Ex Libris 
 C. K.OGDEN |

 
 THE CAMPANILE AT PISA 
 3/ieH>eruf tiie suAsidtfUZ* (fete Sbundatom,; 
 
 Jolm. Williams . Library of Arts . Great Rufsell Street Bloomsbury
 
 THE 
 
 ARCHITECT, ENGINEER, 
 
 AND OPERATIVE BUILDER'S 
 
 CONSTRUCTIVE MANUAL; 
 
 OR, A 
 
 PRACTICAL AND SCIENTIFIC TREATISE 
 
 OS THE 
 
 CONSTRUCTION OF ARTIFICIAL FOUNDATIONS FOR 
 BUILDINGS, RAILWAYS, &c. 
 
 WITH A COMPARATIVE VIEW OF THE APPLICATION OF PILING 
 AND CONCRETING TO SUCH PURPOSE; ALSO AN INVESTIGA- 
 TION OF THE NATURE AND PROPERTIES OF THE MATERIALS 
 EMPLOYED IN SECURING THE STABILITY OF BUILDINGS. THE 
 WHOLE ILLUSTRATED BY EXAMPLES SELECTED FROM THE 
 MOST IMPORTANT ARCHITECTURAL AND ENGINEERING WORKS 
 OF THIS COUNTRY. 
 
 TO WHICH IS ADDED, 
 
 AN ANALYSIS OF THE PRINCIPAL LEGAL ENACTMENTS AFFECTING THE OPERATIONS 
 OF THE PRACTICAL BUILDER. ILLUSTRATED BY NOTES OF CASES OCCURRING 
 IN ACTUAL PRACTICE. 
 
 BY CHRISTOPHER DAVY, 
 
 ARCH. & C.B. 
 
 SECOND EDITION. 
 
 LONDON : 
 
 JOHN WILLIAMS, LIBRARY OF FINE ARTS, 
 
 106, GREAT RUSSELL STREET, BLOOMSBURY. 
 
 1839.
 
 DRURY, PRINTER, 
 
 18, Took's Court, Chancery Lane, London.
 
 ADVERTISEMENT 
 
 TO THE SECOND EDITION. 
 
 THE author of the following treatise is happy to 
 avail himself of the present opportunity of tendering 
 his respectful acknowledgments to the members 
 of the Architectural and Engineering professions, 
 and to the public generally, for the very flattering 
 manner in which the first part of the " Manual " 
 has been received. The very rapid sale of the work, 
 and the still increasing demand for it, have more 
 than realised the anticipations of the author. 
 
 A second edition having been called for, the 
 writer has been enabled to make such corrections 
 and improvements as have appeared desirable, and 
 which, he hopes, will render it more worthy of the 
 approbation of those for whose use it has been 
 written. The success of the first edition having 
 assured the author of the support of the pro- 
 
 2017708
 
 VI 
 
 fession, he naturally feels greater confidence in the 
 task which he has undertaken, and is stimulated 
 to exert his utmost endeavours to retain so honour- 
 able a mark of distinction. 
 
 In consequence of the vigorous condition of 
 engineering practice, the author considered that a 
 correct analysis of those mineral substances which 
 comprise the greatibt portion of building materials 
 would add materially to the practical value of the 
 work. For this purpose, he has made a collection 
 of British specimens, and has subjected them to 
 minute chemical analysis. The result of these 
 examinations will be given in the forthcoming 
 part ; and it is hoped that the information thus 
 laid before the profession will prove to be of con- 
 siderable importance. The second part will contain 
 chapters on the following subjects : 
 
 1 . On the sands of the plastic clay formation. 
 
 2. On the analysis of the principal mineral 
 substances employed in building. 
 
 3. On concrete, asphaltic, and other cements. 
 
 4. The construction of foundations on various 
 soils. 
 
 5. On the machines and scaffolding used in 
 excavating and building.
 
 Vll 
 
 6. Description of machines for proving the 
 strength of materials, 
 
 7. On railway works and estimates. 
 
 The whole of the chapters in the second part 
 will be fully illustrated with original drawings 
 explanatory of the text. The liberal patronage 
 bestowed upon the first part of this treatise has 
 induced the publisher, Mr. Williams, to secure the 
 talent of Mr. T. C. Dibdin, whose pencil will be 
 employed (under the direction of the author) in 
 delineating some views (taken expressly for this 
 work), illustrative of the geological formations of 
 this country, and also of important railway works, 
 showing the progress of their construction. The 
 analytical portion of the work having occupied a 
 greater length of time than was originally contem- 
 plated, it was considered indispensable to publish it 
 in parts to prevent greater delay. The author 
 trusts that this explanation will atone for the slight 
 breach of his original engagement. 
 
 C. D. 
 
 No. 3, Furnival's Inn, 
 24th Jan., 1839.
 
 CONTENTS >F PART I. 
 
 A REGISTER 
 
 Page 
 
 Of the principal Geological Formations in each of the Counties 
 of England and Wales, with Observations on the Quality of the 
 Materials to be derived therefrom, and applicable to the purposes 
 of Building ; also, the situation of the principal Stone Quarries, 
 Lime Works, &c, v 
 
 CHAPTER I. 
 
 Preliminary Observations. Remarks on the General Order 
 and Succession of Strata. On the Examination of Strata, and 
 Description of Boring Apparatus employed for that purpose. 
 Nature of Strata above the London Clay. Sections of Strata in the 
 neighbourhood of London, &c f 
 
 CHAPTER II. 
 On Pile Driving and Piling 35 
 
 CHAPTER III. 
 
 On the Nature and Application of BETON. Translated from 
 " BELIDOR ARCHITECTURE HYDRAULIQUE." 75 
 
 . 
 
 CHAPTER IV. 
 
 On the Analysis of Limestone 94 
 
 CHAPTER V. 
 
 On the Calcination of Limestone. Observations on British 
 Limestones Action of Acids thereon, &c 116 
 
 CHAPTER VI. 
 
 , On the Proportion and Admixture of Ingredients employed 
 in the Composition of ordinary Mortar. Quality of Sands, Sand- 
 tones, &c. . i* . -'. 156
 
 ADVERTISEMENT. 
 
 THE ramification of railways throughout the king- 
 dom has so extended the sphere of the engineer's 
 operations, as to render a knowledge of the geolo- 
 gical formations peculiar to each county through 
 which his passage lies, of considerable, nay, of essen- 
 tial importance. Geological knowledge is now to 
 the engineer indispensable, inasmuch as it forms the 
 source from which his supplies must be drawn, and, 
 at the same time, forms the index by which may 
 be ascertained the nature of that foundation upon 
 which his construction is to rest. 
 
 In the ordinary routine of architectural prac- 
 tice, it is notorious that information of this kind has 
 been rarely sought for until the time has arrived for 
 carrying the intended works into execution. The 
 uncertainty and delay incident to this mode of 
 inquiry has not unfrequently entailed ruinous con- 
 sequences upon both architect and builder. If proofs 
 were wanting, we should be prepared to show from 
 specifications on the one, and breach of contracts 
 on the other side, instances of defective informa- 
 tion, and consequent difficulties and extravagance of
 
 execution, fully corroborative of this opinion. It is 
 evident therefore, that the engineer should be pre- 
 pared with such information as will enable him to 
 avail himself of the resources of each particular 
 district, and to apply them with promptitude and 
 decision. 
 
 The calcareous and siliceous deposits of this 
 country have hitherto received but little attention 
 from the profession ; and we may add, that with 
 respect to the nature and properties of the materials, 
 we are as yet " upon the threshold of our know- 
 ledge." 
 
 The great and increasing demand for geolo- 
 gical information applicable to architectural and 
 engineering purposes, has induced the author to 
 prefix to the following Treatise a Register * of the 
 principal geological formations in each of the coun- 
 ties of England and Wales, with observations on 
 the quality of the materials to be derived therefrom, 
 and applicable to the purposes of building; also, 
 the situation of the principal stone quarries, lime 
 works, &c. 
 
 In compiling this " Register," the author has 
 attempted to give a concise view of the resources of 
 each county, in order that the draft of the specifi- 
 cations for important works may be made with 
 
 In consequence of the extent occupied by this additional matter, 
 (which has much exceeded our original plan,) the " Introduction," 
 which is chiefly historical, is deferred till the publication of the second 
 part of the " Treatise."
 
 Ill 
 
 greater accuracy than heretofore, and that the 
 builder may be directed to the sources from which 
 he may obtain his materials with facility and 
 economy. 
 
 To trace the extent and disposition of the strata, 
 the engineer must necessarily consult an accurate 
 geological map ; for this purpose, the " Index Map," 
 by J. Philips, Esq., F.R.S., G.S., and the large 
 map by Messrs. Walker, will supply much valuable 
 information. 
 
 The reader will perceive, from the authorities 
 which are given, that the author has, in the following 
 compilation, freely availed himself of such informa- 
 tion as was afforded by reference to the works of 
 the most eminent writers on geological science ; and 
 having, also, visited and carefully examined most 
 of the northern and western counties of England 
 during the last two summers, he trusts that the 
 variety of facts and data thus collected and brought 
 under immediate observation, may meet with the 
 approbation of the members of that profession to 
 which he has the honour to belong. 
 
 3, Furnivul's Inn, Nov. 1838.
 
 A REGISTER 
 
 OF THE PRINCIPAL GEOLOGICAL FORMATIONS IN EACH 
 OF THE COUNTIES OF ENGLAND AND WALES, WITH 
 OBSERVATIONS ON THE QUALITY OF THE MATERIALS 
 TO BE DERIVED THEREFROM, AND APPLICABLE TO 
 THE PURPOSES OF BUILDING ; ALSO, THE SITUATION 
 OF THE PRINCIPAL STONE QUARRIES, LIME WORKS, &c. 
 
 Northumberland. 
 
 THE county of Northumberland contains, 1. Moun- 
 tain or carboniferous limestone. 2. Coal. 3. Basaltic 
 and porphyritic trap. And, 4. Old red sandstone, 
 with the accompanying beds of conglomerates, grit- 
 stones, variegated marls, and cornstones. 
 
 The building materials supplied by this county 
 chiefly consist of limestone, limestone marble, and 
 sandstones. The quarries are plentifully distributed 
 throughout the county. Limestone abounds in the 
 districts of Bamborough Ward and part of Glen- 
 dale Ward, east of the river Till ; it is also quarried at 
 the following places Sprouston,Stodridge,Shilbot- 
 tle, Long Franlington, Hartburn, Ryall, Corbridge, 
 and Aldstone Moor. Blue, red, gray, and brown 
 whinstone is procured from Bamboroughshire, the
 
 VI 
 
 Cheviot mountains, and adjacent places. It is 
 generally employed for repairing the roads. 
 
 The limestones of Northumberland vary con- 
 siderably in quality ; they may be classified in the 
 following order: 1. Highly crystalline. 2. Slightly 
 crystalline. 3. Ferruginous. 4. Bituminous. And, 
 5. Calcareo-siliceous. The strongest lime is to be 
 obtained from the calcination of Nos. 3 and 4. The 
 crystalline varieties are best adapted for wrought 
 masonry or architectural fa9ades. For engineering 
 works, or the substructure of important buildings, 
 the sandstones, associated with the carboniferous 
 deposits, are highly valuable. The following are 
 the varieties: 1. Slate sill a fine-grained mi- 
 caceous, slaty rock, of a gray colour, used as a 
 roofing slate in many villages of Northumberland 
 and Durham. It is the uppermost bed in the section 
 of Heley field. 2. Freestone sills fine-grained 
 quartzose sandstones, used for building. 3. Hazles 
 hard, ferruginous, fine-grained sandstones. 4. Mill- 
 stone grit a coarse, white, quartzose sandstone ; it 
 crops out on the Derwent, and is quarried for mill- 
 stones. The quarries are at Muggleswick Fell, and 
 between Wolsingham and Stanhope, in Weardale. 
 A similar rock is found at Scrainerstone, in the 
 north-eastern part of Northumberland, and at Craster, 
 near Howick. The castle of Dunstanborough is 
 built with this stone. 5. Grindstone sill a fine- 
 grained yellowish sandstone found at Alstone Moor 
 (Durham), Coalcleugh, Allenheads (Northtimber-
 
 VII 
 
 land), Nenthead, and on the summit of Cross Fell. 
 The grindstones made from this material are said 
 to be much inferior to those of Newcastle. 
 
 Below the limestone, in the Aldstone Moor 
 section (Durham), are the following sandstones : 
 
 1. Whetstone sill a fine-grained micaceous sand- 
 stone, at Burtreeford. 2. Ironstone sill a ferrugi- 
 nous sandstone, containing an abundance of iron 
 pyrites. 3. Firestone a fine-grained, porous sand- 
 stone, used for furnaces. 4. Pattisoris sill a very 
 hard, gray sandstone, containing mica. 5. The 
 coal sills similar to the above. And, 6. Water sill, 
 or tuft a very porous, soft, light-coloured sand- 
 stone. 
 
 The durability of sandstone chiefly depends 
 upon its texture or state of induration. It has been 
 remarked,* that when a porous sandstone is exposed 
 to the weather, or placed in such situations where 
 water may enter and penetrate its crevices, mere 
 change of temperature will cause much misfihief ; 
 but on the occurrence of a frost, the expansion be- 
 comes so great, that a single winter may cause a 
 disaggregation of the entire mass. 
 
 Durham. 
 
 The county of Durham contains, 1. Coal. 
 
 2. Millstone grit. 3. Magnesian limestone. 4. 
 Mountain limestone. And, 5. Trap. 
 
 See Brande's Journal, vol. iii. p. 381.
 
 Vlll 
 
 The great limestone of Frosterley, in Weardale 
 (Durham), is a dark gray shelly marble, extensively 
 quarried for lime, ornamental purposes, &c.; it con- 
 tains 96 per cent, of carbonate of lime. The scar lime- 
 stone is similar to the above ; it crops out in the 
 Nent rivulet. The cockle-shell limestone a dark, 
 iron-gray, shelly limestone; it crops out on Aid- 
 stone Moor. The Tyne-bottom limestone an encri- 
 nal limestone of three strata ; it forms the bed of 
 the Tyne for four miles, from Tyne Head to Garri- 
 gill Gate. Robinson's great limestone and the Mel- 
 merby scar limestone, are carboniferous beds of con- 
 siderable thickness ; the former is the lowest in the 
 Dufton section, and the latter bassets out at Mel- 
 merby Cliff. At this place the bed is twenty-one 
 fathoms in thickness. An account of the magnesian 
 limestone of Durham, and an analysis of some 
 specimens will be found in the 4th chapter of this 
 Treatise. Magnesian limestone, when calcined, pro- 
 duce* lime possessing peculiar properties, which are 
 hereafter noticed. As a material for masonry, it 
 is much superior to the tender oolitic varieties of 
 the west of England. The atmosphere acts with 
 much less intensity upon the fine-grained and mag- 
 nesian limestone than upon the coarser and oolitic 
 kinds. The superficial hardening which takes place 
 upon the surface of the Bath oolite, when exposed 
 to the weather, is very deceptive, inasmuch as it is 
 followed by a rapid disaggregation of the stone. 
 The Castle of Clare, in the county of Suffolk, is in
 
 IX 
 
 part built with magnesian limestone. A portion 
 of one of the bondstones from the keep of that 
 structure, was procured by the author during the 
 past summer. Upon examination it was found 
 nearly perfect, while a specimen of oolite from the 
 same building crumbled to calcareous sand. This 
 building was erected some time previous to the year 
 1190. 
 
 The millstone grit and other sandstones of 
 the county of Durham do not differ materially from 
 the sandstones of Northumberland already described; 
 such variations as occur being more interesting to 
 the geologist than to the engineer, we omit any 
 further notice of them. 
 
 The sandstone from the Heddon (Heddon- 
 on-the-Wall) quarries, Northumberland, must not, 
 however, be omitted in our Register. This stone is a 
 hard, light-coloured quartzose sandstone, with rather 
 a coarse grain, but admirably adapted for engineer- 
 ing works. Some of the earliest edifices in the 
 county, constructed with this stone, yet remain to 
 attest its durability. 
 
 The quarries recently opened at Heddon 
 communicate with the Tyne river by a railway. 
 The basalt, graywacke, new and old red sandstone, 
 &c., are chiefly worked and employed for local pur- 
 poses. The other materials will be described in the 
 account of those counties where such formations 
 assume a greater importance.
 
 Cumberland. 
 
 Cumberland contains, 1. New and old red 
 sandstone. 2. Trap. 3. Granite. And, 4. Clay 
 slate. The principal free stone quarries (chiefly red 
 and white siliceous and quartzose grits), are in the 
 neighbourhood of Whitehaven ; from whence it is 
 shipped to various places. Quarries for grindstone 
 grits are situated near Ivegill and Barngill. The 
 blue slate quarries are at Bassenthwaite, Borrow- 
 dale, Buttermere, Cockermouth, and Ulpha. In 
 this county there is also coal and its accompanying 
 limestone, but the principal deposits from which 
 building stone is drawn are the new and old red 
 sandstone formations. 
 
 Westmoreland. 
 
 Westmoreland contains formations similar to 
 the above, with the addition of a development of 
 the Silurian system. These rocks furnish, 1. Mica- 
 ceous sandstones, limestones, and sandy shales. 2. 
 Subcrystalline limestone shale. 3. Gritstones, then 
 limestones and sandstones. And, 4. Calcareous and 
 argillaceous flags. The prevailing stratum of 
 the southern and eastern parts of the ^county is 
 carboniferous limestone, associated with quartzose 
 grits. Limestone marble is quarried within three 
 miles of Kendal, also near Ambleside, and a bitu- 
 minous limestone near Kirby Lonsdale and Ken-
 
 XI 
 
 dal Fell. The great slate quarries occupy the 
 western mountains. A valuable quarry of fine blue 
 slate (the property of Lord Lowther) is worked at 
 Great Langdale, and is known as the " Thrang Crag 
 slate quarry." Whinstone or Whintin (a slaty flag- 
 ging, containing a small proportion of mica), and 
 slate is also procured from the north western moun- 
 tains. The dark gray limestone of Windermere 
 and its vicinity is quarried for lime, chimney pieces, 
 &c. ; red felspathic granite, and another variety, much 
 harder, and of a green colour, occurs at Wasdale. 
 The specific gravity of Westmoreland slate varies 
 from 2797 to 2732 ; it is blasted from the quarries 
 in large masses, and afterwards split and dressed, 
 chiefly by hand.* 
 
 Yorkshire. 
 
 Yorkshire contains, 1. Coal. 2. Millstone grit. 
 3. Carboniferous limestone. 4. Trap. 5. Moun- 
 tain and magnesian limestones. And, 6. Clays and 
 crag. Building materials may be obtained as fol- 
 lows. Quarries of freestone and millstone grit are 
 to be found at and near Gatherley Moor, near 
 Richmond, Renton near Boroughbridge, west of 
 Sheflield, Penistone, Huddersfield, Bradford, Otley, 
 Harrowgate, Ripley, Masham, Rainton quarry, 
 
 * A particular account of the several varieties of slate, with the mode 
 of working the quarries, machinery for cutting slate, &c., will be found 
 in the second part of the "Treatise."
 
 Pateley quarry, Moorstone quarry, all within a few 
 miles of Ripon. Quarries at Bramley, Mexborough, 
 Holton, Kirby, Leeds, Idle, and Sheffield ; all these 
 are quartzose grits. Magnesian limestone quarries, 
 Brodsworth, Quarry Moor, Ripon, and at Doncaster. 
 Mountain limestone quarries Roach Abbey and 
 near Richmond, &c.* Limestone and marble are 
 also found in the Western Moorlands. A roofing 
 flag slate (siliceous) is dug near Wensleydale. 
 Lias is sufficiently near to ba procured for lime. 
 
 Lancashire. 
 
 Lancashire contains, 1. Coal. 2. Millstone 
 grit. 3. Mountain and magnesian limestones. 4. 
 New red sandstone. The quarries of freestone 
 are situated in that part of the county south of the 
 sands. Flagstones are also raised in the same 
 district. Blue slate quarries are most numerous 
 in the northern parts of High Furness. 
 
 * The prices of Roche Abbey and Brodsworth stone for the present 
 year, 1839, are as follows : 
 
 Roche Abbey (best) 16 to 18 pence, per foot cube-. 
 
 Ditto (inferior) 12 to 14 ditto ditto / Shipped at 
 
 Brodsworth (best) 12 pence ditto i Doncaster. 
 
 Ditto (inferior) 9 ditto dittQ ) 
 
 There are several other limestone quarries in the vicinity of Roche 
 Abbey and Brodsworth, but the blocks of stone procured from them 
 are of inferior dimensions. The best Roche Abbey stone is not much 
 inferior to white marble in closeness of grain ; it is consequently well 
 adapted for monumental works, carving, &c.
 
 xni 
 
 Anglesea. 
 
 Anglesea contains, 1. Gneiss. 2. Mica schist. 
 3. Granite. 4. Coal. 5. Old red sandstone. 6. Car- 
 boniferous or mountain limestone. 7. Trap. And, 
 8. Clay-slate. 
 
 The quarries of the Isle of Anglesea have fur- 
 nished a crystalline limestone, which appears well 
 adapted for architectural facades ; its use, however, 
 has as yet been very limited, arising probably from 
 the expense of carriage or freight. The most noted 
 edifice erected with this material is the Birmingham 
 Town Hall. 
 
 Caernarvon. 
 
 Caernarvon contains, 1. Graywacke. 2. Trap. 
 3. Gneiss. And, 4. Mica schist. 
 
 The great bulk of building materials employed 
 in this country is derived from calcareous and 
 siliceous deposits. The peculiar nature and com- 
 position of the primary rocks prohibit their employ- 
 ment for the ordinary purposes of building; in 
 England, therefore, the supply drawn from these 
 sources is almost exclusively confined to granite and 
 slate. The county before us, and most others in 
 the principality of Wales, exhibit these formations 
 in considerable grandeur ; we accordingly take this 
 opportunity to offer a few general remarks on the 
 structure and composition of the primary system of
 
 XIV 
 
 rocks, or at least such of them as appear to com- 
 mand the particular attention of the engineer. The 
 primitive rocks are, by geologists, usually classed as 
 follows: 1. Granite. 2. Gneiss. 3. Mica slate. 
 4. Clay-slate. 5. Primitive limestone. 6. Primitive 
 trap. 7. Serpentine. 8. Diallage rock. 9. Porphyry. 
 10. Quartz* 
 
 The constituents of common granite will be 
 found in the sixth chapter of this Treatise ; on this 
 subject it is only necessary to add, that the propor- 
 tion per cent, of oxygen contained in this substance, 
 and the particles of which it is composed, according 
 to Mr.'De la Beche, are as follows: 100 granite = 
 52 metallic bases + 48 oxygen. 100 quartz = 
 48.4 metallic + 51.6 oxygen. 100 felspar = 54 
 metallic bases + 46 oxygen. 100 mica = 56 me- 
 tallic bases + 44 oxygen.f (See De la Beche's 
 Geological Manual, 2nd edition.) 
 
 According to its locality, granite is known by 
 various names; thus in Corn wall it is usually called 
 " moorstone" (Smeaton) ; in Scotland, whinstone or 
 sandstone (Jamieson), while among antiquarians the 
 
 * " Jamieson's Mineralogy." For an account of the subdivisions 
 of these rocks and other geological information concerning them, the 
 reader is also referred to that work; " Philip's Treatise on Geology," 
 vol. i. ; and " De la Beche's Geological Manual." 
 
 f Quartz is a compound of a metallic basis, silicium, and the air or 
 gas oxygen. Felspar is a compound of silkium, calcium, potassium, &c., 
 each united with its own proportion of oxygen. Mica is a compound 
 of silicium, potassium, magnesium, calcium, &c., similarly combined with 
 oxygen. (Philips's Treatise on Geology, vol. i. p. 31.)
 
 XV 
 
 term granite has been applied to every rock possess- 
 ing a granular structure. Popular opinion has con- 
 ferred upon this material a character for durability 
 exceeding every other kind of stone; it is nevertheless 
 subject to rapid disaggregation and even decay, in 
 proportion to the quantity and quality of its consti- 
 tuents. From numerous observations derived from 
 chemical and mechanical experiments, it appears 
 that the particles of granite most acted upon by 
 the atmosphere, are those which form the great 
 mass of its composition, namely, felspar. 
 
 In judging the quality of a building stone we 
 may rest satisfied that the greater the quantity of 
 argillaceous or earthy matter contained in it, the 
 more certain and rapid will be its decomposition. 
 Felspar appears to be a substance of an earthy or 
 argillaceous character ; thus, if we finely pulverize a 
 portion of felspar, and add a small portion of water 
 to the powder, we produce a paste forming a tolera- 
 ble substitute for clay;* and it has been remarked,f 
 that clay -slate " is not very distinct, chemically 
 speaking, from decomposed felspar which has lost 
 or changed the condition of its potash by the opera- 
 tion of water." " Hence," continues Mr. Phillips, 
 " under particular circumstances (which permit the 
 access of alkali and great heat) that blue slate is 
 actually transformed to white and glassy crystalline 
 
 * See " Philips's Treatise on Geology," p. 124. 
 t Ibid.
 
 XVI 
 
 grains of felspar :" this discovery was made by Mr. 
 W. V. Harcourt, of Yorkshire. 
 
 Although this granitic compound is, per se, 
 liable to premature decay, it cannot be denied that 
 granitic rocks offer greater resistance to the action 
 of the atmosphere than most others. The difference 
 of quality observable in granites is very striking ; 
 the coarse grained granites of Devon and Cornwall, 
 compared with the finer grained and harder kinds of 
 Aberdeen, exhibit a difference of strength of 14 to 22.* 
 
 The strength of granite depends, first, upon the 
 proportion of its constituent parts ; and, secondly, 
 upon the chemical state of those particles. The 
 constituents of Herm granite (sienitic) are felspar, 
 quartz, and hornblende, with a very small quantity 
 of black mica ; the whole being in a highly crystal- 
 line state. The Brittany granites generally contain 
 a considerable quantity of mica, which, from its fra- 
 gile nature, or want of cohesion, deteriorates the 
 quality of the stone; the Guernsey granites are tole- 
 rably free from this substance. A black granite, 
 much used near London for mending the roads, is 
 almost wholly composed of black masses of mica ; 
 in the sienite of Malvern, red felspar predominates, 
 and in the Dublin granite, white opaque felspar, 
 intermixed with a moderate quantity of black mica, 
 are the chief constituents of the mass. 
 
 * For a practical application of these varieties, the student is 
 referred to Waterloo Bridge ; the ballustrades are formed out of the 
 Aberdeen granite.
 
 XV11 
 
 These varied proportions and qualities of the 
 compounds create a very sensible difference in the 
 quality of the stone ; thus, in the sienitic granite of 
 Herm the absence of micaceous particles gives place 
 to hornblende, which is hard and crystallized in small 
 prisms (Lukis, Trans. Inst. C.E.), thereby increas- 
 ing the specific gravity of the stone. In the British 
 granites, the felspar is mostly opaque ; in the Herm 
 granite it is crystallized and partly transparent ; in 
 the Dublin granite, the opaque felspar is the most 
 prevalent ; and in some of the English varieties 
 exists in large cubical masses : again, in most British 
 granites the quartz is comparatively small in quan- 
 tity, but in the harder and more durable varieties, 
 both quartz and felspar are abundant, and trans- 
 parent or crystallized. 
 
 With these facts before us, it isjiot difficult to 
 arrive at just conclusions respecting the quality of 
 this material ; but in the event of any doubts arising 
 in the mind of the reader, we refer him to the first 
 volume of the Transactions of the Institution of Civil 
 Engineers, in which will be found a paper describ- 
 ing a series of important experiments on various 
 kinds of granite, made under the direction of the 
 late Mr. Bramah. 
 
 Among these experiments, we find that 2 
 cubes of Herm granite (4x4x4) weighing 6 Ibs. 
 6 oz. were fractured with a mean pressure of 
 4.77 tons upon the superficial inch, and wefe 
 crushed with a mean pressure of 6.64 tons per inch 
 b
 
 superficial, while the remaining fpecimens, consisting 
 of Aberdeen (blue), Haytor, Dartmoor, Peterhead 
 (red), and Peterhead (blue gray), declined gradually 
 in strength, the two cubes of the last specimens 
 weighing 51bs. 3^ oz., and 5 Ibs. 4 oz., being frac- 
 tured with a mean pressure of 2.86 tons upon the 
 inch superficial, and crushed with a force of 4.36 
 tons upon the inch. For the locality of the prin- 
 cipal English granites, the reader is referred to the 
 account of the counties of Cornwall and Devon. 
 
 The constituents of mica schist and gneiss are 
 analogous to those of granite, but arranged in 
 laminae; the former is of a slaty structure, composed 
 of continuous sheets of mica, with grains of quartz : 
 quartz rock and primary limestones are also inter- 
 posed among the beds of mica schist (Phillips). 
 Gneiss accompanies mica schist; its composition is 
 very similar to granite, but the mica is disposed in 
 patches, and occasionally much contorted, instead 
 of being disseminated throughout the mass as in 
 common granite. 
 
 These rocks are not generally suitable for 
 building materials, and being sparingly exhibited 
 in England, do not demand the attention of the en- 
 gineer ; we may, however, remark, that an assem- 
 blage of grains consisting of quartz, schist, felspar, 
 and particles of mica, &c., agglutinated with a va- 
 riable cement, form the "psammites" of Mr. Vicat. 
 fhose, he observes (p. 46, Treatise on Cements), 
 are the most important which are slaty, of a yellow,
 
 XIX 
 
 red, or brown colour, fine grained, unctuous to the 
 touch, producing a clayey paste with water. These 
 belong to the primitive schistose formations, and 
 cannot exist except in situ, being found in " beds or 
 veins, forming part of the schist of which they are 
 merely a decomposition." 
 
 In the composition of mortar, the schistose 
 sands or "psammites" are feebly energetic,* namely, 
 causing the mortar to set from the tenth to the 
 twentieth day, and that acquires the hardness of dry 
 soap after a year's immersion. Acid will act upon 
 the clay of these sands, causing it to yield after 
 maceration a portion o^iron, and from -^ to -f- of its 
 alumina. 
 
 The clay-slate and graywacke system exhibits 
 a series of fine and coarse grained argillaceous, in- 
 durated, fissile rocks and sand, with conglomerates 
 and limestone bands ; the subdivisions consisting 
 of dark flag-like slates, limestone, green slate frag- 
 mentary rocks, and dark soft slate. The tran- 
 sition limestone of Plymouth is associated with 
 the graywacke series ; it is a variegated limestone, 
 having a splintery fracture, but, like most calcareous 
 rocks, is not proof against the action of water and 
 marine animals (vide the Plymouth breakwater) ; 
 graywacke, basaltic trap, &c., are not to be recom- 
 mended for engineering works, where other mate- 
 rials may be readily obtained. 
 
 * Pure sands are inert substances. (See Vicat on Cements, by 
 Smith.)
 
 XX 
 
 Silurian rocks* (Murchison). The Ludlow 
 rocks consist of beds of sandstone shale and lime- 
 stone, with the following subdivisions : 1. Lami- 
 nated sandstone (Upper Ludlow rock). 2. Lime- 
 stone ( A.ymestry limestone). 3. Sand shale and 
 clay, with concretions of earthy limestone (Lower 
 Ludlow rock). 
 
 The Wenlock and Dudley rocks consist of 
 strata of limestone and shale, with the following 
 subdivisions. 1. A mass of highly concretionary 
 gray and blue sub-crystalline limestone (Wenlock 
 arid Dudley rocks). 2. Argillaceous shale, liver 
 and dark gray coloured, Barely micaceous, with 
 nodules of earthy limestone (Wenlock and Dudley 
 shale). 
 
 Horderly and Mayhill rocks. Conglomerates, 
 sandstones and limestones. Subdivisions. 1 . Thin 
 bedded impure shelly, limestone ; and finely lami- 
 nated, slightly micaceous greenish sandstone. 2. 
 Thickly bedded, red, purple, green, and white fre- 
 stones ; congiomoritic quartzose grits, sandy and 
 gritty limestones. 
 
 Builth and Llandeilo rocks. Beds of dark co- 
 loured flags, mostly calcareous, with some sand- 
 stone and schist. We now proceed to complete the 
 enumeration of the Welsh counties, and the index to 
 the foregoing classes of rocks and strata. 
 
 * This classification is from J. and C. Walker's elaborate and 
 beautiful "Geological and Railway Map of England," &c., recently 
 published.
 
 Denbigh. 
 
 The county of Denbigh contains, 1. Clay- 
 slate. 2. Graywacke. 3. Silurian rocks ; and bor- 
 ders on the carboniferous limestone. 
 
 Flint. 
 
 The county of Flint contains, 1. Coal. 2. Mill- 
 stone grit. 3. New red sandstone. 4. Silurian 
 rocks. 5. Trap. And, 6. Carboniferous limestone 
 and lias, near the detached part of the county. 
 
 The parish of Whiteford in this county, contains 
 a stratum of valuable bituminous limestone, which 
 furnishes a lime of great strength, and when in a 
 state of hydrate, will rapidly harden under water. 
 (Seep. 114). 
 
 Merioneth. 
 
 The county of Merioneth contains, chiefly, 
 graywacke. 
 
 Montgomery. 
 
 The county of Montgomery contains, 1. Coal 
 2. Trap. 3. Clay -slate and graywacke. 4. Silu- 
 rian rocks. And, 5. Old red sandstone. 
 
 Cardigan. 
 
 The county of Cardigan contains, 1. Coal. 2. 
 Millstone grit. 3. Silurian rocks. And, 4. New 
 red sandstone.
 
 XX11 
 
 Radnor. 
 
 The county of Radnor contains, 1. Trap. 2. 
 Clay-slate. 3. Silurian rocks. 4. Graywacke. And, 
 6. Old red sandstone. 
 
 Brecknockshire. 
 
 Brecknockshire contains, 1. Old red sand- 
 stone. 2. Silurian rocks. 3. Clay-slate and gray- 
 wacke. 4. Carboniferous limestone; and skirts the 
 coal of Glamorganshire. 
 
 Caermarthen. 
 
 The county of Caermarthen contains, 1. Si- 
 lurian rocks. 2. Clay-slate and graywacke. 3. 
 Coal. 4. Old red sandstone. And, 5. Carbonifer- 
 ous limestone. 
 
 Pembroke. 
 
 The county of Pembroke contains, 1. Clay- 
 slate and graywacke. 2. Coal. 3. Trap. And, 4. 
 Old red sandstone. 
 
 Glamorgan. 
 
 The county of Glamorgan contains, 1. Coal. 
 2. Millstone grit. 3. Old red sandstone. And, 4. 
 Lias. 
 
 The lias beds of this county furnish the material 
 from which the celebrated Aberthaw lime is made.
 
 XX111 
 
 MonmoutJL 
 
 The county of Monmouth contains, 1. Silurian 
 rocks. 2. Coal. 3. Old and new red sandstone. 
 And, 4. Carboniferous limestone. 
 
 For local purposes, the geological formations of 
 the Welsh counties may supply abundant materials 
 for engineering operation*; but the peculiar compo- 
 sition of most of these deposits renders them com- 
 paratively useless in any other district, particularly 
 when it is remembered that great facilities are now 
 afforded to the engineer in obtaining the more valu- 
 able and workable materials of the calcareous and 
 carboniferous series. 
 
 Cheshire. 
 
 The county of Cheshire is mostly occupied by 
 the new red sandstone formation. The sandstones 
 of this formation are generally of a red colour, and 
 not micaceous (Phillips). The subdivisions consist 
 of marl, red sandstone, and conglomerates (Burr). 
 The sandstones consist of a great diversity of colours, 
 and, from this circumstance, the entire formation has 
 received the name of " variegated sandstone/' " bun- 
 ter sandstein," (Werner); and " red rock," "red 
 ground," and " red marl," of other geologists. The 
 new red sandstone is thus described by Mr. Aikin, 
 in a paper on " The Wrekin and the Great Coal 
 Field of Shropshire" (Geol. Trans., vol. i. p. 192): 
 " This rock consists, for the most part, of rather fine 
 grains of quartz, with a few spangles of mica, ce-
 
 XXIV 
 
 mented by clay ancjpoxyde of iron. Its colour is 
 generally brownish red, and it has but little cohe- 
 sion, on which account, large tracts of loose deep 
 sand are found in many parts of it. Sometimes it 
 occurs nearly of a cream colour, and is then suffi- 
 ciently hard to form an excellent building stone. It 
 does not effervesce with ^cids, and, to the best of 
 my knowledge, never contains shells or other or- 
 ganic remains." 
 
 The arenaceous deposits of the new red sand- 
 stone system exhibit; considerable diversity of cha- 
 racter ; thus, at Kirkby-Stephen, the deposit con- 
 tains a brecciated rock, with limestone fragments ; 
 at Nottingham, a pebbly conglomerate ; at Runcorn, 
 one with few pebbles ; at Penrith Beacon, a coarse 
 red grit ; a fine kind, suitable for building, at Meri- 
 den-hill, near Coventry, and colour, white or green 
 (Warwickshire).* Although the new red sandstone 
 is not generally applicable for building, yet, in some 
 districts, a very suitable and durable kind may be 
 obtained. The principal quarries in Cheshire are at 
 Runcorn, Manley, Peckforton, and adjacent places. 
 
 Buildings constructed with this material may 
 be seen on the Liverpool and Manchester Railway ; 
 and a fine section of the rock, showing its peculiar 
 vertical fissures, may be examined with advantage 
 at Olive Mount, the deep rocky cutting near the 
 entrance of the Liverpool Tunnel. Stockport church, 
 Cheshire (Basevi, architect), is mostly built with 
 
 * Philips's "Treatise on Geology," p. 184.
 
 XXV 
 
 Runcorn stone ; and the bridge over the Dee, at 
 Chester, by Harrison, is faced with a light-coloured 
 stone from the quarries of Manley and Peckforten. 
 The two courses of arch stones in the river abut- 
 ments of Chester bridge are of Scotch granite 
 (Craignair) ; the key course, with one on each side, 
 and the quoins all through, are of Anglesea and 
 similar limestone, from Wagbur quarries, at Burton, 
 in Kendale. The tower of Kenton, in Devonshire, 
 is also constructed with a durable stone belonging 
 to the red sandstone series.* 1 The unsightly and 
 rusty appearance oi' some of the worst varieties of 
 this stone, may be seen in many old buildings in the 
 ancient city of Chester, including the cathedral. 
 
 The student should be informed that, in this 
 country, the new red sandstone is always associated 
 with the rock salt and gypseous deposits, hence the 
 name, " saliferous." The limestones associated with 
 the new red sandstone exhibit considerable variety ; 
 their colours are white, gray, smoky, yellow, and 
 red (Phillips), often containing much magnesia, 
 hence their name, " magnesian limestones." The 
 texture of these calcareous beds are oolitic, cellular, 
 granular, nc-wdery, and, in Nottinghamshire, granu- 
 lar and crystallized. 
 
 Derby. 
 
 Derbyshire contains, 1. Coal, consisting of al- 
 ternations of coal, sandstones, shales, and ironstone 
 
 * Conybeare.
 
 XXVI 
 
 beds. 2. Millstone grit, namely, quartzose grits 
 with shales, coal, ironstone, &c. 3. Carboniferous 
 or mountain limestone, namely, limestone either in 
 one mass or divided by shales, gritstones, ironstones, 
 and coal. And, 4. Trap.* A description of the 
 carboniferous limestone will be found in Chapter 4 
 of this Treatise. 
 
 Mr. Party, in his " Agricultural Survey of 
 Derbyshire," enumerates forty-six limestone quar- 
 ries in this county, and sixty-three lime kilns, from 
 whence great quantities are conveyed and sold in 
 this and some of the neighbouujpg counties. The 
 largest quarries are at Ashover, Buxton, Crich, and 
 Calver, near Barslow. A considerable quantity is 
 sent from Calver into Yorkshire, and from Buxton 
 into Cheshire and Staffordshire. The marble quar- 
 ries are nineteen in number, and are situated near 
 Bakewell and Matlock. The number of stone quar- 
 ries are one hundred and thirty-eight, in some of 
 which an excellent building stone may be obtained. 
 The best quarries for this kind of stone are situated 
 in the parish of Wingerworth. Millstone grit is 
 obtained from nineteen quarries ; and other finer 
 kinds of sandstone from thirteen quarries.^ The best 
 quarries for the latter are at Codnor Park and 
 Woodthorpe.f The sandstones of the carboniferous 
 series are amply described under the head " Nor- 
 thumberland." 
 
