A part of the water also forms in little globules
throughout the mass, and when the water-drops evaporate a series of small holes or blubs is left,
which deteriorates the strength of the concrete. Finally, it ma)' be stated that the quantity of water
required for gauging concrete is regulated by the class and condition of the aggregate, by the state
of the atmosphere, and by the purpose for which the concrete is required. Another important ])oint
is the careful and thorough incorporation of all the materials when gauging. A mass of raw
materials, if gauged carelessly, will require more water to attain the same plasticity as that which is
carefully gauged. Approximate quantities of water are given for Portland cement plastering. For
concrete the quantitj' is about 21 gallons of water to i cubic yard of dr)' materials, or about i part
b}' volume to 8 parts. It is a good maxim to bear in mind when mixing water for gauging concrete,
that other things being equal, the minimum is better than the ma.ximum. Water may be said to
give birth to the strength of cement ; to carr}- the simile further, the aggregate may be termed the
bone, the matrix the skin and sinew, and the water the blood of concrete.

G.VUGING Concrete. — It is a common idea that concrete can be gauged and used anyhow,
with an)- aggregate, or with an)- amount of water ; and in consequence of a laxit)' in supervision in
the selection of the materials, and their correct gauging and manipulation, unsatisfactory results are
sometimes arrived at, the blame being attributed to the wrong cause. Gauging concrete requires
considerable care to avoid waste of materials and obtain the best possible work. Concrete can be
gauged either b)- hand or by machinery. For small quantities, such as for stairs and similar work,
the former is almost in\ariabl)- used ; and for large quantities, such as for foundations of buildings,
&c., the latter, being more economical, is preferable. Mr R. E. Ta)-lor, C.E., of Newcastle, has
invented a mi.xing machine which can manipulate i cubic yard at a time by hand. A careful and
uniform method should be employed for hand gauging ; nothing should be left to chance or rule of
thumb. The gauge-board .should be sufficiently large to allow the materials to be turned over
without spilling, it should be placed as near the work as possible, and it should be cleaned after
each gauge.

For fine concrete, no more than i cubic yard should be gauged at a time. This is as much as
three men can properly gauge at once and in the proper time — that is-, before the " initial .set " begins.
Portland cement concrete, unlike some mortars, does not improve b)' prolonged working. If larger
quantities are desirable, then more men must be employed in the gauging. All materials should be
measured for each gauge, to ensure uniform setting and strength, and also the best work. This,
combined with the saving of time and materials, will repay a hundredfold the cost of the measures.
It is a common )-et a wrong wa)-, when gauging for paving purposes, to measure the aggregate by
so man)- barrowfuls to a sack of cement. Neither the aggregate nor the cement can be accuratel)'
measured in this haphazard wa)-. No man fills a barrow twice alike, and the cement being
turned out of the sacks direct on to the aggregate is apt to var)-, as it may contain lum])s caused by
damp, and very often some of the finest of the cement is retained in the sack, as more often than
not it is simpl)- drawn up and then thrown on one side without shaking it, as would be, or at least
should be, done if the cement was emptied for air-slaking. The aggregate should be measured in a
bottomless box or frame with handles at the ends, the cement in a box (with a bottom), and the

Concrete Paving. 467

water in a gallon metal measure or a pail made to contain 4 gallons, ^'ive pailfuJs of this size are about
sufficient to gauge i cubic yard where the concrete can be well rammed or punned. For work that
is simply laid, i gallon extra is required. The box frame is laid on the gauge-board and filled with
aggregate (in a damp state). The frame is lifted off, and the aggregate spread over the board until
about 6 or 7 inches thick. The cement is then distributed over the aggregate. The materials are
then gauged bj- three men, two with shovels and one with a rake or larry, the former facing the
latter. The dry materials should be carefully but energetically turned over twice, and then when
being turned over the third time water must be gradually added by means of a rose fixed on a
water-can. Water poured from a pail is apt to wash parts of the cement away ; the water also
cannot be so regularly and gradually distributed over the dry materials as when a rose is used. The
mass is again turned over twice or even thrice until thoroughly incorporated. This turning over
does not consist of merely turning the mass o\-er in the centre or on one place of the board, but to
be effectively done a shoveller should stand at each side of the board, and the raker at the end to
which the mass is to be first turned ; the shovellers lift the stuff and spread or rather scatter it on
one end of the board with a jerking motion, and the raker further mixes the stuff by working each
shovelful backwards and forwards. This is repeated, the stuff being turned to the other end of the
board, after which it is turned to the centre, the water being added as already described. The wet
mass is then turned over twice in a similar manner, and finally finished in the centre of the board.
The shovellers in the final mi.King turn the stuff from the outside of the heap to the centre, while
the raker gives the final touches. After being gauged, it should not be disturbed, but immediately
shovelled into pails, and conveyed to the place of its use. The " initial set " begins nearly or as soon
as gauged, and any after or unnecessary disturbance tends to destroy the setting properties of the
cement. The practice of gauging, and afterwards regauging or knocking it up, is most objectionable,
as it destroys its setting properties. No more should be gauged at one time than can be conveniently
laid in one operation. The gauging of this valuable materia! should not be left entirely to unskilled
labour, but ought to be carried out under careful supervision.

Ramming Concrete. — The ramming, beating, or punning of concrete is of great importance.
It compresses the concrete, rendering it more dense and free from voids, and forces out all superfluous
water. The resultant gain in strength, durability, and imperviousness is by no means to be
despised. Without compression it is impossible to obtain impervious concrete. Prolonged
ramming, however, is dangerous, as it may be continued until the cement is set, which would be a
direct loss of strength. For this reason, the ramming of concrete made with quick-.setting cement
should immediately follow the deposition of the material, and be expeditiously done. The concrete
should always be gauged rather stiff than soft. If in the latter form, the ramming will separate the
more fluid portions, and produce strata of different densities. When the concrete is deposited in
layers, the joints of each layer, if dry or exposed, should be well swept and watered before the next
layer is deposited. It is often advisable, especially in very dry work, to brush the joints with liquid
cement after they have been swept and wetted. For large constructional work, the joints should
also be keyed by aid of a pick, or by inserting stones at intervals into the concrete before it is set,
leaving them projecting 3 or 4 inches above the level of the joint. Another method of forming a
key is effected by forcing a batten on edge about 2 or 3 inches deep into the concrete, at the
middle of the joint, and when the concrete is firm or nearly set the batten is extracted, thus leaving
a groove which forms a key for the succeeding layer.

No layer that has to be left for some time, or until dry, should be less than 4 inches deep.
Thin layers are always a source of weakness. If the successive layers can be laid before the

468 Plastering — Plain and Decorative.

])revious one is firm or set, the thickness is not of so much consequence. For large work, when each
la)-cr has to stand until set, the thickness may vary from 9 to 12 or even 18 inches. Ramming may
be done by using an iron punner, or one made of hardwood and bound with iron. Wooden mallets
and punches or iron hand-floats are most suitable for ramming stairs and cast work. The gain in
strength is shown in Table XI. of the crushing strength of Portland cement concrete.

Thickness ok Concrete P.wing. — The thickness of concrete paving laid in situ is regulated
according to the purpose and the position of the work. The thickness also depends upon the nature
and solidity of the foundations. It is obvious that a thicker paving is required for a foundation
that is weak or soft than for one that is strong and hard. The best foundations are those composed
of strong and well-laid rough concrete. Foundations composed of broken bricks or stone thoroughly
consolidated b)- ramming are the next best. The thickness of foundations is also regulated by the
nature of the soil and the subsequent traffic. Paving for the side-walks of main streets, or where
the traffic is heavy and continuous, should not be less than 2 inches. For a medium traffic, and on
a strong foundation, a thickness of \\ inches will be sufficient. For side streets, garden paths,
passages in houses, or similar places where the traffic is light and limited, a thickness from i to li
inches will be ample if on a rough concrete foundation ; but if on a " dry," i.e., broken brick or stone
one, the thickness should not be less than li inches. The thickness for stable floors may vary from
3 to 4 inches, according to the class of horses. For instance, a thickness of 3 inches would be ample
for race or carriage horses, but 4 inches is necessary for heavy cart horses. The same rule applies
to yards, a thickness of 3 or 3?, inches being sufficient for carriages, while 4 inches is required for
carts, waggons, &c. Factor)' floors are generally made 2 inches thick, but where there is machinery
or wheel traffic a thickness from 2i to 3 inches is employed. By computing the volume and nature
of the traffic, and comparing the tests of concrete paving herein given, the requisite thickness
will be readily obtained. It must of necessity greatly depend on the class of the materials and
manipulation used for the paving. Like most other articles, a good material will go further and
last longer than a bad one.

Concrete Paving. — Good pavements proclaim a city's progress. Isidorus states that the
Carthaginians were the first people to pave streets. The subject of paving and floors will be best
understood by dividing it into two parts — namely, paving, which is a floor surface laid and resting
on solid ground ; and floors, by which are meant floors over voids. The following items briefly
embody the processes used for most concrete pavings now in use. The method of laying is
detailed in Eureka concrete. Paving i)i situ is either laid in " one coat " or " two coats," the latter
being in more general use than the former, yet each method has its individual merits. One-coat
work is not so liable to rise or laminate as two-coat work. It takes slightly less labour, the whole
thickness being laid in one operation. The aggregate is either granite or slag, or both in equal
proportions, gauged with Portland cement in the proportion of 2 of the latter to 5 of the
former. Two-coat is laid with two different aggregates and gauges. The first coat has a cheap
aggregate, such as ballast, clinkers, bricks, or whinstone, broken so that they will pass through a
I -inch mesh riddle, and gauged in the ratio of r of Portland cement to 5 of the aggregate. It is
laid till within i inch of the finished surface. The second coat is laid as soon as the first is set, and
is composed of i part of Portland to 2 of aggregate, the latter being either crushed granite, slag,
limestone, or whinstone that will pass through a j^Vinch sieve. In some districts fine shingle is
used for the topping aggregate.

Patent Metallic Pavinc,.— This is one of my patents, which, under the title of Wilkes'
Metallic Flooring and Eureka Concrete Company, was extensively used in Great Britain and Ireland

Eureka Paving. 469

and the Continent. The Austrian and Belgian patents were worked in both countries. This pa\ in^^
was awarded a gold medal at the Health Exhibition, 1884; a gold medal at the Architectural and
Building Exhibition, 1886; and the only gold medal at the Firemen's Exhibition, 1886, as well as
five diplomas of merit. The materials and method are nearly the same as that described for
Eureka ; but in order to avoid waiting for a considerable time (which it is usual to do in concrete
work, before it can be used for traffic), I invented a quick-setting solution, termed " Reekie," to
accelerate the setting. For this rajjid concrete 5 per cent, of Reekie is added to the concrete
materials. The following extracts refer to the paving, and to the Reekie or quick-setting .solution.
The Engineer, 1885, after referring to the various works done with this matter, says : " A feature
of the invention is the rapidity with which the composition sets. F"or instance, a roadway was
finished at the Inventions Exhibition at seven o'clock one night, and at six o'clock the next morning
4 or 5 tons of paper in vans pas.sed over it into the building, without doing any harm to the
new road." In laying down roads, much of the preparation of the material is done on the spot, and
the composition after being put down unsilicated in a large layer, has the required design stamped
upon its wet surface by means of wooden or gutta-percha mould.s. Sometimes the grooving is
made in imitation of ordinary granite paving setts. In tramway pavements there are grooves to
give a grip to the horses' feet, and a slight camber between the rails. The great advantage in laying
a pavement by this method is, that when any repairs are necessary, a piece of the exact size can be
manufactured at the works and stamped to the same pattern as the adjoining pavement, then placed
at once in position on the removal of the worn portion, thus saving the time necessary for setting on
the spot. The following is taken from a series of articles on artificial stones, which api^eared in TIu
Builder in 1888 : — " For Wilkes and Millar's patent paving stone, which is stated to be hard, durable,
and non-slippery, a mixture is employed of finely powdered and washed blast-furnace slag, 3 parts
to I part of h}'draulic cement, to which is added sufficient water, containing in ever\- gallon i part
of bittern water, 5 per cent, of carbonate of soda, 2i per cent, of carbonate of ammonia, and a little
potash. If I ounce of sulphate of lime is added to this solution the stone will set more quickly."

Quick-setting solutions are used to reduce the time required to allow the paving to harden
before it is available for traffic. Many pavements are ruined by being used before having become
sufficiently set and hard. Many of the so-called quick-setting materials have the desired effect of
setting the concrete quickly, but the work m many cases is subject to subsequent blowing, expanding,
and cracking. On no account should these quick-setting materials be used, unless thoroughh- tested
and the concrete proved durable by use and time. In order to protect the surface and allow the
paving to be used immediately, P. M. Bruner, an American engineer and concrete specialist, covers
the surface of the pavement directly it is finished with a thin coat of plaster or Parian cement,
which admits of walking upon in a few hours, and resists pedestrian traffic until the surface proper
is sufficiently hard, after which it is shelled off with a trowel.

Eureka Paving. — I have retained the term Eureka for an improved concrete, which has
been extensively used with good results for many purposes, such as pavements, floors, and stairs.
Eureka, if not exactl\' one-coat work, is nearer that than two-coat work, and ma\- be said to be the
happy medium, or a combination of both. Eureka is laid in two la\-ers. The first is termed the
" rough coat," and the .second the " fine coat " or " topping." The topping is laid nearl\- as .soon as
the rough coat is laid, just as in rendering or dubbing-out plaster work. The materials and gauges
are nearly alike for both layers. The gauged rough stuff is laid on the foundation, previously
wetted to prevent suction, and spread and beaten with an iron hand-float. The laying, spreading,
and beating are continued until the rough surface is within A inch of the finished line. The surface

470 Plastering — Plain and Decorative.

of the rough coat is made fair, and a uniform thickness for the topping is obtained by passing a
" gauge-rule " across the surface. A uniform thickness of topping gives an equal expansion,
therefore the surface is not liable to crack. The suction is also more regular, which permits of the
trowelling to be done with greater freedom, and without causing hard and soft places on the
surface.

As many alternate baj's are laid as will allow of all being topped and finished the same day.
When the number of bays to be laid in on one day has been decided, and the last one roughened
in, the first bay will be firm to receive the topping. The topping is laid and spread with a wooden
hand-float, ruled and trowelled and brushed as afterwards described in the general process. This
method of laying a part of the thickness of the paving, gauging stiff and beating the mass, forces it
into the interstices of the broken dry foundation, and not only consolidates the foundation and the
rough coat, but also forms a solid bed to receive the topping. The topping goes in sooner and
more regularly on a stiff-gauged and well-beaten coat than on a soft-gauged one, or than if the
whole thickness of the paving were laid in one coat.

EUREK.\ Aggregate. — The method of preparing the aggregate for Eureka is of the utmost
importance. The labour expended on its preparation is more than repaid, not onh' in the ease and
rapidity when finishing, but also in the satisfaction of doing a strong and workmanlike job. Slag
or granite is far more preferable to gravel or stone as an aggregate. Slag and granite in equal
proportions have been used with good result.s. The size ordered from the furnace or quarry should
be |-inch screenings. It must be washed through a ^-inch sieve in a tub or iron tank. The coarse
part rejected by the sieve to be laid aside for the rough coat. The fine aggregate is then washed
again through a fine sieve to extract any mud or impalpable powder, as the presence of such
impurities weakens the consolidating power of the cement, and decreases the ultimate strength of
the concrete. This fine aggregate for the topping should be angular and of various graduating
sizes, from that of fine sharp sand to the largest size that has passed through the |-inch sieve. It
has been proved by e.xperiencc and the test of time that an artificial stone made with a fine
aggregate has not only more resemblance to the grain or te.xture of natural stone, but is also denser,
and wears better and with more uniformit)-, than one made with a large, round, or equal-sized
aggregate. The u.se of small and angular aggregate of the graduating sizes ensures their fitting
closer and interlocking together, thus forming a stronger bond, giving a regular key and freedom
for each separate piece to be coated with cement, the whole forming a solid and homogeneous
body with a hard surface. Concrete with large or round aggregate, and the various pieces
disproportionate in size to each other, will fit loosely and unevenly, and only touch at their most
prominent points, thus leaving voids, and consequently unsound work. The voids may perchance
be wholly or partly filled with matrix, still this is an unnecessary waste of cement. Consequently,
concrete paving having large or round aggregate wears uneven!}-, and leaves the large or round pieces
uncoated and loose, or so e.xposed above the surface that they soon get dislodged, leaving a series
of small holes, which sooner or later wear larger and larger. Another point of importance is that
concrete with a fine hard aggregate is more plastic, works freer, and has a greater compressive
strength than concrete with a large or soft aggregate. Eureka concrete, having a fine, clean, and
regulated aggregate, should be used for the topping of paving, steps, landings, or for any class of
work e.xposed to friction or wear. It is well to remember that a good matri.x will not make a bad
aggregate strong, although a bad aggregate will make a good matrix weak, or rather the resultant
concrete weak.

EUREK.\ Qu.VXTITIES. — The quantities for the rough coat are i part of Portland cement and

Levels, Falls, and Foundations. 471

4 parts of the coarse portion of Eureka aggregate. These materials must be gauged stiff, onlj- as
much water being used as will allow the mass to be thoroughly mixed and plastic. The quantities
for the topping are 2 parts of Portland cement to 5 of fine aggregate, and gauged about the
consistency of well-tempered " coarse stuff," as used for floating. Experiments prove that neat
cement is inferior in wear-resisting qualities (such as frictional wear and pedestrian traffic; to mix-
tures of cement with sand or other aggregate, being in fact equal to a mixture of about i part of
cement to 3 of aggregate. The best wearing qualities are obtained by a mixture of 2 parts of
cement to 3 of aggregate.

Level.s .\ND Falls. — Accurate levelling and adjustment of the requisite falls are important
features for pavements and flooring. Levelling is the art b\- which the relative heights of any
number of points are determined. Falls are used to allow rain and water used for cleansing pur-
poses to run off into channels and drains. The levels and falls in good buildings are generally
marked on the drawings, but it is imperative that the worker should be conversant with the necessary
amount of falls for paving purposes, as many unforeseen difficulties often arise in this class of work,
especially in large surfaces. The most accurate and speedj- wa>' of setting out levels and falls is of
special service to concrete paviors. The importance of these features will be readily appreciated,
especially where these paving preliminaries are left to the care of the concrete layers. The amount
of cross fall for street pavements varies according to the class and position of the work. The fall is
also regulated by the gradient. For a level stretch of paving it is generally I in 60, therefore for a
pavement 6 feet wide it would be i inch. The fall for rising ground is usually \ inch for every 2 feet
in the width of the pavement. The falls for stables and yards are given under their respective
headings. The points for levelling — also for falls — are formed by driving wooden pegs into the
ground at the most suitable points. The heads of the pegs represent the finished face of the pavement.
They are made level with each other by the aid of a parallel rule and a spirit-level. Intermediate
pegs may also be levelled b}' means of boning rods, the use of which is explained in the Appendix.

Pavement Foundations. — Good foundations for concrete paving are of primary importance,
and unless the bottom is firm, and the foundation sound, the best made and laid concrete will
subside, crack, and be permanently spoilt. Pavements generally cover a large area, and the super-
structure, however strong, must have a firm foundation. Foundations consists of two parts — the
first is the bottom ground or natural foundation ; the second is the made-up or artificial founda-
tion ; but for simplicit}- the first part is termed the " bottom," and the latter the " foundation." The
latter may be " dry " or " gauged." If the bottom is soft, it must be well rammed before laying
the dry materials for the foundation, or a laj-er of common coarse concrete for gauged work.
When excavating the ground to receive the foundation, the depth from the intended finished
surface of the pavement should be about 5 inches for paving 2 inches thick, 6 inches deep for
paving 2i inches thick, and 7 inches deep for paving 3 inches thick. The above depths are for dr>-
foundations, and where the traffic is light, such as side-walks, playgrounds, and passages. If the
bottom is soft, or the paving intended for heavy traffic, the depths may be increased, and the
bottom well rammed before the materials are laid. The materials for dry foundations are broken
bricks, stone rubble, or other hard core. They should be spread on the bottom, and broken in situ.
The breaking in situ tends to consolidate the bottom and foundation. When broken, no piece
should be left that will not pass through a 2i-inch ring. If the paving is intended for heavy
traffic (carts or the rolling of heavy casks), it is best to have a rough concrete foundation. The
rough concrete should be from 4 to 7 inches deep, according to the firmness of the bottom and
class of traffic. This concrete is composed of ballast or equal parts ballast and broken bricks.

47^ Plastering — Plain and Decorative.

coke-breeze, or hard clinkers, gauged in the proportion of i of Portland cement to 5 or 6 of
aggregate. It should be laid to the desired fall. If lime instead of Portland cement is used for
the rough concrete, great care should be taken to thoroughly damp the surface, and allow a sufficient
time for the lime to expand and any lumps of unslaked lime to slake, before the fine concrete is
laid. No paving should be laid until the rough concrete is thoroughly set. Allowance must also
be made for any settlement of the bottom, and for any subsidence, contraction, or expansion of the
concrete foundation. The rough is not so liable to contraction or expansion as fine concrete, but
it is more liable to subsidence. Expansion is flue to the cement, not to the aggregate ; and as
there is less cement in rough concrete than in fine, it has less power of expansion, and owing to
the greater amount and weight of aggregate, there is the lesser power of contraction. The size of
aggregate for rough concrete is also larger than for fine ; consequently each piece offers a greater
resistance to the cement. Subsidence is due to the settlement by gravitation of the aggregate to
the bottom, which takes place after the e.vcess water, or even the liquid cement, has percolated
through voids or spaces of badly made or laid concrete. Unequal subsidence is caused by bad
and unequal gauging; one gauge being firm keeps in position; while if soft and sloppy, the
excess water cither settles in the deepest places, or escapes into the ground, thus allowing the body
of the concrete at those parts to subside.

Screeds and SectioN.S. — Screeds are used as guides and bearings for levelling and ruling
off. They are generally formed with wood rules, planed on all sides, and in suitable sizes, and
are termed "screed rules." Screeds arc sometimes formed with the same kind of material as
used for the pavement, and are termed " gauged screeds." Screed rules give the best results ;
they are speedily laid, can be used at once, and form a clean and square joint when laying work in
.sections. Screed rules are temporarilj' fixed on the foundations b\- la\ing them on narrow strips of
gauged concrete, aiul then made straight, and to the pro|3er falls, b_\- la\-ing the edge of a straight-
edge on them, and tapping with a hammer till firm and true. When the bay is finished and set.
the screeds are removed by gentl)' tapping with a hammer, leaving a clean, straight, and square
joint. Where there is onl\- a small quantit\- of screeds required, or where time will not permit of wait-
ing for the concrete bedding strips to set, the screed rules can be fixed on gauged plaster, which allows
the .screeds to be used at once. The plaster should be cleaned off at the side intended to be laid,
to ensure a sound bed for the concrete, and a square joint. Gauged screeds may be also formed
with gauged coarse plaster. They are best done as described for " pressed screeds" (Chapter VI.).
In la\-ing large surfaces it is best to arrange the screeds, so that the work can be laid in alternate
.sections or bays, which will afford greater facility to get at the work, and also to allow the isolated
bays to expand. For instance, if laying a stretch of street paving 50 feet long and 6 feet wide,
this would be laid out in ten 5-feet bays, the screed rules, each 6 feet long, being laid so as to
form the odd numbered bays to be laid and finished first. This allows the workmen more freedom
b)- standing on the empty bays when finishing the laid ba\-. The screeds arc then removed, and
the intermediate bays laid, the sides of the finished bajs serving as screed or bearing when ruling
in. Boards or bags are laid on the finished bays to protect the surface, and give a footing for a
workman to finish off the intermediate spaces. It must not be forgotten to fix the screed rules
with the necessary fall towards the kerb, also to keep the ends of the screed about f inch above
the kerb, to allow for any subsidence, and for water to run off. This al.so provides for the greater
amount of wear that takes place near to than actually on the kerb. The foundations should
be thoroughly saturated with water before the screeds are fixed. If this is not done, the brick
or other dry material used will absorb the moisture or life from the concrete, and render it

Laying Concrete Pavements.

473

dry or dead. The drenching with water also frees the broken materials from the dust caused b>-
breaking the large pieces in situ. In laying paving on a gauged foundation, the surface should be
well swept with a hard broom and afterwards damped, so as to ensure the perfect cohesion and
solidity of the foundation and the paving. The kerbs and channels are sometimes made in situ,
but more often thej' are cast and laid in the same manner as ordinary stone. Cast work is harder
than laid work; it also allows the paving to be laid with greater freedom. Illustration No. i88
shows sections of street kerbing and channel which may be used in connection with slab paving, or
pavements laid in situ.

Laving Concrete Pavements.— The foundations having been damped, and the rough stuff
gauged, it is carried in pails and emptied at the top end of the bav-. The plasterer spreads it with a
laying float, and rams it well into the foundation. When he has laid a stretch the whole width of the
bay, and as far as he can conveniently reach, he moves back and lays the remaining portions of the
bay in the same waj' until complete. The rough stuff surface is then made fair, but not smooth, with
the gauge rule. The remainder of the bays are dealt with in rotation. The fine aggregate is then
gauged, and laid and spread until flush with the screeds. The stuff .should be rather above than
below the screeds, to allow for subsidence by subsequent ramming, ruling, and patting. All
concrete bodies over 2 inches thick should be deposited in layers. Each laj-er should be well
rammed with an iron punner, or a hardwood punner
bound with iron. Concrete gains strength b\-
compression, and consequently its density, im-
perviousness, and durability is increased. Even for
2-inch pavements better results are obtained if
the stuff is deposited in two laj-ers, each layer well
beaten with an iron hand-float. If only li inches
thick, it should be consolidated b\- being beaten
with an iron float. The surface is ne.xt ruled with
a floating rule. The rule is worked square on edge,
and the concrete cut and beaten in successive

short and quick strokes. If the stuff is soft and laid too full, the rule is worked loo.sely on edge
with a zigzag motion, so as to draw the excess stuff and water off the surface, and leave the body
full and regular. If there are an}- hollow places, they are filled up with stuff, and the rule again
applied. In all cases the surface should be finally straightened by beating with the rule. This
process leaves the surface more uniform, straight, and solid than by dragging or working the rule.

Trowelling Concrete. — After being ruled, and when slightly firm, the surface is beaten with
a wood hand-float, which lays any irregular parts or projecting pieces of aggregate. The beating or
patting is continued until the "fat" appears on the surface. It is then trowelled, or rather ironed,
the trowel being worked on the flat of the blade with a circular motion. The plasterer, when
trowelling off, should have a hand-float in the other hand to lean on when reaching to a far-ofl" part.
The float is also useful to pat an>- dry parts. The surface must be finished with a semi-dr\- stock-
brush to obtain a uniform grain. A vast amount of care is required in trowelling off". Perfection
can only be attained by practice, and a close observation of the materials, conditions, and the
state of the atmosphere during the progress of the work. The best effects can only be attained by
acquiring a knack of working the trowel on the flat, and b\- knowing when to begin and when to
leave off It is a waste of time, and the cause of an unequal surface, if the trowelling is begun
before the stuff is firm ; but time and labour will also be lost if the trowelling is left until the stuff"

No.

iSS. — Sections of Concrete Kerb, Ch.\nxel, and

P.WING.

474 Plastering — Plain and Decorative.

is too stiff, or has nearly set, for then the surface will be rough and patchy. In either instance the
surface is more or less spoilt, and the ultimate appearance and hardness seriously affected.

Grouting. — The use of neat cement for trowelling off should nut be resorted to (this is
termed "grouting"), and is used when the surface is left till set, or when it has not been properly
patted and trowelled. The expansion of a strong and weak gauge being unequal, the result is that
the surface peels, or should it adhere, it is patchy and discoloured. Where grouting is unavoidable,
the cement should be gauged with an equal part of fine aggregate, the aggregate being the same as
used for the topping.

Dusting. — Another bad process is that of sprinkling dry neat cement over a soft surface
(this is termed "dusting"), and is used to absorb the moisture caused by sloppy gauging. It
has drawbacks similar to grouting. If unavoidable, the cement should be mixed with fine dry
aggregate in the same proportion as the topping. If the stuff were trowelled at the correct time,
there would be no necessity for grouting ; and if properly gauged, no need for dusting. No
concrete surface can be made so solid and hard as when it is finished in one body and at one
time.

Temper.vtuRE. — It is well known that extreme heat and cold affect the expansion and
contraction of iron. The.se extremes have a similar effect on concrete, especially during the
process of .setting and hardening. Equality of temperature during setting is desirable. Cold and
humid atmosphere retards setting ; hot humidity accelerates it. Concrete laid in cold weather
stands better than that laid during heat. Concrete laid in mild damp weather is better than
in either extremes'. During high temperatures, the surface, when sufficiently hard, should be
covered with damp deal sawdust, old sacks, mats, or sailcloth, and saturated at intervals with
water. If the sun's rays are hot, the surface of the work while in progress should be protected
by extending tarpaulin or old sail-cloths above the parts being laid. Concrete surfaces are further
hardened by flooding with water, or where this is not practical, covering with wet sawdust or sand
as soon as set. Care must be taken that the sawdust is clean and of a light colour, as otherwise
it will stain the work.

Non-Slippery Pavement.s. — Concrete pavements for special purposes are rendered non-
slippery by mixing i-inch lead cubes with the topping stuff. Lead cubes about i inch square,
laid by hand from I inch to 4 inches apart in the moist concrete surface, have been used for
rendering concrete surfaces non-slippery. Iron and brass filings are also used for the same ])urpose,
and also for increasing the wear-resisting power of concrete surfaces. Roughened, indented,
grooved, and matted surfaces are also used to obtain a better foothold on concrete surfaces.

Grooved and Roughened Surfaces. — Stables, yards, &c., are grooved and channelled on
the surfaces to prevent animals from slipping, and also to carry off urine or other liquids to the
traps or gulleys. Indented surfaces are useful on steep gradients to give a better foothold.
Grooves are made with a special wood or iron tool, which is beaten into the surface as soon as
the concrete is floated. The grooves, for stables, are generally made about 5 inches from centre to
centre, and the depth about | inch. A line is first made at one end of the work, and the groover \9
then laid on this line, and beaten down with a hammer to the desired depth. Before it is taken off,
a parallel rule is laid on the surface and against the groover, which is then taken up and laid close to
the other side of the parallel rule, and beaten in as before, and so on until the whole surface is done.
The width of the parallel rule is equal to the desired width between the grooves, less the width
of the groover. Grooves, however long, can be made by moving the tool along, and against a long
parallel rule. After a stretch of grooves have been sunk, the surface is trowelled, and the inden-

Grooved and Stamped Concrete Paving.

475

tations made true. It may be necessary to apply the groover again, and beat or work it forward
and backward to further regulate their depth and straightness. They are then made smooth with a
gauging trowel and finished with a damp brush, the sides of the grooves being left smooth to give a
free passage for liquids.

Grooves on a surface having a fall should radiate toward the deepest point. A level surface
may be made to carry off water by the indentations being formed wider and deeper towards the
outlet. Street and other pavements are sometimes indented with metal rollers to give a better
foothold. Platforms and other surfaces are sometimes made rough or indented by beating the
moist concrete with a " stamping-float." This tool is about the same size and shape as an ordinary
hand-float. The sole has a series of squares projecting about f inch, each square about i inch,
and i inch apart. Concrete surfaces are also roughened or matted by dabbing the surface as soon
as trowelled with a coarse stiff whalebone brush. Illustration No. 189 shows three designs of
grooved surfaces for carriage drives, conservatories, &c. Figs, i and 3 were introduced by Mr
Philip Hobbs, the managing director for W. B. Wilkinson & Co. Fig. 2 is known as the herring-
bone pattern. A plain border, or

one with a single width of the ^'S- '■ F'g- 2- Fig. 3.

main design, is generally formed
on the sides and ends of the floor.
A rough matted surface may al.so
be obtained by pressing or beating
a wet coarse sack or matting over
the moist concrete.

St.\mped Concrete. —
Various materials and methods
are used for stamping or indent-
ing concrete surfaces to obtain a
better foothold, or to form any
desired pattern. Iron stamps are
generally used, but owing to their
weight and rigid nature, are
unsuitable for large sections.

Plaster stamps are sometimes used for temporary purposes, or for small sections and quantities.
Stamps for large concrete surfaces should be composed of a material that is easily made to the
desired form, durable, and slightl}- flexible. For this purjjose I used wood, also gutta-percha, for
stamping the concrete paving in the streets of Old London at the Health Exhibition, 1884. The
side walks were imitation red bricks, with a herring-bone design. The design was indented with
a wood stamp 3 feet long and 2 feet wide. The ground of the stamp was formed with i-inch pine
boards, held together with ledges on the back, the design being formed on the other side with
projecting hardwood fillets to form the brick joints. The pavement topping was composed of
fine Eureka concrete, coloured red, and laid I inch thick on a rough concrete foundation. After
the surface was lightly trowelled, the stamp was laid on and pressed down by means of a man's
weight. The stamp was then taken off, and laid to intersect with the previous joint, the process
being repeated until the whole surface was indented. For the roadway, natural coloured concrete was
used, stamped in imitation of the old-fashioned cobble stones. A plaster model about 4 feet square
was made, the stones being kept very irregular in size and form. From this model a gutta-percha

tfTttJ-.

No.

189. — Three Exa.mples of Grooved Surfaces.

476 Plastering — Plain and Decorative.

mould was taken, and tlic impression on the soft concrete obtained by stamping as before. T.
Galloway was foreman on this work. The Portland cement was supplied by Messrs Hilton,
Anderson, & Brooks. A most unusual method was em|jioyed for forming a rough surface on the
crranite concrete platforms at York Railway Station. The work was done by IMessrs Wilkinson &
Co. in 1890. It was laid in bays about 12 feet square. The topping was laid full, but the surface
was neither beaten with a float, nor even trowelled, but simply ruled fair by gently tapping with a
straight-edge, so as to leave a series of small ridges about i| inch deep, | inch wide, and about \
inch apart. As there was no compression or consolidation by beating or trowelling the surface, the
ed^es of the ridges (if not the whole surface) must soon wear, and become ragged. It is probable
that the contractors were working to a specification, as from their long practical knowledge of
concrete paving, they would not be likely to adojit this method of their own accord.

Expansion Joints. — Compressive or flexible joints are u.sed to allow for any expansion or
contraction that may take place in a large area of concrete paving exposed to atmospheric
changes. There are various methods in use for the purpose. The first is to .set out the area in
small sections, and to lay them in alternate or isolated bays, thus giving time for their expansion
before the intermediate bays are laid. This method, by dividing the area into small sections, is
the best for preventing cracks, because small sections are stronger than large ones ; and in the
event of any subsidence in the foundation, the surface fissures are limited to the immediate joints of
the sections. Contraction and expansion are also less in small bodies than in larger ones. A good
example of this method can be seen on the platforms of the railway station at Rugby, e.xecuted by the
Imperial Stone Company. There are about 8,000 yards superficial, laid out in sections, each about
I yard square. The work is 2 inches thick, and laid on a bed of sand. The latter rests on a rough
concrete foundation. The sides of the first laid sections were oiled before the next was laid, so
as to allow of any section (with the aid of the sand bed) to be taken up, if required, for repairing
gas or water pipes, &c. Compressive joints are formed by laying strips of wood, paper, felt, lead,
or rubber along the sides of the first laid bays. The strips are made the same width as the
thickness of the paving, and are laid flush with the edges of the paving. Wood strips about ^ inch
thick, left rough from the saw, are generally used. The changes of temperature produce opposite
effects on the wood and concrete. For general purposes strips are not necessary for grooved work,
as the grooving to a certain degree forms the surface into sections, or a series of blocks, which have
a tendency to counteract cracks. Where the foundations are weak, the resultant cracks in grooved
work generally settle or form at the deep parts of the grooves, and are often scarcely noticeable to
the eye.

Another method of forming joints is by cutting with a wide chisel or a cutting tool before the
rough concrete is set, a corresponding joint being cut in the fine concrete topping. False joints are
made by indenting the topping after it is trowelled. A metal roller is used for finishing true joints
and forming false joints. Frames strong enough to resist the expansion of the concrete would not
only increase the density and strength of concrete paving and blocks, but also effectually prevent its
cracking.

Another method for forming sections in large surfaces of pavement or floors to prevent cracks
is effected thus : — First set out the size of proposed sections on the rough or first coat, then with a
straight-edge, a wide chisel, or a cutting tool and a hammer, cut through the rough coat, so as to
divide it into sections as .set out. This done, insert wood strips into the cuttings, keeping their top
edges about \ inch below the screeds or rules which represent the finished surface. The strips are
made from \ inch to i^ inches wide, ^-i inch thick, and in suitable lengths. The width is regulated

stable Pavements.

477

according to the thickness of the paving. For instance, for 2-inch paving the widths should be if
inches. This allows about \ inch in the rough coat (with \ inch play from the bottom), and about
I inch in the topping, and \ inch for the upper thickness of the topping to cover the top edges of
the strips. After the strips are inserted the rough coat is beaten up or made good to the sides of
the strips, and then the topping is laid and trowelled in the usual way. The surface joints are then
made directly over the strips, with the aid of a straight-edge, so as to form a clean and sharp joint.
As already mentioned, these strips allow for any .subsequent contraction or expansion, thus avoiding
zigzag cracks ; and in the event of repairs, or taking up for repairs to underneath pipes, each section
can be cut out and relaid separately without injury to the adjoining sections. This process of
inserting strips in the rough coat, cutting nearly through the topping, gives the same results as if
the strips were laid flush with the surface of the topping, with the advantages that the surface can
be more readily trowelled, and is more pleasing to the eye, because the strips are not seen. A
cutting tool is a blade of steel about 5 or 6 inches long and 4 inches wide, with a wood handle at
one end. The section of the blade is well tapered, so as to obtain a sharp cutting edge, and form a
wide top edge to offer a broad surface for the hammer while being beaten.

Washing Y.VRDS. — Eureka concrete being of a hard nature, and having a close and smooth
surface, is well adapted as a flooring for all washing
or cleaning purposes. The surface being smooth,
it can in turn be readily cleaned. Illustration 190
shows the half plan of washing yard with the plan
and section of grooving, and the fall for a yard for
washing carriages, &c.

Stable Pavements. — The paving for stables,
and other places for keeping animals, should be
jointless, non-absorbent, hard, and durable. Such
paving must not be slippery, yet smooth enough
to be easily washed, the whole laid to falls, and
grooved to give an easy and ready passage for liquid
manure and water when being washed. No material

can so fully meet these requirements as a well-made and well-laid concrete. Granite setts are hard,
but slippery. Bricks are too absorbent ; the urine percolates between the joints and generates
ammonia and other effluvia which are detrimental to the health of animals. The following is an
extract from Report by Dr Ballard, of the Local Government Board, Whitehall, London, S.W.,
1892, in an Inquir\' as to Effluvium Nuisances : —

" The flooring of the stable should be of such materials and so laid as to permit the ready
flowing away of the liquid manure from the standing of the animal. For this purpose the flooring
should be as even and uniform as possible, and such as is incapable of absorbing urine or other
liquids that may fall upon it. Hence the best flooring theoretically is one which is jointless, firm,
and properly sloped to a proper channel. The worst sort of paving that I have seen in ordinary-
use is that made with round pebbles laid upon the unprepared ground. Brick is too absorbent to
make a good pavement ; square stone setts, and what are termed ironstone bricks, laid upon a
duly prepared foundation of cement, are better, but even these are not equal as a flooring to a hard
cement. The flooringf of a slaughter-house should be of some uniform material, sufficiently even to
be capable of read)- and thorough cleansing with water and a brush, and sufficiently rough to avoid
slipping on it. At the same time it should be firm, and incapable of giving way under the fall of

190. — H.Ai.K I'l.AN OF Coach Varp, u;
Section throucii Centre.

478

Plastering — Plain and Decorative.

beasts, or of breaking under rous^h usage. Paving with York flagstones set with cement is the
paving most commonly met with both in London and in the country' ; but the objections to it are
its slipperiness when blood and other matter from the animals slaughtered become spilt upon it,
the tendency there is to the cracking and loosening of the stones (when blood or other liquids may
percolate between them and through the cracks), and the frequent loosening and breaking away of
the cement with which they are set. The best paving of all is an even, jointless paving sufficiently

hard and firm to resist rough usage, and sufficiently rough not
to be slippery. For example, I recently saw at Newcastle-on-T}'ne
seventeen slaughter-houses forming an abattoir, constructed in
1869 by a private company, and which have been in use ever
since for the slaughter of horned cattle and sheep. The flooring
of these and of the approaches to them is made of cement, laid
by W. B. Wilkinson & Co., of Newcastle. It had worn admirabl)',
was free from slipperiness, and had not cracked anywhere. It
was readily cleaned, and was as perfect a flooring for a slaughter-
house as could be devised. The butchers using the slaughter-
house spoke of it in the highest terms of commendation.
Ordinary asphalte is unfit for use in slaughter-houses; it is too

I-1-n-"-"-"-'-;-;-tj soft in summer, and readily yields to blows or pressure. It has

' — — ' been a failure wherever I have seen it laid down."

No. 191.— Plan oi- Stable Floor. Illustration No. 191 shows the method of grooving stalls and

gangways. A is the gangwaj', which can be coloured red or buff
if desired. T\\o designs of grooving are shown. 1! is the main channel ; E is a stable pot ; C is the
side or diagonal groove ; D is the centre groove. A plain margin is left around each stall to
permit of easy cleansing. The blocks in the gangway formed by the cross grooving are 10 inches
by 5 inches. Cross grooving affords a foothold both front and sidewaj's. This method is well
adapted for crossings and gateways, as it affords a foothold for pedestrians crossing, as well as for
horses. For cross grooving, make the long grooves first and the cross grooves afterwards.

Illustration No. 192 shows the
\ — c' — > i^ ^ ^^ '^ ~^ sections of the various parts of above

diagram. Stables are generally laid with
a fall toward the main channel. The
amount of fall varies according to ideas
of the horse owners. The fall adopted
b>' the War Office is i in 80 from the
top of the manger to the main channel,
and I in 36 from each side of the stall
to the centre groove. The width of the
main channels is usually set out with
screed rules, which also act as screeds to work from. Channels are generally formed after the
other surface is finished. Sometimes templates are fixed on the bed of the channels, and the
space filled in and ruled off with a straight-edge while the whole surface is being formed. The
thickness of stable pa\ing varies from 2 to 3i inches, according to the class of horse. The thickness
of the stalls is often decreased towards the manger. Fine examples of grooved work are to be seen
at the Windsor Brewery, executed by G. Morris, the foreman of the concrete layers.

/Section, of CJtanitrL o? B
'« 9'

'■'li''

' stiff r/ravrs C

T :_V. - JVi:'.,-^^J ---

ChanneCuilh iron arn7f

^tctior* ^f Cfntrt frovei 2)

No. 192. — Sections of the various Parts of the Stable Floors
SHOWN ON Illustration No. 191.

Brewery and Dairy Pavements. 479

Brewery Pa\EMENTS. — The paving of bre\ver>- floors requires not only to be hard, but must
resist the action of beer and yeast. Great care must be taken that the concrete is thoroughly set
and dry before contact with beer takes place. The floor for mash-tun, hop-rooms, fermenting backs,
cooling backs, tun-room, &c., should have the topping strongly gauged to stand the effects of beer,
and the heavj- wear caused by rolling barrels, especially when moved on their edges. Two parts of
Portland cement to 3 of fine aggregate is the usual gauge. A further protection against the action
of beer is obtained by coating the surface with acid-proof solution as given in the Appendix. Fer-
menting and cooling backs, also stillions, malthouses, and granary floors, are best constructed in situ.
They are generally formed with a structural thickness of coarse concrete, and the upper surface laid
with Eureka concrete. These floors are not only fireproof, but are also impervious to moisture,
acid, and vermin. Fine examples of brewery floors are to be seen at Man, Grossman, & Paulin's
Breweries, London. David Xicols was the foreman concreter, and the cement was supplied by
Messrs Francis & Co., Nine Elms, London.

D.\IRV AND Food Factory Pavements.— Fine concrete is undoubtedly the most suitable
material for forming floors, table tops, shelves, and tanks in dairies and food factories, &c. Owing
to the hard and impervious nature of concrete it is absolutely sanitary, and easily made with a
dense and smooth surface. It can be washed as readily and as clean as china or glazed earthenware.
Tanks and table tops, however large, can be made in one piece, as also floors, thus avoiding joints,
which are unavoidable with other materials. It is a well-known fact that any material which is
porous or jointed affords a harbour for damp, dust, and microbes. No such defects, however, are to
be found in well-made and well-laid fine concrete. Many of the principal dairies, sweets and potted
meat factories in London and the provinces are paved, and have their working surfaces formed with
fine concrete. The paving for this class of work is best laid as described for Eureka paving, and
the table tops and tanks as for benches and tanks. An extensive and excellent example of this
class of work can be seen at Barratt's Factory, Wood Green, N. This work was executed by the
Patent Paving Company, and Frank Jay was the foreman of the concrete layers. Another im-
portant example is that of B. Harris's Bacon Factory, at Calne, Wilts, executed by Messrs Homan
& Rogers. Walter James was the foreman of the concrete work. Numerous extensive works of
this class have been executed by Messrs W. B. Wilkinson & Co., the Imperial Stone Company,
B. Ward & Co., and other firms of note.

Staffordshire Stone Paving. — This paving is the invention of F. B. Wrightson and W.
Metcalfe, who obtained a patent for this material in 1S95. According to the specification, it is com-
posed of Portland cement and scharff, which are chemically combined so as to produce a hard and
impervious substance. Judging from the samples and tests, this paving is exceedingly hard and
impervious. Owing to the great variety of colours to be found in the aggregate used in this
material, it is well adapted for the formation of mosaic paving.

Petrura Paving. — This is the latest invention in patent paving, being patented in 1S96 by
W. Millar and O. J. Owen. This paving combines all the hardness and impermeability which are
obtained by the use of the aggregates commonly employed in the various patent pavings of the
past, such as granite, slag, stone, &c. In addition to the qualities of hardness and imper\iousness,
it has the great advantage of being non-slippery. This is an important feature, being one which is
the only objection to most of the patent pavings of the past. It is also practically noiseless, thus
forming a perfect paving. Being chiefly composed of a waste or by-product, it can be sold at a
comparatively low price. Combining the minimum of cost with the maximum of quality, it will
doubtless be a welcome addition to the present-day pavings.

48o Plastering — Phnii ami Decorative.

Summary ok Paving " in situ." — Havint; now dcsciibed the various materials, parts, and
processes of paving, the whole may be summarised as follows: — i. Setting out the levels and falls.
2. Preparing the bottom. 3. Laying and wetting the foundation. 4. Laying the screeds to the
desired levels and fall.s. 5. Gauging and laying the materials. 6. Ruling, patting, and trowelling
the surface, and also grooving, indenting, or matting, if required. 7. Protecting and wetting the
work until thoroughly set and hard.

Concrete Slab.s. — Concrete slabs arc now extensively used in London and the provinces bj'
borough survej-ors for street paving. The Victoria Stone Company were the earliest manufacturers
of concrete paving slabs. Concrete slabs have now been in use for twenty-five years. Upwards
of 300 miles of footpaths (average 7 feet wide) have been laid with Victoria stone. This artificial
stone was laid on London ]iridge, where the foot traffic exceeds 126,000 passengers per day. This
paving has been laid about six years, during which time many millions of passengers have walked
over it, and yet the wear is so small that it is scarcely measurable. Another portion of the bridge
has been laid with Victoria paving upwards of twenty years, and although subjected to enormous
traffic, the wear is hardly perceptible. The following tabic shows the relative strength of concrete
stone compared with that of various kinds of stone and brick, as per Kirkcald}''s certificate, 1887: —

Table XII.— Crusiiinc Weight per Cubic Inch in Lb.s.

Medvvay Gault Brick ... - 940 Fireclay Brick 4,032

Bath Limestone •■244 | Staffoid Blue Brick . . . . 4,032

Portland Stone, against the bed - - 2,426

Portland Stone, on the bed - - - 2,620

Medway Gault Brick (pressed) - - 2,643

BraiTiely Fall, against the bed - - 2,934

Craigleith Stone 3,iio

liramely Fall, on the bed - - - S,i35

Yorkshire Landing, on the bed - • 5,6l6

Yorkshire Landing, against the bed - SjSjl

Granite, Peterhead - - - - 6,216

Patent Victoria Stone - - - . 8,321

The tensile strain of Patent Victoria Stone has now reached 1,150 lbs. per square inch. The
following table shows the absorptive qualities of various stones, as gi\cn bj' the Committee of
Council on Education, South Kensington : —

Tai;li-: XIII.— Bulk ok Water absorbed with Bulk of Stone per Cent.,

Twenty-Four Hour.s.

Bath Bo.\, ground - - - 17.0 per cent.

Portland, very durable - - - i3-5 .>

Mansfield, moderately durable - - 10.4 „

Craigleith, very durable - - S.o „

Patent Victoria Stone - - - 7.6 „

It will be seen by the above tables that this kind of artificial stone for strength is superior to
most natural stones. It also has less absorbent projicrties, and consequently is less liable to
laminate under severe frost through expansion of the moisture in freezing. There are several other
firms who are now manufacturing concrete paving slabs. There are also a few corporations who
make their own slabs. Slabs are made in various lengths and thicknesses, but generally in one
width. The ordinary sizes for paving slabs are as given in the following table : —

Table XI\'. — Sizes of Paving Slabs.

2 feet 6 inches by 2 feet

2 feet by 2 feet >

2 feet 6 inches by 2 feet [

3 feet by 2 feet i^ " '"^''^= '^'''^-
3 feet 6 inches by 2 feet '

3 feet by 2 feet /

, . , , ^ ^3 inches thick.

3 feet 6 mches by 2 feet

4 feet by 2 feet

Making Concrete Slabs. 481

The most useful length is 2 feet 6 inches. They can be cut with a chisel as easy as cutting
York stone. Special slabs can be made for circular work, also with rebated sinking for metal
plates, to cover coal-holes, drains, gas and water taps, &c. Concrete paving slabs are laid in
precisely the same way as natural stone.

Concrete Slab Mould.S.— Slab moulds are made with li-inch boards ledged together.
On this ground, wood sides and ends (each being 2], inches by 2 inches, or 3 inches by 3 inches
according to the desired thickness of slab) are fixed. One side and end is held in po.sition with
thumb-screws, which fit into iron sockets, so that they can be unscrewed to relieve the slab when
set. The bottom and the sides and ends are lined with strong iron or zinc plates.

Name-plates for concrete slab moulds and fibrous plaster slab moulds, also hand stamps for
forming names in concrete paving, are manufactured by A. Gilchrist, of Glasgow.

Sl.\B Making. — Slabs are mostly made by machinery. The materials are I part of Portland
cement mixed dry with 2\ parts of crushed granite and slag in equal proportions that have been
washed and passed through a |-inch sieve. They are thoroughlj' incorporated together in a
horizontal cylinder worked by machinery, a minimum of water being added, and the mixing
continued until the mass is well gauged. The mould, which has been previously oiled, is placed or
a shaking machine, known as a " trembler " or " dithercr," which gives a rapid vertical jolting
motion to the mould and its contents. A small portion of "slip," i.e., neat cement, is laid round the
angles. The machine is then started, and the concrete laid on the mould by small shovelfuls at a
time, a man with a trowel spreading it over the mould until full. The surface is then ruled off. If
both sides of the slabs are required for use, the upper surface is trowelled. The whole operation of
mi.xing, filling in, and ruling off takes about seven minutes. The filled moulds are removed and
allowed to stand for about three days. The slabs are then taken out, and stacked on edge and air-
dried for about five days. They are then immersed in a silicate bath for about seven daj's, and are
afterwards taken out and stacked in the open air until required for use. They should not be used
until three months old. Paving slabs are also made by hand, bj- ramming and beating the moist
concrete into the mould with an iron hand-float. Powerful ramming, trituration, or violent agitation
of the gauged materials in the mould, tend to consolidate concrete, and it is possible to further
increase its homogeneity by the use of hydraulic pressure. The above is the method that 1 used
when manager for the Wilkes' Patent Flooring and Eureka Concrete Company. There are a large
number of slabs which are not immersed in a silicate bath, but are simply immersed in clean water.
The Victoria stone slabs are all hand made. The Imperial Stone Company make their concrete
paving slabs by machinery. They are dense and hard, and impervious to moisture. This Company
also lay paving in situ.

Indurating Concrete Slabs. — The surface of concrete slabs or other work exposed to
frictional wear may be hardened by soaking in a silicate solution. Silicate of .soda has a great
affinity for the materials of which concrete is composed, and b\' induration causes the surface to
become hard, dense, and non-porous.

The silicate of soda and potash is known as soluble glass or dissolved flint. The soluble
silicate is a clear viscous substance, made from pure flint and caustic soda, which is digested by heat
under pressure in Papin's digester. Its strength is technicallj- known as 140° Twaddle, which
shows 1,700 on a hygrometer. When used as a bath for concrete, it is diluted with water, the
proportion varying from 6 to 10 parts of water to i o{ silicate. Concrete pavements, laid in situ,
may also be hardened by washing with silicate solution. They should not be silicated until two
days after being laid, to allow the moisture to evaporate and the silicate to penetrate.

482 Plastering — Plain and Decorative.

Mosaics. — The art of making mosaic is at the present time scarcely within the province of
jilasterers, but in former times manj- kinds were made /// situ or in slabs bj- plasterers. The
subdivision of labour has to a great extent cau.sed mosaic making to be confined to specialists.
Concrete mosaic is still made b>- plasterers. A brief description of this and ollxr kinds ma\- j^rove
useful as well as interesting, especially to plasterers who are in the habit of fixing tiles and working
in concrete. Mosaic is the art of producing geometrical, floral, or figure designs, by the joining
together of hard stones, marbles, earthenware, glass, or artificial stone, either natural!)- or artificially
coloured. The term " mosaic " embraces a wide range of artistic processes and materials for the
decoration of floors, walls, and ceilings. The Eg\-ptians were experts in mosaic. The Cairo
worker as a rule had no drawings made beforehand, but the mosaic design was constructed by the
artist as he arranged the pieces on the ground. The mosaic pavements of Cairo are of a slightly
different character from those used for wall decoration, and are generally composed entirely of
marble tesser.-e (and sometimes red earthenware) of larger size than the delicate pieces that are
included in wall mosaics. Thej- are arranged to form geometrical ]jatterns within a space of about
2 feet square. Each square or slab is made separately, and the pieces are set, not in ])lasler, but
in a composition of lime and claj- impervious to water. The cla\- must be unburnt, just as it comes
from the pit. Mosaic slabs for walls and pa\ements from Egypt are to be seen in the South
Kensington Museum. Saracenic mosaic in Egj-pt is a combination of the tesselated method with a
large proportion of sectile mosaic. The Romans also were great workers in mosaic. The mosaics
of Byzantium and Ravenna consisted of cubes of opaque and coloured glass.

In the Museum of Practical Geology there are fragments of old Roman mosaic pavements of
the time of the Republic, also tools used bj- the workers in Roman mosaic, and the stucco which,
when mixed with linseed oil, forms the cement for fixing the tesserje. There are also loose tessera:
from Jerusalem, Pompeii, Algeria, and Greece. Very fine examples of Greek and Roman mosaic
are in the liritish Museum, and in the (luildhall are exceedingly interesting Komano-British
mosaics found in London.

The general method used in England for ]ia\ement mosaic is as follows: — The repeated design
is traced on stout paper, and small ])ieces of marble, or more often tile, are gummed on the paper,
following the design of form and colour, one piece at a time (with the smooth face downwards)
being laid until the design is completed. The mosaic slabs, which are thus temporarily kept in
position, are .sent to the building and laid where intended. A rough concrete foundation, which
has previously been laid level, is then floated with Portland or Keen's cement, and the slabs with
the paper upwards are then bedded and beaten and pressed with a hand-float into position. The
paper is then damjjed and drawn off, and anj- openings or defects filled up with small pieces of the
same form and colour as the design. The slabs are made in \arious sizes according to the design ;
for instance, a border 12 inches wide maj- be made from 3 to 6 feet long. When lajing the slabs,
it is best to begin at the centre and work outwards, and any excess or deficiency taken off or made
up in the plain part of the border at the walls. The tiles are made at pottery works in the required
sizes and colours. The thickness is generally about \ inch, and the average surfiice size about
i inch. Females are often employed fixing the pieces on tlie ])aper. Designs of coats of arms,
monograms, dates, figures, flowers, and foliage are effectively produced by this simijle and cheap
process.

Concrete Mosaic. — All mosaics are more or less of a concreti\e nature, and the trade term
of " concrete mosaic " is due to the fact that the matrix used is Portland or other cement gauged
with the marble aggregate, and laid in most cases in a similar manner as ordinary concrete.

Concrete Mosaic. 483

Concrete mosaic is extensively used for paving halls, corridors, conservatories, terraces, &c.
It is also used for constructing steps, landings, baths, pedestals, &c. A. C. Hobman, of
London, was one of the early pioneers of the manufacture of concrete mosaic, and his mosaic
has been extensively used. It is remarkable for beauty and variet>- of design, durability and
perfect polish. Drake, of London, iDrought concrete mosaic to great perfection. Messrs
Williams Bros. & Co., of London, are noted for their artistic mosaic. I have made a
large quantity of concrete mosaic for pavements, steps, landings, balustrades, mouldings,
vases, figures, and many other purposes in connection with decoration and buildings, and
also made imitations of red and grey granite. Slabs and tiles made of this class of mosaic
for paving purposes are slowly but surely proving a formidable ri\al to Italian mosaic and
encaustic tiles. It can be made in larger sections, thus facilitating rapidity of laying. It is
more accurate in form, durable, non-slippery, and cheaper. The last reason alone is a favourable
item in this keen age of competition. Where marble has been scarce, broken tiles, pottery,
coloured glass, flints, white spar, &c., have been used as an aggregate. If the marble chips are
obtainable as a waste, and near the place of manufacture, the primary cost is small. If the
moulds are of metal, and made in sections so as to form a series of moulds in one case, and the
casts are pressed by means of hydraulic power, the cost of production is reduced to a minimum. If
the casts are polished in large numbers by machinery on a revolving table, the total cost is further
reduced. For local purposes the)' can be made by hand at a medium cost. Slabs are made in
almost any size, but generally from 4 to 6 feet superficial. The thickness varies from I to li inches.
Tiles are usually made about 10 inches square and I inch thick. The tiles are generally made
with a face of cement and white marble, or white and black marble chippings. They are backed
up with a cheaper aggregate. Various tints of the face matri.x are obtained by mixing the cement
with metallic oxides. The tiles are made in wood or metal moulds, with rhetal strips to form the
divisions of form and colour in the design. If the design is fret pattern, the gauged material is
put in between the strips that form the band of the fret. When the stuff is nearly set, the strips
are taken out, and the other part filled in with another colour. Sometimes the bands or running
design are cast in a separate mould, and when set, placed in position in a larger mould, and the
ground filled in, covering and binding the whole in'one tile. Another plan is to lay a thin coat of
cement on the face of the mould, forming the design with small marble chips by hand, b)' pressing
the marble into the cement as desired. When it is firm, it is backed up with the ordinary stuff, and
when set, they are ground and polished.