 * The magnesian limestone is adjacent to the county. 
 t Farey's "Survey of Derbyshire."
 
 XXV11 
 
 Nottingham. 
 
 The county of Nottingham contains, 1. New 
 red sandstone. 2. Magnesian limestone ; with coal 
 on the Derby side and lias on the Lincoln side. 
 
 The prevailing deposit in this county is the 
 new red sandstone, already described. Limestone is 
 burnt in various parts of the county, both from 
 the lias and magnesian deposits ; from the former, 
 on Beacon-hill, near Newark. The quarries for the 
 best building and paving stone are situated at 
 Mansfield, Maplebeck, Beacon-hill, and at Linby, a 
 few miles to the south-west of Mansfield.* The 
 new red sandstone of this county is mostly of a loose 
 and friable texture. 
 
 Lincolnshire. 
 
 The county of Lincoln contains, 1. Chalk. 2. 
 Green sand. 3. Upper, middle, and lower oolite. 
 4. Lias ; with much marsh or fenny land. The 
 materials peculiar to these formations will be found 
 noticed under the several counties where the forma- 
 tions are more largely developed, namely, Surrey, 
 Sussex, Kent, Northamptonshire, &c. It may be 
 observed, however, that the lower chalk beds have 
 a ferruginous or red stain.t 
 
 The strata immediately under the Lincolnshire 
 
 * "Agricultural Survey." 
 
 t A similar variety exists in the East Riding of Yorkshire.
 
 chalk is described, by Mr. Bogg,* as consisting, 
 first, of a coarse, ferruginous, pebbly, quartzose sand. 
 Secondly, a stratum of oolitic limestone and calca- 
 reous clay, in nearly equal proportions. In certain 
 parts of this bed, the clay divides the seams of stone 
 into regular strata. The next stratum is that of a 
 quartzose sandstone of different shades of colour. 
 Notwithstanding these indications of strata capable 
 of furnishing building materials, Lincolnshire does 
 not possess any of sufficient importance to merit the 
 attention of the engineer. 
 
 The soil of the Louth marshes consists of un- 
 stratified clay and sand, under which is the chalk ; 
 but a considerable denudation has been effected in 
 Lincolnshire, whereby the upper oolitic beds have 
 been removed. In consequence of the vast extent 
 of fenny land in this county, the foundations of 
 many of the oldest buildings rest upon piles; pro- 
 bably the earliest English examples of this mode of 
 constructing foundations. 
 
 Rutland. 
 
 The county of Rutland contains, 1. Lower 
 oolite. 2. Lias. 
 
 This county does not supply any building 
 materials worth the particular attention of the en- 
 gineer ; but its situation with respect to other coun- 
 ties, furnishing an ample supply of stone, lime, and 
 brick, is such, that no difficulty is likely to arise 
 
 * Mr. Bogg, " On the Lincolnshire Wolds." Geol. Trans., vol. iii. p. 394.
 
 from the want of materials in the immediate locality. 
 The ferruginous sandy beds of the lower oolitic 
 series supply calcareo-siliceous materials, which were 
 formerly much employed in some of the adjoining 
 counties. The materials derived from these beds 
 are very inferior and unsightly for architectural 
 purposes.* The sandstone series is generally sepa- 
 rated from the great oolite by a thick clay (Cony- 
 beare). 
 
 Leicester. 
 
 The county of Leicester contains, 1. Lias. 2. 
 New red sandstone. And, 3. Sienitic granite, trap, 
 and graywacke of Mount Sorrel. Roofing slate is 
 quarried at Swithland, east of Charnwood forest. 
 The principal limestone quarries are at Bredon, 
 Cloud-hill, and Barrow-upon-Soar. Freestone, of 
 the new red sandstone species, is found in most 
 parts of the county, also brick earth. Sienitic 
 granite is quarried at Mount Sorrel ; much of it is 
 used for metalling the roads. 
 
 Stafford. 
 
 The county of Stafford chiefly contains new 
 red sandstone and coal. The quarries situated in 
 this cc^nty are very numerous. Excellent free- 
 stone, mostly derived from arenaceous deposits, is 
 quarried largely. There are several quarries at 
 
 * The old buildings in and about Northampton, Ban bury, &c., are 
 built with stone procured from the strata alluded to.
 
 xx 
 
 Gornal, Bilston, Sedgley, Tixall, Wrottesley, Bre- 
 wood Park, Pendeford, and the Rowley-hills. The 
 stone from the latter place is much employed for 
 paving ; it is called Rowley rag-stone, and is found 
 in heaps similar to the " stone shatter," or Kentish 
 rag. In the neighbourhood of Tamworth there are 
 several quarries, within a mile and a half of each 
 other, from which is raised a durable building stone, 
 provincially termed " whinstone." The railway 
 viaduct now building at one end of Tamworth, is 
 being constructed with this stone. The viaduct 
 crosses the Tame river and two roads, and rises to 
 an elevation of twenty feet above the town, and 
 consists of eighteen square apertures of thirty feet 
 span each, and a skew arch of sixty feet span. The 
 stone is a grit of fine texture, and brownish colour. 
 The quarries for this stone are at Dost-hill and 
 Stokes quarry, Amington. Limestone abounds in 
 this county. Extensive lime works are situated at 
 Caldon Low and near the Weaver-hills. Brick 
 earth of good quality is excavated in many places. 
 The limestone marble peculiar to this county is 
 valuable, but not of sufficient importance (to the 
 engineer, at least) to require further notice. 
 
 Salop. 
 
 Shropshire contains, 1. Coal and Trap. 2. 
 New red sandstone. 3. Lias. 4. Silurian rocks. 
 5. Old red sandstone. 6. Magnesian limestone. And, 
 7. Carboniferous limestone.
 
 XXXI 
 
 Shropshire presents abundance of materials to 
 the notice of the engineer, but the limits of this 
 Register will only permit the enumeration of the 
 principal quarries. 
 
 In addition to the limestone near Oswestry and 
 Chirk, a long range of stony strata (silurian) exr 
 tends from Colebrook Dale, by Wenlock, to Lud- 
 low. The most extensive lime works are at Lille- 
 shall. Limestone quarries are worked at Steiraway ; 
 and lime and stone may be obtained in the Glee- 
 hills, and, to a limited extent, in the south-western 
 districts. At the eastern extremity of the Wrekin, 
 and at some other lime works, a red lime of the 
 hydraulic kind is made. The best lime of this 
 county is made from the limestone of the lias beds. 
 The principal sandstone quarries are at Grimshill 
 and its neighbourhood, near Bridgenorth, Orton 
 Bank, parish of Bettws (stone slate), on the south- 
 western verge of the county ; Coondon hill (flag- 
 ging), Swinney quarries, near Oswestry ; Bowden 
 quarry, in the hundred of Mun'slow and Soudley 
 (flagging), in the parish of Eaton and franchise of 
 Wenlock. The principal hills are, 1. Lawley-hill, 
 a kind of granite and loadstone. 2. Caer Caradoc- 
 hill, schistus. And, 3. The Wrekin, chiefly com- 
 posed of reddish chert and quartz. The Oswestry 
 hills are a coarse-grained sandstone* 
 
 * Lewis's Top. Die. The student is also referred to an elaborate 
 paper " On the Wrekin and on the great Coal Fields of Shropshire," 
 by Arthur Aikin, Esq. Geol. Trans., vol. i. p. 191.
 
 XXX11 
 
 Hereford. 
 
 Herefordshire contains, 1. Old red sandstone. 
 And, 2. Silurian rocks. 
 
 The greater portion of this county is occupied 
 by the old red sandstone formation ; this deposit, 
 therefore, will now demand our attention. The 
 old red sandstone consists of "beds of sandstones, 
 conglomerates, clay, and concretionary limestone of 
 various colours, but mostly red ;" the subdivisions 
 consist of quartzose conglomerates and sandstones, 
 coloured marls, concretionary limestones, and flag- 
 stone series (Walker map). This sandstone is 
 generally of a dirty iron-red, or dark brown, occa- 
 sionally passing into gray ; it rests upon graywacke 
 rock, into which it passes insensibly ; it is mica- 
 ceous, coarse-grained, and apparently constituted of 
 abraded quartz, felspar, and mica ; it alternates with 
 argillaceous beds. Subordinate to it are some un- 
 important beds of limestone. In general appear- 
 ance it approaches to the sandstones of the millstone 
 grit series (Conybeare, " Geology of England and 
 Wales," p. 362). The limestone beds below the 
 surface near Snodhill castle, were originally worked 
 for the kind of marble they afford ; the marble (red 
 and white) is said to have been in much estimation 
 during part of the seventeenth century. In addition 
 to the quarries of red sandstone* distributed through- 
 
 * It is observed (Brande's Journal, vol. iii.p.381), that "the fitness 
 of the different species of sandstone for the purpose of building, may, 
 in a great measure, be judged of by immersing the specimens in water,
 
 XXX111 
 
 out the county, an inferior kind, called " dunstone," 
 is also quarried. Much of the limestone of this 
 
 each being previously weighed, and all of one size, the excellence of 
 the stone will be inversely to the quantity of water absorbed." A 
 perfect analysis is, however, for many reasons, to be preferred. The 
 most perfect one that has fallen under the notice of the author, is accu- 
 rately described in No. 13 of the " Civil Engineer and Architect's 
 Journal." It is a translation from the German of Dr. Buehner, profes- 
 sor in the University of Vienna. The following is the method, extracted 
 from the " Journal :" 
 
 " A piece of gray sandstone weighing 30f ounces, was laid in distilled 
 water for twenty-four hours ; and on being taken out and weighed, it 
 was found to have increased six grains, hardly two per cent., thus 
 affording a good proof of its closeness of formation, and small power of 
 absorption. The water in which the stone had been laid was evaporated 
 to an ounce, and a yellowish residuum was obtained, which, on being 
 subjected to reagents, was found to consist of sulphate of lime and 
 sulphate of soda, mixed with organic matter. A piece of the sandstone 
 was pulverized, and 100 grains of it treated with muriatic acid, and a 
 partial dissolution effected by the development of carbonic acid gas. 
 The remaining acid having been renewed by evaporation, the residuum 
 of quartz sand was washed and cleaned with warm water, and found to 
 weigh 57 grains. The muriatic residuum was subjected to nitrate of 
 ammonia, whereby alumina was produced, with a portion of oxide of 
 iron. It weighed, on careful trial, 3J grains. The solution filtered 
 from the aluminous precipitate was treated with oxalic ammonia, to 
 produce deposition of the lime, which was exposed to the fire, to 
 convert the oxalate of lime into carbonic acid gas, and by which 24 
 grains of carbonate of lime was produced. The fluid filtered from this 
 was acted upon by phosphate of natron, and a precipitate of phosphate 
 of ammonia and magnesia appeared, which, by heat, was reduced to 
 neutral phosphate of magnesia, which was calculated as 13 per cent 
 of carbonate of magnesia. The composition of the stone was, 
 consequently, 
 
 Quartz 57 
 
 Alumina 3.5 
 
 Carbonate of lime 24 
 
 Ditto magnesia 13 
 
 Loss 2.5 
 
 100
 
 XXXIV 
 
 county being argillaceous, burns to lime of good 
 quality. 
 
 Worcester. 
 
 The county of Worcester contains, 1. Lias. 2. 
 New red sandstone. And, 3. Sienitic granite (Mal- 
 vern hills). 
 
 In Worcestershire, Bath stone and lias lime is 
 extensively used ; but the building materials in the 
 immediate locality consist of sandstone of the new 
 red formation, and limestone of the lias and Silurian 
 beds. Lime and limestone is procured at South 
 Littleton, Witly, and Huddington. Quarries of cal- 
 careous flagstone (lias) are worked in the vale of 
 Evesham, in the parishes of Badsey, Three Little- 
 tons, and Prior's Cleeve. Lias limestone is also 
 quarried in the vicinity of Stoke Prior. The Mal- 
 vern sienite is occasionally used for metalling the 
 roads. The bricks manufactured in the county are 
 firm, and of a bright red colour. 
 
 Warwick. 
 
 The county of Warwick contains, 1. Coal. 2. 
 New red sandstone. 3. Lower oolite. And, 4. Lias. 
 
 " From these results it was proved that the sandstone of Waakirchen 
 was a good building material, and fully capable of resisting the effects of 
 air and water, as its component parts were not liable to decomposition, and 
 its texture did not admit the introduction of their mechanical force. It is 
 evident that it is only by such trials that the true qualities of materials are 
 to be ascertained, as mere mechanical action, or a trial of temperature, 
 affords no criterion of the chemical constitution by which injuries of 
 weather are caused."
 
 XXXV 
 
 Freestone quarries of the new red sandstone and 
 lias formations are to be found near Warwick, Lea- 
 mington, Kenilworth, Coventry, &c. Limestone 
 quarries are also situated near Bearley, Grafton 
 Court, Stretton, Princethorpe, Upton, Harbury, 
 Wilncote, Bidford, Newbold-on-Avon, and on the 
 borders of Oxfordshire and Leicestershire. Blue 
 flagstone (lias) is quarried at Bidford and Wilncote. 
 A ferruginous sandstone is to be met with at 
 Oldbury and Merevale. 
 
 Other kinds of stone are used in this county, 
 namely, Gornal stone (prices, 1838), Is. 4Jd. per 
 cube foot ; Wharton stone, Is. 3d. ; blue stone, for 
 paving, lOd. to Is. ; Bath stone, 2s. 9d. ; Painswick 
 stone, 3s. Bricks (red), 23s. to 26s. per thousand, 
 according to distance. 
 
 Northampton. 
 
 The county of Northampton contains, 1 . Lias. 
 2. Lower oolite. Building stone is raised at Brack- 
 ley Kingsthorpe, near Northampton. Stone slate, 
 or thin flagging, is dug at Collyweston, near Stam- 
 ford. The oolite called " Ketton stone " is found 
 near Stamford, and quarried there. The lime of 
 this county is mostly of the lias kind, and is quar- 
 ried on the western side. 
 
 The older buildings of the county have been 
 
 constructed with the rusty sandstone from the upper 
 
 beds of the lower oolitic series. The bricks are of 
 
 two kinds, red and light-coloured; many of the 
 
 c2
 
 XXXV111 
 
 ings at Cambridge is from the Whitby, Portland, 
 Pafnswick, and Ketton quarries. 
 
 Norfolk. 
 
 The county of Norfolk contains, 1. Crag 
 and diluvian. 2. Chalk. 3. Green sand and upper 
 oolite. 
 
 In this county the materials, with the excep- 
 tion of brick, must be obtained from the adjoining 
 counties, or brought coastwise from the principal 
 stone quarries of England. 
 
 The most ancient buildings in the counties of 
 Suffolk and Norfolk, are constructed with flint or 
 boulder walls, and limestone (oolitic) or brick 
 quoins. 
 
 Suffolk. 
 
 The county of Suffolk contains, 1. Crag. 2. 
 London and plastic clay. 3. Chalk. And, 4. Green 
 sand. 
 
 With respect to building stone and brick, the 
 observations above will apply also to this county ; 
 but the local deposit called " crag " requires a 
 passing notice. 
 
 The extent of this marine deposit is not yet 
 ascertained (Conybeare). The districts with which 
 we are best acquainted are the eastern parts of Nor- 
 folk and Suffolk, extending to Walton Naze, in 
 Essex. This deposit consists of an heterogenous
 
 XXXIX 
 
 mass of matter, namely, sand, gravel, blue and 
 brown marl, and broken shells. In some places it 
 assumes the character of a soft, stratified rock, com- 
 posed almost entirely of corals, sponges, and echini ; 
 in other parts it consists in alternations of sand and 
 shingle, destitute of organic remains, and more than 
 two hundred feet in thickness, as in the Suffolk 
 cliffs, between Dunwich and Yarmouth (Lyell). 
 The more consolidated portions are occasionally 
 employed for ordinary building purposes, and quar- 
 ries of it are worked at Southwold, and on the 
 southern bank of the river Orwell, in Suffolk 
 (Conybeare). 
 
 The bricks manufactured in Suffolk are from 
 a light clayey loam ; they burn to a very light 
 colour, and are much used for facings. 
 
 Essex. 
 
 The county of Essex contains, 1. London clay. 
 And, 2. Plastic clay. 
 
 The materials supplied by this county chiefly 
 consist of bricks of good quality, and septaria, or 
 English cement stone, procured from the Harwich 
 cliffs. The peculiar nature of the London and 
 plastic clays, and the composition of septaria will 
 be found duly noticed in the 1st and 5th chapters 
 of the " Treatise." 
 
 Much of the lime used in this county is pro- 
 cured from Purfleet and Grays ; it is, also, occasion-
 
 ally brought from Dorking, Greenhithe, &c., on the 
 other side of the river Thames. The London clay 
 constitutes a very large part of the soil of Suffolk, 
 nearly the whole of Essex, including Hainhault and 
 Epping forests, quite to the sea, the whole of Mid- 
 dlesex, and portions of Berkshire, Surrey, and Kent 
 (Phillips). The London clay is often found imme- 
 diately under the alluvial soil, but is more frequently 
 covered with a diluvial coating of gravel, of consi- 
 derable thickness. 
 
 Hertford. 
 
 Hertfordshire contains, I. Plastic clay. And, 2. 
 Chalk. 
 
 The soils of Hertfordshire are chiefly gravel, 
 clay, and chalk. The gravel tract lies in the 
 south eastern part of the county, and contains 
 17,280 acres. The chalk district, extending along 
 the whole border of the northern part of the county, 
 contains 46,720 acres. The clay districts are 
 situated, one on the southern, and the other (the 
 largest) on the eastern side of the county. The 
 materials of this county are bricks of good quality 
 and chalk lime. 
 
 Bedford. 
 
 Bedfordshire contains, the Upper, middle, and 
 lower oolitic series, bounded by green sand.
 
 xli 
 
 With the exception of some very inferior sand- 
 stone belonging to the upper beds of the oolitic 
 series, the strata of Bedfordshire does not supply 
 stone fit for the purposes of masonry. Its contiguity 
 to the counties of Buckinghamshire, Oxfordshire, 
 and Northamptonshire will, however, enable the 
 architect or engineer to draw his supplies with 
 facility, should the materials peculiar to these coun- 
 ties be considered suitable for the intended works. 
 Lime and bricks may be procured on the borders of 
 Hertfordshire. 
 
 Buckingham, 
 
 Buckinghamshire contains, 1. Plastic clay. 
 2. Chalk. 3. Green sand. 4. Upper, middle, and 
 lower ooolite. 
 
 The first important development of the oolitic 
 series of rocks is to be found in this county, 
 and from which the whole of the series may be 
 successively traced, namely, through Oxfordshire, 
 Berkshire, Wiltshire, Dorset, Somersetshire, Glou- 
 cestershire, &c. 
 
 The Aylesbury or Portland limestone first 
 makes its appearance in that part of Buckingham- 
 shire which lies west of the Grand Junction Canal. 
 It forms the central and lower regions of a chain of 
 hills capped by the Iron sand : at Brill Hill, the 
 Portland beds rise nearly to the summit, having at
 
 xlii 
 
 that spot only a slight covering of iron sand (Cony- 
 beare). The Aylesbury limestone quarries contain 
 a series of beds of unequal quality, namely, a fine- 
 grained white oolite, a loose granular limestone, of 
 earthy aspect, and of various shades of yellowish 
 gray ; and, more rarely, a compact cretaceous lime- 
 stone, having a conchoidal fracture (Conybeare). 
 The more oolitic variety of the upper series (Port- 
 land) and the argillaceous variety above the Portland 
 (Purbeck) is described in the account of the Port- 
 land and Purbeck quarries. 
 
 In addition to the limestone quarries already 
 mentioned, marble was formerly quarried in this 
 county, but. it was found incapable of retaining a 
 good polish, or withstanding the effects of the 
 atmosphere ; its use has, therefore, been discontinued. 
 (Lewis, Top. Die.) 
 
 Oxford. 
 
 Oxfordshire contains, 1. Green sand. 2. Chalk. 
 3. Upper, middle, and lower oolite, and is adjacent to 
 the lias formation. 
 
 The oolitic system is more extensively deve- 
 loped in this than in the former county, but the 
 materials drawn from the middle or coral rag divi- 
 sion of the oolitic series (the one under notice), are 
 of a very inferior description, being highly objec- 
 tionable for the finer purposes of masonry, and the
 
 xliii 
 
 different beds (near Oxford and in Wiltshire) are 
 exhibited in the following progression, commencing 
 from the top. 1. A calcareous freestone of tolerably 
 close texture, more or less oolitic, but full of commi- 
 nuted shells, and passing into beds of a large oviform 
 grain, forming the "pisolite" of Mr. Smith. The 
 colour of these beds is of a yellowish white, becoming 
 palest in the most oolitic, and passing occasionally 
 into shades of light gray. This bed affords a tole- 
 rable material for building, but is objectionable on 
 account of its being traversed by lines of division 
 oblique to the plane of stratification (Conybeare). 
 
 Much of this stone has been used in the colle- 
 giate and ecclesiastical buildings of Oxford, where 
 the peculiar defect of its stratification may be ob- 
 served in the scaling or peeling off of the outer 
 surface, after exposure to the weather : this stone 
 contains a considerable quantity of sand. The coral 
 rag immediately follows the bed of stone already 
 described, and consists of a loose rubbly limestone, 
 made up of several species of aggregated and 
 branching madrepores; it is used for lime and 
 mending the roads (Conybeare). 
 
 The beds of coral rag form an elevated platform, 
 rising on the south-west of Otmoor, and supports 
 the still higher ridge (Portland beds and iron sand) 
 which constitutes the summit of Shotover Hill. The 
 quarries are situated on this platform, and are very 
 numerous ; the principal quarries are those of Head- 
 ing-ton, two miles east of Oxford (Conybeare).
 
 xliv 
 
 The several clays * which divide the oolitic 
 series, require no further observation, than that they 
 afford to the engineer or builder an opportunity of 
 procuring a supply of bricks throughout a very 
 extensive district in which limestone is abundant. 
 
 Gloucester. 
 
 Gloucestershire contains, 1. Lower oolite. 2. 
 Lias. 3. New red sandstone. 4. Mountain lime- 
 stone. 5. Old red sandstone. And, 6. Coal. 
 
 The upper beds of the lower oolitic series 
 furnish a considerable quantity of lime and lime- 
 stone, which is much used in the Cotswold district. 
 The principal upper beds of this series (in Glou- 
 cestershire) are the corn-brash or corn-grit, forest 
 marble, Stonesfield slate, &c. The Corn-brash is a 
 loose rubbly limestone, of a gray or bluish colour, 
 especially near the superincumbent clay, but on the 
 exterior brown and earthy ; it rises in flattish masses, 
 rarely more than six inches thick. It is not fit for 
 any purpose, excepting for lime and the repair of 
 the highways ; but at Malmesbury, where it is thick 
 and solid, it is much quarried for building. It 
 may readily be discovered by the red soil which 
 constantly attends itf (Conybeare). 
 
 * The Oxford or clunch clay is a dark blue adhesive clay, containing 
 septaria : it underlies the limestone already described, separating the infe- 
 rior or lower oolite from the former. 
 
 f We may here observe, that beds of forest marble are worked near 
 Woodford (Bucks), and at Marsh Gibbon, Ambrosden, Merton, and
 
 xlv 
 
 The greatest thickness of the lower oolitic beds,* 
 is exhibited in the continuous chain of hills, known 
 as the Cotswold hills. Many quarries are worked 
 on these hills, and others are situated near Bad- 
 mington Park. In Gloucestershire, the great oolite 
 always crowns the brow of the escarpment of the 
 hills. The loftiest point of these hills is Cleeve 
 hill, near Cheltenham (Conybeare). 
 
 The limestone of the Forest of Dean, Lang- 
 hope, and adjacent places is quarried for building, 
 but the lime is inferior to that made from the vast 
 limestone beds of the southern extremity of the 
 county. (See Chapter iv. of the " Treatise.") 
 
 Freestone is raised from the Cotswold quarries, 
 and paving stone is raised at Frampton, Cotterell, 
 Winterbourne, Iron Acton, Mangotsfield, Stapleton, 
 and in the Forest of Dean; the latter place sup- 
 plies millstone, and other grits of excellent quality. 
 Stone slate may be procured on the Cotswold s. 
 
 Wiltshire. 
 
 Wiltshire contains, 1. A small portion of plas- 
 
 Bletchingdon (Oxon). From the latter quarries, the stone for the pillars in 
 the inner quadrangle of St. John's college, Oxford, were procured (Cony- 
 beare). The calcareous slate quarries of Stonesfield, near Woodstock, are 
 situated in the valley immediately on the south of Stonesfield village. The 
 forest marble is composed of little else but a mass of shells (Ibid.) 
 
 * The limestone of the Cotswold district, is arranged in beds, from two 
 to ten inches in thickness. In this district, the fields are not divided by 
 hedge rows, but by walls built with the stone brush, without mortar.
 
 xlvi 
 
 tic day. 2. Chalk. 3. Green sand. And, 4. The 
 oolitic series. 
 
 The limestone beds of the upper division of the 
 oolitic series (Purbeck, Portland, and Kimmeridge 
 beds) are extensively quarried in Wiltshire. The 
 principal quarries are at Fonthill, Tisbury, Chicks- 
 grove, and Chilmark. 
 
 Berkshire. 
 
 Berkshire contains, 1. Plastic clay. 2. Chalk. 
 3. Green sand. 4. Upper and middle oolite. 
 
 The building materials of this county are 
 chiefly bricks and chalk lime. The brick earth 
 belongs to the plastic clay formation, and is exca- 
 vated in considerable quantities at the Catsgrove 
 fields, near Reading, and other large quarries of 
 brick earth on Saint David's hill, west of Read- 
 ing, where this formation is about forty feet in 
 thickness. (Buckland's Geology Trans, vol. iv.) 
 The red clay of Reading, on the north of the 
 Hog's-back, and at East Horsley, is perfectly iden- 
 tical with that of Meudon in France ; nor has this 
 colour been found equally intense in any other clay. 
 The bricks made of this clay are of a bright Roman 
 ochre colour. (Conybeare, Geology of England 
 and Wales, Notes.) 
 
 The quarries of chalk in the neighbourhood of 
 Reading are extracted largely from under the sands
 
 xlvii 
 
 and clays, by means of shafts and levels, to be burnt 
 into lime (Buckland). 
 
 Siliceous grit stones (called sarsden stones and 
 the gray weathers) are distributed in a loose state 
 over the Berkshire and Wiltshire downs, and ap- 
 parently, do not belong to the contiguous strata. 
 
 Middlesex. 
 
 The county of Middlesex contains, London and 
 plastic clay. 
 
 A particular account of the London clay will 
 be found in the first Chapter of this Treatise, accom- 
 panied by some sections of the strata. The first 
 fifteen or twenty feet of the clay stratum is of a 
 chesnut colour, but at a greater depth, changes to 
 light blue ; and finally, passes into a dull black. 
 The upper stratum is generally used for bricks, and 
 the lower ones for tiles ; either will answer the pur- 
 pose for brick making, but the blue clay will burn 
 to brick of a deep red colour. This may, however, 
 be prevented by the admixture of a certain propor- 
 tion of chalk with the clay (in a pug mill), which 
 will then burn to a bright straw or ochre colour. 
 The number of brick fields in Middlesex is consider- 
 able. Immense quantities have been made at Hack- 
 ney, Kingsland, City-road, Hounslow, Brentford, 
 and Cowley, near Uxbridge. The bricks from the 
 latter field are much valued, on account of their 
 bright yellow colour, and general good quality.
 
 xlviii 
 
 Surrey. 
 
 The geological formations which are devfeloped 
 in this county , consist of the chalk, green sand, and 
 Wealden. 
 
 The chalk division comprises, 1. The upper chalk. 
 2. The lower chalk. And, 3. The chalk marie. 
 The green sand division contains, 1 . The upper green 
 sand, containing sand intermixed with green par- 
 ticles (chlorite), indurated marie, and calcareous 
 sandstone. 2. The gault, consisting of a series of 
 clay beds passing into calcareous marie. 3. The lower 
 green sand, containing beds or strata of gray, yellow, 
 and greenish sands, ferruginous sands, sandstones, 
 clays, &c., and siliceous limestones. The Wealden 
 contains, 1. Weald clay. 2. A series of sand, sand- 
 stones, clays, and calcareous grits passing into 
 limestone. 
 
 The material furnished by this county, for 
 architectural or engineering purposes, is now chiefly 
 confined to the supply of lime for the use of the me- 
 tropolis, and adjacent places; the best kind is that 
 manufactured from the indurated chalk marie. 
 
 The kilns are situated at Dorking, Croydon, 
 Hallam, Riddlesdown, Merstham, Guildford, Reigate, 
 Sutton, Carshalton, &c. ; and the principal quarries 
 are those of Croydon, Dorking, Sutton, Epsom, 
 Leatherhead, Bookham, Effingham, Horsley, Clau- 
 don, Stoke, Guildford, and Puttenham, on the north-
 
 zlix 
 
 fern side of the Downs; and those at Godstone, 
 Catterham, Reigate, Merstham, Buckland, and 
 Betchworth, on the southem side, 
 
 The upper green sand division supplies a sand- 
 stone which was formerly employed in important 
 buildings, and we are informed that a patent of 
 Edward III. exists, authorizing the working of the 
 quarries at Gatton and contiguous places, for the 
 supply of stone for Windsor Castle. Henry the 
 Seventh's chapel at Westminster, and the church at 
 Reigate, &c., also furnish examples of its employ- 
 ment as a building stone. 
 
 The older quarries are now abandoned, and the 
 stone has been for some years past procured at 
 Merstham. According to an examination made by 
 Mr. Webster,* its constituents appear to be siliceous 
 sand and mica, cemented by an earthy carbonate of 
 lime, with a very small quantity of dark green par- 
 ticles. Mr. Webster observes, that " this latter 
 substance is not so abundant as is generally the case 
 in the green sand formation, a glass being necessary 
 to observe it, but it is never totally wanting." 
 
 The stone from these quarries is very unfit for 
 the purposes of masonry, in consequence of the car- 
 bonate of lime contained in it being impregnated with 
 earthy matter. If used without the precaution of 
 drying, it soon falls to sand; but it may be employed 
 with advantage as a fire stone, or in such situations 
 as may secure it from the attacks of the weather. 
 
 * See Geological Transactions, vol. v. part 2. p. 355. 
 d
 
 1 
 
 The calcareo-siliceous grits of the green sand 
 formation vary considerably in their state of indura- 
 tion : stone has recently been procured from Leith 
 Hill, about six miles from Dorking, of a much better 
 quality than the Merstham stone. The villa of Mr. 
 Spottiswoode, and some other buildings lately erected 
 near this place, may be referred to as practical 
 examples of its application. The bricks manufac- 
 tured in the county of Surrey are mostly of a red 
 colour, but are much inferior in quality to the gray 
 stock of Middlesex, Kent, and other districts covered 
 by the London clay. 
 
 Fire bricks and tiles of good quality are ma- 
 nufactured at Ewell, the materials being derived 
 from the beds belonging to the plastic clay formation, 
 and, occasionally, blocks of an indurated sandstone 
 are obtained from the deposit, called Bagshot sand 
 (upper marine formation), sufficiently firm for the 
 purposes of masonry. These two latter deposits are, 
 however, but feebly represented in the county of 
 Surrey. 
 
 Kent. 
 
 The maritime county of Kent contains portions 
 of the following formations : 1. London clay. 2. 
 Plastic clay. 3. Chalk. 4. Green sand. And, 5. 
 Upper oolite. 
 
 Building materials of the following kinds may 
 be obtained with facility from various parts of the
 
 li 
 
 county: 1. From the London clay, Septaria, or 
 English cement stone, from the Isle of Shcppy j 2. 
 From the chalk, thalk marie ; Lime-kilns and 
 chalk-quarries are situated at Greenhithe, Northfleet, 
 Gravesend, Rochester, Chatham, Chevening, Dover, 
 and at other places on the coast; 3. From the 
 green sand, Kentish rag : the western part of the 
 county of Kent is the principal depository for the 
 Kentish rag-stone. The rock forms the sub-stratum 
 of a soil, called hassock, or stone shatter, which is a 
 mixture of sandy loam and fragments of the rock ; 
 blocks of stone, of considerable dimensions, are fre- 
 quently obtained within a few inches of the surface. 
 This stone belongs to the lower green sand formation ; 
 it is a calcareo-siliceous grit, possessing a consider- 
 able degree of induration, and is much used in various 
 parts of the county ; it is a substantial building stone. 
 The beds between the chalk and oolites also contain 
 sandstones of various kinds : at Penshurst, a tender 
 ferruginous sandstone (from the iron sand formation) 
 is quarried for building ; and in the neighbourhood 
 of Tunbridge, a hard quartzose ferruginous stone is 
 extensively employed; the latter is esteemed as a 
 good weather stone ; 4. From the upper oolite. The 
 argillo-calcareous beds of the oolitic formation, in the 
 county of Kent, are occasionally worked fi the lime- 
 stones they afford, but the stone is not sufficiently 
 durable for masonry. The limestones of this series 
 are subsequently noticed by the names of Petworth 
 and Purbeck marble. The plastic clay formation 
 d2
 
 "lii 
 
 supplies brick earth and sands of excellent quality, 
 immense quantities of stock and other bricks have 
 been supplied to the London builders from the fields 
 at Erith, Lewisham, Bromley, &c. 
 
 Sussex. 
 
 The maritime county of Sussex contains, 1. 
 Chalk. 2. Green sand. And, 3. The upper division 
 of the oolitic series. The materials supplied by the 
 chalk and green sand formations, are similar to those 
 found in the counties of Surrey and Kent. Lime from 
 the chalk marie may be procured at Lewes, Brighton, 
 Shoreham, Worthing, East Grinstead, Rye, &c., 
 and at many other places in the chalk district. The 
 weald of Sussex contains limestone, limestone marble, 
 sandstone, and ironstone. The ironsand deposit (one 
 of the beds between the chalk and oolites) is laid 
 open at Horsham, Hastings, &c., and produces a 
 very durable sandstone. 
 
 The groin work at Battle Abbey is of freestone 
 belonging to this series ; it is also used for copings, 
 and in the neighbourhood of Horsham this formation 
 yields flagstones for paving.* The tender limestone 
 called P|[worth marble, is procured from the weald 
 clay in the neighbourhood of Petworth ; its texture is 
 earthy and friable ; the stone is therefore unfit for 
 exposure. The quarries (with the exception of those 
 
 * Conybeare, Geol. of England and Wales. Notes, p. 137.
 
 near Kirdford and North Chapel, in Surrey) are now 
 abandoned. 
 
 Hampshire.* 
 
 The county of Hampshire contains, 1. London 
 clay. 2. Plastic clay. 3. Chalk. And, 4. Green sand. 
 The chalk hills cross the county from east to west. 
 The chalk is quarried extensively throughout this 
 district, and near the coast ; two kinds of lime are 
 produced, one from the white and the other from the 
 gray chalk ; the lime from the latter is equal to the 
 Dorking lime, and is much used. The plastic clay 
 and green sand formations of this county and the 
 Isle of Wight produce sandstones and conglomerates 
 available for building. 
 
 The following varieties are ordinarily used as 
 building materials. 1. Between Milton and Christ- 
 church a ferruginous sandstone. 2. A porous grit 
 or quarry stone, obtained from the northern foot of 
 the Downs, and found in detached masses. 3. A 
 liver-coloured, ferruginous sandstone from the southern 
 part of the island. 4. A calcareous grit from the 
 marl pits eastward of Staples heath. 5. A close gray 
 limestone procured from the northward of Arereton 
 downs. 6. A marly variety of freestone. And, 7. 
 Conglomerates, used for paving and flooring ; these 
 are procured in large quantities from near Sandown 
 
 * The Isle of Wight contains the following formation. 1. Fresh water 
 beds. 2. Plastic day. 3. Wealden. 4. Green sand. And, 5. The Chalk.
 
 liv 
 
 fort. Brick earth and potter's clay of excellent 
 quality abound in various parts of the county, and 
 the bricks from Southampton are a substantial and 
 elegant material for building. 
 
 Dorsetshire. 
 
 The county of Dorset contains, 1. Plastic clay. 
 2. Chalk. 3. Green sand. 4. The Oolitic series. 5. 
 Lias. 
 
 A considerable portion of the county of Dorset 
 is occupied by the chalk formation and its accom- 
 panying beds, above and below. The information 
 already given, concerning the beds of this formation, 
 and the materials which they supply, will be found 
 sufficiently indicative of the resources of such part of 
 this county as is occupied by these formations. 
 
 To the engineer or builder, the most important 
 part of the county of Porset is that occupied by the 
 Isles of Portland and Purbeck, the grand depositories 
 of the finer architectural materials of this county. 
 The island of Portland consists of black shiver, 
 covered with limestone (Middleton). The north end 
 of it is about 400 feet above the sea, and that of the 
 south is supposed not to exceed 100 feet in height. 
 
 The quarries are on the eastern and western sides 
 of the island, and the cap of stone averages 100 feet 
 in thickness. The stone is in layers, varying in 
 thickness, with partings of clay, shiver, flint, &,c. The
 
 best quarries are at Kingston, Worth, Langston, and 
 Swanwich ; other quarries are situated at Wareham, 
 Morden, and near Dunshay. The quarries are also 
 known by various names, such as Waycroft quarry, 
 Goslings quarry, Winspit quarry, Maggott quarry, 
 &c., and lias is extensively quarried at Lyme llegis. 
 The quality of the Portland and Purbeck stone, lias, 
 &c., will be found described in the 5th chapter. 
 
 Somerset. 
 
 The county of Somerset contains, 1 . Green sand. 
 2. Loiver oolite. 3. Lias. 4. New red sandstone. 
 5. Coal. 6. Mountain limestone. 7. Clay-slate, gray- 
 wacke, and some small patches of chalk. 
 
 The lower division of the oolitic series is well 
 developed in this county, and extensively worked for 
 the supply of the well-known Bath stone. The 
 quarries around Bath are very numerous ; the most 
 important are Box, Coombe down, and Farley down, 
 near Bath ; and at Doulting, near Shepton Mallet, 
 are some celebrated quarries of valuable freestone. 
 The lias, which forms the base of the oolitic series, 
 is extensively quarried in this county ; a considerable 
 quantity is procured from the quarries near Bath, and 
 at Watchet, St. Decuman's, Glastonbury, Somerton, 
 Shepton Mallet, &c. 
 
 Mr. Horner, in describing the Somersetshire 
 lias,* observes, that " all the strata of this limestone, 
 
 * Geology of the south-western pail of Somersetshire, by Mr. 
 Ilorner, Geol. Trans., v.pl. iii.
 
 Ivi 
 
 though externally very similar, are not of the same 
 mineralogical composition, for they have very distinct 
 properties. Some of them yield a lime which pos- 
 sesses, in a most eminent degree, the property of 
 setting under water : these are generally the thinnest 
 strata, are of a light blue colour, and compact earthy 
 texture; on each surface of the stratum, and at the 
 joints, the colour is changed to a light brownish yel- 
 low or cream colour, which is of different thicknesses ; 
 in some places extending so far into the interior of 
 the stratum, that the blue colour is nearly obliterated. 
 The other variety of the limestone is of a much 
 darker colour, but is most particularly distinguished 
 by the strong foetid smell it gives out wiien struck 
 by the hammer, and when it is burning in the kilns. 
 It is always in thicker strata than the other variety, 
 and abounds in organic remains ; it is also very much 
 penetrated by pyrites in many places. These foetid 
 strata have much less the property of setting under 
 water, and are best adapted for agricultural purposes, 
 for which the other are very unfit." 
 
 The first mentioned variety of limestone is by 
 the quarry-men called blue lias or building lime, 
 and the latter, black lias or ground lime ; the strata 
 are generally less adapted for building lime the lower 
 they go. The limestone on the eastern side of the 
 Quantock hills is chiefly of the crystalline kind, but 
 of variable quality, and accompanied by the red 
 sandstone and graywacke of the county. The prin- 
 cipal Quantock quarries in the south-western part t>f
 
 Ivii 
 
 Somersetshire, may be enumerated as follows : 
 Binfords, Westcot, Treborough,* Leigh, Doddington, 
 Triern farm, Ely green, Cannington park, &c. 
 (Homer). 
 
 A very fine grained granite, provincially called 
 " pottle stone" was formerly quarried at the foot of a 
 hill a few miles north-east of Taunton.f The quality 
 of the various kinds of Bath stone is fully described in 
 the 5th chapter of the Treatise. 
 