Concrete Mosaic laid "in situ." — Pavements for halls, passages, shops, landings, &c., are
also done in situ. A rough concrete foundation is first laid fair to falls and levels within i inch of
the finished surface line. This h inch space is to recei\e the plastic marble mosaic. The main or
centre part is generally done first, and the border last. This allows a walking space or a bearing
for boards, laid from side to side, to work on when laying the centre. A plank sufficiently strong
to keep one or two cross boards from touching the work is laid along each side. On the side planks
the cross boards are laid, and moved about where required. The width of the border is marked on
the floor, and wood screed rules laid level to the marks to form a fair joint line for the border, also
as a screed when floating the centre part. The screed rules are generally fixed with gauged plaster
which is quicker than fixing on gauged cement. After the centre is laid, the plaster should be care-
fully swept off, and the concrete well wetted before the border is laid. The marble and cement is
gauged in the proportion of 2 of marble to i of cement, and laid flush with the screeds, laying and
beating it in position with a long wood hand-float. The surface is ruled in from screed to screed

484 Plastering — Plain and Decorative.

with a straight-edge. The surface is then ironed with a lading trowel until it is smooth and fair.
If the marble does not show, or is not regular, or is insufficient, the bare parts are filled in with
marble by hand. When marble is scarce, the | inch of the top surface is laid in two coats, the
first coat being composed of cement and a cheaper aggregate, such as broken stone, tiles, &c., and
gauged in the same proportion as the upper or marble coat. It is laid about \ inch thick, and when
it is firm, but not set, the marble coat is laid as before directed. The first coat saves the marble,
and being firm, tends to keep the marble in the upper coat from sinking. The top coat is some-
times sprinkled over with fine marble chips by hand or through a fine sieve, then pressed into the
surface and ironed with a laying trowel. Before ironing the surface, care should be taken that the
chips are equallj- distributed, al.so that their flat surfaces are uppermost, and that the matrix and
chips are perfectly solid and free from ridges or holes. After the centre is laid and screeds removed,
the border is laid in a similar way. If there arc two or more colours or forms in the border, the
divisions are formed with narrow screed rules, and arranged so that as many as practicable can be
laid at the same time. This allows the various parts to set at one time, and saves waiting for each
separate part to set. The screed rules for circular work or angles are formed with strong gauged
plaster and then oiled.

The marble chips are either broken b}- hand or in a stone-breaking machine. The chips vary
in size from y^ to \ inch. The best colours for borders are a black matri.x; with white marble
or spar chips, or a white matrix with black marble chips. The white matrix is obtained by
mixing the marble dust (produced when breaking the marble into chips) with a light coloured
Portland cement. The centres can be made in various tints, but the most general is a warm red
which is obtained by mixing the cement with red oxide. Cement coloured with red oxide should
be laid first, as it is liable to stain other laid parts of a lighter colour. When the centre and border are
laid, the floor is left until the whole is perfectly set and hard, and it is then fit to polish. This is done
by means of a stone polisher, water and marble dust, or fine slag powder. The stone polisher is a
piece of hard stone from 8 to 12 inches square, and about 3 inches thick, into which an iron ring is
inserted and secured with lead. A wooden handle from 4 to 6 feet long, with an iron hook at one
end, is inserted into the ring, .so that the handle is firm on the stone, jet has sufficient play to be
moved freel)- backwards and forwards. The polishing should not be attempted until the stuff is
thoroughly .set, because the polishing will destroy the face of the cement, and cause a vast amount
of extra labour in grinding the surface down until free from holes. Small parts of the gauged stuff
should be set aside as tests for determining when the stuff is set. Concrete mosaic, where economy
is desirable, will make a strong, durable, and waterproof floor, and an excellent substitute for higher
class mosaics.

Roadways. — It is passing strange that in this progressive age, a safer, more expeditious, and
less costly plan than the present is not generallj' adopted for the la}-ing and repairing of pipes,
drains, and wires. Several methods have been proposed, and partly carried out, to improve the
tedious, vexatious, and costly methods now in use. The patent impervious concrete roadway
patented by Mr C. R. Williams, A.M.I.C.E., seems to have many good points for the formation of
new roadways. By this patent, passages are constructed beneath the permanent way, along which
gas, water, compressed air pipes, telegraph, telephone, and electric wires are laid ; beneath this floor
arches and concrete tubes are laid for the sewage. The passages are reached by openings covered
with movable concrete slabs. By this method the cost and annoyance of digging up and repairing
the roads and stopping the traffic whenever pipes, wires, or drains have to be repaired or altered, are
obviated.

CHAPTER XIX.

CONCRETE— Continued.

Concrete Staircases— Cast Concrete Stairs -Tests of Steps— Concrete Stairs formed "in sitc "—
Setting Out Stairs— Nosings and Risers— Framing Staircases— Centring for Landings and
Soffits— Waterproof Centring— Staircase Materials— Filling in Stairs— Finishing Stairs—
Non-Slippery Steps— Striking Centrings— Concrete and Iron— Setting Concrete Soffits-
Fibrous Concrete— Polished Soffits— Concrete Staircases and Fibrous Plaster— Dowel
Holes— Summary of Staircases constructed "in situ"— Cast Steps— Treads and Risers-
Closed Outer Strings— Concrete Floors— Plaster Floors— Joist Concrete Floors— Caminus
Concrete Cement— Concrete Floors and Coffered Ceilings — Combined Concrete Floors
and Panelled Ceilings- Concrete and Wood— Concrete Slab Floors— Construction of Slab
Floors— Hollow Floors— Concrete Roofs— Notes on Concrete Floors, etc.— Cast Concrete-
Concrete Dressings— Mouldings Cast "in situ"— Modelling in Fine Concrete— Concrete
Fountains — T.\NKS, Sinks, Garden Edging, V.\ses, Chi.mney-pieces — Coloured Concrete-
Fixing Blocks, Lintels, Walls, Strong-Rooms, and Coffins— Stonette— Tile Fixing— Patent
Non-Slippery Steps.

Concrete Staircases. — A good staircase is one of the essential features in a building. The
safetj- and convenience of persons using a staircase are not onl)- affected by the due proportions
and arrangement of the steps, but bj- the strength and fire-resisting properties of the materials
emplojed, and the manner of construction. The \vells are in many cases too small, out of
proportion to the structure, which necessitates dangerous winders, tiring high risers, narrow treads,
or insufficient headway. Some architects when designing a staircase pay little attention to the
practicability- of construction. What maj- seem easy in theorj- or on paper is often found imprac-
ticable or unnecessaril)- difficult when reduced to actual practice. The errors of commission
and omission are left for the workmen to contend with and overcome as best they may at the
employer's expense. Happily such cases are few, the majority of architects supplying figured
drawings, which are not onl}- a help and guide to the workmen, but also ensure a practical staircase
in due proportion and without unnecessary expense. Staircases should be spacious, light, and easy
of ascent. It is generally admitted that a 12-inch tread and a 6-inch rise is the most convenient,
and that no tread should be less than 8 inches or more than 16 inches, and no rise less than 4^ inches
and more than 7 inches. According to Blondel, the rise should be reduced \ inch for ever\- inch
added to the tread, or the tread reduced by i inch to every \ inch added to the riser, taking a 12-
inch tread and a 6-inch rise as the standard. Treads may be increased by means of a nosing, which
usually projects from i inch to i i inches. Nosing not only gives more available space for the tread,
but also affords some advantage to persons going down stairs, as the heel cannot strike against the
rising. In setting out a flight of stairs, the tread of the steps are measured from riser to riser.
Where practicable, the number of steps from landing to landing should be odd, because when a
person begins to ascend with the right foot first (as most people do) he should end with the same
foot. Rectangular steps are called fliers. Winders, being narrowed at one end, are aKva\-s more
inconvenient and dangerous than straight steps, and should not be used for public buildings or other

486

P/asfcriiig — P/ai)/ and Decorative.

places where there is a crowded traffic. Winders are also more expcnsi\e to construct. The
Education Department prohibits winders in schools, and the London County Council folknvs the
same rule. The)- are, however, unavoidable in circular staircases, al.so in some instances in angles,
where a quarter or half space landing would not gi\e the desired ri.se. Winders should be so made
that the tread 6 inches from the end of the narrow ])oint should be wide enough to step upon \\ ithout
danger of slipping. No stairs should be less than 3 feet from the wall to the hand-rail. A width of
3 feet 6 inches will allow two persons to walk arm-in-arm u]j or down stairs. A width of 4 feet
6 inches is generally u.sed ; this gives plenty of space for two persons to pass each other. No hard
and fast rules can be laid -down for the size of treads and risers, as they are regulated more or less
b)- the size of the well and the height from floor to floor. Too few steps in a flight arc as bad as too
many. There should not be less than three. Long straight flights of steps are tiring and dangerous.
The straight line of length should be broken by landings, so that there may not be more than
eleven continuous steps. Landings give ease in ascending and safety when descending. No landing
.should be less in length than the width of the staircase. The staircases in pre-Elizabethan England
were usually plain, dark, and in long narrow flights ; but with the Elizabethan architecture came in
a more commodious, light, and decorative stjde. Wood stairs are often enriched with plaster work,
the soffits being panelled with plaster, and the strings adorned with composition or plaster enrich-
ments. Stone stairs are also frequently enriched with plaster mouldings in the angles of the soffits
and walls. External steps and landings are usually made with a fall of \ inch to the foot to allow
rain to fall off. The following table of the sizes of external and internal steps of various public and
private buildings in London are taken from actual measurement. The dimensions are given in
inches. T denotes the tread, R the rise, and N the nosings.

T.VIILE XV. — SiZE.S OF Step.s.

External Stehs.

Internal Steps.

f West Portico
St Paul'sCathedraK

\ North Uoor

>5
14

5
5i

Natural History Museum
Grosvcnor Gallery -

14
12

6
6

British .Museum

■5*

Tivoli Music Hall -

12*

Natural History Museum -

i6i

House, Russell Square -

loi

•i

St Martin's Church -

1 3*

—

West End House -

Farringdon Market -

—

„ „ Attic Stairs -

Duke of York Steps -

—

' Suburban \'illa

House, Bedford Square -

■i

Small Houses - - - -

Cast Co^'CRETE Stairs. — Concrete is now fast superseding stone, wood, and iron for staircase
construction, where strength, durability, economy, and fire-resisting properties are required. Cast
concrete stairs were first introduced by Mr W. B. Wilkinson, of Newcastle, nearly sixty years ago,
and first used in London by Mr M. Allen in 1862. The stairs were cast in single steps, or in treads
and risers, and fixed in the same way as natural stone. Mr Allen used shingle and coke-breeze as
aggregates. Square and spandril steps, risers, and treads are cast in wood moulds ; circular steps
and curtails in plaster moulds. Spandril steps should have the wall or " tail " end formed square.

Constructing Concrete Staircases. 487

and about 4i inches deep, to give a better bed and bond in the wall. A good mixture is 3 parts of
granite or slag chippings and i of Portland cement, gauged stiff, and well rammed into the moulds.
When set, the)- are removed from the moulds, air dried, and placed in water or a silicate bath, and
treated in a similar way to that described for slabs. For long steps, pieces of T iron or iron pipes
are sometimes inserted in the centre of the concrete while being cast. The iron is not actually
required to strengthen concrete properly made, but is used to give a temporary strength to the cast
while it is green, so as to allow more freedom and security in handling the cast when it is being
taken from the mould and mo\ed about till permanently fixed. Landings are cast in a similar waj-,
but unless \-ery small, they are best done in situ. I have made landings up to 40 feet superficial, but
owing to the cost of transit, hoisting, and fixing, they were not profitable.

Tests of Steps. — The following examples show the strength of concrete steps: — In
German}', when constructing a concrete stair, with square steps 3 feet 4 inches long, 14-inch
tread, and 6^7-inch rise, and one end set 8 inches into the walls, four steps were submitted for
trial, and 5.940 lbs. weight of iron was gradually piled on them. The steps showed no signs of
fracture, but no more weight could be put on because the masonry began to j-ield. The load was
left on three days, and the steps remained unaffected. Although numerous tests have been
made in England of concrete floors and blocks, few have been made for concrete stains. The
following ma\- be given as a reliable one : — When manager for Wilkes' Metallic Flooring and
Eureka Concrete Compan)^, I had several concrete steps tested bj- Mr D. Kirkcald)-, which gave
highly satisfactorj' results. When constructing staircases with concrete steps at the Parmiter
Schools, London, Messrs T. Chatfield Clarke & Son, the architects, required e\ery step to be tested
before thej- were built into the walls. The steps were about 6 feet long, ii-inch tread, and 6-inch
rise. E\-ery step was tested in the presence of the clerk of works and P. Storrier, the foreman
concreter, and the author. The steps were supported at both ends, and weighted with a distributive
load. The majorit}-, which were matured by age, passed the specification standard, while a few,
which were green, broke with a load considerably under the standard. A similar step, but full)'
seasoned with time and water, was exhibited at the Building Trades' Exhibition at the Roj'al
Agricultural Hall, 1887, where it carried a distributed load of 8,832 lbs. without a sign of flaw.
Tests of concrete slabs, &c., are given in Table XVI., page 504.

Concrete Stairs formed " in situ." — Concrete stairs are an outcome of stairs built with
cast concrete steps. Stairs formed in situ were introduced by the author in 1867, and first used on
a small scale on the Redcliffe estate, West Brompton. The idea was suggested bj- the use of
reverse moulds for fibrous plaster work, and in the formation of concrete dormer windows made in
situ on some of the mansions in Redcliffe Square. The step landings and the wall bond, being a
monolithic structure, are to a certain degree self-supporting. They tend to strengthen instead of to
weaken the walls. Architects generally sup])l\- drawings of the intended staircase, but as there is
often a difference in the size of the details of the actual work and the drawings, it is necessarj- that
the workman should ha\e a practical knowledge of setting out the "height" and "go" for the pitch
board, to suit the landings and the well of the staircase, and ensure the necessary head-room.

Settinc; Out St.^irs. — A correct method of setting out the framing for concrete stairs is of
primary importance. The height of a stair is the length of a perpendicular line drawn from the
upper surface of a floor to that of the one immediately above it. The "ingo," or "go," is the length
of a horizontal line drawn along the centre line of the flight of steps or stair space. The exact
height and widths should be taken on a rod, which should afterwards be u.sed for setting out the
w ork. Never work without this rod, as it is quicker and more accurate than measuring with a

488

Plastering — Plain ami Decorative.

Fig. I.

Xo. 193. — Sections of Nosing
Moulds with Riser Boards.

2-feet rule. There are various ways of getting the dimen.sions of treads and risers. The following
is a simple one, and answers for most purposes. The height and go are taken and suitably
divided. For example, if the height from floor line to floor line is 9 feet 3 inches, and it is proposed
to make each riser 6 inches high, reduce the height to inches, which would be in ; divide by the
proposed height of each step — 6 inches — the quotient will be 18, with 3 remaining. This gives 18
steps of 6 inches, plus 3 inches. Divide this remainder over the number of steps, which gives the
quotient 6f^ inches, or 6\ inches, which is the exact height of each step. Another way is to proceed
as first mentioned above, and divide the whole height, iii, by the number of the steps, 18, giving
the same quotient 615. If there are intermediate landings or half spaces, their dimensions must be
allowed for. The size of the tread is obtained by dividing the ingo by the number of steps.
The quotient will be the width of tread. Great care should be taken in setting out the rods and
pitch boards. It is better to measure thrice than to cut twice. When the string line is marked on

the wall, a chase about 4^ inches deep is cut into the wall. It is
not necessary to cut the chase straight at the soffit line, as it is apt
to cut into a half, or rather a whole brick, and leave the ends loose.
The irregular line of chase below the soffit line can be made solid
during the process of filling in the steps. The chase should be cut
as the work proceeds. Not more than f)ne flight at a time should
be cut, to avoid weakening the wall. In some instances a brick
course in sand is left by the bricklayers. The bricks are then taken
out as the work proceeds.

Nosings and Risers. — Nosing mouldings should be strong
and bold. A simple but well-defined moulding not only gives
greater strength, but is more in keeping with its purpose than one
with numerous or small members. Nosing and riser moulds are
best formed in two parts, the nosing mould being one part, and the
riser board the other. To cut them out of the solid would not only
be expensive, but also cumbersome to fix. They can be run at
most saw and moulding mills. They should be run in lengths,
and then cut and mitred on the job. Illustration No. 193 shows
various forms of nosings. Fig. I is a simple nosing for common
work. Fig. 2 may be used for school stairs, &c. Figs. 3 and 4 are
well adapted for a good class of work. It will be seen that the
lower edges of the riser boards are spla\ed. This is to admit the shoe of the running
mould, also a trowel to work close up to face of the concrete riser when running and trowel-
ling off the treads. The dotted lines indicate the line of tread. Nosing moulds are sometimes
cut in the centre of the section, and afterwards the two parts are held in position with screws while
the steps are being filled in. This allows the upper part to be unscrewed and taken off when the
stuff is nearly set, thus allowing more freedom to trowel the surface of the tread, also to make a
better joint while the stuff is green, and at the part that is cast and the part to be trowelled. The
joint in the nosing mould leaves a thin seam which is easily cleaned off, whereas the joint of the
tread and nosing is not only seen more, but is also more difficult to make good. Illustration
No. 194 shows the mould and joint and screws for fixing same.

Framing St.\ircases. — The wood framing for concrete stairs differs from, and is partly the
reverse to that used for wood stairs. The nosings are formed the reverse of the moulding, and the

No. 194.— Jointed Nosing Mould
WITH Riser Board.

Fraiuiiig Staircases.

489

whole framing is so constructed that it forms a mould to cast all the steps and landings, from floor
to floor, in monolithic form, or one piece. When the positions of half spaces or other landings are
set out on the walls, strong planks are fixed on edge so as to give fixing joints for the carriage and
outer strings. The strings are then fixed to act as guides for fixing the centring, risers, and nosing
moulds. Where practicable, the outer string should be so arranged in the fi.xing that it can be taken
off after the concrete is firm without disturbing the centring. This allows the returned ends of the
steps to be cleaned off while the work i.s green. The carriage boards are fi.xed from landing to
landing. Illustration No. 195 shows the forms and positions of the various parts, with their names.
Bullnoses or curtails and circular parts of nosings are formed in plaster moulds which are run
with several reverse running moulds.

Staircases between walls are more simple than open staircases, therefore the\^ are more ea.sj- to

If !!

No. 195. — Fr.\mino for Co.ncrete Stairs Co.nstructed in siti'.

frame up. The string boards are cut to the reverse of that used for wood stairs. A string is cut
for each wall. The riser boards are then fixed to the wall strings. The centring for the soffits is
fixed Independentl}-, the boards being laid on fillets which are nailed on each wall. For short flights
of steps or common stairs, such as for cellars, &c., string boards may be dispensed with. The
positions and sizes of the risers, treads, soffits, and landings arc first set out and marked on the walls.
Riser fillets are then nailed on the walls, taking care to keep each fillet in a line with the riser mark,
and to allow for the thickness of the riser boards which are subsequently nailed on the inner sides of
the fillets. Riser boards for winders are generally hung on long fillets, and then nailed on the walls.
Long fillets extending upwards enable the work to be easier and more strongly fixed, as they
extend o\'er more brick joints than if cut to the e.xact height of the riser.

Centring for L.vndings and Soffits. — Centring for landings and the soffits of stairs
should be made strong and true. The timber should be well seasoned, to prevent warping or

490 Plastering — Plain and Decorative.

shrinkafje. The outer angles of landings should be supported by strong wood props, not only to
carr)' the immediate landing, but to carry another prop for the landing above. All centrings should
be made perfectly rigid, to stand the weight of the concrete and the ramming. Great care should be
taken that the timber framing is securely supported, as any deflection will not only throw the work
out of level, but will also tend to crack the concrete. The principal props should be cut about
A inch shorter than the e.xact height. They are placed on a solid bed, the \ inch space at top being
made ujj with two wedges, the thin ends being inserted in opjjosite directions and gently driven
home from each side until the exact height is obtained. If it is difficult to get to the top of the
prop, the wedges can be inserted at the bottom. The use of the wedges will be seen when the
centring is struck. If there are winders in the stair, the centring for the soffit will be more or le.ss
circle on circle. This form of centring is done by lathing with i-inch boards cut to a taper, the
surface being made fair with gauged lime and hair. Rough i i-inch boards are used for the
centring. This should be close-jointed. Open joints or sappy timber act as a sieve, and allow liquid
cement to drip through, thus robbing the concrete of its strength.

W.VTERPROOK Centring. — The following is a method that I have used with marked
success for the soffits of stairs, landings, and the ceilings of floors. The initial cost of preparing
is small, and is repaid with interest by the decreased cost of setting and the increased strength
and solidity. For ordinary work, such as warehouses, &c., it is very suitable, as a finished surface
is formed, and no setting required. It seems strange that, when casting concrete work out of a
wood or a plaster mould, the mould is seasoned, and every precaution taken, not only to stop
suction, but also to prevent the escape of liquid cement ; but when casting a large surface in situ
(where every precaution should be taken to obtain the maximum of strength), any kind of centring
(which is a mould) is thought good enough, if only sufficiently strong to carry the concrete till set.
I am aware that many workers in concrete think that an open or porous centring is a benefit
instead of a defect, simply because it affords an escape for excess water. But why have e.xcess
water at all ? There is no gain in time or strength, but a direct loss in both points. The excess
water descends through the concrete by force of direct gravitation, and always carries a certain
amount of liquid cement with it to the centring, leaving the aggregate more or less bare, and
the body of the concrete weak. A part of the liquid cement also oozes through the joints and
crevices, which leaves the skin of the concrete bare and broken. There is no reason or excuse for
excess water, and it is simply the result of ignorant or careless gauging, which is not only a waste
of time, water, and cement, but a loss in the ultimate strength, and the cause of cracks. Porous
centring is also a dirty process. The overhead drip, drip, is neither good for workmen nor the
materials underneath.

The process of forming the rough centring boards watertight is simple and expeditious,
being done by laying the rough board surface with a thin coat of gauged plaster ; and when the
centring has been struck, the plaster will come with the boards, leaving the concrete with a fair
face. The ramming forces a certain amount of water to the lower surface or centring, and this is
so close and fine that it takes an exact impre.ss of it ; consequently, the truer and smoother the
centring, the truer and smoother the concrete surface. The film of water indurates the skin of
the concrete, and prevents surface or water cracks. It will be noticed, when filling in dry or porous
plaster moulds, that the concrete cast produced has a surface either friable when newly cast, or
when dry the surface is full of small water lines, like a map, or a broken spider's web. This is
owing to the suction caused by the porous nature of the mould, and the water escaping through the
weak or open parts leaving corresponding lines on the concrete surface. These defects are

Constructi]ig Concrete Staircases in Situ. 49 1

obxiated by using waterproof centring. Fine examples of concrete stairs finished by this method
are to be seen in Throgmorton Avenue, London. These works were executed by James Nunney,
under the author's supervision.

Where fineness of finish is not required, such as warehouse floors, the surface can be made
sufficiently fair and smooth when filling in the concrete without subsequent setting. The plaster
is laid on the centring and made fair and smooth, and then the surface is saturated with
water to correct the suction, or the surface, if dry, may be brushed over with a thin soap .solu-
tion to prevent adhesion. On this surface a coat of neat Portland cement about J inch is
laid, and on this the concrete is placed. The two unite in one body, and when set, and the
centring struck, the plaster shell comes with the boards, leaving a smooth surface. This surface
can be made in colour by lime washing, which will also gi\-e more light, or a finished white surface
can be obtained by substituting Parian or other white cement for the neat Portland cement. The
concrete must not be laid until the white cement is firm, not set, otherwise the concrete will force
its way in thin or soft parts, and disfigure the surface. I have successfully used this method
for obtaining a finished white surface when encasing iron girders with concrete for firej^roof
purposes.

St.\IRCASE Mateki.vls. — -With regard to the materials for a concrete staircase, no one who
intends to construct them substantially, fireproof, and economically, can afford to use common
substances, when by judicious selection and for a trifling additional first cost a combination of
materials can be obtained, which, if not (strictly speaking) fireproof, is at least the most incom-
bustible constructive compound known. This is a quality of the most vital importance in modern
house construction. Portland cement and slag cement are the best known matrices. The finer
Portland cement is ground, the greater its heat-resisting powers. Slag cement is lighter than
Portland cement, and its fire-resisting proj^erties e.xceed those of both gypsum and Portland cement.
But as its manufacture is as yet somewhat limited, and its strength not uniform, exceptional
care must be exercised in testing its general qualities before using it for staircases. Broken slag,
firebricks, clinkers, and pottery ware are the best aggregates, being practically fireproof All should
be clean, and in various graduating sizes, from that of a pin's head to that of a walnut, for roughing
out with. The topping should be the same as that described for Eureka paving.

Filling in Stairs. — Before gauging the materials, sweep out all dust in the interior of the
framing and the wall chase, and then wet the latter, and oil the woodwork. If the wood of the
nosing moulds and risers is sappy or open-grained, the long lengths, before being cut and fixed,
should be made smooth and indurated by coating with a solution of hot paraffin wax. The
smoother and less absorbent the surface of the wood, the more readih- and cleaner will the mould
leave the cast work. Paraffin also renders the wood damp-proof, thus preventing swelling or
warping. For ordinary purposes one or two coats of paraffin oil will be found sufficient. This
should be done two or three hours before the steps are filled in, so as to allow the oil to parti)' drj'
in and stop the pores of the wood. If the wood absorbs all the oil, and has a dry surface, brush the
surface again with paraffin, using a semi-dry brush. This should be done as the work proceeds. If
the surface is over wet, the oil mixes with the cement, thus causing a more or less rough surface.
Soap solution may be safeh' used for rough concrete, or where a rough surface is left to be
subsequently .set. In tlie latter case, the surface must be well wetted with water and scrubbed before
the final coat is applied. Soap solution may also be used for rough framing, such as soffit boards,
but soap should not be used for fine concrete or a finished surface, as it leaves a film of grease which
has a tendency to prevent the cement adhering when clearing up or making good the finished

492

Plastering — Plain and Decoyative.

surface. As the work of filling in proceeds, the surface should be brushed o\cr with slip, i.e., neat
cement, to fill up all angles, and obtain a surface free from " blubs " and ragged arrises.

The coarse concrete for roughing out the stairs is composed of i part of Portland cement and
3 parts of coarse fireproof aggregate. These materials must be gauged stiff, and laid in small
portions of about a jxiilful at a time, taking care to thoroughly consolidate by ramming and beating
with a wooden mallet, using a wooden punner or punch to get into the angles and deep parts.
When the first la>cr, which may be about 3 inches thick, is rammed, another layer is deposited and
rammed, and so on until the rough stuff is within \ inch of the line of tread. It must not be
omitted to brush the strings, treads, and nosing moulds with slip as the work proceeds. This is
most effectually done by the aid of a tool-brush. Care must be exercised when ramming stairs
with mallets or jjunches that the mallet or other implement u.sed is not too large or heavy, or it

would most likely cause the framing to bulge out,
and the form of the work would be irretrievably
spoilt. During the operation of ramming, some
of the water and a part of the constituent of the
cement is forced upwards, and leaves a thin,
smooth, clayey film on the .surface, w'hich [ire-
vents the adhesion of the ne.xt layer. For this
reason the successive layers should be deposited
before the previous one is set, and the topping
should be laid while the coarse concrete is yet
green. Too much stress cannot be laid Lipon the
importance of topping the rough coat while it
is green. This is one of the secrets of success
of solid and strong work, so no more rough
stuff should be laid than can be topped before
the rough is set.

The fine stuff for the topping is the same
as for Eureka paving, viz., 1 part of cement to 2
of fine aggregate, gauged firm and plastic. The
tread is made level and fair by means of a run-
No. 196.-SECT10NS OF Frami.nt, of Soffit of Stair, Riser ^jng mould .so formed that it bears on the nosing
AND Noser Mould, with Concrete and Tread Ru.n- ,1-, 11

NiNG Mould in Tosition. moulds above and below the tread. 1 he mould

has a metal plate or "shoe" fixed so as to run
and form the tread. The shoe projects so that it will work under the riser board close up to the
concrete riser. Illustration No. 196 shows a section of steps with the mould in position, also a
section of the nosing mould and soffit boards and carriage. The end of the slipper next to the
wall is cut short to allow the mould to run close up to the wall. A section of a T iron is show-n
as sometimes used as an internal support. Iron is used for long steps, or where stairs are intended
for heavy traffic. Iron helps to support the concrete until set ; it is placed in alternate steps, or in
every third or fourth step, according to length of step. Ordinary sized steps require no iron, unless
as a support for the concrete while green, and during the process of making.

Finishing Stairs. — When the treads are firm after being run, the upper part of the nosing
moulds are removed, the surface and joists trowelled off. The advantage of having the nosing
mould in two parts will thus be seen, as it allow-s the joint at this most noticeable part to be

Concrete and Iro/i in Combination. 493

neatly cleaned off while the work is green. The lower part of the mould will support the concrete
nosing during the finishing of the tread, and until the concrete is set. If the work is done with a
nosing mould in one piece, which necessitates its being left on until the concrete is set, the joint has
then to be filed down and stopped, and however well done, has a patchy appearance. When the
treads are finished, and the work set but not dry, the riser and string boards are taken off, the
joints made good, and the returned end of the steps cleaned off If the stuff has been properly
gauged and rammed, there should be little or no making good required, but it is important that if
necessary it should be done while the work is green. A thin layer of neat cement will not adhere
on a dense and dry body of concrete. The only way to obtain permanent cohesion is to cut the
damaged surface out to a depth of not less than \ inch, then thoroughly wet it, brush the surface
with liquid cement, and fill it in with gauged cement. Xo traffic should be allowed on the treads
during the process of setting and hardening. The work is further protected and hardened by
covering with sacks kept wet for several days by frequent watering. Where there are several
flights of stairs to construct, there should not be less than three sets of strings and riser boards, which
will enable the carpenter to fix one set while the plasterers are filling in and cleaning off the others.

Non-Slippery Step.s.— Incessant traffic tends to make the treads of steps more or less
slippery. In order to obviate this, the surface is indented with a concrete roller, similar to that used
for some kinds of paving. Another way is to form three or four sunk V-shaped grooves from'l inch
to 2 inches apart, on the treads while the concrete is moist. Another way is to insert leaden cubes
about I inch square from 2 to 3 inches apart in the surface of the treads. Well-seasoned hard
wooden blocks, about the same size as the lead, and fixed in a similar way, keeping the end grain
vertical, are also used for this purpose. Indiarubber and cork cubes may also be used. Excellent
examples of grooved steps (some cast and some formed in sitit) are to be seen in the stairs leading
from the subway to the grounds of the Natural History ]\Iuseum, and to the station at South
Kensington. This work was done by the Patent Metallic Paving Company. R. Walker was the
foreman concreter for the stairs, and James Hill foreman for the concrete paving in the subway,
the whole being done under the author's supervision. For patent non-slippery steps see page 516.

Striking Centrings. — This should not be attempted until all the other work, with the
exception of finishing the soffits, is done. It will be understood that the framing can be arranged
so that the string and riser boards can be taken off without disturbing the soffit centring, which is
kept up as long as possible. The time for striking centring greatly depends upon the class of
cement used, the manner of gauging and l^tying the concrete, and the temperature ; but generally
speaking, centring should not be struck for at least ten days. A stair between walls can be struck
much sooner than one having only one bearing b)- which its own weight is carried. I have seen a
stair, with steps projecting 3 feet 6 inches from the wall, cleared of all supports in five da\-s from the
time of filling in ; but this was with a good cement, gauged i part to 2 of aggregate, and in warm
weather, and the stair was strengthened with T iron.

The centring and framing for a flight of stairs should, where practicable, be independent of
other stairs above or below, so that they can be struck in due rotation. The wedges of the main
props should be gradually withdrawn. This tends to avoid the sudden jar which otherwise often
happens when the centring is too suddenly struck. The sudden removal of centring and the
inflexible nature of concrete are the cause of body cracks. The damage caused by the sudden jar
may not be seen at the time, but it will be eventually developed by the force of expansion, which
always finds out the weak spots.

Concrete and Iron. — Iron pipes, bars, and T pieces are sometimes used with concrete

494 Plnsferiiig — flai// and Decorative.

stairs where the steps arc long, or where landings have little support from walls. The)- help to
carr)- the dead weight until the mass is thoroughly set, and also ]3revent sudden deflection if the
centring is struck too soon. When iron pipes are used for steps, the\- should go right iiiti) the wall
chase. Iron T pieces are used for long landings. Care must be taken that, if iron is used, no part
should be left exposed. It must be embedded in the concrete to protect it from oxidisation and
the effects of fire. When iron girders, &c., are partly exposed, the}- should be painted. Iron bars
or pipes are occasionally used to strengthen the outer strings of spandrel stairs. The iron is laid in
the moist concrete near and along the string, having the ends projecting into the walls or landings.
Angle irons are often used for unsupported concrete angles. Iron jjipes, bars, or joists are used as
integral supports for landings and floors having unsupported ends.

The tensile strength of bar iron is materiall\- increased by twisting. A bar \ inch scjuare with
three twists per foot, or a bar \ inch square with five twists per foot, will gain about 50 per cent, in
tensile strength when embedded in concrete, and give a corresponding strength to the concrete. A
combination of iron and concrete is of special service where space is limited. For instance, if a beam
or landing requires a certain thickness to carry a given weight, and it is incon\enient or difficult to
obtain that thickness, the requisite degree of strength with a reduced thickness may be obtained by
the combination of both materials. This gives the combined iron and concrete a useful advantage
over stone. It is important to secure the full strength of the iron, and that none be lost or
neutralised. In order to obtain the full strength, the iron should be judicious!}- ])laced. Thus a
piece of iron surrounded b)- twenty times its sectional area of concrete would increase the weight-
sustaining power of the iron about twenty times, and concrete with one-twentieth its sectional area
of iron in the centre would ha\e its strength increased about tw-ice. If the same quantity of iron was
placed in several pieces, so as to throw as much tensile strain on the iron as possible, the strength
would be increased nearlj- four times. In order that none of the strength be lost or neutralised, the
iron should be placed near the lower surface ; if fixed higher, they are nearer the axis of neutral
stress, and are correspondingly less effective. The use of iron in concrete is invaluable for many
constructive purposes, but for general work, unless as a temporary aid and in a few exceptional cases,
it is unnecessary. For all other things being equal, the huge hoard of reserve strength in good
concrete is alone sufificient to sustain as great if not a greater weight than that sustained by natural
stone. No other artificial compound exceeds the strength of the natural substance, as does artificial
stone composed of Portland cement concrete.

Setting Concrete Soffits. — The soffits of stairs and landings, if neat cement has been used
on a waterproof centring, as already described, only require a little stopping and colouring, but for
work done on rough centring a setting coat has to be laid. This is usually done with neat Portland
cement, though it is frequently gauged with lime putt_\- to make it work more freely. The surface
should be well roughened and wetted, to give a kej- and obtain perfect cohesion. It requires great
care and time to make a good and true surface with Portland cement on a body of concrete,
especially if the concrete is dry, which is generally the case where there are .several flights of steps
in a staircase, and the setting of the soffits and landings are left to the last jjart of the work. I ha\e
obtained equally good results by using Parian or other white cements for setting the soffits of
staircases. When using white cements for this purpo.se, it is better to brush the concrete surface
with liquid cement before laying the gauged cement. The laying trowel should follow the brush, or
at least before the liquid cement dries in. This not only secures better cohesion, but tends to
prevent the .setting coat peeling w-hen trowelling it off. Soffits are sometimes set with gauged ])utt\-.
This is like putting a beggar on horseback, and the work is never satisfactory.

Concrete and Fibrous Plaster, 495

Fibrous Concrete. — As already mentioned, canvas and other fibrous materials may be
advantageously used with Portland cement for several purposes. Canvas forms a good ground for
a setting coat on concrete surfaces. It gives a uniform and strong key, pre\ents surface cracks
and the final coat from peeling. Coarse canvas cut to convenient sizes is used. It is laid on the
centring, and held in position with tacks, or with the same kind of cement as intended for the final
coat The canvas is then brushed with liquid cement, and then the concrete is laid while the canvas
is moist, so that the whole will form one compact body. When the centring is struck, the fibrous
concrete surface is roughened with a sharp and fine drag, so as to raise the fibre of the canvas, thus
giving a fine, regular, and strong kej-. This surface requires less material for the final coat than the
ordinary concrete surface. If tacks are used, the>- must be extracted before the final coat is laid, to
avoid discoloration. The rough concrete and the white surface coat may also be done in one
operation. The centring is made fair and smooth, and then oiled with chalk oil. The white cement
is gauged stiflT, and laid on the centring. Coarse canvas is then laid on and well brushed with liquid
cement. WTien this is firm (but not set), the surface is again brushed, and then the concrete is laid.
The concrete is deposited in Xxo or more layers. The first must not be too thick, taking care that it
is well rammed or pressed on the moist canvas surface without disturbing the white cement After
the centring is struck, any defects on the surface are made good. The surface may be then left
white, or painted, or polished as required.

Polished Soffits. — Soffits, landings, and strings of concrete stairs that are finished in white
cement may be polished. The material may be tinted, or left in its natural white or creamy colour.
Polished cement work is always bright, and has a lustre like marble. Being durable and easily
cleaned, it is more sanitary and cheaper than paint The polishing is done the same way as
described for " white work " in Chapter XV.

Concrete Stairc.vses .\xd Fibrous Plaster. — Fibrous plaster is well adapted for concrete
surfaces when an enriched finish is desirable. I have introduced this material for decorating the
soffits of steps and landings, also the strings of concrete stairs. By this method the soffits and
strings can be panelled, or enriched with medallions or foliage, as required. The soffits may also be
enriched with modelled work done in situ wnth some of the white cements, or with plaster and tow.
The strings may be decorated with hand-wrought gesso. In order to obtain a fixing or keying
substance that will receive naib or screws to sustain the fibrous plaster, a rough plan of the design,
or rather the fixing points, is set out on the inside of the centring before the concrete is laid. On
these plans, wood plugs, fillets, or concrete fixing blocks are laid, and held in position with nails,
plaster, or cement until the concrete is laid and set Care must be exercised when fixing the plugs
or fillets that the centring will leave freely without distiu-bing the plugs, &c. The use of fixing
blocks for this purpose is illustrated in Chapter XI. If the steps are cast and built, the plugs or
fixing blocks are cast with the steps. The principal staircase of the Tivoli, London, constructed by
my son, J. Millar, for the Patent Paving and Construction Company, is a good example of the
combination of concrete and fibrous plaster.

Dowel Holes. — Cutting dowel holes in concrete to receive iron or wood balusters is a slow
and tedious process. They are best formed by means of wood plugs, which are fixed before the
concrete is laid, or they may be driven in the concrete while soft If the balusters are to be fixed on
the treads, the plugs are driven into the rough concrete before it is set, lea\-ing them flush with the
line of tread, so that when the topping is laid they will not be in the way. Plugs are best fixed by
the aid of a wooden gauge. The gauge is made the same thickness as the topping, the length being
equal to the distance between the nosing mould and the riser board, and as wide as will admit of

496

P/(isfcriiig-

- PI a ill and Decorative.

plu<; holes and the plugs to be driven through. The plugs are made a little larger than the baluster
ends to allow for lead. The gauge is laid on the rough concrete, using the returned nosing mould
as a guide, and then driving the plugs flush with the top of the gauge. The gauge is then lifted up
and laid on the next step, and so on until the finish. This method is accurate, and saves measuring
and marking the position of each hole on every step. When balusters are fi.xed on the ends of the
steps, the plugs are fixed on the inside of the outer string. The plugs are generally left in until the
balusters are ready for fixing. A ready method for forming " lewis " holes or other undercut sinkings
in concrete is performed by casting wedge-shaped blocks of plaster of the required form and size,

and then laying them in the desired

Fig. I.

fig-

lr',r/.'^/yy/'^.'n

No. 197. — Sections of Steps.

]jositions while the concrete is soft.
When the concrete is set, the plaster
blocks can then be easilj- cut f>ut,
leaving the undercut sinking as
desired.

Summary ok Stairc.vsk.s con-
structed "IN SITU." — It will be seen
from the foregoing that the operations employed in the construction of concrete staircases formed
in situ are — (i) Setting out the stairs and landing; (2) fixing the wood framing; (3) gauging
the materials and filling in; (4) removing the framing; (5) cleaning up the treads, risers, and strings ;
(6) striking the soflfit centring and finishing the soffits ; (7) protecting and wetting the work until
set and hard.

Cast Steps. — Stairca.ses are also constructed with steps cast separately, and then built in, in
the same way as stone. Illustration No. 197 shows various sections of steps. Fig. i is a spandrel

Fig.

No. 198. — Treads and Risers.

No. 199.

The tread is grooved to afford a

step, which may be used for model dwellings, factories, &c
good footing and prevent dipping. The dotted line indicates a square seating or tail end of the
step, which is embedded in the wall. Fig. 2 is a square step. Fig. 3 is a step with a moulded and
returned nosing. Fig. 4 is a similar step, but having a moulded soffit. For cast work these steps must
have a square seating or tail end as indicated by the dotted lines on Fig. i, .so as to bond into the wall.
Treads and Risers. — Stairs between walls are sometimes formed with treads and risers. The
treads and risers are cast and built in as the construction of the work proceeds. Sometimes they are let
into chases, and pinned after the walls are built. Illustration No. 19S shows a section of treads and risers.

Concrete Floors. 497

Closed Outer Strings. — Staircases are sometimes finished with a close outer string, which
prevents dirt or wet falling into the well. Illustration Xo. 199 shows the section, Fig. i, and the
elevation. Fig. 2, of a moulded outer string. The dotted line at A indicates a dowel hole for the
balusters. Outer strings, whether plain or moulded, are much stronger when formed in situ. This
is best effected by fixing a reverse mould at each side, then filling in the space from the top. The
top is finished by hand and the aid of a template. The dowel holes are formed as already
described.

Concrete Floors. — It has already been mentioned that the Romans, in the time of Julius
Caesar, were in the habit of constructing their floors and roofs, as well as their walls, of concrete.
According to an article in Arcliaologia, the cementitious agent was pozzolana. This substance, when
mixed with lime, forms a natural hydraulic cement. The lime was obtained by burning " travers-
tine." The aggregate usually consisted of broken tufa for walls, of broken lava for foundations
where great strength was required, and of broken pumice where lightness was essential. The floors
were generally constructed of large slabs of concrete, supported on sleeper brick walls. The upper
surface was finished with a layer of finer concrete and mo.saic. The roofs were made flat, resting
on brick pillars. The first known English patent for fireproof construction was obtained by one
Dekins Bull in 1633 ; but as at that period patentees were not compelled to disclose what their
patents coxered, no description of the materials and methods can be given. Up to the middle of
the eighteenth century fireproof floors usually consisted of brick arches, but owing to their great
weight and cost, were seldom used. But towards the close of that century cast-iron girders and
segmental brick arches were gradually coming into u.se where strength was essential. Up to a
century ago plaster was largely employed as a floor material. In 1778 Earl Stanhope invented
pugging for rendering wooden floors fireproof By this process fillets were nailed to the joists at
about one-third of the height. Laths were laid on the fillets, and plastered above and below
with a coat of lime and chopped hay. The under sides of the joists were then lathed and
plastered in the usual way to form the ceiling. About the earl\- part of the present century
wrought-iron joists were substituted for cast-iron girders. Fox & Barrett's floor, designed about
1830, was the first in which an attempt was made to protect the exposed faces of the iron joist with
a fire-resisting material. Hornblower's floor is one of the earliest for resisting the effects of fire.
Iron, bricks, and plaster are chiefly used in the French and American systems. Among the
man\- modern systems now in use in England may be mentioned those of Dennet, Wilkinson,
Homan & Rodgers, Doulton, Peto, Mark Fawcett, Potter, and the author, &c. For the sake of
simplicity and reference, concrete floors may be divided into three kinds: — i. "Joist floors," in
which the concrete is laid solid between the joists. 2. " Tubular floors " formed with fireclay
tubes or hollow lintels placed between the joists and covered with concrete. 3. " Slab floors "
formed in one piece or slab. Portland cement concrete laid in situ on and between iron joists is
extensively used for fire-resisting structures. Cast concrete is used for some parts of tubular
floors. For my patent PhcEnix fireproof floors and partitions, concrete alone is used. Cast
concrete blocks are used for the ceiling surface, and as a support for the rough concrete floor
surface. The blocks are hollow, and have male and female dovetails on the sides. The ceiling
surface of the floors and the outer surfaces of the partitions are finished with a thin .setting coat of
gauged putty or Parian. The chief objects of fireproof floors are to render each floor capable of
resisting the effects of fire, so that fire cannot be communicated from one floor to another, and by
making the roof fireproof, to prevent fire from spreading from one compartment to another ; to
gain additional strength, so as to avoid as far as possible lateral thrust on the walls, and to secure

49'"^ Plastering — Plain and Decorative.

the buildiiiy from the attacks and effects of both dr\^ rot and damp. There have been about a
hundred patents for fireproof floors during the last generation, of which about five or six survive.*

ri,.-\STER Floors. — Plaster concrete, that is, plaster and broken bricks, or similar aggregates,
also neat plaster, were at one time used largelj- for the formation of floors. The use of plaster
floors was common in some districts, and up to a century ago the rough plaster, known as " floor
plaster," was in general use in the midland counties, or where gypsum was found in abundance.
Plaster floors were rarelj- used on the ground le\el, because they could not resist moisture, which
caused them to become soft and retain the damp. Thc\- were principally u.sed for upjoer floors.
The gauged plaster was laid upon reeds similar to those used for lathing before the modern
plasterer's lath came in, which were so plentifully obtained from the swamps and undrained lands
in the Lincolnshire and Cambridgeshire fens. These reeds were spread u])on the tops of the
joists, and o\er them was laid straw to keep the soft plaster from percolating through the reed.s.
The floors were about 3 inches thick, floated fair, and finished the following day. Wood strips
were placed around the walls, and drawn out when the ])laster began to set, to allow for the
expansion of the plaster. The materials being so liglit, the timbers were less in size and number
than those now in u.se. The joists were in some instances onl\- 3^ inches by 2i inches, fi.xed wide
apart, and sujjported by small beams about 4! inches by 3i inches. The under sides between the
joists were made fair by plastering the reeds, but in the better class of work the joists were covered
with reeds, and held in position with oak laths, and plastered. Ikillock's blood was used to harden
the floors after the)' were dr)'. In some instances they were coated with linseed oil to increase
their hardness. Their use is now practically superseded by Portland cement concrete. Dennet
& Inglis' well-known fireproof floors are chiefly composed of coarse plaster and broken bricks.

Joi.sT CONCRETi: Floors. — For this form of floor the concrete is laid between, over, and
under the iron joists. Beyond the supervision c)f the fixing of the centring and the gauging of the
materials, little skilled labour is required. The rough concrete is laid between and partly under
the iron joists, which are fixed from 3 feet to 5 feet apart, according to the s])an and strength of the
joists. The centring is supported, or rather hung, by the aid of timber laid across the joists, and
secured by bolts. The materials are generally Portland cement and gravel, coke-breeze, clinkers,
and broken bricks, gauged in the proportion of i part of matrix to 5 of aggregate. Gravel, owing
to its weight and roundness, is not a desirable aggregate. Sand equal to one-third of the bulk
should alwa\-s be added. Coke-breeze is weak, light, and elastic, but combustible and pfirous. A
mixture of gravel and breeze in equal proportions is better than either alone. The proportion of
cement varies according to the span and class of aggregate. All other things being equal, the
strength of concrete is influenced \>y the strength of the aggregate, so that it would take a greater
proportion of cement to make coke-breeze concrete equal in strength to a concrete made with hard
aggregate, such as granite, slag, or brick. The ujjjjer surface of this class of floor ma}- be finished
with wood, tiies, or fine concrete, as required. Joist concrete floors ha\e been largel}- used. This
is principally owing to their suppo.sed cheapness ; but it is more than probable that, in the event of
fire, the\- would be dear in the end, because the lower part of the flanges are barely protected from
the effects of fire, as the concrete, being thin at these parts, and also on a comparati\el)- smooth
surface, would soon crack or scale off, and lea\e the flanges of the joists exposed to the raxages of
fire. They are also more or less conductors of sound. Caminus concrete cement is an excellent
material for the construction of fireproof ceilings and partitions.

* Those desirous of further information on this subject are referred to a very practical and useful work, entitled
" Concrete, its Uses in Building," by T. Potter. Published by B. T. Batsford, 94 High Holborn, London.

Concrete Floors ami Fibrous Plaster Ceilings. 499

Cami.nus Conxrete Cement.— This material is specially designed to produce a hard and
practically indestructible concrete for the construction of fireproof floors and walls. It is manu-
factured from a waste product, and all inflammable material such as coke-breeze being entirely
dispensed with, the concrete is thoroughly fire-resisting. It is lighter and much cheaper than
Portland cement concrete, and is perfectly free from e.xpansion and contraction whilst setting. It
can be manufactured to set in a few hours, so that the centres can be struck the day after the floor
is laid. It can be supplied in a ready aggregated condition, so that the bags may be hoisted direct
to the floor where the concrete is being laid, and gauged on the floor, thus saving a great amount of
waste, and also labour in handling, mixing, and laying.

Concrete Floors and Coffered Ceilings. — A method was patented by E. Ransom, in
America, for decreasing quantity of material and yet obtaining equal strength in floors. The floor is
divided b)^ a series of beams at right angles to each other, so as to form a series of coffers in the ceiling.
For instance, for a floor 12 inches thick, the floor proper would be about 4 inches thick, and the
beams about 3 inches thick and 8 inches deep — a rod of twisted iron being placed in the centre of
the thickness, and near the lower surface of the beams. The beams are generally about 2 feet 6
inches from centre to centre. The method of construction is as follows : — First form a platform or
centring ; on this a series of core boxes 2 feet 3 inches is placed, 3 inches apart, so as to form a
3-inch beam. The core boxes must be tapered and their upper edges rounded, .so that they will
draw when the centring is struck. The size of the core boxes may be altered to suit the size and
requirements of the floor. With regard to the iron bars, the inventor says : " It is of vital import-
ance for the strength of the structure that the iron bars be placed no higher in the beam than
calculated for ; that the longitudinal centre of these bars should be at the lowest point ; and it is
advisable that the bars curve upwards slightly and uniform!)- each way from the centre to the ends
so that the ends are from i to 2 inches higher than the centres. By preparing the concrete bed on
a corresponding cur\e, the natural sag of the bar, as it is being handled to its place, gives all the
requisite facility to accomplish this purpose. No crooked or irregularly twisted iron must be used,
otherwise, when the strain comes upon it, it will perforce straighten and lengthen out, and weaken
the structure in so doing. After placing the iron, the rest of the concrete is tamped in place, and
the whole made to form a monolithic block. It is of vital importance that no stop be made in
the placing of the concrete from the time the beam is begun until the thickness of the beam is in
place and a 'thorough joint' is made. The web and the thickness must be one solid piece of
homogeneous concrete."

Combined Concrete Floors and Panelled Ceilixcs. — A combined floor and panelled
ceiling may also be formed in concrete. This is executed as follows : — First form a level platform or
centring, and on this fix the reverse plaster mould, run and mitred, according to the design of the
ceiling. The intervening panels are then made up with framing, and the concrete filled in in the usual
waj-, and when set the centring and the reverse mould are removed, and the ceiling cleared off. If
desired, a finely finished and smooth white surface may be obtained by coating the surface of the
moulds and panels with firmly gauged Parian, or other white cement, until about 2 inch thick : and
when this is firm i but not set,\ the rough concrete is deposited in laj-ers and tamped to consolidate
the concrete, and unite it with the white cement. The surface ma\- also be finished with fibrous
concrete. The method of doing this, also for carrjing out the above white cement process, is
described in " Fibrous Concrete," page 495.

Concrete and Wood. — Concrete floors finished with flooring boards require special care to
prevent damp or dr)- rot. There are various methods in use for fixing and keeping the flooring

500 Plastering — Plain and Decorative.

boards from contact with the rough concrete, one ua)- being to fix wood fillets to the iron joists b>'
means of wedges or clamps. Another way is to embed wood fillets or fixing blocks in the rough
concrete, leaving them i^rojecting above the level of the iron joists, to give a bearing and fixing
points to the flooring boards ; or fine coke-brccze, concrete or plaster screeds, ma>- be laid at intervals
on the rough concrete, on to which the boards are nailed. Fixing blocks, concrete or plaster
screeds, are preferable to wood fillets, as they do not shrink or rot, and will better resist fire. All
these methods leave intervening spaces between the concrete and the boards, and unless thoroughly
ventilated, the\- harbour \ermin, dirt, and stagnant air. Unless the wood is thoroughly seasoned,
and the boards grooved and tongued, dust and effluvia will find egress through the joints. A
portion of dust and water when sweeping and washing the floors also finds an ingress through the
joists; and as the concrete will not absorb the water, or allow the dust to escape, they accumulate
and become unseen dangers. These insanitary e\ils may be obviated, or at least reduced to a
minimum, by laying the boards direct on the concrete. This not only forms a solid floor with no
interspaces, but admits of a thin board being used with as much if not greater advantage than a
thick board. There is no uneven springing between the joists, w hich causes friction and opening of
the joints, and the whole thickness is available for wear. There is also less total depth of floor,
consequentlj- less height of building and general cost. Another important ad\antage of a solid
floor is, that it will resist fire better than one with hollow spaces. It is here that the sponginess
and elasticit)- of coke-breeze concrete as a top la_\er is of special service, and where it inay be
utilised with advantage. Owing to its being able to receive and retain nails, the boards can be
nailed at an)- desired place. Wood blocks for parquet floors can also be bedded or screwed on the
concrete surface. Flooring boards will lie even and solid on this surface, and if a thin layer of felt
or slag-wool be spread on the concrete before the boards arc laid, a firm and noiseless floor is
obtained. Slag-wool is an imperishable non-conductor of heat, cold, and sound, and it will not
harbour \ermin. If the work is in a humid climate, the coke-breeze surface when dry should be
coated with a solution of tar and pitch, to prevent atmospheric moisture being absorbed by the
porous coke-breeze.

CONXRETE Drying. — To prevent dry rot it is of the utmost importance that the concrete should
be thoroughl)- free from moisture before the flooring boards are laid and fixed. The drying of concrete
is a question of time, which depends upon the amount of water used for gauging, the thickness, and the
temperature. It may take from three da}-s to three weeks or even three months. The drying can
be accelerated bj- directing currents of hot air on to the lower surface, or by laj'ing some absorbent
material, such as drj- sawdust or brick dust, on the upper surface. As soon as the surface moisture
is absorbed, or the drj- material has no further absorbent power, it should be removed to alknv the
mass to be air dried. Another way is to la)- the floor in two coats, and to allow one coat to dry
before the other is laid. For instance, if the floor is to be 6 inches thick, the first coat is laid with
rough but strong concrete, the aggregate being the best available ; but taking gravel and coke-
breeze to be the most plentiful, it will be best to assimilate and combine the good qualities of each
to equalise their defects by mi.xing them in equal proportions. If brick is plentiful, and broken to
properly graduated sizes, it will give better results than the gra\el and breeze. The mixed
aggregate is gauged 5 parts to i of cement, and laid \\ inches thick, and gently but firmly beaten
in situ, the surface being left rough to give a key for the second coat. The second coat is not laid
until the first is dry, and consists of i part cement to 5 of sifted and damped coke-breeze, gauged
stiff, and laid \\ inches thick, beaten in situ, ruled level, and any ridges being laid fair with a long
hand-float. The moisture of the second coat, by reason of the density of the first coat, will only be

Concrete Slab Floors. 5oi

absorbed to a small degree, while the greater portion will be taken up bj- the atmosphere, and
enable the combined coats to dry sooner than if laid in one. The first coat should be laid as soon
as the roof is on, so as to give all possible time for it to dry, and the second coat to be laid and
dried before the flooring is laid. When coke-breeze is not available for the second coat, use soft
brick, broken to pass through a VV-'^ch sieve. The method of laying floors in two coats is only
given as an alternative plan, and as an example of a process u.sed in .some parts. Greater strength
as a whole, and more perfect cohesion between the two coats, is obtained by laying the second coat
as soon as the first is laid, or at least while it is green.

Concrete Sl.\B Floors. — The term slab floor is applied to a concrete floor formed in situ,
and in one piece or slab. It must not be confounded with slab pavements, which are constructed
with a number of small cast slabs. Slab floors are usualh- made without exterior iron supports,
but in a few instances iron T pieces or bars have been used as internal sujjports. Bearing in
mind the lasting properties of the old Roman slab floors, and the enormous strength of the modern
examples at home, which are unsupported by iron, and are practically indestructible, it seems
strange that the)- are not in more general use, and that for some inexplicable reason preference is
given to shrinking, rotting, and combustible floors, compo.sed of foreign iron and timber instead of
British work and material, which if a little dearer at first, is infinitely superior, and vastly cheaper
in the long run. The great sanitary advantages and fire and damp resisting powers of concrete
slab floors are the highest known. The construction of slab floors is simple, and similar in many
respects to that already described for stair landings and ordinary concrete and joist floors. There
are several methods of supporting the floors, the first and most common being to leave a sand
course, or to cut a horizontal chase in the walls to receive the ends of the floors. The second is
to la\' the floors when the walls are floor high, and build the higher walls on it when set. This
method, while making sound work, is not alwaj-s practicable or convenient, owing to the dela\- in
building while waiting for the floors to set. The third method is to build corbelled ledges in the
walls, so as to carry the floors. The centring for slab floors should be perfectly rigid, water-tight,
and slightly cambered to\\ards the ceiling centre. This camber gives more strength to the floor,
and lessens liability to crack when removing the centring. If joists are not used, the centring is
supported on wall boards and centre struts. Another wa\- which gives great additional strength is
to form the centring level, but having all the edges at the wall rounded off, so as to form the floor
like an inxerted sink or tra\-. The horizontal chases in this case should be made wider than the
thickness of the floor to allow for a thickness of rim. The extra width of chase, which may
be one or two bricks thick, according to the width of span, is made below the centring or line of
ceiling, the angles being cov-ed b}- rounding the edges of centring. The coved rim gives greater
strength with a less thickness of floor. The cove may be left plain, or used as a cove for a
plaster cornice, or roughened and used as a bracket for the same purpose. The expansion of
concrete floors ha\ing large areas, or where hot cement has been used, has been known to disturb
the walls, causing cracks and displacement of brick and stone work. This ma\- be prevented by
isolating the floor ends from the walls. This is done by forming expansion partitions or linings in
the chases, the linings being composed of slag, felt, or wood shavings, straw, reeds, or other
compressible material. The chase should be sufficienti)- deep to allow for a compressible
lining about li inches thick, and a fair bed for the slab floor. Care must be taken to leave
a few half bricks solid at intervals, say from 3 to 4 feet apart, to support the upper walls until
the floor is set. Compressible linings may be used for floors supported on corbelled ledges ;
and when the expansion, and in many cases subsequent contraction, has finallj- finished, the

S02 Plastering — Plain and Decorative.

linings can be taken out, and tlie vacant space filled uj) w ith fine concrete, or utilised as a t^round
ke>- for cement skirtings. If girder or iron posts are isolated from the walls by means of compres-
sible linings, the effects of expansion and sound are limited. In some instances a judicious use of
iron may be made. For instance, large areas may be divided with three or four rolled iron joists,
so as to form shorter spans or smaller bays. Joists tend to bind the walls together, and to serve
as scaffold bearings for building tlic upper i)arts of walls. They may also be used for hanging the
centring on instead of strutting, or as aids to the strutting. Joists may also be used as integral
supports at unsupported ends of concrete floors. They should be so fixed that the lower flanges
are not less than i inch above the lower surface of the concrete. The whole strength of iron is
brought more fully into use b\- fixing it near the lower surface. If fixed near the centre, or at the
axis of neutral stress, a corresponding part of the strength is comparatively of little value.

Construction of Slah Floors. — Portland cement as a matrix is indispen.sablc. The
unequal nature of gravel and coke-breeze render them unfit and unsafe aggregates for this class
of work. Broken brick being cheap, and obtainable in most districts, affords a ready' aggregate,
and may be used with safety and success. In ordinary cases of concrete construction, the whole
thickness is usually made with one rate of gauge ; but for slab floors covering large areas, and
unsupported by iron or other sujjports, exceptional strength is required. Stronger results are
obtained by making up the whole thickness with different rates of gauge. Taking the usual gauge
for floors as from 4 to 5 parts of aggregate to i of cement, and used for the whole thickness, it gives
an unequal strength, a part of which is comparatively of little use, especially at the neutral axis ; but
if the cement is divided so as to form an ordinary coat in the centre, and stronger coats at the
upper and lower surfaces at the ]3oints of greatest strain, the upper being compressive and the lower
tensive, a better and more accurate arrangement of strength and allowance for disposition of strains
is obtained. The additional strength at the proper places is obtained not by the use of additional
cement, but by the method of construction, which enables the same quantity of cement as gauged
for the usual rate for forming the whole thickness in one coat to be used more profitabl)'. Take the
section of an iron joist as an example ; this gives divided yet united strengths, which sounds
paradoxical, but is true. The flanges sustain the greatest strains, and the web comparatively little.
With concrete, the strong coats at the upper and lower surfaces represent the flanges, and the
ordinary coat the web. As already stated, the increased and profitable distribution of strength is
obtained by the method of construction. For instance, take a slab floor 20 feet by 14 feet and
12 inches thick, without iron joists or other supports, and intended to carry a safe load of 2 J cwt. per
superficial foot, in addition to its own weight of say i cwt. per square foot. This floor is laid in
three coats, the first composed of i part cement and 2 of fine broken bricks gauged stiff, and laid
2 inches thick ; the second composed of i part cement and 6 of coarse broken bricks gauged stiff,
and laid and rammed 8 inches thick ; and the third composed of i part cement and 2 of fine broken
bricks gauged stiff, and laid 2 inches thick. If the upper surface is intended for hard frictional
wear, a slight difference is made in the gauge and materials. The first coat is composed of 2 [)arts
of cement and 5 of fine broken bricks gauged stiff, and laid 2 inches thick ; the second of i part
cement and 6 of coarse broken bricks gauged stiff, and laid and rammed till 8 inches thick ; and
the third coat composed of i part cement and 2 of fine crushed slag or granite. It will be .seen
that this constructive method gives the desired positions of strength, and the total quantity of
cement in the united gauges is i part to 4 and up to 5 parts of aggregate. The fine broken bricks
should be passed through a J-inch sieve, and the coarse through a 2-inch screen, taking care
that the latter contains a greater quantity of the smaller pieces than of the larger. It must be clearly

Concrete Roofs.

■i^i

understood that the second coat must be laid before the first is set, also that the third is laid before
the second is set, so as to ensure perfect cohesion between each coat, and the absolute homogeneity
of the uhole mass.

Hollow Floors. — Greater lightness in concrete floors is obtained by the use of concrete
tubes. If the tubes are placed apart and in the centre of the floor thickness, a hollow homogeneous
concrete slab is formed. The \ertical divisions between the tubes connect the upper and lower
coats, as with the web of a joist connecting the upper and lower flanges. The method of con-
struction is simple and expeditious. For example, for a slab floor ID inches thick, first lay a coat
2 inches thick of the stronger and finer concrete, as described for the 1 2-inch slab floor, and when
this is firm lay 5 or 6 inch tubes from wall to wall. Bed the sides with rough concrete, and la>'
another row of tubes parallel with the first row, and about 2 inches apart, and so on until the floor
area is covered ; then make up interspaces with rough concrete till level with the upper surfaces
of the tubes, and then cover this with a coat of fine concrete 2 inches thick. Concrete tubes or
common earthenware drain pipes may be used. Half-circle pipes, laid on their side edges, may
be used to save concrete and weight in joist floors, &c.

CoN'CRETE Roofs. — Concrete roofs require special care to render them watertight. Subsidence
in the brickwork of new buildings is often the cause of cracks on concrete roofs. The roof should
have a good camber, to give greater strength and allow for the fall of water to the outer edges.
The rough coat should be laid and well consolidated b\- ramming or beating, and then left for
seven days (the longer the better) before the topping is added. The upper coat should be strongly
gauged with fine aggregate as in " Eureka." If possible, the topping should be laid in one piece.
If the area is too large to be laid and finished in one piece the joints of the bays should overlap.
This is done b\^ rebating the screed rules, so as to allow one-half of topping thickness to go under
a part of the rule, and form an underlap or ledge about i inch wide, and when the adjoining bay
is laid an overlapped but level joint is the result. Roofs exposed to the sun's heat should be
kept damp for several days after being laid, as joints are affected by the heat as well as by deflection
of centring or subsidence of walls. Compressible linings or wood strips should be used round the
walls to counteract any expansion. All concrete roofs should have a cement skirting 6 inches high
and I inch thick well kejed into the walls. If linings are not u.sed when the topping is laid, the
topping should be turned up on the walls, so as to form a rim, to prevent water getting between
the roof and the walls. Greater heat and damp resisting powers are obtained by laying the upper
surface with A inch thick coat of special concrete, composed of i part of Portland cement, \ part of
slaked lime, and I part of firebrick dust. This should be consolidated with a hand-float, and
finished fine and close with a trowel.

Notes ox Con'CRETE.— When calculating the strength of floors, stairs, &c., the following facts
should be borne in mind. Portland cement when new is too hot, sets more rapidl}-, and expands
more than old cement. The finest ground cement is the best and strongest. The time in setting,
and in which the maximum strength is attained, varies according to the age of the cement, the
quantit}- of water used, and the mode of gauging and the mean atmospheric temperature. The
maximum strength of a briquette of mature cement is maintained, while one of new cement "goes
back." A briquette of matured cement will stand a tension strain of 550 lbs. per square inch, and
a crushing weight of 6,000 lbs. per square inch. A briquette of neat cement is more brittle than
one of concrete. Briquettes mature more rapidh- than thick slab floors. The adhesive strength of
Portland cement is about 85 lbs. per square inch. The adhesive strength increases more rapidl>-
than the cohesive. A mass with a surface large in proportion to its volume sets more rapidlj- than

S04

Plastering — Plain and Decorative.

a mass with a small area in proportion to its \olume. Masses subject to pressure set more rajjidl}'
and attain greater hardness than masses not so pressed. The average compressive strength of
concrete is about eight times its tension strL-ngth. The proportion of compressional and tcnsional
strength varies according to the quality and quantity of the aggregate. The strength of concrete
depends greatly on the proportion of the matrix and aggregate, also on the strength of the latter.
As regards bricks, it must be remembered that there is a wide difference between the tensile
strength of hard well-burnt bricks and soft stocks. No bricks are so strong as cement, the best
kinds being about one-fourth the strength of neat cement. Taking the gauge as i part of cement
to 4 of broken brick, the strength of the concrete will be about two-fifths of neat cement, but for safe
and practical calculations it will be best to take the strength as one-fourth of neat cement. Square
slabs are stronger than rectangular slabs. Slab floors being homogeneous throughout, the whole
weight is a dead weight, and consequently there is no thrust on the walls. With regard to the live
load or weight which floors should be constructed to carry, some difference of opinion exists. Hurst
says that for dwellings \\ cwt., public buildings li cvvt., and warehouses and factories 2\ cwt. are
safe calculations. Others assert that for domestic buildings i cwt. per foot would be ample for all
contingencies. An American authorit)^ states 40 lbs. is sufficient for ordinary purposes. The
following table shows the results of tests of slab floors made without iron, made by Colonel Seddon,
R.E., in 1874. The slabs were supported all round, and uniformly loaded with bricks.

Table XVI. — Tests of Slab Floors.

No.

Length

between

Supports,

leet.

IJreadth

between

Supports,

feet.

Thickness,
feet.

Age in Days.

Breaking

Weight, in

cwt. per

sq. ft.

Weight of

Sl.-ib,
in cwt. per

sq. ft.

Total P.reakint;

Weight,

in cwt. per

sq. ft.

14.5

6.75

•5

-54

3-54

2.76

3-30

))

»»

))

S.S8*

9.42*

13-5

1.07

1.61

>»

6-75

2.51

3-05

))

»>

2.S4

3.38

Cast (Concrete. — Innumerable patents have been obtained for a combination of materials,
also moulds for the construction of artificial stone. Among the many that may be mentioned is
Mr Ranger's system. He obtained a patent in 1832 for artificial stone formed with a lime concrete.
The aggregate consisted of shingle, broken flints, masons' chippings, &c. The inventor stated that
the best results were obtained by using 30 lbs. of an aggregate of a siliceous or other hard nature,

* This cracked under a load of 6A cwt. per square foot, Ijut did not break under the load of S.SS cwt. per square
foot, which was the greatest load available for putting on the slab. It is proljable that similar tests with slabs fixed
at the edges would show an increase of strength of 25 per cent, for No. 4 slab, which is nearly square, and 30 per
cent, for the remaining slabs. The slabs Nos. i, 2, 3, and 4 were composed of i part of Portland cement and 4 parts
of broken brick (passed through a i-inch mesh) ; the concrete was thoroughly rammed, and the slabs covered with
water for seven days. Nos. 5 and 6 slabs were composed of i part of Portland cement, \ of a part of sand, and 3 parts
of broken brick. These tests are invaluable, inasmuch that they were accurately made, and that no vested interests
were concerned. Similar tests made at the present time with the improved quality of Portland cement as now made
would yield much higher results.

Concrete Dressings.

505

3 lbs. powdered lime, and 18 oz. boiling water. No more of the materials were gauged at the time
than were sufficient to fill one mould, as the boiling water caused the concrete to .set very rapidly.
The College of Surgeons in Lincoln's Inn Fields, some houses in Pall Mall, and other structures,
ha\e been erected with " Ranger's artificial stone." The material after fifty years' exposure is still
sound, and shows no sign of decay. No artificial stone equals, far less excels, the strength and
durability, sharpness, and evenness of Portland cement concrete. This form of artificial stone is
now e.xtensi\el\- used as a substitute for natural stone, for window heads, string courses, sills,
columns, copings, keystones, and man)- other architectural, constructi\e, and decorative features.
Figures, animals, bas-reliefs, ca]jitals, panels, can be made in fine concrete with all the relief,-
undercut, and fine detail which distinguishes high-class from inferior work. I ha\e produced
replicas of some of Eglinton's beautiful shields and figures with all their minute details, also copies
of marble figures in fine concrete. Some of these were cast in plaster piece moulds, and others in gela-
tine moulds. Cast work has the advantage over in situ work, that anj- defect can be detected previous
to fixing. The methods of moulding and casting various works are given in the following pages.

Concrete Dressings. — Architectural works, especially large or plain parts, are generally
cast in wood moulds. If there are ornamental
parts in the blocks, a combination of wood and
plaster, and sometimes gelatine, is used for the
moulds : wood for the main or plain parts, plaster
for circular or moulded parts, and gelatine for
undercut parts. The plaster or gelatine, as the
case may be, is screwed on or let into rebated parts
of the wood. Ornamental parts are sometimes
cast separately, and then fixed on the main cast.
They may also be cast separately and laid into the
main mould Tface inwards), and the whole is cast
together in a somewhat similar wa\- to that
described for " bedded enrichments " in fibrous
plaster cornices.

Considerable skill and ingenuit}- have been displa\-ed in the construction of wood moulds for
casting concrete blocks for architectural purposes. Many methods have been employed for fixing
the sides and ends together, and also to the bottom of the mould, leaving one or more parts unfixed
to facilitate the release of the cast. The primitive method is to fix the various parts of the mould
with screws. This is a slow and unreliable proces^, as the continual screwing and unscrewing for
each cast soon wears the screw-holes, and the sides become loose and out of square, causing the
casts to get out of their true form. Hinges, also hooks and eyes, have been used for the same
purpose, but they are liable to the same defects as the screws when subjected to long use.

Thumbscrews to fit into iron sockets are also used, but thc\- are too expensive for ordinary
work, and are unsuitable for small moulds. One of the most simple and reliable methods is the
" wedge mould," invented by Mr G. M. Ja>-, architect. It is easily made, and expeditious in work-
ing. Even after long and constant use, the casts are always accurate in form and size. The
wedges and the rebated ends allow the various parts to be correctK" fixed and held in position.
Illustration No. 200 shows the method of construction. The various parts are named, and
the sketch is self-explanatory. When the moulds are extra deep, it is necessarj- to make two or
more sets of tenons and wedges at each angle. When there are a large number of casts required,

No. 200. — Wedge Mould for Casting Blocks, Moulded
Lintels, &c.

So6

Plastering — Plain and Decorative.

Fig. I.

Fig. 2.

I-;

the mould ends are strengthened b)- binding the projecting ends witli hoop iron. This method has
been adopted for casting about 3,000 cubic feet of moulded work for mansions at West Brighton,
designed b\- Mr Jay. Illustration No. 201 .shows two useful kinds of moulds. Fig. i is a
simple form of mould adapted for plain blocks, caps, lintels, &c. .\, A are the sides, which are
grooved into the ends H, B, and held together by the bolts and nuts C, C, two on each side.
The bolts ma\- be about iJ inch diameter, with a good-sized square-head at one end, and a
washer and nut at the other. This, having no bottom, is termed a bolted frame mould. It should
be laid on a bench or moulding board before the cast is filled in. Fig. 2 is a section of a combined

wood and plaster mould on the wedge prin-
ciple, adapted for casting a string course
moulding. .\ is a moulding board, li inches
thick, formed with two or more boards ; a is
one of two or more cross ledges, i inch thick,
on which .\, the ground, is nailed. B is a width
board, i inch thick, which is nailed on to .\.

No. 201.-F1G. i.-BoLT Moi-Lo FOR CASTING BLOCKS, &c. "T^is givcs a poiut of resistaucc to the plaster

Fig. 2.— Section FOR CoMBi.vEi) Wood AND Plaster piece C and the side board G. D is a side

MOULD FOR Casting Label AND STRI.NG MOULD- ^ j ^,^ ^^.j^j^j^ p j^ screwed. E forms the

INGS, &C.

sloping part of the weathering. F is one of
two or more vertical wedges which hold D E in position. The sockets for the wedges F are made
between the cross ledges, so that the wedge will project below the ground A. This allows the
wedges to be more easily driven out when the cast is set. G is the back or plain side board. H is
a fillet, li inches square, screwed on to the ground A. I and j are two folding wedges, or, in other
words, wedges driven in opposite directions. These hold G in position. Two or more of these
folding wedges are required, according to the length of the mould. The same remarks apply to the
vertical wedges F. The latter form of wedge is only given as an alternati\e. The end pieces are
held in position by dropping them into grooves in a similar way as shown in the previous figure,

with the exception that the grooves are
•■''g- '■ Fig- 2. cut in the sides instead of the ends. K is

a gauge rule which is used for ruling the
upper surface of the cast fair. This may
also be done by working a straight-edge
longitudinally. The dotted line at L, the
concrete, indicates the wall line. The
level part of the weathering up to this
line, or if splayed from the outer member
of this line, must be finished smooth to
allow the water to run freely off. When the cast is set, the wedges are withdrawn, and the sides
and ends released. The cast is then turned over on its back end or top side on a board, and then
the plaster piece and the wood ground is taken off. If the cast is green, it should be turned
over on old sacks or wet sawdust, so as to protect the arrises, and a\oid fractures.

Illustration No. 202 shows a method commonly adopted for constructing moulds for sills
and copings. Fig. i is the section of a mould for a window sill. A is the moulding board, made
with two or more pieces, each \\ inches thick ; a is one of two or more cross ledges, made with
I -inch stuff, on which A is nailed. B is the width board, made of |-inch stuff, nailed on to A.

P7^

No. 202. — Fig. i.-
FiG. 2.-

-Section of Mould for Casting Sills.
-Section of Mould for Casting Coping.

Moulds for Casting Concrete. S07

C is a block, \\ inches thick, which is nailed on to B. These blocks are placed about a foot apart,
or so that they will carry the lining D, i inch thick. A groove for an iron tongue E is made in B,
and a piece of thick hoop iron or iron bar is placed loosely in the groove before the cast is filled in.
F is a fixed side, i^ inches thick. G is a fillet, li inches square, nailed on to F, and screwed on
to moulding board A. H is a loose side, i^ inches thick, on which the fillet I is nailed. J is one of
two or more clips, which turn on a screw, and are used to hold the loose side H in position. These
clips are made and used in the same wa\- as described for fibrous slabs. As compared with wedges,
clips are always in position ready for use, are not liable to be mislaid, and when the fillets are
fixed on to the side pieces, the clips keep the sides from rising as well as expanding. K is a
throating, or water groove, which is formed in the concrete L, with a rule having a rounded edge.
Two blocks, dished at the inner ends, must be fixed one at each end of the mould, so as to form a
stool or bed for the superstructure. The position and form of the groove is obtained from sinkings
cut in the end pieces of the mould. The end pieces are held in position by grooves cut in the side
pieces in a similar way, as already described, with the exception that the grooves are cut in the
side pieces instead of the end pieces. When setting out the mould, an extra length must be
allowed for the side pieces for the grooves. A part of the upper surface of the cast (being the part
which projects beyond the line of wall) must be finished fair by hand at the same time as forming
the water groove. This must be done while the cast is green. When the cast is released from the
mould, the iron tongue will be found firml)- embedded in the concrete. Fig. 2 is a section of a
wood mould adapted for casting wall copings. A is the ground of a moulding board, which may be
made of i ^-inch stuff, and in two or more widths ; a is one of two or more cross ledges, i inch
thick, on which A is fixed. B, B are blocks about i\ inches thick, placed about i foot apart. C, C are
linings, i inch thick, nailed to B, B. D is a fixed side, i^ inches thick. E is a fillet, li inches square,
fixed to D, and then screwed on to A. F is a loose side, i^ inches thick, on which is nailed the
fillet G, ij inches square. This strengthens the side, and affords the fixing point for the clip H.
The water grooves I, I, and the hollowed [lart in the middle of the concrete J (made to save
materials in weight) are worked from the end pieces of the mould, which are let into the grooves,
as described in the previous diagram, if the moulds are deep, wood or iron clamps may be fixed
across the sides to keep them in position, as shown by K. The moulding boards in this and the
previous figures, if strongly made, can be used for a variety of similar purposes. When introducing
cast instead of run moulded work, I used iron and zinc plates to strengthen and make more
durable plain surfaces on wood moulds ; but owing to the expense and trouble in fixing the
plates to the woodwork, they were abandoned, and by using a better class of wood, and indurating
the surface of the mould with hot paraffin wax, sharp and clean casts were more cheaply produced.
Cast-iron moulds ma\- be used where there is a large number of casts required. They may also
be advantageously used for stock designs, such as plain moulded balusters. Wood moulds are
rendered more durable and impervious to wet by brushing them with hot paraffin wax, and then
forcing it into the wood by ironing with a hot iron. The use of paraffin wax and oil has already
been described.

There are numerous creditable examples of cast constructional and decorative concrete work
to be seen in many parts of the United Kingdom, designed \>y some of the leading London and
provincial architects.

Madame Tussaud's Exhibition is mainly constructed of red concrete dressings. The whole of
the exterior dressings and interior constructional work of Upton Church, Romford Road, Essex, is
composed of red concrete blocks ; and the chancel and transept arches, with the clerestory windows,

5o8

Plastering — Plain ami Decorative.

are in the same material. The majority of the bosses were carved in situ. Blocks for the bosses
were cast and carved as soon as fixed, while the blocks were green. A few bosses, modelled by
my son, J. Millar, were used. Messrs Banks & Townsend were the architects. The wfjrk was done
under my supervision. The fa9ade of the Colosseum at Dalston, London, is decorated with
concrete blocks enriched with elephants', horses', and lions' heads, and figure panels, &c., all cast in
a dark red colour. The work was carried out by Wilkes' Metallic Concrete Compan>-, under my
supervision. I am also responsible for the major portion of the modelling. Mr A. Brandreath was
the architect.

MOULDIXCS C.\ST "IN SITU." — Casting cornices, copings, &c., in situ (a process originally
introduced by the author) is now frequently employed for concrete. Mr T. Potter, in his book,
"Concrete: Its Use in Building," says: "The in situ system of performing this class of work was
introduced b\- Mr Millar, and carried out to a large e.xtent on the Redcliffc estate, West Brom]jton,

Fig. I.

No. 203.— Sections of Moulds for Casting Conxrete Moulding " in situ.''
-Combined IMaster and Wood Moulds for a Cornice. Fig. 2.— Wood Mould for String Mouldings.

Fig. 3. — Mould for

Coping. Fig. 4.— Mould for Saddle-back Coping. Fig. 5.— Mould for Coping with Chamfered Angles.

twenty to twenty-five years ago, and is probably nearly or quite the earliest attempt of the kind in
this country." The advantages of this system over shop cast work are, that the work is readily
done, and the cartage or moving from the workshop to the building, and the fixing, are dispensed
with.

Illustration No. 203 shows the method of constructing and fixing various kinds of casting

moulds for in situ work.

Fig. I shows the section of a cornice, casting mould, and supporting bracket. Wood muulds
are generally used for small or plain mouldings, but where the profile is undercut or of an intricate
nature, a plaster mould is preferable, as it is easier and cheaper to construct a plaster mould than cut
the irons which are necessary for a wood mould for a special design. Fibrous plaster moulds may
be used for this class of work, but to illustrate another method a combined wood and plaster mould
is gi\en. M is a moulding board used to strengthen the plaster profile, and on which it is run. The
board may be made in two or more pieces, each about i inch thick, and in width according to the

Casting Concrete Mouldings in Sitti. 509

depth of the moulding, and in length as required, the whole being held together by cleats II, which
are nailed about 3 or 4 feet apart. Broad-headed nails are then driven in at random, leaving the
heads projecting, to give a key for the plaster profile P. The jjrofile is then run with a reverse running
mould. It will be seen that this profile is undercut, therefore a loose piece L is required to enable
the mould to draw off the moulding. The reverse mould and loose piece are constructed in the same
way as described under the heading of " Reverse Mouldings." It may be here remarked that it is
sometimes useful to have an "eje " inserted in the loose piece to give a better hold for the fingers
when taking the loose piece off the moulding. The eyes are made by twisting a piece of strong
wire round the handle of a tool brush, leaving one end in the form of a ring, and the other bent out-
wards so as to form a key. The eyes are fixed about 3 or 4 feet apart, the fixing being done by
cutting a hole in the loose piece and bedding the shank of the e\-e with plaster, and then cutting a
slot in the main part of the mould to receive the ring of the eye as shown at E. The mould is held
in position by the bracket B, fixed 4 or 5 feet apart. The mould is further secured by the stay S;
the other or inner end of the stay is fi.xed on to the main wall. It will be understood that a plaster
mould for this purpose should be dry and hard, and then well seasoned with linseed oil, or with a
hot solution of paraffin wax. After the mould is fixed in position it is oiled, and then the concrete
C is filled in, taking care that the surface of the mould is first covered with a thin coat of neat
cement. The mould may be oiled with paraffin oil ; but if the mould is inclined to "stick," oil it
with " chalk oil," i.e., paraffin oil and French chalk, about the consistency of cream.

When the concrete is set, the brackets are removed, and the mould taken off. The mould in
this case would draw in the line of the arrow A. The loose piece is then taken off. It is here that
the use of the eyes will be found. Before removing the brackets it is ad\'isable to prop the mould,
in case it may drop off and break the fragile portions of the mould or parts of the cornice. A heavy
mould hanging in this position, especially if the profile is flat, or in good working order, is apt to
drop, hence the necessity of props. If the mould clings, or, as more generally called, " sticks fast,"
gentle tapping with a heavy hammer will ease or spring it, and allow it to be taken off. A heavy
hammer is more effecti\e in making the mould spring than a light hammer, as the force required for
a light hammer is apt to injure the mould. This is why a hea\-y hammer with a flat head is best for
plaster piece moulding.

Fig. 2 is the section of a string moulding with the casting mould and bracket. A chase is
formed in the brickwork to allow it to bond, and the joints and the surface of the brickwork are cut
out and hacked to give a further ke\- to the moulding. M is the mould (in this case made of wood).
The profile is drawn without any undercut parts, so as to allow the mould to draw off in one piece.
B is the bracket, and C is the concrete. The same directions for casting Fig. i apph" to this and the
other mouldings here shown. A drip member, as shown at the to[) member of both cornices, is
generally used for exterior mouldings, to prevent the water running over the wall surface.

Fig. 3 is the section of a wall coping and the casting moulds. M is the mould, a similar one
being used for the other side. A mould for this purpose is best formed with flooring boards about
I inch thick, and fixing them together as shown. The drip D is readily formed by sawing an inch
bead through the centre, and nailing it on the bottom. Two forms of brackets, B and H, are here
given. One is cut out of the solid, and the other made of two pieces of wood nailed together.

Fig. 4 is the section of a casting mould for a saddle-back coping. K is a quarter-round piece
of wood fixed in the angle of the mould to form a cavetto, which is sometimes used in copi ngs
D is an angular-shaped drip, sometimes used in place of a circular one. T is part of a template used
for forming the saddle-back of the coping.

5IO Plastering — Plain and Decorative.

Fig. 5 is the section of a mould for a coping with splayed or chamfered angles, s is a triangular
strip of wood fixed in the angle and the top of the mould to form the splays, and I) is a circular drip.
Concrete mouldings that are deeply undercut or intricate in profile maj- be cast in situ b\- the
use of the "Waste Mould Process," as described in Chapter IX.

Modelling in Fine Conxrete. — Figures of the human and animal form, also emblems,
trade signs, and buildings, are now being made in fine concrete. The work ma>- be executed
ill situ, or in the modelling shop, and then fixed in position. For important works a plaster model
is made first, and then placed in position, so as to judge of the effect before committing it to the
permanent material. For this process the model is first modelled in clay, and then it is waste-
moulded, and a plaster cast obtained. -After the model is approved it is moulded, and then cast in
the fine concrete. The material is composed of Portland cement, and a light, but strong, aggregate ;
and the cast is made in a similar way to that described for casting vases. The material may be
coloured as required to suit the subject. The general method of executing figures " on the round "
in fine concrete or Portland cement is to model the figure direct in the cement on an iron frame,
and then to fix it in its permanent position. This is elifected by first making a full-sized sketch of
the proposed figure, then setting out on this the form of the necessary' ironwork to serve as frame
or skeleton to form an internal support. This iron frame also forms a core to enable the figure to
be made hollow, and serve as a permanent support for thin parts and extremities of the figure.
The quantit)-, size, and form of the iron frame is regulated by the size, form, and position of the
figure. For instance, if the model of a full-size lion is required, first make a rectangular frame to
suit the feet of the lion and the base on which the figure stands. The base frame is made of iron
bars, li inches wide by \ inch thick, fixed on edge. Then set out four leg-irons, and connect them
on the base frame, and then set out one or two body-irons, and connect them with the leg-irons.
After this set out a looped piece to fit the contour of the neck and head, and fix it to the body-iron.
Now set out the tail-iron. This is best formed with an iron pipe, and it should be made to screw
on to the body-iron. This allows the tail to be unscrewed when the model is finished, and screwed
on after the model is fixed in position, thus enabling the model to be more freelj- handled, and
with less risk of breakage when moving and fixing in its ]jermanent position.

Having made the frame, place it on a stout modelling board, keeping the base frame from
I to 3 inches above the board, according to the depth of the base ; the frame being temporarily
supported with four pieces of brick or stone. This is done to allow the base frame to be en\-eloped
with concrete. This done, fix wood rules, cut to the depth of the base, on the board, so as to form
a fence on all sides of the base. Then fill in the base with concrete; and when this is set, proceed
with the coring out, .so as to obtain a hollow model.

In order to decrease the weight of concrete figures " on the round," and to enable them to be
more easily handled and hoisted when fixing them in their permanent positions, thej' should
be made hollow. This is effected by making a rough skeleton frame with hoop-iron, or with wire-
netting, for the body, neck, and head, and other thick parts. This metal skeleton must be built on
and securely fixed to the main iron frame. The whole, or parts of the figure, may also be cored out
with .shavings or tow, and held in position with tar bands or canvas strips, dipped in plaster.
Tow is an excellent material for forming cores. By making up the inner parts with dry tow, and
then dipping tow in plaster for the outside coat, the core can be made to any desired shape, and
also leave the necessary thickness for the concrete. To prevent the material slipping down b\- its
own weight, pieces of iron or wood, in the form of crosses, are fastened with copper wire or tar rope
to the iron rods, which are used as single supports. These iron or w'ood pieces must be fixed in

Modelling in Concrete. 511

all directions, and in such a way that the material is held up by them. For small extremities, such
as fingers of human figures, beaks of birds, fins of fishes, horns and tails of animals, iron rods should
be fixed on the main frame, and the parts to be covered with cement must be notched or bound at
intervals with copper wire or tar rope. The distance between the core and the finished face of the
figure is of course the actual thickness of the model. This thickne.ss may vary from i inch to
3 inches, or even 4 inches at some jmrts. .An average thickness of 2 inches will be sufficient to
give the requisite strength.

When the core is made, cover it with a coat of Portland cement and old lime putty, in
the proportion of 3 of the former to i of the latter, and add sufficient tow or hair to give
tenacity. If there are open spaces in the skeleton ironwork, bridge them over with bits of tiles
and cement. The whole surface, after being coated, must be well scratched with a nail, to give a
key for the roughing-out coat. This scratch-coat must be allowed to set before proceeding with
the actual modelling. The stuff for roughing out is composed of 2 parts of Portland cement and
I part of fine aggregate. Crushed bricks, stone, or pottery-ware passed through a sieve having
a ^-inch mesh may be used as aggregates. The finishing stuff is composed of fine sifted Portland
cement. The addition of a fifth part of old lime putty to the cement makes the stuff more
mellow, and works freer and sweeter. The modelling is done as described for in situ work. The
finishing coat can be coloured to any desired tint, as already described.

Among the many recent e.xamples of this class of work may be mentioned a deer which
stands on the Buccleuch Memorial at Hawick, modelled by my nephew, W. Brown, of Edinburgh.
Natural horns or antlers were used for this deer. During the last decade numerous symbolic
figures as signs for London public-houses have been executed in fine concrete or Portland cement.
A fine example of this class of work is a bull nearly life-size for " The Black Bull " at Stratford,
modelled by Gilbert Seale. Other examples are a swan for " The White Swan," Fulham, modelled
by F. Blount ; also a cock for " The Cock " at Fulham, modelled by W. Batchelor, shop-foreman
for J. Bickley ; and a lion — over life-size — for "The Red Lion," Fulham, modelled by the author in
1890 for J. H. Squires, Esq.

Concrete Fountains. — Fine concrete is an excellent material for the construction of
fountains. It is obvious that a vast amount of cutting and consequent waste of material is involved
in the executing of fountains, " on the round," when natural stone is employed. Saving of material,
and a corresponding reduction in the cost, is effected by use of a material that can be easily cast,
and is at the same time durable and impervious. These qualities combined are found in artificial
stone composed of fine concrete. Being readily made in large blocks (any sized basin can be made
in one piece), there is no jointing required, as is the case with terra-cotta, which is another form of
artificial stone. Fountains composed of fine concrete are made in a similar way to that described
for making and casting vases. An elaborate fountain which was on view at the Building Trades'
Exhibition, London, 1887, was about 9 feet high, and 6 feet in diameter. It was enriched with
cupids, dolphins, shells, water lilies, and leaf foliage. The whole was cast in fine red concrete.
It was modelled by F. Blount, and moulded by W. Flavell.

Concrete Tanks. — Concrete tanks to contain water, and for a variety of manufacturing
purposes, are now largely in use. They are strong and durable, and having hard smooth surfaces,
they are easily washed and kept clean. Being impervious to vermin, damp, and atmospheric
influences, they are the coolest and most sanitary water cisterns that can be used. Cattle troughs
are best made in concrete. I have used concrete tanks as water and silicate baths for indurating
concrete casts, and during their constant use for over a decade no signs of cracks or damp were

512 Plastering — Plai)i and Decorative.

ever visible. Thc\- were made in one piece, varj-ing in size from 6 feet up to i8 feet long, 3 feet to
7 feet wide, 2 feet 6 inches to 4 feet high, and from 3 to \\ inches thick. Some were cast, but the
large ones were made in situ. The method of construction (for in situ work) being simple and
exjjeditious. the total cost is small. For a tank 9 feet long, 4 feet 6 inches wide, 2 feet 6 inches
high, and 3.^ inches thick, first frame up wood sides and ends to the above length, width, and
height, then make inside boards, the lengths and widths being the same as above, less the tank
thickness, and the heights less the bottom thickness. The sides and ends are hung by means of cross
battens laid on the upper edges of the outside framing, and kept in position with inside stays.
This leaves an open and continuous space at the sides, ends, and bottom. The constructive
materials are i part of Portland cement and 2 of fine slag or granite, gauged stiff, and laid over
the bottom. Next, the open sides and ends are filled up, taking great care that tlic whole mass
is thoroughh' consolidated b)- ramming. The stuff for the sides and ends should be laid in la)^ers
from 6 to 8 inches deep, each layer being well rammed before the ne.xt is laid.

The angles are strengthened by inserting angle irons during the process of filling in. As
soon as the concrete is set the inner boards are removed, and if the surface is smooth or dry, it
must be keyed with a coarse drag or a sharp hand pick. It is then swept and wetted to cleanse
it and stop the suction, so as to ensure perfect cohesion, and allow the final coat to retain its
moisture during the process of trowelling and the stuff setting.

The finishing coat is composed of neat cement, the finer ground the better, as percolation
through concrete made with a finely ground cement is less liable than when made with a coarsely
ground cement.

The final coat is laid about fV inch thick, and preceded bj- brushing the surface with liquid
cement to fill up all crevices, and afford better adhesion between the surface and the final coat.
When the stuff is firm, it is well trowelled to a fine and close surface. The outer boards are then
removed, and the surface finished in a similar way.

CON'CRETE Sinks. — Concrete sinks can be made to any desired size or form. The)- are
cast in wood or plaster moulds, and are composed of i part of Portland cement to 2 parts of fine
crushed granite or other hard aggregate. They are made with rebated holes for traps. The ordinary
sizes are as follows : — 2 feet 6 inches by i foot 8 inches ; 2 feet 9 inches by i foot 8 inches ; and
3 feet by 2 feet, all 6 inches deep, and from 2 to 3 inches thick.

Garden Edgixc. — Plain and ornamented edgings are now made in concrete. Thej- are made
in various lengths. The most useful size is 3 feet long, 6 inches deep, and 2 inches thick. They
can be made to any curve, and tinted to any shade.

Concrete V.\SES. — During the last half-century thousands of vases, composed of fine
concrete— commonly called " artificial stone " — have been used for the decoration of buildings and
practical u.se in gardens, conservatories, &c. For vases that are cast in sections the thickness of
large and open parts, such as the " body," are regulated b}- means of a plaster core, which is placed
in the open mould. The contour of the core must be so arranged that the ca.st will draw from the
core, or vice versd. For some forms of vases, the core must be made in pieces similar to a piece
mould. The method of making, moulding, and casting — the latter by the aid of a template instead
of a core — is described in Chapter IX.

Concrete Chimnev-PIECES. — Chimney-pieces of all sizes and shapes are now extensively
made in fine concrete. They are generally made in wood moulds, plaster moulds being let in the
main mould for ornamental parts. They are often made in coloured concrete.

Coloured Concrete. — Concrete casts, also work laid in situ, can be coloured to imitate any

Colony ed Concrete. S'S

natural stone. This is effected by mixing mineral oxides of the required colour with the cement
used for the .surface coat. The colour coat should not exceed \ inch in thickness, as oxides are too
expensive to use for the entire thickness of the cast. The quantity of oxide to be added to the
cement depends upon the strength of the oxide. Some are much stronger than others. Five per
cent, of a strong oxide will impart a close resemblance of the desired colour to the concrete, but
a weak oxide will require from lO to 15 per cent., and even 20 per cent., to obtain the same colour.
Some of the red oxides range in colour from scarlet or Turkey red, gradually deepening to
chocolate. Some oxides contain 95 per cent, of pure ferric oxide, which Is made from copperas, or,
scientificall}- speaking, sulphate of iron. This is a by-product, and Is frequently evolved from waste
acid liquors at tinplate works, and is obtained in large quantities from South Wales. This kind
of oxide is far more suitable for colouring concrete than ochres and most of the earthy oxides.
Earthy colours, like Venetian red and umber, soon fade and have a sickly appearance. The oxides
should be intimately mixed with the cement in a dry state before it is gauged. The mixing is
generally done by hand, but better results are obtained by the use of a grinding machine. It is a
safe plan to try various proportions of colour and cement and gauge small parts, and when set and
dry select those most suitable for the desired purpose. All cast work, as soon as extracted from
the moulds, should be examined, and any blubs stopped and chipped parts or other minor defects
made good while the work is moist or green, using neat cement and colours in the same proportion
as u.sed for the surface stuff. Coloured surfaces may be greatly improved by brushing the cast as
soon as set with a solution of the same colour as used for the surface coat. A colour solution,
made by mixing the colour with water and a solution of alum, is very useful for colouring Portland
cement, with or without sand. If this colouring solution is brushed over the surface while it is
moist or semi-dry, a good standing colour can be obtained without mixing colour with dry cement.
This method will be found useful for sgraffitto, &c.

A novel and colour-saving method, for colouring the upper surfaces of slabs or other flat
casts, is effected b}- first filling in the mould in the usual way, then placing the coloured cement in
a dry state in a hand sieve, and then violently shaking or tapping the sides of the sieve, so as to
sprinkle the coloured cement uniformly over the surface until it is nearly ^^ '"'^h thick. The
surface is then trowelled In the usual way. The sprinkling must be done as soon as the main body
of the stuff is ruled off, so as to obtain a homogeneous body. Another and a novel method which
may be advantageou.sl)' employed for finishing slab or other large surfaces in a mould is
as follows : — A fine finished face Is more readily obtained by using a smoothing knife (for
brevity termed a "shaver") than by a trowel. A shaver is a piece of polished steel about
3 Inches wide and f inch thick, the length being regulated according to the width of the
mould, and allowing about 8 inches at each end for handles. For instance, for a slab 2
feet wide, the shaver should be 3 feet long. This allows 2 feet for the surface of the cast,
3 Inches to bear on the rims of the mould, each li inches wide; 8 inches for the handles,
each 4 Inches long ; and i inch for play. One edge or side is cut to an angle of 45°, so as
to form a cutting edge. The method of filling in, colouring, and finishing the surface of the
slab is as follows :— First fill in the mould with the concrete, ramming and beating it as already
described, until the stuff is about tV inch above the mould rims, then clean off the stuff on the rims
with a wood template (rebated to fit the width of the rims), and lay the shaver flat on the rims,
keeping the cutting edge outwards, and then push it forward, keeping it flat on the rims, so as to
shave off the superfluous stuff. This done, sprinkle the coloured cement, with the aid of a sieve,
until about ,V '"ch thick ; then clean the rims again, and pass the shaver forwards and backwards

514 Plastering — Plain and Decorative.

twice or thrice, which will leave a straij^ht, smooth, and uniform-coloured surface. This method
effects a considerable savinij in the amount of oxide and of time. The thickness of the colouring
stratum is reduced mechanically to the minimum (about j^V inch), which is all sufficient for
colouring purposes where the surface is not subjected to frictional wear.

As alread)- inentioned, bullocks' blood mi.\ed with cement gi\es a near resemblance to red brick,
but it is not a desirable material to work with, and the same effect can be obtained by the use of red
oxides. Red sand, brick, and stone, all finel}- ground. ha\e been employed for colouring cement
surfaces, but if too fine or in large quantities the\- weaken the surface ; and if coarse-grained they
])ossess little colouring effect, because the particles are liable to show singly, causing a spotty
appearance, or the cement entirely covers the surface of each particle of sand. Powdered glass,
marble, flint, alabaster, metal filings, and mineral colouring can be effectively emploj-ed for colour-
ing concrete surfaces by mixing with the cement u.sed for the surface coat. The surface is improved
b)- rubbing and stoning, also polishing, after the work is dr\\ Mr Lascelles obtained a patent for
this object in 1887. Other methods and quantities of colours for colouring Portland cement
surfaces are given on page 190.

I'lXINc; Blocks. — Concrete fixing blocks do not shrink, war]), or rot. Consequently the\'
are superior to wood fillets, &c. They are ])rincipa!l\- used in concrete floors, stair landings, and
walls, as bearings and fi.\ing points for wire-lathing and fibrous plaster work. Floor boards may
also be fixed to them. They are also built into brick walls for similar purposes, as well as for
external wall tilings. For ceilings, stair soffits, and landings, the blocks arc laid on the centrings
where required, and permanenth- secured hy la\-ing concrete between and over them. For bearings
and fixing flooring boards, the\" are secured flush with or abo\-e the upper surface of concrete, as
required. Fixing blocks are made with splayed sides, so as to give them a dovetailed section,
and make the key when embedded with concrete. To increase the ke\'ing powers the sides are
sometimes grooved. They are made in various sizes from i to 3 feet long, 2 to 3 inches thick,
2 to 3 inches wide at the top, and 3 to 4 inches wide at the bottom. These blocks are cast in
wood, iron, or plaster moulds, and are composed of i part of Portland cement to 5 of fine crushed
coke-breeze. The breeze and cement are sometimes ground together in a pug-mill.

Lintels. — Concrete lintels and beams are fast superseding those made of stone and wood.
Lintels are generallj- cast and then fixed. A mould for casting lintels is shown on page 506.

CONXRETE Walls. — Many ingenious plans have been introduced as substitutes for wood
framing for retaining concrete while constructing walls and partitions. The most simple method
is as follows : — Cast a number of concrete angle slabs with an L section, and place them le\-el in
contrary- directions thus [^ CI. spaced to the width of the proposed partition or wall until the
desired length of wall is comjileted, and fill in the openings \\\\.\\ rough concrete. When set, place
another row on this (taking care to break the joints b\- overlapping), and so on, until the desired
height is obtained. Concrete for walls formed in situ should be deposited in layers, taking care
that each la\-er is thoroughlj- rammed and ke\-ed, as described under the heading of " Ramming."
A suitable finish for ordinarj- purposes, for rough walls built in situ, may be obtained b\- "rough
trowelling." This is done by first gauging i part of Portland cement, i part of old lime putt}-, and
2 parts of sand. The adding of lime renders the stuff more plastic and eas)- to work, without
decreasing the impermeability of the work. This " limed cement " is applied with a hand-float,
and is thoroughly worked into the crevices of the concrete, but leaving no body on the surface.
The surface is then finished by brushing with a wet stock-brush. The walls should be well
wetted before the stuff is applied.

Concrete JValls and Strong-Rooins.

D»0

Strong-Rooms. — Concrete is frequently employed in the construction of strong-rooms that
are situated underground, and are rendered damp proof as well as burglar proof, which is useful
for the storage of documents. An excellent example of this class of work can be seen at the
Credit Lyonnais, London, executed by T. W. Potts, who has executed many concrete works.

Concrete Coffins and Cementation. — The great improvements in the manufacture
of Portland cement during the last decade has so cheapened and improved the quality as to
bring it more and more to the front as one of the most useful and important materials for a
variety of purposes. One of the latest uses found for it is in the construction of coffins, by the
author, whose invented and registered idea was that such a coffin, made of specially prepared
metallic concrete, would be impermeable, and practically indestructible, and that it would obviate
the danger of spreading the poisons of disease, by preventing the escape of noxious gases. The
lid having a strong piece of plate glass embedded in the concrete, and directly over the face,
enabled the mourners to see the features of the departed. The edge of the open coffin had a sunk
groove, and the lid a corresponding projection, only smaller, to allow for a coat of fine cement.
When the joints were bedded and pressed together until the excess cement oozed out, the coffin
was hermetically sealed. The coffin could be left uncovered by cement for identification, and so
that friends could view it until the time of removal to the cemetery. The face could then be
covered with quick-setting cement, which, joining with the other portion of cement, would per-
manently embalm the body, which would further be protected by fixing the lid in a similar way. If
the properties of this class of coffin are taken into consideration, the expense will be comparatively
less than that of wood. If expense is not a special consideration, the coffin can be enriched with
armorial bearings or other devices. The concrete may also be polished like real granite. One
objection was raised as to the weight, but the old stone coffins and those of oak lined with lead
were also heavy. Besides, the weight would be a protection against body-snatchers ; and bearing
in mind that a coffin is only moved about once in a lifetime, or rather at death, the question of weight
is unimportant. Cementation, from a sanitary point of view, would be equal if not superior to
cremation. In case of an epidemic, the coffins could be cemented at once, and stacked in the
cemetery until graves or vaults were prepared for them. It may be safely said that it is a clean,
safe, effectual, rapid, and sanitary method of disposing of the dead. As this coffin was exhibited
for the first time at the Building Trades' Exhibition in the jubilee year (1S87), and being requested
by Mr T. Grover, the Chairman of the Patent Paving and Eureka Concrete Company, to provide a
novel advertisement for the Compan\-, for which I was then acting as manager, I named it " The
Jubilee Coffin." If their manufacture should not cause any great amount of extra employment for
plasterers, the latter can at least make their own coffins, in frosty weather, when most works are
stopped, and they could use them as baths during their lifetime.

Stonette. — Stonette is a composition of Portland cement and fine aggregate, to imitate any
kind of stone, and so made that it can be carved the same as natural stone. The Portland cement
must be thoroughly air-slaked, finely sifted, and gauged with the natural aggregate in the proportion
of 2 of cement to 7 of aggregate. The aggregate is composed of finely crushed natural stone, the
same as that to be imitated. This should be passed through a fine sieve. It is necessary, when
imitating some stones, to add a small portion of oxide to counteract the colour of the cement. If a
very white stone is being imitated, the addition of a small proportion of whiting or French chalk,
or well-slaked white limestone, is necessary to obtain the desired colour. The material should be
gauged stiff, and then well rammed into the mould. The carving is best done while the cast blocks

are green.

Si6 PlastcyiiiiJ — Plain and Decorative.

Tll.li; Fixing. — Tile fixing is in some districts a separate branch of the building trade,
but it is generally recruited from the ranks of plasterers, and in some districts it is done by
plasterers. As regards the process of placing the tiles, it is best to work from the centre of
the space, and if the design be intricate, to lay out a portion of the pavement according to the
plan, upon a smooth floor, fitting the tiles together as they are to be laid. Lines being stretched
over the foundation at right angles, the fi.xing may proceed, both the tiles and the foundation
being previously soaked in cold water, to pre\ent the too rapid drj-ing of the cement, and to secure
better adhesion. The border should be left until the last. Its position and that of the tiles are to be
obtained from the drawing, or by measuring the tiles when laid loosely upon the floor. The cement
for fi.ving should be mixed thin, in small quantities, and without sand. It is best to float the tiles
to their places, so as to exclude air, and fill the space between them and the foundation. For fixing
tiles in grate cheeks, sides and backs of fireplaces, &c., equal jjarts of sand, jalaster, and hair mortar
ma\- be used. These materials are sometimes mixed with hot glue to the consistency of mortar.
The tiles should be well soaked in warm water. Keen's or other white cements are used as fixing
materials for wall tiles, neat Portland cement fvcry often killed; being generalh' used for floor
work. Tiles may be cut in the following manner : — Draw a line with a pencil or sharp pcjjnt where
the break is desired, then placing the tile on a form board, or embedding it in sand on a flagstone,
tap it moderatel)- with a sharp chisel and a hammer along the line, up and down, or scratch it with
a file. The tile may then be broken in the hand by a gentle blow at the back. The edges, if
required, may be smoothed by grinding or b)- rubbing with sand and water on a flat stone. Tiles
may also be sawn to anj- desired size. Cement should not be allowed to harden upon the surface
of the tile if it can be prevented, as it is difficult to remove it after it has set. Stains or dirt
adhering to tiles maybe removed by wetting with dilute muriatic acid ("spirits of salts "), care
being taken that the acid is all wi[jed off, and, after washing, the superfluous moisture must be
wiped ofi" with a clean dry cloth. In order to obtain a sound and straight foundation, which is
imperative for good permanent tile fixing, the substratum, whether on walls or floors, should be com-
posed of Portland cement gauged with sharp sand or similar aggregate in proportion of i of the
former to 3 of the latter. The surface must be ruled fair and left rough, so as to form a fair bed
and kej' for the fixing materials and tiles.

Patent Non-Slii-perv Step.s. — A novel and effective method of rendering concrete steps
and landings non-slippery has been recently patented by Messrs Burness & Son, plasterers,
Montrose. Indiarubber cubes, about half an inch in diameter, and a screw-shaped sinking on the
side, are inserted in the moist concrete until the tops are nearly flush with the concrete surface.
For cast steps the cubes are temporarily fixed on the face of the mould, and then the concrete
is laid in the usual way. When the concrete is set a corresponding screw cut is formed in the side
of the concrete cube holes. The cubes can be extracted or raised by simply unscrewing them with
a two-pronged fork. When the cubes wear below the concrete surface the>- are raised for further
use by screwing them up, and so on until thc>' are finally- worn out, after which they are replaced
by screwing in new ones. These rubber cubes, while affording a sure foothold, also decrease the
wear of the concrete surface, besides providing a soft tread and a noiseless traffic. The cubes are
placed in two or more rows, and from two to three inches apart. Messrs W. B. Wilkinson & Co.,
Newcastle and London, are the agents for the rubber screw cubes.

CHAPTER XX.
RUDIMENTARY GEOMETRY AND ARCHITECTURE.

Practical Geometry as applied to Plaster Work.— To Set out a Template for a Flat Arch— To
Construct a Template without a Radius— To Find the Centre of an Arch— To Describe an
Ellipse— To Describe a Flat Ellipse— To Set out a Flat Arch— To Form an Oval from
Circles— To Form an Octagon— To Set out Arches : Flat-Pointed Arch, Semicircular Arch,
Flat Arch— To Describe a Gothic Arch— Radius of Segments by Figures— The Elements of
Architecture— Mouldings— To Describe Roman and Grecian Mouldings— The Grecian and
Roman Orders : Doric, Tuscan, Ionic, Corinthian, and Composite— Heights of Columns-
Diminution of Columns — Proportion of Entablatures— Pilasters — Impost and Archivolt
Mouldings— Balusters— Setting out Balustrades— Copying Mouldings.

Practical Geometry as applied to Pla.ster Wcjrk.— Geometry is an important factor in
most building processes. No part of a building or of a drawing can be laid down or proper!)-
understood without a knowledge of geometry, nor can any mechanical branch of the building
department be constructed without some assistance from this branch of science. I have seen men
unacquainted with geometry spend several hours in the solution of problems which could have been
solved in about a quarter of the time if geometry had been employed. It is not difficult to acquire
a knowledge of this science ; indeed, great progress in its study could be made by simplj- employing
the time frequently wasted in the endeavour to solve a simple problem in a roundabout way. As
a matter of fact, its principles are frequently used unconsciously by some workmen, and though
forming the basis of most designs, its utility is not fully acknowledged. There are so many good
and cheap works on the subject that it is only necessary to give a few examples, which bear upon
almost everyday work of the plasterer and artificial stone manufacturer. The examples here
given will be found useful when setting out artificial stone work, cement facades, and model
making ; also for " solid " and fibrous plaster work.

Illustration No. 204 elucidates the method of setting out ovals, arches, octagons, and templates,
by lines.

To Set out a Template for a Flat Arch. — Fig. i shows the method of forming a
cur\-ed line without using a radius, which may be used for setting out a template to run a moulding
on a flat arch, or for forming centring for concrete work. The span and rise of arch being given,
first divide half the span into si.x or more equal parts, divide the rise into the same number of parts,
and number all as shown ; then draw lines from i to i, 2 to 2, 3 to 3, 4 to 4, 5 to 5, and 6 to 6, and
their intersections will give the desired cur\-e. Repeat the same process for the other half

To Construct a Template without a Radius (Fig. 2). — Suppose the span of this curve
to be 40 feet long from A to B, and it is required to raise it i foot 6 inches at C. Draw a line from
C to B, divide this line into two equal parts, and at the di\'ision i raise a line at right angles to C H
one-fourth of the height of the proposed rise, which in this case would be 4^ inches ; then bisect
the line from i to B and from i to C, which will give the points 2 and 3, raise lines from these

5i8

P/asfcn'i/g — Plain and Decorative.

points one-fourth of the last division, which will be i^ inches. The same process is repeated until
there are sufficient points when connected to form a regular curve.

To FiXD TIIK Centric (Fig. 3). — Take ah as the span of an arch, and D and c its
perpendicular height. The straight lines passing from .\ to c and i' to i! are called cliords. To
find the centre, first draw the chords from the springing B to the centre C, and A c. Then bisect the
chords by the perpendicular lines P F and P E. The point where they intersect will be the centre
from which to describe the arch. For cement or concrete work the joints are set out by the same
process.

To Construct an Ellipse (Fig. 4).— Take a b as the span of the arch, divide the base line
.\ B into three equal parts ; on c as a centre, with the radius C I), describe the arch B D, and on E as
a centre, with radius E F, describe the arch A F. Then by the same rule as for Fig. 3 find the centre
P, and on P as a centre join F D. From the point K get the first two joints G F, and from the ]Joint
C get the first two joints i) ii, and from the point P get the remainder of the joints.

To Construct a Flat Ellipse (Fig. 5). — Take a b as the span of the arch, divide the
base line into four equal parts ; on c as a centre describe the arc n i!, and on E as a centre describe

1
1

Fi^.6. -c
No. 204. — Setti.ng out Ov.ai.s, Arches, Octago.ms, ami Templates.

^-^^

the arc A F, from E to c on the base line. Then by the same rule as before find the centre P. On
P as a centre, with the radius p h, join the arc F D ; on c as a centre get the first joint D, and on the
point E get the first joint F, and from the point P get the remainder of the joints.

To Construct a Flat Arch (Fig. 6).— Divide the span a b into any required number of
equal parts, and under A B form the equilateral triangle A B C, then c will be the point from which
the joints of the arch stones must be drawn.

To Form an Oval from Circles (Fig. 7).— First draw the centre line A B, then divide the
line into three equal parts, and from D and C as centres describe two circles, the one intersecting the
centre of the other as shown. From the intersection of the circle at E and f connect the two circles,
thus completing the oval.

To Form an Octagon (Fig. 8).— First draw the centre line A B, then the centre line C D
square to A B ; form the four outer lines parallel to the two centre lines, then form the two diagonal
lines E F and G H. From the centre describe the circle A B C n, then apply a set square to the lines
C D and form one cant, reverse the square to form the others, touching the circle each time. The
cants will then form a true octagon.

Another way is to first form a square (made to the desired size of octagon), and from each angle

The Rjidinients of Geometiy. 519

draw a segment whose arc will touch the centre of the square, and from the termination of each
curve draw angular lines, and then erase the angle lines of the square and the circular lines, thus
leaving the desired octagon.

Arches. — The method of setting out the various arches shown on illustration Mo. 205 will
be of service when constructing artificial stone work, also for working fibrous plaster, or Portland
cement facades.

Fl.\T-Pointei) Arch (Fig. ij.— Draw the line A to B at the springing of the arch, divide this
into four equal parts (i, 2, 3, 4). Take i and 3 as centres, and describe the springing arcs at D and
D ; a section of each will form the haunch of the arch. Draw the lines C C from D and D through the
points at i and 3 towards G and G, at an angle of 45 \ Take 3 parts of A to B as a radius, and from
the point G strike E the upper part of the arch from the point at D to F. Repeat the same process
for the other side of arch. The same centres and radius to scale are used when running mouldings
on this form of arch. The moulding may also be run from a template. In this case the template
can be set out by the method given for setting out the arch.

Semicircular Arch. — Fig. 2 illustrates a .semicircular or half-round arch, and the various

?"ig. I.

Fig. 2. Fig. 3.

No. 205. — Setting out Arches.

I'ig. 4-

parts composing it. The width between the piers or abutments is called the "span" of the arch,
and is measured in a horizontal line, called the "springing line," as A B. What is called the rise of
the arch is the vertical distance measured from the centre of the " springing line " to the under-side
or soffit of the arch at the keystone. The highest part of the arch is called the " crown," and the
parts behind the extrados, or outside of the arch, which fill up the space between the abutments and
the line of "crown" of arch, are called the "haunches." C is the "impost" on the abutment, on
which D, the " springer," or first stone of the arch, is placed ; E the " voussoirs," or stones which
form the arch, and are held in position by H, the " ke)'stone" ; F is the " extrados" ; c; the " intrados,"
or under side of arch ; J the " spandrel," or space between the archivolt moulding ; and I is a label
moulding, also termed a dri]j or weather moulding.

Moulded Arch. — Fig. 3 is also a semicircular arch, but having a moulding worked on the
voussoirs. All the joints radiate from the centre C. The moulding is also run from C.

Flat Arch. — Fig. 4 is a fiat arch showing intrados and joints. This arch is set out from
three centres at the points of an equilateral triangle, as follows: — Divide the springing line into three
equal parts. One of these parts forms the side of an equilateral angle as A B C, the angles of which
will be the respective centres as A, B, and C to describe the arch D E and E D.

;20

P/asfcriiii: —Plain and Decorative.

Gothic Arches. — Illustration No. 206 elucidates the methods of .setting out Gothic

arches, &c.

To Describe .\ Gothic Arch (Fig. i).— Take a h as the span of the arch ; upon w as a
centre describe the arc .\ D. On A as a centre describe the arc 15 ix Whatever number of lines
are required may be produced from the same centres. The joints ma>- also be got from the
same points from which the arc is described. For this reason the radius from which the arc is
described is always square to the arch.

To Describe ax Intka-Centred Gothic Arch (Fig. 2).— Take ab as the span of the
arch, with compas.ses on the springing line at A as a centre, describe the arc B c, and on B as
a centre describe the arc A C. Divide the arc B C into five equal parts. On the springing line at E
describe the arc B T, taking care to leave sufficient space for the point, the line A J being the centre
of that point. When the centre E is found, on A as a centre describe the line e I, which
will give the centres all the way round. This affords a ready method to find the centres, so

j> rr C -B

No. 206.— Setting out Gothic Arches, P.v.nels, and Angles.

that wherever the line E intersects the lines A R and A D, these will be the points to strike the
cusps from. The cusps on the other side are set out in the same way.

To Describe an Extra-Centred Gothic Arch (Fig. 3).— Take de as the span of the
arch, bisect the springing line at B E, take any convenient point on D E as a centre according to the
required height of the arch. With L D as a radius describe the line n L, and on the same centre
describe all the outer lines which may be requisite. If three cusps be required, as are shown in
this figure, divide D L into seven equal parts, then draw the lines I N, I M, &c., and on every alternate
line describe the semicircles N M, &c. The joints are also got from the centre. For a Gothic arch
that rises just as high as the opening in width, D E would be the centres for describing the arch.

To CON.STRUCT AN O.G. Arch (Fig. 4).— Take ab as the span of the arch; bisect at C, and
draw c D perpendicular to the base line. Join A H and B H, bisect them at F and E ; on the centre
C describe the arcs A F and B E. By Fig. 3 find the centres P and K, and with the radius E R describe
the arc E 11, and use the same process for the opposite side. For want of space one-half only of the

F hiding Radius Lengths by Figures.

;2i

radius lines K E and P F are shown. Divide the lines A H and B H into three equal parts each, and
from the points draw the lines to c. On the line c H describe the arc B J, and on CI as a centre
describe the arc I J.

To Describe a Trefoil (Fig. 5). — Fir.st draw the vertical line ab, bisect it at j, and on j as
a centre describe the inner circle E R T. Divide the semicircle E B I into three equal parts, and in
like manner the semicircle ARE. From each division draw the centre lines T and R, and on each
line take a centre as at F, F, F, and describe the circles C, B, and D.

To Draw a Rectangular Quatrefoil (Fig. 6). — Draw the line g f, then the centre
line R M at right angles to G F, and parallel to them draw the lines A B, B C, C D, D A ; then draw the
diagonal lines DB and AC, and on these lines as centres describe the circles H, I, j, K, leaving a
proportionate width for the cusps. The intersecting short lines are formed parallel with the
diagonal lines.