 Devonshire. 
 
 The county of Devon contains, 1. Green sand. 
 2. New red sandstone. 3. Millstone grit. 4. Granite, 
 trap, &c. 5. Clay-slate. And, at Chudleigh, a por- 
 tion tfclay. 
 
 The granite quarries are situated on the ele- 
 vated tract called Dartmoor, in the south-western 
 part of the county, and are surrounded by a district 
 of argillaceous slate. The transition slate occupies 
 the northern part of the county, including Exmoor. 
 The red sandstone occupies the lesser tracts of the 
 county, and skirts the base of the last-mentioned dis- 
 trict, extending north-eastward into Somersetshire, 
 and westward as far as Hatherleigh. The green 
 
 At Treborough, a very excellent roofing slate is to be procured. 
 Horner, Geol. Trans. 
 
 \ There are .extensive limestone quarries iu the neighbourhood of 
 Bristol.
 
 Iviii 
 
 sand constitutes the largest portion of the hills 
 in the south-eastern part of the county (Lewis). 
 
 The extensive quarry of Heavitree (red sand- 
 stone formation) is situated about a mile and a half 
 from Exeter, on the road to Honiton. The stone is 
 a stratified conglomerate, compact and tenacious, but 
 passes into a tender and friable sandstone. Dr. Ber- 
 ger * (to whom we are indebted for this information) 
 states, that owing to the presence of a considerable 
 quantity of calcareous particles in the stone, it might 
 be very easily mistaken for limestone ; it also con- 
 tains particles of other rocks. 
 
 Poucham quarry is about two miles N. N. w. of 
 Exeter. The rock is an amygdaloid, the nodules of 
 which are chiefly calcareous, and much stained with 
 the oxide of iron. 
 
 There are three or four quarries at Thorverton, 
 seven or eight miles north of Exeter, in the same 
 amygdaloid al rocks ; but the composition of the rock 
 varies considerably in different places. 
 
 The limestone of the cliffs from Stonehouse 
 Pool to Catwater and Mount Batten is formed of a 
 compact limestone, which breaks into large flakes 
 with a semi-conchoidal fracture. It is of a yellowish 
 white colour, and, when quarried, is blasted with 
 gunpowder. On the side of Catwater this limestone 
 is of a bluish colour, and crystalline grain, but inter- 
 sected by veins of calcareous spar, in many places. 
 
 * Dr. Berger " On the Physical Structure of Devonshire and Corn- 
 wall." Geol. Tians. vol. i. p. 101.
 
 Hx 
 
 The transition limestone of Plymouth has al- 
 ready been sufficiently described ; there is, however, 
 a quarry of it on the left bank of the Plym, belong- 
 ing to Lord Borringdon. The stone is of a blackish 
 brown colour, containing rhomboidal plates of calca- 
 reous spar. It is remarkable, that in the same 
 stratum, it suddenly assumes all the characters of a 
 shining slate, and, in this state, effervesces less 
 briskly with acids. 
 
 Cornwall. 
 
 The county of Cornwall contains, 1. Millstone 
 grit. 2. Granite. 3. Trap rocks. 4. Clay and 
 graywacke slate. 
 
 The greater part of the county of Cornwall is 
 occupied by the Killas, a coarse argillaceous schist, 
 which is found in every part of Cornwall with the 
 exception of the spaces occupied by the granite. 
 
 The granitic districts are four in number. The 
 first is nearly bounded by the church towns of 
 Northill, St. Neot's, Blislind, St. Breward, and St. 
 Clether ; the second, by Llanlivery, Roach, St. Den- 
 nis, St. Stephen's, St. Austell, and St. Blazey ; the 
 third, by those of Constantine, Crowan, Redruth, and 
 Stithians ; the fourth occupies the western extremity 
 of the county, from St. Paul and Tennor, to the 
 Land's End. There are also four small spots of 
 granite ; the first between Calstock and Callington, 
 the second east of Redruth, a third west of Breage 
 and St. Michael's Mount.
 
 Ix 
 
 There are some thin beds of crystalline lime- 
 stone near Padstow, in the parishes of Carantoe 
 and Lower St. Columb, also between Liskeard and 
 the Tamar. Beds of china and other clay are found 
 in various parts of the county (Lewis). 
 
 It would appear that the granitic rock of Cal- 
 stock possesses a certain degree of stratification, for 
 in working the stone, the quarry men split it with a 
 great number of wedges. The pool holes are first 
 sunk with the point of a pick, about four inches 
 apart, according to the size and supposed strength of 
 the stone. 
 
 Mr. Smeaton states, in his " Narrative," that 
 he has frequently seen, in this county, " posts of 
 granite twelve feet long, and not above eight inches 
 square, used instead of wood, for the mere purpose of 
 supporting a hovel" "But it is to be constantly 
 observed," he continues, "that the strength of the 
 stone on each side of the bisection is so managed, 
 as to be nearly equal, otherwise the split will con- 
 stantly encroach on the weaker side." 
 
 Isle of Man. 
 
 The Isle of Man contains, 1. Mountain lime- 
 stone. 2. Clay slate. And, 3. New red sandstone. 
 
 In this island there are several quarries of 
 valuable freestone. The dark gray or black marble 
 so much employed in the time of Wren, was pro- 
 cured from this island. The external steps of St.
 
 Ixt 
 
 Paul's cathedral were, it is stated, procured from 
 these quarries. 
 
 The intermediate strata of the formations which 
 we have enumerated are of almost infinite variety, 
 but, when considered as substrata for building upon, 
 may be arranged in the following order Bog earth, 
 Clay, Gravel, and Sand. We shall have occasion in 
 the course of the following Treatise, to point out in 
 detail, the precautions necessary to be adopted, 
 when building upon soils so varied in character ; in 
 this place, however, few general remarks appear 
 necessary. The most recent and successful in- 
 stance of forming a foundation on moss or bog, is 
 exhibited on the Liverpool and Manchester railway. 
 Chat Moss is a vast morass, situated on the north 
 side of the turnpike road, leading from Manchester 
 to Liverpool, containing about 6,000 statute acres, 
 the entire extent covering about twelve miles. 
 The composition of this bog is identical with the 
 red bog of Ireland, and the white flow moss of 
 Scotland. The vegetable mass retains the water 
 similar to a sponge. Every fibre contains a portion 
 of water, and the tenacity with which it continues 
 to hold it, gives to the whole a semi-fluid quality, 
 not always free from danger to the neighbouring 
 land. The depth of this bog is, in some parts, forty 
 feet, resting, of course, on what was the original sur- 
 face; the general drainage was therefore accom- 
 plished with little difficulty. The Liverpool and 
 Manchester railway crosses Chat moss, in a line of
 
 Ixii 
 
 nearly five miles in length. In forming the em- 
 bankment at the eastern boundary (twenty feet in 
 height), an immense mass of earth was thrown in 
 and disappeared, before anything like a palpable 
 foundation for the road could be obtained. 
 
 In forming the embankments on the moss, 
 677,000 cubic yards of bog earth were dug up, and 
 the water being ejected, so as to render it solid and 
 fit for the purpose, its quantity was reduced to about 
 277,000 cubic yards. The embankment across 
 Parr's Moss, three quarters of a mile in length, was 
 composed of 144,000 * cubic feet of clay and stone, 
 procured from the Sutton inclined plane.f 
 
 In building upon a substratum of London clay, 
 it is highly necessary that the excavations should be 
 continued below what may with propriety be called 
 the weather line. The London and other similar clays, 
 are remarkable for the natural fissures which they 
 contain, many of which are either wholly or parti- 
 ally filled with calcareous spar or sulphate of barytes, 
 but in exposed situations, and in the summer season, 
 many additional cracks become visible, and extend 
 to a considerable depth. On an atmospherical 
 change taking place, the fissures close, and the clay 
 swells ; the enormous pressure thus exerted by the 
 water contained on or below the substratum, will 
 effectually disturb the equilibrium of buildings of 
 moderate weight. Great attention is also required 
 
 * Qy. yards ? 
 
 t See " Wheeler's History of Manchester," 1836.
 
 Ixiii 
 
 in passing from one stratum to another. In all 
 cases of soft soils, the upper stratum should be either 
 wholly cut through, or a sufficient depth of the 
 natural soil should be left under the foundations, 
 equal to bear the superincumbent pressure. Great 
 danger is, therefore, to be apprehended in breaking 
 the upper crust of a new stratum ; if a new stratum 
 is to be passed into, the excavation should be carried 
 down to the more consolidated part. 
 
 The blue and brown argillaceous deposit so exten- 
 sively distributed over the eastern counties, contains 
 nodules of chalk, and masses of various other rocks 
 and fossils from nearly every secondary formation in 
 England. Doctor Mitchell, in a paper lately read 
 at a meeting of the Geological Society (November 
 5th, 1838), gives the following localities, near which 
 the peculiar features of this deposit may be traced ; 
 Norfolk : Cromer, Norwich, Harleston, and Diss. 
 Suffolk : Lowestoff, Southwold, and Woodbriclge. 
 Essex : Maldon, Kelvedon, Braintree, Castle Hed- 
 dington, Navestock, and Upminster. Cambridge- 
 shire : Ely, Caxton, and Arrington. Huntingdon- 
 shire : The district behind Huntingdon and Peter- 
 borough, Huntingdon and Caxton. Bedfordshire : 
 Castle hill near Bedford. Buckinghamshire : The 
 line of the London and Birmingham Railway, near 
 Fenny Stratford, and the Linslade tunnel, near 
 Leighton Buzzard. Middlesex : Finchley and Mus- 
 well hill. The principal localities for the accumu- 
 lation of rocks from distant formations, are the Stag
 
 Ixiv 
 
 Inn, near Diss; Holy well, near Norwich ; Ballingdon 
 Hill, near Sudbury; Newnham, near Baldock, and 
 Muswell Hill, Middlesex ; at each of which points 
 are found nearly all the following rocks : hard and 
 soft chalk, with tabular and other flints, oolite, 
 cornbrash, lias, mountain limestone, trap porphyry, 
 sienite, and granite,* 
 
 Should the substratum consist of a gravelly 
 deposit, its nature and extent should if possible be 
 ascertained previous to the commencement of the 
 works, for strata of this description offer more 
 remarkable phenomena to the notice of the engineer 
 than any other. 
 
 It should be remarked, that although sands and 
 gravel " faithfully represent those rocks from which 
 they are derived," yet vast accumulations of gravel 
 are deposited in many parts of the country, derived 
 from rocks whose localities are far removed from 
 those deposits. The post-diluvian aggregations, 
 notwithstanding their great thickness in some places, 
 are generally loose and shingly in their nature, and, 
 if adopted as a substratum for important works, re- 
 quire considerable artificial consolidation. In the 
 vicinity of London, the gravel chiefly consists of 
 rolled flint pebbles, probably derived from the chalk 
 formation ; but to the westward of the metropolis, 
 the gravel under the alluvium is intermixed with a 
 considerable quantity of quartzose pebbles. 
 
 It appears that the nearest quartzose rocks in situ, 
 
 * Athenaeum, No. 576, p. 811.
 
 Ixiii 
 
 are those which constitute the Lickey range, near 
 Bromsgrove, in Worcestershire ; the vast ruin of 
 whose rocks has been traced* from their source 
 through Warwickshire, Oxfordshire, and the valley 
 of the Thames downwards, towards London. 
 
 The gravel pits of Hyde Park and Kensington 
 contain a considerable quantity of quartzose debris, 
 much of which is either in a state of comminution 
 or decomposition. Deposits of this nature are easily 
 identified by their loose structure and heterogeneous 
 composition, while the real diluvium is mostly held 
 together With a calcareous or ferruginous cement, 
 in considerable stratified beds. 
 
 The gravel of Lichfield is an example of a de- 
 composing stratum, well worth the attention of the 
 student or engineer. *f 
 
 Foundations upon sandy beds have been formed 
 with considerable success. The erection of the light- 
 house upon Spurn Point, by the late Mr. Smeaton, 
 is a useful example to the student, and shows that a 
 firm sand will resist the insertion of piles after the 
 depth of nine feet. J 
 
 The bridge over the estuary of the Lary, at 
 Plymouth, is another successful example of building 
 upon a sandy bottom. An excellent memoir on this 
 subject will be found in the first volume of the 
 " Trans. Inst. C. E." 
 
 * See Dr. Buckland on this subject, vol. 5, part ii., Geol. Trans, 
 f See Aiken on the Lichfield Gravel, Geol. Trans, vol. 4. 
 See Smeaton's Narrative."
 
 Ixiv 
 
 Piling an alluvial sands, in low situations, or on 
 the banks of rivers, is highly objectionable, inasmuch 
 as the absorption of water from above, or the upward 
 filtration from a subjacent retentive stratum, com- 
 bined with the influence of the tides, will most cer- 
 tainly subject the buried timber to those changes of 
 temperature, and alternate dryness and moisture, 
 which are so destructive to even the most compact 
 and solid materials. 
 
 The following materials have been carefully 
 examined and experimented upon. The results will 
 be given in the course of the Treatise : 
 
 Strata above the Chalk. 
 
 From the London clay and sands above: 
 Highgate and Bagshot sands, and septaria from 
 Primrose-hill. Sands from the plastic clay forma- 
 tion. 
 
 From the chalk : Merstham and Dorking 
 chalk marie ; lime made from ditto. 
 
 From the Green sand: Sandstone from the 
 Merstham and Leith-hill quarries, Surrey ; Kentish 
 rag from the Weald.
 
 Ixv 
 
 From the Weald clay : Specimen from Pet- 
 worth, and specimen of Purbeck from the foundation 
 of Old London Bridge. 
 
 From the Iron sand: Sandstone from Pens- 
 hurst, Kent, and Sandy, Bedfordshire. 
 
 Oolitic series, upper division : Limestone from 
 Aylesbury, Purbeck, and Portland. 
 
 Middle division: Red sandstone from Wey- 
 mouth; Limestone from Chippenham (Wilts,) and 
 Lincoln. 
 
 Lower division: Limestones from Ketton, 
 (Northamptonshire), Coombe Down, Lansdown, 
 Farley Down, and Box quarries, Bath (Somerset), 
 Stamford (Huntingdonshire), and Newport Pagnel 
 (Bucks) ; Sandstones from Northampton, Fenny 
 Compton, Blisworth, and Daventry. 
 
 Lias : From Bath (Somerset), and from near 
 Stoke Prior (Worcestershire). 
 
 New red sandstone : From the Liverpool tun- 
 nel, and Oldbury (Warwickshire), Tamworth (Staf- 
 fordshire), andRuncorn (Cheshire). 
 
 Magnesian limestones : From Brodsworth, 
 Ripon, Doncaster, Quarry Moor (Yorkshire), Dur- 
 ham, and Nottingham. 
 
 Transition limestone : Plymouth. 
 
 From the carboniferous series : Limestones 
 from Chesterfield and Matlock (Derbyshire), Roach 
 Abbey, Richmond (Yorkshire), Dost-hill quarries 
 (Staffordshire) ; Sandstones Warsall stone, Rainton
 
 Ixvi 
 
 quarry, Pateley stone, Moor stone, Bramley Fall, 
 Mexborough stone, Holton stone, Kirby stone, Leeds 
 flagging, Idle flagging, and Sheffield stone (York- 
 shire), Heddon quarry (Northumberland), and Stokes 
 quarry, Amington (Staffordshire). 
 
 Granites, Sienite : From Great Malvern, 
 Dublin, Hayter (Devonshire), Constantine (Corn- 
 wall), Aberdeen (Scotland), and Sandstone from the 
 Cragleith quarries (Scotland).
 
 CHAPTER I. 
 
 PRELIMINARY OBSERVATIONS. REMARKS ON THE GENE- 
 RAL ORDER AND SUCCESSION OF STRATA. ON THE 
 EXAMINATION OF STRATA AND DESCRIPTION OF 
 BORING APPARATUS EMPLOYED FOR THAT PURPOSE. 
 NATURE OF STRATA ABOVE THE LONDON CLAY. 
 SECTION'S OF STRATA IN THE NEIGHBOURHOOD OF 
 LONDON, &c. 
 
 THE great importance attached to the study of 
 the Science of Architectural Construction, and the 
 vigour with which analytical investigations on this 
 subject have of late years been followed up, has given 
 to the opinions of the British Architect a weight 
 and respectability of character, that yields to none 
 of his professional brethren of continental note. 
 The impetus given to that branch of architectural 
 science called Civil Engineering, by the vast and 
 numerous projects for the purpose of railroad con- 
 veyance, has called into operation a further develop- 
 ment of those energies which had previously been 
 so successfully employed in the art of Bridge Build- 
 ing, and which called forth the following elegant 
 encomium upon native talent and individual enter- 
 prise, from a celebrated French engineer who (al- 
 luding to Waterloo Bridge) in a memoir addressed 
 
 B
 
 to the French Institute, thus apostrophizes his 
 subject : 
 
 " If, from the incalculable effect of the revolu- 
 tions which empires undergo, the nations of a future 
 age should demand one day what was formerly the 
 new Sidon, and what has become of the Tyre of the 
 West, which covered with her vessels every sea? 
 the most of the edifices devoured by a destructive 
 climate will no longer exist to answer the curiosity 
 of man by the voice of monuments; but the Water- 
 loo Bridge, built in the centre of the commercial 
 world, will exist to tell the most remote generations : 
 here was a rich, industrious, and powerful city ! 
 The traveller, on beholding this superb monument, 
 will suppose that some great prince wished, by many 
 years of labour, to consecrate for ever the glory of 
 his life by this imposing structure. But if tra- 
 dition instruct the traveller that six years sufficed 
 for the undertaking and finishing of this work if 
 he learns that an association of a number of private 
 individuals was rich enough to defray the expense 
 of this colossal monument, worthy of Sesostris and 
 the Ca3sars, he will admire still more the nation 
 in which similar undertakings could be the fruit of 
 the efforts of a few obscure individuals lost in the 
 crowd of industrious citizens." 
 
 It is not, however, the skill or ability displayed 
 by the architect in the structure alone, that enables 
 us to judge of his merits as a practical builder, 
 or that evinces his judgment as an engineer. The
 
 attributes of foresight and prudence, so eminently 
 calculated to command success in every relation of 
 life, is, in the case of the architect, a matter of con- 
 stant and particular application, and upon the due 
 observance of which depends his fame and character 
 as an artist, and his success as a skilful practi- 
 tioner. To the many, the scientific labours of the 
 architect are but little known and less understood. 
 Buried beneath the bed of rapid rivers, surrounded 
 by the waves of the ocean, or deeply seated upon 
 the firm consolidated stratum of its parent bed, the 
 foundations of his works the practical application 
 of the study of years lay concealed from the view 
 of the thousands that admire or impugn the taste of 
 him whose labours are supposed to end with the pro- 
 duction of a tasty facade from the drawing board. 
 
 The important points involved in the considera- 
 tion of the present subject has induced the Author 
 to devote this Chapter to some general observations 
 concerning the nature of stratification, and, above 
 all, to point out to the inquiring student the neces- 
 sity of his considering the study of the science of 
 Geology, as embracing a most valuable and signifi- 
 cant acquisition to his stock of scientific information. 
 " Geology (says the Rev. W. D. Conybeare*) being 
 the knowledge of the earth's structure, as far as it 
 lies open to our observation, the fundamental point 
 on which it rests is the ascertaining the order 
 in which the materials constituting the surface 
 
 * Geology of England and Wales. 
 B "2
 
 of our planet (far beyond this our observation 
 cannot penetrate) are disposed. The superficial 
 and hasty observer might suppose that these mate- 
 rials are scattered irregularly over the surface, and 
 thrown confusedly together ; but a slight degree of 
 attention will prove that such a conclusion would 
 be entirely erroneous." The continued change of 
 locality to which man in his less civilized state was 
 subject, must undoubtedly have led to some particu- 
 lar observations relative to the soil that was to yield 
 him its produce for his support. But the extension 
 of his observations, for any further purpose on this 
 point, may be readily doubted, when we consider the 
 migratory character of his life, and the temporary 
 structure of the rude abode that was formed, rather 
 for the purposes of present shelter and repose than 
 for those domesticated comforts and conveniences 
 that mark the progressive stages of his civilization 
 and refinement. In directing attention to a com- 
 paratively modern branch of study, namely, Geology, 
 we shall endeavour to show in what manner the 
 truths unfolded by that science may be rendered of 
 the greatest available service to the student in archi- 
 tecture, and its professors, whether civil or military. 
 The researches of the geologist having placed 
 before us certain facts relative to the formation of 
 the strata, of our globe, it will be necessary, in 
 treating on this subject, to adopt, to a certain extent, 
 that methodical arrangement exhibited in their most 
 approved treatises. But while we shall have occasion
 
 to recur to geological formations in treating on the 
 varieties of building stone, the discussions on the 
 natural phenomena connected with our investigations 
 embrace such an extensive field of inquiry, and is 
 withal so peculiarly the province of the scientific 
 geologist, that a reference* on the part of theAuthor 
 to those standard productions that are most likely 
 to reward the researches of the student must be 
 considered sufficient for this purpose. We profess 
 only to point out the application of this study to the 
 purposes of architectural science. 
 
 The distribution of the various strata that form 
 the crust of the earth are, by an Intelligent Cause, so 
 placed before the observation of man, as to point 
 out readily the peculiar characteristics of a country 
 suitable either for the establishment of a city, the 
 occupation of the agriculturist, or the site of the 
 cyclopean works of the workers in metal. 
 
 The manner in which the various strata a?e 
 successively presented to view on the surface of the 
 earth is by what is termed (geologically) the " out- 
 crop, or basset of the strata." This remarkable ap- 
 pearance originates in consequence of the different 
 strata successively overlapping and emerging from 
 beneath each other, f thereby forming a series of 
 
 * Phillips and Conybeare, " Geology of England and Wales." In 
 the elegantly written introduction to that work, numerous references 
 are given of considerable importance, and to these I must refer the 
 student who wishes to extend his geological inquiries, only adding to 
 them the late celebrated " Bridgewater Treatise" of Professor Buckland. 
 
 t This natural arrangement of the strata enables us to become
 
 zones or belts, marking the variations of soil, and 
 distinguishing in many instances one county from 
 another. From whatever point we proceed, consi- 
 dering (for example) London as the centre, the 
 same phenomena and' the same distribution of 
 strata exist subject, however, to occasional inter- 
 ruptions, dislocations, &c., arising from the external 
 agency of atmospherical influences, irruptions of 
 water, or of the no less violent agency of volcanic 
 fires. The operations of the architect, in his search 
 after a solid substratum, do not extend to any very 
 great depth ; for should the soil prove treacherous, 
 he has other and artificial aids for remedying a 
 defect which would probably otherwise require 
 extensive excavations. Previous to entering upon a 
 description of these artificial methods, it will be 
 requisite to point out some of the more prominent 
 strata that will be most likely to command the 
 attention of the young architect or engineer. Geo- 
 logists have generally agreed to the following classi- 
 fication of the strata as they appear on the surface 
 of the earth : The alluvial, the diluvial, and the 
 regular strata, consist of various beds or layers of 
 sand, clay, and limestone, each of which, with their 
 separate layers, are also designated by the compre- 
 hensive terms of siliceous, argillaceous, and calca- 
 reous masses, the most prominent of which in this 
 island are the chalk and the limestone. 
 
 acquainted with the nature and properties of the beds or layers, other- 
 wise inaccessible from their extreme depth in a vertical direction.
 
 The alluvial stratum is that peculiar deposit 
 which is formed under our immediate observation, 
 and consists of accumulations of sand and shingle 
 along the sea-coast, in estuaries, the alluvial depo- 
 sitions forming new lands on the banks of rivers, 
 lakes, &c., and other apparently minor causes, but 
 which in process of time gradually operate and 
 effectually change the face of well-known localities. 
 The immense quantity of shingle or beach which 
 is now, and has, for some time past, been collect- 
 ing together at the foot of the town and port of 
 Dover, is an example of the formation of this kind 
 of deposit worthy the attention of the engineer.* 
 
 The diluvial deposit is that extensive coating 
 or layer of sand and gravel indifferently covering 
 all the solid strata, and appears to warrant the 
 opinion of Geologists, that the derivation of this 
 universal stratum may be traced to one great con- 
 vulsion which has ^partly destroyed or broken up 
 the solid strata ; this opinion is further verified, or 
 borne out, in consequence of the gravelly portion of 
 the deposit being in all cases composed of debris of 
 that particular rock most abundant or peculiar to 
 the site. In addition to this, Mr. Conybeare observes, 
 
 * The harbour of Dover is frequently impassable, in consequence 
 of a bar of shingle being formed across the mouth during the preva- 
 lence of south-westerly winds. The immense expense attendant upon 
 the extensive alterations of the works, and the question that arises as 
 to their ultimate efficacy, would lead us to infer that the engineers had 
 overlooked that slow, but certain, operating cause which appears to mock 
 their endeavours, namely, the natural formation of an alluvial dspoxit, 
 on this site.
 
 " that between these accumulations of fragmented 
 rocks and the valleys traversing the present surface 
 of the earth, there clearly exists a close relation ; 
 that, namely, between the breaches that have been 
 opened in the ruined strata, and the materials which 
 have been removed from those breaches. The same 
 causes that have excavated the one have heaped up 
 the other ; and these causes have evidently (as 
 appears from a general examination of the pheno- 
 mena) acted at once on all the strata, and at a period 
 subsequent to their original formation and consoli- 
 dation : hence they must be assigned to the last 
 violent and general catastrophe which the earth's 
 surface has undergone; whatever has occurred since 
 being either the great action of causes still conti- 
 nuing to operate, or convulsions, violent, indeed, but 
 of very limited and local extent." 
 
 The ' regular strata forms the next general 
 division, and is composed of sand, clay, marie, 
 and limestone, &c. The interminable number of 
 beds alternating with each other in the order 
 already represented, would prove a source of infinite 
 perplexity to the geologist as well as the student, 
 were not the general arrangements of the former to 
 comprise the numerous alternating strata of one 
 kind or genus under one comprehensive head, thus : 
 the alternating beds of sand and clay, or chalk and 
 flint, are, however numerous, referable to the ge- 
 neral heads of those two great divisions. The great 
 chalk formation has been with propriety chosen as
 
 the leading feature for the consideration of the 
 geological character of this country : its peculiarity 
 of situation, and the guide that it forms to the 
 observation of other phenomena connected with 
 geological inquiries, have justly rendered this conspi- 
 cuous stratum of first-rate importance in these and 
 similar investigations. One of the most important 
 features of the chalk deposit is that scarcely per- 
 ceptible dipping under all the other strata before 
 mentioned forming, when viewed as one great and 
 comprehensive whole, an extensive hollow or basin,* 
 interrupted only by the line of coast : this formation, 
 consequently, becomes the highest of the English 
 strata, as will appear by referring to what has been 
 already stated when speaking of the " outcrop or 
 basset" of the strata. We have hitherto con- 
 sidered the nature of the strata geologically, and 
 in an extended and general sense. The archi- 
 tect will have to judge of the practical value of his 
 substratum for building purposes, by examining 
 the soil more in detail ; and, indeed, this portion of 
 his labours is arduous and exciting in the extreme ; 
 his excavating operations frequently extending 
 through numerous subordinate strata, in most cases 
 imperfectly consolidated. Other instances occur in 
 which the depth of one stratum (the London-clay, 
 for instance) is of too great a thickness to allow 
 
 The most northerly of these basins, including the metropolis, is 
 on that account called the London Basin.
 
 10 
 
 of its penetration to its entire depth. In order to 
 examine the nature of soils for the purpose of build- 
 ing upon, or for the supply of water, recourse has 
 been had to boring the earth to a considerable 
 depth, thereby enabling us to examine what is 
 brought to the surface by the shell of the boring- 
 rod. The apparatus merits a description in this 
 place, as one of the means, the uses and appliances 
 of which should be distinctly understood by the 
 architect and engineer. The following invention, 
 together with the drawings and description, have 
 been kindly furnished by my esteemed and inge- 
 nious friend, Luke Hebert, Esq., C.E. 
 
 The implements made use of are extremely 
 simple, and may be understood by reference to the 
 above drawings : 
 
 A, is the cross handle of the borer for two men 
 to work. 
 
 B, the chisel borer, which is made to screw 
 into A. 
 
 C, the auger which also screws into A. 
 
 D, a lengthening rod, screws also into A, at 
 one end, and at the other end it has a hollow screw, 
 into which is either fitted the chisel or auger, or 
 another piece of rod. A great number of these 
 lengths of rod are kept generally in readiness, which 
 are screwed one into the other, so as to proceed to 
 the depth of several hundred feet. 
 
 E, a forked iron, used to lay across the hole to
 
 11 
 
 support the rods at the joints, whilst the pieces are 
 being screwed and unscrewed. 
 
 F, a spanner, used to screw on and unscrew the 
 various tools and lengths of rod. 
 
 G, a clearing chisel, with a probe or piercer 
 attached to guide it. 
 
 H, the spring bar used to produce a vibrating, 
 up-and-down motion to the chisel, when used to 
 peck away hard or rocky ground. 
 
 I, iron chain, to connect the cross handle of the 
 tools to the spring bar. 
 
 J, two men at work, boring with the chisel. 
 
 K, the lower pulley of a pair of blocks sus- 
 pended fo compasses above. 
 
 L, the compasses. 
 
 M, winch or crane to work the blocks, when 
 great weights are to be raised. 
 
 O, three lengths of rods, and the chisel in the 
 act of boring perforation, about 42 feet. 
 
 P, spiral worm or auger. 
 
 Q, square iron bar passing through the square 
 tube of the spiral worm. 
 
 R, chains to draw up the spiral worm along 
 the bar. 
 
 S, top plate of spiral worm, to which the chains 
 are affixed. 
 
 T, upper view of plate, showing the square hole 
 through which the bar passes. 
 
 U, angular point of square bar. 
 
 V V, cutting auger edges.
 
 W, underside view of the bottom, cutting parts 
 of the spiral auger. 
 
 As a preparatory measure, a' large circular 
 hole is usually dug to the depth of seven or eight 
 feet, at the bottom of which a floor is formed by 
 means of some planks for the men to work, and 
 pace round upon, whilst using the implements.* 
 If the earth is very soft, the only tool requisite is 
 the auger C, of three to four inches diameter, which 
 is screwed into the cross handle A, and the per- 
 foration is easily effected by the mere turning of it 
 round by two men, as shown in the drawing. When 
 the auger has penetrated to nearly the depth of the 
 tube, it is withdrawn and cleared of its contents ; 
 it is then let down again, and the perforation con- 
 tinued to the length of the instrument. To proceed 
 to a greater depth, the lengthening rods before de- 
 scribed are put into requisition, the auger is detached 
 from the handle by unscrewing it, a piece of rod D, 
 is screwed in its place, and the auger screwed on to 
 the rod. With the instrument thus lengthened seven 
 or eight feet, the boring is renewed by means of the 
 auger as long as the earth is found to be sufficiently 
 soft and yielding : whenever it proves otherwise, or 
 hard and rocky, the auger is detached from the rod, 
 and the chisel B, which is from three to four inches 
 in diameter at its edges, is screwed on in its place. 
 
 * * Instead of this, sometimes a stage is erected, from ten to fourteen 
 feet above the ground, where the men turn the boring implements, 
 assisted by a man or two underneath it.
 
 13 
 
 If the ground is not very hard, the boring may be 
 continued with the chisel, by the workmen pressing 
 upon it as they turn it round ; but when the earth 
 is too hard to be operated upon by the chisel in this 
 way, recourse is had to pecking, which is done by 
 lifting up the implement and striking it against the 
 opposing substance till it is chipped away, or re- 
 duced to powder, to a certain depth. The rod and 
 chisel are then again drawn up, and the auger sub- 
 stituted for the chisel, for the purpose of extracting 
 the pulverized stony matter contained in the hole. 
 The chisel and the auger are thus employed alter- 
 nately where the ground is hard and stony the one 
 for chipping away, or pulverizing, and the other for 
 clearing out. 
 
 As the perforation deepens, the process of 
 pecking becomes very laborious ; recourse is there- 
 fore had to a very simple contrivance, called the 
 spring-bar (see H), which affords the most effectual 
 aid. This is a strong pole, placed horizontally over 
 the well, at the height of three or four feet from the 
 ground, with one end inserted into a spot, or other 
 strong hold. The chain I is attached to this bar, 
 and the handle of the borer is suspended to the hook 
 of the chain, which supports its weight ; a slight 
 vibrating motion is then given to the bar by the 
 workmen, which causes the chisel to peck with great 
 rapidity. 
 
 As the weight of the implements becomes too
 
 14 
 
 great to be drawn up by hand, when the boring has 
 proceeded to a considerable depth, the mechanical aid 
 of a pair of pulley blocks, K, is used for the purpose, 
 which are usually suspended to a tripedal standard 
 (or triangle as it is called), fixed over the hole. In 
 withdrawing the rods for the purpose of bringing 
 up the materials bored through, or for changing 
 the tools, every piece is successively unscrewed, 
 and upon re-introducing it upon the hole, every 
 piece is necessarily screwed on again, which renders 
 the operation exceedingly tedious. This incon- 
 venience, it appears, might be greatly lessened, by 
 erecting a more lofty standard, such as is used in 
 shifting the masts of ships, called compasses, which 
 are formed of two long mast spars, connected to- 
 gether at top with ropes, passing from the summit 
 in a cross direction to the ground (so as to form a 
 quadrangular figure at the base) to secure the com- 
 passes in their position. A crane, or simple winch 
 and ratchet wheel, might then be fixed to one of the 
 legs of the compasses at M, which should work 
 tackle blocks, or a single wheel and axle suspended 
 to the upper part of it ; which would enable the 
 workmen to raise a great length of rod safely, with- 
 out the necessity of the almost incessant screwing 
 and unscrewing, which occupies full three-fourths 
 the time and labour. Considering the compasses as 
 preferable to the tripedal standard, it is here intro- 
 duced in lieu of it ; see L.
 
 In the manner described the boring proceeds, 
 changing the tools to such as may be best suited to 
 cut through the various strata ; whether of a soft, 
 indurated, or stony texture, until the main spring is 
 arrived at, when the water flows up the newly 
 formed tube to the height of the distant spring from 
 which it is derived. If that be at a greater altitude 
 than the surface of the earth bored, the water rises 
 above the ground, producing a perpetual fountain; on 
 the contrary, if it be below the surface, a well must be 
 sunk, of some capacity, lower down than the level of 
 the adjacent spring, into which the water will flow and 
 form a reservoir, to be drawn up by means of a pump. 
 
 The earth is sometimes bored by the before- 
 mentioned simple instrument, to the depth of two, 
 three, or four hundred feet, either for the purpose 
 of obtaining water, or to ascertain the presence of 
 minerals. To carry on the operation of these im- 
 mense depths, it is of course necessary to employ 
 a greater power than that of the two men in the 
 drawing ; but any degree of force may evidently be 
 obtained by lengthening the cross bar or levers, and 
 working them above ground, as a capstan on board 
 a ship ; or a horse may be employed to turn the 
 boring shaft the same as in a mill. These contriv- 
 ances, however, are only suggestions, and must be 
 obvious to every body. 
 
 When the hole is bored, a pipe of cast iron, or 
 other metal, is forced down, to prevent its being
 
 16 
 
 filled up again by the falling in of the surrounding 
 earth, and likewise to keep out the impure land 
 springs, which might taint the water. 
 
 Reflecting upon the excessive labour and te- 
 diousness of the ordinary method of boring the 
 earth, I was led to consider of some means by which 
 the operation might be carried forward at great 
 depths, and the earth be extracted without the 
 necessity of withdrawing the rod, and thus save full 
 nine-tenths of the time and labour, which are occu- 
 pied in the almost perpetual screwing and unscrew- 
 ing of the various pieces composing its length every 
 time it is let down or drawn up. The method by 
 which this desirable object is to be obtained is ex- 
 tremely simple, and may be described as follows : 
 An auger is to be made with a spiral worm, wind- 
 ing round a cylinder, which is to form its centre.* 
 The cylindrical part is not to be solid, but to be 
 perforated throughout its whole length with a square 
 hole of two indies or more diameter, for the pur- 
 pose of receiving within it an iron bar of the same 
 figure and admeasurement. The bar will thus serve 
 the double purpose of a spindle, or shaft, to work 
 the auger, and cause it to bore ; and as a slide, upon 
 which it may be drawn up with facility from very 
 great depths to the surface in a few seconds of time, 
 
 * This figure may perhaps be better understood by comparing it 
 to a circular staircase, winding round, and supported by a column or 
 newell in its centre.
 
 17 
 
 contents be discharged, and let down again, as 
 quickly to proceed in the perforation of a fresh 
 portion of earth. 
 
 It is perhaps worthy of notice, that an auger 
 with a spiral worm is, independently of the other 
 circumstances mentioned, much better adapted to
 
 18 
 
 boring the earth, than the common auger. First, 
 because it requires less power to force the earth up 
 the inclined plane of the spiral auger, than perpendi- 
 cularly up the common auger ; consequently; the 
 latter, by the application of an equal force, cuts its 
 way more slowly. Secondly, because the weight of 
 the earthy contents in the spiral auger, lying sup- 
 ported on its inclined plane, adds force to the 
 cutting, while in the common auger the perpendi- 
 cular column of earth in its centre has a bearing 
 against the edge of it, prejudicial to the cutting. 
 
 That a part of the contents of the spiral auger 
 may not fall out, when being drawn up, the worm 
 or thread is not to be left open, but to have a per- 
 pendicular border, raised upwards at right angles 
 with the plane of the thread as shown in the draw- 
 ing ; the aperture between the upper edge of this 
 border, and the next thread, is left open for clearing 
 out the auger with facility ; see P. The square bar, 
 or spindle of the auger, is shown at Q. E, are the 
 chains attached to the top plate S of the auger, 
 and passing over a pulley. T shows an upper view 
 of the plate of the auger, with the square hole through 
 it. U is the angular point of the bar, which may 
 be formed as a chisel or any other figure. V V are 
 the side cutting edges of the auger. W is an un- 
 derside view of the auger, showing also the two 
 under edges which are connected with those at V V, 
 and form right angles with them. It is evident 
 that various kinds of tools may be ftxed^at the
 
 4 
 
 , I 
 
 
 f" 
 
 
 = F 
 
 
 B 
 
 
 e 
 
 ^ 
 
 
 
 COOOS BORINO APPARATUS
 
 19 
 
 bottom of this auger so as to peck, &c. ; but to go 
 into particulars on these minor points will perhaps 
 be tedious, and extend this description, already, 
 I fear, too lengthy. I must not, however, close 
 it without remarking, that the auger may be 
 easily latched or bolted in its situation, should it be 
 considered requisite, and unfastened on pulling the 
 chains tight ; but I am of opinion, that the weight 
 of the instrument would render the fastening of it 
 down unnecessary, as any required force might be 
 given by loading the upper part. The various 
 figures referred to are fully exhibited in plate 1. 
 
 Considerable ingenuity has been displayed from 
 time to time in the construction of the various im- 
 plements used for boring the earth. The apparatus 
 invented by Mr. John Good is considered efficacious, 
 and possesses an additional advantage in the great 
 simplicity of its construction. The following is a 
 description, from a commuuication furnished by 
 L. Hebert, Esq., of the instruments invented by 
 Mr. Good. The reader is referred to plate 2 for the 
 illustrative drawings. 
 
 It will be noticed that all the instruments, 
 except four, have a screw at their tipper ends, which' 
 are tapped to one thread, so as to fit uniformly into 
 the rod or rods by which the process of boring is 
 conducted. Every rod is screwed in like manner, 
 so that any number of rods may be connected by 
 their screws, end to end, and on the lowermost of 
 the series of rods is fixed the boring implement, 
 c 2
 
 20 
 
 Fig. 1 represents the principal instrument employed 
 for boring through soft earth, such as clay, loam, 
 chalk, &c. : it is of a cylindrical form, with an 
 opening or slit down its whole length, equal in 
 width to one third of the circumference of the 
 cylinder ; this construction having been found by 
 the patentee to be the best suited for earths of a 
 compact .but not very hard nature. When, how- 
 ever, the earth is very soft and yielding, an auger 
 with a narrower slit is provided, only proportioning 
 that part to the degree of tenacity of the earth 
 which is to be extracted. At the bottom of this 
 auger a cutting edge is fixed at a, by screws, and 
 adapted so as to take off and on as may be required, 
 either to change or sharpen the instrument. 
 