To Construct a Gothic Wheel Window (Fig. 7). — Draw a b, then describe the inner
circle according to the size required ; then on either side of A B divide the semicircle into as many
equal parts as there are points required. Draw the lines i, 3, 3, 4, 5, and 6, and on every alternate
line draw the circles C, D, and E, and so on until the figure is completed.

Angles (Fig. 8). — Angles are produced from circles by dividing circles into seconds, minutes,
and degrees. Si.xty seconds make one minute, 60 minutes make one degree, and 360 degrees
make one circle. A circle being divided into 360 equal parts, each part will be one degree, and one
quarter of the circle as shown contains 90 degrees, and is called a right angle. The line dividing
the quarter is an angle of 45 degrees. Each of the smaller divisions contains five degrees.

R.VDius OF Segments by Figures. — The following rules for finding by figures the length of
radius for a segmental arch or panel (the rise and length being given), will be found practical and
quick. If duodecimals are used for computation, the results in most instances will be obtained
still more quicklj-. Suppose the length of a radius rod is required for a segment arch, having a
5-feet span and a 4-inch rise, proceed thus : —

Rule First. — Reduce both lengths to inches, the inch being the lowest factor ; then divide the
square of half the span by the rise (that is, take half the width and multiply it by itself, and
divide by the ri.se), then add the rise and divide by two, thu.s —

Half span 30 in.

Rise 4 in.)9oo

Rule Second. — Square half the span, and
divide by twi.ce the rise, and add half the rise,
thus—

30 half span

225

4 in. rise

Twice ri.se 8 900

2)229 diameter in inches

I 14^ in. =9 ft. 6i in. radius.

1 1:

Half rise

12^1 14^

' 9 ft. 6i in. radius.

Rule Third. — Add together the .square of the ri.se and the square of half of the span, and divide

bv twice the rise, thus —

^ft.-+2 ft. 6 in.- i + 6i 229

T^YTk. = -| = 74 = 9M. or ft. 6 >n. and .V

52:! Plastering— Plain and Decorative.

Should ci-hthsofan inch occur in the measurements of the span and rise, reduce the len-ths to
eighths, and proceed by an\- of the abo\e rules.

Angle Brackets.— The method of setting out angle brackets, \\hich is shown on the
annexed illustration (No. 207), will elucidate the method of setting out angle ribs, and enable
plasterers to set out angle or mitre brackets or "laths" for fibrous plaster work, and templates for
floating screeds, and running mouldings on surfaces which are circular on plan or elevation, or

on both.

The method of setting out a cove bracket at right angles is shown at Fig. i. Let AC be the

Xo. 207. — Setting out Angle Brackets ior Coves, &c.

I^rojection, and c B the arc or profile of the cove. Draw the base line A B, and make A D equal to
AC, then from D to B draw the diagonal line, which gives the base line of the angle bracket.
Divide the profile C B into any number of equal jjarts, as here into six (the more the better and
exact the operation). From these points draw lines parallel to C .-\, cutting both .\ \\ and D I', in as
many points, thus dividing the base line of the angle bracket 1>H into the same number of equal
parts. P'rom the points in D B draw lines at right angles or perpendicular to D B, and make the
lengths of the perpendiculars respectivelj- equal to the lines contained between the base A H and the

profile C 1!, and through the |x)ints of e.xtension, with the aid
of a flexible rule, draw the curve E B, thus forming the profile
of the desired angle bracket.

The method of setting out the angle bracket of a c_\-ma-
recta or " ogee " is shown at Fig. 2. This is effected b\' a
similar operation as used for Vvg. i. These figures are sufficient
to show that angle brackets or ribs for any form or profile of
front brackets can be set out by the same method.

The method of setting out an angle bracket for a cornice

is effected in a similar manner, as already described, and

as shown by the annexed illustration (No. 208). Angle

brackets or ribs for exlernal mitres, and for obtuse or acute angles, are set out on the above

|)rinciples.

The Ei.e.ment.s of Architecture. — The elements of architecture here given are intended
to embod)- a \ariety of examples in the difierent stj-les, and of the methods by which they are
drawn, all of which is necessarily more or less directl}' connected with the plasterer's and modeller's
craft. In architecture there are certain elementar)- forms which, though simple in their nature and
few in number, form the principal basis of ever)- composition. Of these there are two distinct
kinds, the first consisting of the essential parts which are necessary in construction. The sub-

No. 20S. — Sktting out Angle Brackets
FOR Cornices.

The Riidinieiits of Architectiiye.

5^3

FUUt or List

^tra^al ar^ecd

3n:

Torus

mMM

Echwus

Ovoh or (Jiuirter roujid

servient parts contri\ed for the ornament of the constructional parts, and intended to unite them
gracefully together, are usualh- called mouldings, and constitute the second kind. In architecture
there are certain qualities which may be classed as follows : — Magnitude and strength, which
affect the eye ; order and harmony, which affect the understanding ; richness and simplicity, which
excite the affections, in which taste is the principal guide. These qualities answer to the two
divisions which writers on architecture have usually adopted, namely : — Construction, in which the
chief requisites are order and harmony; decoration,
whose requisites are richness or simplicity,according
to the nature of the composition.

Several modellers and plasterers have risen to
be architects, among whom may be mentioned Jean
Goujon, a French modeller, who was an architect
in the reign of Francis I. He was one of the
sufferers in the Massacre of St Bartholomew's Day,
1572. Carlo Maderna, born at Bissone, on the
Lago di Coma, 1556, originally a stucco worker,
was the architect who changed the plan of St
Peter's, Rome, from a Greek into a Latin cross.
Forsyth, in his " Remarks on Antiquities, Arts, and
Letters in Italy," speaking of St Peter's, says :
" Michael Angelo left it an unfinished monument
of his proud, towering, gigantic powers, and his
awful genius watched over his successors, till at last
a wretched plasterer came down from Come to break
the sacred unity of the master idea, and him we
must execrate for the Latin cross, the aisles, the
attic, and the front."

Mouldings. — The Romans generally formed
their mouldings from parts of the circle, while the
Greeks preferred the ellipse, or other sections of
the cone. ■ For Gothic mouldings there are no
set rules for setting out the curves or profiles,
these being generally drawn by hand, and char-
acterised by great freedom of form and position.
There are eight regular mouldings, the pro-
files of which, plain and enriched, are exhibited
in the annexed illustration (No. 209). Their
names are descriptive of their forms, which are adapted to the u.ses which they are intended
to serve. The ovolo and ogee, being strong at their extremities, are better fitted for supports ;
the cyma and cavetto, as they are weak in the extreme parts and terminate in a point, are well
adapted for coverings to shelter other members. The torus and astragal, shaped like ropes, are
intended to bind and strengthen the parts on which they are employed ; and the use of the fillet is
to separate, contrast, and strengthen the effect of other mouldings, to give a graceful turn to the
profile, and to prevent that confusion which would be occasioned by joining several convex members
together. The position of the scotia is universally below the level of the eye.

Scotia

C^fpuj i<r Cymutiwn

Talon or 0^c&

w^m

No. 209.— Mouldings, Pl.mx .and Enriched.

524 Plastering — Plain and Decorative.

An assemblage of essential parts and mouldings is termed a profile; and uw the choice,
disposition, and proportions of these mouldings depend the beautj-, light, and shade of the
composition. The most j^erfect profiles are such as consist of few mouldings, \aried both in form
and size. fitl>- applied with regard to their uses, and so distributed that the straight and cur\ed
ones succeed each other alternatelj'. In every composition in which mouldings are emplojed,
there ought to be some one predominant member to which all the others should appear subser\ lent,
and used either to support, strengthen, or protect it from injuries of the weather. Thus in
a cornice, for example, the corona predominates, the c>-ma and cavetto cover it, the ovolo and ogee

supjjort it.

Mouldings are either plain or enriched. When enriched, the ornaments should be cut into the
solid, and not applied to the surface, otherwise thej- would destroy the proportion and contour of
the moulding. This applies specially to classical mouldings.

The ancient scul]Jtors, in the execution of their architectural ornaments, aimed at a con-
ventional representation of the objects they chose to iinitate ; the acorns or eggs with which the
ovolo is commonly enriched are in the antiques cut round, and almost entirely detached, as are
likewise the beads on the astragal, but the leaves and flowers that enrich the cavetto, cyma, ogee,
•ind torus are kept flat, like the things the\' represent.

The ornaments of cornices should be made bold, so as to be distinguished at the proper
distance, while on the contrar\-, when the mouldings on the base of the column are to be enriched,
they should be more slightly exi)ressed, being near the eye — indeed, it would be impossible to
keep them free from dust were the}- indented b)' deep cavities.

A fillet is the smallest member in any composition of moulrlings. As alread)- mentioned, its
purpose is to separate two principal members, and it is used in all situations under such
circumstances. The corona is the flat projecting member of a cornice, and forms the principal
feature in all Grecian cornices. It should not be ornamented.

Bed moulds are those mouldings which occur between the corona and frieze, and are common
to all the orders. The facia is the principal member of an architrave. The abacus is the upper
member of the capital of a column whereon the architrave rests. The original intention in the use
of the abacus was to shelter and give breadth to the top of the column, and likewise to serve for
the better support of the entablature.

To Describe Roman Mouluixgs. — Illu.stration No. 210 elucidates the method of setting
out Roman mouldings. Fig. i is a quarter round, being a quarter circle ; A is the upper extremity,
and H the lower ; take the vertical line or height from U, and with that radius, from the intersection
at c, describe the arc .\ n, which will give the desired contour.

Fig. 2 is a "cavetto," being exactly the reverse of the last figure, and is described in a similar
way, with the exception that the centre c is formed on the e.xterior of the member as shown.

Fig. 3 is an ovolo, .\ being the upper extremity and li the lower ; take the vertical line or
height as a radius, and from B describe an arc ; from A, w ith the same radius, describe another arc,
cutting the former at^:,- then from c, with the same radius, describe the arc .\ i;, thus giving the
desired profile.

Fig. 4 is the cavetto, and is described in the same way as the last figure, with the exception
that the centre c is formed on the e.xterior as shown.

Fig. 5 is a "scotia," which projects equally at each extremity ; bisect the vertical line or height
from A to B, take half the height as a radius, and from the centre c describe the desired contour.

Fig. 6 is a "torus," which is a semicircle inserted on a vertical diameter as from A to li, and

Mouldings.

is described the same way as the last figure, with the exception that the centre c is formed on the
interior of the member as shown.

Fig. 7 is the " cj-ma-reversa," composed of two quadrants (or quarters of a circle^. To
describe this, join the projections A B, from these points form a square, and bisect it into four
squares as expressed by the dotted Hnes ; from c describe the convex arc, and from / describe the
concave arc, which completes the desired contour.

Fig. 8 is the " cyma-recta," being the re\erse of the " cyma-reversa," and is described in a
similar way.

Fig. 9 is a cyma-re\ersa that touches a straight line at the points of contrary flexure. To
describe this, join the projections a b by the straight line A B ; bisect A B in D ; draw the tangent
E D parallel to a line given in position ; through D draw cf perpendicular to ED; bisect A I) by
a perpendicular, ^c; from the intersection ^describe the arc from A to D; make V>h equal to Dc.
and from the point h describe the arc D B, which completes the cur\-e of contrary flexure A B D.

Fig-- 7. Fig. 8.

No. 210. — Seiting out Romas Mouldings.

Fi?. 10,

Fig. 10 is a "cyma-recta" that touches a straight line at the points of contrarj- flexure,
parallel to a given line in position. To describe this, join the points of projection A B ; bisect A B
in D, and draw the line D E parallel to the line given in position ; bisect A D by the line eg ; from c,
with the radius c D, describe the arc A D ; make n /i equal to D c. and from the point /i describe the
arc D B, which completes the desired contour.

To Describe the Greek Mouldings. — Illustration No. 211 elucidates the method of
describing Grecian mouldings. Fig. i is an ovolo. To describe this, two tangents being given,
as also their points of contact, let A E and E B be the tangents, A and B the points of contact ;
complete the parallelogram B E A F ; then produce B F to c; and make F c equal to F B ;
divide E A and F A each into the same number of equal parts ; through the points of division in
E A draw lines to K ; and draw lines through the corresponding points in F A to meet the
corresponding lines drawn to B ; and the intersections will be the curve of an ellipsis. The upper
part A D is a continuation of the same cur\e.

The same methods are used for Figures 2 and 3, but the following distinctions must be

526

Plasteyins — Plain and Decorative.

observed. In Fig. i the tangent K I! i.s regulated by taking the point E in the middle of AD.
In Fig. 2 the point E is one-third of An, and in Fig. 3 the point P: i.s one-third of A I) from A.
Then, according as the tangent is lower or higher, the curve will be quicker <>r flatter at the
same projection. The effect of this will be seen in the difference between Fig. i, the boldest, and
Fig. 3, the flattest.

When E H and A E are nearly equal, the moulding is the boldest of any taking D E at the
same height, but when the projection is very great or very small the moulding is extremely flat.

Fig. I.

rig. 2

Fig. 3.

Fig. 4,

No. 211.— Setti.ng out Grecia.n Mouldings.

Fig. 4. — The same data being given to describe the Grecian ovolo, supposing the point of contact
n to be the e.xtremity of one of the axes, draw H R at right angles or perpendicular to E B;
also Pf at right angles or perpendicular to B R for the other axis, so that the point P may be
above .\ ; then E B and Prwill be parallel. Td find the major axis, — From A, with the distance
H<r, d::icribe an arc cutting Ptat F; draw A F and produce it to meet BR and l; make cv equal
to .-v I ; then with c P half the major axis, and with c B half the minor axis, describe the curve
B .\ P o, which will give the desired curve. This is the most beautiful moulding of any. The
degree of curvature depends on the angle E B n, therefore when this angle is less the curvature
will be greater. With regard to the quirk at the point O, it will be more or less as the point A
is more or less distant from o. This also applies to the quirks at o in Figs, i, 2, and 3.

To Describe a Bead and Scotia.— The method of drawing a bead with fillets, and

two forms of scotia members, is elucidated
in illustration Xo. 212. The centre of the
bead is obtained from the angle of a square
equal in size to half the diameter of the
bead, as indicated by the thick "centre"
dot at an angle of the dotted lines. The

No. 212. — Setting oi't a Bead with Fillets and Scotias.

scotia is generally composed of elliptical
forms, or quadrants of the circle, differing
more or less from each other, as shown in
this illustration, by which means its projection may either be increased or diminished.

To describe the scotia on the right of the illustration, divide the height in three parts as
figured. Through the point at 2 draw a horizontal line parallel to the fillet line at 3, and equal to
one part, then draw a line perpendicular with the section line of the top fillet until it intersects with
the horizontal line, and on the point of intersection describe the quadrant, which forms the upper
part of the .scotia. Next set off one part on the other side as indicated by the circular dotted line,
then from the outward point of intersection describe the arc which completes the curve of the

The Orders of Architecture.

527

scotia. If a greater projection is required as shown by the scotia in the centre of the illustration,
divide the height into four parts, as figured, then proceed as before to form the quadrant, but to
increase the projection set off two parts on the outside of the horizontal line, and from the outer
point describe the arc as before. The dotted lines and thick points indicate the line, centres, and
radius for setting out the various parts of the members.

Grecian Doric.

Grecian Ionic.

Roman Ionic.

4ii'

Roman

Doric

c^-^^ — ■^=^

1 ' a

1 ■ 1

^Sji^g^

±.

No. 213. — COLU.MNS AMI KnTAHI.A I UREs

Xo. 214.— COI.IMNS ANl> ENTAHLATIIRES.

The Orders of Architectlre. — The three ancient orders are the Doric, Ionic, and
Corinthian. These are called the Grecian orders. The)- exhibit three distinct features of
composition, and are supposed to have been suggested by the diversitj- of character in the human
frame. The Romans had five, namelj-, the Tuscan, Doric, Ionic, Corinthian, and the Composite.
At what time the\- were invented or b\- whom perfected is at least doubtful.

Vitruvius, Scamozzi, \'ignola, and other architects vary more or less in the proportions of the

528

Plastcyiiig — Plain and Decorative

The proportions here given are those most

n use, and have the claim of

various orders,
preference.

The Grecian' Orders: The Doric. — This being the most ancient of all the orders, retains
more of the structure of the primitive hut in its form than any of the others, having triglyphs in the
frieze to represent the joists, and modules in the cornice to represent rafters, with inclined .sofifits to
express their direction in the originals which thej- imitated. In Greece the columns of this order
were placed on the floor without either pedestal or base. The best examples are only from 5 to 6
diameters high, which gives peculiar grandeur to the temples in which the Doric order is employed.
The flutes of the column are elliptical in form and twenty in number. The capital is about half a
diameter high, and is composed of a plain abacus, a flat ovolo of great projection, and a few small
fillets, called annulets which divide it from the shaft. The entablature is divided so that the
architra\e and frieze are each more than a third of its height, and the remainder is given to

the cornice. Illustration No. 213 shows
examples of the Grecian and Roman

columns and entablatures in the Doric

mJ" '^^(*\^^IK#^^li^*V^|3^^^^«^i ^ '^ order. This fine example of Grecian

Doric is from the Parthenon at Athens,
taken from the angle column of the
portico to show the pediment. For the
^ — sake of ready comparison, Grecian and
"~^ Roman examples of the same order are
given in one illustration.

The Ionic. — This order, being the
second of the Grecian orders, holds a
middle position, standing in equipoise
between the grave solidity of the Doric
and the elegant delicacy of the Cor-
inthian. This order is said to have been
invented by Ion, of lona, a province of
.Asia, where he erected a temple in this
order to Diana. The Grecian Ionic
column is not so high as the Roman
Ionic but the entablature is bolder and of fewer parts. The Ionic shaft usually has twenty-four
flutes. The distinguishing feature of the order is the capital, in which there is a considerable
difference between the Grecian and Roman examples. In the former the volutes appear only in
front and rear, and are placed flat on the column, leaving the ends in the form of part of a baluster.
This part is sometimes enriched. The Romans gave their Ionic capitals four diagonal volutes,
and hollowed out the sides of the abacus. Illustration Xo. 214 shows beautiful examples of Ionic
columns and entablatures.

The Corinthi.\N. — This, the third and last of the Grecian orders, admits of the highest degree
of enrichment, and pos.sesses at once an air of dignity and beauty. The invention of the graceful
capital of this order has the following romantic history. .A Corinthian maiden having died, her
lover placed on her tomb a basket containing trinkets in which she delighted when alive. He put
a tile on the basket to better shelter the contents. The basket was placed accidentally on the root
of an acanthus, which growing, shot it stems and foliage up and around the basket. Some of the

N'i. 215.— .\CANiHUS Mollis, the Suitoseh Ori<;ix of the
CoRiNTiMAX Capital.

The Roman Orders.

529

lea\es reaching the angles of the tile, were forced downwards, and by degrees curled into the form of
the volute. Callimachus, who for his great ingenuit>- and taste in sculpture was called bj- the
Athenians " Katatexnos," passing the tomb, saw the basket, tile, and the delicacy of the acanthus
leaves which grew around, and being pleased with the form and novelty of the combination, used it
as a model for the capital. The story is a pretty one, but must, we fear, be added to the long list of
popular but erroneous tradition. Illustration No. 215 depicts a view of the Acanthus mollis (the
supposed origin of the Corinthian capital), and is a good example for the young plasterer to first
draw and then model. The drawing and model should be made twice or even thrice the size
of the example. It will be easier to model it on a ground than on the round.

This beautiful order can but be \iewed with equal pleasure and admiration. It remains to this
day a perfect masterpiece of art. One of the most beautiful examples of Grecian capitals is shown
on illustration No. 216. This capital is one diameter and twenty-four parts in height. Its cone is a
perfect cylinder. This is banded by a row of water leaves, one-sixth of the whole height, and
another of acanthus, with flowered buttons attaching them to the cylinder.

The Roman Order.s : The Tuscan. — This order
is the simplest and most solid of all the orders. It is
composed of five parts, devoid of ornament, and of so
massive a construction that it seems capable of supporting
the heaviest burdens. This order is said to have been
invented by a native of Tuscan)-. It is the first order
according to the Roman sj-stem, and is nearly the same
as their Doric, divested of its triglyphs and mutules.
It is the most easil)- executed, and when employed
with judgment, has not onl\- grace, but by contrast gives
a beauty to the other orders. The methods of drawing an
order and setting out the heights and projections of the
mouldings are all taken from the standard of measure-
ment of each column, the standard being the diameter of
the shaft immediately above the base. Di\ide this into
a scale of sixt)- equal parts. This is done b}- first
dividing the diameter into two equal parts, called
"modules," then each of these into thirty equal parts, called "minutes." If necessarj-, each part
may be divided into sixt\- parts, called "seconds." The standard is therefore sixty seconds =
one part or minute; thirt}' minutes = one module; two modules = one diameter or si.xt\- parts.
The parts, base, shaft, and capital are termed the column. The mouldings above the capital are
termed the entablature. The parts below the base of the column are called the pedestal.
Illustration Xo. 217 shows the profile of the column and entablature of this order. The heights
of the column and entablature and their subdivisions are named and figured on the inside of the
profile, and the projections are figured on the outside of the profile ; the latter is taken from the line
of column. The column diminishes one-tenth to one-quarter of its diameter. All dimensions
correspond with the scale of minutes.

Ro>tAN DOKIC. — This order takes its name from the Dorians, a Grecian people in Asia. It is
next in strength to the Tuscan, and is distinguished b}- the channels and projecting inter\als in the
frieze, called " triglyphs." These are placed over the centres of the columns. The metopes and
mutules are exact squares, hence the intercolumnations are regulated by the trigljphs, which makes

Xo. 216.

GRECI.\N C.^riTAL KKO.M I HE CHORAGIC
MONIME.NT OF LysICRATES.

530

Plastering— Plain and Decorative.

it difficult to execute. The shaft of column is seven diameters hi-h. The base and capital are one
module each, making the column eight diameters high. The entablature is two diameters ; the two
" triglyphs " are each six modules wide. The metopes (or spaces between the triglyphs) are square.
and are often filled in with some ornament, generally representing the skeleton head of an ox. The
column is sometimes fluted, like the Grecian Doric. The Doric column and entablature is shown
on illustration No. 213.

tifi

t. WS^SS^^^SStZZZZZZZZ^ZZF

;3S3^5

L:.

ji 1 ii

mKX^UXUUM)<K A A A J.'^

No. 217. — The Tuscan Column and Kntablaiuke.

No. 21S. — Setting out an Ionic Pedestal for a Column.

RONfAX lOMC. — This order is somewhat similar to the Greek Ionic. The column is nine
diameters high, and diminishes two-fifteenths of its diameter. The entablature is from one-fourth
to one-fifth of the height of the column.

The drawing to scale and making a model about 2 feet or 3 feet in height of the column and

The Ionic Pedestal.

531

capital of this order is good instructi\e practice for the >-oung plasterer. The model maj- be kept
as a sample and for future reference when making a full-sized column. The construction of small
models to scale of the five orders would afford excellent practice for young plasterers in model-
making and modelling. The column and entablature of this order is shown with the Grecian
Ionic, on page 527. Plans, sections, and elevations of Ionic capitals are illustrated in Chapter X.

To Set out an Ionic Pedestal. — Illustration \o. 218 shows the elevation of an
Ionic pedestal with part of the column and its base. A is the list or fillet, B the upper torus, c
the scotia, D the lower torus, and E the plinth of the base of the column ; F is the cyma of the
cornice of the pedestal, G is the dado or die, H the base, and I the plinth of the base. The entabla-
ture of an order being a part proportionable to its column, and the pedestal an addition to both, it
is considered as a part of the column and entablature taken together ; therefore the height of the
column and entablature being divided into four equal parts, one of them is taken as the height of
the pedestal. This rule and the general divisions of the Ionic pedestal are obsened in each of the
five orders. The height of the column being divided into nine parts, one of them is the diameter
of it, as already mentioned. The height of the base of the column is equal to half the diameter of
the column. The projection of the base is one-third of the semi-diameter of the column, and
that determines the breadth of the die of the ^ ^^ M ^TTmTrnVyXl.l j;.r7.TTIlX:r.- -

pedestal. Di\ide the height of the pedestal into
four parts. One is the height of the plinth, half
the height of one of them is the height of the
cap, and one-third of one of them is the height
of the base of the pedestal. The projection of
the base is equal to its height, and the cap has
the same projection as the base. The upright
scale shows the heights and subdivisions of the
members of the \'arious parts of the pedestal
and base of the column, and the horizontal scale
shows the divisions of the members and their
projections. The method of drawing the various
members is shown and described in the para-
graph relating to mouldings.

The Corinthian. — This elegant order is distinguished by the superior height of the capital,
and being ornamented with lea\es, which support the \olutes, flowing to the angles and centre of
the abacus. The capital is in the form of a vase, the lower part being covered with two rows of
leaves, one above the other, eight in each row. 0\er these there is a third row of narrower leaves,
which cover the springing, and follow the curve of the eight volutes. The whole is crowned
with either a plain or an enriched abacus, concave on the four sides. The entablature is highlj-
enriched. Its architrave has usuall)- three fasciae of unequal height, and the frieze is frequently
decorated with foliage. The cornice has modillions and dentils. The column, including base, is
generalh- gh diameters high, and diminishes one-eighth part of its diameter. The entablature is
generall)- one-fifth of the height of the column. The height of the capital is sevent\- minutes, of
which the abacus should be a seventh part, the remaining portion being divided into three equal
parts ; the two lower give the height of the first and second rows of leaves, and the upper part
the space of the volutes.

Illustration \o. 219 shows the Corinthian capital of the three columns in the Campo Vaccino^

219.— CoRixTHi.AN Capital from the Temple of
lupiTER Stator, Rome.

532

Plastering — Plain and Decorative.

Corinthian.

Composite.

the supposed remains of the temple of Jupiter Stator. This is -jenerally allowed to be the
most perfect model of the Corinthian order amongst the antiques of Rome. Palladio, in his fourth
book, states that he never had seen any work better executed, or more delicately finished ; that the
parts are beautifully formed, well proportioned, and skilfully combined.

The Composite. — This order is so called because it is composed of the Ionic and Corinthian.

The capital is a vase covered with two rows
of acanthus leaves, and is distinguished from
that of the Corinthian by having the large
volutes and enriched ovolo of the Ionic
capital ; but in other respects it is similar,
both in proportions and mouldings. The
column, including the vase and capital, is
ten diameters high, and diminishes one-eighth
of its diameter. This order was first used
by the Romans in their triumphal arches.
Illustration No. 220 shows examples of the
columns and entablatures of the Corinthian
and Composite orders.

The Height of Columns. — The
height of a column in each order is measured
by its diameter immediately above the base.
The ancient Grecian Doric is from five to si.x
diameters in height. The Tuscan column,
seven diameters. The Roman Doric, eight
diameters. The Ionic, nine diameters. The
Corinthian, ten diameters. The Composite,
ten diameters. In the foregoing measure-
ments are included the capitals and bases,
which are esteemed parts of the column
with the shaft of which they are conjoined.

The Di.minution of Coi-UNrxs. — The
shafts of columns are diminished in diameter
as they rise. The ancient columns were
tapered from the base to the top in a straight
line, in imitation of trees, so that their shaft
was a frustum of the cone. In some e.xamples
there is a swelling in the middle. The
diminution at top is seldom less than one-
No. 220.— CoLu.MNs AND ENTABLATURES IN THE CoRiNTHiAN eighth, nor iTiore thai! onc-sixth of the
AND Composite Orders. inferior diameter of the column. The method

of setting out and constructing diminished columns is given in Chapter VI.

Proportion of Ent.\bl.\tures. — The height of the entablature in all the orders has in
general been made one-quarter of the height of the column. The total height thus obtained is in
all the orders, except the Doric, divided into ten parts, three of which are given to the architrave,
three to the frieze, and four to the cornice. But in the Doric order the whole heiirht should be

Impost and Architrave Mouldings.

^ "> ■>

divided into eight parts, and two given to the architrave, three to the frieze, and three to the cornice.
The above proportions are sometimes varied to suit different buildings.

Pilasters.— These are said to be a Roman invention. They bear an analogy to columns in

No. 221. — Doric I.Mrosr and
Archivolt Mouldings.

Xo. 222. — Ionic Impost and
Archivolt Mouldings.

No. 223. — Tuscan Impost and
Archivolt Mouldings.

their parts, and must have their bases, capitals, and entablatures the same height as those of
columns. When pilasters are used alone, as principals in the composition, they should be made to

project one-fourth of their diameter. This
gives great regularity to the returned parts
of the capitals, more particularly if the
pilasters should be Corinthian.

Impost and Architrave Mould-
ings. — The impost is the horizontal
moulding or capitals on the top of a
pilaster, pillar, pier, or abutment from
which an arch springs. In classical archi-
tecture the form varies in the several
orders. Sometimes the entablature of the
order serves for the impost of an arch.
The architrave or impost is the moulding
on the face of an arch, concentric with the
intrados, and supported by imposts. Im-
post and archivolt mouldings to arches for
classical work are set out to the scale of
the order employed. The annexed illustrations (Nos. 221, 222, 223, 224, and 225) show the
elevations and sections, with figured projections and heights of the members, of the imposts and
archivolts of the five orders. These mouldings are frequently enriched.

No. 224. — Corinthian Impost
and Archivolt Mouldings.

No. 225. — Composite I.mpost .and
Archivolt Mouldings.

534

Plastering — Plain and Decorative.

HalusTERS.— A baluster is a small pillar or pilaster serving to support a rail or cornice
generally ornamented with mouldings. A series of balusters is termed a balustrade, and is used for
surrounding balconies, terraces, &c. They are generall>- drawn to a scale of minutes. The annexed
illustration (No. 226) shows the elevations of the balusters appertaining to the five orders. Fig. i,
Composite. Fig. 2, Corinthian, with the base moulding n, and cornice or rail moulding R. Fig. 3,
Tuscan, square on plan. Fig. 4, Doric or Ionic. The top and bottom members are square on i^lan,
and the part between (called the body) is circular. This form of baluster is sometimes called
a double-bellied baluster. Fig. 5, Doric, another variety, is square on plan. Fig. 6, Corinthian,
ramped for steps, &c., with base and rail mouldings showing a half baluster butting against a pier

or die.

To Set out Balustrades — The method of .setting out the proportions of various kinds of
balusters and pedestals for balustrades is elucidated by the subjoined illustration (No. 227). Fig. i
shows the half elevation of a single-bellied baluster. The top and bottom plinths, P, P, are square on

-i

Kig. 1.

li-.

Fig- 3-

Fig. 4.

Fig- 5-

Fig. 6.

No. 226. — Balusters of the Five Ordkks, and Ramped Balustrade.

plan, and the moulded part between them (termed the body; is circular on plan. The height is
divided into eight parts, two of which go to the width, as shown by the upright scale. This scale is
subdivided to give the proportions of the various members, and to give the centres for the reversed
curves of the bellied part, the centres and radius for the latter part being indicated by the dotted
lines. Fig. 2 shows the elevation of half of a pedestal with a half baluster engaged on its flank or
inward side, also a complete baluster. This is a reduced size of Fig. i. The pedestal consists of
three parts — the base, B ; the die or bod\-, D; and the cap, C.

The height of bases and caps varies according to the style and position, but the proportions are
regulated by the height of the balustrade. The general proportion for balustrades is to divide the
whole given height into thirteen equal parts, and to make the height of the baluster eight of those
parts, the height of the base three, and that of the cornice or rail two. If it is required to make the
baluster less, the height may be divided into fourteen parts, giving eight to the baluster, four to the
base, and two to the cornice. One of the parts may be called a module, and being divided into nine

To Set 02 it Balustrades.

535

minutes, serves to determine the dimensions of the various members. In this example the height of
the cornice C is two parts, and the height of the base B four and three-fourths, as shown hy the scale
on the die of the pedestal. The distance between the balusters is one-half of their width, as shown
by the figures at the top of the base. The dotted lines show the centres of the bellied parts. The
foregoing remarks as to proportions, centres, &c., also apply to the following examples. Fig. 3
shows a baluster with the height divided into nine parts. Fig. 4 shows an enriched baluster with
the height divided into twelve parts. Fig. 5 shows a double-bellied baluster. Fig. 6 shows the
elevation of a half of a pedestal with an engaged half baluster on its flank, and a whole baluster.
This is a reduced size of Fig. 5. The sunk panel in the die, D, of the pedestal is proportioned
according to the parts figured on the side of the die.

7y ^. Fi^.5

Xo. 227. — Setti.ng out Balusters and Pedestals for Balustrades.

The distance between two balusters in a balustrade should not exceed half the diameter of the
baluster, measured in its thickest part, nor be less than one-third of it. The pedestals that support
the rail should be at a reasonable distance from each other, for if they be too frequent the balustrade
will have a heavy appearance, and if they be far asunder it will be weak. The most eligible distance
between them is when space is left in each inter\al for eight or nine whole balusters, besides the two
half ones engaged in the flanks of the pedestals. But as the disposition of the pedestals depends on
the situation of the piers, pilasters, or columns in the front— it being always deemed necessary to
place a pedestal directly o\er the middle of each of these— it frequentl)- happens that the intervals
are sufficient to contain sixteen or eighteen balusters. In this case each range may be divided into
two, or which is better, three intervals, by placing a die or two dies in the range, each flanked with
two half balusters. The breadth of these dies may be from two-thirds to three-quarters of the width

536 Plastering — Plain and Decorative.

of those of the princiixil pedestals. The rail and base mouldings are generall>- carried over and
under them in a straight line, without breaks.

Copying Mouldings. — Architects and students in building construction have devoted much
time to copying the mouldings of ancient and modern buildings. Of the several ways of doing
this the most simple of all is effected by inserting a piece of stiff paper in a loose joint, or by
appl)-ing the paper where a stone has been removed, and has left the edges sufficiently clear fot
the right lines to be traced by a pencil. This method is seldom available except in ruined build
ings, or where additions or alterations are to be made. Another way is by the use of a thiri
flexible lead tape, which is pressed ujion the moulding to be copied, and thence carefully removed,
and laid upon a sheet of paper. This retains the shajje it has taken, and it may be traced off with
a jaencil. This method is unreliable where perfect accuracy is imperative. The most complex-
mouldings can be copied with perfect accuracy by the aid of an ingenious instrument called the
" C\magraph," invented by Professor Willis. Another instrument, invented bj- Mr Henr\- Bash-
forth, |jossesses the remarkable advantage of cop\-ing mouldings, and also of reducing the copj- to
any desired scale. Mouldings may be copied and also reduced by geometric methods, as described
and illustrated on page 289. Another way is to copy by the eye alone. A practice of copying
mouldings by the eye is of great importance in acquiring a sound acquaintance with this very
interesting subject. After a little practice the eye becomes perfectly familiar with every kind and
variet)- of moulding by contemplating and comparing new examples with others previouslj- made.
In this way mouldings which are out of reach may be sketched very tolerably, especially if the
planes in which they lie be carefully formed. The planes in which the mouldings lie, such as the
ceiling and wall lines, and the relative proportions of the parts, must be carefully obser\-ed. B)'
adding the measurements of the projection and depth of the moulding and the main parts, any
inaccuracy of proportion may readily be rectified. Full-sized mouldings are easily reduced to any
desired scale by the use of the well-known instrument called the pentagraph. Mouldings within
reach may be quickly copied by means of squeezing. This is effected by first dusting the part to
be copied \\ith French chalk, and then pressing moist claj' or squeezing-wa.x on until thick
enough to be moved. Plaster should then be poured into the matrix thus formed, which yields a
copy of the original moulding. But the most ready and accurate method is that of taking a
plaster mould or template of the part to be copied, the form of which is accurateh- obtained,
though the convex and concave surfaces are of course reversed. B)' pouring plaster on the mould
an e.xact cop)- of the original moulding is obtained. The profile of the moulding may also be
easily obtained by laying the mould on a sheet of paper, and drawing the contour with a pencil.
The mould for this process is made in precisely the same way as used by plasterers to obtain
the profile of an old moulding when about to make a running mould for repairs or additions to
cornices. This is effected by brushing the part to be copied with oil or cla\' water, then laying
gauged plaster on the surface, so as to form a vertical body (from the ceiling to the wall lines)
about 2 inches wide, and in sufficient depth for the requisite strength. When the plaster is set the
mould is taken off If the moulding is undercut, the mould must be made at a cut end of the
moulding, so as to allow the mould to be pushed along and be extracted when it is clear of the
undercut parts. For large and intricate mouldings, or those deeplj- undercut, the mould must be
made in pieces similar to a plaster piece mould.

CHAPTER XXI.

TOOLS AND APPLIANCES.

Plasterers' Tools, Applianxes, and Plant — Labourers' Tools — Scaffolding — The Worshipful

Company of Plasterers — The Plasterers' Craft.

Plasterers' Tools. — Tools are necessary aids to all classes of workmen, and precisely as the tree
is known by its fruit, so is the workman known by his tools. The workman who shows little
interest in his tools takes little interest in his work. A good workman keeps a good set of tools.
Of course there are exceptions, as when a man through adversity has "parted with" some of his " kit."
There is a story of a man on the road, whose kit consisted of an old hawk, a hand-float, and the
handle of a stock-brush, ail carefully tied up in an old apron. Being successful in obtaining a job,
he went on the scaffold where there were several men at work, and being, twitted about his slender
and damaged stock of tools, he stuck his brush, or rather the handle of it, into a pail of water
among some other brushes, saying that his brush (the handle) looked as well as the best brush in
the pail. It is surprising how little interest is taken by some men in a good and full kit of tools.
They will either borrow, or plod and blunder on for years with a few old implements, until they are
outpaced either in time or quality, or both, by more thoughtful and careful men, who have not only
good and clean tools, but also a proper tool for each section of the work. To the \-oung and
persevering plasterer I would suggest a quotation from Shakespeare — " Take you to your tools."

Among the plasterers' relics found by Dr Flinders Petrie at Kahun, in Egypt, were two hand-
floats. Having seen them at the University College, London, where they are now located, I took
their measurements, which are as follows: — One is 3f inches long and i| inches wide, rounded at
both ends, and slightly convex on the sole. The handle extends all the length of the sole as in our
modern panel-floats, and the whole float is cut in the solid. The other is longer, and has evidenth'
been used for the rough coat. The sole projects beyond the handle, more at one end than at the
other, somewhat like our modern skimming hand-floats. This is also cut out of a solid block. Both
of these were smeared with mud plaster, just as their owner had left them. These are the oldest
known plaster tools in the world, and were used for plastering B.C. 2500.

Plate LI I. illustrates plasterers' tools, plant, and appliances. .\ is the stand, 15 the gauge
board, and C the platform, nailed on the bottom rail of the stand. No. i is a laying trowel with
a double " shank." 2. Laying trowel with a single " shank." 3. Panel trowel. 4. Margin trowel.
5. Gauging trowel. 6. Small gauging trowel. 7. Large gauging trowel. 8. A hawk. 9. Ordinary
hand-float. 10. Cross-grained hand-float. 11. Skimming-float. 12. Joint rule with stock.
13. Small joint rule with stock. 14. Small joint rule without stock. 15. Moulding knife. 16.
Plaster chisel. 17. Level. 18. Chalk line and reel. 19. Fine drag. 20. Coarse drag. 21. Scratch
drag. 22. Brad-awl. 23. Tool-brush. 24. Large tool-brush. 25. Duster. 26. Flat wide stock-brush.
27. Four-tufted stock-brush. 28. Hand-float for cement work. 29. Panel-float. 30. Fining-float
with round end. 31. P"ining-float with splayed end. 32. \\'ater pot. 33. Plaster plane. 34. Lath
hammer. 35. Fine hand sieve. 36. Gauge pot. 37. Mitre box. 38. Square. 39. Compasses.

538 P/asfcriiig — Plain and Decorative.

40. Plumb rule and bob. 41 and 41 A. Scratches. 42. Combined square, triangle, and level. 43. Broom.
44. Pail. 45. Tool bag. 46. Water measure. 47. Tool box. 48. Darby. 49. Plaster box stand.
50. Plaster box. 51. Angle-float. 52. Concrete rule. 53. Gauge rule. 54. Nippers. 55. Traversing
rule. 56. Feather edge rule. 57. Saw.

Banker. — A banker is used for gauging large quantities of material, the gauging being done
with shovels. They were in general use when hawk-boys did all the gauging for plasterers.
Bankers are made about 5 feet long and 4 feet wide, with side boards, 6 inches high, on two
sides and on end.

Brushes. — Good brushes are formed with hog bristles nailed or bound on wood handles with
string, copper wire, or metal bands. Cheap brushes are formed with grass fibre, &c. The principal
one is the stock-brush, which varies slightly in size and form. In some districts a brush having
three or four tufts tied with string or wire is used ; in other districts a flat wide brush bound with
leather and nailed is preferred. Tool or sash brushes are used for mitring, stopping, and general
shopwork. Fibrous brushes are generally home made. The hair is about 4 inches long, and tied
on a handle about 6 inches long, li inches wide, and i inch thick. After the string is tied, it is
.saturated with hot glue. A hot iron is afterwards passed over the glue to bind the hair together.
It is customary for employers to supply stock-brushes (for whitewashing only) and all shop brushes,
the men finding stock-brushes and tool and water brushes for building work.

Brooms. — The.se are made of split whalebone or metal wires, and are used for keying plaster
work, sweeping scaffolds, paving works, &c. They are supplied l)y the emplo)^ers.

Calipers. — A caliper is somewhat similar to compasses, but has inverted arched legs.
It is used for taking the diameter of convex or concave bodies. Hardwood calipers are made
with a mo\able centre, so that the proportions between the points can be altered. They are used
for enlarging and reducing. Large calipers and compasses are found b}- the employers.

Co.\lP.\ss. — The compass is a two-legged instrument for describing arcs or circles, &c.

CllALK-LlNE. — This is a long fine cord fixed on a reel. It is used for forming long lines, &c.

Cr.XDLE. — This is a wood frame made to any desired concave curve, and then lathed and
plastered. It is used as a ground in forming, running, or moulding circular work. If the curve is
convex, it is called a " saddle."

Drags. — These are generally made of thin steel plate, with toothed edges. They are made
in various sizes and forms. They are used for dragging surfaces to make them straight or smooth,
also to make surfaces rough to give a key for another coat of material. A piece of an old tenon
saw about 6 inches long makes a handy drag. A scratch drag is used for keying the back of cast
work before the material is set. A useful size is 4 inches long and 2 inches wide. The teeth are
made about \ inch wide, \ inch deep, and \ inch apart. A smaller set of teeth are made on the
ends for scratching narrow parts. The teeth should be undercut so as to afford a better key.

Files and Rasps. — The.se are made of steel, and are used for finishing running mould plates,
and for cleaning up plaster and carton-pierre. Coarse rasps are used for fining concrete work.
It is usual for employers to supjjly files and rasps.

Floats and Rules. — There is quite a family of floating rules and other rules used for plaster
work, all varying in size and form, according to their special purposes. They should be made of
well -seasoned pine, free from knots.

Angle-Float. — This is from 2 to 3 feet long, 3 to 4 inches wide on each face. It is used
for forming internal angles true and square. This float is now unfortunately obsolete.

Concrete Floating Rule.— This is similar to a parallel rule, and is about I inch thick.

Plasterers Appliances. 539

6 inches wide, and in various lengths. Two hand holes are cut on the float to give more power
to the worker when floating concrete, which is mostly done by beating with the edge of the
floating rule.

Darbv. — This has a blade or sole from 3 feet 6 inches to 4 feet long, 4 to 5 inches wide,
and i to I inch thick. Two handles, each about 5 inches long and 2 inches in diameter, are
nailed or screwed on the back of the blade at about one-fourth of the length from each end. The
darby is used for floating bays between screeds on walls and ceilings, and in some instances for
floating setting stuff to a fair surface, before hand-floating and trowelling. In Scotland it is called a
" slack-float." Darbies are generally supplied by employers.

Fe.\TIIER-Edge. — This is of any desired size, but is generally about 5 feet long, 5 inches wide,
and I inch thick. One end is cut to an angle of 45 ; and one side is splayed pntil the edge is about
iV inch thick. It is used for working and cleaning out angles, &c.

Flo.\ting Rule. — This is the principal rule for floating screeds and flanking in baj's. They
vary in size from 8 to 20 feet in length, 4 to 7 inches in width, and \\ to 2i inches in thickness.
The back edge is tapered towards the ends. The taper not only decreases the weight, but gives a
counterpoise at the middle, thus giving more power to the worker. They are used for forming
screeds and ruling off, and forming fair surfaces between screeds.

Gauge Rules. — These are similar to straight-edges. A double gauge rule has a sinking cut
to the desired depth at each end. It is used for forming sunk surfaces. A single gauge has a
sinking at one end. It is used for forming raised surfaces, such as the plinth of a skirting.

Grooved Rule. — Considerable physical strength is required when working a long floating
rule, and in some positions it is difficult to hold, and apt to slip out of the hands or cramp the
fingers. To prevent these evils, I ha\e introduced an improved rule, called a " grooved rule." This
is made like a floating rule, but ha\ing a groove on each side. The grooves are made about 2 inches
wide, i inch deep, and i inch from the back edge. The size and position of the grooves can be
regulated according to the size of the rule and the requirements of the worker. The grooves give
a better grip, and more power and freedom when working. It also decreases the weight of the rule,
and if this decrease is only i lb., it will make a considerable total weight for the worker to
carry or move about during an eight-hours' day. Two holes, each about i inch in diameter, are
formed in the sides. These prevent the rule from warping, and are handy for hanging it up when
not in use. The plan and section of a grooved rule is shown on illustration No. 34 (page 159}.

P.\rallel Rules. — These are of various sizes. A useful one is 9 feet long, 6 inches wide,
and I inch thick. They are used for levelling and for setting out parallel lines.

Levelling Rule. — This is made by nailing a wood fillet on a long parallel rule. On this
fillet a level is placed to act as a guide when levelling ceilings, &c. The elevation of a levelling
rule is shown at Fig. 2, illustration 34 (page 159).

Plumb Rule. — This is similar to a parallel rule, but has a centre line, and an opening at one
end to allow the lead-bob to work. It is used to plumb walls, &c.

Running Rules. — (In Scotland they are called "rods.") These are made in long lengths,
and about 2\ inches wide, and \ inch thick, and are planed on all sides and edges. The}' are used
as guides or bearings for running moulds, when running mouldings. They are also used for fences
and for a multitude of purposes for scaffold and shop work.

Straight-Edge. — This, as its name implies, is any form of rule that has a straight edge. It
is used for testing the truth or straightness of walls or other surfaces.

Screed Rules. — These are made to any desired size, but are generally 2i inches wide, i inch

540 JViJsfcriiig — f/diii and Decorative.

thick, and in long lengths which are cut as desired. Thcj- are used as screeds when la\i'ng
concrete, also where a square edge or a given thickness is desired in plaster work.

Thickness Rule. — These are similar to screed rules, and are used for a given thickness.

TK.WERSlNt.; Rule. — This is simply a small floating rule about 6 feet long. It is used for
forming .screeds of gauged putty, or setting stuff, for running mouldings on. This rule is called a
"justing rule" in Scotland, and a "sweeting rule" in the North of England. Employers find all
these floats and rules.

Hand-Flo.\ts. — There is quite a host of hand-floats used for plastering purposes. With the
exception of |)anel and mastic floats, which are made of hard woods, all the other kinds arc made of
yellow pine, and there are none .so well made, or at least so suitable to the worker, as those made by
himself The float most generally used is the hand-float. It is about \o\ inches long, 4^ inches
wide, and \ inch thick. The cross-grained float is about 1 1 inches long, 4^ inches wide, and i inch
thick. The sole is cut with the grain crosswa)-s, in order that the sides may cut the work freel}' and
last longer. On the upper surface a dovetailed groove is cut, measuring \ inch deep, 2 inches
wide at one end, and tapering to i \ inches wide at the other. A hardwood bar is made to fit the
groove, and on the bar the handle is fi.xed with screws. The bar strengthens and pre\ents the sole
from warping. Cross-grained floats arc used for scouring the setting coat of good three-coat work,
and for making angles .square and clean. Float soles soon wear thin, and it is desirable to keep a
few in stock that they may get well sea.soned.

Skimming-Flo.-VT. — This is from 12 to 14 inches long, 4! inches wide, and \ inch thick. It is
used for laying .setting stuff and cements.

P.\Xi:L-Flo.\T. — This is made of beech, pear tree, or other hard light-coloured wood, which will
not stain the white plastic material. The soles are about 6 inches long, 3 inches w^ide, and \ inch
thick, having the top edges splayed. It is used for lajing and smoothing gauged stuff in panels,
al.so for mastic.

Finixi;-FL0ATS are of various sizes, varj-ing from 3 to 6 inches long, from i to 3 inches wide,
and from \ to \ inch thick. They are used for fining Portland cement mitres, cornices, panels, &c.,
and where larger floats cannot be u.sed. Workmen find all wood hand-floats.

Iron-Floats are usually cast in one piece. The>- are used for ramming and beating concrete.

G.\UC.E. — This is a wood measure cut to a given length. It is used for setting out spaces and
marks. If there are a number of equi-distant marks required, a gauge will be found more accurate
and expeditious than a foot-rule.

Gauge Boards and St.\XCES. — These are used as grounds for gauging plastic materials.
The boards are generally made about 3 feet 6 inches long, 3 feet 3 inches wide, and \ inch thick.
Two cross cleats are nailed on the back. A diagonal cleat fixed between the cross ones prevents
the board from warping. Stances are used to support the boards. They are made with four legs,
each about 2 feet 6 inches high. A top rail is fixed on all sides and flush with the leg tops ; another
rail is fixed about 6 inches from the bottom. In good stances the lower rail is boarded over, to
form a platform (as shown at c on Plate LI I.) to contain tools, &c., when not in use.

Gauging boards for concrete are made about 9 feet square, aufl i inch thick, with strong cross
cleats. They are made in two halves, to allow them to be easily moved. The cross cleats ]Droject
about 6 inches on one side of each half, so that on being laid down the cleats will fit together and
keep the halves in position. The hahes are sometimes held together with hinges.

Gouges and Chisels. — These are similar to those of wood carvers, and are used for carving,
cutting, and cleaning up plaster, cement, and carton-pierre, &c.

Plasterers Plant. 54 1

Groovers and Rollers. — Groovers are of various lengths, the most useful being 2 feet
6 inches long, 4 inches w ide, and i inch thick. One edge is splayed on both sides into the shape of
a flat V. They are made of beech or other tough wood, and some have metal edges. They are u.sed
for forming grooves in concrete surfaces. Rollers are made of brass, and have a series of projecting
pins. The usual size is about 8 inches long and 4 inches diameter. They are used for indenting
concrete surfaces to give a better foothold. Jointers are small rollers about 2 inches long, with a
rim projecting about \ inch on one side, which forms an indent to represent a joint. The roller is
made plain or corrugated, as desired. The latter forms a series of marks (similar to chisel-worked
stone) on the edges of the concrete slab. The best kinds of rollers, jointers, and groovers are made
by A. Gilchrist, of Glasgow. Groovers and jointers being plant, are found by employers.

Hammers. — A plasterer's hammer is made with a steel head, one end being in the form of a
hatchet blade with a slot for e.xtracting nails, and the other, or driving end, is indented to prevent
slipping. A wood handle is fixed into the shoulder of the head. It is used for lathing and general
scaffold work. A mounter's hammer, for driving French nails and needle points when mounting
composition, carton-pierre, &c., is similar to an upholsterer's hammer. A hammer with a flat round
head and a short handle is used for piece moulding. Knapping hammers, as used for breaking stones,
are employed for breaking foundation materials for concrete. Knapping hammers are supplied by
employers ; lathing, mounting, and moulding hammers by the workmen.

Hawk. — This is usually made of pine. The board (on which the stuff" is held) is from 1 1
inches to \2 inches square, and about j inch thick. The four sides of the back are splayed about 4
inches wide, so as to leave the edges about f inch thick. A dovetailed groove about % inch deep,
3i inches wide, and diminishing in width about j inch, is made in the centre of the board, and
across the grain of the wood. A bar is made to fit the groove. Though usually made of pine, in
some districts beech or other hard woods are used for the bars to give greater strength. The handle
is made of pine, and about 5 inches long and \\ inches in diameter. Sometimes it is turned,
having a slight swell in the centre, and a rounded knob at the end. This shape is not so apt to slip
from the hand as a straight handle would be. It is fixed on the bar with one thick screw in the
centre, which allows the handle to be taken off at pleasure. Another way is to fix it permanently
with three fine screws, the heads flush with the bar, so that the bar and handle can be withdrawn in
one piece. A hardwood bar, with the handle fi.xed in this wa\-, will last for three or four boards.
A common but clumsy way is to fi.x the board, bar, and handle in one piece, by driving two or three
nails through the face of the boards into the bar and handle. There is a modern hawk, which is
called "the hinged hawk." The board is made with the groove as first described. A line is then
made longitudinally through the centre of the groove, and cut with a fine saw, thus di\iding the
boards into halves. A small brass hinge is fixed about i inch from the end and flush with the
surface of the groove, and another hinge is also fi.xed at the other end of the groove, thus keeping
the halves together, and allowing the board to be doubled up when required for packing. The
bar and the handle fi.xed together are pushed into the groove, which prevents the board from
collapsing, and keeps the hawk rigid. A leather or rubber collar fixed on the bar will prevent the
hard wood or damp affecting the joints of the forefinger and thumb. American hawks are from 12
to 14 inches square, and in some instances the board part is made of sheet iron, with a wood handle.
Hawks should be light, strong, and damp-proof They are used for holding stuff", and for gauging
small portions of stuff". Hawks, being tools, are found by the workmen.

Hod. — The hod, like many other tools, varies in size and form, according to the district in
which it is used. The London hod is the smallest, the American one the largest, while the Scotch

542 Plastcri)ig — Plain and Decorative.

one gives the happy medium in size. The box of the London hod measures about i6 inches long,
with sides 9 inches deep, and will hold about two-thirds of a cubic foot of mortar, or about 40 hods
to the cubic yard. The box of the American hod is about 2 feet 4 inches long, and has sides
I foot deep. That of the Scotch hod is about i foot 10 inches long, and has sides 11 inches deep.
The shank varies in length from 3 feet 3 inches to 3 feet 9 inches. It is fixed a little in front of
the centre of the box, and a flat round block is fixed behind it, and an angle stay in front. A hod
this size will hold, when heaped, i cubic foot of mortar, weighing 1 10 lbs.; therefore if the weight
of the hod (from 8 to 14 lbs.) is added, the labourer carries over i cwt. in each load of coarse
stuff. One cubic foot of coarse stuff is allowed to this size of hod, which equals 27 hods to the
cubic yard. Hods are labourers' tools, but in some districts they are found by employers.

Joint Rules.— Wood joint rules made of hard wood, such as pear-tree and boxwood, were
used for mitring before steel plates were introduced. Where long mitres have to be done, joint
rules made of pitch pine, feathered on one side, and one end cut to an angle of 75°, and seasoned
with linseed oil, are best for the purpose. They work clean and smooth. The joint rules now in
use are made of sheet steel in various lengths, from 3 to 4 inches wide, according to the length, and
about i inch thick ; one end is cut to an angle of about 30° ; the acute angle and one side
being splayed about one-third of the width of the rule, leaving it moderately sharp, with a
straight-edge. Scotch joint rules are made with a thinner plate let in about i \ inches to a piece
of hard wood (called a " stock "), generally of mahogany or oak, about 3 inches wide, and % inch
thick. The stock and plate are fixed together b}- inserting two or more rivets through the wood
and steel. This wood backing or "stock" stiffens the plate, is more agreeable to the touch, and is
not so liable to cramj) the fingers as when using a thin, cold, steel joint rule.

Knivks. — Building knife blades are about 6 inches long, trimming knives from 4 to 7 inches
long. A small knife about 3 inches long, ground on both edges to a sharp point, is useful for
trimming the curves and eyelets of small perforated ornaments. A canvas knife is thin and broad,
with a square end, similar to a cobbler's knife. Moulding knives are from 9 to 15 inches long.
Composition knives are about iS inches long, with a handle at each end.

L.\RRV. — A larry (also called a drag) is a three or four pronged rake with a handle from
6 to 9 feet long. It is used for mixing hair with coarse stuff, and knocking it up for use. A rake
is similar to the larry, but has a plain blade instead of the prongs. It is used for making setting
stuff, &c.

Level. — A spirit level is the companion to the square and compass. It is, as its name
implies, for le\elling. Levels are found by the workmen.

Mitring Tools. — The annexed illustration (No. 228) .shows a set of mitring tools, or
"small tools," as they are often termed. Small tools are made of various sizes and shapes out
of wrought iron or steel. They are used for mitring, moulding, cleaning out, and stopping
ornaments. The principal one has a leaf or spoon-shaped blade at one end, and an oblong square
blade at the other. The\- \ary in size from 7 to 11 inches long. The barrels should be octagonal
in section and thick at the centre. A round barrel is apt to turn or slip, and a small one to
cramp the fingers. Xo. i is a small tool having a square end and a leaf end. This is used for
mitring and stopping. No. 2 is a small spade tool having one end square and the other with a
trowel or spade-shaped end. This is generally u.sed for laying and pressing the gauged stuff on the
back of the cast, and is useful for a variety of purposes. No. 3 is a large mitring tool having a
leaf end and a square end. No. 4 is another form of mitring tool having a pointed leaf end and
a round leaf end. This is used for mitring, bedding ornaments, and cleaning out hollow members.

Mitring Tools.

543

No. 5 is a double square-ended small tool used for a variety of purposes. A double square end
small tool with one blade i^ inches wide and 2 inches long, and the other \ inch wide and
I ^ inches long, is useful for laying and finishing narrow spaces, and cleaning out when fixing blocks,
also for work where the margin trowel is too large. In former times bone tools hollowed out
to fit different sized beads were greatly in use for forming beads when mitring. A few tools with
the blade end straight and the other curved, having the edges serrated, are useful for working
circular work, or where the plaster is full. They are commonly called " scratch tools."

Scratch Tools. — Illustration No. 229 shows the form of various scratch tools. No. i is
a gouge tool generally used for carving mitres of mouldings and cleaning up enrichments.
Various forms and sizes of gouges are used in shop work. No. 2 is a double-ended scratch tool
curved on section. This is used for working down mitres of enrichments, also circular plaster
work. This bent square-ended tool will be found very useful for cleaning up models as well as

No. 22S. — Mitring and Stopping Tools.

for modelling. This form of tool is also useful for modelling cement or plaster work in situ.
Nos. 3, 4, and 5 are various forms of scratch tools used for Gothic and circular mitres, and will
be found very useful in shop work. No. 6 is a stopping tool having a leaf end and a spear end.
One edge of the spear end is serrated, and the other left plain. This is a useful tool for many
shop and building purposes.

Pails. — The.se are generally made of galvanised sheet iron, and hold about 4 gallons.
Wood pails to hold 3 gallons are used in some districts. Putty pails have an extra handle on
the sides. It was formerly the custom in London for the men to find pails ; now all employers
find them.

Pinchers or Nippers. — These are made of steel. They are used for extracting nails and
twisting wire, &c. These are found by the workmen.

Radius Rod. — This is a wood or metal rod on which a running mould is fixed at one end
and a hole made, or a metal plate fixed at the other. The hole or plate is made to fit the centre

544

Plastering — Plain and Decorative.

pivot. It is used for runnini; circular moukliiiijs. In ScollaiKi it is called a "gig-slick,"' and in
some districts a " trainer."

Plane. — Planes are useful for lexeiling down and smoothing piaster surfaces. The iron or
blade should be toothed. Toothing or veneer planes are generally used for plaster and scagliola
work. Planes are supplied b)' the employers.

S.UV.^. — Plasterers' saws are about l8 inches long. They are used for cutting running rules,
and mouldings, &c. A fine-toothed saw is best for cutting fibrous ])laster. It is customary for
emplo)-ers to find saws for fibrous plaster and shop work.

Sc.VFKOLDS. — The.se are temporary structures of timber, clad with boards, for the men to work
on, and to place materials and tools on. In Scotland plasterers generally erect their own scaffolds.
For ordinary sized rooms the uprights are called " slipheads." Thry have a slot at the top to
recei\-e the needle or transom. The scaffold is clad with battens 7 inches wide and 2\ inches
thick. They are jjlacrd about 7 inches apart, and it is surprising how few accidents occur in

Xo. 229.— Scratch Tools.

working on this kind of open platform. In many parts of England they are made by regular
scaffolders who are employed by the general contractor. The transoms are tied on poles with
cords, and then the scaffold clad with boards eacli 9 inches wide and i^ inches thick. The)' are
laid close together, or nearly so. A close scaffold is safer than an open one.

SCR.VTCII. — The scratch is generally cut out of a pine board, about 14 inches long, 7 inches
wide, and A inch thick. The teeth are cut about 3 inches long, and the points about i| inches apart.
A simple but most effective scratch is made by fixing four laths together and then tapering the
points. Good and durable scratches are made out of thin metal plates, or strong wires in.serted
into a wood handle. It is customary for the employer to supply scratches.

Screen. — A screen is an ujiright sieve about 6 feet long and 3 feet wide, with sides 6 inches
deep. It is fixed at an angle of about 45°. It is used for .screening lime and sand. The materials
are dashed against the wires, when the finer parts pass through, leaving the coarser parts on the
inside. Screens being plant, are supjjlied by employers.

Plaster Snl-\ll Tools. — These tools are somewhat similar to mitring tools, and are

Plasterers Plant and Labourers' Tools.

545

used for shop work. A few extra shapes are required for cleaning up originals. Brass
small tools are useful for cleaning up plaster, and are generally made by the user. They are made
out of brass rod about \ inch thick. The rod is cut a little longer than the length of tool, to
allow for cutting off the split ends, which generally happen while being beaten. The ends are
beaten out flat, and then filed to the desired shape. The centre or barrel is filed so as to form
an octagon, to prevent it turning round in the fingers while being used. Waxed strings tied round
the barrel keep it steady while being worked, and also form a soft easy hold. Illustration No. 230
shows a set of plaster or shop small tools used for working plaster. They are made principally
in Paris, where they are extensively used for general shop work.

Sieves or Riddles. — These are made in various sizes and fineness, according to the material
and purpose. They are used for running and riddling lime, and washing sand. A riddle-rest is
used in some districts to carry the weight of the riddle and lime. It is rapidly moved backwards
and forwards by one man while another fills it, and as the lime forms in heaps, they move back a
little, and so on until finished. Putty sieves are made with a fine wire or hair mesh, fixed on a
round or square wooden frame. Two handles are fixed on the frames. " Punching sieves" are used
in some districts for making setting
stuff. They are constructed with a
wooden frame about 2 feet square
and 7 inches deep, on which a
strong fine steel wire mesh is fixed.
A wooden punch, somewhat like a
large hand-float, to admit of both
hands, is used for punching the
putty and sand through the mesh
into a tub on which the sieve is
placed.

Squares. — These are made
of wood or iron, and of various
sizes. A handy size is one about

I foot on each square edge. The\' are triangular in form, and the 45' angle is useful for giving
mitre joints. They are sometimes made with a level, or a small plumb-bob, or with both, and are
useful in forming small works plumb and level. A small one, about 6 inches, is useful for return
mitres, &c. Wood squares, about 3 feet, are required for large work on ceilings, shop, and flooring
work. It is customar\- for employers to find large squares, and the men small ones.

Templ.\tes. — These are circular running rules and screeds. They are cut out of one or more
pine boards to the desired curve. Plaster templates are used for running clay profiles, &c.

Tool Box. — This is for keeping plasterers' tools, overalls, cap, apron, &c., clean and safe.
They are usually made about 18 inches long, 14 inches wide, and 12 inches deep (all inside measure-
ments). A movable tray 5 inches wide and 2\ inches deep, placed on runners inside the box, is useful
for holding small tools. The box is usually carried by the aid of a strap fixed to the handles. American
cloth bags are also used for keeping tools. In some districts the tools are simply tied up in an apron.

Trowels. — Trowels are of various shapes and sizes, each one having its own special use.
The most important of its kind, and constantly used tool for plaster work, is the " laying trowel."
Tyzack, of London, is a noted maker of plasterers' tools, his trowels being in general use throughout
the United Kingdom.

Xo. 230. — Pl.vster Small Tools.

546 Plastering— Plain and Decorative.

Lavim; Tkowels are about lol inches long and 5 inches wide. The plates arc made of the
best steel, light and flexible. The " shank " is riveted on to the plate with three, and sometimes
four rivets. Some trowels have two shanks (without fangs), one at each end, made with a flat
round head with a countersunk hole, to receive screws, or a long rivet.

PoLlsillNi; Trowels are half-worn la)'ing trowels. The edges should always be straight and
parallel, or nearly so. Parallel edges work truer than tapered edges.

The Margin Trowel is similar to a gauging trowel, but the edges of the blade are parallel,
and the end cut square. The blade is about 3 A inches long and 2i inches wide. The handle is
shorter than that of a gauging trowel. It is used for laying and polishing margins, styles, or
spaces where a larger implement could not be employed.

The Angle Trowel is a novel tool for finishing internal angles. It was invented by the
late R. Millar, my brother. It is similar in form to a margin trowel, but having about i inch of
the two side edges of the blade turned up at right angles to the blade, and perfectly square. The
points of the turned up sides are cut to an angle of 45 \ R. Millar was well known in the trade,
and noted for his large and varied collection of tools, which numbered nearly five hundred.

The P.\NEL Trowel is similar to a laying trowel, but the blade is thin and springy, and is
about 5 inches long and 3 inches broad. The handle is slightly shorter than that of a laying
trowel, to allow it to be easily worked in small and deep panels. A good panel trowel can be made
out of an old laying trowel. It is used for setting small panels.

Gal'c.ini; Trowels are of various sizes, but the most u.seful is one, the blade of which is
about 6 inches long and 3 inches wide at the heel or handle end, and tapering to a narrow point
at the other end. The shank and blade are sometimes made separately, and riveted together, but
more often they are forged in one piece. The wooden handle is bored to receive the fang of the
shank, and partly filled with powdered resin and plaster. The fang is made hot and pushed in,
and the heat melting the resin, it forms the plaster into a strong cement, securing the fang and
handle together. Gauging trowels are used for gauging small portions of stuff on the gauge
board, or on the hawk, and for laying stuff on mouldings, mitres, &c.

The Laving Gauging Trowel is nearly of the same .shaj^e, but much larger than the ordinary
gauging trowel. The blade is from 7 to 9 inches long, and from 3 to 3! inches wide at the
heel end, and tapering until from i^ to 2 inches wide at the point. It is used for laying gauged
stuff on large mouldings and for bedding large plantings. The small gauging trowel is generally
an old one which has been worn small, and ground to a sharp point. It is used for stopping small
holes, scraping and cleaning rules, &c. The handles of gauging trowels are generally made of ash,
with deep brass ferrules. They were formerly made of mahogany or ebony.

Tubs. — These vary in size according to requirements. They are used for holding water,
washing sand, slaking lime, &c. An old spirit cask cut in half, makes good tubs.

Plasterers' Plant, Labourers' Tools, and Scaffolding. — The annexed illustration
(No. 231) shows plasterers' plant and labourers' tools. No. i. Scaffold trestle, also used as a hod-
stand, as shown. 2. The hod. 3. Putty jDail. 4. Shovel. 5. Larrj- for coarse stuff. 6. Water-tub.
7. Riddle-rest. 8. Putty sieve. 9. Sand-.screen. 10. Sliphead. 1 1. Putty slack box. 12. Banker.
13. Putt)- rake. 14. Hawk-boy's server. This tool is now obsolete, and is only given as a relic of
the past.

Cleaning Plasterers' Small Tools. — Plasterers generally clean their small tools by rub-
bing them with a piece of wood dipped into setting stuff or brick dust. This keeps them bright,
but it wears them out far more than the working with them. The rubbing also scratches the

The Worshipful Company of Plasterers.

547

surface, and spoils the edges. They should always be cleaned, when done with for the day, or when
the job in hand is finished, \>y wiping them thoroughly dry. Rust destroys them, and it takes twice
as much labour to get them bright again. If the tools are always dried as soon as done with, they
will keep a better surface. Small shop tools for cleaning up with, can be kept clean and smooth,
and they will have a nice dark blue polish, by simply scraping or rubbing the plaster or clay off
with the back of a knife. The barrels or thick centre parts of all small tools should be kept
clean in some simple way. Some plasterers temper and get a dark blue on their small tools by
holding them over a red-hot iron until blue, then dipping them into linseed oil. If the tools are
properly made at first, they require no tempering. Many industrious plasterers make their own
small tools out of old files, or fencing foils. A beautiful deep black polish can be given to all small
tools, whether bought or home made, by boiling i part of sulphur in lo parts of oil of turpentine.

No. 231. — Plastekers' Plant and Labourers' Tools.

which produces a brown sulphurous oil. The tools are warmed and brushed over with the hot
solution as slightly as possible, and heated over a spirit lamp or slow fire until the required black
polish is obtained. Small tools done in this way should not be scrubbed, only wiped clean
and dry after using.

The Plasterers' Company. — The Worshipful Company of Plasterers was incorporated in
1 501. King Henry YIL, by his charter, dated loth ]\Iarch, incorporated the Worshipful Company
of Plasterers under the title of " The Master and Wardens of the Guild or Fraternitj- of the
Blessed Mary of Plasterers." Their grant of arms b>- Thomas Hawley, Clarencieux, is dated 1 5th
January 1546. A confirmation of their charter of incorporation, dated nth June 1667, grants
them the usual privileges of a guild ; a livery, a master, two wardens, and thirty-two assistants.

Their arms are '' Asiire on a c\\q\'xox\ gules, between a trowel and two hatchets, handles of the
second ; headed argent in chief, and a treble brush in base proper ; a rose gules seeded or, between

548 Plastering — Plain and Dccomtive.

two fleurs-de-lis of the first." "Let brotherl)- love continue" is their motto. Their book of
ordinances is an interesting volume. In i6S6 occurred one of tho.se " prentice " riots so famous in the
old time, and five of the prisoners proved to be of the Plasterers' Company. By an Act passed in
the sixth year of William and Mary, 1694, it was ordered that "whereas the Masters and Wardens
of the guild or fraternity of the Blessed Mary of Plasterers, London, are, and very anciently have
been, a brotherhood or guild, and for confirmation or strengthening of their jsrivileges have
obtained several royal grants, whereby their original constitution the said fraternity or guild ought
to be and consist of all persons using the trade of a plasterer in the city of London and liberties
thereof" — a fine being inflicted on those practising the art without being a member. A statute
was passed in the first year of the reign of James L, 1603, c. 20, which enacted that no plasterer
should exercise the art "of a painter in the city of London or suburbs of London," but an
apprentice was exempt from the meaning of the Act. The penalty was ^5, but a proviso allowed
the plasterers to use whiting, blacking, and red ochre mixed with size, without oil. This was a very
important statute, for it at once cleared up the several disagreements existing in 1575 between the
plasterers and the painters, the latter retaining their privileges by becoming incorporated in 1581.

The plasterers do not appear to have restricted themselves to the mystery of pargeters. In
1579 and 1585 two orders were made by the Court of Aldermen for settling matters in dispute
between the tilers and bricklayers and the plasterers, as to interfering in each other's trades. The
observance of these orders was enforced by an order of the Privy Council, dated ist June 1613, and
a general writ or precept issued to the same effect on 13th August 161 3.

The Plasterers' Hall is situated in Addle Street, Wood Street, Cheapside, London. Unfortu-
natel)' it is now used as an office and warehouse. Malcolm, who wrote in 1803, states that the rooms
were much ornamented with work peculiar to their profession, and the best artists belonging to it
were doubtlessly employed. Among the plasterers is found the name of Mr T. Brewer, author of
" The Life of John Carpenter," and "The Life of the late Alderman T. Kelly," citizen and jjlasterer
of London, and Lord Mayor 1836. J. Pirie, a member of the Plasterers' Company, was a Sheriff of
London in 1833. The members of the Company are not now of any particular trade. About twelve
plasterers are members of the Company. Only one apprentice has been bound under the auspices
of the Company during the la.st two decades. The Company has distributed for several years £2^
per annum in prizes to workmen in the trade, who become candidates for them at the Technical
Examinations at the City and Guilds of London Institute, and spend ^^15 per annum in ])hoto-
graphs and casts of the prize models, for distribution to Schools of Art.

Till-: Pl.\STEKKRS' Cr.VFT.— The plasterers' craft is one which shows the individuality of the
workman's touch, an essential feature, a desideratum justly regarded as a matter of high importance
at the present time. It is a craft entirely independent of machinery, demanding some exercise of
brain as well as skill of hand. There was once an American invention for executing plaster work by
replacing the hawk and trowel by a machine, but its labours ended at the Patent Office. In every
art or craft a perfect knowledge of the materials used, of their characteristics and applicability to
various purposes, is absolutely needful to ensure a satisfactory result for labour expended. The
plasterers' craft forms no exception to this rule. Many lamentable results have ensued from want
of attention in some instances, and ignorance in others, hence the need of care and knowledge of
the properties of the materials used. There have been man\- new plastering materials introduced
during the last few years, claiming fireproof, waterproof, strength, and sanitary properties, which
are herein described. London, with its 10,000 plasterers, is about the worst town in the United
Kuigdom for the employees. It is true they receive the maximum wage, but owing to the inter-

The Plasterers Craft. 549

mittent character of employment, high rents, and rail\va\' fares to far-off and ever-changing placed
jobs, their wages are practically reduced to the minimum. The time expended going to distant
work and returning to their homes, added to the actual working hours, makes a long and tiring
day, leaving but little time for rest, recreation, or self-instruction. Another evil which has cropped
up of late years is the system of sub-contracts, by which builders sublet their work to "piece-masters "
who contract for " labour onlj'." Builders who sublet their work supply plant and materials,
and as no other trade offers greater facilities for the adulteration of materials, there is often
adulteration to the extent of 30 per cent. Adulteration, scamped work, and cheap unskilled
labour, all combine to bring plaster work into bad re[3Ute, and cause serious injury to the trade.
Adulteration of materials should be made a penal offence, the same as adulteration of food.
Adulterated materials are often the cause of insanitary and unsafe buildings, and are also a loss
to the owners, and an injustice to the manufacturers of genuine materials.

There are man}' builders who have little, or more often no knowledge of plaster work, or of
the indixidual merits of their workmen, and simplj- trust to the foreman for the execution of the
work. In many instances the foreman is selected not for his superior knowledge of the trade, but
for his " gift of the gab," or his powers of driving and extracting the utmost amount of work out
of the men. If a foreman is conscientious, and has the courage to act fairly between master and
man, he is liable to be bullied, badgered, and dri\-en b}' the builder's general foreman. In London
the various branches of the building trade (a few special or fDatented branches being excepted) are
carried on by a master builder, and are under his control.

In most provincial towns there are fewer trades combined under one head, and the farther
north one goes the combination gets less and less, until each trade has a separate place and head
which finds all plant and materials. The division of trades creates a master or a master workman
for each trade, who, by concentrating his powers on his own special duties, is enabled to produce
sounder and better finished work than if he had to study and super\'ise six or seven trades. The
master plasterer having a fair business has a reputation at stake, and uses his practical knowledge
to protect it. In doing this he expends more time, and has greater intercourse with his men,
which generally leads to a better understanding between each other. He can also discriminate
between the skilled and the unskilled man. Provincial master plasterers have permanent shops
and a regular staff of men and apprentices, but in London, the richest, greatest, and most populated
town in the world, there are not a dozen legitimate master plasterers who have shops and apprentices.
This number does not include the firms engaged in the special production of fibrous plaster, carton-
pierre, papier mach^, and scagliola. Of these there are about half-a-dozen firms, and there is a
similar number of Italians who suppl\- jerry-builders with plaster cast work. A few of the London
builders do their own plaster work, and retain a regular staff of shop and building plasterers. The
London trade is principally recruited from the provinces. A London apprentice has during the last
generation become unknown. It is true that a few plasterers' sons learn the trade, but the\- do not
serve a regular apprenticeship, and move ^bout to where the largest wages arc obtainable, and are
often paid by their stature, and often before the}- attain their majority they develop into full-blown
plasterers. Benjamin Franklin says, " Good apprentices are most likel}- to make good citizens."
Good apprentices also make good workmen, and good workmen make good masters.

The mention of brickla\ers with plasterers in some of last centur}-'s records shows that there
was a combination of the two trades in some parts of the countr}-. Aspdin, the inventor of
Portland cement, was a bricklayer and plasterer. In some parts of the North of England even
at the present time plasterers are to be found who are also stone builders or " wallers," and in the

550 Plastering — Plain and Decorative.

North of Scotland the plasterer has generally some indoor trade for the winter months, such as
lath-rending, &c. The extracts as to whitewashing already quoted, and the prices mentioned
therein, prove that plasterers formerly had this branch of business in their own hands. How they
gave this up or lost it there is no evidence to show, but I have heard old plasterers say that
when trade was good they did not care about taking up whitewashing, and that consequently it
gradually fell into the hands of the painter. There are a few places where plasterers still do
whitewashing and lime-whiting. The red letter days of plasterers as regards wages were in 1876-77
at Glasgow, when wages reached as high as is. 3d. per hour, and in some instances is. 6d. All
sorts and conditions of plasterers flocked from London and other parts to that short-lived
El Dorado.

Ill London and the South of England plasterers formerly had attendants called "hawk-boys,"
each pair of plasterers having one to wait upon them. The hawk-boy's duty was to knock up
and gauge all the materials, keep the men's tools clean, look after the warming of their meals,
and serve the materials when gauged. The materials were gauged in a banker, which was
placed on the floor or scaffold, as the case might be. The boy gauged the materials with a
"server," and when he had finis-lied the gauge, shouted "serve," and lifted as much as would fill
the plasterer's "hawk." If the plasterer was on a mid-scaffold, a smart hawk-boy could throw
a serverful of stuff quite lO feet high. Their wages were from 2d. to 2id. per hour, and the
plasterer also gave them a few coppers on pay-day as tool money. When the Foreign Ofifices were
being erected, nearly a hundred boys turned out on strike for an advance of wages. Hawk-boys
are now a thing of the past, and it may be said that it is better for the trade that it is so, becau.se as
the boj's grew up, knowing the names and uses of the tools, a smart boy soon developed into a
so-called plasterer, and the market became swamped, to the detriment of the workman who had
fully and faithfully served his apprenticeship.

Sweating is not supposed to exist, but something nearly akin to it does, happily only to a
small extent at present. Some of the Italian figure casters now make plaster enrichments of the
sort used by jerry-builders. They also hawk about centre-flowers and trusses, which are chiefly
bought by small decorators and jerry-builders. Some of these plaster casters have a new method
of supplying the jerry-builder. They take old stock-moulds on to the job (where the builder fits
up a temporary bench in one of the rooms), and cast the enrichments there, thus saving the
expense of packing and carriage of the ornaments. It is needless to say that the jerry-builder
supplies the materials, and that the caster has only the price of his labour. Another form of
sweating has arisen since the introduction of the demon "piece-work" labour only, especially for
jerry-builders. A plasterer (commonly termed a " field-ranger ") gives a lump sum to plaster a
row of cottages, the draws for wages to be paid weekly. He then employs the cheapest labour
he can find, to help him in doing the work. They sometimes work so hard that they do "sweat."
Quality is ignored, quantity is their aim, and the only chance of gain. In some instances the
piece-worker has to work all hours, early and late, befor,e he can make a week's wage for himself,
and he sometimes succeeds in overdrawing so much, that to finish the job would only be thrashing
a dead horse. So he quietly lea\es, and seeks fresh fields and " plasters " new.

Few plasterers attain civic honours, but Mr Ralph Dodds was once Mayor of Newcastle.
" Raflie," as he was generally called, arrived in Newcastle with the proverbial " tuppence " in his
pocket, and worked his wa>- up from journeyman to master, and eventually to the Mayoralty.
He was of a humorous turn of mind, and many anecdotes are told of him. The following one as
connected with the trade will serve as an example. A certain lime merchant, being hard pressed for

Plastic Craft and Literature. 55 1

money wherewith to pay his men, called on Raffie for payment of an account which was scarcely
due. He stated his case, and was impatient as the hour for bank closing was near. Now it so
happened that years before, when Raffie first started business, this same lime merchant was a clerk
in a lime merchant's office where Raffie had credit. This clerk used to worry Raffie as to the
payment of his lime accounts. This was not forgotten when Raffie signed the cheque, which he
handed over to the merchant, who at once rushed off" to the bank, only to find that they would not
cash it, because after the signature came the two imposing letters M.P., and the bank clerk
stated he did not know any R. Dodds, M.P. The merchant being utterly dumbfounded, could
not explain, so he rushed back to Raffie, who fully expected him, and after quietly listening to his
sorrows, told him that he was an adjective fool, and that he ought to know that M.P. stood for
Master Plasterer as well as for Member of Parliament. Raffie, with his usual good-nature, then
told him the reason why he had added the two letters after his signature, and gave him the amount
in hard cash, with the advice never to be unduly hard on new beginners in business.

C. Fortune, a Harrogate plasterer, has also obtained civic honours, having been twice Mayor of
Harrogate ; he also holds the dual positions of Borough and County Justice.

According to the last census, there are no less than 34,905 plasterers in the United Kingdom,
of which there are about 10,000 in London, 1,000 in Glasgow, and about 300 in Dublin.

Novel and varied as may be the uses to which plaster work has been and may be applied, it
is regrettable that the craft is so unremunerative, that it almost ceases to enlist the skill and
intelligence of both master and operative men that the craft should command. This is mainlj- due
to the want of appreciation by the general contractor or builder, who is tempted by the question-
able economy of subletting the work to men of no mechanical standing. Another undeniable
factor is a want of early technical training in the nature and application of plastic materials. It
is hoped that the day is not distant when a general system of apprenticeship will be re-established,
and that it will be required of the artisan to provide himself with a proper and authorised certificate
of abilit}-.

No one can look round on the condition of the trade without being impressed with the fact
that a great change for the better is required. How this is to be accomplished no one can
accuratel}' say. It may be done partly by individual effort, partly by co-operation, and partlj- b\-
legislation. Competition between employers in London and other large towns, the constant effort
to undersell, cheap labour, bad materials, the adulteration of good material with inferior, the
insufficiency of materials (notably hair lime and good sand), and the general scamping of work,
have brought discredit on the trade. Good materials and work are spoilt by careless or
incompetent workmen, or by want of proper supervision. The bonds of good feMowship between
employers and employed should be broader and closer, to ensure mutual success and to avoid
failures, although failures are frequently the first steps towards success, and it may be truly said that
the man who never made mistakes never made anything.

With regard to plastic literature, it is a remarkable fact that although all other branches of the
building arts and crafts have been treated of in special works, that of the plasterer has not been
represented in technical literature. Some authors have slightly treated of the plasterer's craft in
connection with building construction, or in Encyclopaedias of Architecture, but most, if not all,
authors, when describing plaster work, make many palpable mistakes. It is probable that the
writer who first introduced the subject as a part of his work was so engrossed with his own
particular branch that he could not give plaster work due attention, or that, aware of his
want of plastic knowledge, he left the subject to some careless underling, who was either

55- Plastering — Plain and Decorative.

incompetent to give reliable information, or in his search for information was imposed upon, and
in turned imposed upon his employer. Other authors or would-be teachers of plaster work blindly
followed, like a flock of silly sheep following a leader. Only recently the Plasterers' Company
offered a series of prizes to plasterers' apprentices for the best description and examples of about a
dozen branches of the plasterers' craft, and as many of the branches named were new, the students
were referred to a well-known work on Building Construction. On referring to this work, a few
short notes are to be found, which are not only insufficient, but wholly incorrect and misleading. It
would take up too much space to enumerate even one-fifth of the errors, but the following are fair
samjjlcs. It is stated that "trowelled stucco is laid in pieces about 4 or 5 feet square, and the
workman, with a float in one hand and a brush in the other, floats the work until it is as smooth as
gliiss." Now it only requires a modicum of intelligence or thought to see that it is impossible to
get a partly soft or moist surface as smooth as glass with a wood float. Of course the work is
scoured with a hand-float, but it is the hard, smooth, and straight edge of the trowel that gives the
polish and renders the surface as smooth as glass. Again, laying the work in small pieces is
entirely wrong. In fact, it is never done by plasterers in the manner described. If laid in small
pieces, it would make a series of joints, which would be unsightly and difificult to make smooth and
true. F"loating is described as " consisting of fine stuff with the addition of a little hair, and derives
its name from being laid on with floats." Now a novice knows that floating consists of coarse
stuff, and that it is laid on with a laying trowel. It derives its name from the fact that it is a second
coat " floated " on the first coat, to form a solid straight surface for the setting coat. Another reason
for the name is that the surface is made straight (not smooth) with a floating rule. It is also stated
that " common stucco is laid on with a brush like whitewash, smoothed with a straight-edge, and
then rubbed with a hand-float, and brought to a hard and glossy surface." I have been in the
trade, and a seeker of plastic knowledge, for over forty years, and I have never seen or heard of
laying setting stuff with a brush (instead of a trowel or skimming-float), or of smoothing being done
with a straight-edge. This is used, as its name implies, to make the surface straight. As to the
glossy surface, it is done with a trowel, not by a float. It is by the contact and friction of two hard
surfaces (the consolidated setting stuff and the trowel) that the gloss or polish is obtained.

The term " fine stuff," which is used by some authors for " setting stuff," should be entirely
discarded. There are several degrees of fineness in most plastic stuffs, such as coarse, fine, and
superfine plaster ; coarse, fine, and superfine Keen's. Even in " coarse stuff" there is often a finer
quality used for floating ceilings (especially for panelled ceilings) than what is used for lathed walls,
and rendering, first-coating, &c. Therefore, the term, as applied to " setting stuff," is vague and often
misleading, especially as there are several degrees of fineness in this stuff, such as coarse, common,
and fine, which are used for different kinds of .setting arid stucco work. It seems ridiculous, or like
gilding gold, to name the finest degree of this stuff as fine, fine stuff. Fine stuff is described by
some authors in their passing remarks as "slaked lime saturated with water until of the consistency
of cream ... for some purposes a small quantity of hair is added." Now the veriest tyro will see
that this is simply lime putty. No mention of sand is made. Lime putty is described as similar to
fine stuff, but always used without hair. Even in lime putty there are two degrees of fineness— the
ordinary run lime, used for coarse stuff, and the fine putty used for running mouldings and making
setting stuff. Hence the necessity for the general use of the term "setting stuff," and the denomina-
tion of the other degrees of fineness, as fine or coarse, as required for the class of work.

Some authors also speak of " coarse gauged stuff," whereas it should be gauged coarse stuff.
The stuff may be of different degrees of fineness, but the gauging can only be medium or strong

Plastic Literature. 553

gauged, i.e., using more of the material which has setting powers. The gauge may also be stiff or
soft, but not coarse gauge. This then would rather imply that it was carelessly or improperly done.
Coarse stuff is a term solely applied to the material used for the first and second coats of lime
plastering, or when coreing or roughing out work with coarse plaster. Coarse or rough may be
correctly applied to denominate the degree of fineness of any material, such as coarse plaster, &c.

One instance will suffice to prove that the descriptions of tools are also ine.xcusably wrong.
A " darby " is described as being worked by two men. Just fancy, two men working a tool about
3 feet 6 inches long, and only weighing about 3 lbs. One author gravely asserts that a spade or
shovel is one of the principal tools used by plasterers. This is an infringement of the labourer's
rights.

The prices for plaster work in most books are vague and valueless. One writer gives a half-
hearted excuse and a lame reason for his want of practical information, stating that he " had not
been able to obtain sufficient data for carr}-ing them out (constants for the value of plaster work),
which, from the minor importance of this branch of building, is perhaps of no great importance."
Every class of building work is of importance, and every class of work that has to be paid for
should have a value. That such gross carelessness and incompetency could be shown by a professed
teacher is hard to believe, and that this teaching should be blindly followed b\- other theoretical writers,
and given in works of reference, is still harder to comprehend. The\- ma}- suit from a theoretical
point of view, but the>- will not stand a practical glance. Insufficiency of details or description
(if correct) may be pardoned, but for ignorant or careless errors there can be no excuse.

In 1829, a book entitled the "Bricklayers', Plasterers', and Slaters' Manual" was published, but
the information anent plastering is meagre and somewhat misleading. Recentl)- a work has been
published on plastering, which claims to be written b\- a plasterer, but b>- no stretch of imagination
can one think that it has been written by a practiser of the art of plastering. Amongst a host of
erroneous statements one maj- be mentioned, which will demonstrate to the veriest tyro the
improbability of this self-called plasterer e\er having been connected with the craft, viz., among
the tools illustrated is one which is, to all intents and purposes, a plumber's " shave-hook " (a
triangular piece of steel with a wooden handle), but it will scarcely be credited that this so-called
plasterer calls it a "jointing tool," and says that " it is employed for picking out and finishing off
angles and mitres to mouldings." In the same work it is stated that a darby is " about 12 feet long,
with a flat smooth face and a pair of handles, so that it can be operated or worked by two men."
This, combined with numerous and gross blunders in the methods of using the materials, proclaims
the author ignorant of the plasterers' craft.

APPENDIX.

Quantities of Plastic Materials required for various Works— Conxrete Quantities — Water
Quantities— Weights of Materials— Chemical Names— Measuring Plasterers' Work— Squaring
Dimensions — Recipes for Indurating, Fireproofing and Waterproofing, and Polishing
Plaster — Cleaning Plaster Figures — Whitewashing — Distempering — Glossary of Archi-
tectural and Plastic Terms, &c.

I.— plasterp:rs' memoranda, ouaxtities and weights.

Wf.ights and Cubic Contents and Quantities of
Materials Required per Superficial Yard.

Laths. — Length, from 2 ft. 6 in. to 4 ft.
Width, about i in.

Thickness — " Single laths," J to y j in.
Lath and a half, j\ to \ in.
Double laths, i to f in.
125 laths 4 ft. long = i bundle.

A bundle contains from 360 to 500 ft. run, most
frequently the former number.

30 bundles of laths = i load.

Laths are usually spaced from J to ^ in. apart,
according to their strength and nature of plaster.

A bundle containing 360 ft. run (or 400 nominally),
nailed with butt joints, will cover about 4} superficial
yards.

A bundle of 3-ft. laths requires about 660 nails, and
one of 4-ft. laths 630 nails, if nailed on to joists i ft.
from centre to centre.

Lathing nails are from 4 to i j in. long, according to
the thickness of the laths. They are either wrought,
cut, or cast iron, and they should be galvanised for
white cement work.

About 350 J-in. cut nails = i lb.

1,000 laths and 1 1 lbs. of nails will cover 70 super-
ficial yards.

A bundle of laths and 500 nails will cover about
5 superficial yards. Sawn laths are generally used in
America. They measure about \ in. thick, i^ in.
wide, and 4 ft. long.

Hair. — A bushel of dry hair weighs from 14 to 15
lbs. For best work, i lb. of hair is allowed to 2 cubic
ft of coarse stuff, and i lb. to 3 cubic ft. for common
work.

A barrel's bulk is 5 cubic ft.

Plaster. — 14 lbs. (London style) = i bag.
7 bags = I bushel,
i^ bush. = I cwt
2 cwt. = I sack.
10 sacks = I ton.

Parian Ce.ment.— Four bushels of cement, gauged
with an equal quantity of sand, will cover 10 super-
ficial yards h in. thick.

I sack of Parian = 2 cwt.

t cask of Parian = 2J cwt.

Keen's Cement. — A cask contains 4 bushels, and
when gauged with sand in the ratio of i part of cement
to 2 parts of sand, will cover about 15 superficial yards
i in. thick. One sack of Keen's = 2 cwt.

Martin's Cement. — One cwt., gauged with equal
proportions of sand, will cover about 7 superficial yards
A in. thick.

Robinson's Cement. — One cwt. of cement and i
of sand will cover 7 superficial yards J in. thick. One
cwt. of cement and 2 of sand will cover 1 1 super-
ficial yards i inch thick. One cwt. of cement and 3
of sand will cover 15 superficial yards i in. thick. One
cwt. of neat cement (No. i) will cover 15 superficial
yards ~ in. thick. These proportions are by measure,
not weight. One cwt. cement equals about ih im-
perial bushels.

Adamant. — Adamant (No. 2) for floating walls,
weighs 155 lbs. per sack, and will cover 7 superficial
yards. Adamant (No. 2) for floating laths, weighs
130 lbs. per sack, and will cover 7 superficial yards.
Adamant (No. 3) for setting coat, weighs 140 lbs. per
sack, and will set 30 superficial yards.

SiRAPiTE. — One ton mixed with an equal portion

556

Appendix.

of sand will cover about 120 superficial yards | in.
thick ; I ton of jnire sirapite will cover about 300
superficial yards.

Granite Plaster. — \\ tons of render on "sawn
laths" will cover about 100 superficial yards \ in.
thick, and 1 ton of X of finish will cover about 300
superficial yards.

Resiall'.s Adamantine Plaster. — For wall work
an admixture of i part sand to 2 parts adamantine
is allowed for a floating coat, which is skimmed with
pure adamantine only. No admi.xture of sand is
allowed for ceiling or lath work.

One bag of pure adamantine (iSo lbs.) will cover
about 6 superficial yards.

Wall work in Birmingham is done (including labour
and all material) at about lod. per yard.

Ceiling work in Birmingham (including labour,
lathing, and material) is done at about is. 5d. per
superficial yard.

Mastic. — One cwt. of mastic and i gallon of oil
will cover 5 superficial yards \ in. thick.

Fii'.ROL's Plaster Slabs. — Slabs i in. thick weigh
when dry 2J lbs. per superficial ft. Fourteen lbs. of
nails will fix 100 superficial yards.

CIelatine. — Two lbs. of gelatine when dissolved
will cover about i superficial foot \ in. thick.

Wax. — 5 lbs. of moulding wax will cover i super-
ficial foot about I in. thick.

Silicate of Coiton. — One cwt. will cover 100
superficial feet about i in. thick.

LiMEWHiTE. — Limewhite once done requires i cubic
foot of slaked lime per 100 superficial yards ; twice
done, I \ cubic feet of lime.

M'hitewash. — 100 yards superficial "once" done
requires about i2 lbs. of whiting. \ lb. of blue-black,
and \\ gallons of size.

100 yards superficial " twice " done requires 21 lbs.
of whiting, } lb. of blue-black, and 2 J gallons of size.

1 firkin of double size = 48 lbs.

2 dozen whiting = i cwt.

Lime. — 100 tons of blue lias lime yield 59.37 tons
of quicklime ; 1,583 bushels of ground lime, 2,063
bushels of slaked lime.

74 gallons of water are required for slaking i ton
of quicklime.
I ton of quicklime = 30 bushels.

1 I' .. =27 bush, ground lime.
3 bush, ground lime = i .sack.

9 sacks „ = 1 ton.

2 yards of lime = i ton.

Render only ^ inch } S
thick - - - ^ Hair
(. Water
I Lime

Render and set i in. ) Sand

Lime (unslaked).

Sand

21 bushels (striked), or 27 cub. ft. of lime or sand
= I cub. yard.

3 bush, of lias lime = i sack.

9 sacks „ = I ton.

36 bushels ,, = I loud.

One cubic yard of lime, 2 yards of sand, and 3
bushels of hair, will cover 75 superficial yards, if ren-
dered and set on brick, and 70 yards on lath, or 65
yards render float and set on brick, and 60 yards on
lath. One cubic yard of coarse stuff equals i cart
load.

Lime Plastering Quantities. — Quantities of
lime, sand, hair, and water required per superficial
yard for various classes of plastering : — •

•15 cub. ft.

■23

■I lb.
I • 2 gals.
■22 cub. ft.

■23 •.

•12 lbs.

1 '8 gals.

•25 cub. ft.

•3« ->
•17 lbs.

2 "o gals.

•32 cub. ft.

•38 „

•18 lbs.

2 '6 gals.

•10 cub. ft.

•03 "

I 'GO gals.

For rough walls, the quantities should be slightly
increased. The first coat on lath requires about one-
tenth more coarse stufT than rendering.

The following is the method of calculating the above
proportions to ascertain the amount of materials re-
quired for any given quantity of work to be executed.
Multiply the quantities given in the above tables by
the number of superficial yards of work required to
be done. Example — What quantities of lime (un-
slaked), sand, hair, and water w-ill be required to
render 50 superficial yards and | in. thick ?

Process. — Lime - . ts

thick

) Hair
( Water
( Lime
) Sand

Render

and

float

in. th

<-k

1 Hair
' Water

( Lime
3 Sand

Render,

float,

and

set

\m.

thick

\ Hair
(. Water

Setting with putty
and plaster i in.
thick -

Lime (unslaked).
Plaster -
Water

Sand

7 '5° = 7^ cubic feet.
"23
50

11.50

iij

Memoranda.

557

Hair

Water

•I

5°

5-0 = 5 lbs.

I'2

6o'o = 60 gallons.

And in a similar manner for other descriptions and
quantities of work.

Selenitic. — Three bushels of selenitic = i sack.
36 bushels = I ton.

Reduction in Bulk of Materl^ls. — The reduc-
tion in bulk of dry cement when mi.xed with water is
10 per cent, of the total ; of sand, 20 per cent.; and
of sand and cement in equal proportions, 19 per cent.

Porosity. — The relative porosity of limes and
cements is as follows: — Common lime mortar (i to
2), too; plaster of Paris, 75; Roman cement, 25;
and Portland cement, to.

Table XVII. — Quantity of Mortar Produced
FROM One Imperial Bushel of Various Limes
AND Cement.

Lime or cement.

•3

6S.

&•"'=

Description.

5 2 3

6-?

T3 3

i"
i

r Stone lime (Plymouth)

,SA*

Lias (Keynsham)

3tV*

,, (Lyme Regis) -

2it

I „

3it

-6

Lias (Keynsham) -

6.1

,, (Lyme Regis) -

Roman cement

• Six gallons of water are required to slake, and 6 gallons to mix each
bushel.

t Two gallons are required to slake each bushel.

Roman Cement. — One cask of Roman cement
holds 3j cubic ft., and the weight is about 3^ cwt.
Three bushels of cement = i sack. One bushel of
cement and i of sand will cover 4^ superficial yards
\ in. thick.

Portland Cement. — Two centals (200 lbs.),
London trade custom =1 sack. Two bushels, Mid-
land trade custom = i sack. One cask of Portland
holds about 4 cubic ft. One cask varies from 375
to 400 lbs. gross, general London custom, for e.xport.

Table XVIIL— Superficial Yards, rendered with
Portland Cement gauged with Various Pro-
portions of Sand, and in Various Thicknesse.s.

Proportions.

Thickness.

\ in.

|in.

iin.

\\n.

I in.

I bush, of rement, neat -
I „ ,, and I of

2| yds.

2|ycls.

2 yds.

I J yds.

1 yd.

sand
1 bush, of cement and 2

45 >>

31 „

35 .,

2i„

2i..

of sand -
I bush, of cement and 3

6f „

Si..

4i „

4 ..

3J„

of sand -

8i„

7*..

6i „

5f ..

41..

Note. — j in. is the usual thickness.
Table XIX.— Quantity of Materials (in Various

G.^UGES) REQUIRED TO MAKE ONE CUBIC YaRD

of Gauged Portland Cement and Sand.

I and I

and

I and

Cement -

- 12-62 bushels.

Sand

- 12-62

Water -

30 gallons.

Cement -

837 bushels.

Sand

- 16-74 „

Water -

25 gallons.

Cement -

6-37 bushels.

Sand

- 19"" ..

Water -

23 gallons.

One cubic yard of gauged Portland cement and
sand will render 70 superficial yards.

Comparative Strength of Portland Cement
and Sand, in Various Proportions. — At the end
of one year after setting, i of Portland cement and i
of sand is about three-fourths the strength of neat
cement ; i of cement and 2 of sand is about one-half
the strength of neat cement ; i of cement and 3 of
sand is about one-third the strength of neat cement ;
I of cement and 4 of sand is about one-fourth the
strength of neat cement ; i of cement and 5 of sand
is about one-sixth the strength of neat cement.

Weight of Various Cement Concretes h.-vving
Various Aggreg.^tes in Lbs. per Cubic Foot. —
The concrete consists of i part of cement to 3 of
aggregate. As the weight of different kinds of the
same class of aggregates varies, the average weights
of the concrete are given : —

Table XX.— Weights of Various Concretes.

lbs.

Pumice-stone concrete

Coke-breeze concrete ■

Brick concrete - - - -

120

Limestone concrete -

130

Slag concrete . - - -

140

Gravel concrete - - - -

'45

Granite concrete

"45

558

Appeudix.

Tai!

i.K X.\l.— Weic.hts of Various Plastic
Materials per Cubic Foot in lbs.

lbs.

Ashes -

Mortar, old -

Clay, common

125

„ new

„ modelling -

120

„ well tem-

Cement, Portland -

pered -

„ Roman -

Plaster of Paris,

Chalk -

125

cast -

Gravel ■

113

Red pine wood

(Apsuin. natural -

140

Sand, dry

100

Hair, ox, dry

„ wet

"3°

Lime, ^frey chalk, \

Shingle

in lump /

Thames ballast -

Limestone -

Wax -

The weight of a superficial yard lath plaster, float
and set ceilings of good quality, is about 98 lbs. II
of inferior quality, it would be about 8 lbs. less.

Rough-CastingQuantities. — For 100 yards super
ficial of rough-casting (two coat on lath) the follow-
ing quantities are required : — 25 cubic feet of lime,
50 cubic feet of sand, 16 lbs. of hair, and f yard of
prepared gravel for the dash coat. \ quarter tub of
lime putty should be mixed with every tub of gravel
for the dash. To colour 100 yards superficial in any
of the tints named herewith, the following quantities
of ingredients are required : For a blue-black, 5 lbs. of
lampblack; for buff, 5 lbs. of green copperas, to which
add I lb. of fresh cow-manure, strained and mixed
with the liquid dash. A fine terra-cotta colour is
made by using 14 lbs. of red metallic oxide, mixed
with 5 lbs. of green copperas and 4 lbs. of lampblack.
The addition of 10 per cent, of alum solution to the
liquid dash will give brilliancy and permanency to
the colours. \'arious tints of these colours may be
obtained by varying the quantities given.

Concrete Quantities.— One sack of Portland
cement (10 sacks to i ton), gauged in the ratio of 2 of
cement to 5 of aggregate, will fill in 12 ft. run of
moulded spandrel steps, i2in. tread and 7-in. rise, or
about 5 cubic feet.

Concrete paving slabs 2 in. thick weigh about
26 superficial lbs., or 9 superficial yards to i ton.

Concrete Foundations. — It takes about 1 cubic
yard of brickbats, stone, &c., to form 10 superficial
yards of dry foundations 3 in. thick.

Eureka Concrete Quantities. — One sack of
Portland cement (10 to the ton) gauged with 2i sacks
of aggregate will cover 4J superficial yards 2 in. thick.
One ton of Portland cement, gauged with zh parts
(in bulk) of aggregate, will cover about 40 superficial
yards 2 in. thick. The quantities vary according to
the closeness and compactness of the dry foundation.

The quantities are slightly less for concrete founda-
tions.

Granite Concrete Paving Quantities (Various
Thicknesses). — One sack of Portland cement (10 to
the ton) and 2 sacks of crushed granite will cover the
following surfaces : —

Tari.e .\.\II.

I2i super, yds. i in. thick.
6? „ „ I in. „
4* „ „ li in. „

3^ super, yds. 2 in. thick.

2 „ „ 2.V in.

A " '. 3' in. „

A sack of granite weighs nearly the same as a sack
of Portland cement, so that when calculating by
weight, the bulk of each can be reckoned about
equal.

Weight ok Various Aggregates. — The following
materials weigh i ton, as filled into carts :^

21 cubic ft. of river sand.

22
22

23
24

]jit sand.
Thames ballast,
coarse gravel,
clean shingle.

Water and Heat Mejioranda. — A medium-
sized pail will hold 3 gallons of water. A pint of
water weighs about i lb., and is equal to about 27
cubic ill., or a square box 3 in. long, 3 in. wide, and
3 in. deep.

I gallon of water equals 272'i23 cub. ins.

I ,, ,, (United States) 23i'o „

6J ,, ., I cubic ft.

I cubic ft. of water weighs 4 lbs.

Salt water is heavier than fresh, and weighs 64'ii
lbs. per cubic ft.

Water freezes at 32°, and boils at 212° Fahr.

The following table shows the relative heat con-
ducting power of various materials : —

Table X.XIII.

Silicate cotton or slag wool - -100

Plaster of Paris - - - -125

Sawdust - - - - - 163

Coke-breeze . . . . 230

Bushel Bo.x. — A box 13 in. x 13 in. and 13I in.
deep will hold i bushel of Portland cement. Another
size, 12 in. x 12 in. and 15!,- in. deep. All inside
measurements.

I bushel contains 22iS-i92 cubic in.

I „ ,, (United States) 21 50^42 .„

Ti.MBER. — Timber is now largely used by plasterers
in the construction of fibrous plaster, and for concrete
moulds and centring. A brief description of the
terms and sizes may prove useful.

Memoranda.

559

Timber is cut into various sizes, and the timber
merchants use the terms "planks," "deals,"
"battens," "boards," "scantling," and "quartering."
Planks are pieces of wood ii in. wide, 2\ in. or 3 in.
thick, and may be bought in lengths from 8 to 21 ft.
Deals are 9 in. wide, 2i in. or 3 in. thick, and of the
same lengths as planks. Battens are 7 in. wide, 2\
in. thick, and likewise of the same lengths as planks.
Boards are of less thickness than planks, deals, or
battens, and are distinguished by their thickness, as
"half-inch-board," " three -quarter- board," "inch-
board," and so on ; but they are often spoken of as so
many "cuts," as "three-cut," "four-cut," "five-cut,"
&c., which means that the plank or deal, 3 in. thick,
is divided by the number of saw cuts mentioned ;
thus, five cuts would divide the plank or deal into six
boards, each being i in. thick, less the portion cut
away as sawdust. Scantling simply means a quantity
cut to any desired size for any purpose.

In a London deal standard there are 120 deals.
12 ft. X 9 in. X 3 in. = 1080 super, ft. = 270
cubic ft.

120 deals = 100.

100 super, ft. of planking = I square.
50 cubic ft. of squared timber 1

600 super, ft. of I in. planks or deals ■ i load.

400 ,, \\ ., ., )

One square of centring requires 12 boards 12 ft.
long and 9 in. wide.

An allowance of one-third to one-half is usually
made for centring, &c., on reconverting to use.

Wood for special templates, squares, thin or circular
strips, or laths for fibrous plaster work, is not so liable
to crack or warp if steamed or boiled in hot water for

three or four hours, and then slowly dried.

Table XXIV.— Analysis and Cost of Materials and Labour for Plaster Work.

Chemical Names of Co.mmon Substances used
BY Plasterers.

Common Name.

Chemical Name.

Lime

- Oxide of calcium.

Slaked lime

■ Hvdrate calcium.

Muriate of lime

- Chloride of calcium.

Plaster of Paris

f Sulphate of lime ; also
1 selenite.

Chalk -

- Carbonate of calcium.

Copperas or green vitriol

- Sulphate of iron.

Blue vitriol

- Sulphate of copper

White vitriol -

- Sulphate of zinc.

Oil of vitriol

• Sulphuric acid.

Potash -

Oxide of potassium.

Red lead

- Oxide of lead.

Sugar of lead -

- Acetate of lead.

Iron rust

- Oxide of iron.

Alum, dry

( Sulphate of aluminium
i and potassium.

Common salt -

- Chloride of sodium.

Soda

- Oxide of sodium.

Sand

- Silica.

Plaster and Concrete Colours on r)R.\wiNGS. —
Plaster work on architectural drawings is indicated by
a grey colour ; cement work by sepia or Payne's grey ;
and concrete by a blue colour.

Value of Plaster Work. — In 1874, Major
Seddon, R.E., made a series of experiments with a
view to ascertain the amount of labour and material
required for a given number of yards of plaster and
cement work. The results are given in the subjoined
table. The cost of scaffolding and carriage of mate-
rials are not included in the prices. The prices for
labour and materials may be altered to suit local and
present rates. These trials are valuable, inasmuch as
it is certain that no vested interests were concerned,
and that the experiments were made under proper
conditions.

Materials and Labour required
for 10 sup. yards.

Render One Coat
and Set.

Rene
an

er Float
d Set.

Lath Plaster
and Set.

Lath Plaster, Float,
and Set.

Portland Cement.

Render Float and Trowel,

I cement and 2 of sand.

Description.

Value.

Quantity

S. d.

Quantity

s. d.

Quantity

s. d.

Quantity

s. d.

Quantity

£ s. d.

Chalk lime, cub. ft.

s. d.
4

I 8

2 I

I 10

- 3

Sand „

Sand, washed „

I 6

Hair, dry, per lb.

Water, per gallon

-5

Lath (lath and I

half) per bundle /

4 6

...

Lath nails, per lb.

...

Portland cement, 1
per bushel J

2 6

...

063

P asterer, per day

S 6

I 10

2 9

4 li

6 loi

Labourer, „

2 9

I 4*

• 4*

2 o|

035}

Apprentice, „
Cost, per 10 yards

I 6

9
8 6|

9
13 2

— -

I \\

~i6"^r

18 l|

6 3

Cost, per yard

io|

I 3J

...

■ 7A

I 9I

$6o

Appendix.

Measuring Plasterers' Work. — Plasterers'
work when entered into the dimension book is
generally treated with the following abbreviations.
"F.P." .stands for fibrous plaster: "R." for render;
"R.S." for render and set; "R.F.S." for render,
float, and set; "L.P." for lath and plaster;
"L.P.S." for lath, plaster, and set; "L.P.F.S."
for lath, plaster, float, and set; "W.S.C.W.' for
wash, stop (elaircolle), and whiten ; " L.W." for
Hme white; "L.O." for labour only; '-L.M." for
labour and materials; "P.C." for prime cost;
"dd." for deduct; "cub." for cubic; "super." for
superficial; "yds." for yards; "ft." for feet; "in."
for inches ; a tick or dot also placed after a figure
or figures is intended to describe feet, while two
dots means inches, thus 3' 9" stands for 3 ft. 9 in.

Various forms of plaster work are measured by
the yard and foot superficial, per foot lineal, and per
inch girth. Per yard superficial includes render and
set, trowelled stucco on brick lath, lath and plaster
on walls and ceiling.s, fibrous slabs, and plain face,
render float and set in cements for floors, walls, and
ceilings, lime whitening, or colouring, washing, stop-
ing, and distempering.

Per Foot Superficial. — Cornices (over 6 in. girth),
plaster and cement sofiSts, bands, margins, fascias,
])anels, dados, pilasters, columns, and large plain
coves.

Per Foot Lineal. — Plaster or cement reveals, skirt-
ings, narrow bands, and margins, arrises, beads, quirks,
reveals and string courses, and enrichments.

Per Inch Girth. — Mouldings 9 in. girth and under,
and enrichments with circular profiles. Centre flowers,
capitals, trusses, &c., are numbered ; the cost of
modelling is generally allowed for in the prices, but
as the modelling is a distinct and important part of
the work, the cost of same should be charged as a
.sei)arate item, the design and nature of the labour,
and the quality, being carefully described, and any
s])eciality always mentioned.

Enrichments are numbered and charged separately
according to schedule. Measure ceilings from wall to
wall, and take out one projection of cornice. Measure
walls from the top of skirting or wood grounds to
half-way up the height of cornice for lath work, and
one-third for brick work. Plaster work, if circular on
plan, is measured one and a half times the girth by
the height, and the area added to the plain work. If
circular work is described and allowed for in the
specifications, the girth is taken single. Panelled
work is taken by the round of the panel, as square
arris or moulding, and describing the girth of the
mouldint;.

All enrichments to be taken distinct from the
cornice, which is to be taken as plain, cornice being
girthed in full.

All mitres over four in number to be charged each
at the price of a foot run of moulding. Stops charged
the same as mitres. Return mitres are charged as two.

Dubbing out with tiles or gauged stuff, in order to
get an extra thickness or projection, or if the work is
out of upright, is measured by the foot superficial,
unless for narrow string course, when it is taken by the
foot run. Internal and external work is always kept
separate, and the various kinds of work, materials,
and number of coats are always fully described.

Deduct all openings, with the exception of small
oblong or circular window.s, or ventilators, and columns,
where the labour working round them is more than if
the space had been done. Additions or joints with
old work are measured i foot over the joints, to
allow for the labour cutting and making good the
joint. Patches are not measured, but charged time
and materials.

For small triangular parts and closets, where shelves
are in, it is customary to add one half of the measure-
ment to the measurement, to allow for extra labour
of plastering such work.

Cement floors are measured by the superficial yard,
describing the proportions of sand (or other aggregate)
and cement, but small works, such as hearths, cisterns,
&c., are taken by the superficial foot.

Squaring Dimensions. — Lineal measure relates
to length only. Superficial measure to length and
breadth. Cube, or solid measure, to length, breadth,
and thickness. If feet are multiplied by feet, the
product will be feet. If inches are multiplied into
feet, every 12 of the product will be feet. If inches
are multiplied into inches, every 12 of the product
may be reckoned as an inch, and any number less
than 12 as parts of an inch. If parts of an inch are
multiplied by feet, every 12 of the product will be i
inch, and any number less than 12 will be parts of an
inch. If parts of an inch are multiplied by inches,
every 12 of the product is i part, and any number
less than 1 2 are seconds.

There are various methods of squaring dimensions.
The following are generally used. The primary object
in all cases is to find the contained number of square
or superficial feet and parts of feet, and having found
the number, divide by 9, which gives the number of
superficial yards. The dimensions of length and
breadth expressed in feet and inches are multiplied
together by duodecimals, and the result is the number
of "superficial " feet and parts of a foot.

The first method is usually known as cross-multipli-

Memoranda.

561

cation, and will be explained by the following example.
Find the contents superficial of a wall 11 ft. 4 in.
long and 7 ft. 5 in. high. The process is as follows :
Set down the figures with a cross between them,
thus —

Ft. In.

Fl. In.

I I X 7

5 X II

4 X 7

/ /
4

4 =

8 pts.

Total contents

. 84 o 8 pts.

The following simple method of calculating for
multiplying ft., in., and parts, and which holds good
either in cubic or square measurements, is to remember
ft. X ft. give ft. ; ft. x in. give in. ; in. x in. give
in. ; in. x pts. give pts. ; pts. x pts. give thirds., &c.

Example. — 11 ft. 4 in. x 7 ft. 5 in. are multiplied
thus —

Ft.

In.

Pis.

84 o 8 Ans.

Another method may be shown by example : — Find
the contents (superficial) of a wall 14 ft. 7 in. long
and 9 ft. 2i in. high.

Process. — Set the figures down thus —

Ft. In. Ft. In.
14 7x9 2\
Ft. In. Pts.

14 7

926

7 3

2 5

131 3

140 II 8 Ans.

A quick way. Find the superficial contents of a
ceiling 20 ft. long and 18 ft. wide.

Process. — 180 x 2 = 360 superficial ft.

Find the contents (superficial ft.) of a margin 21 ft.
long and 18 ft. wide.

Process. — As 18 in. equals li ft. ; thus 21 x i| = 3iJ
superficial ft. : or 31 ft. 6 in. superficial.

To find the superficial contents of a cylinder or
column. Multiply ihe diameter by the length, and
the product by 355, and divide the last product by

113; the quotient is the superficial contents. Another
way is to multiply the circumference by the length ;
the product is the superficial contents.

Another way still is that the superficial contents are
found by multiplying half the diameter by itself, and
the product by 3! ; or in other words, multiply the
square of the radius by 22, dividing by 7 ; the product
is the superficial contents of the whole circle. If it is
only half a circle, multiply by 11 instead of 22.

To Me.\sureTri.\ngles. — Triangular piecesof work
are measured by taking the length of one of the sides
by half of its perpendicular distance from the opposite
vertex (point of angle) ; these dimensions, when mul-
tiplied together or squared, will give the superficies of
the triangle. Other irregular figures are measured in
the same way, by dividing them into triangles.

To Me.^SURE IRREGUL.A.R WIDTHS. — If a wall or
other surface is wider at one end than the other, add the
width of both ends together ; half the sum is the mean
width, then multiply the mean width by the length.

Cube or solid measure is not much required in
ordinary plasterers' work, but as artificial stone work
is coming largely into use, and being done by plas-
terers, the following examples are given.

The dimensions of length, breadth, and depth,
e.xpressed in feet and inches, are all multiplied to-
gether by the usual method as employed in superficial,
and the result is obtained in cubic feet, I2ths, and
i44ths. Thus to find the contents of a pilaster, 11
ft. 3 in. long, I ft. 2 in. broad, and \\\ ft. deep.

Process. — First multiply 11 ft. 3 in. by i ft. 2 in.,
which gives superficial feet, i2ths, &c., and multiply
that result by iii in., which gives cubic ft., i2ths,
&c.

Thus-

Ft. In. Ft. In. In.
II 3x1 2 X I li

Ft. In.

■I 3

I 10
II 3

13 I

ultiplied by 1 1

6 superficial ft.
6

6 6
12 4

9
6

12 611 3 cubic or solid ft.
The 1 2th of a cube foot must not be confounded
with the cubic inch, as it really contains 144 cubic
inches.

A quick way for the same operation is to find the

562

Appendix.

contents (cubic) of 6 caps, each i ft. by i ft. 2 in.

by I J ft.

Multiply together the length, breadth, and depth of

one cap in feet, and tiie large.st fractions of a foot, and

multiply by the given number of caps, thus—

1x7x7x6 . .

; — = = 1 2+ cubic ft.

6x4 *

An old way to find the contents (cubic) of a window
head 6 ft. long, 10 in. wide, and 7 in. deep.

Multiply the length by breadth, and the product by
the depth. Multiply this product by 12, and divide

by 1728. The result is 2 cubic feet and -^.
' 1728

Thus —

6 ft.
10 in.

7 in.

420
12 in.

840

420

The inches in

a solid foot 1 728)5040(2 ft.

3456
The inches in

a quarter foot 432)1584(3 quarters 288 in.

288

A short way is performed thus —

Fr. In. In.

6 x 10 X 7

Ft. In.
6 O

5 o

A method of calculation for showing the contents
of a cubic foot in cubic inches is : — Find the con-
tents of a concrete block 1 2 in. by 1 2 in. by 1 2 in.
Multiply the length by the breadth, which gives the
superficial contents. This multiplied by the depth
gives the cubic contents. Thus —

The diameter of a circle being given, find the
circumference. As 7 is to 22, or as 113 to 355, so is
the diameter to the circumference.

Example. — Find the circumference of a circular
panel moulding, the diameter of which is 1 2 feet.

Process. — Multiply the diameter by 355, and divide
the product by 1 1 3. Thus —

355

13)4260(37 ft. -rW of a foot.
339

870
79'

The circumference being given, the diameter is
found by dividing the circumference by 3!.

Example. — Find the diameter of circular panel
moulding, the circumference of which is 1 1 feet.
Thus —

11x7

= 3Ut.

12 in.
12

contents,
in. or I CL

bic ft.

144 super.
12

1728 cubic

Another way is — Multiply the circumference by
113, and divide the product by 355.

To find the area of an ellipse, multiply the long
diameter by the short diameter, and by the decimal
.7854, and the product will give the area.

To find the cubic contents of a true tapered
pyramid, whether round, square, or triangular. Mul-
tipl)- the area of the base by \ the height.