 Fig. 2 is an implement of a hollow conical 
 form, with a spiral worm wound round it; which 
 is for the purpose of boring through very loose 
 sandy soils; the sand, as the boring proceeds, 
 passing along the inclined plane of the screw, until 
 it arrives at b, when it is discharged into the hollow 
 receptacle of the core. 
 
 Fig. 3 represents another form of auger, which 
 is employed for extracting mud, sand, and other 
 very soft matter ; it is a close cylinder, with a valve 
 at c, part of the cylinder being broken away to 
 bring it into view. It has a cutting edge, A, at 
 bottom, as Fig. 1, and is employed in like manner: 
 upon turning this auger, the soft, yielding, or fluid 
 matter passes through the valve and fills the cylin-
 
 21 
 
 der, which, on being drawn up, the valve closes, 
 and secures the conveyance of the contents. 
 
 Fig. 4 is a close cylindrical vessel, of the nature 
 of a bucket with a valve at the bottom (as shown). 
 Having "a rope fixed to the upper end, it is dropped 
 down the hole, and, being alternately raised and let 
 fall, it acts as a pump, to extract the liquid or 
 floating matter that may be contained in the hole. 
 Fig. 5 is another pumping tool, more complete 
 than the former ; the cylinder being fitted up in 
 the manner of the common lifting pump with a rod 
 and bucket, e. In this instrument the rod is 
 lifted at every stroke, instead of the whole appa- 
 ratus, as in fig. 4, and has the preference more 
 particularly in great depths. There are two stops 
 and a guide piece at f, to limit the extent of the 
 strokes. 
 
 Fig. 6 is an instrument for extracting rods 
 when broken in the hole : in its upper part it is 
 like a pair of tongs, having at the lower end a 
 cylindrical tube, and above it, at g, a chisel-edged 
 tongue, which is pressed downwards by a spring. 
 Upon lowering this instrument into the hole, the 
 upper end of the broken rod passes through the 
 tube, pressing back the tongue, which holds it fast 
 and prevents its returning, so that it may then be 
 drawn up out of the hole. This last mentioned 
 form of instrument is sometimes employed with two 
 pressing edges or tongues, similar to those shown 
 in fig. 7, at h, which is employed for precisely the 
 same purpose ; the operation and construction of
 
 22 
 
 which will be best understood by referring to the 
 engraved representation. Fig. 8 is another tool for 
 raising broken rods, and adapted so as to lay hold 
 of the rods by means of its chain underneath their 
 joints, and by that means be drawn up. 
 
 Fig. 9 is an improved chisel-punch, employed 
 for perforating stony matter by repeated pecking; 
 the projecting middle piece, which strikes first, the 
 patentee finds to be of great advantage ; the blow 
 is more effectual, and the fractured stone is thereby 
 more easily displaced. Fig. 10 is another form of 
 chisel, for chipping away hard substances, and by 
 its peculiar construction likewise adapted to the 
 operation of boring ; the sides of the instrument 
 are bent in an angular form, so as to present cutting 
 edges, rounding and perfecting the whole as it is 
 turned by the workmen. Its peculiar form is 
 shown by the edge view, Fig. 11, i Fig. 10, and i 
 Fig. 11, representing the same parts. 
 
 Fig. 12 is the apparatus employed for ramming 
 down the iron or other metal tubes which line the 
 perforation after being completed. A block of wood, 
 k, has an iron rod, I, fixed perpendicularly in it ; on 
 this rod a weight, m, is made to travel or slide by a 
 hole being passed through it ; the wooden block 
 being fitted into and over the edge of the upper end 
 of the metal tube, n, the weight is raised by cords, 
 and let fall upon the wooden block, thereby forcing 
 down the pipe. When a piece of tube has thus 
 been driven down even with the surface of the earth, 
 shown at o, another piece is fitted into it, and the
 
 ', 23 
 
 operation of ramming down renewed as before. 
 Another instrument for this purpose is sometimes 
 employed, of the shape of an acorn, shown at Fig. 
 20, which is made to screw into the end of the 
 perforating rods, and being let down into the 
 hole, the lower part of the aCorn tool enters the 
 pipe, and the projecting rim, resting upon the edge 
 of the tube, admits of its being forced down with 
 an even bearing pressure. Fig. 13 is an instru- 
 ment constructed like a pair of tongs, armed at each 
 end with two projecting cutting edges, as at p, which, 
 on being turned round, cut like the sides of an 
 auger or gimblet, and are thus employed in paring 
 or widening the perforation. Fig. 14 is a tool 
 formed like a double bow, employed for pressing out 
 any indentations that may be accidentally made in 
 the lining tubes, wrtich are sometimes made of a soft 
 metal, such as lead, or of a thin substance, such as 
 copper or tinned sheets. Fig. 1& is another tool for 
 the same purpose, forming a quadruple bow ; it is 
 adapted for rubbing down smaller indentations, or to 
 finish the work of the double bow tool. They are 
 both fixed like the other tools by screwing into the 
 end of the rod, or series of rods, and operate by 
 simply turning them round. 
 
 Fig. 16 is a pair of circular clans employed 
 for holding or turning round the tubes when being 
 sunk ; being fastened together by means of screws, 
 the pipe may be firmly held within their grasp. 
 
 Fig. 17 is a tool, of a pine-apple shape, used
 
 24 
 
 for drawing up a piece of tubing when required. 
 It is jagged all over like a rasp, and being 
 struck down forcibly within the tube, it takes fast 
 hold, and allows of its being drawn up. Fig. 1 9 is 
 another implement for effecting the same object; it 
 is a kind of spear with four prongs : being forced 
 down, the points pierce the tube, and enables it to 
 be withdrawn. 
 
 Fig. 18 is a triangular instrument with jagged 
 teeth, used for getting up loose stones which some- 
 times lie in the hole and impede the work: upon 
 being struck down, the stone becomes fixed between 
 the notches of the prongs, and is then extracted. 
 
 At twelve or -more feet from the ground, a 
 stage is erected over the hole. Upon this stage is 
 fixed a double-handed winch, with tackle complete, 
 for two or more men to work, in'raising or lowering 
 the instrument, &c., which becomes of great weight 
 when the perforation has proceeded to a consider- 
 able depth. Between this stage and the ground the 
 men are employed either in turning round the instru- 
 ments in the act of boring (which they do by the 
 assistance of iron levers fastened crosswise to the 
 boring rods by means of screw bolts), in screwing or 
 unscrewing the rods and tools, or in the various other 
 operations before described. 
 
 The examination of the strata may be con- 
 ducted in various ways. The geologist observes the 
 position and quality of the strata, as shown on the 
 surface of the earth, by its " m outcrop or basset," by
 
 25 
 
 the natural sections laid open to his observations 
 in the cliffs of the sea shore, or by descending 
 mines,, quarries, and pits. The architect, it is 
 true, has also these sources of observation at his 
 command; but his investigations must be of a 
 more searching character, and being confined to 
 a certain spot, his proceedings must be modified 
 according to the exigencies of the case. These are 
 neither few nor altogether easy of attainment ; for, 
 although we have observed (p. 6) that " the opera- 
 tions of the architect, in his search after a solid 
 substratum, do not extend to any very great depth," 
 it must be understood, that the observation is applied 
 as a comparison between the excavations necessary 
 for the erection of public works, and the more 
 extensive operations of the same kind that are 
 effected in the mining districts of Europe.* What- 
 
 * The following are the depths of the deepest Shafts in the 
 world : 
 
 Fathoms. Feet. 
 
 1. The shaft called Rochrobichel at the Kitspiiel in the ) 430 2 760 
 
 Tyrol J 
 
 2. A Copper Mine, not now at work, at the Southampton } ** 2226 
 
 Silver Mine at Andreasburg, in the Hartz . . . j 
 
 3. Valenciana Silver Mine at Guanaxuato, Mexico .. . 295 1,770 
 
 Began in 1791, and reached its depth in 1809, 
 when it was stopped by the Revolution ; it is 
 probably the finest in the world, being octan- 
 gular, 30 feet in diameter, and a great part 
 walled with masonry ; expense of sinking esti- 
 mated by Humboldt at 220,000. 
 
 4. Pearce's Shaft at the Consolidated Mines (Copper), I 2 44 1 464 
 
 Cornwall '.......)' 
 
 Not sufficiently productive to repay the draining.
 
 26 
 
 ever may be the depth for the proposed foundation- 
 levels of a building, the scrutiny of the architect or 
 the engineer should in no wise rest there; the 
 stratum which underlies the intended works, is not 
 unfrequently discovered to be of such nature as to 
 subside gradually as the weight is added, carrying 
 with it that portion of the building which stands 
 thereon, together with its artificial foundation. 
 Hence the expedient of boring the earth to ascer- 
 tain the nature and number of the different strata, 
 and, as far as is practicable by such means, to decide 
 upon the quantity of earth to be excavated, and the 
 length of piling" required, should that method be 
 adopted for the construction of the underworks. 
 This preliminary procedure in practical operations 
 is the more essential, as it places us in possession of 
 certain facts and data, relative to the nature of the 
 
 Fathoms. Feet. 
 
 5. Wheal Abraham Copper Mine, Cornwall .... 242 1,452 
 
 6. Dolcoath Copper Mine, Cornwall . 235 1,410 
 
 Produces nearly half the amount of the Conso- 
 lidated. 
 
 7. Ecton Copper Mine, Staffordshire 230 1,380 
 
 Once one of the principal mines in England, hut 
 now inconsiderable. 
 
 8. Woelf s Shaft at the Consolidated ' . -225 1,350 
 
 The bottom of this shaft is nearer the centre of 
 the earth than any other known point. 
 
 The deepest coal Pit near Newcastle is Innou Pit, near } Ig5 99Q 
 
 South Shields, which is > 
 
 Working below the bottom of the pit . . . .-.'..' 12 J 75 
 
 Total . . 177J 1,065
 
 27 
 
 subsoil, without which the necessary examination 
 of the foundation-levels must have been both 
 tedious and expensive. The excavations necessary 
 for building purposes being generally commenced 
 from the surface, and carried on in a vertical di- 
 rection downwards, we must be allowed to consider 
 the chalk stratum as the lowest, in contradistinc- 
 tion to the geological arrangement that places it as 
 the highest stratum, when viewed with reference to 
 its outcropping position. The strata immediately 
 resting upon the chalk basin of London, consists of 
 a series of layers, loose and friable in their tex- 
 tures, namely, white sand, pebbles, marl, and shells ; 
 upon this succeeds the " plastic clay formation," 
 and above this the great formation, called the 
 " London clay." This latter stratum is in some parts 
 immediately under the vegetable soil, and forms the 
 general substratum of the metropolis ; hence its 
 name. As there are certain exceptions respecting 
 the depth at which this stratum first appears, we may 
 observe, that occasionally it is covered with the 
 general diluvial deposit to some considerable depth. 
 The following remarkable instance of the position 
 of the London clay was exhibited in preparing for 
 the reception of the foundations of St. Paul's Ca- 
 thedral. The circumstance being barely mentioned 
 by some, and incorrectly described by other writers, 
 the author submits the following extract from the 
 " Parentalia," as the most authentic description of 
 the proceedings of the architect (Sir C. Wren), in
 
 28 
 
 his search after a solid substratum.* " In the 
 progress of the works of the foundations, the sur- 
 veyor met with one unexpected difficulty : he began 
 to lay the foundations from the west end, and had 
 proceeded successfully through the dome, to the east 
 end, where the brick-earth bottom was very good ; 
 but as he went on to the north-east corner, which 
 was the last, and where nothing was expected to 
 intercept, he fell, in prosecuting the design, upon a 
 pit, where all the pot earth had been robbed-f by the 
 potters of old time. It was no little perplexity to 
 fall into this pit at last ; he wanted but six or seven 
 feet to complete the design, and this fell in the very 
 angle north-east. He knew, very well, that under 
 the layer of pot-earth there was no other good 
 ground till he came to the low-water mark of the 
 Thames, at least forty feet lower; his artificers 
 proposed to him to pile, which he refused : for 
 though piles may last for ever, when always in 
 water (otherwise London Bridge J would fall), yet, 
 if they are driven through dry sand, though some- 
 times moist, they will not. His endeavours were to 
 build for eternity. He, therefore, sunk a pit of 
 about eighteen feet square, wharfing up the 'sand 
 with timber, till he came, forty feet lower, into water 
 and sea-shells, when there was a firm sea-beach ; 
 
 * " Parentalia; or, Memoirs of the Family of Wrens," by Stephen 
 Wren, Son of Sir Christopher Wren ; folio, edit. 1750, p. 286. 
 
 f Taken from, or dug out. 
 
 J In allusion to the old structure, now removed the timber of the 
 piles and the iron shoes at their extremity, were found sound.
 
 29 
 
 which confirmed what was before asserted, that the 
 sea had been, in ages past, where St. Paul's now 
 is. He bored through this beach till he came to the 
 original clay ; being then satisfied, he began from 
 the beach a square pier of good solid masonry, ten 
 feet square, till he came within fifteen feet of the 
 present* ground ; then he turned a short arch un- 
 derground to the former foundation, which was 
 broken off by the untoward accident of the pit." 
 The number of extensive works with which the me- 
 tropolis abounds, and the number of wells, of almost 
 every description of depth, which have been excavated, 
 present us with a mass of information connected with 
 the sections of the strata immediately above the great 
 chalk formation, which is of signal service to the 
 architect and engineer, should his operations occur 
 in the locality of one of these chalk basins. The 
 extreme density of the London clay is shown 
 to afford a highly favourable substratum for the 
 erection of heavy works, where it is not intersected 
 by the river or streams. The plastic clay formation, 
 on the contrary, is exhibited as containing numerous 
 springs, and is altogether of such a nature as to 
 require the adoption of extreme precautionary mea- 
 sures previous to the erection of foundation walls, 
 &c. &c. 
 
 The greater part of the London clay stratum is 
 of one uniform colour, extreme density, and variable 
 thickness. It is so impervious to water, that that 
 necessary article cannot often be obtained until after
 
 30 
 
 the stratum has been perforated to the depth of the 
 plastic clay formation. The inhabitants of London 
 and its vicinity have, however, a resource which 
 forms one of the greatest manufacturing conve- 
 niences of the metropolis. This consists in the im- 
 mense quantities of water held by the alluvium, 
 forming supplies to many of our factories, without 
 the intervention 'of land springs, at a greater depth. 
 Examinations of the strata near London ** have 
 been made by several scientific gentlemen. A few 
 observations made on the subject of the blue clay 
 stratum, by Mr. Parkinson, in a paper published 
 in the " Transactions of the Geological Society," 
 states the depth to be 200 feet in thickness ; f its 
 colour for a few feet in the upper part was observed 
 to be of a yellowish brown, but the remaining por- 
 tion exhibited that dark bluish gray colour which 
 marks its genera. It has been suggested, that the 
 difference of colour remarked between its superior 
 and inferior part arises from a difference in the 
 degree of oxidation of the iron present in it: the 
 result of a more particular examination would ap- 
 pear to justify the supposition, that it arises rather 
 from a difference of quantity, than the degree of 
 oxidation mentioned above ; for " it is probably occa- 
 sioned," observes Mr. Parkinson, " by the washing 
 away of this metal in the water which percolates 
 
 * Transactions of the Geological Society, vol. i. p. 336. " Mr. 
 Parkinson on the Strata and Fossil Remains near London." 
 
 f The particular locality is not mentioned. At Epping, near High 
 Beach, it is about 700 feet in thickness. See Conybeare and Phillips.
 
 31 
 
 through it, and which runs off laterally by the nu- 
 merous drains made near the surface." The fol- 
 lowing sections, afforded by the preparation for the 
 progress of several public works, will further exhi- 
 bit the nature and uniformity of the London strata, 
 and will also serve as a guide to the examination of 
 other strata situated within or near the localities of 
 the several chalk basins. The indentity of strata on 
 the French coast, opposite Dover, with that of our 
 own chalk formation, will be dwelt upon in treating 
 on the Manufacture of Bricks. 
 -'. "' 
 
 SECTIONS OF STRATA 
 
 ABOVE THE CHALK BASIN OF LONDON. 
 
 Names of Works. Depths examined. 
 
 Kr ras H:?e'ct,^- F? 
 
 Authorities consulted. 
 
 sz. i enow ciay, aooiu . 
 3. London clay (hard) 
 
 Thames 
 Tunnel. 
 South Shaft, 
 chiefly in the 
 plastic clay 
 formation. 
 
 Boring at 
 Brentford, 
 near Londpn. 
 
 82 no water 
 
 Feet. In, 
 
 i 1. London clay 90 
 
 i 2. Loose watery sand and grav. 26 8 
 
 3. Blue clay 30 
 
 ) 4. Loam 51 
 
 5. Blue clay with shells, chiefly 
 
 | cythefea 
 
 | 6. Hard conglomerate rock,) 
 
 consisting of flint gravel, > 7 6 
 with a calcareous cement) 
 7. Light blue laminated clay, \. ' 
 S with pyrites J? 
 
 Feet. 
 
 Brick earth . 9 
 Sandy gravel 7 
 Loam ... 5 varies from 1 to 9 feet 
 
 Blue clay 
 
 200 
 
 225 Boringdiscontinued 
 still in clay. 
 
 Seabrook,Esq. 
 
 9 > Conybeare. 
 
 W. Gravatt, 
 Esq. (See 
 Trans, of In- 
 stitution of 
 Civil Engi- 
 neers, vol. i. 
 p. 151.)
 
 Names of Works. Depths examined. Authorities consulted. 
 
 /This Tunnel passes through the plastic"^ 
 Primrose Hill clay formation. The water percolated 
 Tunnel for I . rapidly through the brickwork near the \ r n 
 Birmingham \ entrance (Feb. 1837) ; but the remain- 
 Railway, ing part of the Tunnel is dry and well 
 
 ^ventilated. 
 
 fin the first place, after excavating the 
 upper stratum of gravel and loose soil, 
 four cast-iron curbs were sunk, each 
 six feet long ; the lowest of these en- 
 tered the clay about 3 feet ; the dig- 
 ging was then continued through the 
 
 Particulars of clay to the depth of 140 feet, and a John Donkin 
 a well sunk at curb of brickwork within the iron curb Esq. (See 
 the Excise- j was sunk the whole depth in the ordi- Trans, of In- 
 offlce inBroad A nary way, the iron curb serving merely stitution of 
 Street, Lon- to support the upper stratum, and to Civil Engi- 
 don. prevent the land water getting into the neers, vol. i. 
 
 well. Boring was then resorted to, p. 155.) 
 to the depth of about 20 feet, when 
 the water appeared, and rose to within 
 60 feet of the top of the well ; a copper 
 pipe was then driven through the last 
 mentioned 20 feet, to keep the passage 
 open for the supply. 
 
 Church of St. f This church (Tower) stands upon an^ Paper by Mr. 
 Mary-le-Bow, J ancient concrete causeway 18 feet be- George Gwilt. 
 Cheapside. ( low the present level, which present \ (See " Vetusta 
 (See Engrav- level has been artificially raised during j Monumenta)" 
 ing, Plate 3.) j^the course of some centuries. I
 
 33 
 
 Our observations upon the strata immediately 
 above the chalk need not be extended any further, 
 since from experience and investigation the following 
 facts may be deduced: 1st. That there are only 
 two strata of the series alluded to, which possess the 
 advantage of sufficient consolidation for the support 
 of works of magnitude ; these are the gravel and the 
 London clay. As the thickness of all strata varies 
 considerably, some general rule ought to be adopted 
 for preventing, as much as possible, a premature set- 
 tlement in the intended structure. Referring to the 
 former stratum we may remark, that when there occur 
 a series of thin beds, almost approaching to laminae, 
 they should be wholly discarded, or such means adopted 
 as are hereafter mentioned, to render the substratum 
 of sufficient density for the intended purpose. But 
 when the bed of gravel is consolidated, or partaking 
 of the nature of a conglomerate, and of a thickness 
 equal to the mean distance between the principal 
 points of support, then the foundation may be 
 deemed secure and built upon accordingly. The 
 London clay stratum is so well known to most metro- 
 politan builders and architects, as to need but slight 
 remark from us. Its extreme density and uniformity 
 of character renders it one of the most secure of the 
 natural strata. The extent of its subsidence by 
 compression is trifling, and its thickness for the most 
 part is very considerable. There are, however, certain 
 situations near the banks of the Thames where this 
 stratum exhibits a sudden deficiency of depth, conse-
 
 34 
 
 quently piling has been resorted to in many ex- 
 tensive works in that locality. It will appear 
 obvious that much must be left to the skill and 
 ability of the architect ; his proceedings may have 
 to undergo considerable modifications according 
 to the exigencies of the cases as they occur in 
 practice ; for, although we may cite precedents for 
 professional guidance, it will be necessary, in the 
 first instance, to point out the difficulties that are 
 most likely to beset the practitioner in the course of 
 his operations, and the means best adapted for the 
 successful accomplishment of the end he has in 
 view.
 
 35 
 
 CHAPTER II. 
 
 ON PILE DRIVING AND PILING. 
 
 WITHOUT some artificial means for consolidating 
 loose and friable strata, extensive excavations must 
 frequently be made for works, whose extent and 
 magnitude are not otherwise of sufficient importance 
 to warrant so costly a proceeding. 
 
 On the other hand, where the removal of exten- 
 sive tracts of objectionable strata would be desirable, 
 but is prevented by the interference of some colla- 
 teral cause, then the operation of artificial consolida- 
 tion must be resorted to, either by piling or con- 
 creting the entire surface. The artificial substratum, 
 so frequently met with in the metropolis and its 
 suburbs, technically termed made earth, consists of 
 dry rubbish and refuse, with which deep hollows are 
 refilled ; or otherwise, consist of loose earth, thrown 
 up from the excavations of a contiguous work. 
 Mounds of this kind, or the treacherous surfaces of 
 newly raised ground, are excessively annoying, and, 
 if built upon, require extreme precautionary mea- 
 sures. The foundations of the celebrated Albion 
 Mills, near Blackfriars, were laid upon a substratum 
 of this kind, and afford a good example of the 
 D 2
 
 36 
 
 successful application of scientific resources to a 
 work of considerable magnitude and difficulty. 
 Mr. Farey* thus describes the plan: "The building 
 for the Albion Mills was erected upon a very soft 
 soil, consisting of the made ground at the abutment 
 of Blackfriars Bridge. To avoid the danger of set- 
 tlement in the walls, or the necessity of going to a 
 very unusual depth with the foundations, Mr. Rennie 
 adopted the plan of forming inverted arches upon 
 the ground, over the whole space on which the 
 building was to stand, and for the bottom of the 
 dock. For this purpose the ground upon which all 
 the several walls were to be erected, was rendered as 
 solid as is usual for building, by driving piles where 
 necessary, and then several courses of large flat 
 stones were laid, to form the foundations of the 
 several walls; but to prevent any chance of these 
 foundations being pressed down, in case of the soft 
 earth yielding to the incumbent weight, strong in- 
 verted arches were built upon the ground, bet ween the 
 foundation courses of all the walls, so as to cover the 
 whole surface included between the walls ; and the 
 abutments or springing of the inverted arches 
 being built solid into the lower courses of the 
 foundations, they could not sink, unless all the 
 ground beneath the arches had yielded to com- 
 pression, as well as the ground immediately beneath 
 the foundation of the walls. By this method the 
 foundations of all the walls were joined together, so 
 
 Treatise on the Steam Engine, by John Farey, p. 515.
 
 37 
 
 as to form one immense base, which would have 
 been very capable of bearing the required weight, 
 even if the ground had been of the consistency of 
 mud, for the whole building would have floated 
 upon it, as a ship floats in water; and whatever 
 sinking might have taken place, would have affected 
 the whole building equally, so as to have avoided 
 any partial depressions or derangements of the walls ; 
 but the ground being made tolerably hard in addi- 
 tion to this expedient of augmenting the bases by 
 inverted arches, the building stood quite firm." 
 
 Notwithstanding the considerable density ex- 
 hibited by the London clay, such density is by no 
 means invariable. The sandy, loose, and muddy 
 layers, which occasionally intervene throughout this 
 formation, have been repeatedly met with, and caused 
 considerable annoyance and interruption in the pro- 
 secution of works that required extensive excavating 
 operations. The excavations of the Albion Mills, the 
 Highgate Tunnel, the Thames Tunnel, the Catherine 
 Docks, and many other public works in this metro- 
 polis, have proved to be so many exceptions to the 
 invariable density of the London clay. It must be evi- 
 dent, therefore, that piling is of necessity resorted to in 
 those instances where the thickness of the loose stratum 
 is too great to admit of a denuding operation being 
 effected. There is another circumstance which merits 
 particular notice as connected with the foundations of 
 buildings upon the clay. This is, the sudden shelving 
 or thinning of thestratumnearthebanksof the Thames
 
 38 
 
 on the Kentish or Surrey shore. The perforation of a 
 few feet from the surface enables us to pierce through 
 the London clay, and enter the next formation, called 
 the plastic clay. Now the nature of this latter stratum 
 is frequently such as to yield considerably, with the 
 addition of a moderate weight placed upon its surface. 
 Its depth being considerable, piling is not always 
 advantageous, as, on the one hand, the density of the 
 soil will not admit of sufficient fraction on the sides 
 of the piles, and on the other, the depth being too 
 great for the feet or pointed ends of the piles to 
 pierce entirely through and rest upon the chalk. In 
 a case of this kind, therefore, a concretion of the 
 entire surface is, perhaps, the most secure artificial 
 substratum. Buildings may, however, be erected 
 upon a yielding soil when certain means are taken 
 for their proper equilibration, as is shown in the 
 example of the Albion Mills. Piles and piling are 
 of various denominations. The square pile, for 
 heavy works, consists of a long piece (or stick, as it 
 is technically termed) of timber, roughly squared, 
 bound at the upper end with a hoop of iron to 
 prevent its splitting from the blows of the ram, 
 and protected at the lower extremity with iron 
 shoes forged to the shape required, in order that 
 the pile may be driven with greater certainty, and 
 through any obstacle that may obstruct its pro- 
 gress downwards. Previous to entering upon an 
 investigation of the nature of piling, we shall 
 direct the attention of the reader to the various
 
 39 
 
 machines used for the purpose of driving piles into 
 the ground. The old pile machine represented in 
 the annexed figure, is composed of two upright 
 
 i 
 
 grooved posts B, supported by side braces G G, 
 fixed upon the sole F, and attached to the back stay 
 E ; this is connected above to the two uprights, and 
 below to the forked framing H, also secured to the 
 sole F. The ladder for mounting to the top of the 
 machine is shown on the back stay E. The ram A,
 
 40 
 
 destined to drive the pile D, is, in this instance, 
 supposed to be a large block of well-seasoned wood, 
 firmly bound with iron, top and bottom, to prevent 
 it from splitting. It has two tenons or ears stopped 
 with keys, driven in behind, for the purpose of keep- 
 ing it between the grooved posts. There is also 
 a ring to receive a hook K fastened to two cords, 
 each passing over a pulley placed at the top of 
 the two uprights. The weight of a wooden ram 
 is generally about 800 Ibs., so that the effectual 
 working of this machine would require at least 
 a gang of twenty men, whose exertions, indivi- 
 dually considered, would represent a very effective 
 force, but, collectively employed upon the machine 
 we have represented, will show a very serious loss of 
 power, considering the means employed. In order 
 to ascertain the defects of this pile-engine, it will be 
 necessary to examine the manner in which the com- 
 bined energies of the workmen are directed to pro- 
 duce the action of the ram. The arrangement of 
 this machine is that of a cord passing over a fixed 
 pulley. The tension of the cord being uniform 
 throughout its length, it follows, that in an applica- 
 tion of this kind the power and weight are equal. 
 For the weight stretches that part of the cord which 
 is between the weight and pulley, and the power 
 stretches that part between the power and the pulley. 
 And since the tension throughout the whole length is 
 the same, the weight must be equal to the power.* 
 
 * Lardner. -,.-, ,-;,,
 
 41 
 
 Theoretically considered, we obtain no me- 
 chanical advantage by this use of the pulley, but in 
 its practical applications we are enabled to give to 
 the moving power a more advantageous direction, 
 and with greater facility than without such adventi- 
 tious aid. Muscular energy may therefore be exerted 
 variously by the means already described. By mus- 
 cular exertion a man may so far overcome the 
 resistance as to raise his own weight: but in ordinary 
 cases, in raising the arms to lay hold of the cord, 
 and then bending himself as low as is convenient, he 
 can scarcely raise above 70 Ibs. ; which is about 
 half the weight of his body, commonly estimated 
 at 140 Ibs. We have supposed the cord to be drawn 
 vertically ; for if it was drawn sideways, the weight 
 or force applied to it would decrease as the obliquity 
 increases. To apply this reasoning to the machine 
 in question, we are to consider that the ten men 
 who are exerting their powers at the ends of the 
 cords attached to the main ropes I L, can only 
 draw obliquely to the vertical line I N, and the 
 same also with respect to the main ropes, I L; 
 since in both cases they form a circle, in which 
 those who are opposite to the others destroy reci- 
 procally a part of their power, which is here an 
 inevitable defect, since it is necessary that the 
 ten men should be placed around the machine 
 in order to act together. It is not the same with 
 the obliquity I L; this may be applied in a more 
 vertical direction, by passing the cord MIL over a 
 wheel, 4 or 5 feet in diameter, instead of the pulley,
 
 42 
 
 which seldom exceeds 10 or 1 1 inches. The improve- 
 ment effected by the use of the wheel experience 
 has fully confirmed; sixteen men being enabled 
 thereby to effect the work of twenty men by the 
 former method. It remains now to be shown in 
 what manner the machine is to be constructed, to 
 supersede the use of the pulley. By referring to 
 figs. 1 and 2 will be seen the plan and side elevation 
 
 FIG. 1. 
 
 FIG. 2. 
 
 of the apparatus. To render the pile-machine sus- 
 ceptible of the preceding advantages, it is only 
 necessary to modify the top part of the machine. 
 A marks the two grooved uprights, crowned with a 
 cap B ; each of the posts is connected with a piece 
 placed horizontally 3 feet under the cap B ; these 
 pieces are fastened together with a cross-quarter 
 of timber, supported by the back stay G, which 
 is fixed in such manner as not to obstruct the posi- 
 tion of the wheel E F, which has its nave pierced 
 with a square iron, from which the axle projects, 
 and rests upon its bearings D. A steadier action 
 and greater solidity is gained by this method than 
 if they were not united with the square iron inserted
 
 43 
 
 into the nave of the wheel. The wheel is supposed 
 to be 4 feet 6 inches in diameter, measuring from 
 the rope channel, and distant from the posts A, about 
 3 feet. This arrangement enables the men to ope- 
 rate with greater facility, having more room for 
 placing themselves around, and enabling them to 
 pull in a more vertical direction at the other end 
 E H ; the more so, as the back stay and ladder G 
 not being in the way, the sixteen men are employed 
 in pulling only one rope, and not divided into two 
 separate gangs the action in the fetter case never 
 being perfectly alike. Another advantage to be 
 derived from the use of the wheel is, that there is 
 only one movement required to counterpoise it, 
 namely, about one-third of the circumference of 
 the wheel for each blow it becoming greater by 
 the acceleration that the ram acquires. The pulley, 
 on the contrary, in consequence of the smallness of 
 its diameter, makes nearly two revolutions when the 
 ram rises or falls, thereby causing additional resist- 
 ance by the stiffness of the cords. In conclusion, we 
 may remark, that, rude as the present contrivance 
 may appear, a pile may be driven by it with great 
 expedition, as it is effected by a series of smart 
 shocks given in succession. The workmen should, 
 however, take advantage of the rebounding of the 
 ram by pulling immediately that effect takes place ; 
 much labour may be saved by attention to this point. 
 The advantage of this form in isolated situations is 
 obvious. A workman, unaccustomed to the arrange- 
 ments of machinery, may in a few hours construct a
 
 44 
 
 powerful machine like the one represented. By in- 
 clining the grooved upright posts (technically termed 
 shears) the machine may be altered for the purpose 
 of driving piles in inclined positions for embank- 
 ments, abutments, &c. It must at the same time be 
 distinctly understood, that it will not bear to be 
 brought into competition with the machines now 
 in general use, where two men, with the aid of 
 a wheel and pinion, will effectually perform the 
 driving of larger piles that would require sixteen 
 men using the one described, and for which 
 the above calculations have been made. Figs. 3 
 and 4 are further improvements on the ordinary 
 machine, and are intended for raising a weight 
 or ram 12 or 1500 Ibs. by the action of three 
 or four men applied to the windlass A, fig. 3, or 
 the capstan B, fig. 4. It is evident that longer time 
 is required for working this machine, but the force 
 is considerably greater: therefore machines com- 
 bining this arrangement are more generally em- 
 ployed for heavy works, such as bridges, &c. The 
 power, however, is far from being applied in a 
 vertical direction ; and time is also lost in releasing 
 the hook C from the weight E, as well as in re- 
 placing it after the ram has descended. The ad- 
 vantages of fig. 3 chiefly consist in its capability of 
 being used for driving piles in angles, as well as the 
 addition of the hook C for releasing the ram by 
 pulling the rope F, which could not otherwise be 
 accomplished. When piles are driven in rows fig. 4 
 is more convenient, as it admits of being easily
 
 FIG. 3. 
 
 FIG. 4.
 
 46 
 
 removed from place to place. The shears are 
 placed in the centre of the triangular framing. 
 Fig. 3 has no shears, but simply an upright post. 
 The ram slides on this, and is guided by two pieces 
 of bent iron, or ears, instead of the grooves. Piles 
 driven in horizbntal positions are either driven by 
 an engine similar to a battering-ram, or, according 
 to Belidor, by slinging ropes round a long and 
 heavy piece of timber, and throwing it forward by 
 the united power of six or eight men against the 
 head of the pile. 
 
 The successive additions and improvements 
 effected in the construction of the pile-engine were 
 the pincers or tongs, under several modifications; 
 followed by the engines of Valone and Bunce. A 
 
 FIG. 5. 
 
 FIG. 6.
 
 47 
 
 further improvement on the last-mentioned machine 
 has left the pile-engine in that state of perfection in 
 which we now find it. Its simplicity and efficacy are 
 such, that it has nearly superseded all others, and 
 is the modification now universally employed in 
 large works where piling is required. Figs. 5 and 6 
 represent the improved pile-engine. 
 
 A A are the grooved upright posts, having 
 pieces bolted on, forming the grooves for the cast- 
 iron ram B B to slide in. Two men working at 
 the handles E E cause the drum to revolve, round 
 which the rope coils. The motion of the drum is 
 communicated by a pinion fixed on the axle of the 
 fly-wheel F, and takes into a toothed wheel placed 
 on the axle of the drum. On this axle also is a 
 ratchet and pall, to prevent the ram falling should 
 the workmen leave the engine. The pincers A A 
 and D D (figs 7 and 8) are fixed to a block of 
 
 wood, C C, (same as fig. 8) called the follower,
 
 48 
 
 sliding in the same grooves with the ram. The 
 rope is fixed to the iron B B (figs. 7 and 8) in the 
 centre of the follower. Now, the ram being raised, 
 the ends of the pincers will pass between the 
 inclined planes D, at the top of the engine (fig. 6), 
 and by compressing the top of the tongs will open 
 the lower ends of them, which clip a ring on the 
 top of the ram, and consequently liberate the weight 
 and allow it to fall on the head of the pile. The 
 pall is then released from the ratchet, and the tongs 
 and follower slide down and again lay hold of 
 the ring on the top of the ram D (fig. 7). Occa- 
 sionally the tongs are made with rollers, A A 
 (fig. 8), on the ends, in order that they may pass 
 with greater ease between the inclined planes. 
 When the tongs were first introduced, a strong 
 spring was fixed upon one of the levers to keep 
 them closed when they had taken their hold of the 
 ram. This is now discontinued ; for, if made with 
 sufficient weight of metal, they will hold with equal 
 security. 
 
 To estimate the power of these machines we 
 must multiply the weight raised into the velocity it 
 acquires in falling. 
 
 Let w weight of ram 
 
 v = velocity of feet per second 
 Then w -f- v = momentum of stroke upon the head of the pile. 
 
 As per example, let us suppose the weight of the 
 ram = 800 Ibs., and the height fallen through in one 
 second of time = 16 feet,* then 800 + 16 = 12- 
 
 * See Law of Falling Bodies.
 
 49 
 
 800, the force with which the pile is struck by the 
 ram. If pulleys or a windlass be employed to raise 
 the weight to a considerable height and then sud- 
 denly disengage it, and the momentum of the 
 stroke will be as. the square root of the space fallen 
 through. The inductive reasoning on this subject 
 by an intelligent Engineer (Mr. NICHOLSON) is thus 
 explained : " Notwithstanding the momentum or 
 force of a body in motion is as^ the weight multi- 
 plied by the velocity, or simply as its vetocity when 
 the weight is given, or constant ; yet the effect of 
 the blow will be nearly as the square of that 
 velocity, the effect being the quantity the pile is 
 driven into the ground by the stroke. For the 
 force of the blow, transferred to the pile, being 
 destroyed in some, certain definite time by the 
 friction of the part within the earth, which is nearly 
 a constant quantity, and the spaces in constant 
 forces being as the squares of the velocities, or, 
 which is the same thing, nearly as the height fallen 
 by the ram to head of the pile." 
 
 The following formula is employed by an 
 eminent Engineer for the purpose of ascertaining 
 the resistance of a driving or driven pile : 
 
 Let w = Weight of ram i _ 
 
 _. ., .. f In Cwts. 
 
 p = Ditto of pile ) 
 
 h = Height fallen through by ram, in inches. 
 d = Descent of pile by one blow of ram. 
 
 Then w. JP ) 
 
 C = The weight which will just sink the pile. 
 
 dtw+p) 
 
 Having now minutely examined the mecha- 
 E
 
 50 
 
 nical construction and practical effects of these 
 machines, we proceed with our inquiry relative to 
 the degree of security afforded to the foundations of 
 buildings by the application of piling. We esteem 
 the opinion of those men whose genius, talents, and 
 industry, aided by extensive practice, have con- 
 tributed so powerfully to raise architecture to its 
 distinguished position in the rank of sciences ; and 
 upon the authority^ of one* (corroborated by the 
 experience of ages) who stood proudly pre-eminent 
 in mathematical skill, and its application to the 
 above noble purposes, do we affirm, that the dura- 
 bility of piling, when properly employed, will 
 outlast the durability of the superstructure itself. 
 The premature decay that has occasionally occurred 
 to the piling employed im many extensive works, 
 has not arisen, in any instance, from the inefficiency 
 of the material employed that is, when the ma- 
 terial (timber) has been selected from among the 
 best of its kind. A sine qua non with us in the 
 judicious application of piling, is the most complete 
 and perfect imbedding of the piles in the sub- 
 stratum ; and also, the most effectual covering of 
 their surface, by the masonry or other material 
 being perfect in-bed, and well flushed with the 
 mortar or other cement employed. Alternating 
 exposures to heat and cold, dry and moist, together 
 with the never-failing destructive effects of that 
 * 
 
 , * Sir Christopher Wren.
 
 51 
 
 most powerful of all menstruums, the atmosphere, 
 are among the real and most active enemies of 
 piling operations. Another and no less insidious 
 enemy exists in the " pile worm ;" a creature that 
 resolutely attacks the timbers, and speedily destroys 
 them. A few years since the Author had an 
 opportunity of examining the remains of some 
 piling which had been destroyed by them : the piling 
 was completely riddled with holes, and the interstices 
 partially filled with sea-sand. The dikes of Holland 
 have suffered severely from their ravages; but a 
 method has been devised* for the protection of the 
 piling, and appears to answer tolerably well. In 
 this country Kyanised timber (as it is termed) has 
 been extensively employed, and its beneficial effects, 
 as a remedy for the dry-rot, have been most satis- 
 factorily proved 1 . 
 