To find the cubic contents of a cylinder. Multiply
the square of the radius by the thickness, both in feet
and fractions of a foot, and the product by 3i.

Another way is to multiply the square of the
diameter by the thickness, both in inches, and divide
by 2200, and the product is in cubic feet.

Another way : Multiply the square of the diameter
by 7854, and the product by the length.

A cylindrical foot is the solid contents of a cylinder,
I foot in depth and diameter, and is equal to 1728
cylindrical inches. Cylindrical inches + 7854. =
cubic inches.

To find the superficial contents of a circle. Multiply
the half diameter by itself, and the product by 3 1, or
in other words, multiply the square of the radius by
22, and divide the product by 7. This gives the
superficial of the whole circle. If it is only a half
circle, multiply by 11 instead of 22.

Example. — Find the contents of a circle, the
diameter of which is 1 2 feet.

Recipes.

S63

Process. — First square the half diameter, or radius.
Thus—

6
6

36
22

72
72

7)79z(ii3t-

Another way is to supply the square of the
diameter by the decimal .7854; or multiply the cir-
cumference by the radius, and divide the product
by 2.

And yet another way : The diameter being given,
multiply the square of the radius by 3*.

Example. — Find the area of a circle panel, the
diameter of which is 36 inches. Thus —

3x3x22 _

= 7-07 ft.

II.— RECIPES FOR PLASTER WORK.

To Harden Pl.^ster Casts. — Numerous patents
have been obtained and many methods used for
hardening plaster casts. The following are some of
the most simple and effective methods. In order to
obtain the maximum of hardness, the plaster should
be gauged as firm and as quick as is possible. When
plaster is hardened by soaking or coating with a
solution, the work should be perfectly dry, and also
warm, so that the solution may penetrate more easily.
Where practical, the casts should be immersed in the
solution. The work of hardening and polishing should
be done in a clean, dry, and warm room, free from
draughts of cold, or damp air, or dust.

The addition of about 5 per cent, of good corn-flour
to plaster renders it hard and tough. This admi.xture
is useful for casting plaques and similar ornaments.
Ground rice is used for a similar purpose.

Plaster casts can be made extremely hard and tough
b)- adding pulverised marsh-mallow root to the plaster,
also by gauging the plaster with the water in which
marsh-mallows have been boiled. If the plaster is
gauged with 4 per cent, of finely pulverised marsh-
mallow, the setting is retarded for about one hour.
\\'hen dry, it may be filed, sawn, or turned. With
8 per cent, of marsh-mallow the setting is further
retarded, but the toughness and hardness is increased.
This may be rolled out on glass in thin plates. It
may be used as a substitute for carton-pierre, also for
the manufacture of enrichment or mouldings that
have to stand rough usage, also for frames, brackets,
panels, &c. This material will take a good polish.
Plaster casts may be rendered hard by soaking in or
brushing with a hot solution of strong alum. Plaster
casts formed with marsh-mallow, as above, and soaked
in a hot solution of alum, renders the casts as hard
as stone and as tough as wood, and capable of
receiving a polish equal to marble. A sharp blow

will cause an indentation rather than shatter it. It
forms a good surface for paint or gilt. Plaster ca.sts
are rendered hard by soaking in or brushing with a
hot solution of stearic acid and soda lye. Plaster
casts are hardened by soaking in a hot solution of
stearine. The casts by this method may be polished
by rubbing with soft rags or cotton wool, also with a
soft brush. Plaster casts may be rendered hard and
impervious to damp by soaking them in a hot solu-
tion of parafifin wax. The}' may also be rendered
hard and tough by soaking in linseed oil for ten
hours, then air drying and soaking again for six hours.
Warm glue size is also used for a similar purpose,
and also by soaking the casts in strong solution of
potash alum. Soaking in sulphate of zinc is also
useful for this purpose. The immersion should not
exceed two hours ; if immersed longer the plaster will
become friable. Plaster immersed in a strong solu-
tion of borax, gradually heating it, becomes nearly as
hard as marble, and may be polished in like manner.
Plaster casts immersed in . paraffin oil become hard,
and assume a fine surface.

Plaster and Portland cement (cast or laid) work
may be rendered hard and tough by gauging the
material with from 10 to 15 per cent, of minion.
Minion is the siftings of ironstone after calcination.
Signor Abati, of Naples, found that by combining
plaster with the minimum quantity of water, by the
application of steam, filled into moulds and submitted
to hydraulic pressure, the cast became as hard as
marble and as susceptible to polish.

New Mode oi' Hardening Plaster. — Mr Julhe,
in a note presented to the Academic des Sciences,
describes some experiments that he has performed
with a view to rendering the use of plaster still more
general. Of all materials used in building, plaster is

564

Appendix.

the only one which increases in bulk after its appli-
cation, while mortars and cements, and e\en wood,
undergo shrinkage and cracking through dr)ing.
When ap])lied in sufficiently thick coats to resist
breakage, it offers, then, a surface that time and
atmospheric variations will not change, provided it
be protected against water. But it is necessary to
give this material two jjroperties that it lacks -hard-
ness and resistance to crushing. This is what Mr
Julhe proposes to effect by his process. Si.x parts of
plaster are mixed with one of finely sifted unslaked
lime. This mixture is used like ordinary plaster for
moulding any object whatever, and, when once dry,
the object is soaked in a solution of a sulphate having
a base precipitable by lime, and the precipitate of
which is insoluble. These form sulphate and oxide
of lime, both of them insoluble, which fill the pores
of the object and render it hard and tough. Sulphates
of zinc and iron are the salts that answer the purpose
best. With the first the object remains white, and
with the second it gradually assumes the tint of
sesqui-oxide of iron.

Polishing Plaster Casts. — Plaster casts can be
made to take a high polish. Those which are to be
polished by friction with other substances should be
made as hard as possible. The plaster should be
gauged firm, and used expeditiously. When a soft-
gauged plaster is necessary to allow it to be run into
closed up moulds, the cast may be partly hardened
by dusting the back with dry plaster to absorb the
moisture, (lauging with alum water hardens plaster,
but causes it to set too quick for manipulation in
certain kinds of moulds. This may be overcome by
adding size water (which also hardens plaster) to the
gauging water. The setting may be regulated to any
required degree. Casts intended to be polished
should be covered with paper or cloths until dry,
and kept in a dry and warm place.

The following are the best known methods for
polishing plaster casts :— To 4 lbs. of clean water add
I oz. of pure curd soap, chipped and dissolved in a
glazed pot; next add li oz. pure white beeswax cut
into thin slices. \\'hen it is all properly mi.xed, it is
fit for use. The figure must be dried, and suspended
by a string. It is then dipped into the liquid varnish,
and when taken out, allowed to stand for about three
minutes ; stir up the varnish, and then dip the figure
again. Cover it up in a dry place, free from all dust,
for six or seven days, after which take some soft rag
or cotton wool, and gently rub the figure until it has
received a brilliant gloss.

Another 7<'(7y.— Plaster casts soaked in olive oil in
which white wax has been dissolved by heat, or casts

soaked in dissolved parafifin wax, will, when dry, take
a fine polish. The casts should be hot when put into
the hot solution. The polishing is done with French
chalk and cotton wool. If the polished casts are left
in a smoky room, they will acquire the appearance of
old ivory. Plaster casts can be made to assume any
colour by dissolving in the water for gauging any
desired colour in powder.

Another 7vay. — Soak the casts in a hot solution of
white beeswax and glycerine. When dry, polish with
French chalk and cotton wool or sable hair brushes.

Another way. — Take clean skimmed milk, and with
a clean soft brush coat the figure until it will absorb
no more. Ciently blow off all superfluous milk from
the face of the object, and lay it in a place perfectly
free from dust. When dry, it will have the appearance
of polished marble. A great deal depends on the
amount of care bestowed on the skimming of the
milk. Plaster gauged with milk and water will enable
the casts to be polished.

Another 7i>ay. — Plaster casts thoroughly dry and
brushed with two coats of clear linseed oil, and kept
for a while in a smoky room, will take a good polish,
and acquire the appearance of old ivory.

Another way. — Dissolve \ oz. of soft soap in i
quart of water, and then incorporate i oz. of white
wax. The ca.st is dipped in or brushed over with
this mixture. When dry, it may be polished with soft
rag and French chalk. Another way is to give the
cast a thin coating of white shellac, then paint over
this a good coating of boiled soft .soap, and polish
when dry with a soft dry rag.

Another way. — A beautiful varnish for plaster casts
may be made by fusing \ oz. of tin and \ oz. of
bismuth in a crucible. Melt together, then add \ oz.
of mercury. A\'hen perfectly combined, take the
mixture, allow it to cool, and add the white of an
egg. The casts must be dry, and free from stains or
dust.

Another 7vay. — The cast must be perfectly dry, and
free from scratches and dust. (Hve it a coat of linseed
oil, and allow it to stand until dry, after which give
another coat, and French polish in the ordinary way.
If a figure or bust is required to be white, make
smooth with white size, and varnish with hard white
varnish.

Another 7i'ay. — Take 2 parts stearine, 2 parts
Venetian soap, and i part pearl-ash. Grate the
stearine and soap, and mix with 30 parts of solution
of caustic potash. Boil this for thirty minutes, stirring
all the time. Add the pearl-ash dissolved in a little
clean rain water, and boil for five minutes. Stir until

Recipes.

565

cold, and mix with more ley until it is quite liquid.
Before use, it should be allowed to stand for a few
days, keeping it properly covered up. Let the figure
be clean and well dried. Coat with a soft brush or
sponge until the figure will absorb no more. Allow
it to stand well covered up, and give another coat.
When dry, rub with soft rags or a brush. This will
give a beautiful polish. The liquid may be kejJt for
years if properly covered up. Should the surface
not have the required degree of gloss, the operation
must be repeated. This liquid has the property of
hardening the plaster.

Another way. — Take a clean cast, well dried, and
coat with white wax. Place it before a fire until the
wax is absorbed. A good polish may then be
obtained by friction.

Another 7vay. — Plaster may be polished with French
chalk until it shines like glass. The cast when nearly
dry is dusted with the finest French chalk, and gently
rubbed with cotton wool. Repeat the dusting and
rubbing until a bright polish is obtained, taking care
that the chalk does not cake and injure the face of
the cast. ^Vhen perfectly dry, it may be dusted and
rubbed again to give a good finish. For deep parts
in a cast, where it is difficult to use the wool, use a
camel hair brush. French chalk can be used as a
help in the final polish in most of the other methods
described.

\V.\SHAHLE Pl.\ster Casts. — In 1S78, F. von
Dechend, of Bonn, obtained a patent for " making
plaster casts washable without injury." The process
consists of two distinct operations. One consists in
the application of a solution of borax and alum to
harden the plaster, and the finishing operation con-
sists in the application of insoluble precipitates, by
which the minutest pores are filled up and the
surface rendered hard. Salts of barium, calcium, and
strontium are suitable for obtaining insoluble precipi-
tates without forming spots. A method of performing
the process may be done as follows : — A hot saturated
solution of borax is spread with a brush over the cast
any required number of times ; next hydrochlomate
of barytes, likewise in the form of a hot solution, is laid
on with a brush, then soap solution is likewise applied
hot, any excess being removed with hot water.

Impervious Plaster Casts. — A mixture of 2
parts of fine plaster and i part of fluor spar powder
is gauged for the cast. When dry, it is rendered
impervious by coating with soluble glass.

Methods of Preparing Plaster Casts to Re-
sist THE Action of the Weather. — Brethauer's
method is to slake i part of finely pulverised lime to

a paste, then mix gypsum with lime-water, and inti-
mately mix both. From the compound thus prepared
the figures are cast. When perfectly dry, they are
painted with hot linseed oil, repeating the operation
several times, then with linseed - oil varnish, and
finally with white oil-paint. Statues, &c., prepared in
this way have been constantly exposed to the action
of the weather for four years without suffering any
change.

Jacobsen prepares casts which retain no dust, and
can be washed with lukewarm soap-water, by im-
mersing them or throwing upon them in a fine spray
a hot solution of a soap prepared from stearic acid
and soda lye in ten times its quantity, by weight, of
hot water.

Shellh.\ss recommends the coating of plaster of
Paris casts with a compound of finely powdered
mica and collodion prepared as follows : — The mica,
rendered perfectly white by boiling with hydrochloric
acid or calcining, is ground very fine, sifted and elutri-
ated, and then mixed with dilute collodion to the
consistency of oil-paint, and applied with a soft brush.
Casts coated in this way possess a silvery lustre, have
the advantage of being indifferent to sulphurous
e.xhalations, and can be washed without injury.

Plaster for Casting Metal. — Plaster mixed and
gauged with equal parts of powdered pumice-stone
makes a heat-resisting mould for casting fusible metals.

To Restore Plaster. — Plaster that has lost its
hard and quick-setting properties by dampness or
exposure to air may be partly restored and used for
gauging coarse stuff by boiling in an iron pot or pail,
keeping the plaster continually stirred with a stick or
iron rod.

To W.aterproof Plaster Work. — A solution for
protecting plaster exposed to the weather is composed
of 6 parts of linseed oil, boiled with one-sixth of its
weight of litharge, and adding i part wax. The
plaster surface must be clean and dry before the
solution is applied. It is laid on hot with a brush.
A warm dry day should be selected for using the
solution.

Plaster to Set Quick. — Plaster may be made to
set rapidly by adding alum. The alum should be
previously dissolved in water, and the alum solution
added to the pure water when gauging. Alum water
also increases the ultimate hardness of plaster. White
vitriol, dextrine, chloride of sodium (common salt),
sulphate of potassium, or gauging with warm water,
will quicken the setting.

Plaster to Set Slow. — The setting of plaster

S66

Appendix.

may be retarded by adding or gauging with size water,
ammonia, or stale beer. Sulphate of zinc added to
the water has also a marked effect in retarding the
setting and increasing the ultimate hardness of plaster.

To Cle.\n Antii.)Ue Plastkr C.\sts. — Old casts
that require to be carefully jireserved and cleaned car.
be restored by coating with a thin paste made cf
starch. When partly dry, peel it off.

To Cle.an Plaster Figures, Busts, &c.— Plaster
hollow casts soiled by dirt or dust may be in most
instances restored to their original whiteness. The
cast is inverted, and filled with clean water, free from
iron, and allowed to stand until the water has filtered
through the cast. The outside is occasionally washed
with water by the aid of a soft brush or sponge.

To Clean Keen's Cement. — One oz. carbonate
of poratta, i oz. carbonate of soda, i oz. Venus tur-
pentine, I jjint of warm water— all dissolved together.
Coat the object with the above solution, then with a
plaster padded flannel dipped in dissolved stearine
rub the object. This method may also be used to
clean plaster.

Semi-transparent Casts. — Beautiful casts for
plaques are made by gauging fine ground rice with
fine plaster in the proportion of one of plaster to three
of rice. Neat rice can be used for a thin coat on the
face, if gauged stiff, well pressed into the mould, and
allowed to dry. A hacking of the rice and plaster will
give further strength.

Japanese Casts. — Beautiful trans])arent casts can
be obtained by using fine ground rice in place of
plaster. The moulds must be quite clean, and the
cast allowed to set before it is e.xtracted. The rice
flour must be mixed intimately with cold water, then
gently boiled, and then poured into the moulds while
warm. A solution of rice, prepared this way, makes
an excellent paste. Papers pasted together by means
of this solution will sooner separate in their own sub-
stance than at the joining.

Modelling Composition. — Mix 200 parts of soap-
stone powder and 100 parts of the best wheat flour,
and stir the mixture carefully into 300 parts of melted
white wax, not too hot. This mass can be coloured
at pleasure.

American Modelling Wax.— Melt carefully over
a moderate fire 2 lbs. of yellow beeswax, add 4^ oz.
of Venetian turpentine, 2 oz. of lard, and 2J lbs. of
bole, and mix thoroughly. Then gradually pour the
mixture into a vessel with water, and thoroughly knead
several times with the hands. The wax should be
melted at such a low temperature that no bubbles
appear on the melted surface.

A.MERICAN P.ASTE COMPOSITION. — Mix together 13
parts of dissolved glue, 14 parts pulveri.sed litharge,
8 parts white lead, i part plaster, and 10 parts of very
fine sawdust. This composition is extensively used in
the manufacture of picture frames, and as a substitute
for carton-pierre, &c.

Statuary Markle Casts. — Figures, busts, or
other plaster casts or walls can be made to imitate
statuary marble true to nature. First gauge superfine
plaster with ground marble and white alabaster, and
to give greater lustre a small i)ortion of finely ground
white glass is added. White mica may also be used for
this purpose. The quantities depend on the tint of the
marble required. The general proportions are 2 parts
of plaster, i of marble (or marble and alabaster in
equal proportions), and \ part of glass. The moulds
are oiled with olive oil or paraffin oil and French
chalk. The materials are gauged middling stiff,
using a little clear size water in the gauging water.
This gauge is laid about \ inch thick, and then backed
up with neat gauged plaster. The casts can be
polished with Tripoli powder, French chalk, or by
some of the methods already given.

White M.arble Casts. — To produce plaster
medallions, busts, &c., with a white marble - like
appearance, mix from one-third to one-half part of
finely pulverised plate glass with one part of superfine
plaster. This mixture is gauged and poured into
the mould in the usual way. The mould must be
thoroughly clean, and oiled with salad oil or paraffin.
The casts, when nearly dry, may be polished by
dusting with fine French chalk, and then rubbing
lightly and quickly with cotton wool. If the moulds
are open so as to admit of the stuff being pressed, a
harder surface may be obtained by substituting super-
fine Parian or Keen's for the plaster. The casts may
also be polished by some of the other methods given.

Marbline Medallions. — To make a plaster
medallion look like marble, boil pure sweet milk, and
then skim it two or three times, pour it on the face
of the cast, and blow it evenly on all parts, taking
care that it does not get on the back ; lay it aside,
and cover it with clean white paper to protect it from
dust for two or three days, then put it in a shallow
dish face up, and pour in oil of sweet almonds until
it comes up to half or two-thirds of the edge of the
cast. Be careful that none gets on the face. As the
cast absorbs the oil, pour in more until it is saturated.
This makes the plaster perfectly transparent, and of a
beautiful colour. The milk forms a fine coat on the
surface which will bear washing.

Plaster Imitation Old Ivokv.— Ivorv carving

Recipes.

567

may be so closely imitated that onh' an expert can
detect the difference. Ivory carvings, or rather
castings, when mounted in metal, wood, or plush
frames, have been sold in great numbers, and at highly
remunerative prices, at exhibitions and art dealers'
sales. The process is simple, but requires a con-
siderable amount of skill on the part of the craftsman.
The moulds are generally taken from real ivory,
carving wood, or art metal work. Superfine plaster
is used. The water is tinted with fine yellow ochre.
For the general colour of old ivory, add | oz. to
each pound of plaster. When the casts are thoroughly
dry, they are dipped into spermaceti, and suspended
until the excess of the spermaceti has run off, and when
the cast is nearly dry, but still sticky, fine yellow ochre
is sprinkled on. The prominent parts are wiped with
fine rags or cotton wool. The success of the work
greatly depends on the art displayed in laying and
wiping the ochre. The ochre is dusted through a
fine muslin bag. Sometimes the grain or spots
(as seen in old ivory) is obtained by brushing,
stippling, or dabbing with small tool brushes having
the hair cut square, short, and wide apart. If the
cast is too large to be dipped, it can be brushed over
with warm spermaceti quickly and evenly, taking
care that the spermaceti does not cake. In both
methods the casts ,should be warm, and the ochre
ground to a fine powder. To imitate new ivory,
gauge with the tinted water, and when the cast is dry,
dip it for fifteen minutes into a solution of spermaceti,
white wax, and stearine in equal parts, then polish
with cotton wool.

Fictile Ivory (French process). — The cast is made
by gauging the plaster in the proportion of i lb. of
superfine plaster and h 02. of the finest yellow ochre.
They are thoroughly mixed by passing them through
a fine sieve, and then gauged with clean cold water,
to which a few drops of the best glue water have
been added. The cast is first allowed to dry in the
air, then carefully heated in an oven, and when the
cast is thoroughly dry, and still warm, it is soaked for
a quarter of an hour in a bath containing equal parts
of white wax, spermaceti, and stearine, heated a little
beyond the melting point. The cast is set on edge to
allow the superflous wax mixture to drain off, and
before it is cool the surface is brushed with a soft
tool brush to remove any wax that may have settled
in the crevices. When the cast is cold, it is finally
finished by polishing with cotton wool.

To Take Plaster Casts of Natural Objects.
— By this process, plaster casts of the most delicate
objects of natural history can be reproduced. The
material of the mould is modelling wax. As it becomes

soft and plastic by the application of heat, though in a
cold state it is perfectly rigid, it takes the most minute
markings and striations of the original to which it may
be applied without injuring it, and the microscopic
structure of the surface of the original is carefully
reproduced in the cast. This method is briefly this :
Cover the object to be cast with a thin powder of
steatite or French chalk, which prevents the adhesion
of the wax. After the wax has Isecome soft, either
from immersion in warm water or from exposure to
the direct heat of the fire, apply it to the original,
being careful to press it into the little cavities. Then
carefully cut off the edges of the wax all round, if
the undercutting of the object necessitates the mould
being in two or more pieces, and let the wax cool with
the object in it until it is sufficiently hard to bear the
repetition of the operation on the uncovered portion
of the object. The steatite prevents the one piece of
the mould sticking to the other. The original ought
to be taken out of the mould before the latter becomes
perfectly cold and rigid, as in that case it is very diffi-
cult to extract. Then pour in plaster, after having
wetted the moulds to prevent bubbles of air lurking
in the small interstices ; and if the mould be in two
pieces, it is generally convenient to fill them with
plaster separately before putting them together. Then
dry the plaster casts, either wholly or partially. Paint
the casts in water colours, which must be fainter than
those of the original, because the next process adds to
their intensity. The delicate shades of colour in the
original will be marked in the cast by the different
quantity of the same colour, which is taken up by the
different textures of the cast. After drying the cast,
steep it in hard paraffin. Cool and polish the cast by
hand and cotton wool with steatite.

White Cement. — The German (Government some
years ago offered valuable money prizes for a substitute
for plaster, or for a method of rendering plaster weather-
proof without destroying the original whiteness. A
great many inventors and chemists tried, but none
attained the desired result. It is now said that an
artificial white cement is manufactured in Germany
that has all the properties of Portland cement. It is
made by grinding 3 parts of fine chalk and i part of
kaolin, burning them at a red heat, and then re-
grinding. There certainly would be a large demand
for a strong white cement that could be used for
external plastering and for making artificial stone, and
while having all the properties of Portland cement,
would have a more pleasing colour. The native
carbonate of magnesia, magnesite, if originally of a
light colour, can be calcined at a low heat into a
white cement which is said to be stronger than

S68

Appendix

Portland ccmcnt ; but magncsilt- is a r.ire mineral,
consf(iUfntly the price of cc-ment made from it would
be prohibitory.

Wkatherproofing Plaster Casts. — Another re-
sult of the prizes offered by the German Government
are the two following experiments made by Dr W.
Reissig, of Darmstadt, in his endeavour to render
plaster casts washable, and at the same time to ])re-
serve the sharpness of outline.

He found this could be effected (i) by converting
the lime sulphate into baryta sulphate and caustic or
carbonate of lime, or (2) by changing the lime sulphate
into lime silicate by means of ])otash silicate. Of the
two methods, the former is preferable, being simpler,
more economical, and more easily carried out. The
lime sulphate is changed into baryta sulphate and
caustic lime by means of baryta water. Exposure in
the air subsequently changes the caustic lime into
lime carbonate. This is best worked by using a zinc
vessel with a zinc grating \\ in. from the bottom, and
a close-fitting lid, which must be nearly three parts
filled with soft water, 54 to 77' Fahrenheit. To every
25 gallons of water add S lbs. fusel oil or 14 lbs.
crystallised pure hydrated barium oxide, and 0.6 lb.
lime which has been slaked in water. The solution
stands about 4" Beck ( 1.024 1 sp. gr.). \\'hen the
baryta water is clear, the casts may be immersed, being
previously suspended by cords. The dipping should
be effected with rapidity. Hollow casts after being
saturated are filled with the solution and suspended
in the bath, and the vessel is closed from two to twelve
days, according to the .silicate stratum required. Then
remove the cover and the scum, draw the casts out by
means of the cords, rinse with lime water, drain and
wipe with soft rags. Do not handle them, and leave
ihem to drj' in a warm place. The solution can be
used again by adding more baryta and lime.

2. To harden by means of the silicate of potash
solution, convert the lime sulphate into lime silicate
by using a diluted solution of potash silicate contain-
ing free potash. Make a 10 per cent, solution of
caustic potash in water, heat to boiling point, adding
pure silicic acid (free from iron) as long as it con-
tinues to dissolve. After cooling the solution deposits
silicated potash and alumina. Leave it in well-
stoppered glass bottles to settle. Before using, throw
in some pieces of pure potash, or add about 2 per
cent, of the potash .solution. To indurate the casts,
dip them when cold for a few minutes into the solu-
tion, or apply it by means of a sponge. When the
chemical reaction is finished, remove the excess of the
solution by means of soap and water, and subsequently
rinse with warm pure water. When thoroughly dry,

the plaster casts can be washed with cold soap and
water, with the addition of oil of turpentine, taking
care that the sponge used be thoroughly clean. Then
rinse with clean water.

Glycerine Composition. — This is a mixture of
litharge and glycerine. Several other metallic oxides
may be mixed with the cement. The proportions vary
according to the consistency required, the proportion
of glycerine being greater for a soft cement. It sets
quickly, attains great hardness, and does not shrink.
It is used in Paris for producing blocks and plates for
printing and photoglyphic purposes. It is especially
adapted for moulding where extreme delicacy of lines
is required. Many other applications of this com-
pound are extremely useful. As a cement for joining
chemical apparatus it offers many advantages, for it
is unaffected by chlorine, hydrochloric acid, sulphur
vapour, sulphurous acid, nitric acid, and indeed resists
most corrosive vapours. Further than this, it with-
stands the solvent action of alcohol, ether, sulphide of
carbon, and all hydrocarbon vapours. It hardens in
fioni ten to twenty minutes if mixed of the consistence
of a thick dough, and sets under water as quickly as
in air. Moreover, it will stand a very much higher
temperature than any oil cement. The composition
may be also employed for moulds for electrotyping
and for casting metal work. F"or this purpose glycerine
must be stirred with the litharge until a mixture of
the proper consistence is obtained. The article to be
copied must be smeared with dilute glycerine before
the mixture is poured on, and plenty of time must be
given for it to set. ^Vhen used for casting metals, add
about 5 per cent of brick-dust to the mixture.

Acid-proof Portland Cement. — Portland cement
sinks or other castings are rendered acid-proof by
immersing them in a bath containing a solution of 10
parts vaseline and 7 parts of paraffin at 104° Fahr.
The casts should be thoroughly dry before being
placed in the baths. If they are slightly warmed, the
solutions will penetrate deeper, .^fter the first bath,
the casts .should be taken out, allowed to drip until
nearly dry, and then dipped again. Floors or other
large surfaces may be treated in a similar manner by
giving the surface from four to six coats of the hot
solution. The surface must be thoroughly dry, free
from dust, and the solution should be laid on with a
brush, taking care that no surplus solution is left on
the surface after each separate coat.

Greek Mastic. — This is made with i part of
shell lime and i of fine river sand, and gauged to the
proper consistency with skim milk and well beaten.

Aqu.\rium Mastic— This mastic can be used for

Recipes.

569

fixing glass tanks, and if the angles are filled in they
can be made without frames. It has also been used
for waterproofing brick walls. It is made as follows : —
Litharge, 3 parts ; white or silver sand, 3 parts ;
resin, i| parts; plaster, li parts, gauged with as
much boiled oil as will make the mass of a plastic
nature. The oil must not be added until required for
use, as it sets quickly.

Fireproof Mortar. — ^Two parts of the best lime,
and one part each of blacksmiths' ashes and brick-
dust, gauged with water or stale beer, as required.
This makes a good mortar for plastering round coppers
or fireplaces. It becomes as hard as iron.

W.\TERPRO0F M0RT.\R. — The lime is slaked with a
solution of green vitriol instead of water. The neces-
sary quantity of green vitriol is dissolved in warm
water, the lime slaked in the usual manner, and then
mixed with sand.

To H.\RDEN Lime and Cement \\ork. — Solutions
of sulphate of zinc, sulphate of iron, and sulphate of
copper are used for this purpose. The finished work
may be brushed over with these solutions, or the
mortar mixtures may be gauged with them. In the
latter case, the percentage of lime or cement in the
mortar can be considerably decreased.

Lime in the Eve. — Plasterers often get lime or
other foreign substances in their eyes when at work,
especially on ceilings, from splashes when gauging, or
in cutting down old plaster. The plan generally
adopted to clean the eye is for the half-blind plasterer
to stand steady while his partner squirts water from his
mouth into the injured eye, or licks the stuff out with
his tongue. The efficacy of sugar and water in allay-
ing the unpleasant smarting should be more generally
known. A chemical action is produced by the com-
bination of sugar and lime, which arrests the corrosive
effects of the latter substance. When sand or other
hard particle gets in the eye, most people rub with
one hand, meanwhile searching for their handkerchief
with the other. They sometimes do remove the sand,
but more frequently they rub until the eye becomes
inflamed. The better way is not to rub the eye with
the sand in it at all, but to rub the other one, and the
sand will soon work itself into the inner corner of the
eye. Do not attempt to take it out, but rubbing as
before, the sand will gradually run out on to the
cheek ; then wash the inside of the injured eye, or
squirt sugar water into it : dry it, and pour one or two
drops of olive oil in and around the eye.

Tracing Paper for Moulds, &c. — It sometimes
happens that tracings of drawings are required, and
when tracing paper is not handy, the following method

will prove a good and ready substitute. Damp
ordinary drawing paper with pure benzine, and the
paper (no matter how thick) will be as transparent as
common tracing paper. The design can then be
traced on it with either pencil or ink. The benzine
will soon evaporate, and leave the paper white and
opaque as before. If the design should not be
finished before the benzine has evaporated, it is only
necessary to damp it again. Paraffin oil may also be
used for the same purpose. The above is useful
for transferring moulding profiles when cutting mould
plates, (Sic.

To Mix Colours for ^'ARI0us Tints. — The
following mixings will be found useful for colouring
setting stuff, concrete, sgraffitto, gesso, stucco, dis-
temper, &c. Mixing black and red gives brown ;
white, yellow, and Venetian red gives buff; yellow
and white gives straw colour ; black, blue, and white
gives pearl grey ; green and white gives pea green ;
lamp-black and indigo gives silver grey ; lamp-black
and white gives lead colour ; light green and black
gives dark green ; red, blue, and black gives olive ;
yellow and red gives orange ; carmine and white gives
pink ; emerald green and white gives brilliant green ;
blue, white, and lake gives purple ; ^'enetian red and
black gives chocolate ; lake, white, and vermilion
gives flesh colour ; and mixing white and lake gives
rose colour.

To Paint Cement. — Caustic lime which is not in
a state of combination in cement saponifies .the oil
used in painting. Consequently painting on cement
is only practicable when, under the influence of the
air, carbonic acid has united with the caustic lime to
form carbonate of lime. Various expedients have
been resorted to in order to allow the cement to be
painted as soon as finished, but the best results have
been obtained by the use of casein. Presh white
cheese and fresh slaked fat lime are added to the
desired colour. This solution hardens rapidly, and is
insoluble in water, a formation of albuminate of lime
taking place. The solution, composed of 3 parts of
cheese and i of slaked lime, is well mixed, and the
colour added. Only earth colours, or oxides of iron,
should be used. Inorganic colours, aniline, Prussian
blue, and white lead should not be used. The caseous
lime should be prepared as required for daily use.
The mural paintings at the Berlin War Office were
done with this solution.

Oil paint on cement is likely to be thrown off by the
formation of crystals beneath it ; while, if it remains in
place, it usually presents a mottled appearance, owing
to the unequal absorption of the oil from the paint by
the cement. The common way of remedying both

3/^

Appoidix.

these tlifficulties has been to wash the cement surface
with acids before painting it. This dissolves any
crystals that may ha\e formed, and acts upon those
spots in the cement which have become slightly
carbonated by the action of the atmosphere, so as to
restore the absorbent quality, which the formation of
a superficial carbonate tends to diminish. Where acid
is used, it should be suljjhuric acid, made very dilute.
Muriatic and acetic acid, which are often emjiloyed,
leave the cemented surface impregnated with chloride
of calcium or acetate of lime, both of which are very
deliquescent, and by keeping the surface damp, pre-
vent the proper adhesion of the paint. A better
application even than sulphuric acid is, however, to
be found in carbonate of ammonia. The crystals of
the ammonia carbonate should be exposed to the air
until they effloresce partially into a white powder,
which is bicarbonate, and more .suitable for the pur-
pose than the original carbonate. About \ lb. of the
ammonia salt should be dissolved in 9 quarts of cold
water, and the cement surface washed with the solu-
tion. As soon as it is dry, the jiaint may be applied,
and will adhere well and resist the atmosphere. The
carbonate of ammonia is best applied when the cement
surface is about three weeks old. For prepared sur-
faces, perhaps older than this or more exposed to the
weather, silicate of .soda is sometimes useful. This
should be prepared by dissolving the syrup silicate of
soda of commerce in four times its hulk of water.
Three coats should be ap])lied, and after the last the
wall must be thoroughly washed to remove any signs
of silicate, or it will effloresce and throw off the paint.

Ad.\m.ant Colour. — Portland or Roman cements,
stone, brick, or wood can be coloured to any desired
shade by the use of adamant wash, which was origi-
nally made by G. Cox, a Chelsea plasterer. It has
been extensively used in London under various names.
The following are the quantities and materials for a
Portland stone colour, other colours being obtained by
using different pigments. Into a large clean tub pour
18 gallons of water, adding as much whiting as will
make it of the consistency of cream ; stir it well, and
pour in i gallon of linseed oil and i gallon of boiled
oil ; then mix 7 lbs of umber and 7 lbs. of yellow-
ochre with 2 gallons of turpentine, and pour into the
large tub. Add 6 firkins of size quite hot, and i lb.
of alum dissolved in i gallon of hot water. Stir all
together, and jjass the liquid through a fine sieve into
barrels. It is then ready for use. A])i)ly it with a
stock-brush. If the walls are old, two coats will be
required.

Cement Wash. — Cement wash is composed of
Portland cement and water. A small percentage of

putty lime is added where a lighter shade is required.
A solution of sul])hate of zinc is sometimes added to
give the wash greater permanency. Cement wash is
used for colouring cement or stucco facades, walls, (.\:c.

S.\NiT.\RV White\v.\sh. — Whitewash is one of the
most valuable sanitary articles in the world. Its
cheapness and easy method of a])plication bring it
within the reach of all. It prevents not only the
decay of wood, but conduces greatly to the healthi-
ness of all buildings, whether wood or stone ; out-
buildings and fences should be done twice a year.
There are various recipes for whitewash, but the fol-
lowing is one of the best. Into a large clean tub
put I bushel of lime, and slake it with boiling water,
covering it up during the ])rocess to keep in the
steam ; strain the liquor through a fine sieve ; then
add 3 lbs. of sulphate of zinc, i lb. of alum, and 2
lbs. of common salt, the alum and salt being pre-
viously dissolved in hot water. Various colours are
obtained as follows : — For a cream colour, add 3 lbs.
of yellow ochre ; pear or lead colour, add lamp, vine,
or ivory black ; fawn colour, add 6 lbs. of American
umber, 3 lbs. of Indian red, and i lb. of lamp-black ;
for stone colour, add 8 lbs. of raw umber and 4 lbs.
lamp-black ; terra-cotta colour, add 4 lbs. Venetian
red, 2 lbs. of purple brown, and 2 lbs. of yellow ochre.
Limewash with i lb. of coarse brown sugar added to
each 15 gallons of water, will adhere so firmly that
splashes on wood or iron will require to be scraped off.

Fireproof \Vhitew.\sh. — Slake freshly burnt lime;
add as much water as will reduce it to the consistency
of cream. To every 10 gallons of this liquid add 2 lbs. of
alum, 24 oz. of subcarbonate of potash or commercial
potash, I lb. of salt, and i lb. of plaster. The above
are added separately, and in the order named, being
constantly stirred. The whole is then passed through
a fine sieve. When required for use, it is heated to
boiling point, and applied in a hot condition. If the
wash is intended for old walls, the addition of a
small ((uantity of fine sand will tend to preserve and
strengthen crumbling walls.

A Che.\p Whitewash. — A good whitewash, that
will not peel or crack, is made by adding 1 part salt
to 3 parts stone lime. If used for granaries, sheds,
or where there is a difficulty in fixing scaffolding, it
may be quickly applied by using a hand fire-engine or
a large squirt.

A Brilli.^nt Whitew.\sh. — Take half a bushel of
good unslaked lime, and slake it with boiling water,
covering it during the process to keep in the steam.
Strain the liquor through a fine sieve, and add to it a
peck of clean salt previously dissolved in warm water, 3

Recipes.

5/1

lbs. of rice ground to a thin paste, and stirred and boiled
hot, \ lb. of powdered .Spanish whiting, and i lb. of
clean glue, previously dissolved by soaking it, and
then melting in a water bath. Add 5 gallons of hot
water to the whole mixture. Stir it well, and allow it
to stand for a few days well covered up to prevent
dust getting at it. The whitewash should be laid on
quite hot. This can be done by heating on a stove
as required. One pint of this liquid will cover a
square yard of surface. This whitewash retains its
brilliancy for years.

Mould-proof Whitew.vsh. — Whitewash when used
in cellars or dairies is liable to turn mouldy. This
may be prevented by adding i oz. of carbolic acid to
each gallon of whitewash.

Washable Whitewash. — Herr Reschenschek gives
the following (juantities to form a washable whitewash,
which, it is said, will not lose colour, and the hard-
ness of which will increase by wetting and wash-
ing. Mix 3 parts siliceous rock powdered, 3 parts
crushed marble or sandstone, 2 parts porcelain clay,
2 parts warm freshly slaked lime. This w-ill form
a wash, which in time will solidify like stone. Any
colour which can safely be used with lime can be
added to the ground colour. The wash is put on
thick, allowed to stand for a day to dry, then frequently
wetted with water, and it soon becomes waterproof.

LiMEWASH FOR Walls. — Reduce well-slaked lime
to a thin solution with water. Dissolve li lbs. of
rock alum in boiling water, and add cold to each pail
of limewash.

To Make Whiting. — Whiting is pure white chalk
ground to a fine powder. It is mixed with water and
size for whitening walls and ceilings. It is made as
follows : — Take 6 lbs. of whiting and just cover it
with clean cold water, let it stand for six hours, mix
it with one quart of best double size, and then leave
it in a cold place until it becomes like a jelly. It is
then diluted with water until of a thick creamy con-
sistency. One lb. of the jelly will cover six superficial
yards.

To Make Clearcole. — Clearcole is size, some-
times mixed with whiting or other colouring matter,
but generally it is size alone, and used as a priming,
or first coat, to stop absorption in plaster work.

Distempering. — Distemper, or destemper, from
tempera, a term used in fresco painting, is applied to
water-colours or pigments ground in water, beer, &c.
Painting scarcely comes within the category of plaster-
ing, but distempering (also whitewashing) was a part
and parcel of the plasterer's craft in ancient times.

Even at the present time this kind of work is done by
plasterers in many parts of the country, therefore a
brief description of distempering is here given.

The preparation of ceilings and walls for the
finishing in distemper is of vital importance to the
ultimate result, inasmuch as if they are not properly
prepared they will rarely turn out well at the finish.
The first thing to be done is to stop the suction, for
except the finishing colour lays on cool, and without
any or very little suction, the work is apt to be more
or less rough, and will gather or accumulate more
colour in one part than in another, and con.se(iuently
will look shady. And here the fact may be noted
which shows the necessity for the use of a preparation.
It will almost invariably be found that one part of a
wall or ceiling will have a greater power of absorbing
colours than another part. It will be observed, as
with a first coat of paint, that some parts are glossy,
and others dry dead, that is, the paint has sunk into
or been absorbed on the dead parts, while on the
glossy part it remains on the surface, owing to the
unequal finish of the plaster work. Of course, in oil
painting this is remedied by successive coats of paint.
It therefore becomes necessary that some means
should be adopted to stop this power of absorption,
and for this purpose various preparations are used.
The following has been recommended as a suitable
preparatory coat, and will be found to answer the
purpose very effectually. " Mix about 1 2 lbs. of the
best whiting with water to the consistency of soft
paste. Add sufficient parchment or other size to
bind the colour fast. Add about 2 oz. of alum, and
the same weight of soft soap dissolved in water. Mix
well together in a pail, and strain through a coarse
cloth or a metal strainer." Of course somewhat
similar proportions will answer for any quantity. The
colour should now be tried on paper, and dried
before a fire or otherwise, in order to test whether
sufficient size has been used to " bind " the colour,
and to prove that the tint is exactly what is reijuired.
The finishing coat can be laid on without disturbing
the first one. The alum and soft soap contribute to
this effect in a great degree, and help to form a semi-
impervious coating upon which the finishing coat will
work cool and without suction. Caution must be
observed not to have the size too strong, or it will be
very liable to chip, especially in rooms where much
gas is used.

In order to produce good work, two things are
essentially necessary in the mixing of the distemper,
namely, clean and well-washed whiting and pure
jellied size. The whiting should be put to soak with
sufficient soft water to cover it well and penetrate its
bulk. When the whiting is sufficiently soaked, the

57^

Appendix.

water should be ixiurcd ofi", which will remove an\-
dust or foreign matter from the whiting. It should
then be beaten up or stirred until all the lumps are
broken, and it becomes a stiff smooth paste. A good
workman will do this carefully with his hand, and will
manipulate it until it is quite smooth : but it may be
done most effectually with a broad stick or spatula,
and then strained through a metal or other strainer.
The si/e should now be added, and the two lightly
but effectually mixed together. Care should be taken
not to break the jelly of the size any more than can
be avoided, and this may be best done by gently
stirring the mixture with the hand. If the jellied
state is retained intact, the colour will work cool and
lay on smooth and level. Then size, whether made
of parchment clippings, glue, or any other material,
should be dissolved in a sufficient quantity of water
to form a weak jelly when cold. In practice it is
found that distemper mixed with jellied size will lay
on better and make a better job than when the size is
used hot. Colour mixed on the former plan works
cool and floats nicely, while the latter works dry, and
drags and gathers, thus making a rough ceiling or
wall, and the difference in the labour required is very
nmch in favour of the jellied size. A little alum
added to the distemper has a good effect in hardening,
and helps it to dry out solid and even. It is customary
in some cases to give the ceiling or wall a couple of
coats of oil paint previous to the application of the
distemper. This stops the suction and gives a rich-
ness to the colouring : but if, as frequently happens,
the wall gets low in temperature during a continuance
of cold weather, when a change takes place the con-
densation is so great that the water runs down in
streams to the top of the skirting, and the colouring
matter thereby becomes stained.

With regard to the method of laying on distemper
colours, it may be accepted as a fact that the sooner
they dry after they are laid on the better. The best
plan is to close the windows and doors, and stop the
free circulation of the air as much as jjossible while
the distemper colour is being laid on. This prevents
it drying too (juickly, and enables the workman to lay
the colour on more evenly and with less danger of
showing any pieces ; but the moment that the wall or
ceiling is covered, the windows and doors should be
thrown wide open, and as much fresh air admitted as
possible. This free circulation of air absorbs and
carries off the moisture from the walls. The evapora-
tion is quick, and a good job results. If the distemper
does not dry quickly, it becomes slightly discoloured
and shaded. One great point to be aimed at is, of
course, a level and uniform surface when dry, and this
desirable result can only be obtained by the colour

being laid on of a proper consistency, and with every
attention to equality.

When ceilings are badly stained and discoloured
from the accidental overflow of cisterns, water-closets,
iS:c,, the only effectual method of treating them is to
wash them off with clean water, and give two coats
of oil paint before the distemper is ai)[)lied. Other
processes are adopted, but as they cannot be depended
upon, it is much better, in the first instance, to incur
a little extra expense, and paint the discoloured ceiling
in oil colours.

The following hints for mixing various colours in
distemper, &c., by which at least a theoretical know-
ledge of the subject can he actjuired, which will greatly
facilitate progress in mastering the practical details,
are given by the author of the "Painter's and Grainer's
Handbook."

The best size for distemper colour is made from
parchment clippings. These are put into an iron
kettle filled with water, and are allowed to stand for
twenty-four hours, until the pieces are thoroughly
soaked ; then boil for five hours, occasionally taking
off the scum. \\'hen the liijuid is sufficiently boiled,
take it from the fire, and strain it through a coarse
cloth. If the size is to be kept for a length of time,
dissolve 3 oz. or 4 oz. of alum in boiling water, and
add to every pailful. The size must be boiled again
till it becomes very strong. It must then be strained
a second time, put into a cool place, and it will keep
for several weeks. It is cheaper and safer to buy size
ready-made from a maker of good repute.

Pink. — Dissolve in water separately whiting and
rose pink. Mix them to the tint required, strain the
colour through a strainer, and bind the size.

Lilac. — Take a small quantity of indigo, finely
ground in water, and mix it with whiting till it pro-
duces a dark grey ; then add to the mixture some rose
pink. Well mix and strain the colour, and a beautiful
lilac will he the result.

Light Grev. — A small quantity of lamp-black
mixed with whiting composes a grey- A wide range
of shades may be obtained from the darkest to the
lightest grey.

French Grev. — Take the quantity of whiting
required, and soak it in water, then add Prussian blue
and lake which have been finely ground in water.
The quantity of each of these colours should, of
course, be proportioned to the warmth of tint required.
This is a handsome and delicate colour for walls.
Rose pink may be substituted for the lake ; but it
does not make so brilliant a colour, neither is it so
permanent.

Recipes.

573

Orange. — This is a mixture of whiting, French
yellow or Dutch pink, and orange lead. These ingredi-
ents may be proportioned according to taste. This
colour cannot be worked except in a size jelly, as the
orange lead is a colour which has great density, and
will sink to the bottom, separating from the other
colours.

Buff. — A good buff may be produced by dissolv-
ing separately whiting and yellow- ochre in water. A
little English ^'enetian red should be added to give
a warm cast. Mix with size, and strain as before
directed.

Drab. — (i.) Dissolve whiting in water, and grind \
some burnt umber very fine in water. Mix to the i
tint required. Raw umber will make a drab of a
different shade. (2.) Dissolve separately some whit-
ing and yellow ochre in water. Take a quantity of 1
each, and mix them together. Grind a little lamp-
black very fine, and with it sufficiently stain the colour
to make the tint required. (3.) Another shade may
be obtained by adding a little Venetian red. By
diversifying the proportions of these pigments a great
variety of colours may be produced. These are all '
permanent colours, and may be depended upon.

Salmon. — An excellent salmon colour may be
made by dissolving whiting in water, and tinging it
with the best English Venetian red. A little Venetian
red, mixed with lime whitewash and a quantity of
alum, will answer tery well for common purposes.

Paints and Washes. — The following paints and
washes, which are extensively used in America, will
be found useful for various purposes : —

Flexible Paint. — Slice z\ pounds of good yellow-
soap and dissolve it in i^ gallons of boiling water, and
grind the solution while hot with 3I gallons of good
oil paint. It is used to paint on canvas.

New Paint for Floors, Stone, Plaster, Wood,
and Brickwork. — This new paint has the advantage
of saving oil and lacquer, being simply a combination
of glue, oil paint, and lime, and for w-ooden floors an
addition of shellac and borax. To prepare the ground
mixture, soak 2 ounces of good light-coloured glue for
1 2 hours in cold water, and dissolve it, with constant
stirring, in thick milk of lime (prepared from i pound
of caustic lime) heated to the boiling point. To the
boiling glue stir in linseed oil until it ceases to mix.
About 8J fluid ounces of oil is sufficient for the above
proportions. Too much oil is corrected by addition
of lime paste. Mix the above with any colour not
affected by lime, and dilute with water if needed.
For yellow-brown or brown-red colours, boil in the

ground colour \ of its volume of a solution of shellac
and borax, making an excellent paint for wooden
floors. The mixture is easily applied, covers w-ell,
and forms a durable combination with any covering,
and, as any desired shade can be produced by an
addition of proper colours, it may often be substituted
for more expensive paints. A simple coat of varnish
or lacquer gives a beautiful lustre.

Cheap and Durable Paint for Brickwork. —
Slake fresh-burnt lime to a powder by sprinkling w-ater
upon it, and pass the pow-der through a sieve. To
100 parts of this powder add sufficient w-ater to form
a thin milk of lime, and boil it in a copper boiler, and
add I part of bichromate of potassium. Make a thin
paste of sulphate of lead with water, and stir it in the
boiling mixture. Sugar of lead or the nitrate of hydro-
chlorate of lead can be substituted for the sulphate of
lead. Add cold water to the mass and pass it through
a fine wire sieve, drain it off through linen or cloth
bags, and press the residue remaining in the bags.
After sufficient pressing, break into pieces and dry in
the air.

To Prepare a Zinc Wash for Rooms. — Mix oxide
of zinc with ordinar)- milk of lime, and apply the mix-
ture in the same manner as whitew-ash. When dry
lay on a coat of solution of chloride of zinc. This
combines with the oxide, and forms a solid coat with
a lustrous surface.

Paint for Outside Walls. — Boil i pint of clear
linseed oil, 4J ounces of rosin, and 3 ounces of litharge
until die wooden spatula u.sed for stirring becomes
brown. Give the walls tw-o or three coats of this. It
is best to do the work on a hot summer day.

Red Wash for Brick Floors and Pavements. —
Wash the bricks with soap w-ater containing ^\j part of
carbonate of soda. This cleanses the floor and pre-
pares it for the reception of the wash. Then dissolve
X part of glue in 16 of boiling water, add 4 parts of
red ochre, and stir the mass thoroughly together.
Apply two coats of this to the bricks, and then give
a coat of linseed oil varnish.

Paraffin Paint. — A solution of paraffin in heavy
coal-tar oil is excellent for painting houses, and especi-
ally walls, exposed to the action of the weather.
Several experiments in painting damp walls with this
solution have given very satisfactory results. Wall-
paper, which formerly became moist and detached
from the walls during rainy weather, remained per-
fectly dry after the wall had been painted with paraffin
in heavy coal-tar oil. It is prepared by dissolving i part
of paraffin in 2 to 3 parts of coal-tar oil at a moderate
heat. A sufficient quantitity of oil must be used, so

=i74

Appendix.

that the solution docs not entirely congeal on cooling.
To heat the paint while applying it, place the vessel
containing it in hot water. It is best to apply the
solution on a warm day, when the bricks are dry.
Generally one coat is sufficient, but even if two coats
are given, the cost is considerably less than oil
l)aint.

(Jimcklv-Drving Oil 1'aint. Boil for 15 minutes
in an earthenware pot i part of soft curd in 3 parts of
water. Pour the mass through a colander, wash it
with cold water, and press out the water in a linen

cloth. To I part of the curd add \ part of unslaked
lime and \ part of water. 'I'he fat slime thus formed
is triturated in oil or water with the various jjigments.
Walls, ceilings, stairs, in short anything of stone,
plaster of Paris, or zinc, can be i)ainted with this. If
the paint is to be used on wood, add ^^ ])art of lin-
seed oil. Ochre, chrome yellow, Berlin blue, indigo,
lead, and zinc are best adapted for colouring sub-
stances. The mixture dries so quickly that three
coats can be applied in one day. It is entirely with-
out odour, and costs about niu-4hird of ordinary oil
paint.

III.— GLOSSARY OF ARCHITFXTURAL AND PLASTIC TERMS.

Abacus, the top moulding of a capital. The word
is tkrivLcl from the Greek word abax.

AcanthuSj a plant popularly named Bear's Breech,
whose leaves are used for decorating the Corinthian
and Composite capitals. Parsley and laurel leaves are
also unliI for the same puqwse.

Acroteria, the small pedestals at the extremities
and apex of a pediment. They were originally in-
tended to support figures. They are sometimes called
Pinnacles. The word is Greek, and signifies "the
extremity."

Aggregate, the literal meaning is the conjunction
of many particles held or bound together by the
matiis.

Angle, the arris or edge, salient or receding,
formed by the conjunction of two surfaces not in the
.same plane.

Angle-bead or Angle-staff, a round member at
exterior angles, formed by plastered surfaces.

Arch, an arch is a structure composed of separate
inelastic bodies, having the shape of truncated wedges,
and the vertical forces due to the weight of the mate-
rials are transmitted to the supports or abutments in
a curved line, known as the curve of equilibrium. It
is a support to the superstructure, and is either circu-
lar or elliptical. The arch is the most important
discovery in architecture. When or where it was
invented is uncertain.

Architecture, the science which teaches the art
of constructing buildings for the requirements of
mankind. The design of a building is generally laid
out in three parts. The first is the plan, which shows
the extent, division, and distribution of the ground
into apartments, tS:c. The second is the elevation,
which shows the various stories, their heights, and
the outward appearance of the whole building. The
third is the section, which shows the inside or centre
parts. There are five classic orders — the Doric,

Tuscan, Corinthian (Greek), Ionic, and Composite
(Roman).

Table XXV. — Beginning and Duration of thk
MORE Modern Styles of English Architecture.

N.ime.

Norman -

Early English

Decorated

Perpendicular

Elizabethan -
Jacobean - -
(2ueen Anne -

Prevailed.

1066 to 1 154

1 189 to 1272
1307 to 1377
14S7 to 1547

1558 to 1600
1603 to 1702
1702 to 1760

General Characteristics.

Round-headed door-
ways and windows,
heavy pillars, and
zigzaj.; ornaments.

Narrow pointed win-
dows, clustered pil-
lars.

Geometrical tracery
in windows, en-
riched doorways.

Upright lines of
mouldings in win-
dows, and doorways
often a combination
of square heads
with pointed arches.

.\ species of Perpen-
dicular ; enriched
interiors ; strap-
work ornaments.

Admixture of classic
and Gothic, with
beautiful and ela-
borate interiors.

Free classic treat-
ment, quaint mould-
ings and ornament.

I'ure Gothic was first introdnceil in 1272.

" Transition " is a term applied to the interval
which elapses between one style and the full develop-
ment of the next. It is usual to allow the period of
about twenty-five years for the change of one style
to the other.

Architrave, the lowest member of the entablature,
and is composed of one or more faces, according to
the order.

Glossary.

3/3

Archivolt, the nicmlding round an arch.

Arris, the external angle or edge formed by the
mcrting of two planes or curved surfaces.

Artist, a skilful man in arts and crafts ; not a
novice.

Astragal, a small round moulding which encircles
the top part of the shaft of a column, and separates
the shaft from the capital. The astragal is also
termed a talon, and is cut into beads, and used in
decorated entablatures to separate the faces of the
architrave.

Axis, the line, real or imaginary, that passes through
anything on which it may revolve.

Baluster, a small round or square pillar or pilas-
ter, serving to support a rail or cornice, generally
ornamented with mouldings or other decorations.

Balustrade, a connected series of balusters sur-
rounding balconies, terraces, parapets, steps, stair-
cases, tops of houses, &c. They are sometimes used
solely as ornaments.

Band, a flat, low, square profiled member.

Base, the lower part of columns, pedestals, &c.

Bas-relief, a model or cast in which the figure
or figures do not project in full from the ground.
There are three kinds of reliefs, which are usually
termed the flat relief {basso-7-elievo) ; the high relief
(alto-relievo), which shows the figures standing well
out from the ground : and the mezzo-relievo, which
gives the half-raised figures. Each relief has many
intermediate shades or heights.

Bay, in plastering, is used in a compound form.
A bay of plastering is the part between two screeds,
mouldings, or beams.

Bay Window, a bow window, one projecting
beyond or from the general surface of the building.
It is usually of a semi-polygonal form, and some-
times semicircular or semi-elliptical. An oriel window
is similar to a bay, but does not descend to the
ground, and is suspended over the face of the wall
beneath it.

Bead, a small member of a semicircular form.
It is sometimes cut or modelled in a globular form,
either close together or slightly apart, and connected
by a small stem running through the centre. This
form is commonly called a "bead and reel."

Bead and Quirk, a bead on the edge of material
flush with its surface.

Bed Moulding, the term is generally applied to
the mouldings in all the orders between the corona
and frieze. They are usually enriched.

Bell, the inverted bell or drumlike ground on
which the leaves and other enrichments of a capital
are placed.

Bevel, any angle except one of 90'. Anything

that is not square is generally called a bevel angle,
whether it is more obtuse or more acute than a right
angle.

Blister, a scaly protuberance on the surface of
plaster work, caused by the blowing or bursting of
improperly burnt or slaked lime, or by the presence
of foreign matter.

Blub, a trade term for holes in moulds, casts, and
plaster work, caused by contained air and careless
manipulation of the materials.

Boning, the operation of levelling by means of the
eye. It is performed by placing two parallel straight-
edges on an object, and sighting on their upper edges
to see if they range. If they do not, the surface is
said to be "in wind" or "winding."

Boning -rods are used for boning. A boning-rod
is made in the shape of the letter T. The head gives
the sighting point.

Boss, a Gothic enrichment. It is used at the
intersections and ends of Gothic mouldings.

Bracket, a skeleton support for plaster mouldings,
also tor ^a\ing materials. Brackets are made of
wood (and in a few instances metal), and are sawn
to the required contour and nailed into position.
They form a basis for the lath and plaster, or fibrous
plaster, slabs, panels, or large mouldings used in the
formation of arches, domes, beams, sunk panels,
columns, <S:c. In domed work, spherical bracketing
is the forming of brackets to support plaster work,
so that the surface of the plaster shall form the
surface of a sphere. Spheroidal bracketing is the
bracketing prepared for a plaster ceiling, whose sur-
face is to form that of a spheroid. The word bracket
is also used for an ornamental tapered truss or
support.

Bust, a portrait statue of a [lerson. A liust com-
prises the bead, shoulders, and breast. Lysistratus,
the sculptor, is cited as the inventor of busts. &c..
cast from moulds, B.C. 328.

Camber, curved upwards to the centre to com-
pensate for settling, as in a beam or a lintel.

Cantilever, the same as truss, but the term is
generally used where the projection is greater than
the length, for instance a truss supporting a balcony.

Capital, the head or top part of a column or
pilaster. It generally consists of three parts. The
first is the astragal or necking ; the second is the bell,
which is enriched with foliage, scrolls, &c. ; and the
third the abacus, which is the top or finish of the
capital.

Carcase, the naked shell of a house without floors
or plastering.

Caryatides, female figures serving as columns or
pila>ter> to ?upi)ort entablatures, &c. Male figures for

576

Appeniiix

the same puriiose are termed IVrsians, Atlantes, also
Telamones. They were only employed by the ancients
where |)illars were too insii^nificant for the erections.

Case, a i)laster frame to keep the various parts of
the moulil in position.

Cast, an (ibjeit producrd fnini a mould.

Cauliculus or Caulicoli, the volutes or scrolls
uniier the abacus of a ca])ital.

CavettO, a hollow member of a moulding, whose
profile is a ([uadrant of a circle.

Ceiling, in architecture, is the plaster or other
covering at the to|) or upper surface of a room upon
the under side of the joists. An inner roof.

Cement, in building, is an artificial compound
forming a hard, strong, and binding plastic mortar.

Chamfer, to cut off to a sloping edge, the arris
rut or ^pl,lyed.

Chord, a line in a circle connecting the two ends
or S|)ringing I'f a circle or arch.

Cinque-cento, a term generally architecturally
applied to the revival of art coeval with the Early
Tudor style in England and the Renaissance style in
Erance.

Cinque-foil, an ornamental foliation or feathering,
used in the arches of the lights and tracery of windows,
panellings, ^tc.

Clay, a name given to hydrous silicates of alumina
derived generally from the decompositions of some of
the older rocks. These are slate clay, fire-clay, plastic
clay, China or ])orcelain clay, common clay or loam.
.S|)ecific gravity, 2.0.