 The most important applications of piling to 
 the purposes of architectural construction may ^ 
 classified under the following heads : 1st. Of piling 
 for the foundations of bridge and other piers. 2nd. 
 The application of piling to river, wharf, and em- 
 bankment or retaining walls, including the varieties 
 of close, grooved, plank, and inclined piling. The 
 practice of piling for the support of such a cumbrous 
 mass of materials as the bearing piers of a bridge, 
 has been most generally observedj and is generally 
 found to be adequate to the purpose. To confirm 
 these observations, we shall instance at least three 
 
 See Philos. Trans., No. 455, Sect. 5. 
 E2
 
 52 
 
 important desiderata that are attained by a judicious 
 application of piling: 1st. As a convenient and 
 secure method of passing through a loose soil to one 
 of sufficient density for the support of great masses 
 of weighty materials. 2nd. As a powerful assistant 
 in consolidating loose or wet soil to a considerable 
 depth. And, lastly, piling may be properly con- 
 sidered as the insertion of a firm strata opposed to 
 an inferior one, by being placed at right angles to it. 
 The piling and interstices between the pile, taken 
 collectively, may be considered as a solid mass, 
 whose friction against the sides of the surrounding 
 earth will have a hold upon the soil, at least in 
 proportion to its actual superficies. In a tenacious 
 or compressed soil the amount of friction is the 
 same for a single pile, fully demonstrating the 
 security of this application of timber 1 to the purposes 
 of a most important branch of construction. The 
 %pimdations of the bearing piers of Southwark iron 
 bridge exhibit a very favourable illustration of the 
 application of piling to pontile architecture. (See 
 plate 2.) The piers were surrounded with a coffer- 
 dam, constructed with three rows of piles of whole 
 timber, enclosing a space elliptical on the plan. 
 Each pier rests upon a massive timber platform, 
 supported by piles ; close to the outer edge of the 
 offsets of the pier a row of timber sheeting piles 
 were driven : this uniform belt of timber forms as 
 it were a close stationary dam, preventing the 
 substratum upon which the piles rest from being
 
 SOUTHWARK IRON BRIOCE PtERS.
 
 58 
 
 pressed outwards by the weight of the pier ; a, cir- 
 cumstance that frequently takes place where piling is 
 employed, and the work heavy. This circumstance is 
 well known to miners, and may be thus described : 
 If a level (in a mine) be driven one or two hundred 
 yards underground through the solid rock, there 
 will be no danger of its not continuing entire for an 
 indefinite length of time ; but if the sides and roof 
 only of the level be formed in the rock, and the 
 bottom be cut through into a bed or substratum of 
 clay, however strong and stubborn it may be, being 
 pressed by the weight of the superincumbent rocks, 
 it will by slow degrees swell and rise up in the level ; 
 and, unless it be continually pared down or pre- 
 vented by some means, the level will, in no great 
 length of time, be entirely choked up.* In tunnel- 
 ling operations this tendency of the soft stratum to 
 swell and rise up is effectually counteracted by the 
 inverted arch formed under the roadway of the 
 tunnel. The Blis worth cutting on the Birmingham 
 line of railway also exhibits an example of the 
 inverted arch, adopted as a precautionary measure 
 against the rising of the soil. In the latter work 
 this mode of proceeding became the more necessary, 
 as the rocky stratum through which the cutting passes 
 was underset or supported by retaining walls, in con- 
 sequence of the intervention of the weald clay\ which 
 underlies the rocky stratum. Close piling is executed 
 
 * Seaward on the rebuilding of London Bridge. 
 t This stratum is subject toslips, carrying with it the superincumbent 
 stratum. The presence of moisture in this clay converts it into mud.
 
 4 
 
 by driving two piles at a distance apart ; these are 
 connected together by bolting pieces of timber to 
 them longitudinally, technically termed wailing- 
 pieces. Grooved and plank piling is executed by 
 grooving the piles, and introducing the edge of a 
 plank of timber into the grooves. This latter 
 description of piling is more frequently employed in 
 the construction of coffer-dams, as it generally super- 
 sedes the necessity of puddling the joints with clay ; 
 grooved piling is, however, very liable to disarrange- 
 ment. When the pier is completed (in bridge build- 
 ing), the piles forming the damare with drawn. The 
 timber generally employed is either oak, elm, or 
 beech. The coffer-dams of the new London Bridge 
 were of an elliptical form, and consisted of three 
 rows of piles dressed in the joints, without grooving ; 
 some of them measured between eighty and ninety 
 feet : they were all puddled with clay, and shod 
 with iron. 
 
 The foundations of the piers are raised upon 
 piles of beech wood, on the heads of which were 
 laid two rows of sleepers, 12+12 inches, covered 
 with level planking, six inches in thickness. 
 Occasionally a strong grating of timber is laid, 
 and between the openings or chequer- work of the 
 framing the piles are inserted, and driven. Border 
 piling is also driven round the exterior of this 
 grating. An essential precaution is necessary in 
 commencing the piling in this instance; 'namely, 
 by driving the first piles in the centre of the 
 framing, and proceeding with the work outwards,
 
 55 
 
 to prevent the earth becoming too compressed 
 in the centre ; which would be the case if the 
 piling was commenced at the outer row of interstices, 
 or on the border of the grating. 
 
 In some situations, the grating of timber, is 
 covered with thick planking, and the pier is built 
 upon it, without piling. 
 
 In coffer-dams the larger piles face the water, 
 and the double or triple rows are of smaller scant- 
 ling. Plank or other piling driven obliquely into the 
 earth is only bevelled on one side of the lower end ; 
 and such piles, if of small scantling, are charred on 
 their extremities, instead of being shod with iron. 
 The thickness of short piles may be allowed = -^ 
 of their length ; but for long piles the average dia- 
 meter is 14 inches. Plank piles are from 3 to 5 
 inches thick, according to their lengths. It is 
 a fact worthy of observation, that some failures 
 have occurred in buildings of magnitude, in con- 
 sequence of the premature destruction and decay of 
 their artificial foundations, and not from a subsidence 
 of the soil ; it therefore becomes a highly import- 
 ant consideration to trace the causes originating 
 these destructive effects, and to suggest such re- 
 medies as appear to us based upon a philosophical 
 and scientific view of 'the subject. The most perni- 
 cious effects have hitherto resulted from a practice 
 which, by force of example alone, has gained 
 considerable ascendancy ; we allude to the practice 
 of raising the superstructure upon planking, or balks
 
 56 
 
 of timber laid flat upon the soil, without any further 
 preparation than the mere levelling and ramming o 
 the ground. 
 
 As the proximate cause of most failures is sup- 
 posed to arise from the subsidence of the substratum, 
 the intervention of an artificial stratum of greater 
 density is the most obvious means to remedy this de- 
 fect. It is probable, therefore, that a stratum of sound 
 timber laid horizontally was supposed to meet the 
 difficulties of the case. Upon a slight consideration, 
 it will be* perceived that a more unscientific plan 
 could not well have been adopted. In the employ- 
 ment of timber for the purpose of receiving or 
 counteracting the effects of heavy strains, the force 
 should be directed in such a manner as to cause 
 compression of the fibres at the extremities of those 
 fibres, or an extension of them by causing the force 
 or thrust to be exerted in the direction of their 
 length. A longitudinal framework of timber, laid 
 horizontally and subjected to an enormous pressure 
 by the weight of the superincumbent materials, will 
 so far compress the fibres of the materials in the 
 direction of their breadth, as to cause a serious and 
 alarming disturbance in the equilibrium of the 
 building ; and eventually to ensure its destruction. 
 The extensive settlements of the store-houses at 
 .Chatham and Woolwich, have, in a great measure, 
 arisen from this reprehensible mode of construction. 
 With a view to show the enormous weight that 
 timber will bear when used as vertical columns or
 
 57 
 
 prisms, we here subjoin the crushing weight of 
 different species of timber, deduced from an ex- 
 tensive set of experiments made by the late Mr. 
 Rennie. 
 
 Ibs. 
 
 Elm ~\ s 1284 ^ 
 
 White deal S Cubes of one inch < 1928 f Crushing weight. 
 English oak > C 3860 > 
 
 Prisms of seasoned oak two inches square, and 
 in height two, four, and six feet, were crushed by 
 vertical pressures of 17,500, 10,500, and 7,000 Ibs. 
 If four inches square, and of the same altitudes, 
 the following loads were required to crush them; 
 namely, 80,000, 70,000, and 50,000 Ibs. Another 
 vital objection to the practice of planking, &c., 
 is, that a great portion of the timber remains 
 exposed to the action of alternate damps, and the 
 corresponding destructive influence of the atmo- 
 sphere. Light sandy soils, in low situations and 
 near large rivers, are particularly subject to the 
 influence of the tides ; filtrating upwards- with the 
 flux, and again becoming dry with the reflux : con- 
 sequently the timbers are alternately subjected to 
 dryness and moisture, by being placed on the 
 surface of the ground, instead of being buried be- 
 neath it. On a clay soil the evil is not of less 
 magnitude. JUie retentive nature of the clay will 
 continually expose a wet surface to the underside of 
 the timber, while the other surfaces will remain in 
 various states and temperatures : decay rapidly 
 ensues, and the building fails, by the premature
 
 58 
 
 destruction of the very means adopted for its pre- 
 servation. While we justly condemn this mode of 
 building, on defect of principle, we are bound to 
 mention that there is every reason to hope that the 
 preservation of timber from the premature effects of 
 the rot has at length been effectually accomplished. 
 To counteract the destructive influence of the 
 atmosphere, and to secure timber from the effects 
 resulting from exposed situations, has occupied the 
 attention of the scientific experimentalist for a long 
 succession of years. The antiseptic qualities of 
 coal-tar have been long known, and in many in- 
 stances, where perseveringly applied, have been pro- 
 ductive of considerable benefit. Although the 
 recent invention of Mr. Kyan would appear to 
 leave nothing to be desired, yet there are still many 
 who place considerable" reliance on the former me- 
 thod of preserving wood and metal. The simplicity 
 of the operation, and the cheapness of the materials 
 employed, are urged as additional recommendations 
 to the use of the anti-corrosive composition. In the 
 year 1822, Mr. John Oxford procured letters patent 
 for an improved method of preventing " Decay in 
 Timber, Metallic Substances, and Canvass, &c." 
 This was proposed to be accomplished by the fol- 
 lowing method : The essential oil *>f. the tar is 
 first extracted by distillation, and at the same time 
 saturated with chlorine gas. Certain proportions* 
 of oxide of lead, carbonate of lime, and carbon of 
 
 * See specification in the Repository of Arts, Vol. Ixiii., N. S.
 
 59 
 
 purified coal -tar, are well ground, and mixed with 
 the oil ; the composition is then applied in thick 
 coatings to the substances intended to be preserved. 
 The penetrative qualities of this compound are con- 
 siderable, and may be employed with advantage in 
 many cases. An American patent has very recently 
 been granted for a similar purpose ; and the ingre- 
 dients of the antiseptic fluid are nearly identical 
 with those already described ; the metallic oxide, 
 however, consists of iron. Since the year 1812, a 
 gentleman of the name of Kyan prosecuted an 
 immense number of experiments on the preserva- 
 tion of timber ; and et at length ascertained that 
 albumen was the primary cause of putrefactive fer- 
 mentation, and, subsequently, of the decomposition 
 of vegetable matter." The affinity of corrosive 
 sublimate for this material was not unknown ; but 
 the credit is due to Mr. Kyan for successfully 
 following up by a well-conducted series of experi- 
 ments, and .ultimately deciding in a most satisfactory 
 manner, that vegetable matter may, by saturation 
 with the bichloride of mercury, be effectually made 
 to resist the effects of putrescent fermentation. 
 This, therefore, forms the basis of an invention* 
 which is likely to prove, above all others of a 
 similar kind, a most powerful agent for the inde- 
 finite preservation of a great variety of vegetable 
 substances. Its application to the preservation of 
 
 * Now in the hands of a respectable company, called " The Anti 
 Dry Rot Company."
 
 60 
 
 timber may justly be ranked among the most 
 important benefits conferred upon society by the 
 hand of science. The application of iron for the 
 purpose of piling has recently been adopted in some 
 situations that are likely to prove severe tests of its 
 applicability, and, if successful, to warrant a more 
 extended use of this material in a variety of situa- 
 tions where timber piling might be considered 
 objectionable from its exposed position. In an 
 admirable memoir on the subject of iron piling, 
 published in the first volume of the " Transactions 
 of the Institution of Civil Engineers," it is therein 
 stated, that the introduction of metal for the purpose 
 of piling originated with Mr. Mathews, of Brid- 
 lington, previous to the year 1822. A gentleman of 
 the name of Ewart (now of Her Majesty's Dock 
 Yard at Woolwich) secured by patent, in 1822, a 
 plan for the construction of iron piling, applicable 
 to the formation of coffer-dams. It appears that this 
 invention was not originally contemplated for the 
 purposes of permanent piling ; notwithstanding 
 which, subsequent adaptations to the latter purpose 
 lead us to infer that they are all derivable from the 
 mechanical arrangement exhibited in the plans of 
 Messrs. Mathews and Ewart. The priority of in- 
 vention, however, is most justly due to the former 
 gentleman; Mr. Ewart having matured his invention 
 without a previous knowledge of the proceedings of 
 Mr. Mathews. 
 
 Mr. Ewart's plan has been most successfully
 
 Ji, metier Fig; 
 
 IRON PILING.
 
 61 
 
 carried into execution, under the able direction 
 of Mr. Milne, the Engineer of the New River 
 Company, at Broken Wharf, and by Mr. Hartly, 
 of the Liverpool Docks, at the basin of George's 
 Dock at Liverpool. A detailed illustration of the 
 construction of the piling is shown in plate 3,* 
 which is fully explained in the accompanying 
 reference to the various figures. Fig. 1 is a plan 
 of three metal piles, united together by cramps of 
 cast-iron. The cramps B are made to fit and slide 
 easily on the dovetailed ribs or ledges a, when the 
 piles are placed side by side, yet sufficiently dove- 
 tailed to retain the piles or plates in their proper 
 situations in relation to the cramps. Fig. 2 is a 
 plan of the heads or upper parts of the piles, 
 and cross sections of the cramps for securing 
 them at their vertical joinings. Fig. 3 is a back 
 elevation of the piles as seen in the inside of the 
 coffer-dam, showing also the horizontal joinings 
 where additional lengths of piles are required. 
 Fig. 4 is an end view of one portion of a pile, 
 detached at the horizontal joint. Figs. 5 and 6 
 are views of the cramp and wedge for securing the 
 piles at their joints. Fig. 7 is a side view of one of 
 the vertical cramps B. Fig. 8 is a view of that 
 part of the same cramp which is applied next to the 
 piles. Fig. 9 is a cross section of the lower part of 
 the same cramp, through the line op. Fig. 10 is a 
 horizontal plan, of the form of a coffer-dam, for the 
 
 * Collated principally from the Specifications given in the 43rd 
 volume of the Repertory of Patent Inventions.
 
 62 
 
 foundation of a pier. Fig. 1 1 is a plan of part of 
 a coffer-dam, showing how the piles are arranged 
 round it. Fig. 12 is an end view or elevation of 
 part of the same. Fig. 13 is a plan of three piles, 
 the middle one being curved to admit of expansion 
 and contraction in the line of piles on each side of 
 it. Fig. 14 is a horizontal section of two cast-metal 
 piles, united at their vertical joints by cramps cast 
 in one piece with the piles. 'Fig. 15 is a horizontal 
 section of three piles of wrought-iron, united at 
 their vertical joints by cramps of wrought-iron 
 or cast-metal. The patentee states, in his speci- 
 fication, that the piles are made in portions of 
 various lengths, generally from 10 to 15 feet, but 
 shorter or longer when required. The vertical 
 cramps are also made of various lengths, corre- 
 sponding to the lengths of the piles, along which 
 they are continued from top to bottom ; but so that 
 the joints of the cramps, end to end, shall never be 
 in the same horizontal line with the joints of the 
 piles which they connect. When necessary, these 
 cramps are strengthened by making them thicker 
 than shown in the drawings, or by adding a rib to 
 them as represented at c, Fig. 1. The construction 
 of this kind of piling has been successfully modified 
 in its application to various works, by Messrs. 
 Walker, Cubitt, Sibley, and others ; the plan de- 
 vised by Mr. Sibley exhibits the greatest deviation 
 from the original idea ; and, in fact, may be almost 
 considered as a distinct invention. These piles were 
 made hollow, and when driven, were filled with
 
 63 
 
 concrete. With respect to the effect produced by 
 the pile-engine in driving iron piling, it may be 
 justly inferred that considerable care and attention 
 must be requisite, in order that a blow of the ram 
 should fall with its due effective force upon the 
 exact centre of the pile-head. The great danger of 
 striking piles of timber obliquely, when it is the 
 intention of the engineer to drive them at right 
 angles to the horizon, has been strikingly exem- 
 plified at Westminster Bridge, where the rupture of 
 two arches of that structure was occasioned by a 
 defect of this kind. The iron piles at the Bruns- 
 wick Wharf were driven with a ram weighing from 
 13 to 15 cwt., with a fall of three feet six inches 
 only ; in some cases the fall was even limited to 
 a less extent. The crab-engine was invariably used 
 for this purpose. The tendency of iron piles to 
 start from their position when struck with a heavy 
 blow, suggested the propriety of driving them by a 
 series of smart shocks given in succession. By these 
 means the driving may be conducted with great 
 security and facility, care being taken in the first 
 instance to cap the head of the pile during the 
 operation with a sound piece or plank of timber to 
 transmit the shock more equally on the metallic 
 surface.* 
 
 * For a more elaborate detail of the preparations required for driv- 
 ing iron piling, such as boring the ground to receive the pile, cutting 
 trenches, &c., &c., the reader is referred to the first Volume of the 
 "Transactions of the Institution of Civil Engineers," published by 
 Weale, of Holborn, 1836.
 
 64 
 
 We shall now advert to the comparative per- 
 manency of iron piling. It has been practically 
 demonstrated that iron, buried in the earth under 
 water, and kept perfectly free from atmospheric 
 influence, will not sensibly corrode for an indefinite 
 length of time : indeed it may be safely affirmed 
 that nothing short of volcanic agency or great 
 intestinal commotions and changes, which in most 
 cases occur only at intervals of great distance of 
 time, will produce a decomposing effect upon iron 
 thus situated. A change, however, occurs in the 
 material; for it has been proved that iron thus 
 buried will, in process of time, obtain an extraordi- 
 nary degree of tenacity. The action of water upon 
 iron effects a result totally different, a certain che- 
 mical combination taking place, producing, within 
 a comparatively short period, a material resembling- 
 plumbago. This effect also takes place upon the 
 pistons of steam engines that have been subjected to 
 much work, the interior parts, consisting of the 
 wedges, &c., being readily cut with a knife. These 
 remarkable facts being known, it becomes an in- 
 quiry of great practical importance to ascertain the 
 cause or causes of such change of structure in this 
 metal, and also to discover some new compound 
 that will effectually resist the decomposing action of 
 water upon it. Experiments have not hitherto 
 been made to that extent as would funiish sufficient 
 data for a more close chemical investigation of this 
 subject. Until this be effected, the practice of iron
 
 CURVATURE OF WING 
 arid itl
 
 65 
 
 piling must be regarded with a much less fogree of 
 reliance than that of timber piling, securecnty satu- 
 ration with the bichloride of mercury. In addition 
 to the perpendicular pressure acting upon the hori- 
 zontal surfaces of piling, an enormous lateral thrust 
 is to be resisted in cases where river or sea walls, or 
 embankments, are raised upon piling. Considerable 
 care and attention is likewise requisite, in order to 
 give to the masonry that degree of facial curvature 
 most capable of resisting the effects of a lateral 
 thrust. The subjoined method has been employed 
 with uniform success in works where the thrust has 
 been great, or where land-slips have been appre- 
 hfcnded. The following is the construction of the 
 diagram shown in plate 4. Let A B, B C, be given, 
 join A' C, and bisect it in D, make D G = C B 
 -H- 4, join C G, G A, bisect them at I and K, let 
 H I, K J = ? join C J, J G, G H, H A, and so 
 on ad injinitum. 9 
 
 C, J, G, H, A, are points in a curve, that is a 
 tangent to A B, and projects B C. 
 
 Fig. 2 represents a retaining wall, with a cur- 
 vature produced from the foregoing formula. River, 
 wharf, and sea walls have occasionally to withstand 
 violent forces acting from without, caused by moor- 
 ing vessels thereto, or, by warping them in and out 
 of harbours, docks, and basins. The mooring-rings 
 are secured to the iron land-ties, and these latter are 
 firmly bolted to piles driven into the ground at the 
 back of the wall, in a slightly inclined position. The
 
 66 
 
 enormous horizontal strain to which these piles are 
 subjectS frequently causes them to yield, and conse- 
 quently the whole force is transferred to the backing 
 of the wall, which is mainly protected from being 
 pulled outwards by the security afforded by its batter, 
 or slope, and the strength of the fender piling, with 
 which the outer work is generally faced. As an 
 improvement on this method, we would suggest the 
 application of Mr. Mitchell's " Patent Screw Moor- 
 ing," fixed horizontally, and to which the tension 
 rod, forming the land-tie, might be firmly fixed. A 
 screw mooring of 3 feet diameter would thus have a 
 secure hold of an area not less than ten superficial 
 feet.* There are certain circumstances connected 
 with the practical operations of pile driving that 
 require a passing notice. 
 
 1st. It has been frequently found that when 
 piles have been driven to the depth that was at first 
 deemed desirable, another blow with the ram will, 
 to the great surprise of the engineer, suddenly sink 
 the pile to a greater depth than was effected in the 
 first instance. This effect may arise from several 
 causes : among the most probable of these may be 
 mentioned the sudden transition from a dense to a 
 looser soil, or the intervention of a stone immediately 
 under the foot of the pile, where the immediate 
 stratum is known to be sand. Now a smart blow, 
 accidentally given in an oblique direction, will cause 
 
 * For drawings, &c. of this excellent invention, see " The Public 
 Works of Great Britain," and " Mechanic's Magazine," No. 756, Vol. 28.
 
 67 
 
 the pile to swerve from its original upright position, 
 and to pass still further into the stratum, that was at 
 first supposed to be sufficiently consolidated to resist 
 the further efforts of the pile machine. Again : 
 when the head of tfte pile has been much bruised 
 by the action of the ram, the force becomes deadened, 
 and ultimately nullified by the comparative softness 
 of the abraded surface. In this case the top of the 
 pile should be cut off, and the driving continued on 
 the new and firm surface thus exposed to the ram. 
 Mr. Timperly* argues from these facts, that all 
 theories must be uncertain which profess " to ascer- 
 tain the actual weight a pile will bear, by having 
 given the weight of the ram, the fall, and the depth, 
 driven at one blow." This, however, is not the case, 
 as the theory has for one of its principal conditions, 
 the su^JDosed uniformity of the strata, through which 
 the pile is intended to be driven. 
 
 The most conclusive evidence in favour of the 
 enormous friction on the sides of a pile, and the con- 
 sequent degree of security to be relied thereon, is 
 shown by the immense power required to withdraw 
 them from their position, when once firmly driven 
 into the soil. The gentleman above alluded to has 
 given a particular statement of some operations of 
 this kind. " In removing the temporary bridges and 
 coffer-dams,t the piles were principally drawn by 
 
 * Account of the Hull Docks. 1st vol. Trans. Inst C. E. 
 t Hull Docks. Ibid. 
 
 F 2
 
 68 
 
 the engine crabs,* with double blocks and chains, and 
 so firmly did they hold, that some of them required 
 sixteen men with four crabs to remove them ; but 
 in general half this power was sufficient : after the 
 piles were started, one crab witlf four men (assisted 
 by the buoyancy of the waterf) accomplished the 
 business. The power applied to some of these piles 
 was not less than from fifteen to twenty tons. There 
 being occasion in the course of the week to draw 
 several of the sheeting piles in the Whitefriar-gate 
 lock pit, a 4-inch screw was used, and one of the 
 piles, 14 feet long by 12 inches wide, required, on 
 the most moderate calculation, a power of 18 tons 
 to draw it, the soil being nearly a- pure sand; 
 another pile could not be drawn by even a greater 
 force, until a hole was dug around it ; but the others, 
 being in softer ground, moved more easily. 3 * It is 
 further stated, that some of the permanent bearing 
 piles sustain a weight = 20 tons, without settle- 
 ment. 
 
 The operation of piling requires so much heavy 
 timber, and is withal of so expensive a nature, that 
 effective machinery for withdrawing piles from the 
 bed of rivers is a great desideratum. The timber 
 may afterwards be employed in other service, or 
 in works of the same description. In 1747 Marshal 
 Belleisle passed the Var to the army of the Allies, 
 
 The construction of a crab-engine is described further on. 
 f Query? Weight of the water.
 
 69 
 
 for the purpose of conquering an adjacent province 
 (Nice) ; and to facilitate the communication with 
 France, he caused to be constructed across that 
 river two magnificent bridges, measuring in length 
 about 300 toises each, and of sufficient solidity to 
 resist the force of one of the strongest currents in 
 Europe, at a time, too, when the river was most 
 subject to them. When the evacuation took place 
 in 1749, the bridges were destroyed. The founda- 
 tions, to use the words of M. Belidor, comprised a 
 " forest of piles." This writer communicated with 
 M. Guil, brigadier-general of the king's army, the 
 design of the machines shown in plate 5, figs. 1 
 and 2, as it was deemed necessary to withdraw the 
 whole of the piles, many of which were buried at 
 the depth of 12, 13, and 15 feet in the bed of the 
 river, and in an extremely tenacious earth. After 
 repeated trials to no effect, arising from the cords 
 breaking, they employed nine to each machine, and 
 the piles were then drawn with great expedition, 
 each in less than four or five minutes.* 
 
 The general construction of this machine is 
 explained by figs. 1 and 2. A beam, G L, is placed 
 upon a support or fulcrum, B ; the end of the beam 
 G is bound with iron straps, having a hook, Z, to 
 lay hold of the cord or chain, which is fastened to 
 the pile C, by means of a short bar or rod of iron 
 driven through the pile; the beam is elevated for 
 this purpose by the windlass P, and when made fast 
 
 * Belidor, Architecture Hydraulique, Vol. I., p. 121, 122.
 
 70 
 
 at one end (Z) is released at L : consequently the 
 beam is allowed to fall by its own gravity, drawing 
 the pile C upwards. The length of the beam, in 
 this case, is supposed to be 18 feet, and the length, 
 G K, two feet ; but, in all cases, whatever the length 
 of the beam may be, divide the same into nine 
 equal parts, and allow one part for the length from 
 the extremity to the fulcrum at K. The action of 
 the apparatus may be rendered more powerful by 
 the workmen mounting upon the end, L, and 
 thrusting it downwards. 
 
 The substance of M. Belidbr's calculation of 
 the power of this machine is as follows : Let us 
 suppose the beam to be 18 feet long and 12 + 12 
 inches, and, as we have before stated, G K will be 
 2 feet long, and K L 16 feet in length. Now a 
 cubic foot of dry oak weighs about 60 Ibs. ; let us 
 take this as the basis of the formula. For greater 
 accuracy, make K H = G H, in order to consider 
 these two parts of the beam as being equilibrated. 
 Imagine that the rest of the weight H L is united in 
 the middle A, the centre of gravity of the part H L 
 to take the place of the power which is to act 
 upon the pile ; recollecting that this power will be 
 = 840 Ibs., which is the weight of 14 cubic feet of 
 dry oak, answering to the arm of the lever K A, 
 9 feet, whilst the K G, in regard to its effect, is 
 only 2 feet. Thus, in the state of equilibrium, the 
 power A of 840 Ibs. will be, to its action in drawing 
 the pile, as KG is to K A, or as two to nine.
 
 71 
 
 Following the rule, we shall find that this action 
 = 3780 Ibs., which can be augmented by the 
 thrusts given to it by the workmen mounted upon 
 " the end, R L. If we suppose four men acting to- 
 gether by supporting themselves by the cords D D, 
 fig. 2, suspended from the top of the machine to 
 prevent them falling, it will appear, that weighing 
 together 600 Ibs. at the extremity of the lever K Q, 
 which is equal to six times K G, their effect upon 
 the pile will be 3600 Ibs., which, added to 3780, 
 gives 7380 Ibs. for the force with which the pile C 
 will be drawn upwards. The power of the machine 
 may again be indefinitely increased, should the pile 
 refuse to move from these exertions: displace the 
 pullies from their position, M N, and fix a ring, F, 
 to the end of the beam, which will be kept raised by 
 the hook Z laying hold of the chain or rope attached 
 to the pile; a pulley is then .fixed at the foot of the 
 machine, and a cord or rope passed through the 
 ring F and the pulley at the bottom ; the workmen 
 will then pull horizontally at the bottom, and draw 
 the beam downwards with great power. 
 
 This machine may be also made to answer the 
 purpose of the ordinary pile machine, by fixing a 
 heavy ram at one end; it is then raised and allowed 
 to fall as usual, or might be worked after the manner 
 of a tilt-hanimer. Fig. 3 is another apparatus for 
 withdrawing piling. C is a screw supported in a 
 square timber framing, worked with the levers B A 
 in the manner of a capstan. The pile D is attached
 
 72 
 
 to the hook at the bottom by cords or chains, and is 
 of course drawn upwards. This may be readily 
 removed by boats from one place to another, its 
 principal defect is, that if the pile is very firmly 
 fixed, the stand will not remain so steady as might 
 be desirable for the purpose of its operation. The 
 weighing machine for withdrawing piles simply 
 consists of a flat-bottomed craft or barge, having at 
 one end a windlass, and at the other a strong chain, 
 which is also fixed round the pile intended to be 
 raised. In the centre of the barge are two stout 
 planks or beams, laid longitudinally, forming a 
 tram road for a truck, loaded to the amount of 
 several tons weight; the truck is made fast to the 
 chain coiled round the drum of the windlass. The 
 mode of operation is as follows: the truck is first 
 drawn to that end of the barge nearest the pile, 
 which depresses the -head of the barge in the 
 water; the chain is then fixed round the pile; 
 the windlass is now, in its turn, put into operation, 
 drawing the truck towards the opposite extremity of 
 the barge; the other end now becomes depressed 
 and raises the pile at the other end. 
 
 At Waterloo Bridge, Bramah's pump was used 
 for the purpose of withdrawing the piling. Fig. 4, 
 plate 5, shows the arrangement employed: A A 
 exhibits part of the piling of the coffer-dam ; B is 
 the pump fixed upon the top of the piling; by 
 working the lever, or handle C, water is withdrawn 
 from the cistern D, and forced through the copper
 
 PILE WITHDRAWING MACHINERY.
 
 73 
 
 pipe E, into an iron cylinder enclosed within a 
 casing of wood, F, firmly bolted to the piles ; the 
 solid plunger, G, is thus forced upwards, and raises 
 a beam, H, placed upon the fulcrum, I ; a loose ring 
 of iron, L, is dropped over the pile K, and the chain 
 M is passed several times round the beam H. The 
 loose ring, L, being drawn upwards, will shift itself 
 into an angular position, and M'ill take a purchase 
 upon the sides of the piles, causing it to follow with 
 the elevation of the beam H, until it is completely 
 withdrawn from its position. 
 
 We shall now proceed with an examination of 
 those artificial substrata, which, by their peculiar 
 preparation and properties, are included in the class 
 or genera of concreting mixtures. The first that 
 claims our most particular attention is the bbton of 
 the French. This substance has been (erroneously 
 we think) considered by several writers as identical 
 with our Concrete and the Smalto of the Italians. In 
 order that the reader may fully comprehend the 
 nature and properties of this important artificial 
 conglomerate, we offer in the following chapter a 
 translation from the highly valuable work of "M. 
 Belidor,* containing a detailed analysis of its com- 
 position and use. 
 
 The composition called beton is understood (in 
 a popular sense) to be a kind of mortar used by 
 
 * Architecture Hydraulique, vol. 4, section 2. De la maniere 
 d'employer le beton pour les fondationa faites au fond de 1'eau sans 
 batardcaux ni epuisemens.
 
 74 
 
 the French engineers, consisting of the following 
 materials and their proportions. Twelve parts of 
 pozzolano, or Dutch trass, six of good sand, nine 
 of unslacked lime, the best that can be had, thirteen 
 of stone scraplings, not exceeding the size of an egg, 
 arid three parts of iron scales from the forge. These, 
 being well worked together, must be left standing 
 for twenty-hour hours, or till it becomes so hard as 
 not to be separated without a pickaxe. The mortar 
 being thus prepared, a bed of rubble stone, not very 
 large, is thrown into the coffer, and spread all over 
 the bottom as nearly level as possible. They then 
 sink a box full of this hard mortar broken into 
 pieces, till it comes within a little of the bottom ; the 
 box is so contrived as to be overset or turned upside 
 down at any depth ; which being done, the pieces of 
 mortar soften, and so fill up the vacant space be- 
 tween the stones ; by these means as much of it is 
 deposited as will form a bed of about twelve inches 
 deep ; another bed of stone rubble is now thrown in, 
 and thus one layer of bbton and one of stone is alter- 
 nately deposited till the work approaches near the 
 surface of the water, when it is levelled to receive 
 the regular courses of masonry. The text minutely 
 describes the precautions necessary in the erection 
 of large works, and the general method of the pro- 
 ceedings adopted by the most scientific engineers.
 
 75 
 
 CHAPTER III. 
 
 ON THE NATURE AND APPLICATION OF 'BETON. 
 
 FROM THE FRENCH OF M. BELIDOR. 
 
 To initiate those who have had but little experience 
 in works such as these in question, we shall preface 
 our observations with a general and popular view of 
 the subject, that they may the more clearly compre- 
 hend the detailed description that we intend offering 
 to their consideration. With this view, therefore, 
 let us suppose that the services of the architect or 
 engineer are required to direct the construction of 
 the foundations for a fort or jetty in the sea, at the 
 depth of fifteen, twenty, or even twenty-five feet. 
 The works should be commenced by forming the 
 neoessary boundaries to mark the extent of the pro- 
 posed erections. The usual examinations of the 
 nature of the ground, the state of the levels, &c., need 
 not in this particular instance be made, for the space 
 so enclosed may be permanently raised, and com- 
 pleted at leisure, by filling it in with such materials 
 as are hereafter described. The foundations, there- 
 fore, need not extend beyond the enclosure required 
 for the walls, care being taken that they have a thick- 
 ness proportionable to the depth of the water. The
 
 76 
 
 interior surface being perfectly level, and the exterior 
 having a slope of a fifth or sixth of its height, as in 
 common revete?nens, in order to avoid unnecessary 
 toil and expense. The works, being marked out by 
 buoys, and guarded from the action of the waves by 
 a temporary counter mole, if judged necessary, are 
 commenced, by erecting a coffer-dam of the usual 
 construction, by piling, &c. This dam, how ever, need 
 not be so complete in its appliances as those generally 
 employed for the purposes of bridge building, where 
 the water is required to be withdrawn from the in- 
 terior of the dam, but is nevertheless to be constructed 
 with such regard to security as will enable it to with- 
 stand the force, &c. of water^from without, and the 
 pressure of materials, water, &c. from within. The 
 water of the interior will consequently be displaced 
 by throwing in the beton, with such apparatus as we 
 shall presently describe. It being of the first import- 
 ance that the cement should subside upon the natural 
 and consolidated layer, or stratum, means must be 
 employed to clear the bed of the river or sea from all 
 extraneous deposits : this can be effected by removing 
 the ground to the necessary depth, with a machine a 
 cuilliere placed on the summit of the coffer, which 
 may be advanced as the work proceeds, and will lay 
 open the ground to the depth of the firm stratum, 
 which, in most instances, will be but a few feet 
 below the alluvial deposit. Should the stratum itself 
 be found to consist of a muddy, loose, or friable qua- 
 lity, the common precautions mnst be resorted to.
 
 SIDE ELEVATION Or THE MACHINE. 
 fvr iin/nfrsi/ia tfi< "Biicn
 
 77 
 
 The coffer may now be filled with masses of 
 beton to the level of low water mark; but as 
 this mortar, in falling, would nevertheless have 
 to pass through a great head of water, it would 
 lose much of its value by the greater part of the 
 lime being washed away; means have therefore 
 been found, by a certain contrivamce hereafter men- 
 tioned, to lower it without the risk of having its pro- 
 perties destroyed. Although the coffer intended to 
 contain the masonry in question be very simple in its 
 construction, our description will be rendered more 
 intelligible by reference to the subjoined illustra- 
 tions, which represent the coffer in its working 
 state. 
 
 Fig. 1, plate 6, represents a side elevation; 
 the letters A B show the high water mark, and C D 
 the bed of the sea. The piles A B belong to the 
 ranges driven on both sides, to form the encaissement 
 for a distance of no more than 10 or 12 toises (so as 
 not to encumber the work, which, in most instances, 
 requires to be executed with extraordinary expedi- 
 tion). They are headed with a cap, D, to which the 
 higher pieces, E, are fixed, and the lower, G, sus- 
 pended by holdfasts or irons attached to H, to sup- 
 port the timbers, F, which compose the coffer, on 
 whose edge two thick planks, O, serving as a plat- 
 form to the rollers, R, carrying the machine for 
 throwing in the beton. The line I K marks the 
 bottom of the trench cut below the bed of the sea 
 C D ; and, lastly, the sides I, L, M, R, enclose the
 
 78 
 
 btton mixed with stones, wherewith the foundations 
 are commenced. Fig. 1, plate 7, represents a plan 
 of the coffer and machine, another elevation, which 
 will be found in fig. 1, plate 8 : thus these illustra- 
 tions, studied together, with reference to the letters 
 which mark the same throughout, leave no part of 
 the subject unexplained. 
 
 The width of the coffer being equal to the ' 
 thickness of the masonry, the rule is, when carrying 
 on works such as operations in the interior of a 
 haven, to -calculate this thickness at one-half of the 
 depth of the water ; but should the masonry be ex- 
 posed to the open sea, or a strong current, then it 
 ought to be two-thirds. By this rule, also, you will 
 judge of the proper distance between the two ranges 
 of piles, the strength of which will be proportionate 
 to the height of masrony and beton, and to the 
 depth they must be driven so as to penetrate some 
 feet in firm ground ; thus rendering them capable of 
 sustaining the impetus of the waves, and preventing 
 the masonry from spreading until it has acquired 
 solidity. 
 
 On this account, according to the nature of the 
 soil, they must be armed with iron (lardoirs et 
 frettess), and the timbers, F, cut off at three or four 
 feet above the level of the highest tides, so as to 
 secure the work against the action of the waves, 
 when it shall be sufficiently raised to encounter 
 them. These piles should be distanced according 
 to the height of the masonry, s6 that their common
 
 PLAN OF THE MACHINE 
 fif inimcrAina flit "littfn"
 
 LONGITUDINAL ELEVATION OF THE MACHINE, 
 frr i/nmersitifi tJir'Rttfn. "
 
 79 
 
 resistance may be proportionate to the power they 
 will have to overcome from its spreading ; always re- 
 gulated, however, according to its height : whenever 
 that does not exceed 10 feet, 6 feet from the centre of 
 one pile to the centre of the next will be sufficient. 
 At about 16 feet they should be 4 feet apart, but 
 when it rises to the height of 20 or 25 feet, the dis- 
 tance of 3 feet apart should not be exceeded. All 
 the piles should be securely bound together by a 
 cap, the two opposite rows being keyed together at 
 intervals, and having cross quarters traversing the 
 top of the coffer, the more effectually to secure it 
 against opening > these may be removed when the 
 bbton is consolidated, and completed by its uppermost 
 course of common masonry. These piles will be 
 again bound by two bands* placed internally, so as 
 to serve for supports to the vanages, the upper one 
 a great deal thicker than the lower, so as to admit 
 sufficient space for the sloping of the bank piling, 
 as much on one side as the other (which is seen in 
 the front elevation), wherever a pier or isolated 
 jetty is to be constructed. 
 
 But if the question refer to the casing of a quay, 
 or the foundation of a breakwater, then the slope 
 need only extend along the exterior side, the inte- 
 rior being perpendicular, so as to allow for the pres- 
 sure that the masonry will have to sustain from the 
 weight of the soil. Thus it will be readily seen that 
 
 * Wailing pieces.
 
 80 
 
 the two corresponding heads on the inner side 
 should be equal, or nearly so, according to the 
 intended slope, care being taken to place the 
 second a third or fourth of the water's depth, 
 according to the height of the coffer ; the only 
 means of fixing these are by suspension, with iron 
 holdfasts, or ropes attached to piles above high 
 water, as may be seen at H, thereby affording 
 space to work. Respecting the plank-piling, there 
 is- a visible necessity for making them not only of a 
 thickness proportionate to the height of water, and 
 spread of masonry, but also to the depth which may 
 be considered necessary for the trench (cut to carry 
 off the sand at the bottom of the encaissement, from 
 the firm ground), into which it is necessary that 
 they should be driven at least two feet. These obser- 
 vations are equally applicable with respect to the 
 piles; the quality of the soil should be examined 
 by frequent borings before the work is commenced, 
 which will, at the same time, determine the amount 
 of labour required for this portion of the opera- 
 tions. 
 
 Further, we shall merely premise that the 
 plank-piling should be well bound together by 
 grooves and wedges, according to the usual prac- 
 tice, and cut down level with the cap of the piles, 
 each being fastened to the bands, leaving no aper- 
 ture, however small, at the joints, in .order to secure 
 every particle of the lime and pozzolano within the
 
 ELEVATION OF A MACHINE 
 
 frr cuatsio French**, fw Fcurvdatioru tlfwUt Wmtfr
 
 81 
 
 proper limits, so as to preserve the masonry free 
 from flaws: this being accomplished, the ma- 
 chine a cuilltire* will be required to clear away the 
 sand. 
 
 We may observe en passant that the foregoing 
 description of a good encaissement is applicable to 
 coffer-dams, erected when it is requisite to drain 
 some part of the sea to enable us to clear away the 
 remains of ancient sunken works, which operation 
 sometimes costs more than that of their original 
 erection ; this proves the necessity of making marine- 
 works perfectly solid, taking into consideration every 
 possible circumstance that might happen to cause pre- 
 mature decay, or the chance of a remote failure. Our 
 knowledge of antique monuments evidently proves, 
 that with good materials, it is generally the fault 
 of those who know not how to employ them properly, 
 that their works are far from promising a lasting 
 durability, falling for the greater part to ruin during 
 the lifetime of their constructor. The pieces form- 
 ing the base of the machine in question, consist only 
 of three soles or logs A B, fastened to the transverse 
 beams C D, the two first being again strengthened 
 by the cross quarters E F. In the engraving these 
 are only dotted in like the rest, the base being 
 partly covered by the upper parts, but its position 
 may be readily ascertained, as it is shown in the 
 
 * Dredging Machine? (Translator.) 
 G
 
 82 
 
 side elevation, where the frame G H I K is repre- 
 sented raised on the third sole A B ; this frame 
 serving, with two others like it, to sustain the axle 
 of the wheel and cuilliere. A little examination will 
 be sufficient to explain it. 
 
 The machine is constructed on the model 
 of those employed for clearing Toulon harbour; 
 all the apparatus is carried on two small beams, 
 , 6, placed across the top of the encaissement, and 
 progressing gradually, after having cut one part of 
 the trench as far as is required. The handle of its 
 cuilliere passes between two rollers L M, against 
 which it works, viz., against the first, L, in descend- 
 ing, and the second, M, when ascending. This 
 motion is caused by the action of the wheel, and the 
 two principal ropes attached to the cuilliere ; the first, 
 N Z Y, causes it to dig or penetrate into the ooze, 
 and raises it again when full; this is done by turn- 
 ing the wheel from right to left. The second, 
 T V S O (the tire arriere), passing over the pulley 
 S, and against the rollers V, causes the cuilliere or 
 scoop to descend, after having emptied its contents 
 into a mud-boat, by opening the trap or valve, sup- 
 posed to be situated at Q, which is done by turning 
 the wheel in a contrary direction. Towards the 
 extremity of the handle, a third rope O P is bound, 
 the other end of which is belayed three or four 
 times to the third sole G K to steady the cuilliere by 
 means of the fastening at P ; to drive it into the
 
 83 
 
 ground, according to the progress of the wheel, 
 and to direct it so as to dig equally over the whole 
 width of the bottom ; when filled it can be raised by 
 slackening the rope. Lastly there is a fourth cord X, 
 passing over the pulley x, with which the foregoing 
 operation is sometimes effected, so as to assist in 
 raising the cuilliere when laden more than usual. 
 
 It is necessary to observe that this machine can 
 not only be used for raising the ooze from the bed of 
 the sea, but also on all other occasions where it is 
 necessary to excavate deep trenches in marshy lands, 
 moss, or moving bogs, in order to erect embank- 
 ments or causeways cased with masonry, &c. &c. 
 
 Two parallel rows of plank piling must first be 
 driven into the earth, the length and thickness of 
 them being proportioned to the depth that they are 
 required to be driven. They should be driven as 
 far as possible into the firm ground, and the loose 
 soil should then be removed entirely from the 
 encaissement or inclosure. One or more dredging 
 machines must now be employed to excavate the 
 remaining portion of the trench, until a secure and 
 firm substratum is obtained. 
 
 The entrance of the water into the inclosure is 
 of no immediate consequence, if sufficient care be 
 taken to sustain the exterior pressure by a judicious 
 arrangement of the cross quarters, keys, framing, 
 &c. Having obtained a good substratum, it must 
 be cleared as much as possible, and a gentle slope 
 given to that side opposite to the facing of stone, to 
 G 2 

 
 84 
 
 secure the foundations against the pressure the 
 lining will have to sustain, taking care that it be 
 sufficiently wide to dispense with counterfeits, as it 
 is probable that considerable difficulty might arise 
 in attempting to excavate short transverse trenches, 
 from the little play the. scoop could possibly have. 
 It is not requisite to level the ground with any 
 great degree of accuracy; even the masonry em- 
 ployed does not require it; on the contrary, the 
 little interstices that remain contribute to bind the 
 work more firmly together. If the firm ground is 
 discovered to lie very low, so that you are compelled 
 to build upon ground of an inferior degree of con- 
 sistency, then it is only necessary to dig six or seven 
 feet below the bottom of the water; after which 
 drive piles, placed chequerwise, three feet apart, as 
 far as you can with a heavy beetle; let their heads 
 reach just four feet above the ground at the bottom 
 of the foundations, without levelling them, which 
 can even be done in the water by the aid of false 
 stakes ; then cover these piles, and it will form a 
 compact mass. But if the ground should prove 
 marshy, you must excavate as deep as possible, sink 
 a timber grating, and drive the piles in the reticu- 
 lations, leaving them jutting as before; throw in the 
 beton as usual, and level it carefully over the entire 
 surface, so as not to load the grating more on one 
 side than on the other. 
 
 It is of the utmost importance that the plank 
 piling employed for the coffer-dam should be of the
 
 85 
 
 maximum degree of strength, well bound together 
 by redoubled wailing. The piles should be driven 
 as far as possible into the firm ground, to prevent so 
 soft a soil, as we have supposed, from giving way 
 when laden with the superincumbent masonry. 
 Observe, that the weight of the masonry should 
 contribute as much as possible to its firm consolida- 
 tion ; the greater portion of the water with which 
 the btion is saturated being expressed or forced out 
 by this means. It must be acknowledged that, by 
 placing the foundation thus, there can be no ob- 
 stacles presented, by the state of the ground, but what 
 may be successfully overcome ; in fact it is doubtful 
 that the before-mentioned cases could be otherwise 
 accomplished, for there can be no question about the 
 necessity of the dams, the erection of which might 
 be as difficult as that of the principal work. Would 
 it not be easy to prevent the leakage, and 'keep the 
 foundations continually dry ? To finish the descrip- 
 tion of the drawings, explanative of the machinery 
 for laying or immersing the bbton, it only remains to 
 be observed, that it consists of two uprights raised 
 on a frame Y, carried on two rollers R, serving to 
 move it along the encaissement : these uprights, 
 which are bound together by two tie-beams S T, 
 sustain the axle, from whence is suspended the 
 chest W, by two ropes always kept equidistant by 
 two rollers X, moving on one of the tie-beams-. This 
 chest is three feet square ; its bottom Z b is made to 
 move in the manner of a pump valve, on two pivots
 
 86 
 
 b, and fastened when shut by a catch m, below which 
 to a ring Z is attached a cord a Z, made fast to an 
 iron pin a ; the length of this cord must be regu- 
 lated, so that the case, being let down to within about 
 four feet of the bottom, can go no lower without its 
 weight forcing the catch to let go the bottom, which 
 then opening, permits the bbton to fall out. 
 
 This bottom is supported on two sides, by the 
 ends of the chains n fastened to the lower edge of 
 the chest, to support it in the position as it appears 
 (dotted) in the plate. When, by reversing the mo- 
 tion of the rollers, the chest rises, then re-fasten the 
 catch by drawing the attached cord rid; this is 
 done when out of the water by pressing the handle 
 b d, the catch m may then be loosed, thereby enabling 
 it to resume its vertical position, and to sustain the 
 bottom as before. We may now raise the chest to 
 a convenient height, and re-fill it ; to effect this, the 
 wheel must be fastened by tying the cord f to part 
 of the frame. It is requisite that the inside of the 
 chest should be very smooth, and the joints well 
 caulked ; that it be pitched without, and shut with a 
 ground lid ; that the column of water displaced by 
 its descent may not carry away any of the b&ton. 
 A layer of gravel is required to be laid in the chest 
 before filling it, in order that the b&ton or cement 
 may not adhere to the bottom. The interior of this 
 chest, which is three feet cube, contains twenty- 
 seven cubic feet of b&ton. It may be made larger, 
 in proportion to the foundation you have to make ;
 
 87 
 
 nevertheless (for fear of retarding the action of the 
 apparatus), it should not exceed four feet cube, which 
 will give a solid content of sixty -four cubic feet. 
 
 Vitruvius, speaking of beton, says, " it should 
 be composed of two parts of pozzolano to one of 
 lime." He undoubtedly means the latter to be 
 measured unslacked, and slacked when the cement 
 is made ; so that the consequent effervescence may 
 throw off a greater quantity of the salts contained in 
 the brocaille, and the incorporated pozzolano. It is 
 further supposed that this substance is equally at- 
 tainable as in Italy. M. Milet de Montville, who 
 has acquired (in the kind of building we are treating 
 of) an experience enlightened by good principles, 
 has made numerous experiments on the best manner 
 of compounding the beton having proved it most 
 successfully in the works which he has superintended. 
 Having chosen an even and well-beaten ground, take 
 twelve parts of pozzolano (Terrasse de Hollands, 
 or Cendre de Tourney), of which you will form a 
 circular wall of five or six feet in diameter, on which 
 place six parts of sand well sifted, free from earthy 
 matter, and evenly spread. Fill the interior of this 
 circle with nine parts of quick lime, well calcined 
 and pulverized with an iron beetle, and to cause it 
 to slack more quickly (in maritime works) throw 
 on sea-water in small quantities, stirring it from 
 time to time with an iron spatula. As soon as it is 
 reduced to a paste, incorporate the pozzolano and 
 the sand.
 
 88 
 
 The whole being well mixed, throw in thirteen 
 parts of unhewn stone, and three parts of iron dross 
 well pounded. If this latter ingredient cannot be 
 obtained, sixteen parts (instead of thirteen parts) of 
 rough stones or pebbles must be added, of a size not 
 larger than a pullet's egg. Let this composition be 
 well amalgamated for the space of an hour, after 
 which it must be left in heaps to coagulate ; for this 
 purpose the space of twenty-four hours will be suf- 
 ficient in summer or in warm climates, but in winter 
 it often requires the space of three or four days. 
 Observe to keep it protected from the rain, and not 
 to use it until it has sufficiently hardened to require 
 breaking with a pickaxe. It must be borne in mind, 
 that, though the bhon is employed in a consolidated 
 state, when it has passed through the water and has 
 reached the bottom it spreads and settles. The 
 plunging machine is advanced, according as a bed 
 of ten or twelve inches in thickness is spread over 
 the whole foundation ; after which place unhewn 
 stones of moderate size, the largest not exceeding 
 the fourth part of a cubic foot. These stones should 
 be carefully arranged side by side : they will sink 
 into the mortar, which is now in a soft state, but 
 which will, in the space of three or four months after- 
 wards, become indissolubly united, and its firmness 
 will increase with its age. This bed of stones having 
 been again covered with a fresh stratum of btion, 
 commence another, and so on alternately, even to 
 within six or seven feet of the surface of the water.
 
 . . 89 
 
 The use of the chest may now be dispensed 
 with, and the bbton may be thrown in with buckets 
 or baskets, care being taken that they be emptied 
 very near the surface of the water, it being essen- 
 tial to prevent the dilution of the cement, which 
 would otherwise be the case if it had to pass through 
 a great head of water ; for, the heaviest parts sink- 
 ing more rapidly than the others, all the strength of 
 the lime would be lost. It is evident that, by this 
 method the masonry may be looked upon as being 
 done according to the best rules of the art, as it is 
 composed of very small portions of materials, pre- 
 senting at the same time a large surface to the 
 bbton ; therefore, a great quantity of the salts neces- 
 sary to the concretion are detached. It has also this 
 convenience, that it may be laid without the assist- 
 ance of a mason, the simplest means only being 
 required to place it in its proper position, all the 
 workmen required for this purpose being a few car- 
 penters to make the chest ; besides, it is better to 
 keep the chest in which the artificial masonry has 
 been made, particularly in places exposed to the 
 waves of the sea or a rapid current of water. By 
 the foregoing method one of the jetties at Toulon 
 was constructed in the year 1 748. 
 
 The engineers of that place not being acquainted 
 with any method more available for fixing solid ma- 
 sonry in the sea without vexatious impediments, it 
 may be justly considered the best method of insur- 
 ing the most complete success. It is not to be
 
 90 
 
 apprehended that a facing stone, being detached, 
 would be followed by many others, and that all in 
 the water would fall successively to ruin ; and let us 
 ask, should we not calculate greatly on the economy 
 of being able to work without dams or draining, 
 which sometimes costs as much as the work itself ? 
 Is there not reason to be surprised, that a practice 
 of which the ancients made such good use should 
 be so little employed, except on the Mediterranean 
 coasts ? Nevertheless, it is equally applicable to seas 
 and rivers, to erect a quay, or the piers of a bridge, 
 in places which are never dry, and where there is 
 always a great head of water ; being preferable, in 
 most cases, to foundations made in " caissoons" laid 
 along the bottom of the river. 
 
 M. Milet de Montville having filled a chest 
 containing 27 cubic feet of beton, sunk it in the sea, 
 where it remained during two months, after which 
 it was drawn up to ascertain the consolidation it had 
 acquired. On inspection it was found to be con- 
 verted into so compact a body that more difficulty 
 was experienced in separating its parts, than those of 
 a block of the hardest stone. If a long foundation is 
 required to be made, and the work is exposed to the 
 violence of the waves, it is at first only necessary 
 to drive the piles of the encaissement following the 
 intended lines, and only form the coffer with plank 
 piling, in parts of six toises in length, to fill it im- 
 mediately with masonry, that each part may resist 
 the violence of a heavy sea, which would probably
 
 91 
 
 overturn an empty encaissement* In order to com- 
 mence the work again after having continued the 
 encaissement, the side partitions formed with plank 
 piling are to be removed ; if the beton is already 
 firm, some apertures must be made in the side, by 
 which means the new masonry will key or bind 
 better with that already erected. If, on the contrary, 
 it has not become a uniform body, it will incline 
 itself along the encaissement, and will naturally join 
 with the beton which is thrown over it. 
 
 It is almost needless to observe that, according 
 to the circumstances of situation, &c., boats or lighters 
 must be in attendance with proper rigging, to carry 
 the materials and rafts of timber round the encaisse- 
 ment to assist in the work. The foundation having 
 been left, at least during the winter, to allow it 
 to harden, the masonry must be raised by regular 
 courses ; the fencing should be of good hard and 
 picked unhewn stone, whether for the construction 
 of a mole, jetty, battery, or a fort. If the surface is 
 exposed, and likely to be abraded by the action of 
 the sea, or by continual concussions arising from 
 external forces as is the case in quays, &c. ; it is 
 imperatively necessary that the edging of stone 
 should be of sufficient substance, the headers and 
 stretchers placed " en coupe" joggled together with 
 iron dowels run with lead. 
 
 If works of magnitude are to be erected, jutting 
 far out and of considerable length such as a jetty
 
 92 
 
 or a mole it is sufficient to make an encaissement 
 all round, to inclose the beton masonry : then fill 
 the space so inclosed with unhewn stone, after which 
 continue to raise the same lining of good masonry in 
 freestone, placed in regular courses up to the top of 
 the platform, allowing a moderate size for the en- 
 caissement, so as not to create useless expense. In 
 order that a greater degree of solidity may be 
 allowed where necessary, the opposite walls should 
 be bound by chain bars, placed at regular distances, 
 effected either by encaissement or by beton masonry. 
 It may be added, that in building the circummuring 
 of a fortification, or of any other work much exposed 
 to the open sea, and when, notwithstanding the 
 counter-jetty with which it is guarded, there is rea- 
 son to fear that the waves might dash against the 
 face of the work, causing much damage by their 
 violence, the exposed works should be protected by 
 covering them with inch-and-half or two-inch plank- 
 ing, securely bound together with cramps, and per- 
 manently fixed against the masonry for the first year, 
 until the whole should have time to consolidate and 
 harden, and that the joints should not open. As 
 there are some remarkable particulars connected 
 with the use of beton, we shall probably interest 
 those concerned in its use, by subjoining the results 
 afforded by its extensive application at Toulon. 
 
 The statement contains the quantities of each 
 kind of materials contained in a cubic toise of this
 
 93 
 
 masonry, and their weight. To fill a foundation 
 containing sixteen cubic toises, is as follows : 
 
 Cubic Feet. Ibs. 
 
 942 Of Red Pozzolano, at 90 Ibs. the foot, making 84,780 
 
 471 Of Sand, at 115 Ibs 54,165 
 
 235 Pounded Iron Dross, at 80 Ibs 18,800 
 
 1,020 Rubble Stone, at 110 Ibs 112,200 
 
 706 Quick Lime, at 76 Ibs. each 53,656 
 
 618 Stones, at 160 Ibs 98,880 
 
 3,992 Total cubic feet, weighing 422,481 Ibs. 
 
 Thus it is seen that to make 16 cubic toises of 
 bkton masonry, there is used 3,992 feet of materials, 
 although these sixteen feet only contained 3,456 solid 
 feet, thus the difference is 536 cubit feet, caused by 
 the vacuity between the parts of the materials em- 
 ployed ; respecting which it is to be remarked, that 
 M. Milet de Montville has often proved that 2 cubic 
 feet of rough sand, incorporated with 1 foot of 
 slacked lime, would not produce more than 2 feet of 
 mortar ; from which it follows, that in the account 
 of the materials employed in this masonry, care 
 should be taken to make proper deduction for the 
 lime.
 
 94 
 
 CHAPTER IV. 
 
 ON THE ANALYSIS OF LIMESTONE. 
 
 THE extraordinary phenomena exhibited by the 
 combination of lime with siliceous matters, and the 
 variable results that are effected by modifying the 
 proportions of the component parts in the com- 
 position of cements and mortars, for building pur- 
 poses, are of the utmost importance to the prac- 
 tical builder. An elucidation of the facts connected 
 with this portion of our labours is of so much 
 practical and scientific interest, that we shall offer 
 no apology for taking, as far as our limits will 
 permit, a comprehensive view of the subject. There 
 are two theories relating to the formation of lime. 
 The first of these was promulgated by the earlier 
 geologists, and up to the present time, has been 
 advocated by several scientific men. This theory 
 .contends for the origin of limestones from organized 
 substances, or, in other words, that it may be " an 
 animal product, combined by the powers of vitality 
 from some simple elements." 
 
 The arguments deduced in opposition to this 
 hypothesis have been ably pointed out by Mr. Lyell,
 
 95 
 
 in his " Elements of Geology," who contends that 
 lime is formed by the evolution of carbonic acid, 
 and a small quantity of carbonate of lime on the 
 sites of springs. The immense deposits of carbonate 
 of lime originating from springs in volcanic districts, 
 he attributes, with great propriety of reasoning, to 
 the solvent power of carbonic acid ; and instances 
 that, " as acidulous waters percolate calcareous 
 strata, they take up a certain portion of lime, and 
 carry it up to the surface, where, under diminished 
 pressure in the atmosphere, it may be deposited, or, 
 being absorbed by animals and vegetables, may be 
 secreted by them." 
 
 Limestone,* when burned, is deprived of its 
 carbonic acid, &c., and becomes converted into lime, 
 its chief constituents being a metallic oxide^ com- 
 bined with oxygen. For the manufacture of mortar, 
 lime requires slacking, which is accomplished by 
 wetting it with a certain proportion of water, a 
 compound is thus formed, bearing the chemical 
 name of " hydrate of lime." 
 
 It is evident that, to acquire practical informa- 
 tion concerning the properties of various limes, an 
 analysis of a series of limestones must be the first 
 step to obtain the requisite information. The stu- 
 dent should, nevertheless, be apprised that chemical 
 examination alone will not enable him to decide 
 upon the quality of the material, but that his research 
 
 * Limestones are compounds of carbonic acid with salifiable bases. 
 t The metallic base of lime ia " Calcium," and was discovered by Sir 
 H. Davy, in the yar 1808.
 
 .96 
 
 should, in all cases, be accompanied by actual expe- 
 riment. Calcareous minerals are commonly distin- 
 guished by their effervescing and dissolving in acid, 
 and the readiness with which their surfaces may be 
 cut or scratched with a knife ; their elements may be 
 readily and accurately ascertained by the analytical 
 process hereafter described. 
 
 The analyses contained in this chapter have 
 been mostly derived from the " Transactions of the 
 Geological Society of London," a series of publica- 
 tions containing papers of great practical value to 
 the engineer, &c. From the authenticity of those 
 records, and the scientific eminence of the writers, 
 it is anticipated that the various analyses thus col- 
 lected and brought under immediate observation, 
 will not fail to assist in developing the nature and 
 quality of a most important class of building 
 materials. 
 
 Lime may be obtained from an immense variety 
 of stones ; indeed, any stone exhibiting the indica- 
 tions mentioned above, will burn to lime ; varying in 
 quality in proportion as it is more or less impreg- 
 nated with silex, alumina, iron, &c., the pure lime- 
 stones furnishing the weakest lime* Chalk is the 
 most common variety of calcareous mineral from 
 which lime is obtained ; its physical character is so 
 well known as to need no remark. We shall merely 
 observe, that when quarried, the less exposure it 
 
 * M. Vicat states, " that no hydraulic mortar exists without silica, 
 &c." An exception has, however, been observed by Captain Smith, in 
 favour of the lime made from Dolomitic or magnesian limestones. (See 
 Captain Smith's translation of " Vicat on Cements.")
 
 97 
 
 has received from the atmosphere, the better will be 
 the quality of the lime. Most of the lime used in 
 the neighbourhood of London and its suburbs is 
 procured from Dorking, in Surrey. This lime is 
 produced by burning masses of indurated chalk,, or 
 chalk marie. Chalk forms an extensive and con- 
 spicuous geological feature in this island ; its great 
 abundance, and the ease with which it is obtained, 
 renders it a most available medium for the manu- 
 facture of lime. 
 
 The specific gravity of an ordinary specimen 
 of chalk is 2.3, and, according to the analysis of 
 Bucholz, contains 
 
 Lime 56 5 
 
 Carbonic Acid . . 43 
 Water 5 
 
 100 
 
 In its purest state it is a carbonate of lime ; but 
 the usual varieties contain much siliceous matter, 
 which is separated from it by pounding and 
 washing. 
 
 Chalk may with propriety be considered as 
 a "tender earthy limestone," the second in the 
 scale of materials from which lime is made. 
 Thus we consider lime made from the varieties 
 of argillaceous limestones, 1st ; chalk, 2nd ; and 
 that made from shells, the 3rd. Near Dorking 
 is one of the escarpments of the chalk range, 
 and at two-thirds or three-fourths of the depth 
 H
 
 98 
 
 of the chalk strata, a very hard chalk is obtained, 
 having a brownish tinge ; this is quarried, broken, 
 and burned, and forms the substance so well known 
 by the name of Dorking lime. In proportion to the 
 depth at which the chalk is obtained, so is its state 
 of induration, in this respect not differing from 
 other strata. It has been remarked, that within a 
 few yards of the bottom of the chalk formation, there 
 are one or more beds of it so hard as to be nearly 
 equal to the best Portland stone. In many places its 
 induration is so great, that it has been quarried for 
 the purposes of masonry ; the following may be 
 cited as instances of its employment as a building 
 stone : The abbey of Sturley, and its parish church, 
 Berkshire : abbey of St. Omer's ; mullions and arches 
 of St. Catherine's chapel near Guildford, Surrey, &c.* 
 A lime obtained from Merstham in the same county 
 (Surrey), is also extensively used ; it is obtained 
 from an indurated chalk marie (clay and chalk), 
 the kilns used for burning it into lime are distri- 
 buted in various parts of the county ; those at Mers- 
 tham are situated at the lowest level at which the 
 marie is fit for the kiln, beneath which it becomes 
 much harder and partakes of the nature of stone.f 
 The more argillaceous forms of chalk marie, accord- 
 ing to the analysis of Mr. Phillips, indicate carbonate 
 of lime nearly 30 per cent. ; and the more cretaceous 
 varieties 82 per cent, carbonate of lime, 18 silex and 
 
 * Conybeare. 
 
 f Middleton. Communication, Monthly Magazine, 1812.
 
 99 
 
 alumine, chiefly the former, and a trace of the oxide 
 of iron. 
 
 For the greater convenience of the reader, we 
 shall follow (as closely as the subject will admit) the 
 regular geological succession of strata, in order to 
 exhibit successively the limestones peculiar to each 
 formation. The limestone from which the greater 
 number of the varieties of lime have been made and 
 experimented upon, were of the sub-species.* 
 
 According to Dr. Ure, compact limestone com- 
 mon to the English mining districts is a carbonate of 
 lime, having variable and minute portions of silica, 
 alumina, iron, magnesia, and manganese ; it effer- 
 vesces with acids and burns into quicklime. Sp. 
 gr. 2.6 to 2.7. 
 
 Oolitic series. 1. Portland. The summit of 
 the Portland beds, called the cap, is only burned for 
 lime. The cap is No. 4 of the layers of the quarries ; 
 it is a cream-coloured stone in three layers, with 
 partings of clay, and so hard as to turn the steel 
 points of chisels and pickaxes. 
 
 2 . Cornbrash. A loose mbbly limestone, affords 
 lime of tolerable quality. 
 
 3. Forest marble, a very shelly limestone. 
 
 4. Bath stone. Now extensively worked for 
 the purposes of masonry : it is a tolerably pure car- 
 bonate of lime, but as a lime, possesses no remark- 
 able features. The oolitic series contain such an 
 
 * For this enumeration, see lire's Chemical Diet. Art. "Limestone." 
 H2
 
 100 
 
 immense number of intermediate beds of stone, 
 capable of being converted into lime of variable 
 quality, that the bare enumeration of them would 
 occupy a very considerable space. It is sufficient 
 for our present purpose to observe, that throughout 
 the whole tract of country occupied by these forma- 
 tions,* little difficulty is experienced in procuring 
 limestone fit for the purposes of the arts, particularly 
 that of masonry. They are, in fact, the grand de- 
 positories from whence we draw the materials for 
 our supply of building-stone ; and furnish, besides, 
 inexhaustible materials for the use of the brick- 
 maker and lime-burner.'f 
 
 The series alluded to above (geologically speak- 
 ing) include all the strata between the iron sand and 
 the red marie. These comprise three great divisions, 
 called the upper, the middle, and the lower oolitic 
 systems or divisions ; each separated in a remarkable 
 manner by an extensive argillaceous district or valley. 
 This important circumstance so well defines the boun- 
 dary of each division, that the architect or engineer 
 may readily detect the general quality of the sub- 
 soil by the locality of the separations. The stony 
 beds of the first division are the Purbeck, Portland, 
 Tisbury, and Aylesbury limestones, &c. Then fol- 
 lows the valley of clay, known generally as the oak- 
 
 * Comprising a zone having nearly thirty miles average .breadth, 
 and extending across the island from Yorkshire, on the north-east, to 
 Dorsetshire, on the south-west. (Conybeare). 
 
 f The chapter on building-stone will describe the more remarkable 
 divisions of the strata.
 
 101 
 
 tree clay. 2nd. Coral rag, &c. &c., divided by the 
 Oxford or clunch clay. 3rd. Corn-brash, or corn- 
 grit, forest marble, great and inferior oolite, contain- 
 ing the Bath stone, &c. The lias, and lias marie, 
 forming the base of the whole. 
 
 For the manufacture of cement, the lias lime- 
 stone must be allowed to hold the most prominent 
 place in the above series. In the neighbourhood 
 of Bath, the dislocations and disruptions of the in- 
 ferior oolite, together with quarrying through the 
 strata of stone, have laid open the lias formation; 
 from hence is supplied the lias lime, so exten- 
 sively used in Wiltshire and the adjacent districts. 
 In the recent alterations at Heywood House,* at 
 Westbury, and at other extensive works in Wiltshire, 
 the lias lime has been used as a cement in all under- 
 ground or damp situations: its known property of 
 setting under water renders it invaluable for such 
 
 * In Wiltshire and Somersetshire, the provincial terms for the beds of 
 stone available for building, and procured from the Box-stone-quarries, 
 are, 1. Corngrit; 2. Scalit; 3. Ground stone; 4. Farley-down stone; and 
 5. Coombe-down stone. The corn-grit and scalit are of a tolerably fine 
 texture, but not weatherproof. Ground stone is an excellent weather 
 stone, though somewhat coarse : it is well adapted for plinths, quoins, and 
 projections that are much exposed to the weather. Farley-down stone 
 ought to be employed for carvings and mouldings in interior work, but 
 is not proof against the weather; if employed externally, sufficient time 
 should always be allowed for the rock water (which it contains) to eva- 
 porate, otherwise the first attack of frost will disintegrate the whole 
 mass, causing it rapidly to fall to pieces : it should not be used in damp 
 situations. Coombe-down stone is of a coarser quality than Farley- 
 down stone, it is much harder, and of a gray colour : it is generally 
 considered by masons as weatherproof, and may be used for almost any 
 external purpose : the top beds are considered the best.
 
 102 
 
 purposes. In the immediate neighbourhood, it is 
 known among masons by the name of Bath brown 
 lime, and when prepared for cementing, or in com- 
 bination with the patent metallic cement, is what is 
 locally termed " wind slacked-," namely after hav- 
 ing been burned, it is placed in covered sheds, but 
 open at the sides, the atmosphere being allowed to 
 operate upon it; should the slacking proceed too 
 slowly, a small quantity of water may be sprinkled 
 upon it to stimulate the process, but on no account 
 should water in a considerable quantity be added; 
 it is therefore much better (if possible) to allow 
 the atmosphere to act for this purpose. The 
 lime, when thus slacked, is converted into fine 
 granulated particles, and is among workmen said 
 to be " alive," as it will run from an iron shovel 
 similar to quicksilver. The colour of the lias, pre- 
 vious to burning, is blue; when it has passed 
 the kiln, it is brown. The uniformity of its mine- 
 ralogical character is well retained throughout, in- 
 cluding also its foreign localities, which are very 
 extensive : a correct knowledge of the lias limestone 
 is, therefore, of almost universal application. Al- 
 though a minute analysis of the lias limestone has 
 not yet been made, we may calculate upon the 
 greater number of specimens containing as much 
 as 90 per cent, of carbonate of lime, the residuum 
 in all probability consisting of alumen and iron. 
 Mr. Smeatori experimented upon the following 
 varieties of lias lime, by dissolving 40 grains of
 
 103 
 
 each in aquafortis, and obtaining a precipitate from 
 each amounting to the. following quantities : 
 
 Graiiia. 
 
 Yellow Lias, of Axminster 5| 
 
 Do. with shining spangles . . 05 
 
 Yellow Such-stone, of Glastonbury . . 5 
 
 Blue Lias, of Watchet 4.| 
 
 Do. Aberthaw (Wales) ... 4^ 
 
 Do. Bath 4 
 
 Do. Axminster* 3 
 
 The next important limestone deposit f is that 
 associated with the red marie, or new red sandstone. 
 This is denominated the newer magnesian, or con- 
 glomerate limestone, from its containing an excess 
 of magnesian earth. The chemical and external 
 characters of this limestone are, a granular sandy 
 structure, glimmering lustre, and a yellow colour ; 
 it contains about 20 per cent, of magnesia. The 
 abundance of this limestone in England renders it 
 an important object of notice, and the analysis of 
 its varieties will not fail to furnish useful information 
 to the engineer. It should be observed, however, 
 that in the composition of rocks (and more par- 
 ticularly the one in question) the same anomalies 
 present themselves that we find occurring so re- 
 peatedly in experiments upon the strength and 
 stress of materials, where it has been found, that 
 
 * Conybeare, Geol. Eng. and Wales, p. 263. 
 
 t " The limestone of St. Vincent's rocks near Bristol (associated 
 with the lias), when calcined, yields a very pure lime; large quantities 
 of it are exported for the use of the sugar works in the West Indies, in 
 an unslacked state, and packed in tight casks, it is used extensively in 
 building.'' Dr. Bright on the strata in the neighbourhood of Bristol, 
 vol. 4, Geol. Trans, p. 200. 
 
 t Also called dolomite.
 
 104 
 
 scantlings of the same size, from the same mass, 
 and apparently of the same quality, offer results 
 widely differing from each other : so, in the mag- 
 nesian limestone formations, in one place we meet 
 with a common limestone, and in another spot not 
 far distant an excess of magnesia ; even the same 
 stratum (observes Dr. Gilley) " will vary in its 
 colour, hardness, and general structure, in different 
 parts of its course." With the rationale of this 
 phenomenon we have, at present, nothing to do ; the 
 fact is here mentioned with a view to guard the 
 inquirer against the apparent contradiction that 
 may arise in the course of his investigations. The 
 principal range and extent of the magnesian conglo- 
 merate formation is from Sunderland to Notting- 
 ham. It makes its appearance in various other parts 
 of this island, as will be seen by the localities 
 described in treating of the several specimens 
 selected for analysis. The continuity, however, is 
 most apparent through the line of country alluded 
 to above. A specimen of the magnesian limestone 
 of Yorkshire, has been analysed by Smithson 
 Tennant, Esq. ; it was procured from the stone of 
 which York Minster is built, and found to contain 
 as follows : 
 
 Carbonic acid . . 47 00 
 
 Lime 33 24 
 
 Magnesia . . . 19 3G 
 
 Iron and Clay . . 40 
 
 100
 
 105 
 
 - A similar variety, namely, that of Westmin- 
 ster Hall, yielded results nearly alike, but exhibiting 
 about two per cent, less of magnesia. 
 
 The magnesian limestone of Sunderland is 
 situated to the north-west of the red sandstone. 
 The northern extremities of the western boundary 
 of the magnesian limestone are exposed in the cliffs 
 at Cullercoats in Northumberland. On the coast in 
 the vicinity of South Shields, in the county of Dur- 
 ham, the formation becomes extensive, and may be 
 followed till it readies tfye Tees below Winston- 
 bridge, thirty miles south-west of that river's junction 
 with the sea, and for four miles from the Tyne at 
 South Shields. The celebrated quarry at Whitby, 
 near Cullercoats, offers an admirable opportunity 
 for the examination of the limestone of this district, 
 and is minutely described by N. J. Winch, Esq. 
 (4th vol. of the Geological Transactions), to whom 
 we are indebted for a highly valuable paper, on the 
 geology of Northumberland and Durham, from 
 which the following account is extracted : " A 
 hollow space, formed like a basin or trough, is filled 
 with the limestone ; the length of this from east 
 to west is about a mile ; the breadth from north to 
 south four hundred yards ; the depth seventy feet. 
 The beds pass over the Ninety-fathom Dike, which 
 has occasioned in them no confusion or dislocation ; 
 so that there can be little hazard in stating-, that 
 the beds of the magnesian limestone belong to a 
 more recent formation than those of the Coal-field.
 
 106 
 
 The limestone has been quarried across its whole 
 breadth, and a numerous set of thin strata are thus 
 exhibited to view. At the surface loose blocks of 
 a bluish gray coralloid limestone, the produce of the 
 lead mine district, are found imbedded in the soil. 
 Three or four of the uppermost strata of the quarry 
 are of white slaty limestone, which being nearly free 
 from iron, burns into a pure white lime. Below 
 these an ash gray firm-grained stratum is met with, 
 which strongly resembles a sand-stone, and seems 
 to contain nearly as much iron as the ferri-calcite of 
 Kirwan, becoming magnetic by the action of the 
 blow-pipe : it produces a brownish yellow lime, less 
 esteemed for agricultural purposes than the former. 
 The beds next in succession are of an ash gray 
 colour, are compact in texture, and conchoidal in 
 fracture ; these afford a buff-coloured lime, which 
 sells for nearly the same price as the white : near 
 the bottom of the quarry the limestone alternates 
 with shale ; the whole rests upon a stratum of shale 
 on the southern side, and upon a thick bed of sand- 
 stone on the northern. The shale has been cut 
 through to a considerable distance from the kilns in 
 the direction of North Shields, for the purpose of 
 laying a railway to the Tyne. The thickness of the 
 limestone strata varies from three or four inches to 
 as many feet. Small strings of galena have been 
 found here, and in one of the strata, that was walled 
 up when I visited the quarry, a few organic remains 
 have been noticed. The stone intended to be burned
 
 107 
 
 is detached from the rock by the agency of fire, 
 during which process those portions which contain 
 iron become of a brick-red colour. Considerable 
 quantities of fuel are found necessary at the kiln, 
 and some parts of the rock are too apt to vitrify in 
 the process ; an accident to which the crystalline 
 limestone of Sunderland is not liable." 
 
 The limestone quarried in the vicinity of Sun- 
 derland is of a brown colour; it contains inflammable 
 matter, and, consequently, requires less fuel for its 
 conversion into lime.* The Northumberland and 
 Durham limes exhibit the following products from 
 an analysis of 100 parts of each : 
 
 By the Rev. J. Holme, from Denton, near the Tees. 
 
 Carbonate of Lime 63 
 
 Ditto of Magnesia 30 
 
 Alumina, Red Oxide of Iron and Bitumen 2 25 
 Water . 25 
 
 100 
 
 By Sir H. Davy, from Eldon. 
 
 Carbonate of Lime 52 
 
 Ditto of Magnesia 45 2 
 
 Iron 11 
 
 Residuum 17 
 
 100 
 
 * The exportation of lime from Sunderland is chiefly to Scotland, 
 and amounts to from forty-two to forty-five thousand chaldrons, of 
 thirty bushels each, annually.
 
 108 
 
 By Sir H. Davy, from Ay cliff. 
 
 Carbonate of Lime 45 9 
 
 Ditto of Magnesia . . . ....,,- . . . 44 6 
 
 Iron 1 57 
 
 Residuum . ' ; ' ; ' . . 28 
 
 100 
 
 Some specimens of this lime have the pro- 
 perty of setting under water ; and, when mixed 
 with bullock's blood, forms a strong iron cement, 
 occasionally used for repairing boilers. The lime 
 from Leigh and Ardwick was employed at Drury- 
 lane Theatre, and used as a Tarras in those works. 
 In the neighbourhood of Bristol there is a remark- 
 able instance of the conglomerate limestone appear- 
 ing in contact with the new red sandstone. The 
 basis of the red ground, or new red sandstone, is in 
 most cases a common limestone ; but at the village 
 of Portishead, near Bristol, a discovery was made 
 by Dr. Gilby, of a limestone containing a consider- 
 able quantity of magnesia ; the stone was of a 
 yellow colour, resembling the Yorkshire magnesian 
 limestone. In some strata it is so mixed with sand 
 as to give more than 20 per cent, of insoluble 
 matter. The fragmented portions are generally 
 limestone or red sandstone ; but it is found that 
 other strata are destitute of sand and fragments, 
 forming, in fact, a hard compact magnesian lime- 
 stone. This variety will give 36 or 38 per cent, of
 
 109 
 
 carbonate of magnesia. A compact variety yields 
 as follows : 
 
 Carbonate of Lime 53 5 
 
 Ditto of Magnesia 37 5 
 
 Oxyde of Iron 08 
 
 Insoluble matter 70 
 
 Loss . .' ;.' .. '."". ....... 12 
 
 100 
 
 A small ridge of rock, about four miles north- 
 west of Bristol, upon which Lord de Clifford's house 
 is built, is entirely composed of a magnesian lime- 
 stone. A specimen yields as follows : 
 
 Carbonate of Lime 58 
 
 Ditto of Magnesia 38 
 
 Oxide of Iron 11 
 
 Silica and Bituminous matter .... 15 
 
 Loss 1 4 
 
 100 0* 
 
 The quantity of magnesia contained in lime- 
 stone does not appear to operate injuriously upon 
 lime employed for building purposes, although its 
 presence, when used for agricultural purposes, is 
 anything but favourable to vegetation. The pre- 
 sence of magnesia in limestone used for building 
 produces scarcely any other effect than to render 
 the proportion of clay greater in relation to the 
 
 * Dr. Gilby on the magnesian limestone in the neighbourhood of 
 Bristol. Vol. iv., Geol. Trans., p. 212.
 
 lip 
 
 proportion of carbonate of lime. In order to ap- 
 preciate the qualities of a calcareous stone as a lime- 
 stone, it is sufficient to determine the quantity of 
 argile and magnesia contained in it. The simple 
 process by which this is effected is thus described 
 by M. Berthier in the Annales de Chimie.* " Pul- 
 verise the stone, and pass the powder through a 
 silken sieve ; put ten grains of this powder into a 
 capsule, and pour over it a little at a time, muriatic 
 acid, nitric acid, or vinegar diluted with a small 
 quantity of water, agitating it at the same time with 
 a glass tube or small stick ; discontinue adding the 
 acid when it ceases to effervesce; then evaporate 
 the solution with a gentle heat, until the whole is 
 reduced to a pasty consistence ; dilute it in about 
 half a litre of water, and filter it ; the clay remains 
 on the filter, and must be dried in the sun or by 
 a fire, and weighed ; or it will be better before 
 weighing' to calcine it to a red heat in an earthen 
 or metal crucible. Pour very limpid lime-water 
 into the solution, as much as to cause a precipitate ; 
 collect this precipitate, which is the magnesia, as 
 quickly as possible upon a filter ; wash it with pure 
 water, calcine or otherwise dry it as much as pos- 
 sible, and then weigh it. If there be any iron or 
 manganese in the solution, they will precipitate 
 with the magnesia. It would be superfluous to 
 attempt to separate these three substances from 
 each other." 
 