Coat, a stratum or thickness of plaster done at one
time.

Coffer, the space in the soffit lietween the mo-
dillions, often containing round or square patera.
Coffers are generally used in the five orders, the
Tuscan excepted. The term is also used for deep
sunk square panels in flat or arched ceilings.

Concave, hollow, the op])Osite to convex.

Concrete, to " concrete " means to coalesce into
one m.i^-.. In Erance it is termed bitten.

Console, a Erench term for a truss or support.

Contour, outline or profile of any member,
moulding, or bodv.

Convex, rising in a circular form, the opposite to
C(_)nrave.

Core, the inner part of a capital or other large
body on which the plaster or cement is run. The
core is . to save materials and weight, and also to
prevent an unnecessary body of plaster, which would
cause undue swelling or expansion.

Cornice, a projection consisting of several mem-
bers which crowns or finishes an entablature, or the
body or wall to which it is annexed.

Cove, a hollow cur\ed member or space in a
moulding, above, below, or between mouldings. A
cove may either be plain or enriched.

Crocket, a C.othic ornament which creeps up
mouldings.

Cusp, an ornament in the Gothic and Saracenic
styles. It consists of projecting points formed by tlie
intersections of curves of mouldings.

Cylinder, a circular wood frame, lathed and plas-
tered, to form columns or other circular work.

Dado, the lower part of a wall, or space between
the base and surbase.

Datum-line, the horizontal line of a section from
whirh all heights and depths are taken or calculated.

Daubing, an ancient term for rough plastering.

Dentils, small oblong square blocks used in the
bed mouldings of the cornices in the Ionic, Corinthian,
Composite, and sometimes the Doric orders. Their
breadth should he half their height, and their intervals
two-thirds of their breadth.

Dubbing or Dubbing-out, a mode of bringing
a hollow or une\en surface to a fair one, to receive
the usual thickness of plaster work. It is accom-
|)lished by fixing pieces of tile, slate, bricks, or lath
witli gauged coarse stuff, cement, or nails.

Dutch-rush, a fine fluted reed having a sharp
file-like surface. It is used for taking seams of casts
and for cleaning up plaster and cement cast work. It
is superior to glass paper, as it is not so readily
affected by damp. It is also used for wet polishing
plaster, cement, and wax.

Egg-moulding, is the ovolo or quarter round,
enriched in the form of an egg and dart, or sometimes
an egg and anchor, or a tongue. It is said that the
egg signifies life, the dart death, the anchor hope, and
the tongue s]ieech.

Eiorchee, or Anatomical figure, signifies the
subject man or animal deprived of its skin, so that
the muscular system is exposed for the purpose of
study.

Ellipse, a part of an oval, a curve produced from
two or more centres.

Entasis, the swelling in the shaft of a column.

Facade, the face or front of a building.

Fascia, a flat member or broad band, generally
used in the architrave of the more elegant orders.
They are divided into three bands ; the lower called
the first fascia, the middle one the second, and the
upper one the third fascia.

Fence, a clay, plaster, wood, or metal guard to
enclose a mould or cast, to prevent the escape of wax
or other liquid material.

Fillet or List, the small square member placed
above or below the various S(|uare or curved members

Glossary.

S77

in an order or cornice. Wood fillets are strips of
wood generally about i^ in. wide, i in. thick, and in
various lengths.

Finial, the ornament which forms the external
termination of a Gothic pinnacle or other point.

Fish-skin, the dried skin of the dog-fish. It is
durable and resists damp, therefore useful for smooth-
ing and polishing wet surfaces.

Flush, a term used to signify a continuity of surface
in two bodies joined.

Foliage, ornamental scrolls or lines formed with
stems, branche.s, and leaves. The serrations of orna-
mental leaves are termed lobes.

Fret, from a term used in heraldry. An enrichment
consisting of one or more bands, generally straight, and
forming various squares and parts of squares.

Frieze, the middle member in the entablature
which separates the architrave from the cornice. In
the Tuscan order it is always plain ; in the Doric it is
enriched with triglyphs ; in the Ionic it is sometimes
swelled ; in the Corinthian and Composite orders it
is enriched with figures or foliage. The term is also
applied to decorated longitudinal wall surfaces.

Furr, a white scaly lime substance which often
forms on the surface of moulds.

Furring, nailing wood fillets on joists and rafters
to strengthen them, or to make the surface straight
and level to receive lath and plaster or fibrous slabs.

Gargoyle, a grotesque Gothic ornament, generally
used as an outlet for water.

Gauging, the accurate gauge of quantities, and
the pr()])er mixing of different materials.

Glyphs, the vertical channels in the triglyphs of the
1 )oric order.

Groin, the line formed by the intersection of two
arches which cross over each other at any angle.

Groined Ceiling, one formed by three or more
curved surfaces, so that every two or more may form
a groin, all the groins terminating in one point.

Groined Vaulting, a vault which is formed by
groins springing from various points and intersections.

Grounds, the plaster surface on moulding pieces
for moulding purposes. In carpentry, pieces of wood
fixed to walls and partitions, with their surfaces flush
with the plaster, to which the facings or finishings are
attached.

Guilloche, an ornament somewhat like a fret, but
having two or more bands turning over or interlacing
with each other, so as to repeat the design.

Gypsoplaste, a cast taken in jjlaster.

Gypsum, sulphate of lime, called plaster of Paris,
also "plaster" after it is calcined.

Helix, the small volutes under the abacus of the
Corinthian capital.

Hexagon, a figure having six sides.

Hexastyle, a building having six columns in front.

Hollow, a term in architecture, sometimes used for
a concave member.

Impost Moulding, the horizontal moulding along
the tops of piers (where the arch springs from); the
moulding round the arch is called the archivolt.

In situ, in the permanent or original situation.

Jerry - builder, jerry -work, a cant term for a
scamper, or scamp work. The term originated
from a firm named Jerry Brothers, builders, who
carried on work in Liverpool in the early ])art of this
century. This firm gained an unpleasant notoriety
for rapidly building showy but ill-constructed and
insanitary houses with cheap labour and materials.
The equivalent for " jerry-builder " in America is
Buddensick, a builder who used to run up gaudy and
flimsy houses in New York. In Germany the jerry-
builder is known as the " Bauschwindeler."

Joggle, the joint of two bodies constructed with
corresponding raised and sunk parts, to prevent them
sliding past each other.

Key-Stone, the centre or highest stone in an arch.

Matrix, derived from the Latin, its literal meaning
being a mould in which anything is formed. It is
also used to designate any cementing material.

Model, the original from which a copy or a mould
is taken : also a pattern, usually on a small scale, of
work which has been or is to be done.

Modeller, one who designs and makes models in
clay, plaster, wa.x, &c.

Modelling. — The forming of figures, models, and
works of art, from which copies are to be reproduced ;
also modelling figures and ornaments direct in the
final material, such as terra-cotta, clay, which is sub-
sequently baked), plaster, cement, gesso, &c., either
in a studio or in situ. The invention of the art of
modelling in clay is attributed to Dibutades, the
Corinthian, about 985 B.C. His daughter traced the
profile of her lover, by his shadow on the wall, and
her father filled up the outline with clay, which he
afterwards baked. Had Pliny known more of Egypt
and Phcenicia he might have made a more accurate
statement, as shown in Chapter VIII. Vases, pots,
&c., had been made in rude resemblance of faces,
figures, and foliage, for unknown ages past.

Modillion, also termed Block, an ornament like a
small bracket or console, used beneath the corona of
the richer orders.

Module, a measure of proportion, the lower
diameter of the shaft of a column.

Mould <ir Matrix, a reverse pattern of a model in
which a cast is formed. A " running mould " is used
to run or form plastic mouldings. A " reverse running

57«

Appendix.

mould " is used to form a casting mould. A " reverse
casting mould " is one made without the aid of a
model, hcinu made the reverse of a model.

Mouldings, those parts of an order wliich are
composed of various curves and squares. The parts
are often teriiud members.

Moulding -piece, a model or original witii a
ground, or otherwise constructed to mould from. In
some parts it is called a ''solid."

Niche, a square or circular cavity in a wall or
other siilid. It i^ from the Italian Nici/ia, a shell.

Oblique Angle, an angle that is greater or less
tiian a right angle.

Oblong, a rectangle of unequal dimensions, a
figure longer than broad.

Obtuse, anything that is blunt, the opposite to
acute or Nharp.

Ogee or O.G., the same as Cyma.

Ogives, arches or Gothic vaults which, instead of
being circular, pass diagonally from one angle to
another, and form a cross between the other arches,
making the side of the squares. The centre or inter-
section is called the key, and is generally covered
with a boss or [jendant.

Original, a first design or model. The term is
also applied to a moulding piece.

Pediment, the triangular crowning ornament of the
front i)f a building, or of u door, window, or niche.

Planting, fixing any part of a moulding or an
ornament on the main part of the work.

Plaster, in Old English written plaister from before
1745 to as late as 1783; Greek, (/i-Xturrpov ; Latin,
Emplasintm ; French, Platre. A term loosel)- applied
to any form of gypsum, cement, or mortar. A
common name for calcined plaster. To Plaster,
to overlay or cover with ])laster, to render fair unequal
and rough surfaces, to hide defects.

Plasterer, one who plasters or overlays the car-
case or skeleton of a building, to form plumb, level,
smooth, and hard surfoccs ; one who forms plastic
mouldings, enrichments, and figures. "Thy father
was a plasterer " (Shakespeare). " The plasterer doth
make his figures by addition " (Sir H. Wotton).

Plasterers' Work or Plastering, French,
Chape . ( lerman, Ueherschutt {Lukiitm or Turkish
plaster). Work composed of plastic materials exe-
cuted by plasterers.

Plasterly, resembling plaster. " Out of gypseous
or plasterly grounds" (Fuller).

Plastery, of the nature of plaster.

Plastic, in Greek, -Xao-TiKos; Latin, Plastiais ;
French, Plastique, fit for moulding. A combining
form signifying developing, forming, growing, as hetero-
plastic, monoplastic, polyplastic ; having the power to

give form or fashion to a mass of matter, as " The
plastic hand of the Creator" (Prior); "See plastic
nature working to this end " (Pope). Capable of being
formed or modelled as clay, plaster, or cements ; per-
taining to or characteristic of modelling, moulding ;
said of sculpture and the kindred arts, in contra-
distinction to painting and the graphic arts. " Medal-
lions . . . fraught with the plastic beauty and grace
of the palmy days of Italian art " (J. S. Harford).

Plastography, the art of forming figures in plastic
materials.

Plinth, the square solid part under the base of a
column, pedestal, or wall.

Plug or Dook, a wedge-shaped piece of wood
driven into the wall, as a means for fixing wood or
fil>rous jilaster.

Profile, the contour of the different parts of an
order or moulding, &c.

PuttogS, pieces of timber about 7 ft. long, princi-
pally useil for outside scaffolds.

Quirk, the recessed or sunk part placed at the side
of a bead or moulding, much used in Gothic archi-
tecture. In Grecian architecture ovolos and ogees are
usually quirked at the top, and sometimes in Roman.
A " double quirk " is when both sides of a bead or
moulding are recessed.

Quoin, the square or rectangular stones or projec-
tions at the exterior corners of a building. They are
generally disposed in the way known as " longs and
shorts," a short one between two long ones.

Rabbit, a channel or groove, an overlapped joint.

Radius, the straight line drawn from the centre to
the circuniferenre.

Raffling, the serrated or notched edges of leaves
or foliage.

Renaissance, the name given to the style which
revived the forms and ornament of Roman and
Grecian arts. It was commenced by Italian artists of
the fifteenth century. The style is called " Cinque
Cento " in Itah', and " Elizabethan " in Cireat Britain.

Rims, of casts, the bearing or fixing parts.

Rims, of moulds, the ruling-off edges.

Rococo, a debased Renaissance style of the time
of Louis XV. and X\T.

Rose, the round flower placed in the centre of
each side of the Corinthian capital ; a circular orna-
ment ; a flower.

Run-down, mouldings that are run on a board or
a bench for lixing purposes.

Rustic, courses of stone left with jagged or irregu-
lar surfaces.

Septaria, the petrified e.xcreta of e.xtinct animals,
found in nodules in various parts, and used in the
manufacture of Roman and similar cements.

Glossary.

579

Setting, the quality that any material possesses of
getting hard in a short time. The term is also used
for the finishing coat of plaster work.

Soffit, from the Italian Soffilo, the under part of
the corona ; also the under part of ceilings, doors,
arches, stairs, iS:c.

Solid Work, a modern trade term used to dis-
tinguish lime or cement plaster work laid on walls or
ceilings from fibrous plaster work.

Spaced Ornaments are those fi.xed with a space
between tlK-m.

Spandrel, spaces, either plain or enriched, between
an arch and the square formed round it ; also the
space between a circle and square angle.

Stairs are of various kinds, as straight-fliers,
square-fliers, triangular-fliers, winding stairs, and
mi.xed stairs.

Stopping, the filling up and making good small
cracks ur uthcr defects in plaster or cement work.

String Course, a horizontal projecting moulding
in .1 wall.

Suction, the tendency of any porous material to
absorb moisture.

Tempered, a term used to denote the mixing of
plastic material, ^\'ell-tempered stuff' means that the

materials are thoroughly incorporated and in a plastic
state by being projjerly mi.xed and worked.

Tensile Strength, the resistance to extension or
stretching.

Torso, in sculpture, is a body without arms or legs.

Torus, a moulding of semicircular form usi-d in
the bases of columns.

Tympanum, the space enclosed by the cornice of
the siili-s ijf .1 pediment, and the level fillet of the corona.

Volute, the scrolls at the angle under the abacus
of capitals. In plasterers' parlance they are called
" horns."

Voussoirs, the stones that form an arch.

Weathering, a splayed surface to allow water to
run ofif.

Well of a Staircase, the enclosed or open space
reaching from one floor of a building to another, in
which the stairs or staircase is erected.

Well-hole, in a flight of stairs the space left in the
middle, beyond the ends of the steps.

Winders, those steps of a stair which, radiating
from a centre, are narrower at one end than the other.

Zero, the commencement of a scale marked o, or
nothing. It usually denotes the point from which the
scale of a thermometer is graduated.

IN DEX.

A BACUS, use and position of the, 524
■^^- Acanthus leaf, the, 298
Acanthus mollis, the, 529
Acid-proof Portland cement, 568
Acroteria, use of, 452

Act passed to fine non-members for plastering, 548
,, restricting plasterers from painting, 30
Adam, Robert, ceiling by, 34

his influence on plaster work, 22
his st)le, 2,7,
Adamant cement, 76

,, covering capacity of, 555
Adhesive strength of limes, 44 ; Portland cement,

S°3
Adie's cement testing machine, 59
Adjustable calipers, 235
Adulteration of materials a penal offence. 549

evil effects of, 105, 549, 551
Affinity of Portland cement, 465
Aggregates, 460, 461, 462, 463, 464

bad, spoil good matrices, 471
,, care in selection of, 462

compound, 462, 470
fireproof, 463
,, form of, 461, 462

graduating sizes best, 462, 464
„ importance of being angular, 461

„ meaning of the word, 460, 574

porous, 460, 461
Air-slaking Portland cement, 63
Aitchison, Professor, on ancient plastering, 230
Akbar Mirza, Persian architect, designs by, 426
Alabaster, 35
Albert! on lime, 45
Alburium, stucco, loi, 102
Alcazar, plaster work at, 431
Algiers, plaster work at, 424
Alum for casting in jelly moulds, 331 ; fibrous plaster,

339; jelly moulds, 319; setting plaster, 331
American composition, 566

experiments in substitutes for ox hair, 51

American experiments with sugar in cement and
mortar, 48, 49
„ modelling wax, 566
„ patent plasters, 84
Analysis and cost of labour and materials for plaster

work, 559
Analysis of hydraulic limes, 40
,, Portland cement, 57

.Ancient concrete at Peru, 457 ; Rome. 456
,, lath and plaster. 4
„ lime plaster, i
,. plaster floors, 2

moulding from life, 2, 7.
pavements, 2, 4

statue of Apollo, 6; Bacchus. 3
work at Hadrian's Villa, 230 : Greece,
2, 230 ; the Pyramids, i : Peru. 457 ;
Pompeii, 5, 6, 230; Rome, 5, 230:
the Temple of Apollo. 230
work for damp wails. 4
stucco, 2, 3, 4. 5, 6
„ three-coat work, i
tools, 537
Anderson's silicate cotton, 373
Angelo's, Michael, use of the pouncing process, 237
Angle brackets, to set out. 522
degrees of, 521
.. float, the, 538

internal and external, 98, 100
piece, Austrian, 446
,, trowel, 546
.Anglo-Saxon plaster work, 14
.Annulets, position of, 528
Antefix, terra-cotta, 452
Appendix, 555
Apprentices, good, 549

„ importance of study by, 347

London, 549
„ seven years', 28

,, the Plasterers' Company and. 548

I .Apprenticeship, general system of, 551

58;

Index.

Apollo, ancient plaster statue of, 6
Arabesques, Alhambra, 429

Damascus, 4:2, 424
created by the Moors, 428
method of setting out, 429
Arabian architecture, 420

I)ancl, 425
Arch, O.G., to describe, 520
,, radius running mould, 313
,, to find the centre of an, 518
„ to set out a flat, 518, 519
moulded, 519
pointed. 519
„ semicircular, 519
Arches over arches in facades, 203
Architectural model making, 247
Architecture, elements of, 522

orders of, 527
Architraves, window, 208
Archivolt mouldings, to run, 3 1 3
positions of, 533
„ proportions of, 533
Arden lime, 39
Arms, plasterers' coat of. 250
Arnold's sand, 53

Arnoldin, M., ornamental plasterer, 438
Artificial marbles, 409
stone, 505
„ „ strength of, 494

Asbestic plaster, 78

Aspdin, inventor of Portland cement, 55
Astragal, use and position (jf the, 523
Audley End, plaster work at, 16. 31
Austrian Government, interest in |)laster work, 447
,, plaster work, 446

Portland cement, 62
„ stucco, 446

D.ACCHUS, coloured >tucco statue of, 3
'-^ Baggutti, ornamental plasterer, 20
Balcony fronts, 333, 334, 338, 339
Baldwin, G., foreman plasterer, 238, 398
Ball oil-pot, 280

Ballard, Dr. on concrete paving, 477
Balusters, 534

cast, 274

distance between.

3J3

model making for, 271
jjlaster piece moulding, a, 272
the five orders of, 534
Balustrades, cast, 204

„ constructing, 204, 205, 206

formed in situ. 204, 206

Balustrades, pierced work for, 207
ramped, 534

setting out, 203, 534, 535
Barrow hydraulic plaster, 8 1

Barry, E. M., judging effects of enrichments, 228
Bassett's plaster, 77
Bead, to describe, 526
Bed-moulds, position of, 524

„ wax moulding, 255

Beeswax, 247

Belgian and British plaster work, 447. 44S. 449
,. fibrous plaster, 447, 448
,, plaster work, 447
,, plasterers, 447, 448
Bcton agglomere, 458, 459
Bench slab moulds. 369
Bcnier fils, 396

Bernasconi, ornamental plasterer, 141
Bernhardt, S., tragedienne and modeller, 334
Bibliotheque Nationale, plaster work at the, 439
Bickley's patent blackboards, 83
Bielefeld's papier-mache, 393, 397
Birmingham cement, 77
Black finish, 83
Blackboards, 78

„ American, Bickley's, Potter's, S3

Block cornices, setting out, 199
Bloomfield's plasters, 82
Blubs ill plaster, 270

Boiling Hall, decorative plaster work at, 28
Boston Manor House, plaster work at, 17, 32
Bostwick metal lath, 87
Bouchardon's casting wax, 252
Brackets, cornice, 107

fibrous plaster cornices, 356
panelled Ceilings, 126
Scotch, 108
spike and rope, 144
various, 575
Bramshill, plaster work at, 16
Brandered Ceilings, 120
Brass, small tools, making, 545
Brick dust, stucco, and terra-cotta, 8
British and Belgian plaster work, 447, 44S, 449

plaster work, excellence of, 449
Briquettes, cement, 57

gauging for, 58
moulds for, 59
,, ([uantities of materials for, 57, 58

,, with and without sand, 58

Brushed jelly moulds, 327
Bulk of water absorbed by natural stone compared

with artificial stone, 480
Burness's patent non-slippery steps, 516

Index.

583

Bushel boxes, sizes of, 558

Busts a la Belt, 234
„ casting, 326
,, jelly moulds for, 326
,, materials for, 235
„ modelling, 226, 232, 233
„ moulding, 326
„ moulding-piece for, 263, 264
„ Parian cement, 235
„ support for modelling, 233
„ waste moulding, 262, 263

Butt joints for concrete mouldings, 207

/^ALCIMETER for testing slurry, 56

^^ — Calculation strength of concrete, notes for, 503,

5°4
Calipers, 235, 538
Caminus concrete cement, 499
Campo Vaccino, capital in the, 531
Canvas and mortar, use of, 344

cutting, 347

for fibrous plaster, 347

in Egyptian plaster work, 422

tags for fixing, 364

to keep clean, 348
Carbonic acid as a factor in the setting of mortars, 45,

46, 94, 127

Carnock Castle, plaster work at, 18
"Carpere facilius est quam imitare,' 233
Carton-pierre, 395

„ English and French, 395, 396, 397

„ Egyptian, 422

„ manufacture of, 395, 396

„ paper for, 396

Cartouche from Lyons, 440
„ „ Paris, 439

Carved concrete, 508

„ plaster, 442
Cases, fibrous plaster, 337

„ for busts, 326, 327

„ „ jelly moulds, 323, 324

„ ,, straight and circular casts, 339

„ run. 363

„ use of lips in, 326
Cast concrete, 504

„ „ advantages of, 505

,) ,. in situ work, advantages of, 508

„ „ stairs, 486

,. „ „ first use of, 4S6

:■, „ „ use of iron for, 487

„ „ steps, 496

„ enrichment mitres, 308
Casts from the antique for modelling, 226, 236

Casts, paper, without moulds, 394
Casting balcony fronts, 338

,, balusters, 274

,, busts, 326

,, composition, 399

,, fibrous plaster. Se^ Fibrous Plaster

„ gelatine for surgical purposes, 331, 332

,, in concrete. See Concrete

„ „ jelly moulds, 339

,, pediments /// situ, 192, 197, 199, 392

,, plaster, 282

,, Portland cement, 284
wax, 251

,, white cements, 284
Cavetto, to describe the, 524

„ use and position of the, 523
Ceiling at the Alhambra, 428; Astley Hall, 125;
Audley End, 16, 31 ; Berlin, 442 ; Beeslack, 135 ;
Boiling Hall, 28; Boston Manor House, 17, 32;
Bradford, 138; Bramshill, 16, 30; Buckingham
House, 22, 33; Careath, 134; Carnock, 18;
Charlton, 16; Coleshill, 22, 33; Craigievar, 17,
31 ; Delhi, 434; Dublin, 22, 34, 139; the Ducal
Palace, 10, ir; Edinburgh, 137; Florence, 11;
Forfar, 140 ; Glasgow, 140 ; Great Yarmouth, 29 ;
Greenwich Hospital, 34 ; Hanover Chapel, Lon-
don, 23; Holyrood Palace, 19, 32, 137; Kedle-
ston, 34; Liverpool, 137; Locksley House, 29;
London, 18, 20; Losely, 16; Milton House, 21,
^^ ; Moray House, 31; Persia, 426; Pindar's
House, 29; Pompeii, 6; Quidenham Park, 31;
Rome, 5, 437 ; Sevenoaks, 402 ; Sizergh Hall,
15 ; Sly field, 242 ; St Martin's Church, London,
20, 32; St Mildred's Church, London, 19; Tivoli,
London, 447 ; Trinity College, Perthshire, 142 ;
Toddington, 140; Versailles, 21; Vienna, 447;
Winton, 18, 31, 133
Ceilings, ancient, 5, 6, 10, 11, 15; classic, 147;
coffered, 126, 130: coved, 172, 437; decora-
tive, 123, 124, 240; brackets for, 126; brand-
ered, 120; fibrous plaster, 132: figured, 126;
finishing, 131, 132; floating, 127; gauged,
127; geometric, 124; gesso, 402; Gothic, 140;
groined, 142; hard finish for, 131; historical,
123; joist lines on, 122; numerous pieces in, 429;
plain plaster, 90-9S ; panelled, 126; panelling
plain, 346 ; planting panels of, 130 ; renovating,
346; ribbed, 126: Roman, 126: running mould-
ing for, 129; setting out panelled, 12S; setting,
131; sketching old, 124: sound, 120; stucco,
125; white cement, 104-107
Ceilings for circular rooms, 437
Cement wash, 570
Cementation, 515

S84

I)idex.

Cements, 55 ; adamant, 76 ; Bassett's, 77 ; Birm-
ingham, 77; first patent for, 55; Howe's, 75;

hydraulic, 80: Keen's, 75; magnesia, 66;

Martin's, 74; Medina, 74; metallic, 74: Parian,

75 ; Paris, 78 ; Portland, 55 ; Robinson's, 76 ;

Roman, 73; Sheppey, 74; slag, 72; stone, 78;

white, 104
C'endrce de Tournay mortar, 447
Cennini, C, on fibrous plaster (1437), 344
gesso, 403
„ moulding from life, 7

Centre flowers, 302 ; American, 303 ; German, 443 ;

by parcels post, 346 ; cause of less use of, 302,

303 ; fibrous plaster, 350 ; French, 303 ; Indian,

434 ; large diameter of, 302 ; numerous pieces

in, 302 : making, 303 ; modelling of, 304 ;

Persian, 427; plate, 302; prize, 306 ; sanitary,

304 ; use of oval, 303 ; various styles of, 302 ;

ventilating, 304
Centring, circular, 490

„ landing, 489

„ slab floor, 501
striking, 493
Chalk lime, 40
V oil, 323.
Chambers, Sir W., plaster work, 34
Champneys, Basil, on ceiling decoration, 241
Channels for concrete paving, 473, 478
Charters granted to the plasterers by Henry \\\.. 27 ;

547 ; Charles H., 27
Chasing wax moulds, 261
Checking test for Portland cement, 60
Chemical names of plasterers' materials, 559
Chimney-piece plaster, 427, 429
Chinese modelling in situ, 435
„ plaster work, 435
„ ventilation, 435
Chloride of zinc for [laper-mache, 396
Chunam, Indian mortar, 231, 432
Cinque-cento style, 576
Circular casts, 257, 25S

Clark, T. and C, ornamental plasterers, 23, 34
Clay beater, 250

cutter, 250

fences, 252, 255

for modelling, 234

model moulding, 254

modelling, 235

jiiece moulds, 262

squeezing, 262

terra-cotta, 45 i

water for moulding, 252
Clearcole, to make. 571
Coarse stuft", making, 43

Coarse stuff, sugar in, 50
„ „ testing of, 44
Coffered ceilings, 130

,, ,, brackets for, 130

„ „ concrete, 499

in Cairo, 223, 422
cornice „ 423

Coffers, setting out, 112, 113
Collins, A. and \V., ornamental ])lasterers, 23, 34
Colours for architectural models, 248 ; busts, 235 ;
distemper, 571, 572: fresco, 220, 223; Portland
cement, 285, 4S4, 513; rough-cast, 558; scag-
liola, 414; sgraffitto, 213, 215, 216; terra-cotta,
450; various tints, 569
Coloured cements, laying, 484
,, fa(;ades in Austria, 446

,, plaster in Pompeii, 6
„ „ old, 6, 422, 423

setting, 99
,, stucco, 104

statue, 3
Colouring concrete mosaic, 484
,, fresco, 220
gesso, 402
„ plaster, 235, 444, 446
„ Portland cement, 189, 285, 4S4, 513
,, rough stucco, 104

sgraffitto, 213, 215, 216
„ stuccos, 436
Colours on drawings, 559
Columns and arches, setting out, 201

,, constructing plain diminished, 151, 152
„ diminishing, 148

,, diminished fluted, setting out, 148; trammel
for, 149; floating rule for, 148; con-
structing by running, 152 ; machine,
153; casting, 154; collar method, 156;
rim method, 155 ; best formed by hand,

155
diminution of, 532
heights of, 532
hollow, 390

over columns, 201, 203
parts of, 529

setting out flutes for, 151
three-quarter, 203
Combined plaster and jelly moulds, 326, 341
Comparative strength of grey lime and Portland

cement mortars, 46
Compass, Moorish, 429
Composite archivolt mouldings, 533
,, capital, to make a, 269
,, column and entablature, 532
impost mouldings, 533

Index.

585

Composite order, the, 532
Composition, 397

,, American, 566

„ Baldwin's improvements in, 398

„ casting, 399

„ durability of, 397

fixing, 307
„ for centre flowers, 307 ; circular decora-

tions, 398 ; frames, 400
„ hand pressed, 400

„ Indian, 434

„ invention of, 397

„ London, 400

,, materials for, 399

,, modelling, 566

Compositions, 393
Compound moulding piece for jelly, 327

„ pediment, setting out, 198

Concavo-convex mouldings, 335

,, surfaces, 177

Concrete, aggregates for, 460, 461, 462, 463, 464
ancient, 456, 457
,, and iron, 493
„ „ wood, 499

„ aqueducts, 456, 458
,, arches, 458
,, at the Paris Exhibition, 458
,, beams, 499

,, ceilings, cast finished face for, 491
„ chimney-pieces, 512
„ coffins, 515
„ Coignet, 458
,, coloured, 512

„ compared with stone, brick, iS:c., 480
,, compressed, 465

,, compression increases strength of, 464
„ compressive strength influenced by aggre-
gates, 462
., compressive strength of, 504
,, contraction in fine and rough, 472, 476
„ copings, 506
„ crushing strength of, 464, 465
„ domes, 457
„ dressings, 405
» drying, 500
,, durability of, 456
,, evil effect of soft gauged, 465
,, expansion due to cement, 472
„ ,, less in small bodies, 476

„ ,, of fine and rough, 472

fine, 459
„ fire-resisting properties of, 68
,, fixing blocks, 514
„ floors, 497

Concrete floors, ancient, 497

,, and coffered ceilings, 499
,, at Rome, 457
,, Caminus concrete cement, 499
,, centring for, 501
,, chief objects of, 497
„ compressible chases for, 501
„ „ linings for, 503

,, construction of slab, 502
,, first patent for, 497
„ hollow, 503
„ incombustibility of, 501
„ increased strength by coving, 501. 502
„ joist, 498
,, live load for, 503
,, materials for, 502
„ notes for calculating strength of, 503
,, Phcenix, 497
,, resistance to damp, 501
„ safe load for, 502, 504
,, sanitary properties of, 501
„ slab, 501
,, tests of, 504

„ to counteract expjnsion of, 501
,, tubular, 497
fountains, 5 1 1

gains strength by compression, 473
garden edging, 512
gauging, 466
label mouldings, 506
lintels, 514

meaning of the word, 456
mosaic, 482

making, 4S3
,, materials for, 483, 484
„ pavements, 482, 484
,, polishing, 4S4
mouldings in situ, 508.
paving, 468

„ at the Health Exhibition, 475 ; In-
ventions Exhibition, 469: Rugby
Railway Station, 476; York Rail-
way Station, 476
,, best laid in sections, 472

„ wearing, 471
,, claims of plasterers to lay, 460
„ compressive joints for, 476
,, counteracting expansion in. 476
,, cutting tool for, 477
,, dusting, 474
,, Eureka, 469
„ expansion joints, 476
„ falls. War Office rules as to, 478
,, fine aggregate best for, 470

5 86

Index

Concrete paving first introduced by Mr W. B. Wilkin-
son, 459
,, „ frost, preventive for, 48, 466

„ „ for breweries, 479; coach yards, 477;

dairies, 479; food factories, 479 ;
slaughter-houses, 477; stables,
477 ; washing yards, 477
foundation for, 471
grooved, 474
groovers for, 541

grooves for carrying oft" water, 475
grooving, examples of, 475, 478
grouting, 474
hardening, 474, 481, 563
indurating, 481
jointers for, 541
joints in, 476
kerbs for, 473
laid in sitit, 468
laying, 469, 473
levels and falls for, 471
metallic, 468
non-slippery, 474
overlap joints for, 503
plasterers' work, 459
preventing cracks in, 476
])rotecting new, 469, 474
quantities for, 470, 558
quick-setting solutions for, 469
ramming, 473
roughening, 474
sand as an aggregate for, 462
sanitary properties of, 477
screeds and sections for, 472
sections in, 476
slabs, 480
„ making and laying, 481
„ sizes of, 480
,, weights of, 558
stamped, 475
summar)- of, in situ, 4S0
surface joints for, ^76, 477
temperature for, 474
thickness of, 468
trowelling, 473
versus as])halte and other materials,

477
„ Wilkes and Millar's, 469
ramming of, 467
resen'oirs, 45 8
roadways, 484
roofs, 503
sills, 506, 507
sinks, 512

Concrete stairs, 485

„ „ at the Parmiter Schools, 487 ; South

Kensington Subway, 493 ; Tivoli,
London, 495

between walls, 4S9
cast landings, 487

„ steps, 486, 496

,, treads and risers, 496

centring for, 489

closed outer strings for, 497

dimensions of, by figures, 488

dowel holes for. 495

Education Department on, 486

falls for steps, 486

fibrous concrete for, 495

filling in, 491

finishing of, 492

formed in situ, 487

framing for, 488, 489

German tests for, 487

hardening, 493

importance of topping w^hile green,
492

in situ, 487

iron in, 493

jointed nosing moulds for, 488, 492

landings in, 486

London County Council Regulations,
486

making good, 493

non-slippery steps for, 493, 516

nosings and risers, 488

number of steps for, 485

polished soffits for, 495

protect while green, 493

quantities for, 558

ramming, 492

self-supporting, 487

setting out, 487, 488
„ soffits of, 494

size of steps, 486

striking centring of, 493

summary of, 496

tests of steps, 487

waterproof centring for, 490

winders for, 485, 486
string mouldings, 506
strong rooms, 514
tanks, 5 1 1
tenacity of, 457

tensile strength influenced by aggregates, 462
the Builder on, 469
„ Eni^ineer on, 469
trowelling for, 473

Index.

587

Concrete vases, 279, 512

walls, 456, 457, 5 "4
water for, 465, 467
weights of, 557

„ white finish in one operation for, 495
Conventional and naturalistic styles, 227
Copying mouldings, 536
Corinthian archivolt mouldings, 533
capitals, 296, 528, 531
casting, 299

„ „ making, 295, 298

„ ,, modelling, 298

„ „ moulding, 299

„ ,, number of pieces in, 296

,, cornice, constructing, 1 1 1

,, „ setting out, 1 14

„ entablature, setting out, 1 1 1

„ impost mouldings, 533

Cornices, brackets for, 107

„ drawing, 290

,, enrichments, to fix, 112, 113, 117, 118

„ ,, to principle, iii, 238

,, fibrous plaster, 353

„ gauging for, no

,, measurements of, 560

„ running lime plaster, 108, 109, no

,, setting out coffers for, 112

„ ,, modillions for, 112

. ,, white cement, 106
Corona, use and position of the, 524
Coved ceilings, 172
Cracked plaster work, 120
Cradle, 134, 538
Cradling, ancient, 4
Crane's, Walter, gesso work, 402

,, recipe for gesso, 401

Crushing strength of Portland cement concrete having
various aggregates, 465

„ weight of concrete compared with stone,
brick, granite, &c., 480
Cubitt, W., & Co.'s works, 238, 309, 39S, 451, 455
Cupola panels and moulding, 164
Cusped arches, wonderful examples of the plasterer's

craft, 428
Cutting canvas, -347, 355
Cyma, use and position of, 523
Cyma-recta, to describe the, 525
Cyma-reversa, ,, 525

■nvARBY, the, 539

'—^ ,, curious descriptions of, 553

,, floating with a, 95
Dartford Portland Cement Company, 72

Datum-line, meaning of the term, 576
Daubers and plasterers, distinction between, 24
Daubing, 24

,, with mud and wattles, 24
Decorative ornament, dangers of superabundanceof, 239
,, „ first principles of, 239

„ ,, use and abuse of, 240

Degrees of angles, 521
Denston, ornamental plasterer, 20, 33
Dentils, 1 1 2
Depeter, 211
Depretor, 211

Designing decorative plaster work, 239
,, friezes, 241, 243

,, proportion, the principal point in, 240
,, repeated part in, 240
,, unity and appropriateness in, 228
Devil-float, 96
Diaper panelling at the Alhambra, 430

„ „ working, 430

Diapered external plaster work, 431
Dimensions, squaring, 560

,, ,, circular, 562

.. » cubic, 561

„ „ elliptical, 562

„ „ irregular, 561

„ „ superficial, 560

,, ,, triangular, 561

Diminished columns, 148
,, models, 294

mouldings, 159, 164, 294
Distemper, colours for, 572
laying, 572
making, 571
Dodds, R., plasterer and mayor, 550
" Dogga " mortar, 92
Domes, 421

Doric archivolt mouldings, 533

,, capital, to make a, 300

,, impost mouldings, 533

,, order, the, 528

Dormer windows, cement, 209

Doublediminished mouldings byfalsescreedsystem, 160
„ „ „ diminished rule sys-

tem, 161
„ „ „ top-rule system, 162

Drapery, modelling, 226, 227

Drawing a block cornice, 199; centre flower, 306, 307;
compound open pediment, 198; Corin-
thian cornice, 114; Corinthian entabla-
ture, in; cornice, 290 ; cupola with
panels, 164 ; Doric portico, 194 : truss,
290 ; Tuscan column and entablature, 529
„ advantages of, 143, 224, 225, 293, 347

588

Index.

Drawing an order, 529

„ art of, the twin sister of modelling, 224

„ columns and arches, 201

„ diminished columns, 148-151

,, examples for plasterers, 529

„ for Clothic work, 143

„ terra-cotta, 452
„ geometrical, 517

good practice for plasterers, 529
Ionic capitals, 300
„ „ entablature, 300

„ pedestals, 531
„ volute, 301
„ panels, 236, 237
„ panelled ceilings, 133-139
„ quoins, 201
,, raking mouldings, 195
., to scale, importance of, 296, 300, 452
triglyphs, 195
Dubbing out, allowance for, 560
Duplicating piece-moulds, 274
Dutch-rush, uses of, 249, 268, 401

■p FFECTS of salt and frost in mortars, 48
•*— ' Efflorescence in cements, 105, 107

Egyptian plastering, i

Elements of architecture, 522

Elizabethan plaster work, 29, 209

Ellipses, setting out, 518

Elliptical mouldings, 168

Elsley, 'P., metal appliances, 191

Employers and employees, good fellowship between,

5SJ
Employment for plasterers in frosty weather, 369
English plasterers versus French plasterers, 345
Entablature enrichments governed by modillions, 1 1 1

„ position of, 529

„ proportions of, 532

„ setting out an Ionic, 300

Enriched mouldings, ancient rules for modelling, 524

„ plaster for wood staircases, 4S6
Enrichments, cast mitres for, 308
fixing, 112, 117
jointed, 256, 327

„ measurements of, 560

„ mitring of, 117, 119

„ stretching and shrinking, 118

,, to principle, 1 1 1

Eureka paving, 460, 469, 492, 558
Expanded metal lathing, 86
Expansion of Portland cement, 63
Experiments as to wear of Portland cement, 471

„ with cement and sugar for casting, 49

Experiments with fibre antl hair, American, 5 1

,, „ lime and sugar, American, 48 ;

Compton's, 50 ; C.erman, 48 ;
Herzfeld's, 50 ; Indian, 49
External decorative plaster work, 2, 9, 13, 16, 25, 27,

29, 32, 421, 432, 441, 446, 447
External slabs, 373

T7A(;:ADES, Portland cement. See Portland

-'■ Cement

Faija's tests of Portland cement, 57, 61

Fascia, use and position of, 524

Fence, meaning of the word, 576

Fences, metal, 249

„ permanent, 328, 329
,, use of, for model making, 292
,, ,, jelly and wax moulds, 359

„ „ wax moulds, 252, 261

Flamingo, modeller, 229
Fibrous plaster, 343

advantages in designing for, 347

„ saving of time, 346

ancient, 344
and concrete, 333
„ tow, 344, 367
at Cairo, 344 ; Earl's Court, 345 ;
the Naval Exhibition, 345 ; Opera
House, Paris, 344 ; Paris Exhi^bi-
tion, 344 ; South Kensington Exhi-
bition, 344 ; World's Fair, Chicago,
344
balcony fronts, ^.Zl, 2,2,^
Belgian, 447
blocks, 379
brackets, 356
British history of, 343
brushes, 538

brushing firsts and seconds, 349
canvas strips for, 349, 355, 358
case, to make, 337
casting, 348

„ centre flower, 346, 350 ; en-
richments, 360 ; enriched
cornices, 356, 361 ; plain
cornices, 354 ; perforated
work in, 352
compared with lime plaster, T33, 346
cornices, 353, 357

best lengths for, 353
„ drying, 356
fixing, 364
mitre stops for, 353
cutting canvas for, 347

Index.

589

Fibrous plaster, decorative sheets, 366

,, ,, Desachy, introducer of, 343

drying. 337. 338, 352
fireproof, 365
„ ,, for architectural models, 248 ; casing,

beams, and columns, 346 ; centre
flowers, 346 ; enriching plain ceil-
ings, 346 ; panelled ceilings, 346 ;
renovating ceilings, 346; ship deco-
rations, 345 ; stage properties, 344;
stair cases, 495
gauging for, 348
,, hand rules for casting, 361
,, hardening of, 37S

laths for, 348, 350, 351, 353, 354,

375. 377
,, ,, laid diagonally, 376

,, making, 370

„ materials, 347
„ measurements, 365
„ mitre and stop joints in, 353

moulds for, 354, 356
,, muslin plaster casts, 367

nomenclature. 347, 349, 350
,, painted before fixing, 346
„ panelled ceilings, 346

patent for, 343
„ rapid plastering, 367
,, resistance to fire, 366

rims of casts in, 349, 355
„ signboards, 378
„ size water for, 348
,, slabs, advantages of, 368
„ „ adopted by the London School

Board, 368
,, ,, bench mould for, 369

„ ,, combination, 372

„ damp proof, 37S
„ drying, 371
„ external, 373
„ fibro, 347, 371
„ ,, finished-face, 374

fi>;i"g. 37 7
' „ „ ,. moulds for, 375

„ fireproof 372

„ fresco, 378

„ gauging for, 368, 371

.. gesso, 377

„ grooved, 374

,, ., hardening, 378

„ „ Hitchin's inventions for, 367,

372
„ ,, keying surface of 371, 372

„ litharge oil for, 378

Fibrous plaster slabs, machine made, 367
„ Mack's, 374
„ ,, makers' names on, 370

„ making, 370
,, „ ,, in frosty weather, 368

„ ,, materials for, 347

„ metallic, 373
„ ,, moulds for, 369

„ ,, nails, quantities of, 556

„ perforated, 374
„ pugging, 378
„ rack for drying, 37 r, 372
„ ,, reduced fire premiums for use

of, 368
„ reed, 374
,, „ salamander, 372

„ setting, 372
„ „ sgraffitto slabs, 377

„ ,, sizes of, 368

,, ,, superior to match boarding, 368

,, ,, tallow pad for moulds, 370

„ ,, templates, 169

,, ,, unskilled labour bad for, 368

„ ,, versus match boarding, 368

„ weights of, 556
„ „ Wilkes and Millar's, 65

„ wire drag for, 372
undercutting, 353
uses for, 344
Figure modelling. See Modelling
Fillet, use and position of, 523
Fine concrete, 459

Fineness of Portland cement, importance of, 62
Fining Portland cement facades, 187
Finished white face on concrete ceilings, 491
Fireproof construction, compulsory, 333
„ fibrous plaster, 365
partitions, m, 497
Fish skin, use of, 249, 268
Fixing enrichments, 117
„ panels, 130
„ stuff, 130
Flaxman, modeller, 229
Foreign competition in plaster work, 449

„ plaster work, 420
Forsyth on the wretched plasterer from Como, 523
Fortune, C, plasterer and mayor, 551
Framed wax moulds, 359, 363
Francis & Co.'s Portland cement, 72
French architects and the use of plaster work, 430
,, carved plaster, 442
„ mitring, 441
„ plaster work, 43S
„ plasterers and plastering, 440

590

Index.

Fresco, antiiiuity of, 217
art of, 217
„ at Pompuii, 217; Tel-tl-Amarna, 2 1 7

by Maclisc, 217; Michael Angclo, 21S;
Raphael, 218
„ Indian, 220
„ materials for, 21S

panel, 222
„ preparing walls for, 2 1 8
„ secco, 220
Fret enrichments, 309

Frieze at Charlton, 16; Crewe Hall, 16; Hardwick
Hall, 16; Mosque of En Nasireeyeh, 422;
Mosque of Sultan Hassan, 422
„ Persian, 428, 430
,. position of, 530, 532
., swelled, to plaster, 197
„ Turkish, 425
,, with (lower swng, 118
Front wax moulds, to make, 254
Frontispiece, description of, 250
Frost repellents for plaster and cement works, 48
Funnels for jelly moulds, to make, 324

to use, 326, 337, 342
Furred moulds, wax, 284

/^ATCH plaster, 425
^^ Clauge, the, 540

boards, 540
pots, 249
rules, 539
Gauged work, 1 2 1

Gauging, definition of the word, 577
Gelatine, anti-mould acid for, 321

„ British made, better than foreign, 318

„ brushed gelatine moulds, 327

„ casts, for surgical purposes, 331

,, combined jelly and plaster moulds, 341

„ compound moulding piece, 327

„ covering capacity, 556

„ dissolving, 320

„ evils of painting, 330

„ flexible, 319

glycerine for, 319
„ indurating solutions for, 319
„ insoluble, 318
„ interchangeable moulds, 340
invention of, 317
its uses for moulding, 317
manufacture of, 318
moulding, 317

in, 325
„ ,, balcony fronts, 336

„ „ busts, 326

Gelatine moulding casts, 329

„ .. clay models, 329

trusses, 326
,, „ white models, 329

moulds, cases for, 323

chalk oil for, 323
„ „ compared with wax moulds, 318

„ „ for casting Portland cement, 285,319,

33'
„ „ gum oil for, 322

„ „ interchangeable, 340

oiling, 322
„ open, 329
„ ,, petroleum oil for, 223

„ pouring on, 325
„ „ preserving. 318

„ ,, seams and blubs in, 322

„ „ seasoning originals for, 321

oil, 321
„ „ „ paraffin wax, 322

„ „ „ shellac, 321

„ straight, 330
„ „ „ and circular, 339

„ „ sugar wash for, 319

„ ,, use of channels for, 324

„ vents for, 323, 337
„ „ varnishes for, 330, 331

„ „ without cases, 329

pots, 320
„ soft casts, 331

spotty casts, 331
„ stiffening rules for, 336, 342
„ tests for, 318
Gentlemen plasterers, 32
Geometry, 517

German experiments as to effect of frost on mortars, 48
,, Government interest in plaster work, 442, 443

mortar, 443, 444, 445
,, oil for plaster moulds, 279
„ plaster slabs, 443
work, 442
„ Portland cement, 62
„ prizes for weather-proof plaster, 443
„ tests for concrete stairs, 487
„ white cement, 567
Gesso, 400

„ antiquity of, 400

,, at Coire, 406 ; National Gallery, 400 ; \\'est-

minster Abbey, 401
„ ceiling, 403
,, Cennino Cennini on, 403
„ colour, 402

,, Crane's, Walter, ceiling in, 402
„ ,, ,, recipe for, 401

Index.

591

Gesso, duro, 402

„ grosso, 402, 405
„ materials for, 400, 401, 402
,, method of working, 401
,, modelling in, 400, 402
,, polished, 405, 406
„ Robinson's, G. T., method of, 401
„ slabs, 377
„ sottile, 402, 405
Gilchrist's, A., stamps and rollers, 481, 541
Girardon's wax for casting, 251
Glass cubes and plaster decoration, 434
„ ground for busts, 235
„ ,, concrete, 514

„ ,, plaster work, 434

„ moulds, 374, 409, 416
„ plate for modelling, 247
Glossary, 574
Glue moulds, 330, 403
Glycerine a frost repellent in mortars, 48

,, ,, ,, for concrete paving, 48

,, composition, 568
,, use of, for jelly moulds, 319
Gothic arches, to describe, 520

ceiling at Toddington, 140

setting out, 143
groined ceiling at Trinity College, 142

„ ceilings, forming screeds with running

moulds, 143
„ ,, intersection boards for, 143,

145, 146
„ ,, jack template for, 143, 146

„ ,, mitring ribs, 146

pin moulds for, 143, 145
„ „ running ribs without screeds,

143
„ ,, spike and rope brackets for,

144
,, „ templates for, 143

modellers, 141, 142
mouldings, 523

„ casting, 286
„ materials for, 147

plasterers, 141, 142

plastering, 141, 142, 143, 144, 145, 146
style, Ruskin on, 140

,, Walpole's writings on, 140
wheel window, to describe, 521
Goujon, Jean, modeller and architect, 523
Granite plaster, 81
Granitic concrete quantities, 558
„ finish, 418
,, plaster quantities, 556
„ plastering, 418

Grant on Portland cement, 63

Grecian capital, 529

Doric column and entablature, 527
Ionic column and entablature, 527
mouldings, to describe, 525
orders, the, 528
stucco, method of using, 4
temples, plaster pavement in, 2

Greek honeysuckle ornaments, 452

Groined ceilings, 142

Grooved floating rule, 539

Grounds, meaning of, 577

Guggenheim on stucco, 103. 436

(iuilloche, mitres of, 309

Gum oil, 322

Gutta-percha moulds, 475

HAIR, SI
,, dry and wet, 51
„ ox, horse, and goats', 5 i
„ quantities, 555
,, substitutes, 51
„ weights, 555
Haired putty setting, 5 1
Hand work compared with cast work, 422
„ „ decorative plaster, 230
„ „ examples of, 230, 231, 232
Hanging running moulds, 314
Hanwell, C., modeller, 343
Harling, 210
Hawk-boys, 550

,, ancient, 10

server, 546
Heat, relative conductivity of various materials, 558
Helical metal lathing, 88
Hinged running moulds, 294
Hobb's, P., concrete, 475

Hobmans, A. C, pioneer of concrete mosaic, 483
Hollow casts, 284, 390
Hoogood, H., ornamental plasterer, 19
Homan and Rodgers' concrete, 479, 497
Howe's cement, 75

Hugo, Victor, on plaster of Paris, 438
Hydrate of lime, 42
Hydraulic cements, 80
„ plaster lime, 81

T MPERIAL Stone Company's, The, concrete slabs,
■»■ 476. 481

Impost mouldings, 533
Impressed plaster work, 223, 230

old, 25
Indian centre pieces, 434

' 1

592

Index.

Indian chunam, 432
„ fresco, 220
„ indurating plaster, 434
marble plaster, 320
modelling in situ, 435
jjlaster work, 432
„ plastering, 432, 435
Indiarubber moulds, 332
In situ, meaning of the term, 577
Intersection of square and splayed angle mouldings,

3>S
„ straight and circular mouldings, 172,

174
Ionic archivolt mouldings, 533
„ capital, to make, 300
„ impost mouldings, 533
„ order, Grecian, 528
„ Roman, 539
„ pedestal, to set out, 531
„ volute, to draw, 30:
Iron plaster, 83

Irregular figures, reducing or enlarging, 289
Italian lime, secret of making, 435, 436
„ plaster casters, 550

work, 435
„ plasterers, past and present, 435
,, Renaissance, 9, 1 1
„ stucco, 437

JACK template for running C.othic ribs, 143
Jackson, G., c\: Sons' plaster works, 343, 345, 395,

397. 402. 448
Jacobean plaster work, 30
Jay, G. M., inventor of wedge mould, 505
Jerry-builder and plaster work, 302, 550

,, origin of the term, 577

Jewish plaster work, 2
"Jhilmil," metal lathing, 86
Joggles for baluster piece moulds, 272

„ „ cases, 324, 326, 327

„ ,, plaster piece moulds, 270

„ „ wax moulds, 259, 263

„ raised, 273

„ run, 388

„ wood, 261
Joggler, the, 266
Joints in enrichments, 327
Jointing casts for jelly moulding piece, 327
Joint lines on ceilings, 122
Jones, Owen, first patron of fibrous plaster, 343
Jones, T., fibrous slabs, 370
Jubilee coffin, 515
Jupiter Stator, capital at the temple of, 531

KANKAR lime, 432
Keen's cement, 75

casting, 284
„ „ working, 104, 107

Kettering iron furnaces, slag from, 464
Keying, 96, 185, 467

„ evils of non-, 5 1
Keystone, making, 294

„ in terra-cotta, 452
Kufic frieze, 421, 422
„ inscriptions, 42S

LABOURERS' tools, 546
,, wages, ancient, 25

,, weight carried by, 542

Lascelles' concrete, 458, 514
Lath, plaster, float, and set, 90

weight of, 558
Lathing, 85

„ ancient, 4
„ Bostwick metal, 87
,, expanded metal, 86
,, Jhilmil metal, 86
,, metal, 86
,, ,, sheet, 88

„ plaster and wire, 88
,, reed, 88
„ slate, 88
,, Vitruvius on, 4
,, wire, 88
Laths, covering capacity, 555
,, fibrous plaster, 34S
„ hand and machine made, 85
„ nails, quantities, 555

„ weights, 555
„ quantities, 85, 555
Latto's canvas, 347
Lead moulds, 230
Levelling rule, 159, 539
Lime, 38

analysis of Scotch, 41

and sugar, as used in Madras, 49

Arden, 39

circulating quantities, 556

chalk, 40

coarse stuff, covering quantities, 556

„ testing, 90
effects of carbolic acid in, 41
Gillmore on, 64
grinding, 43

hydrate of, meaning of, 42
hydraulic, 39

importance of fine grinding, 40
in the eye, 569

{

Index

593

Lime, Irish, 41
kilns, 41
Lias, 39

M'Ara's process of grinding, 39
measures, 556
plastering quantities, 556
pure, rendered hydraulic, 44
putty, 50

,, for mitring, 50
Reid on, 64
rich, 40
Scotch, 40

slaked for three months before using, 42
slaking, 42

„ amount of water required for, 42
,, by absorption, 42
,, „ immersion, 42
,, ,, sprinkling with water, 42
,, quantities, 556
Theil, 64
Vicat on, 39
Vitruvius on, 4
water, 51
weights, 566
Limestone, chemical composition, 38

,, where obtained, 38

Lime wash, 571

Limewhite, covering capacity of, 556
Litharge oil, 378

Lombardi, A., stucco modeller, 9
London County Council, law as to staircases, 486
Looking-glass, use of, for modelling bust of self, 326
Lundgren on Indian plastering, 435
Lysistratus, first moulder of living faces, 264

1\ /[■ 'ARA'S process of air-slaking Portland cement,

M'Donald, J., first worker in fibrous plaster, 343
Maderna, C, modeller and architect, 523
Magnesia cement, 66
,, in mortars, 47
,, „ Portland cement, 65
Marble casts, 566

„ mortar, loi

„ plaster as used in Jeypore, 220
Marezzo marble, 416

„ „ making, 416

Marmorite, 410
Martin's cement, 74

,, „ working of, 104, 107

Martmoratum, 102
Mastic, S3

,, covering capacity, 556

„ Greek, 568

Mastic, Hamelein's, 54
„ London, 54
„ manipulation, 54
„ Scotch, 53
Materials, 35, 55

„ adulterated, evil effects of, 549
„ for modelled plaster, 245
„ knowledge of, needful, 548
Matrix, meaning of the word, 460, 577
Measuring plaster work, 560
Mediaeval ,, ,, 25

Medina cement, 74
Metal fences, use of, 249

„ moulds, 274, 393, 395
Metopes, position and use of, 529

,, setting out, 195
Michael Angelo, sculptor, 523

„ on stucco modelling, 9

,, and use of pouncing process, 237

„ work at St Peter's, Rome, 523

Middleton, Professor, on concrete, 457
Mihrab, plaster work in a, 424
Millar's, R., collection of tools, 546
Minio, a female stucco worker, 15
Minocci, P., stucco worker in Florence, 11
Mitre and stop joints, 353
Mitring, 115

,, enrichments, 117, 308
„ „ good and bad work, 238

„ „ hand worked, 239

„ „ modelled, 239

„ „ setting out in shop, 239

,, „ stretchers and shrinkers, 23S

„ guilloches, 309
,, mould, 116
„ ornamental angles, 177
,, Portland cement mouldings, 187
,, rib intersections, 146
tools, 542
Model making, architectural, 247
,, balusters, 271
,, Composite capital, 299
„ Corinthian „ 295
,, enrichments, 255, 308
„ example for plasterers, 529
,, good practice for plasterers, 530, 531
„ Ionic capital, 300
„ keystone, 294
,, terra-cotta, 452
,, truss, 290
„ use of small scale, 235
Modelled concrete, example of, 511

„ plaster, 240, 241, 242, 243, 244
„ „ first use of, in France, 438

594

Index.

Modelled plaster, materials for. 245

stucco, 3, 5, 8, 9, 10, II, 12
Modellers' blouse, a garb of honour, 232

diplomatic correspondence, relating to, 13
„ (larland, T., the father of modern, 233

Modelling, 224

(/ la Belt, 234
„ antiquity of, 224

„ a knowledge of mythology useful for, 226

„ Aitchison, Professor, on, 230

„ Art schools and, 225, 236

„ artistic effects of, spoilt by smoothing, 244

„ busts, 226, 235

„ casts from the antique, useful for, 226, 236

„ „ nature, uses of, 236

„ centre flowers, 304

clay for, 234
„ cobbling to save expense of, 228

„ combined, and stamp work, 230

„ comparative cost of cast and hand work,

228, 230
„ composition, 566

„ Corinthian capital, 298

„ designing, 239, 240, 241

„ drawing essential for, 224, 235

„ educates the hand and eye, 235

„ enrichments, 238

„ expresses ideas better than drawing, 235

„ false economy on weak foundations, 245

„ flat and high relief, 240, 243

figure, 225
„ „ a knowledge of allegorical subjects

essential for, 226
„ „ advantage of, 226

„ ,, casts from the antique for, 225

„ „ copying from nature for, 225

„ „ half figures, 237

„ „ in Austrian fa^'ades, 446

„ ,, „ cement, 246

,, ,, life models for original subjects, 226

„ ., proportioiisof the human figure, 225

„ ,, terracotta, 452

„ ,, use of anatomy for, 225

„ for plasterers, 530

„ frieze and ceiling decoration, 241

„ Greek and Roman foliage, 297

„ hand work, 230

,, imitation in design, an error, 227

„ importance of drawing for, 224

„ in cement as easy as in clay, 229

„ .. fine concrete, 510

„ ., plaster, 4, 235

„ „ stucco, See Stucco

„ tow, 247

Modelling in wax, 246

„ in situ, 229, 244

„ „ advantages of, 178, 201

„ „ an impetus to the art of, 229

„ „ art and uses of, 229

„ ,, economical and effective, 178,201,

209
plaster, 425
„ judging the effects of, 228

„ looking-glass, use of, for, 233, 236

„ medallions in wax, 246

method of, 235

naturalistic and conventional styles, 227
„ panels for copying, 236

„ pate plastique, 235

„ pilaster panel for copying, 237

„ plaster as a ground for, 237

„ „ and tow for scenic work, 344

„ plastilina for, 234

„ portraiture, 226

„ prizes for, 548

„ proportion important in design, 240, 241

„ repetition in design, 240

„ retention of models detrimental to the art

of, 228
„ shop, 232, 250

„ „ and building work and, 229

„ study of anatomy, useful for figure, 225

„ supposed origin of, 577

„ textures in clay, 227, 236, 243

,, the acanthus leaf, 298

„ ,, best method of expressing form, 224

„ ,, modeller's art, 228

„ ,, principles of, 224

,, „ study of the human figure imperative

for, 224, 237
,, „ twin sister of drawing, 224

tools, 233, 234
„ truss enrichments, 293

„ unity and appropriateness in design for,

228
„ use of copying for, 235, 237

„ versus cdiSt. \\oxV, 178

„ wax, 247

„ Webb, Stephen, on modelling for plaster

work, 243
,, window heads, 209

Modillions, 199

casting, T13
„ drawing of, 290

„ fixing, 113, 190

„ govern the enrichments, in

„ right, left, and centre, 196, 197

„ setting out, 112

Index.