 * See also Repertory of Patent Inventions, vol. 43, N.S., p. 185-6.
 
 Ill 
 
 Carboniferous Limestone. Associated with the 
 all-important coal districts of this country is a vast 
 geological formation known by the above name, 
 which significantly points out its characteristic lo- 
 cality, and at the same time serves materially to 
 mark the distinction between the magnesian lime- 
 stone beds associated with the red ground or new 
 red sand-stone. This rock exhibits generally a 
 close and compact body, capable of a good polish, 
 and imperfectly crystalline,* prevailing colour gray. 
 The purest beds contain about 96 per cent, of cal- 
 careous matter. By admixtures, not common to the 
 pure species, it passes into magnesian, ferruginous, 
 bituminous, and foetid limestone. For the manu- 
 facture of lime, possessing all the essential qualities 
 of a cement, capable of the highest degree of indu- 
 ration, the carboniferous limestone of England is 
 upon the whole the most important in the class of 
 calcareous minerals. From some unaccountable 
 reason, the valuable properties of this mineral have 
 not been sufficiently appreciated by the profession ; 
 its use has, consequently, been very limited in our 
 metropolitan works. In engineering operations 
 good lime is a material that ought to be obtained, 
 regardless of expense. Indeed, when it is con- 
 sidered, that artificial hydraulic limes, such as are 
 generally used in the metropolis, are obtained from 
 a variety of ingredients collected in various districts 
 
 * Conybeare.
 
 11-2 
 
 distant from each other, and subjected to careful 
 manipulation, it becomes a question whether the 
 conveyance of the best varieties of this mineral to 
 the London market would not prove of sufficient 
 practical value to counterbalance the excess of outlay 
 required in its general employment in our public 
 works. The carboniferous limestone of Flintshire, 
 North Wales (parish of Whiteford), exhibits in an 
 eminent degree the valuable properties of the bitu- 
 minous limestone. A careful analysis of a variety, 
 consisting of 100 parts, was made at the request of 
 Mr. Pennant, by Edward Daniel Clarke, LL.D., 
 Professor of Mineralogy in the University of Cam- 
 bridge, and published in the fourth volume of The 
 Geological Transactions. We subjoin the process 
 adopted, together with the results ; these afford an 
 admirable example of chemical investigation, adapted 
 to the examination of that description of minerals 
 which forms so prominent a class in the economy 
 of engineering. The specific gravity of the lime- 
 stone (alluded to above), estimated in, pump-water 
 at a temperature of 50 Fahrenheit = 2,670. It 
 is of a dark brown colour, and, when breathed 
 upon,* exhales an earthy odour, denoting the pre- 
 sence of iron oxide, in combination with alumine ; 
 but its colour is owing to bitumen rather than 
 to iron." 
 
 1 . One hundred grains being placed upon red 
 
 * All the shaly limestones may be tested by this method.
 
 113 
 
 hot iron for the expulsion of the water of absorp- 
 tion, were* thereby diminished -fa of a grain. 
 
 2. The remainder being reduced to powder in a 
 porcelain mortar, and exposed to diluted muriatic 
 acid until all effervescence ceased, there remained 
 an insoluble residue of the original dark colour of 
 the limestone, which, when carefully washed and 
 dried, weighed ten grains ; allowing, therefore, for 
 the weight of the carbonic acid and lime, after the 
 expulsion of the water of absorption, 89^ grains. 
 
 3. The supernatant acid used in this experi- 
 ment being decanted, and neutralized by the addi- 
 tion of an alkali, yielded no precipitate of iron to 
 the tincture of galls ; but the prussiate of potass 
 threw down a blue precipitate, upon which, how- 
 ever, no reliance can be placed, as it is well known 
 that the prussiate of potass is not a satisfactory test 
 of the presence of iron when this metal exists -in an 
 inconsiderable proportion. 
 
 4. The ten grains of dark brown powder, men- 
 tioned in No. 2, being collected, washed, and dried, 
 were exposed to the heat of a flame of a candle, 
 urged by the common blow-pipe, when combustion 
 instantly ensued, accompanied by a lambent flame, 
 which continued during some seconds, the powder 
 thereby losing its colour and becoming white ; 
 attended also by a loss of weight, amounting to J- of 
 a grain. Hence it is manifest that the colour is 
 owing to bitumen. 
 
 5. To ascertain the proportion of alumine,
 
 114 
 
 (which, from its chemical combination with silex, 
 remained insoluble in the muriatic acid,) a plan 
 recommended by Mr. Holme was adopted. One 
 hundred other grains of the same limestone were 
 calcined in a platinum crucible, and the loss of 
 weight, owing to the expulsion of the carbonic acid 
 was found to equal 40 T J T grains. 
 
 6. The calcined residuum being placed in muria- 
 tic acid, a solution now took place both of the lime 
 and the alumine, and there remained at the bottom 
 of the vessel only an insoluble portion of pure silex, 
 in the form of a white powder, which, when care- 
 fully washed and dried, weighed -f- of a grain. 
 Deducting, therefore, this weight of the silex from 
 the weight of the silex and alumine, which remained 
 in No. 4 after the combustion of the bitumen, the 
 weight of the alumine is ascertained, which, of 
 course, = 8-j%- grains." 
 
 Thus we have, by the foregoing analysis, as 
 follows : 
 
 Carbonic Acid 
 
 . . 40 10 
 
 8 80 
 
 Silex 
 
 60 
 
 
 60 
 
 Water . 
 
 25 
 
 100 
 
 The valuable property of the mortar prepared 
 from this limestone is owing to the presence and
 
 115 
 
 proportion of alumine, and to its property of rapidly 
 absorbing water. It may be added, that the cement 
 possesses all the properties of the pulvis puteolanus 
 of the Romans.* The following chapter contains 
 observations on the nature and properties of other 
 specimens of British limestone. With respect to 
 the limestone of the continent, the admirable trans- 
 lation of M. Vicat's work, by Captain Smith, and 
 some papers by M. Berthier, translated, and in- 
 serted in the 43rd Vol., N. S., of the Repertory 
 of Patent Inventions, are references of which the 
 student may readily avail himself with considerable 
 advantage. We have now placed before the reader 
 an analysis of the grand divisions of the limestone 
 formations of this country. Each sub-division of the 
 limestone deposit may, however, be found to vary 
 in its component parts, and in its relative situation. 
 In the choice of stone, and in its application, the 
 analysis already given will materially assist any 
 further investigation ; for the rest, observation and 
 experience must decide. 
 
 * An analysis of this substance will be found in the following chapter. 
 
 i2
 
 116 
 
 CHAPTER V. 
 
 ON THE CALCINATION OF LIMESTONE. OBSERVATIONS 
 ON BRITISH LIMESTONES, &c. 
 
 LIME has not hitherto been found in a pure or native 
 state ; but in combination with acids and earths it 
 exists in vast quantities. In order to free it, as much 
 as possible, from carbonic acid gas, water, &c., 
 and to render it fit for the purposes of the arts, the 
 limestone must undergo the process of calcination, 
 or burning. The effect of various degrees of cal- 
 cination upon limestone has been carefully noted 
 by Dr. Bry Higgins,* who, in the year 1775, in- 
 stituted a series of experiments for this purpose. 
 Having ascertained, from the experiments and re- 
 searches of Dr. Black, that calcareous stones, which 
 burn to lime, contain a considerable quantity of 
 acidulous gas, and that this gas, in chemical com- 
 bination with earthy matter, formed the greater 
 
 * " Higgins on Calcareous Cement," 8vo. 1780. Since the publication 
 of this work, the progress of chemical science has been so rapid, and 
 the results of later discoveries have elicited so many new and important 
 facts, that the philosophical deductions of the writer have been thereby 
 rendered obsolete. It must be admitted, however, that the scientific 
 data obtained from several of his experiments are of the highest value ; 
 among these may be instanced the observations (No. 1 to 17) on the 
 calcination of limestone, given in the text.
 
 117 
 
 portion of the mineral known as limestone, he (Dr. 
 Higgins) proceeded to make the following experi- 
 ments, upon a scale sufficiently extensive to attest the 
 value of the results. 
 
 " It should be observed, that the difference be- 
 tween chalk lime and the lime obtained from the va- 
 rious limestones chiefly consists in the greater reten- 
 tion or expulsion of the carbonic acid gas contained 
 in them. Specimens of different limestones and chalk 
 were procured and broken into small pieces ; these 
 were burned in close crucibles, lined with lime, to 
 prevent adhesion and vitrification. Similar speci- 
 mens and quantities were also operated upon in 
 perforated crucibles, thereby admitting a free cur- 
 rent of air through them during the firing pro- 
 cess. Specimens, of three pounds in weight each, 
 were also subjected to a distillating process over a 
 graduated fire, in an earthen retort, of a size barely 
 sufficient to hold this quantity. The neck of each 
 retort was lengthened with a conical glass tube, 
 luted on with four parts of lime, one of fine sand, 
 and as much common glue as was sufficient to form 
 a paste. This luting was found impervious, and in 
 every way sufficient for the success of the experi- 
 ments. The extremity of the glass tube was im- 
 mersed in mercury, and by inverting a bottle filled 
 with mercury over the extremity of the tube, what- 
 ever water or gas was expelled from the calcareous 
 matter by the action of the fire was carefully col-
 
 118 
 
 lected and measured. The following observations 
 were deduced from the foregoing processes : 
 
 " 1. Limestone or chalk heated to redness only, 
 in a covered crucible, or in a perforated crucible, 
 through which the air circulates freely, loses about 
 one-fourth of its weight, however long this heat be 
 continued. The sort of lime so formed effervesces 
 considerably in acids, slakes slowly and partially 
 to a powder, which is not white, but is gray or 
 brown, and heats but little in slaking. 
 
 " 2. Limestone or chalk, exposed to a heat barely 
 sufficient to melt copper, whether in a perforated 
 crucible or otherwise, loses about one-third of its 
 weight in twelve hours, and very little more in any 
 longer time. This lime effervesces but slightly in 
 acids ; it heats much sooner and more strongly than 
 the foregoing when water is sprinkled on it, and it 
 slakes more equally, and to a whiter powder. In 
 a variety of trials this lime appeared to be in the 
 same state with the best pieces of lime prepared 
 in the common lime-kilns ; for the quantities of 
 acidulous gas obtainable from both by a stronger 
 heat, or in solution, were nearly equal. They slaked 
 in equal times, with the same phenomena, and to 
 the same colour and condition of the powder. 
 
 " 3. Lime burned in perforated crucibles, or in the 
 naked fire, is whiter than that burned in common 
 crucibles; in which case the air has not so free 
 access to it, although the loss of weight be the same
 
 119 
 
 in both; but this latter kind of lime, in slaking, 
 affords as white a powder as any other which has 
 lost equally of its weight. 
 
 " 4. When dry chalk or limestone is used, in 
 the process above described for making lime in 
 close vessels, and for examining the matter which 
 is expelled by fire, the quantity of water obtainable 
 from it by heat is so inconsiderable as to deserve no 
 notice in our mensuration of that matter. 
 
 " 5. Chalk or limestone heated gradually in 
 these close vessels, loses very little acidulous gas 
 until it begins to redden ; after this the elastic fluid 
 issues from it the quicker as the heat is made 
 greater, and continues to issue until the retort 
 glows with a vivid white heat, sufficient to melt 
 steel. 
 
 " 6. Forty-eight ounces of chalk yield twenty- 
 one ounces of elastic fluid, the first portions of 
 which are turbid as they issue, but soon become 
 clear, without loss of bulk, by the condensation of 
 the watery vapour ; the remaining portions issue 
 transparent and invisible. 
 
 " 7. The residuary lime of forty-eight ounces 
 of chalk, urged with such heat to the total expul- 
 sion of the elastic fluids, weighs only twenty-seven 
 ounces, whilst it is red hot. When it cools it weighs 
 more by reason of the air, which it imbibes as the 
 fire escapes from it. 
 
 " 8. When no more heat is employed than is 
 necessary for the expulsion of these elastic fluids,
 
 120 
 
 the residuary matter is found contracted sensibly 
 in volume, and is good lime, although not so white 
 as lime prepared in the usual way. With water it 
 slakes instantly, grows hissing hot, and perfectly 
 white. The slaked powder is exceedingly fine, except 
 in those parts of the lime which lay in contact with 
 the retort, which are always superficially vitrified, 
 because clay and lime promote the vitrification of 
 each other. 
 
 " 9. The lumps of this lime, immersed in lime 
 water, or boiling water, to expel the air which such 
 spongy bodies imbibe in cooling, dissolve in muri- 
 atic acid without showing any sign of effervescence. 
 
 "10. Limestone or chalk, gradually heated in a 
 crucible, or in the bed of a reverberatory furnace, 
 or in contact with the fuel in a wind-furnace, does 
 not become perfectly non-effervescent and similar 
 to the lime last described, in slaking instantly, and 
 growing hissing hot when water is sprinkled on it, 
 until it has, after a strong red heat of six or eight 
 hours, sustained a white heat for an hour or more. 
 
 "11. Limestones heated sufficiently to reduce 
 them to lime, which slakes instantly, with the signs 
 above described, and which is perfectly non-efferves- 
 cent, do not, in general, lose so much of their weight 
 as chalkstone does, under similar treatment. Some 
 limestones lose little more than the third of their 
 weight. Those which lose the most, slake the 
 quickest, and to the finest powder ; and those which 
 lose the least, slake the slowest, and to a gritty
 
 121 
 
 powder, composed of true lime and particles, chiefly 
 gypseous. 
 
 " 12. The quantity of gypsum, or of other 
 earthy matter, in well-burned lime, is discoverable in 
 dilute muriatic acid ; for this dissolves and washes 
 away the lime, leaving the gypsum to be measured 
 when dry, the part of the gypsum which dissolves 
 being too small to deserve any attention. And if 
 any other earthy matter, or any saline matter ex- 
 isted in the limestone, it vitrifies with part of the 
 calcareous matter in the heat necessary for making 
 non-effervescent lime, and is separable by the means 
 last mentioned, and even by a fine sieve, in most 
 instances. 
 
 " 13. When limestone or chalk is suddenly 
 heated to the highest degree above described, or a 
 little more, if vitrifies in the parts which touch the 
 fire vessels, furnace, or fuel, and the whole of it 
 becomes incapable of slaking freely, or acting like 
 lime. Limestone is the more apt to vitrify in such 
 circumstances, as it contains more gypseous or argil- 
 laceous particles, and oyster-shells or cockle-shells 
 vitrify more easily than limestone or chalk, when 
 they are suddenly heated, which may be imputed 
 to their saline matter; for when they are long 
 weathered they do not vitrify so easily. 
 
 "14. The agency of air is no further necessary 
 in the preparation of lime, than as it operates in the 
 combustion of the fuel. 
 
 " 15. Calcareous stones acquire ths properties of
 
 122 
 
 lime in the most eminent degree, when they are 
 slowly heated in small fragments, until they appear 
 to glow with a white heat, when this is continued 
 until they become non-effervescent) but is not aug- 
 mented. The art of preparing good lime consists 
 chiefly in attending to these particulars. 
 
 "16. That lime is to be accounted the purest 
 and fittest for experiment, whether it be the best for 
 mortar or not, which slakes the quickest, and heats 
 the most in slaking; which is finest and whitest 
 when slaked ; which, when wetted with lime-water, 
 dissolves in muriatic acid or distilled vinegar with- 
 out effervescence, and leaves the smallest quantity 
 of residuary undissolved matter. 
 
 "17. The quick slaking, the colour of the 
 slaked powder, and the former acid, are the most 
 convenient, and, perhaps, the best tests*of the purity 
 of lime. The whiteness denotes the lime to be freed 
 from metallic impregnation, the others show any 
 imperfections in the process of burning, and the 
 heterogenous matter inseparable from the calcareous 
 earth by burning." 
 
 The results of the foregoing experiments are, 
 perhaps, of greater importance to the scientific expe- 
 rimentalist than to the practical lime burner. The 
 calcination of limestone in small quantities may be 
 effected with tolerable success and uniformity of 
 operation in the laboratory ; but, on a comparison 
 with the effects produced by the more extended 
 operations of kiln-burnings, certain anomalies present
 
 123 
 
 themselves, which (as yet) have not been satisfac- 
 torily explained. Before adverting more particu- 
 larly to these, we proceed with a description of the 
 various kilns (suited to particular districts), and best 
 adapted for the calcination of limestone on an exten- 
 sive scale. 
 
 Several attempts have been made to economise 
 the calcination of limestone by the simultaneous pre- 
 paration or manufacture of other materials that 
 required the agency of heat. We may particularly 
 instance the manufacture of coke, and the operation 
 of brick-burning in conjunction with lime-burning. 
 
 The first of these contrivances namely, " a 
 combination of coke-ovens with a lime-kiln" was the 
 subject of a patent granted several years ago to 
 Mr. Heathorn, of Maidstone. This gentleman had, 
 for upwards of ten years, been employed in examin- 
 ing and experimenting upon a variety of kilns, and 
 eventually succeeded in constructing a kiln that 
 should prepare coke, at the same time that the lime- 
 stone underwent the process of calcination. 
 
 By this process the whole of the fuel employed 
 is saved by its being converted into coke ; in addi- 
 tion to this, the drawing of the lime may be accom- 
 plished with a facility equal to that of a common 
 tunnel-kiln ; the chalk or stone is also calcined so 
 gradually that no refuse is left, and consequently the 
 operation of sifting is dispensed with. Kilns on this 
 construction are in operation at Maidstone, Hack- 
 ney, and at Hastings.
 
 124 
 
 The following description of the kilns, and the 
 mode of working, is derived from an account fur- 
 nished by the patentee, and inserted in the " Re- 
 gister of Arts and Journal of Patent Inventions."* 
 
 " The drawing, Fig. 1, Plate 10, represents a 
 vertical section of the lime shaft and coke-ovens ; A A 
 are the side walls (about four feet in thickness), of a 
 rectangular tower, the internal space being filled 
 with limestone from the top to the iron bars, B B, 
 at bottom, whereon the whole column rests. The 
 limestone is raised in a box D, or other proper re- 
 ceptacle, to the top of the building, by means of a 
 jib and crane, E, or other tackle, which is fixed at 
 the back of the tower, together with a platform pro- 
 jecting from beyond the walls, for affording security 
 and convenience for landing. When the limestone 
 is raised as represented, the jib is swung round, and 
 the lime box tilted, by which the whole contents are 
 thrown into the shaft. 
 
 " The coke-ovens, of which there may be two, 
 or a greater or lesser number, according to the mag- 
 nitude of the works, are constructed and arranged 
 in connexion with the lime shaft, in the same man- 
 ner as the two represented in the drawing at F F. 
 These ovens are supplied with coal through iron 
 doors in the front wall (not seen in the section), the 
 doors have a long and narrow horizontal opening in 
 the upper part of them to admit sufficient atmo- 
 
 * No. 91, Vol. iv., pp. 290-91.
 
 H EATHO R N'S KILN 
 
 U KSH t * t * I 1-N. 
 
 SCOTT ISM K I Ul 
 
 FOR CAL.CIt|INC LIMESTONE
 
 125 
 
 spheric air, to cause the combustion of the bituminous 
 or inflammable part of the coal ; the flames pro- 
 ceeding from thence pass into the lime shaft through 
 a series of lateral flues (two of which are brought 
 into view at G G), and the draft is prevented from 
 deranging the process in the opposite oven by the 
 interposition of the partition wall, H, which directs 
 the course of the heat and flames throughout the 
 whole mass of the lime ; the lowermost and prin- 
 cipal portion of which attains a white heat, the upper 
 a red heat, and the intervening portions the inter- 
 mediate gradations of temperature. 
 
 " When the kiln is completely charged with 
 lime, the openings in front or beneath the iron bars, 
 at I I, are closed and barricaded by bricks, and an 
 iron cased door, which is internally filled with sand, 
 to effectually exclude the air, and to prevent the 
 loss of heat by radiation. 
 
 " Therefore, when the kiln is at work, no atmo- 
 spheric air is admitted but through the narrow aper- 
 tures before mentioned in the coke-oven doors. 
 When the calcination of the lime is completed, the 
 barricades at I I are removed, the iron bars at B B 
 are drawn out, by which the lime falls down and 
 is taken out by barrows. It sometimes happens, 
 however, that the lime does not readily fall, having 
 caked or arched itself over the area which incloses 
 it, in which case a hooked iron rod is employed to 
 bring it down. To facilitate this operation inevery 
 part of the shaft, where it may be necessary, a series
 
 126 
 
 of five or six apertures, closed by iron doors, are 
 made at convenient distances from the top to near 
 the bottom of the shaft : two of these are brought 
 into view at K K, where their utility is made appa- 
 rent in the drawing. Two similar apertures are 
 shown in section at the coke-ovens at L L, which are 
 for the convenience of stoking or clearing out the 
 lateral flues, G G, from any matter that might ob- 
 struct the free passage of the flames and heated air. 
 
 " When the coals have been reduced to coke, 
 the oven doors in front (not shown) are opened, and 
 the coke taken out by the peel iron, the long handle of 
 which is supported by a swinging jib, that acts as a 
 moveable fulcrum to the lever or handle of the peel, 
 and thus facilitates the labour of taking out the 
 contents of the oven." 
 
 The combination of a brick-kiln with a lime- 
 kiln is suited to particular districts, where coals are 
 scarce, or where economy is much studied. The 
 combustibles employed are faggots or furze, &c. ; 
 and when limestone is thus calcined, it is techni- 
 cally termed " flare " or " flame burnt." 
 
 The construction of these kilns is as follows : 
 If they are built independent of any other support, 
 the walls should be from four to five feet in thick- 
 ness, and the face of the work made to batter up- 
 wards. In external appearance, they are in the 
 form of a truncated pyramid, whose base externally 
 measures between twenty and thirty feet, and the 
 altitude about fifteen feet. The furnaces of the kiln
 
 127 
 
 consist' of several arched openings (the number 
 varying with the size of the kiln) ; these openings 
 extend from the front to the rear, and are arched 
 throughout with large loose pieces of the lime- 
 stone intended to be burnt. Upon the crown of 
 the arches the limestone is now heaped up to the 
 height of eight or more feet, and upon the top are 
 laid from fifteen to twenty thousand of new un- 
 burnt bricks. When the kiln is about to be fired, 
 small quantities of fuel are placed under the arches, 
 and the external openings are then bricked up nearly 
 to the top sufficient room only being left to add to 
 the fuel as occasion may require. 
 
 A kiln of the above form and dimensions will 
 calcine the whole of the limestone (about 120 quar- 
 ters), and burn the bricks in the space of forty 
 hours.* 
 
 All permanent or perpetual draw-kilns should 
 be well dried by fire, previously to their being em- 
 ployed for burning the lime. The great heat to 
 which they are subjected renders this precaution 
 necessary to prevent their premature destruction by 
 expansion.f 
 
 The practice adopted in some parts of Scotland 
 for the calcination of limestone, is by means of a 
 
 * See Wild's Instructions to Emigrants : a work containing much 
 valuable information on the subject of economical building. 
 
 t A recent examination of a furnace for reducing iron ore, at 
 Staveley, near Derby, showed an expansion of nearly eighteen inches. 
 The furnace is built of brick, and similar to a lime-kiln in form ; the 
 diameter at the widest part outside is about seventeen feet.
 
 128 
 
 kiln constructed according to the drawing "Fig. 2, 
 plate 10. This kiln is a modification of one called 
 " Booker's kiln," and is considered by competent 
 judges to be superior to most others where coal or 
 other smoky fuel is employed. A particular account 
 of the kiln has appeared in the Gardener's Maga- 
 zine, from the communication of C. J. S. Monteath, 
 Esq., a gentleman wh^fcas had extensive experience 
 in the quarrying and burning of lime. 
 
 The following remarks, extracted from Mr. 
 Monteath's paper, apply more particularly to the 
 arrangements and proportions to be attended to 
 in its construction : 
 
 " The kiln is built in a similar situation to 
 ' Booker's kiln ' (on the side of a bank) ; is of an 
 oval form, and thirty-five feet in height ; the dia- 
 meter at the bottom, next the fuel chamber, is only 
 twenty -two inches; but gradually extends, till, at 
 the height of twenty feet, it is five feet ; which di- 
 mension is continued to the top, where the oval 
 (ellipse) is nine feet by five. There is an arched 
 cover to the top (as represented in the drawing), 
 mounted on small wheels, and is drawn off and on 
 by windlasses H H, and has two small openings 1 1, 
 serving as chimneys for the exit of the smoke. 
 
 " As the fuel chamber to this kiln is very broad 
 in proportion to its depth, three separate doors or 
 openings are : found necessary, as well as advanta- 
 geous, for 'more speedily and easily drawing out 
 the lime. In some cases, instead of a moveable
 
 129 
 
 cover, a permanent roof of masonry may be adopted, 
 which should have proper openings to admit the 
 supply of lime and fuel (closed by sliding shutters 
 or hinged doors), while on the roof there should be 
 a chimney for the escape of the smoke. 
 
 " The chief use of a cover, whether fixed or 
 moveable, is, of course, to retain the heat ; but where 
 it is a fixed structure, and sufficiently large, some- 
 thing will be gained by placing the fuel and lime- 
 stones there, to be dried and heated before they are 
 thrown into the kiln. Three-fifths of the ' close- 
 burn oval kiln may be drawn out every day ; and 
 when it is closed at top and bottom, the fire will not 
 go out for five or six days." 
 
 Yorkshire Lime Burning. 
 
 Yorkshire abounds in a variety of limestones ; 
 some of them being particularly fitted for the pur- 
 poses of agriculture (such are those obtained from 
 the southern edge of the eastern moorlands), and 
 others no less excellent for building purposes, 
 namely, the limestones of Brodsworth, Roach 
 Abbey, and adjacent places. 
 
 In a country possessing such an abundant sup- 
 ply of this mineral, and where its use and exporta- 
 tion are so extensive, it may be readily supposed 
 that efficient means for its calcination have not 
 been forgotten. The drawings, figs. 3, 4 X 5, plate 10,
 
 130 
 
 exhibit the construction of the Yorkshire lime-kilns. 
 The fuel used in these kilns consists of small coal 
 interstratified with the limestone. 
 
 A correspondent in the Mechanics' Magazine, 
 a resident in the county (vol. vii. p. 178), observes, 
 that in fixing on a place to build a kiln, the side 
 of a hill, near the rock from which the limestone 
 is obtained, should be chosen. The operations of 
 the workmen are commenced by excavating a suffi- 
 cient space to receive the back of the kiln ; in erect- 
 ing the shaft, two walls are to be carried up with a 
 space between them. The vacuity is to be filled 
 with " small rubble" (or sand) in order to prevent 
 the radiation of heat, and the inner wall must be 
 faced with a grit stone facing, about a foot or 
 eighteen inches wide. This stone will stand an in- 
 tense heat ; when repairs are required, the wall in 
 the rear prevents the materials from falling in. 
 
 The cost of the kiln, built according to the 
 drawings, will not exceed 30Z. Fig. 3 is an eleva- 
 tion of the kiln built against the limestone rock. 
 Fig. 4, plan of ditto, and fig. 5 represents a section 
 through the centre of the kiln. The various de- 
 tailed dimensions are annexed to the drawings. 
 
 The reader will observe that the construc- 
 tion of the above kiln is similar to the furnaces 
 employed for reducing iron ore, in some parts of 
 Derbyshire. 
 
 In certain districts of Yorkshire, Shropshire, 
 Wales, and Scotland, where lime is required for ma-
 
 FIG 3 
 DORKINC LIME. KILN
 
 131 
 
 nure, a singular practice prevails of calcining the 
 limestone without the use of kilns. The limestone 
 is calcined according to the method usually adopted 
 for preparing charcoal. The stone is taken in large 
 pieces, placed in a cavity in the ground, and heaped 
 up in a conical form (called coaks), and, to retain 
 the heat and flame, is covered over with sods and 
 earth. 
 
 Dorking has been long celebrated for the qua- 
 lity of its lime. It has been for many years exten- 
 sively employed in and about London for works, 
 which at least have acquired the reputation of being 
 constructed with the most approved materials. 
 
 One of the most extensive establishments for 
 quarrying and burning this lime, is that of Messrs. 
 Bothwell, situated at Dorking, on the spot where 
 some of the best rock chalk is to be obtained. The 
 arrangement of the kilns differs materially from those 
 already described (see plate 10). Through the kind- 
 ness of the proprietors, we are enabled to give the 
 drawings of one of these kilns (see plate 11), which 
 is of excellent construction, and found to answer the 
 purpose in the most efficient manner. 
 
 Fig. 1 (plate 11) represents the elevation of the 
 kiln. Fig. 2 is a longitudinal section of the same, 
 (taken through the throat and furnace?) and fig. 3 
 represents the ground plan. The several dimen- 
 sions and references are subjoined, in order to render 
 the construction more intelligible and available to 
 the engineer. 
 
 K2
 
 132 
 
 The limestone of Ireland is, for the greater part, 
 crystalline much of it, in fact, being marble, of ex- 
 cellent quality. The form of the Irish permanent 
 kilns is generally that of the " egg placed upon its 
 narrower end, having part of its broader end cut off." 
 The compact texture of the limestone requiring con- 
 siderable heat for its calcination, this form has been 
 adopted, and is said to possess the following advan- 
 tages : 
 
 1st. "The upper part of the kiln being con- 
 tracted, the heat does not fly off so freely as it does 
 out of a spreading cone. 
 
 2nd. " That when the cooled lime is drawn out 
 at the bottom of the furnace, the ignited mass, in the 
 upper parts of it, settles down, freely and evenly, into 
 the central parts of the kiln ; whereas, in a conical 
 furnace, the regular contraction of its width, in the 
 upper as well as the lower parts of it, prevents the 
 burning materials from settling uniformly, and level- 
 ling downward. They 'hang' upon the sides of the 
 kiln, and either form a dome at the bottom of the 
 burning mass, with a void space beneath it, thereby 
 endangering the structure, if not the workmen em- 
 ployed ; or, breaking down in the centre, form a fun- 
 nel, through which the unburnt stones find their 
 way to the draft holes. The contraction of the lower 
 part of the kiln has not the same effect ; for, after 
 the fuel is exhausted, the adhesion ceases, the mass 
 loosens, and, as the lime cools, the less room it re- 
 quires. It therefore runs down freely to the draft 

 
 133 
 
 holes, notwithstanding the quick contraction of the 
 bottom of the kiln or furnace. 
 
 Lastly, " That with respect to the lime furnace, 
 the fire requires to be furnished with a regular sup- 
 ply of air. When a kiln is first lighted, the draft- 
 holes afford the required supply. But after the fire 
 becomes stationary in the middle, or towards the 
 upper part of the kiln (especially of a tall kiln), 
 the space below is occupied by burnt lime, and the 
 supply from ordinary draft-holes becomes insuffi- 
 cient. If the walls of the kiln have been carried up 
 dry or without mortar, the air finds its way through 
 them to the fire. 
 
 " In large deep kilns that are built with air-tight 
 walls, it is common to form air-holes in their sides, 
 especially in front,, over the draft-holes. But these 
 convey the air, in partial currents, to one side of 
 the kiln only, whereas, that which is admitted at the 
 draft-holes passes regularly upward to the centre, as 
 well as to every side of the burning mass ; and, 
 moreover, tends to cool the burnt lime in its passage 
 downward, thereby contributing to the ease and 
 health of the workmen. 
 
 " Hence it is thought that the size of the draft- 
 holes ought to be proportionate to that of the kiln, 
 and the size of the stones taken jointly (air passing 
 more freely among large, than among small stones), 
 and that the required supply of air should be wholly 
 admitted at the draft-holes. By a sliding or a 
 shifting valve, the supply might be regulated, and
 
 134 
 
 the degree of heat be increased or diminished at 
 pleasure."* 
 
 In opposition to the foregoing recommendations, 
 it is held that, although a (partial) reverberation is 
 effected, the opening at the top of the kiln is suffi- 
 ciently large to admit of a great escape of heat. But, 
 admitting that a sufficient reverberation takes place 
 to throw back the heat upon the limestone, it also 
 throws back the carbonic acid gas which it is the 
 main object of the calcination of the limestone to 
 expel ; add to which, the uninflammable nature of 
 the gas alluded to serves to extinguish the flame. 
 
 If, in other respects, a trifling advantage may 
 appear, we feel persuaded that the difficulty expe- 
 rienced by the workmen, in attempting to clear the 
 hollow sides of an oval or elliptical kiln, will prove 
 fatal to their general employment.^ Irish kilns are 
 filled with alternate layers of turf and limestone, of 
 two feet and one foot in thickness, and are fired by 
 igniting the turf at the bottom. 
 
 The only observation of general importance, 
 made by lime-burners, is, that the quantity of stone 
 calcined with a given quantity of fuel depends upon 
 the quality of that fuel. Lime-kilns have, accord- 
 ingly, been constructed with greater regard to the 
 quality of the fuel employed, than to the nature of 
 
 * Nicholson, Arch. Diet. Art. "Kiln." 
 
 f A drawing of a kiln of the figure alluded to above is given in 
 Captain Smith's translation of " Vicat on Cements," and is there in- 
 stanced as " a bad form of kiln:' See plate 1, fig. 9, of that work.
 
 135 
 
 the stone to be calcined, or the operation of different 
 descriptions of fuel upon the various species of lime- 
 stones, during the period of their calcination. 
 
 Captain Smith observes, " That the effects of 
 calcination are not confined to driving off the water 
 of crystallization and carbonic acid from compound 
 limestones; it further modifies the constituent oxides, 
 one by the other. In fact, if we treat an argillaceous 
 carbonate of lime by a weak acid, it forms a deposit 
 more or less abundant. After calcination, on the 
 contrary, a complete solution is effected ; the clay, 
 therefore, has entered into combination with the 
 lime." 
 
 The important fact pointed out by Dr. Gilby, 
 relative to the variety of character exhibited in the 
 same mass of limestone rock, or in contiguity there- 
 to, induces us to express a doubt of the possibility of 
 constructing a lime-kiln capable of calcining the 
 whole mass of materials in a perfect manner. It is, 
 probably, owing to the unequal distribution of the 
 constituent parts of the limestone in the same mass, 
 that unburned pieces, dead lime, sub-carbonates, 
 vitrified masses, &c., are formed ; for it is evident, 
 that, to calcine the whole mass perfectly, the degrees 
 of heat must be as varied as the quality of the ma- 
 terials. When the quality of the limestone is well 
 ascertained, and found to be of uniform character 
 (as in the case of Dorking lime), the experience 
 derived from actual practice will soon point out the 
 necessary temperature required for its proper cal-
 
 136 
 
 cination, and the kind of fuel best adapted for the 
 purpose. 
 
 The calcination of limestone upon scientific 
 principles has been the subject of several English 
 patents ; the following list, obligingly furnished by 
 Mr. L. Hebert,* of Birmingham, will be found 
 extremely valuable to those whose attention may be 
 directed to the further improvement of a process 
 so important to the arts. 
 
 List of English Patents granted for Lime Burning. 
 
 When granted. Name of Patentee. Nature of Patent. 
 
 July 5, 1796 Close Improved Lime Kiln. 
 
 Oct. 3, 1796 Pepper, Jun. . . . Ditto ditto 
 
 July 20, 1801 Stanhope .... Ditto Burning. 
 
 Feb. 13, 1809 Grellier Ditto Kiln. 
 
 May 9, 1809 Brooker Erecting Lime Kilns. 
 
 May 19, 1818 Leger Lime Burning. 
 
 June 1, 1819 Geldart Heating Kilns. 
 
 Oct. 7, 1824 Benecks .... Making Lime. 
 
 Nov. 17, 1824 Heathorn .... Improved Lime Kiln. 
 
 June 6, 1825 Apsden Making Lime. 
 
 In order to point out the nature and peculiari- 
 ties of some of the most important limestones indi- 
 genous to this country, we subjoin the following par- 
 ticulars, which have been deduced from actual expe- 
 riment. The various specimens were procured on 
 the spot, and each chosen as ordinary examples of 
 the kind to which they refer. 
 
 Inventors and patentees may consult a complete and valuable 
 register of all the patents which have been granted since the passing 
 of the Patent Laws, by application, at Mr. Hebert's Office, No. 12, 
 Staples Inn. The author is happy to bear testimony to the great 
 talent and integrity of Mr. Hebert as an Engineer and Patent Agent.
 
 137 
 
 OBSERVATIONS ON VARIOUS BRITISH LIMESTONES 
 ACTION OF ACIDS THEREON, &c. 
 
 Dorking Limestone (Chalk). 
 
 This limestone consists of an indurated chalk 
 marie (clay and chalk) of a dull gray colour, is 
 opaque, and in minute soft grains. When treated 
 with muriatic acid previous to calcination, it effer- 
 vesces violently, and deposits a considerable quantity 
 of clay (according to Smeaton, one-seventeenth part 
 of its weight). After calcination it is light, friable, 
 and of a yellowish tinge. If calcined sufficiently, 
 and immersed in dilute muriatic acid, the whole 
 is taken up, or held in solution. 
 
 This limestone is more or less intermixed with 
 extraneous matter, depending upon the nature or 
 peculiarity of the adjacent strata. Thus, the chalk 
 limestone at Greenhithe, Gravesend, and Dover, is 
 associated with flint ; that at Mersham and Dorking 
 with clay, sand, and a description of sandstone. 
 
 Some ordinary specimens of Dorking lime, 
 taken from Messrs. Bothwell's kilns, and slacked 
 soon afterwards into a paste, formed a light cream-
 
 138 
 
 coloured tenacious mixture, slightly effervescent with 
 acid. The lime evolved great heat in slacking, and 
 rapidly fell to powder. When the Dorking lime- 
 stone is reduced from the state of a carbonate to 
 that of lime, by calcination, it should be used imme- 
 diately, in consequence of its falling to powder by 
 exposure ; its strength is much impaired thereby, 
 and more lime is required for its conversion into 
 good mortar. 
 
 The peculiar fitness of Dorking lime for the 
 ordinary purposes of building is noticed further on. 
 
 Kentish Mag (Green Sand formation). 
 
 This stone is to be found abundantly in the 
 Weald of Kent, Surrey, Sussex, &c. It is com- 
 pact, hard, and of a dark gray colour; effer- 
 vesces violently in dilute muriatic acid,* and 
 deposits a considerable portion of sand after the 
 lime has been taken up by the acid. The greater 
 part of the sand is large, and in transparent, 
 colourless, and angular grains. It is interspersed, 
 however, more or less, with green and red particles, 
 of a silicious nature. After the effervescence the 
 acid remains turbid. 
 
 * In all these examinations the author has employed dilute muriatic 
 acid as the solvent, and the products were examined with the micro- 
 scope. Each specimen, before its dissolution, was about the size of a 
 hazel nut.
 
 139 
 
 This stone forms a pleasing ornamental ma- 
 sonry when properly displayed. It is durable, and 
 forms excellent quoins for flint walls. 
 