595

Modillions, to principle in facades, 203
Module, parts of a, 529
Moulds for composition, 398

concrete copings, 507

,, ,, in situ, 408

,, cornices in situ, 408
,, nosing of steps, 488
sills, 507
step, 488
,, string mouldings, 506, 508
finished face slabs, 375
turning columns, 412
„ interchangeable, 340
„ reverse, 380
rims of, 348
Moulding box, use of, 255
,, bust, 326
„ casts, 329
„ centre flowers, 306
„ clay models, 329
,, Corinthian capital, 299
,, enrichments for fibrous plaster, 356
„ for terra-cotta, 453
„ from life, 264
„ ,, ancient method of, 2, 7

„ hammer, 266
„ in gelatine, 325

„ paper, 394
„ „ plaster, 265

„ „ sulphur, 398

„ wax, 252
„ models without a ground, 341
„ old mouldings, 536
„ plaques, 261

„ plaster piece. See Piece Moulding
„ white models, 329
Moulding piece for balconies, 334, 336
„ dentils, 359
„ ,, ,, egg enrichments, 256

„ „ „ front and back. 260

„ ,, ,, fibrous plaster enrichments, 359,

362, 363, 364
„ ,, ,, perforated coves, 260

„ „ „ soffit, 254

„ ^ „ „ sunk panels, 363
„ ,, compound, 327

.. meaning of the term, 578
„ „ seasoning, 321

„ „ stock, 329

„ „ without joggles, 362

Mouldings, the regular, 523
to copy, 536
,, u.se of drip members, 509

Mortar, 43

Mortar and beer, eggs, milk, sugar, &:c., 102, 432 ;
brick dust, 44; bullocks' blood, 102 ; fibre,
102; marble dust, loi, 103; pitch, 102;
rice, &c., 103 ; rye dough, 103 ; sugar, 48,
40, 50; unctuous earth, 103; urine, 103;
wax, 102
Chinese, 435
" Dogga," 92

effects of salt and frost in, 48
German, 443, 444, 445
hardening of, 45, 94, 127
importance of quality of lime in, 45
Indian, 432
magnesia, 47
mills, 43
old, 45, 102

proportions of materials for, 43
proverbs on old, 45
quantities from various limes, 557
Roman, 49
salt water in, 48
Westmacott's, 64
Moorish plaster work, 428
Mosaic, 482

,, concrete, 482
,, ,, laid in situ, 483

polishing, 484
Muffled moulds, 316

„ „ for panel mouldings, 130

Mural Decorations Company's patent plaster, 406
Muslin plaster casts, 367
Mutules, position and use of, 529
,, setting out, 196

TVJAILFLOAT, 96

^ ^ Name panels in decoration, 340

Name plates for slab moulds, 481

Naturalistic and conventional styles, 227

Nelson's gelatine, 331

Neeves', P. le, recipe for stucco, 14

Nibby, Antonio, on lime concrete, 456

Niches, 178

„ crowns of, 180

„ fibrous plaster, 180

„ of Fame, the plasterers', 34

„ run, 178

,, to set and construct an Ionic, 197
Nonsuch, plaster work at, 13, 26, 27

,, the plasterers' pride and pleasure, 27

/^CTAGON, to form an, 518

^^ Ogee, use and position of the, 523, 524

Oil seasoning originals, 321

Oiling jelly mould.s, 322

596

Index.

Oiling plaster moulds, 279
.. wax moulds, 280
wood moulds, 491
Old lime putty for fresco plaster, 218
Opus alharium stucco, 10 1
Orders of architecture, 527
Ornamental pierced work, 207

„ plaster, its use and treatment, 239

„ „ sanitary, durable, and fire resist-

ing, 239
stucco work, produced by a patent process,
223
Ostell, Van, plaster work at the Louvre, 438
Oval, to form an, from circles, 51S
Ovolo, to describe the, 524

„ use and position of the, 523

mouldings, 129

pAINTS, 573
■*■ Pant
Panelled beams. 166
ceilings, 126

„ and concrete floors, 499
,, Gothic, 140
„ in the classic style of, 147
„ lathing, floating, setting out, and
finishing in limes and cements,
126, 128, 133, 134, 135, 136
„ „ pendentive, 428

„ „ planted, 130

„ ,, Portland cement for, 132

working plans of, 133, 134. 135, 138
„ coves, 158, 172-177
„ cupolas, 164
,, fascia, 177
„ sofliits, 165, 362
Paper as a substitute for hair, 435

„ casts without moulds, 394
Papier-mach^ manufacture, 393
„ moulds for, 394

„ stage properties, 393

Papworth, J., ornamental plasterer, 23, 34
Paraffin, uses of, 319, 322, 330
Pargetting, 28

Pargettors, commonly called " plaisterers," 14
Parging and plastering, 15, 18
Parian cement, 75

„ „ covering capacity, 555

,, .. finish and Portland cement, 105

finishing in, 106
„ ,. floating ceilings, 105

„ „ for repairs, 1 2 1

gauging, 105
i> ,. running cornices in, 106

Parian cement solution, 1 2 1
trowelling, 107
weights, 555
„ work, 104, 107
Paris cement, 78
Partitions, concrete, for balcony fronts, 333

„ wattles and plaster, 420
Pasley, General, on hydraulic cements, 80
Pate coulante, 397
„ plastique, 235
Paterse, casting and fixing, 113

designs of, 437
Pavements, ancient plaster, 2, 4
Pedestals for balustrades, 203, 535
,, formed in situ, 206
,, making models of, 198
,, Ionic column, to set out, 531
Pediments, 191

,, compound open, 198

,, inverted circular, 197

pitch of, 192, 195
,, to cast in situ, 191, 197

,, ,, construct in cement, 191, 197

Pendant patera, to make, 362

„ use of, 174
Pendentive arches, 428
„ ceilings, 428

working, 428-430
Pergolesi's design for wall decoration, 22
Persian method of working domed ceilings, 427
,, plaster work, 424

,, ,, at the Paris Exhibition, 427

„ plasterers, 426
Peru, ancient concrete and plaster in, 457
Petrie's, Dr, discoveries of ancient plaster work, i, 344
Petrura plaster, 82
Piece moulding a baluster, 272

a bedding piece in, 340

a hand, 264

a modillion, 268

a vase, 274

as in Venice, 9

cases for, 267, 271, 274

clay models, 267

closing pieces for, 267, 277

combined with jellv, 341

duplicating, 274

fences for, 269

figures for, 270, 273, 275, 278

for carton-pierre, 267

from life, 264

,, ancient method, 7
in plaster, 265
joints in, 268

Index.

S97

Piece moulding joints, best places for, 277
„ „ „ cutting, 269

flush, 276, 27S
for jelly, 326, 341
„ „ „ sunk, 267, 276

,, „ laying plaster for, 271

,, ,, links for, 278

,, „ Lysistratus supposed inventor of, 264

,, „ "on the round," 272, 274

,, „ plaster for, 266

,, ,, rim pieces for, 275

„ ,, seasoning models for, 266

,, ,, shoulder piece for, 270, 278

„ ,, size of pieces in, 267

„ ,, use of dots in, 271

„ ,, ,, thickness rules, 271

„ „ wedge pieces in, 278

,, ,, wire eyes for, 268, 277

,, ,, works in, 265

in clay, 262
„ ,, „ plaster and wax, 256

,, wax, 261
,, ,, Verochin, A., pioneer of, 9

„ moulds, running, 380-383
Pierino del Vagu, hawk boy and modeller, 10
Pilasters, diminished, 158

proportions of, 533
window, 208
Plaster, adhesive strength of, 38
American, 84
ancient use of, 7
and tow, uses of, 367
Asbestic, 78
baked, 37

Benvenuto Cellini's choice of, 38
boiled, 36
Bristol, 38

British and American terms for, 35
Cafferata's, 38

casts, cause of blubs in, 283
,, hardening, 563
„ hollow, 284
,, impervious, 56S
,, of natural objects, 567
„ polishing, 564
,, washable, 565

waterproof, 56S
,, whitened by sunshine, 283
casting, 282

,, antiquity of, 282
,, in wax moulds, 2S3
chimney-piece, 429
compressive strength of, 38
designed by Dame Nature, 265

Plaster, difference between stucco and, 102
Egyptian, i

etymology of the word, 35
fire resistance of, 443
first use of, in England, 14
floors, 498

foreign names for, 578
French, 38
gauging, 281
(Ireek, 35
hand-made, 35
hideous use of, 425
Hotel de Platres, 38
Howe's pink, 38
" killed stuff," 281
linen and glue, old use of, 403
manufacture, 36
moulds, water-seasoned, 285
moulding from life, 264
old price of, 25
of Paris, 35

piece moulding. See Piece Moulding
quantity for gauging, 281
quick and slow setting, 37

,, gauged versus slow gauged, 281
slabs at Tel-el-Amarna, 283
soft gauged versus stiff gauged, 28 1
statuary marble, 566
strong, 284
testing, 37

to set quick, 565 ; to set slow, 565
use for old, 282
use of, for moulding, 265

,, in Paris, 440

„ measures for gauging, 281
waste moulding, 262
weights of, 555
Plasterers, Acts relating to, 24, 27, 30

ancient, 1-32

and architects, 523
,, civic honours, 550
,, daubers, distinction between, 24
„ jerry workers, 27
„ M.P.'s, 551
,, piecework, 549
,, whitewashing, 550

appliances, 537, 555

apprentices, 28, 549

arms, 547

benefits of master, 549

census of, 551

certificates of competency, 105, 551

charter, 547

Company, the, 547

598

Index.

Plasterers, craft, the, 548

definition of, 578
„ El Dorado, 550
„ emblem, 250
„ feast days, 25
„ " field rangers " and, 550
„ fined for plastering, 548
„ fines for bad materials, 28
„ ,, „ workmanship, 28

Hall, 548
hawk boys, 550
London, 548, 550
master, 549
„ „ agreement, fourteenth century, 25

,, „ craftsmen, 27

memoranda, 555
motto, 250, 548
mud (1189), 24
oval, 1 70
„ pioneers of concrete paving, 459

plant, 537, 546 ; banker, 538 ; brushes, 538;
brooms, 5 38 ; calipers and compasses, 538 ;
cradle, 538 ; drags, 539 ; files and rasps,
53S ; floats and rules, 538 ; gauges, 540;
gauge-boards and stands, 540 ; groovers
and rollers, 540 ; hammers, 540 ; hods,
541; iron floats, 546, 549; larries and
rakes, 542, 546 ; pails, 543, 546 ; planes,
544 ; punching sieve, 545 ; putty box,
546; riddle rest, 545 ; saws, 544 ; scaffolds,
544; scaffold trestle, 546; scaffold slip;
head, 546 ; scratches, 544 ; screens, 544 ;
sieves and riddles, 545 ; slack box, 546 ;
squares, 545 ; radius rods, 543; templates,
545 : tubs, 546
pri7.es for, 548, 552
,, provincial master, 549
quantities, 555
riots, 548
„ Shakespeare on, 28
„ shop, 249
\, sweating and, 550
„ technical training for, 551
techniijue of plastering, 105
tools, 537 ; brushes, 537 ; brooms, 537 ;
calipers, 537 ; chalk-line, 537 ; com-
passes, 537; drags, 537; gouges and
chisels, 540 ; hammers, 541 ; hand-floats,
540; hawk, 541; home-made small
tools, 547 ; joint rules, 542 ; knives, 542;
large collection of, 546 ; level, 542 :
mitring tools, 542 ; pincers, 542 ; scratch
tools, 543 ; small tools, 544 ; squares, 545 ;
tool box, 545; trowels, 545 ; to clean, 546

Plasterers versus bricklayers, 28, 548
„ carvers, 347
„ „ masons, 28

„ „ non-plasterers, 459

„ „ painters, 16, 30, 548

,, wages in the thirteenth, fourteenth, and

sixteenth centuries, 24-27
„ high, of, 550
„ with two trades, 549
Plastering, art of, 89
„ lime, 89
„ „ first-coating, rendering, scratching,

keying, 90, 91
,, „ floating, plumbing walls, screeding,

flanking, common floating, floating

with a darby, keying, devilling, and

scouring coarse stuff, 92-96
„ „ setting, laying, scouring, trowelling,

and brushing, setting stuff, coloured.

common, skimming, and gauged

setting, 97-100
„ „ angles, 100

„ ,, cornices, running, 108

„ ,, fixing enrichments, 117

„ „ gauged putty set, 100

„ mitring, 115
,, „ enrichments, 117

„ I'ugging' 119

„ quantities, 556
,, ,, Shakespeare on, 28

,, „ skirtings, 100

,, ,, stucco, 101-104

„ „ two-coat and three-coat work, 90, 10 1

Plaster-work, ancient, i, 2, 3, 4, 5, 6, 24, 282, 420, 457

British and French systems, 441

colour indications for, 559

combined with stone and brick work, 431

cracked work, 1 20

damp walls, ancient method of, 4

dimension book abbreviations, 560

evil eftect of scamped, 549
,, ,, unskilled labour, 549-551

foreign competition, 447, 449
„ names for, 578

historical, Anglo-Saxon, 14; antiquity of,

1, 24; Egyptian, i, 2; Elizabethan,
15, 29; Georgian period, 21; (Ireek,

2, 4; Irish, 22, 34; Italian Renais-
sance, 7, 9, II ; Jacobean, 17 ; Jewish,
2 ; niedireval, 25 ; Norman, 14 ; primi-
tive, 24; Roman, 5-10; Scottish, 17,
19, 21, 31; Stuart dynasty, 19; six-
teenth, seventeenth, and eighteenth
centuries, 27, 31, 32, 33

Index.

599

Plaster-work, insanitary, 95

„ machine for, 548

„ measuring, 560

„ meaning of the term, 578

,, mud, 102

„ natural covering of walls and ceilings, 240

„ repairing old, i 20

sparkling effects, 432-434
„ universal lining for walls, 89

,, unremunerative, 55 I

,, value of labour and materials, Table, 559

„ with glittering effects, 434

Plastic literature, 551

,, materials, weights of. Table, 558
,, meaning of the word, 578
„ terms, 89
Plastalina, 234
Plastography, 578
Pliny on mortar, 43

,, moulding from life, 264
,, old lime, 42, 50
,, slaking lime, 5
,, stucco, 10 1
Polisher for concrete mosaic, 484
Polishing concrete mosaic, 484
,, marble plaster, 22 t

plaster work, 432, 433
„ scagliola, 115
Porosity of materials, 557
Portico, setting out a, 194
Portland and Sheppey cement fa<;ades, 182
cement, 55
,, ,, acid-proof, 568

„ ,, adhesion of, 63, 65

„ ,, adulteration of, 57, 71

„ ,, aeration of, 65

,, ,, affinity for moisture, 465

aggregates for, 281
air slaking, 63
,, ,, analysis of. Table, 57

J, ,, and lime, comparative strengths of.

Table of, 46
,, ,, ,, sand, comparative strength of.

Table, 557
covering capacity of, 557
„ „ „ ,. wear of, 47 1

,. „ „ sea-water, 465

„ „ „ sugar, 48

„ „ Austrian, 62

„ ,, Bamber's tests for fineness of, 73

„ „ briquettes, 59

„ ,. casting, 284

„ „ „ dry process, 286

„ „ „ hydraulic power for, 289

Portland cement casting, sugar for jelly moulds, 49
„ ,, ,, water- seasoned moulds for,

285
„ casts, cause of fire cracks in, 285
„ ,, porous moulds, cause of sur-

face cracks in, 490
,, ,, pressed work, 286

,, cold atmosphere retards setting, 474
,, chemistry of setting, 68
„ chief qualities of, 57
,, coarse residue valueless, 62
,, colour, solution for, 513
,, coloured, 285
„ compressive strength of, 6 1
,, contraction of, 63
„ effects of age on, 66
„ „ salt in, 48

soft gauging, 461
,, example of tenacity of, 461
,, expansion of, 63
,, facades, 181
„ ,, and brick work, 182

„ ,, balustrades for, 204

„ ,, best for resisting damp, 183

,, ,, block cornices and quoins

for, 199, 201
, ,, columns and arches in, 201

„ „ coloured, 189

,, ,, combined with stone and

brick work, 182
,, „ compared with stone and

other materials, 1S2, 183
,, ,, compound open pediment

for, 199
„ „ depeter for, 211

„ „ desirability of, 183

,, Doric porticos for, 194
., „ fixing modillions for, 199

„ points in, 190
,, „ for casing old stone, 183

,, „ future use of, 184

„ „ gateways for, 201

gi^uging for, 184
,, „ importance of keying and

wetting, 184
,, „ Ionic niches for, 196

„ „ materials for, 184

,. ,, methods of working, 184

permanent screed process,
184; plaster screed pro
cess, 189; fining, 187
running mouldings, 185
„ „ modelling /«J/'/« economical

for, 178, 201, 209

■ 79

6oo

Index.

Portland cement f:i( adrs. old examples of, 181-1S3
„ „ pedestals for, 198

„ „ [)ediments for, 191-197

„ „ „ preserving and colouring, 190

rapidly rci)aired, 183, 205
„ „ ,, rustication for, 201

„ „ „ sand for fining, 188

„ „ ., scaling, cause of, 183

„ „ „ sgraffitto work for, 1 89

„ „ „ superior to soft stone, 183

,„ „ „ three I [uartcr column for, 204

„ „ „ trowelled surfaces for, 189

„ ,, „ vermiculated work for, 200

„ „ ,, windows for, 207, 208, 209

„ „ fine, grinding of, 62, 70

„ ,, „ relative cost of, 70

„ ,, „ strongest and cheapest, 73

„ „ fineness, importance of, 60, 70

„ ., fire-resisting properties of, 67

„ „ German, 62

„ ,, hardening of, 69, 7 1

„ ,, increase of strength. Table of, 67

„ ,, influence of light on, 67

,, „ initial set of, 69, 467

„ „ lime mortar, 444, 446

M putty, 514
,, „ magnesia in, 65

„ „ manufacture of, 55

„ „ relative fineness and cost of, 70

„ ,, setting, time of, 68

„ ,, „ accelerating, 66, 288

„ „ sieving, 58

,. „ specific gravity of, 57

„ „ specifications for, 69

„ „ tenacity of, 461

„ „ testing of, 59

1. ,> „ by boiling, 60 ; checking

test, 60 ; colour, 57, 59 ;
fineness of, 62, 71;
needle, 60; sand, 61;
soundness, 62 ; tensile
strength, 60, 61 ; trans-
verse strength of, 62 ;
weight, 56, 57, 59
,, without a machine, 62
to set quick, 66
trade in, 72
weights, S57
white, 484
work value of, 559
Potter, T., on Portland cement work, 289, 508
Pouncing for reproducing designs, 222, 237, 293
, -Michael Angelo's use of, 237
„ Raphael's use of, 237

Practical geometry, 5 i 7
Preserving plastered fa^;ades, 190
Pressed cement work, 286

„ screeds, 158
Prior, E. S., on modelled plaster, 240
Primary cause of decay in stucco work, 45
Primaticcio, modeller, 12, loi
Primitive mode of plastering, 24
Prize centre flower, 306

„ cornice, 312
Prizes given by the Plasterers' Company, 548
Profile, 524

Proscenium panel, to make a fibrous plaster, 341
Pugging, 119, 378, 497
Puzzolana, 44

QUANTITIES of materials (in various gauges)
required to make one cubic yard of gauged Port
land cement and sand. Table, 557
Quantity of mortar produced from one imperial bushel

of various limes and cements. Table, 557
Quarter round, to describe the, 524
Quick-setting solutions for concrete, 469
Quoins, setting out, 199, 201

"D ADIUS of segment found by figures, 521

■*^^ Radius pin, use of, 134

Radius rod, the, 543

„ mould, uses of, 175

„ uses of, 1 76

Raking cyma-recta, to describe, 192
„ modillions, setting out, 194
,, mouldings, setting out, 192, 193
„ returned cornice, to describe, 193

Raphael and stucco work, 9

Rapid plastering, 367

Recipes, 563

Rectangular quatrefoil, to describe, 521

Reducing or enlarging irregular figures, 289

Reduction in bulk of materials, 557

Reeds in plaster work, 4, 28, 374, 379, 498

" Reekie " for cement, 469

Relative cost of cast and in situ modelled work, 178,
201, 209

Renovating old ceilings, 346

Replicas of works of art in fine concrete, 505

Restall's adamantine plaster quantities, 556

Reverse casting cornice mould, 382
,, moulding, 380
,, moulds for cornices, 382, 383, 384

,. » lengths of, 353

,, „ diminished fluted columns, 386

„ „ fibrous plaster cornices, 354, 356

„ „ ovals, 171

Index.

6oi

Reverse moulds for over-doors,' 390

„ „ panel mouldings, 384

,, ,, pedestals, 19S

,. ,, pediments, 390

„ „ pilasters, 386

„ „ plain caps, 385

„ „ „ columns, 389

„ „ rib mouldings, 354, 385

,, ,, templates, 169

„ moulds, wax loose piece for, 363

,, running mould, 384

„ ,, ,, loose plate for, 380-382

„ ,, ., setting out of, 38 1

„ „ „ loose piece for,

382, 384
Rims of casts, 349, 351, 578

„ moulds, 348, 350, 552, 578
Roadways, concrete, 484
Robbia, Luca della, modeller, 229
Robinson, G. T., on ancient plaster work, 1-23
„ „ gesso, 401

„ ,, sgraffitto, 212

,, stucco work by, 230

Robinson's cement, 76

,, „ tensile strength of, 76

Roman cement, covering capacity of, 557
„ „ manufacture of, 73

weights of, 557
„ ceilings, 126
„ concrete, 456
„- Corinthian entablature, 532
,, Doric entablature, 527, 529
„ Ionic entablature, 527, 530
„ law relating to the age of lime, 43
,, method of drying plaster on walls, 102
,, ,, reed lathing on wood, 102

,, mortar, loi

,, „ and Portland cement, 45

„ mouldings, to describe, 524
„ orders, 529
Rose, J., ornamental plasterer, 23, 34
Rough-cast, 210

„ quantities, 558

Run-down, meaning of the term, 578
Run-joggles, 388
Run plaster cases, 363

Running arch panels, 313; beams, 3T4; circular work,
172, 174; cornices, 108; coves, 174-177;
crown of coves, 314: cupolas, 165; dia-
gonals, 174, 177
,, diminished columns, 152
„ „ mouldings, 160

double diminished mouldings, 161, 163
„ elliptical arches, 166

Running English and Scotch methods, 108

„ Gothic ribs, 144, 146; niches, 178; ovals,
166, 168, 170; panels, 129; pediments,
191, 197; piece moulds, 382; plaster
cases, 363
Portland cement mouldings, 185
quoins, 200, 209
raking mouldings, 191, 194
reverse casting moulds, 384, 390
skirtings, 100; soffits of arches, 16S; waste
moulds, 286 ; white cements, 106; window
heads, 208
Running-moulds, 309

„ half-rib pin-mould, 146

„ hanging, 314; hinged, 294

„ making, 310 ; the various parts of,

311 ; English versus Scotch, 310
,, mufHed, 316; notes on, 316; pin,

143, 146; radius, 313; reverse,
3S1 ; twin-slippered, 313 ; with a
ball nib, 177; with a bull-nose
nib, 177
., for circular surfaces, 173-177

„ ,, concavo-convex mouldings, 335

„ „ „ surfaces, 177

„ „ concrete stairs, 492

„ „ cornices, 108, 312

,, „ diminished fluted columns, 152

„ „ double diminished mouldings,

162
„ „ elliptical arch mouldings, 169

„ ,, Gothic ribs, 143-146

„ ,, model making, 293

„ „ niches, 179

„ ,, oval mouldings, 167

,, ,, pediments, 191-197

„ piece moulds, 381-3S3
„ „ plaster cases, 363

„ „ raking mouldings, 193

,, ,, skirting, 10 r

„ „ sledge-slippered, i 7 7

,, „ square and splayed angles, 315

,, „ white cements, 106

Russian plaster work, 449
Rustication, 201
Ryestraw in plaster work, 28

C ALTER, ('■., & Co.s testing machine, 60

«-5 Sand, 52

Sand and cement, 462; Arnold's, 53; coloured, 190; for
plaster work, 444: for German Portland cement,
1S8; silver, 53 ; substitutes for, 52 ; weights, 557

Saracenic ])laster work, 420

Scagliola, 407

602

Index.

Scagliola at the Albert Hall, 409 : Buckingham Palace,
407: the Duke of Sutherland's House, 408;
Hill Head, 40S ; Northumberland House,
408 ; the Reform Club, 407 ; Whitehall,
London, 408
Bellman, Ivey, & Carter, works in, 408, 410
„ cheaper than painted work, 409
,, colours and quantities for, 414
,, columns, 411, 412

joints of, 412
„ compared with painted work, 409
„ done in situ, 407, 41 1
,, drying, 416; fixing, 408; floors, 408

(luido Sassi, supposed inventor of, 407
,, importance of chopping, 413
„ in Prance, 407; in Italy, 407
,, lasting properties of, 409
„ manufacture of, 410-413
materials for, 410-412
mixing, 413-415

light and dark, 413. 415
„ on slate slal)s, 408
,, one of the most beautiful parts of plaster

work, 409
,, plain and rich mixing, 413, 415
[lolish, e(}ual to real marble, 416
polishing, 415
„ strong water for, 413
,, the most profitable part of, 408
,, uses of, 407, 409
,, vases, turning, 412; veining for, 413
Scale of diameter, 529
„ minutes, 530
Seasoning originals, 321

Selenitic, 79; cement, 79 ; clay finish, 80; weights of, 557
Setting, 97 ; coloured, 99 ; and hardening of hydraulic

limes, 45
Sgraflfitto, 2 1 1

an economical decoration, 212, 214
and gilding, 212

„ Portland cement farades, 189
at Pompeii, 6; at South Kensington, 211
colour solution for, 513
colours for, 2 1 2
combined with fresco, 213
derivation of the word, 2 1 1
designs for borders in, 220, 221
durable decoration, 212, 214
frieze from Florence, 2 1 2

,, Rome, 213

Heywood Summer's method of working, 214
in three colours, 216

>. V and shading tints, 219

in two colours, 212

Sgraffitto panels, the four seasons, by G. T. Robinson,
214
„ retable, by G. T. Robinson, 215
,, Robinson's, G. T., method of working, 2 1 2

slabs, 377
,, used by prehistoric man, 211
,, \'asari's metliod of working, 2 1 2

Shakespeare on plasterers and plaster work, 28
Shellac, to make, 321
varnish, 331
Sheppey cement, manufacture of, 74
Siddons, Sarah, Queen of Tragedy and modeller, 334
Silicate cotton, Anderson & Son's, 373
„ ,, covering capacity of, 556

„ ,, for fibrous plaster slabs, 372

,, „ sanitary properties, 372

Sirapite, 8r ; covering capacity, 555
Skirtings, 100
Slabs of /fc/or/ww at South Kensington Museum, 102

„ „ from Pompeii, 102

Slag as a fireproof aggregate, 464
,, cement, 72
,, ,, fineness of, 73
,, ,, manufacture of, 72
„ ,, tensile strength of. Table, 73
„ wool for concrete floors, 500
Smeaton's discovery of the setting of limes, 80

,, experience in mortars, 44
Smith's nittal, 360, 398, 406
Solid work, meaning of the term, 579
Soffit enrichment, mitre of, 308

„ in the naturalistic style, 257, 327
SoflSts of arches from Rome, 437
Spanish and Moorish plaster work, 428

,, plaster work, 431
Splayed angle mouldings, to run, 315
Squaring dimensions, 560-563
Squeezing in clay, 262; mouldings, 536; wax, 251
Stage properties in fibrous plaster, 344, 345

„ papier-mache, 393

Stalactite, 428; cornice, 422; domes, 425, 427;

pendants, 428
Stamped concrete, 475

„ decorative plaster, 177, 230, 412, 438
Stamps for gesso, 401 ; for names, 481
Stearate of lime, 54
Stearic, soap, and suet solutions, 279
Steatite in plaster work, 433
Steps, Patent non-slippery, 516.
Stiffening rules, 336, 342

Straight and circular casts out of one mould, 339
Street, G. E., on Moorish plaster work, 430
Stucco, alburium or all'um opus, 101

„ ancient Greek, i ; ancient method of using, 4

Index.

603

Stucco and brick dust versus terra cotta, 8
,, „ reeds, 102 ; Austrian, 446
„ at Chenni Concha, South America, 103;
Constantinople, 102; Florence, 8; Fon-
tainebleau, 13; Haddon Hall, 31; Hard-
wick Hall, 31; Holyrood Palace, 32 ; Non-
such, 13; Peru, 103; Pompeii, 6; Raphael's
house (1513), 9; Rome, 5; Rouen, 438;
South Kensington Museum, 8 ; Venice,
103; the Palazzo Papadopoli, 103; the
Temple of Apollo, 2
,, bastard, 104

„ busts in South Kensington Museum, g
„ by Donatello, 8 ; Lombardi, 9 ; Michael
Angelo, 9; Primaticcio, 12; Romano, 10,
12; Sansovino, 9, 10; Udine, 9, 10;
Vasari, 11 ; Vittorio, 10; VoUer, 11
„ chimney-pieces, 12, 16, 438

coloured, 104, 123
•. ,- preserved with wax and oil, 102

„ common, 103; difference between plaster and,
102 ; duro, 438 ; for modelling figures, 8 ;
Italian, 437 ; koniama and kalachrisis, 102 ;
London, 103; mixed with beer, milk, eggs,
&c., 102; old, loi ; pin point, 429; Pliny
on, 2 ; primary cause of decay in, 45 ;
Raphael's discovery of, 9
„ recipes for, 2, 4, 8, 12, loi, 103
„ rough, 103; slabs as mirrors, 4, 102; staining,
104 ; statue of Bacchus in coloured, 3 ;
statues, 8, 9: trowelled, 104
Styles of English architecture, 574
Sugar in mortar, 432

„ solution for jelly moulds, 285
Sulphate of zinc for jelly moulds and plaster, 331
Sul[)hur moulds, 39S

Superficial yards rendered with Portland cement
gauged with various proportions of sand and in
various thicknesses, 557

' I ^.ALC in plaster work, 432

•*■ Technical training, use of, 551
Tectoriiim, marble plaster, loi
Templates, cast, 171

constructing, without a radius, 5 1 7
fibrous plaster, 169
for circular pediments, 197
„ fascia angles, 177
„ flat arches, 516
„ Gothic rib mouldings, 143
,, running elliptical mouldings, 168
jack, 143 ; plasterers', 545
Tenacity of concrete, 457
Tensile strength of clean and dirty aggregates, 461

Tensile strength of coarse and fine sands, 462
,, „ ,, hydraulic lime, 40

„ „ „ Portland cement and sand, 463

-, „ meaning of, 579

Terra-cotta, antiquity, of, 450

„ at Cubitt c^- Co.'s, 451, 455 ; Doulton's,

451; Fulham Pottery, 451; Etruria,
Staffordshire, 451 ; the Albert Hall,
452 ; the National History Museum,
452
„ by Bacon, Conde, Flaxman, Rhcecus,

Tinworth, Wedgwood, 451
casting, 454; clay for, 451
,, collection of art works in, 451

„ drawing for, 452 ; drying, 454 ; durability

of, 450 ; finishing, 453 ; firing, 454 ;

fixing. 455
„ geometry useful for, 452

„ Homer on, 450

„ importance of checking measurements of

models, 453
kilns for, 454
„ meaning of the word, 450

,, mitres in, 454

„ model making, 452 ; modelling for, 452 ;

moulding for, 453; pressing, 453
„ (|uantity of water for one ton of, 455

setting out, 452, 453
shrinkage, rule for, 453
the potter's wheel, 450
„ three methods for producing, 45 1

„ trade, 455

„ vases, ancient, 450, 451

„ „ worth their weight in gold, 450

work, 451
Testing coarse stuff, 44, 90

„ concrete steps, 487 ; gelatine, 318 ; glue, 318;
machines, 59 ; plaster, 37 ; Portland
cement, 56, 60-63, 69, 71
Tests of various sands and cements, 463
Texture in modelling, 227
The modeller's art, 2 28

,, Worshipful Company of Plasterers, 547
Thickness rules, 291, 540
Tile cleaning, 516; cutting, 516; fixing, 515
Timber quantities, 559

terms, 558
Tinworth, G., modeller, 226, 451
Torus, to describe the, 523
Toto, A., wax modeller, 13
Tow for fixing, 364, 367
„ in Egyptian plaster work, 422; in plaster. 441 ;
modelling, 247; rims of fibrous plaster casts, 349
Tracing paper for moulds, 569

6o4

Index.

Trammel centre, use of, 1 76

Trammels for diminished columns, 149
„ elliptical mouldings, 166

„ making, 167, 169

Transferring designs, 215, 219, 222

Transition, meaning of the term, 574

'I'rass and mortar, 44

Trefoil, to describe, 521

Triglyphs, position and use of, 528

„ setting out and constructing, 194- 196

Trowelling, a knowledge of materials useful for, 473
„ concrete, 473

„ perfection attained by practice, 473

„ soft stuff, a waste of time, 473

„ stiff stuff, a waste of time, 473

Trowelled Portland cement, 189

Truss, to draw a, 290

,, make a model of a, 290

Turkish plaster work, 424

'I'urnbats, 232, 266

Turning columns and vases, 412

Tuscan archivolt mouldings, 533
,, ca[)ital, to make a, 300
,, impost mouldings, 533
,, order, the, 529

Tympani, 191, 201

Tyzack's trowels, 545

UNDERCUTTING casts by hand, beauty of, 328
„ fibrous plaster, 353

Unskilled labour, evil elTects of, 368
Utilisation of waste products, 462

\ TALUE of plaster work, 559

* Vase, to plaster piece-mould a, 274
^'enus of Milo, the, 226
\'ermiculation, 200

Verrochin, A., and piece moulding, g
Victoria Stone Co., the pioneers of concrete slabs, 4S0
Vitruvius on damp walls, 4 ; lathing, 4 ; modelled
plaster work, 4; old stucco, 101 ; polished plaster,4
Voids in aggregates, 464
\'olute, definition of, 579

T ,T rARE, Isaac, on plaster ceilings, 21

* ' Waste moulding a bust, 262

Waste moulding for undercut mouldings, 286

„ „ in plaster, 262

„ wax moulding, 253
Water for concrete, 465

„ bad concrete caused by excess of, 490

,, bulk absorbed, Table, 480

gives birth to the strength of concrete, 466

„ measurements. 558

„ seasoned plaster moulds, 285

Waterproof centring, advantages of, 489

Wattle and daub, 14, 31

Watt's plaster models at ICaton Hall, 235

Wax casting, 251 ; cleaning, 252; covering capacity

of, 556; dissolving, 252; modelling, 246;

moulding piece, 261; jiots, 252; stjueezing,

251 ; waste moulds, 253
„ moulds, chasing, 261 ; framed, 359, 363 ; furred,

284 ; jointed, 252 ; oiling, 280 ; skin, 253
„ moulding, 252; a Corinthian capital, 299; and

plaster pieces, 359 ; bled moulds facilitates

casting, 253; fibrous plaster centre flowers,

350-352 ; fibrous plaster enrichments, 359, 363;

front, 254; method of pouring on wax, 253,

260; open front, 255; piece, 261; plaques,

261 ; surface, 257
Webb, S., on ceiling decoration, 243
Weak laths, cause of cracks in plaster, 1 10
Weatherell, J., ornamental plasterer, 19
\\'eights of concrete having various aggregates, Tabic,

557
„ various plastic materials, Table, 558
Wellings, J., on haired setting, 51
Westmacott's patent lime mortar, 64
White cements, 104

casting, 284
„ „ for concrete panelled ceilings, 499

„ „ ,, setting concrete, 494

„ ,, sanitary and fire-resisting, 104

Whitewash, brilliant, 570; cheap, 570; covering
capacity of, 556; fireproof, 570; mould-proof,
571 ; sanitary, 570; washable, 571
Whitewashers' wages (in a.d. 1212), 24
Williams Brothers & Co.'s mosaic, 483
Williams, C, stucco worker (1547), 15, 30
Wilkes and Millar's fibrous slabs, 65

patent paving, 469
Wilkinson, W. B., introducer of concrete paving, 459
Wilkinson, W. B., & Co.'s work at Newcastle-on-

Tyne, 478
Willows in plaster work, 422

Willoughby, one of the old school of plasterers, 238
Wilton, plasterer and sculptor, 34
Window apron, to form with temijlate, 209

„ heads, to construct, 208
Windows, setting out, 207
Wren, Sir C, on plaster work, 18, 33, 103
Wyatt's, Sir Digby, method of judging effects of
enrichments, 228

"W'OUNC;, B., & Co.'s Ai gelatine, 317

ERO, definilion of, 579

«\u£ mmcpn

See Notice, Page 78 in this Book.

FIRE - SOUND - CRACK - STAIN

PROOF.

Can be papered, painted, or decorated upon, without risk, at Once.

Nails can be driven into it as into a pine board ; no plugs needed ; Mouldings can
be nailed to it (see case of Carlton Hotel).

It takes a surface equal to any known Plaster.

Being a non-condiictor, buildings plastered with it are warmer in winter and cooler
in summer (see case of Mount Nelson Hotel at Cape 'I'own, built for Messrs. Donald
Currie & Co., by \Vm. Cubitt & Co.)

No Repairs, as, being fibrous, it cannot crack or fall off.

Always an advantage to be able to finish a building quickly as regards painting,
papering, distempering, or decorating.

Architects, please specify as folloivs : — ■

" The Plastering- to be executed with DANVILLE ASBESTIC PLASTER, by
the Danville Asbestic Plastering- Co.

" Plasterers' Bills priced and all information given at their offices, 27, Billiter
Buildings, Leadenhall Street, London, E.G."

For further particulars apply to

The Asbestic Manager,

The Asbestos & Asbestic Co., Ltd.,

27, Billiter Buildings, Leadenhall Street,

London, E.G.

III.

Supplied for j^ Years to the Science and Art Department of

Her Majesty s Government.

^mm

]T7r^

J^EWHRK-OJ^-TREJ^T,

MHjqUFSC-TUKEKS OF

Pk^ASTER OF PARIS, KEEJ^IE'

^cr

AJ^D PSRIAJ^ CEMEJ^'I

I^ ALL QQALlTlEg.

EslaBli^^sS. over 40 Yeapg.

laapgest ManuJ'aetupcps \n \S)e. KingcLom.

The uniform excellence of the quahty of the Goods made by us has secured for
our Manufactures a considerable and widespread reputation. We may mention that
out of the last Ibalf^a^fllMlliOll (Ions sent from tjur works, a quantity representing
IfiVe flDilliOn Sachs, not one Sack has been returned as deficient in quality.

IV.

Gypsum Mine Owners, Plaster & Cement Manufacturers, Ac.

Sole Proprietors and Manufaciurers of

SIRAPITE PLASTERING.

COARSE AND FINE PLASTER. KEENES AND PARIAN CEMENTS.

FIBROUS PLASTER SLABS FOR RAPID PLASTERING.

QROUND QYPSUM FOR MANURE. &c

Mines, Works and Offices :— MOUNTFIELD, ROBERTSBRIDGE, SUSSEX.

Address for Goods and Returned Saohs :— BATTLE STATION, S.E.Ry.
Telegrams to-"OYPSUM, ROBERTSBRIDGE STATION.'

Telegraphic Addresses: "Robinson, Carlisle"; "Stucco, London."

Gold ]V[eda<l

Telephone 1025.

X^onclon, X889.

Established 1828.

CONTRACTORS TO H.M. HOME AND COLONIAL GOVERNMENTS

War Office: Admiralty: G.P.O., Etc.

ROBINSON'S CEMENT

(Registered Trade Mark),

1885.

ROBINSON'S

SIMPLEX PARTITION

BLOCKS,

1895.

ROBINSON'S

PATENT FIRE-PROOF & HYDRAULIC CEMENTS.

(BY ROYAL LETTERS PATENT.)

Robinson's "Simplex" and "Stucco" Fire e^ Sonnd Proof Partition Blocks.

(PROTECTED UNDER THE PATENT ACTS.)

Manufactured by the Patentees,

Joseph Robinson & Co., Ltd.

SllaljaQter Projjitrtors.

Lessees of Ihe Alabaster of the Duke of Devonshire, Earl ,f Lonsdale, St. Bees' Seliool Commissioners, etc., etc.

MANUFACTURERS OF

For all purposes, and of very Superior (Quality.

KEENE S, PARIAN, & MARTIN'S CEMENTS,

Also BEST LONDON PORTLAND CEMENT supplied from Brewery Wharf, Greenwich.

SIR EYRE M. SHAW'S Testimony on Robinson's Cement.

London Fire Brigade, Southwark, S.E.
I am of opinion that this Cement would be much more effectual in preventing the sijread of fire than any
other of the common Plasters or Cements generally used in this country.

Messrs. Joseph Robinson & Co., Ltd. EYRE -M. SIIAW.

Works :-Knothill, in. Carlisle; Kirkbythore, Westmoreland ; Whitehauen, Cumberland.
Head Offices: - - - CARLISLE.

BREWERY WHARF, BRIDGE ST., GREENWICH, S.E.

London Wharf and Works:— Creek Bridge, Deptford, S.E.
London Railway Depot :—Somers Town Uoods Station, Midland Railway, N.W.

( Eiitiances Euslon and Midland Roads.)

Special facilities for Export from London (Steamers can Load along-side Brewery Wharf).
Ipviccs, Samples, aiiC» jfull ipaiticulai-s oil application.

VI.

iT-^-

'^ >r-

Fibroa6 Plaster WbrKcr,
I L^^Thwt)o^ Tmporfer and Larhrender,
C^ranolifhfc PaVeTnGn^ and Floors,
I Fireproof Ffoors and ^rhTicrciaf SfoncvVbr^, i
[ (^rani> c Cgrnen^ Slabs Tor woiii Steps a spec falfhy,

yJo(i^^ West Street,

*' AND

'%rf>of^-

Sunderland.

ESTABLISHED 1830

JOSEPH BICKLEY,

03, I^illie Raad, West Broinpton, S^aadioai S«W,

(Near Lillie Bridge.)

ARCHITECTURAL MODELLER,

PLASTERER AND CONTRACTOR.

MANUKACTURKR OF

Plaster and Canvas Enriched Ceilings, Gallery Fronts, &c.

FIRE-PROOF PLASTER SLABS AND PUGGING.

METALLIC AND GRANITE-CONCRETE PAVING AND FLOORS.

CoiKvctc 3)rc66ino, Steps, ^c.
Patent 'Mineral Black ' Covering to Walls of Tennis &> Racquet Courts.

ALWAYS A DRY COURT.

"BRIGHT COLOUR." ROUGH CAST.

VII.

ADIE'S

Cement Testing Machine.

WITH AUTOMATIC SPEED REGULATOR.

FOR PARTICULARS APPLY TO

PATRICK

ADIE,
Broadway Works,

I, Broadway, W^estminster, S.VV.

VIII.

GEO. SALTER & CO.

WEST BROMWICH,

PATENTEES AND MANUFACTURERS.

MAKERS OF

KUHLMANN'S IMPROVED CEMENT TESTER

As supplied to the British Government, Municipal and other Corporations, many

of the leading Contractors, &c. &c.

PRICE LISTS AND TESTIMONIALS ON APPLICATION.

SPRINGS for BALL=ROOM FLOORS.

Automatic Door Locks.

Wire Hat and Coat Hooks.

Patent Machine-made Gas and Water Pipe Hooks.

Patent Door Springs.

IX.

PATENT INDURATED STONE.

Patent Indurated Slab Paving.

Made by Macliiiiery, ami liaiilened ]>y the Company's Special Cliemical
Processes.

Thoroughly matured Slabs, 4/- per yard sup. at Works. Crushing Strain at
Three Mouths, 7,134 lbs. per cubic inch.

Concrete Sanitary Tubes.

In Two Feet lengths.

/Sizes.- 15 in. 18 in. 21 in. 24 in. 30 in. 36 in.

Per foot : l/gi 2/8 3/7 4/8 6/2 8 2

Tests for Porosity.

Made Ijy Messrs. Kirkaldy & Son, show an absorption of only 175
by weight.

Patent In Situ Paving,

Laid in various thicknesses, according to traffic. Tlie best, cheapest, and most
durable paving for Stables, Yards, School Plaj'grounds and Corridors,
Warehouses, etc., etc.

Staircases

Built In Situ ; and all kinds of Window Sills and Heads and other
Architectural Work kept in Stoclc or made to pattern.

MANUFACTURED BY THE

attnt Inburatcb ZL>.. Z.,, %

OFFICES, WORKS, and SIDINGS:

MILLWALL, LONDON, E

Telegrams-" PETRIFY, LONDON."

National Telephone

675 King's Cross

Telegrams —

"Slagwool, London."

FRED JONES & CO.

(Formerly R. W. HITCHINS & Co.)

MANUFACTURERS OF

FIBROUS oZr

PLASTER SLABS.

SILICATE COTTON WORKS, KENTISH TOWN,

LONDON, N.W.

Telegraphic Address — "Glue, London."

Telephone No, 724 Hop.

SPECIALLY MANUFACTURED FOR

Moulding Undercut Models,
For Casting Plaster & Cement Work.

Iimbolesale from

B. YOUNC & CO., SPA ROAD, BERMONDSEY, S.E.

RETAIL OF ALL DEALERS.

XI.

5^^^— ^*S|;.

^^laMSm

^mUmiiiiii.

W. M

BY ROYAL LETTERS PATENT, No. 7855.

P ATENT P LASTER p ECORATIQNS.

It is the only Patent Decoration with
the undercut Relief.

Fire-proof, Damp-proof, as far as any material is capable of
resistance to Fire oi Damp.

If Screwed to any surface can be removed.

Sanitary ! The Cleanest and Healthiest Material. Being
solid surface and adhered without paste, glue, &c.

All kinds of Architects' Designs Executed.

A Book oj Designs, with Price List aiui

Scale of Measurements, will be sent Free to any address in the

United Kingdom on application.

THE MURAL £ DECORATIONS SYNDICATE, \}^'

§Q> Milton Sti'a^tj E@nd.on, E,0«

xn.

GREY.
BLUE.
RED.

Yellow.

m5in\)\i

HARBUn S PLASTICINE

For Fine Art and Architectural

CLEAN! EVER PLASTIC! INDESTRUCTIBLE!

Does not shrink ; nut allV'cted hy weikT ; and ailniit.s of
(li'latine MouM.s.

I'i'unonnceil liy Iraclinu; |)i'C(iiatiiis and Scnl[)tor.>< to bo
tlie Best and Cheapest MoilcllinL,' Matmial in the
market, and yioatiy sii|ic'iior to Grea.sy Foreign I'astes.

Made ot Soft or Medium consistency.

A Specimen Pound Box (Grey) Post Free, Is. 7d.
A Liberal Discount to Purchasers in bulk

'•I lirui yciur ' riasticine' excellent." — Ko. Lauteri.

"I like ' I'lasticine ' very much — it is ailmirable." —

F. E. E. SCHBNCK.

WM. HARBUTT, A.R.C.A, Hartley House, Bath.

IMPORTANT TO PLASTERERS AND OTHERS.

PURE MANILLA FIBRE

A Perfect & Superior Substitute for Ox=liair.

ADVANTAGES :
Guaranteed not to rot or fall away when exposed to the weather, as Hair does.
More economical and more efficient than ordinai-y Plasterers' Hair.
Half the quantity of "Manilla Fibre" is required as compared with ox-hair.
It is longer and more uniform in length than ox-hair, and consequently a superior binder.
It is clean and free from dust and other foreign matters.

Tlie following Unsolicited Letters will show how highly

7. 30 .ami 41, .SIMMKI; SrilKKT. AllKUUKK.N.

We have .ilwaiB fouinl it cive preater satisfaotioii in every way tlian the
ordiuary plaitereni' hair. It likewise takes a coiisicleralile jess quantity of
Fibre to a batch of liine than the hair, and d"es not rot in the lime if exiniaed
to wet. as hair iloes. We have nsecl it on iirost of llie largest contracts iii
Aberdeen, such lus the Koyal lulirumry. Asylum, Crudeii Hay Hotel, ,Vc., Sec

It inaj be worthy of note, that the lea.liiie Architects specify "MANILLA
FiBIlK ' ill their schedules, as they prefer it far better than hair

To ourselves aud to all uur clients it has given the utmost satisfaction.
(Signed) ROGKR & BAXTER.

1S9, Belmont STKKF.r, aberdken.
" POB," or SI AXILLA FIIIRE, is an article now entirely taking the place of
hair ID this district, and its advantages are apparent.

.lA.MES UAXNOCHIE & SON'S,

Plasterers and Cement Workers.

this Material is esteemed hy leading Plasterers :—

55. John stueet, Aberdeen.
We have great pleasure in certifying that we have used Manilla Fibre
aud find it to be much more profitable, as it only takes about uue-half quantity
of Manilla to a batch of lime to that of hair, and does not rot in lime when
exposed to the weather

Manilla is now used in the erectiou of all the principal buiidiugs, aud
Architects specify this material to be used instead of hair.

(Signed) JAMES SCOTT k SO.V,

Contractors, Plasteiers, aud Cement Workers.

148a & 160, HUTCHEON .STREET WEST, ABERDEEN.

We certify that we have used MANILLA Fibre, as manufactured by you,
for the last 12 months, and have found it very satisfactory, more so than the
ordinary plasterers' hair, and not so liable to rot, and goes as far as 13 of the hair.
(Signed) .STEPHEN & GIBB,

Plasterers and Cement Woikers.

MANILLA FIBRE is also specially recommended by JOHN RUST, Esq , City Architect; and is specified
by A. MARSHALL MACKENZIE, Esq., Messrs. BROWN & WATT, ARTHUR CLYNE, Esq.,

and other eminent Architects.

Full Particulars, Samples, and Prices Free on application to the Sole Maher,

JOHN HALL, Aberdeen Rope Works, Footdee Links, ABERDEEN.

XIII.

' ^^■,f'^^^,^/^^^,^^^/^^'^^^>^^^/^^>W^>'^i^^Pk^-y^^y^7^^<^>'s^i^

fi II II

i jgyV I

9BC=B

" " " ~"

J.WIU50N &i Son.

Plasterers ^ Concreters

^ Fibrous Plaster ^ Tile WbrKers.

CRANiric Paving for Streets. Stables. Miuus «»c

"55 VOOD SrREET^^^^^j^i^^j^^

\i;B^ttai^_^

r M^^'^'mf

Late T. Drew & Son,

FEAIH AND ORl^AMENTAI, P^ASTERKR,

AND

FIBROUS PLASTER MANUFACTURER,

68, Richmond Road, Islington, London, N.

MODELLERS AND MANUFACTURERS OF

Ornamental fibrous [Plaster and Oarton=3?ierre.

DECORATIVE PAINTERS & DESIGNERS.

84, ALBERT STREET, CAMDEN TOWN, LONDON, N.W.

NELSON'S GELATINE

FOR

MOULDING AND PLASTERER'S WORK.

Nelson's Photographic Gelatine.

Retail fi'om all Dealers. Wholesale only iron-i the Manufaetui^ers,

GEO. NELSON, DALE & CO,, Limited, 14, Dowgate Hill, London, B.C.

XIV.

112, ii3» Fore Street, London, E.C.
JUTE, HEMP, AND FLAX MERCHANTS.

SPECIALTY- CANVAS

Of all Desci-ipLions lor Fibi'ous-Plastering, Building, Paper-Hanging, &c.

Samples an& ipricc Xlsts on Bppllcatiou.

Telegraphic Address "Yarnless, London."

Clifton ni^osaic Ziic, Ciitton Hitificial Stone (^^S.^'^)

Cheap, Durable, and Non-Slippery, for Footpaths, Playgrounds, Warehouses, Corridors, Stables, Tennis
Courts, Steps, Landings, c^c, c>'c. Stone Moulded to any Design.

ASPHALTE MANUFACTURERS AND CONTRACTORS.

WORK GUARANTEED FOR LONG PERIODS.

A. C. W. HOBMAN & CO.,

Contractors to Her Majesty's Government, Sole Contractors to tlie London School Board, Tlic London County Council, Metropolitan
Asylums Hoard, Peah'Kh' Donalioii Trustees, :ind tlie principal Innards of Works round London and elsewhere.

CLIFTONVILLE, SOUTH BERMONDSEY, LONDON, S.E.

Telegraphic Address ; -HOBMAN. SOUTH BERMONDSEY. Telephone No. 1241 HOP.

ANTISEPTIC PLASTER FIBRE.

SUBSTITUTE FOR CO^V-HAIR.

More Effective, More Durable, More Economical than Cow-Hair.
TP^opouighjllj Antiseptic, Free fporr^ all tJ^e Irripupities of ■Hair.

Stroii(j< r <(i(i/ hunx' reliable than Hem'. Strenyth nut inqjaircd by actinii of Lime.

ROBERT BAXTER &, CO.,

/IDamifactuicrs,
64 &c 66, BELL STK.EET, nDTJn^LEEl.

PETER FORD & SONS,

MANUFACTURERS OF ALL KINDS OF

KEEXE'S, PARIAN & MARTIN'S CEMENT.

ALABASTER and stone merchants.

Alabaster, White or Coloured, in Blocks for Architectural Purposes. Turned work of every description.
Ornaments. Uypsum Stone for Rockeries, Vineries, &c. &c.

MINES AND MILLS -FAULD, NEAR TUTBTJRY 1

STONE aUARRIES-ALTON & STANTON ' NORTH STAFFORD RAILWAY.

Offices: BRIDGE STREET UTTOXETER.

Telegrams " FORDS, UTTOXETER."

National Telephone No. 2. Alabastcp Blocks Quarried up to 14 feet in Length.

XV.

Teeth Cut out ofSoHii.

28, EGLINTON STREET, GLASGOW,

Makes a Speciality of all kinds of Granolithic or Concrete.

Brass Pavement Rollers & Name-Plates.

special Machinery for their Manufacture.

Stable Rollers & Grooves. Hand Stamps, Border Rollers
and Crimpers.

PAVEMENT NAME-PLATES, ANY NAME & SIZE,

Suitable for Builders, Contractors, Plasterers, and Concrete Workers.
SEND FOR ILLUSTRATED LIST.

RAILWAY ARCH, 343 & 345, OLD STREET, E.C.,

riDanufactuvcv of plastevcvs' XTools of all IDcscviptions.

TROWELS, SMALL TOOLS, JOINT RULES, ETC.

SAIVIUEL TYZACIi'S

Er)GE TOOL, FILE & CXJTLEHY TVAHEHOXJSES

Steam Grinding- IWills— 343 & 345, OLD STREET, LONDON, E.G.

ESTABLISHED OVER TWENTY YEARS. BEST MEDIUM FOR TRADE ADVERTISEMENTS.

XVI.

WILLIAM MILLAR,

PLASTERER, MODELLER, AND CEMENT EXPERT.
Analysis made of Portland Cement, Limes, etc.

Specialities

Modelling, Fibrous Plaster, Scagliola,
Sgraffito, Gesso.

AGENT FOR

MANILLA FIBRE (a Perfect Substitute for Ox-Hair), Gelatine and Fibrous Plaster Materials.

Moulding Pieces of Modern Enricliment Supplied to the Trade.
Postal Address: 94, HIGH HOLBORN, LONDON.

Practical Books for Plasterers, Builders, Decorators, etc.

Qi,

Building Construction & Drawing.

I'lKsr Stac;e, or Ei.kmkntauy Couk.si;. By
Ch.\rles F. Mitchell. With 310 pp. and nearly 700
Illustrations, fully dimensioned. Fourth Edition (19th
Thousand). Cr. 8vo, cloth, Price 31. Net 2S. (>d.

Building Construction. Advanced and

Honours Courses. By Ch.^rles F. Mitchell.
Containing 552 |)|). of Text, with over 2S0 Illustra-
tions. Second Edition, Revised and Enlarged (7th
Thousand). Cr. 8vo, cloth. Price 5/. (ii/. Net 4^. 6(i.

" So far as it is possible for .any one to compile a satisfactory' treatise
on building construction, Mr. Mitchell li.xs pcribrmed the task as well as
it can be i«rformed." — The liuihhr.

uantities. A Text-Book e.\planatory of
the best methods adopted in the measurement of
builders' work, and containing many useful hints
and much valuable information. By Professor
B.XNiSTER Fletcher, I'.R.LH.A. Sixth Edition,
With 16 Folding Plates and numerous Illustrations
in the text. Crown 8vo, cloth, Price 75. dd. Net 6.f.
The .most Complete, Concise, and Handy Work on
1 HE Subject.

Estimating. A Method of Pricing
iJuilders' Quantities for Competitive Work. By
(■ )RGE Stephenson. Showing how to price,

..hout the use of a Price Book, the Estimates of
he work to be done in the various building trades.

.lird Edition, the Prices carefully revised to date.
Crown 8vo, cloth, Price ds. Gd. Net 5^. bd.

Repairs : How to Mea.surc and Value
them. By the Author of " Estimating." Second
Edition, revised. Cr. 8vo, cloth. Price 3^. bd. Net y.

The Conduct of Building Works

and the Duties of a Clerk of Works. By
J. Leaning, F.S.I. Containing 140 pp. Small
Crown 8vo, cloth, Price 2S. (td. Net 2s.

Specifications. For the use of Builders.
Architects, and Surveyors. By J. Leaning, F.S.I.
Second Edition, revised and enlarged. Crown 8vo,
Price :\s. Net t,s. 4d.

Dictionary of Terms used in Build-
ing Construction aud Architectural Design. Giving
Practical Descriptions, with Technical Details. By
R. S. Burn, Author of "The Guide to Masonry,"
&c. Containing nearly 300 pages of Text and 38
full-page Plates. Large 8vo, Price ^s. Net 4^.

House Drainage. ByG.A.T.MiDDELxoN,

A.R.I.B..\. and M.S.A., Author of "Stresses and

Thrusts." Illustrated by 22 Plates and Diagrams.

Second Edition, revised. Crown 8vo, cloth. Price
^s. Gd. Net 3J.

Stresses and Thrusts. By G. A. T.

Middleton, A.R.I.B a. Illustrated by 89 Diagrams.
Crown 8vo, cloth. Price 5^. Net 4^.

Dangerous Structures, and how to

deal with them. A Handbook for Practical Men.
By Geo. H. Blagrove. Crown 8vo, cloth, Price
T,s. Net 2S. Gd.

Concrete : Its Use in Building. By

Thomas Potter. Second Edition, greatly enlarged.
Crown 8vo, cloth, containing 500 pages of Text and
100 Illustrations. Price is. Gd. Net Gs. Gd.

A Handbook of Ornament. With 300

plates, containing about 3,000 Illustrations of the
Elements and the Application of Decoration to
objects. By F. S. Meyer. Third English Edition,
'I'hick 8vo, cloth gilt, Price 1 2S. Gd. Net ()S. Gd.

" A LiBUAitv, A Museum, AN EncycloPvEdia, and an Art School
IN ONK. To rival it as a book of reference one must fill a bookcise." — The
Studio.

Any of the above Works will be forwarded POST FREE on receipt of the Cash Discount Prices Quoted.

B. T. BATSFORD, 94, High Holborn, London, W.C.

University of California

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