 In the county of Kent, a cubic yard of this 
 stone is called a cord. It requires twenty cords of 
 stone to form a rod. The rod = 272^ feet super 
 one foot thick. This masonry requires one hundred 
 of lime and two yards of sand to the rod. Value 
 per rod 13/. Worked quoins are of the value of 
 Is. 6d. per foot, labour only. 
 
 Portland (Oolitic). 
 
 This stone is procured from the Isle of 
 Portland. Similar varieties are also procured 
 at Tisbury (Wiltshire), and Aylesbury (Bucks). 
 The Portland stone effervesces violently in muriatic 
 acid, and deposits a small portion of very sharp 
 fine-grained transparent sand. After the effer- 
 vescence has ceased the acid is left tolerably clear. 
 Portland stone chiefly consists of small egg-shaped 
 particles of carbonate of lime closely connected 
 together, and of a dull white or gray colour. After 
 the fire, in 1666, the quarries in the Isle of Port- 
 land were extensively worked, and supplied stone 
 for the masonry of nearly all the buildings erected 
 by Wren, and subsequent architects. 
 
 The employment of Portland stone for building 
 has decreased materially within the last quarter of
 
 140 
 
 a century. It has been superseded by Bath stone, 
 another of the oolitic series, which we shall presently 
 notice. The action of the atmosphere upon Port- 
 land stone is very destructive, in consequence of the 
 more soluble parts of the carbonate of lime becom- 
 ing decomposed under its influence. The organic 
 remains with which the stone abounds are conse- 
 quently loosed from their matrix and fall out. The 
 internal structure of the stone, becoming exposed, is 
 now attacked, and rapid decay follows. In London, 
 the effect of the atmosphere upon Portland stone is 
 in other respects very remarkable. The projections 
 of cornices, soffits, throatings, carvings, &c., are, in 
 the interval of a few years, coated with a black sta- 
 lactical substance, giving that dingy appearance 
 so often remarked as being peculiar to the public 
 buildings of the metropolis. Upon testing a quan- 
 tity of this substance with muriatic acid, a strong 
 effervescence took place, leaving a considerable 
 residuum of carbonaceous matter. We offer the 
 following as the most probable cause of this phe- 
 nomenon : 
 
 To a certain height, the atmosphere of London 
 is strongly impregnated with carbonic acid gas, and 
 also carbonaceous matter floating therein ; the for- 
 mer, being carried up in a heated state from the 
 numerous fires, &c., combines with the water (particu- 
 larly in the case of rain) of the atmosphere, and is 
 thrown by the wind, &c., against the buildings.
 
 141 
 
 Now it is known that water containing carbonic 
 acid gas becomes a solvent for carbonate of lime, 
 consequently when the impregnated water settles, a 
 slow decomposition will take place, and the loosened 
 and undissolved particles of the stone, accompanied 
 with the- carbonaceous matter, will flow down the 
 weatherings, &c., and settle upon the lower edges 
 and surfaces of the ornamental or other projections, 
 when it is dried, and forms the black mouldering 
 substance above alluded to. To strengthen the fore- 
 going supposition, we may remark, that in propor- 
 tion to the height of the building, so are these effects 
 more or less observable ; the more lofty buildings, 
 such as church towers, &c., being comparatively 
 free from the black substance, near their summits, 
 but increasing as we approach the level of the house 
 tops. A few years ago, an attempt was made by 
 Mr. Henning, the sculptor and medallist, to protect 
 exposed specimens of sculptured masonry, by coating 
 the stone with a peculiar composition (we think it 
 was wax and oil). How he succeeded we are unable 
 to say, but are certain that an effective composition 
 for the above purpose would prove of incalculable 
 value in staying the rapid progress of decay, to 
 which all buildings, constructed with limestone 
 masonry, are particularly liable in this humid and 
 changeable climate.
 
 142 
 
 Bath Stone (Oolitic). 
 
 The following varieties of Bath limestone are 
 oolitic in their structure, and are carbonates of lime, 
 having but little extraneous matter. 
 
 The whole of the series consist of minute egg- 
 shaped grains of carbonate of lime, imbedded in a 
 matrix of a softer nature, in which is mixed an 
 immense number of very small comminuted shells. 
 
 Farley Down Stone. Cream-coloured, effer- 
 vesces violently in acid, and leaves a dark-coloured 
 residuum. After effervescence the acid is left turbid, 
 and of a dark yellow colour. It is unfit for damp 
 situations, such as plinths. 
 
 Box Scalit, No. 1.- Lighter coloured than 
 Farley Down Stone effervesces strongly, and leaves 
 little residuum. It contains small crystals of carbo- 
 nate of lime. This stone is unfit for exposure. 
 
 Box Scalit, No. %. Cream-coloured, coarsely 
 oolitic, strongly effervescent, and leaves little resi- 
 duum. Unfit for exposure. 
 
 Box Corn Grit. Cream-coloured, coarsely 
 oolitic, intermixed with larger particles of shells 
 effervesces strongly, leaves no residuum. This stone 
 is adapted for works above ground. 
 
 Box Ground Stone. Coarsely oolitic (some 
 oolitic particles being much flattened), dark cream-
 
 143 
 
 colour, effervesces strongly, leaves more residuum 
 than the others. This stone is a good weather stone. 
 
 Coombe Down Stone. Coarsely oolitic, darker 
 colour than the above, with small shining crys- 
 tals of carbonate of lime. This stone effervesces 
 strongly, and leaves little residuum. It is a good 
 weather stone. 
 
 In addition to the foregoing specimens, pro- 
 cured from the quarries, another specimen was exa- 
 mined, but with very different results. This speci- 
 men was obtained by the author, at Worcester, 
 during the present summer (1838). It is a frag- 
 ment from a block of Bath stone, which was being 
 prepared for the restoration of the pinnacles at the 
 eastern front of the Cathedral. The stone bears 
 every resemblance to the Box Corn Grit ; it effer- 
 vesces strongly, but deposits a considerable number 
 of oolitic particles, perfectly insoluble. These parti- 
 cles, when examined with the microscope, were 
 observed to be of a yellow colour, semi-transparent 
 (in the moist state), and sufficiently tender to be 
 crushed by a fine steel point. In the dry state the 
 same particles were opaque and white. Another 
 piece of the same stone gave the former residuum, 
 with the addition of a few grains (apparently) of 
 silex. The action of acid on the oolitic grains 
 of the carbonate indicated that the grains con- 
 sisted of two or more concentric layers of lime, 
 as it could be distinctly perceived that each layer
 
 144 
 
 was, in its turn, attacked by the acid. Whether 
 each of these grains have a nucleus, or whether 
 some are only hollow, we have not, as yet, been able 
 to determined 
 
 To ascertain the cause of the form and deposit 
 of oolitic particles in limestone, is a subject well 
 worth the serious attention of the practical chemist. 
 The investigation of this subject might probably 
 serve to account for the production of boiler balls 
 in some steam-engine boilers.* 
 
 Brodsworth .Limestone (Oolitic). 
 
 Brodsworth Stone. This limestone is procured 
 from Brodsworth, in the county of York, 5J miles 
 from Doncaster. It is a tender limestone, of a light 
 cream colour, works to a good face, and forms good 
 ornamental masonry. In its internal structure, it 
 approaches to the soft powdery appearance of chalk, 
 but is slightly oolitic. It effervesces violently in 
 acid, leaves little residuum, the acid is left turbid, of 
 a dark yellow colour, with a scum floating on the 
 surface. 
 
 * For a description of these remarkable deposits, see " Armstrong 
 on Steam Boilers," Part iii., pp. 77-8.
 
 145 
 
 Purbeck (Wealden Group). 
 
 Purbeck. A very compact, smooth-grained 
 calcareo-silicious stone, effervesces in acid, and 
 yields a considerable quantity of mixed sand, 
 namely, rounded and angular. The sand is varied 
 in colour, being composed of brown, green, and 
 transparent grains, the latter particles being the most 
 numerous. After effervescence the acid remains 
 tolerably clear. This stone is practically so well 
 known that its uses need not be pointed out. 
 
 , Lias, from near Bath. 
 
 Colour, dark gray, effervesces strongly in acid, 
 depositing a dark-coloured clay. The solution con- 
 tains much iron, is very turbid, and of a dark green 
 colour. A few hard black grains of a metallic 
 lustre remain refractory in the liquid. 
 
 No. 2. A very compact specimen of lias, from 
 near Stoke Prior, Worcestershire, afforded, under a 
 similar examination, corresponding results. Many 
 specimens of the lias limestone form a very durable 
 masonry. The pedestal of the great chimney shaft 
 at the British Alkali Works, at Stoke Prior, is built 
 with this kind of stone. The pedestal is 75 feet 
 in height, 36 feet diameter at the base or plinth, 
 and 32 feet diameter above the plinth, which 
 L
 
 146 
 
 is ten feet six inches in height. The whole height 
 of the shaft is 308 feet. 
 
 Septaria* from the London Clay, 
 
 May be properly classed among the hydraulic 
 limestones indigenous to this country. It consists 
 of " ovate or flattish masses of argillaceous lime- 
 stone," arranged in nearly horizontal layers, chiefly 
 found imbedded in the London clay. This sub- 
 stance is sometimes coated with a calcareous spar, or 
 sulphate of barytes ; it forms the basis of some well- 
 known hydraulic cements of good quality. A speci- 
 men procured from the excavation of the Primrose- 
 hill Tunnel (London arid Birmingham. Railway), 
 effervesced considerably in dilute acid, and deposited 
 a greater quantity of clay than lias ; the colour was 
 also much darker. 
 
 Roche Abbey stone (carboniferous series) is 
 a compact crystalline limestone,, of a gray colour. 
 It effervesces slowly in acid, without leaving any 
 residuum, and the solution is but little discoloured. 
 This stone works to an excellent face, and forms 
 durable masonry.f 
 
 Previous to the institution of certain experi- 
 ments on water cements, by the late Mr. Smeaton, 
 
 * Also called Sheppy and Harwich Cement Stone, from its be in 
 obtained in considerable abundance at those places. 
 
 t A complete analysis of the principal British limestones will be 
 given when treating of the quality of lime they afford.
 
 147 
 
 an opinion had prevailed among practical men, that 
 calcined chalk produced the weakest lime, in con- 
 sequence of its being obtained from the most tender 
 limestone. 
 
 To prove the truth or fallacy of this opinion, 
 experiments were made with two specimens of lime- 
 stone, apparently of very opposite qualities, the one 
 being a piece of common chalk,* and the other an 
 equal quantity of Plymouth limestone ; the result 
 proved that no perceptible difference existed in the 
 quality of the two limes, but that each was of the 
 same crumbling and weak nature ; satisfactorily 
 proving that the quality of the lime was not owing 
 to the density of the limestone. Succeeding experi- 
 ments, made by the same engineer, established a 
 fact of much greater importance, namely, that pure 
 limestones, or those carbonates of lime which dissolve 
 in acids without residuum, are almost useless for the 
 manufacture of building lime, when compared w.ith 
 those that are alloyed with a certain portion of clay. 
 On the subject of Dorking lime, which has an alloy 
 of this kind, he thus speaks : " From the experiments 
 now related, I was convinced that the most pure 
 limestone was not the best for making mortar, espe- 
 cially for building in water : and this brought to 
 mind a maxim I have learnt from workmen, that 
 the best lime for the land was seldom the best for 
 building purposes; of which the reason now ap- 
 
 Common Chalk is nearly pure. Chalk Marie is a vry< different 
 substance, although belonging to the same geological formation. 
 L 2
 
 148 
 
 peared, which was, that the most pure lime, affording 
 the greatest quantity of lime salts, or impregnation, 
 would best answer the purposes of agriculture : 
 whereas, for some reason or the other, when a lime- 
 stone is intimately mixed with a proportion of clay, 
 which, by burning is converted into brick, it is 
 made to act more strongly as a cement* This 
 suggested to me the idea, that an admixture of clay 
 in the composition of limestone, when treated as 
 above specified, might be the most certain index of 
 the validity of a limestone, for aquatic buildings ; 
 nor has any experience since contradicted it, as all 
 the limestones in repute for water works, that I have 
 met with, have afforded this mark. Even the 
 J)orking lime, much esteemed for those, uses in 
 London, and in the country round about, is plainly 
 nothing but a species of chalk, impregnated with 
 clay, of which it makes full one-seventeenth part of 
 its original weight." 
 
 * The ordinary class of calcareous minerals 
 furnish the following descriptions of lime upon calci- 
 nation : 1. rich lime; 2. poor lime ; 3. slightly hy- 
 
 * It must not be wondered at that workmen generally prefer the 
 more pure limes for building in the air, because, being unmixed with 
 any uncalcareous matter, they fall into the finest powder, and make the 
 finest paste, which will of course receive the greatest quantity of sand, 
 (generally the cheaper material) into its composition, without losing its 
 toughness beyond a certain degree, and requires the least labour to bring 
 it to the desired consistence : hence, mortar made of such lime is the 
 least expensive ; and in dry ivork the difference of hardness, compared 
 with others, is less apparent." Smeat&n's Narrative, fyc. of Eddystane 
 Lighthouse. Fol. Edit. 1793, p. 108.
 
 149 
 
 draulic lime ; 4. hydraulic lime ; and, 5. eminently 
 hydraulic lime. The quality of these limes varies 
 with the proportion of silex, alumen, iron, &c. &c. 
 contained in the stone ; and the quality of the 
 lime is further modified by the degree of calcination 
 to which the specimens are subjected.* Our pre- 
 sent observations are confined to two of the above 
 kinds, namely, the hydraulic lime and the rich 
 lime. 
 
 The annexed series of British limestones -\ are, 
 from the proportion of the alloy in their composition, 
 eminently calculated to produce strong hydraulic 
 lime upon calcination. It will be observed that they 
 are chiefly of the lias species. 
 
 Species of 
 Limestone. 
 
 |* 
 
 Colour of 
 the Clay. 
 
 Reduction 
 of weight 
 by burning. 
 
 Colour of the Brick. 
 
 Aberthaw 
 
 3 
 
 
 4 to 3 
 
 
 Watchet 
 
 2 3 
 3 
 
 Ditto 
 
 , 4 to 3 
 
 
 
 25 
 3 
 
 Ditto 
 
 3 to 2 
 
 Gray stock brick. 
 
 Long B^nnington .. 
 
 14" 
 
 Ditto 
 
 
 
 Dirty blue. 
 
 Sussex Clnnch 
 Dorking 
 
 .1 
 
 Ash 
 Ditto 
 
 3 to 2 
 
 Ash colour. 
 
 Berryton Gray Lime 
 <; uili]t<.rd 
 
 1 T 
 
 TT 
 
 2 
 
 Ditto 
 
 
 
 Sutton (Lancashire) 
 
 1 9 
 ~l~6 
 
 Brown 
 
 
 
 * See also " Vicat" on Mortars and Cements. Translated by Captain. 
 Smith, p. 9. 
 
 t Extracted from Smeaton's Narrative, &c.
 
 150 
 
 Effect of Iron on Calcareous and Silicious Matter. 
 
 Iron appears to be a very active and energetic 
 agent in the formation of natural cements. Its com- 
 bination with some of the calcareous, and nearly all 
 the silicious deposits, exhibits much diversity of cha- 
 racter, and, in many instances, can only be separated 
 by careful analysis, aided by considerable chemical 
 experience. The lias deposit contains iron in con- 
 siderable quantity, but the calcareous rocks above 
 the lias (with the exception of the lower Bath 
 oolite) contain little oxide or carbonate of iron.* 
 In sub-aqueous works, it is highly necessary to in- 
 crease the hydraulic properties of the lime employed, 
 by the admixture of certain substances whose con- 
 stituents will operate energetically upon it. These 
 substances, whether natural or artificial, are termed 
 Puzzolanos* The expense attending the importa- 
 tion of the natural volcanic Puzzolano from Italy, 
 almost prohibits its employment in the engineering 
 works of this country; but several efficient substitutes 
 
 * See " Phillips's Treatise on Geology," vol. i. p. 202. 
 t This mineral is found in the greatest abundance at Puteoli, in 
 Italy (now called Puzzuoli). It is of the lava genus, magnetic, and 
 easily melts per se into a black slag. It suddenly hardens when mixed 
 -with one-third of its weight of lime and water, forming a cement more 
 durable under water than any other. Bergman found one hundred 
 parts of it to contain fifty-five to sixty of silicious earth, twenty of argil- 
 .laceous, five or six of calcareous, and from fifteen to twenty of iron: 
 this last constituent is considered to be the cause of its property of hard- 
 ening under water. The iron decomposes the water of the mortar; and 
 thus, in a very short time, a new compound is formed. Stuart, Arch. Die,
 
 151 
 
 have been discovered, in all of which iron forms a 
 material constituent ; the composition, mode of pre- 
 paration, &c. of these artificial Puzzolanos, will be 
 subsequently adverted to. The admixture of pul- 
 verized forge scales, or iron dross, with calcareous 
 matter, produces a very strong hydraulic mortar. 
 A composition of this kind was used at the works of 
 the Eddystone Lighthouse, and appears to have 
 originated with the Engineer (Mr. Smeaton) from 
 observations incidentally made on the cementing 
 property of iron when disseminated in a gravelly or 
 silicious matrix. 
 
 Having recently witnessed an extraordinary 
 instance of the effects of iron when in contact 
 with silicious matter, we now direct the attention 
 of the reader to the following particulars: The 
 foundations of the piers of Westminster Bridge were 
 originally laid in caissons in the following manner : 
 A massive raft of timber was constructed of a form 
 and size suitable to the pier ; furnished with a bot- 
 tom, ends, and sides, but the ends and sides were 
 secured together in such manner that they might 
 be readily detached from each other when neces- 
 sary : a portion of the pier was erected in this 
 sort of flat-bottomed barge ; and, when ready, 
 water was admitted in order to sink it, the descent 
 being regulated by guide ropes : the load of ma- 
 sonry having been deposited on the bed of the 
 river (previously levelled and prepared to receive 
 it), the sides and ends of the caisson were withdrawn
 
 152 
 
 from the raft to be again used as occasion might 
 require ; the piers were protected externally, around 
 the bases, by permanent piling, driven into the bed 
 of the river, their lower extremities being pointed 
 in the usual manner and shod with iron.* The 
 defective nature of a foundation thus constructed 
 became evident previous to the completion of the 
 structure ; since that period repairs have been fre- 
 quent and extensive, and at the present time some 
 considerable operations of this kind are being effected 
 by Messrs. Cubitt. In the course of the works it 
 became necessary to withdraw some of the fender or 
 sheeting piles, which had been driven into a gravelly 
 substratum, and it was found that their lower extre- 
 mities were coated with a concreted mass of coarse 
 flinty gravel, of extreme density. Upon examining 
 this concretion, we found that the greater portion of 
 the iron with which the feet of the piles were pro- 
 tected had oxidized and combined with the gravel. 
 On fracture, the substance exhibited the same ap- 
 pearance as iron-sand, or stone, when strongly im- 
 pregnated with the metalic oxide : when treated 
 with diluted muriatic acid it effervesced considerably, 
 and evolved an odour similar to sulphuretted hydro- 
 gen; lastly, a pulverized portion of the concrete 
 having been thrown into lime water, restored the 
 solution (lime water) to a pure state. From the 
 foregoing examination, we deduce the following 
 
 conclusions : 
 
 
 
 * See Mechanics' Magazine, vol. xiii. p. 322.
 
 153 
 
 1st. That iron, imbedded in a gravelly and 
 silicious stratum, will oxidize and disseminate its 
 decomposed particles in the surrounding matrix, 
 forming a ferrugino-silicious concrete of extreme 
 density. 
 
 2nd. That a concrete thus formed becomes an 
 energetic artificial Puzzolano, indicated by its effer- 
 vescing with acid and decomposing lime water. 
 
 It is highly probable that the decay of the 
 foundations at Westminster Bridge may have been, 
 in some degree, retarded by the formation of this 
 concrete around the base of the piers, and the 
 pointed end of the piles. 
 
 On the Use of Rich Lime. 
 
 Those limestones which dissolve freely without 
 discolouring the acid, and leave little or no precipi- 
 tate after the effervescence is completed, are gene- 
 rally capable of furnishing rich lime. Calcined 
 shells produce a lime of this description, and we are 
 informed by the author of the " Parentalia," that 
 the mortar used for the " under drawing and inside 
 work" of " St. Paul's Cathedral" was composed of 
 " calcined shells" and produced excellent mortar. 
 This statement induced the late Mr. Smeaton to 
 investigate the quality of " shell lime ;" upon trial, 
 he found it to set hard, and readily, without any 
 admixture of sand, trass, or other matter. In short,
 
 154 
 
 for water work, trass scarcely appeared to improve 
 its natural quality. On being put into water, after 
 it was set, it did not dissolve, but did not acquire 
 additional hardness ; on the contrary, by degrees it 
 macerated and dissolved, not internally, but gradually 
 fro m the surface inwards ; and hence he concluded 
 it totally unfit for use. He was afterwards informed 
 that a part of the work at Ramsgate Pier had been 
 done with this kind of lime, but was subsequently 
 taken up, on its dissolving quality in sea water being 
 discovered.* A recent examination of the principal 
 buildings erected by Sir C. Wren has satisfied the 
 author that, although rich lime was extensively em- 
 ployed in their construction, there yet remains suffi- 
 cient evidence to show that the architect did occa- 
 sionally introduce materials, in conjuction with the 
 mortar, of somewhat remarkable character. 
 
 During the recent repairs of the parish church 
 of St. Vedast, Foster-lane, an opportunity was 
 afforded to institute a minute examination and ad- 
 measurementt of the tower and spire, completed by 
 Sir C. Wren, in the year 1697. In the course of 
 the examination, particular attention was directed 
 to the state and quality of the mortar originally em- 
 ployed in that building. The vertical joints of the 
 masonry composing the spire were considerably 
 
 * Smeaton's Narrative, &c., p. 106. 
 
 t For the kindness of the architect, Mr. S. Angell, in permitting 
 the necessary survey to be made, the author begs to return his sincere 
 acknowledgments.
 
 155 
 
 opened (probably caused by the expansion of the 
 metal cramps), and the mortar was found to be in 
 a weak and crumbling state, but the base of the 
 obelisk terminating the spire, was discovered to be 
 laid on a thick mortar joint in which was imbedded 
 two courses of flat oyster shells: these, together with 
 the mortar, had remained uninjured for nearly one 
 century and a half. 
 
 We are not yet prepared to offer a satisfactory 
 solution of this phenomenon ; the necessary experi- 
 ments will require considerable attention and occupy 
 much time. For the present we refer the reader 
 to the note* at the bottom of the page, in which is 
 
 * " It is remarkable that oysters, and shells which, like them, are 
 composed of distinct broad lamella of alternating membrane and car- 
 bonate of lime, have resisted in almost all rocks, argillaceous, calcareous, 
 arenaceous, the chemical changes to which venerida, trigoniae, and 
 others of an apparently compact texture, have completely yielded. 
 While the former retain their lamella and pearly surfaces, the latter 
 have often been wholly dissolved in limestone rocks, and their places 
 left vacant ; while a cast of the inside of the shell, and an impression 
 of the outside, disclose completely the history of the change. A further 
 process is frequently superadded, by which the cavity is again partially 
 or wholly filled with crystals of carbonate of lime, which has been in- 
 troduced by filtration through the surrounding rock. In other cases, 
 silicious matter, pyrites, and other substances, have passed by a similar 
 process. The common fossil, called belemnites, of the same group as 
 the cuttle, is a remarkable instance of the force of the original struc- 
 ture in controlling the effects of chemical agencies ; for in clay, sands, 
 chalk, flint, limestone, pyrites, this singular fossil generally retains its 
 fibrous structure, colour, translucency, and chemical properties ; while 
 in the same masses echini are changed to calcareous spar, and sponges 
 to flint, and many shells have totally vanished." Phillips'* Geology, 
 vol. i. pp. 78, 79.
 
 156 
 
 contained some observations that may possibly supply 
 data for a further investigation. 
 
 The remarks made by Mr. Smeaton, on the 
 quality of rich lime, have been confirmed by the 
 more recent experiments of M. Vicat; and it is now 
 decided that rich lime is incapable of furnishing a 
 good mortar, and that the admixture of quartzose, 
 silicious sands, or other inert substances so beneficial 
 to hydraulic limes, is positively injurious to rich 
 lime.* 
 
 * Captain Smith states, that the quality of rich lime is much im- 
 proved by adding a small quantity of coarse sugar to the water with 
 which it is to be worked up. (See his Translation of Vicat, note, 
 pp. 84, 85.)
 
 157 
 
 CHAPTER VI. 
 
 ON THE PROPORTION AND ADMIXTURE OF THE INGRE- 
 DIENTS EMPLOYED IN THE COMPOSITION OF ORDI- 
 NARY MORTAR, QUALITY OF SANDS, SANDSTONES, &c. 
 
 AMONG the recent investigations which have 
 materially assisted in promoting a more perfect 
 theory of the consolidation of mortars, those of 
 Professor Fuchs are entitled to hold a prominent 
 place. The various compounds of lime and sand, 
 constituting the materials of common mortar, and 
 the admixture of unslacked lime, with broken 
 stones, ballast, or gravel, forming the basis of the 
 strongest concrete, severally possess certain proper- 
 ties, and exhibit distinct phenomena, referrible to a 
 most important chemical and mechanical combi- 
 nation. 
 
 In the course of his investigations, Professor 
 Fuch's noted certain facts, from which he concluded 
 that the induration of various kinds of mortar de- 
 pended upon the formation of silicates of lime, 
 and sometimes also alumina of silicates. He dis- 
 covered that these silicates retain the water and 
 acquire the hardness of masses of stone, while the 
 hydrate of lime in excess is gradually united with
 
 158 
 
 carbonic acid, so that the indurated mortar may be 
 considered as a compound of carbonate of lime and 
 zeolite. 
 
 Opal, pumice-stone, obsidian, and pitch-stone, 
 simply pulverized, form a good cement with hydrate of 
 lime, while quartz and sand only produce an hydrated 
 silicate upon the surface of each grain. Although 
 the mass is thus connected, it does not readily 
 become solid. If the quartz has been reduced to a 
 fine powder, the more solid will the mass become. 
 Now, if one-fourth part of lime be mixed with the 
 quartz, and the whole be well calcined, so that the 
 mass becomes a frith, and the whole be afterwards 
 pulverized and mixed with one-fifth part of lime, an 
 hydraulic mortar or cement is obtained, which 
 attains a sufficient hardness to admit of being 
 polished. Felspar with lime hardens slowly, and 
 only at the end of five months ; but if calcined with 
 a small quantity of lime it becomes much better. 
 Water abstracts from this mortar six per cent, of 
 potash. Common potter's clay, which is worth 
 absolutely little or nothing when uncalcined, pro- 
 duces, when calcined with lime, a cement which 
 hardens perfectly well, provided it contains only a 
 small portion of iron. 
 
 Professor Fuchs also found that steatite,* which 
 had been heated to a bright red heat, would not 
 combine with lime, and, concluding that magnesia 
 possessed a very strong affinity for silicious acid, he 
 
 *. Soap stone, a sub-species of rhomboidal mica. Ure,
 
 159 
 
 tried the employment of calcined dolomite (magne- 
 sian limestone) for the cement instead of common 
 lime, and found that it greatly surpassed the latter, 
 both for the preparation of common mortar and for 
 that of hydraulic mortar. He also obtained good 
 mortar of the latter kind with calcined marl.* 
 
 The greater number of specifications prepared 
 by surveyors for the erection of buildings, direct 
 that the mortar shall be composed of stone-lime and 
 sharp river-sand, to be mixed in the proportions of 
 one part of lime to three parts of sand. These 
 proportions will make excellent mortar if properly 
 compounded ; but, as the quality of the lime varies 
 considerably, so will it take more or less sand. 
 
 Builders employ two methods of compounding 
 their mortar : First, when it is required to convey 
 it in a dry state to the work, it is done by forming 
 a bed of lime, surrounding it with sand, and then 
 throwing on the lime a sufficient quantity of water 
 to slack it, and covering it up immediately with 
 sand ; after it has remained some time in this state, 
 it is turned over, and, if necessary, screened. The 
 mixture is now in the state of a dry powder, and 
 can be carted to the work, where more water is 
 added and it is chafed up for use. The other 
 method is employed when there is convenience for 
 making it up at the work. In this case it is what is 
 termed " larryed. " Thus : the lime is put into 
 the middle of a bed of sand, and a large quantity 
 
 * See Repertory, 1837.
 
 160 
 
 of water thrown on, and with lime-hoes mixed up 
 immediately until completely incorporated. It is 
 tfyen allowed to remain for a few hours, when it 
 becomes set, and of proper consistency for use. 
 The lime when turned up in this way will admit of 
 a larger quantity of sand, as all the particles of lime 
 are dissolved, whereas by the first method there are 
 always small particles of the lime which cannot be 
 properly mixed, however much it may be chafed 
 up. From observations recently made, it was found 
 that seventy-two bushels of stone-lime required 
 eighteen yards of sand, making good " larryed mor- 
 tar" the cubic contents of which =315 feet. 
 
 Chalk-lime mortar requires two parts of lime to 
 three of sand, and is now chiefly used for plasterers' 
 work. 
 
 The theoretical investigations connected with 
 the composition of mortars have for a considerable 
 period occupied the attention of the most celebrated 
 French chemists. In researches of this nature they 
 are considerably in advance of us ; but the repu- 
 tation of the English builders for practical expe- 
 rience in the manipulation of mortars is, on the 
 other hand, well known and appreciated by all 
 those whose attention has been directed to these 
 important investigations. The professional practice 
 of English architects, relating to the composition of 
 mortars employed in public or other works, is best 
 exemplified by extracts from their original specifi- 
 cations. We subjoin a few, which will show the
 
 161 
 
 relative degree of importance attached by different 
 architects and engineers to this division of their 
 instructions, and the proportions of materials, mode 
 of manipulation, &c., adopted by each. 
 
 Ordnance Works. 
 
 Not less than thirty-nine bushels of lime * to 
 every rod of brick-work. The lime to be slacked 
 under cover, and the mortar made on a stone or 
 brick floor, and properly worked until all the parts 
 are thoroughly incorporated. 
 
 Farm-house and Farmery. Erected at Greenford, 
 1832. 
 
 Good fresh gray lime and river sand properly 
 screened, and in the proportion of one of lime to 
 three of sand, well tempered together. 
 
 Stockport Church, Cheshire. 
 
 Buxton lime (Cheshire) mixed with two-thirds 
 of sand. 
 
 * Thirty-nine bushels of lime equal one hundred and a half of 
 lime, and would require seventy-five bushels of sand to make enough 
 mortar for a road. In the printed contract no distinction is made as 
 to chalk or stone lime.
 
 162 
 
 Bankrupts Courts, Basinghall Street, London. 
 
 The mortar to consist of one-fourth of good 
 Dorking lime, and the remaining three-fourths of 
 clean sharp river sand. 
 
 Turkey Street Bridge, Enfield, 1827. 
 
 The brick-work to be laid in Dorking stone, or 
 blue lias lime mortar, and clean sharp Thames 
 sand, in the proportions of three parts of sand to 
 two of lime-, to be made in a pug-mill and used 
 hot. The grout to be in the same proportions. 
 
 Exeter Higher Market, Devon, 1836. 
 
 Mortar for the brick-work is to be made 
 with well-burnt stone lime (Plymouth) and good 
 clean sharp grit sand, in proportions of one and a 
 quarter to three. The lime is to be thoroughly 
 slacked with an abundant quantity of water as 
 soon as it is brought on the premises, and imme- 
 diately after, well protected from the action of the 
 atmosphere by a thick covering of the ingredient 
 with which it is to be mixed; in this state it is to lie 
 until quite cool, and then mixed together in the above 
 proportions. This mixture is afterwards to be sifted 
 through a wire sieve, and made up with such a quan- 
 tity of water only as will render the compound of the
 
 163 
 
 consistency of damp sand. It is to be well tempered 
 in a pug-mill, and to be laid in heaps from two to 
 three weeks, being protected during this period, so 
 as effectually to prevent it becoming dry or setting. 
 Ultimately it is to be worked up for use. The 
 mortar for the free-stone is to be made up of fine 
 lime putty, and bright coloured fine sharp sand, 
 washed clean, and well tempered together. 
 
 Silk Mill and Engine House for Messrs. Grout, 
 Bay Us, 8f Co., at Great Yarmouth, 1825. 
 
 The mortar for the mill, engine, and boiler 
 house to be composed of the best Dorking lime and 
 sharp sand, in the proportion of three parts of sand 
 to one part of lime. The mortar for the chimney 
 (one hundred feet in height) to be the same as before 
 described, but for the other parts, to consist of one- 
 third part of the best chalk lime (Yarmouth], used 
 fresh from the kiln, and two-thirds of clean sharp 
 sand, well worked together. 
 
 House in Orion's Buildings, Southwark Bridge Road, 
 in the Liberty of the Clink, London. 
 
 Mortar to be composed of Merstham stone lime 
 and sharp drifts and from above London Bridge, in 
 the proportion of one heaped bushel of lime to two 
 striked bushels of sand, well tempered. 
 M 2
 
 164 
 
 Works at the Berkeley and Gloucester Canal. 
 
 The mortar must be made of clean sharp sand 
 and Aberthaw lime (Wales), in the following propor- 
 tions; that is to say, for works under water, and ex- 
 posed to the river Severn in front, two measures of 
 sand to one of lime ; for backing all work under water, 
 and exposed to water, three measures of good sand to 
 one of lime; and for all other backing, four measures 
 of sand to one of lime. 
 
 J J 
 
 The mortar required for the locks and the outer 
 gates of the basin to be intimately mixed in a pug- 
 mill. The limestone is to be brought to the ground 
 and burned upon the site of the works, the contrac- 
 tor having the use of any kilns now thereon ; but he 
 is to erect others if necessary.* 
 
 Greenwich Railway. 
 
 The mortar to be composed of the best Hailing 
 lime and sharp river sand from above London Bridge, 
 in the proportions of one of lime to two and a half of 
 sand. 
 
 London and Birmingham Railway. 
 
 Mortar for all the works near the London sta- 
 tion to be composed of the best burnt Dorking or 
 
 * Blunt's Civil Engineer. Division A.
 
 165 
 
 other lime of equal quality and clean sharp river 
 sand, in the proportion of three of sand to one of 
 lime; the compost is to be mixed in a dry state, and 
 passed through a pug-mill with a proper quantity 
 of water. 
 
 Watford Tunnel. 
 
 The mortar to be used in the tunnel shall be 
 made with the best fresh burnt Merstham or Dor- 
 king lime, or other lime which the Engineer may 
 deem equally good. It shall be ground under edge 
 stones in its dry or unslacked state. The sand must 
 be sharp and clean, and mixed with the lime in the 
 proportion of three measures of sand to one of lime. 
 
 Blisworth Division. 
 
 The mortar to be used in the beds and faces of 
 buttresses, walls, sides, or drains, and invert arch, to 
 consist of one part of lime to three parts of clean 
 river or other unexceptionable sand. The sand to be 
 passed through a quarter-inch screen; the lime to 
 be fresh and well intermixed by a thorough beating. 
 The mortar for running into the upright joints of 
 the courses, and for filling in the work sound, to 
 consist of one part lime to four parts of small un- 
 screened gravel, to be well mixed and beaten to a 
 tough consistency, and liquefied in tubs or other
 
 166 
 
 vessels, to be properly adapted to run into and fill 
 up all vacuities. 
 
 The mortar to be used as hot as is consistent 
 with the safety of the work, and the sand and gravel 
 to be perfectly free from any loamy or other 
 particles of a muddy nature. 
 
 The limestone rock, found in the excavation, 
 may be used for the mortar specified to be used 
 in the retaining walls of this contract. 
 
 The foregoing extracts from the original speci- 
 fications, respecting the composition of mortar, 
 exhibit a tolerable agreement with each other ; and, 
 with the exception that the preliminary directions of 
 some are more copious and explanatory than others, 
 may be considered as affording a concise and satisfac- 
 tory view of the modern practice adopted by some of 
 the most eminent builders and architects, grounded 
 upon careful observation, and great practical expe- 
 rience. The quality of the sand required for the 
 composition of mortar should undergo careful exa- 
 mination, as it operates with considerable influ- 
 ence on the quality of the mortar. 
 
 In districts where sand of the requisite energy 
 and sharpness is unattainable, road-drift has been 
 employed, and, in some instances, recommended 
 in the specification of works. Where the re- 
 pair of roads has been effected with a mixture 
 of good flint and quartz gravel, and the drift 
 thoroughly screened to separate the muddy and 
 other extraneous particles, such sand may afford
 
 167 
 
 a tolerable substitute. But in cases where broken 
 granite has been employed for road-making, the 
 drift arising therefrom should in no wise be em- 
 ployed for the compounding of mortar. 
 
 Granite consists of distinct aggregations of 
 quartz, felspar, mica, and hornblende, each in a 
 crystalline form. Felspar is of a whitish, some- 
 times of a reddish, colour, quite opaque, and occa- 
 sionally crystallized in a rhomboidal form ; quartz 
 is less abundant, somewhat transparent, and of a 
 glassy appearance ; mica is dispersed throughout in 
 small glistening plates, the colour is dark and the 
 appearance metallic;* hornblende (a simple mi- 
 neral) is sometimes present, and is the same mineral 
 which imparts the deep green colour to the Plutonic 
 rocks, greenstone and basalt. The road-sand, derived 
 from the pulverization of granite, is, generally speak- 
 ing, a very unfit ingredient, and ought not to be 
 employed in the fabrication of mortars. The tritu- 
 ration of the micaceous particles forms a dust of no 
 coherence, and the harder particles become rounded 
 by attrition, thereby destroying a form so essential 
 to a proper adjustment when mixed with lime, viz., 
 sharpness and angularity. 
 
 There is also a description of granite much 
 used in the neighbourhood of London, for mend- 
 ing the roads, which forms a road-sand of very 
 inferior quality. This granite is of a very dark 
 colour, almost black ; it essentially consists of mica 
 
 * Jamieson, " Mechanics of Fluids," note G, page 459.
 
 168 
 
 and white felspar, the former in great abundance. 
 When pulverized, it becomes a gray powder, te- 
 nacious and clay-like while wet, but drying to a 
 fine micaceous dust, containing a portion of iron. 
 
 In the neighbourhood of Great Malvern, the 
 roads are repaired with the sienitic granite of the 
 locality. The sand, produced from the decompo- 
 sition of a portion of the rock, is red,* opaque, and 
 angular, in large grains. When washed it yields a 
 small portion of reddish-coloured residuum, which 
 contains iron. Acid has no effect upon the stone. 
 
 The sand mostly used in London and its 
 vicinity for the manufacture of good mortar, is pro- 
 cured from the bed of the river Thames, above the 
 bridges. This sand has acquired a standard reputa- 
 tion among the principal architects and builders of 
 London, and we shall presently show that its good 
 qualities have not been over estimated by the 
 profession. The river Thames passes through a 
 country where the contiguous stratum is calcareo- 
 silicious and argillaceous. The immense number 
 of weirs, culverts, road-drains, &c., which are dis- 
 charged into the river, deposit an immense mass of 
 heterogeneous matter, consisting of calcareous,ybssi/, 
 guartzose,^ and flint-sands, particles of coal al- 
 luvium, and much iron.^ Sea-sand, flints, and 
 marine debris are also washed backwards and for- 
 
 * A very considerable portion of the rock is composed of red felspar, 
 f From the pulverized particles of road gravel, which contains 
 much quartz. 
 
 J Iron mixed with the road-sand. In Mr. Babbage's interesting
 
 169 
 
 wards with the flux and reflux of the tide, dis- 
 tributing a sand of coarser quality than that 
 deposited by the inland tributaries. The Thames 
 sand, therefore, requires to be well screened and 
 washed, previous to its admixture with the lime, in 
 Avhich state it will be found to consist of two kinds 
 of materials the first a fine shingle, mixed with 
 calcareous particles, and the second a fine angular 
 silicious and quartzose sand. The accidental cir- 
 cumstances which occasion the deposit of a fine and 
 coarse sand in the bed of the river Thames are 
 the chief causes of its superiority as an ingredient 
 in the composition of mortar, for the interstices 
 between the larger and more quartzose particles be- 
 come partly occupied by the angular and sharp frag- 
 ments of the finer sand, which firmly unite with 
 the cement, wedging and dovetailing them together. 
 
 It is almost unnecessary to observe, that washed 
 sea-sand will produce precisely the same effects. 
 
 Thames ballast (used for concrete) is an ad- 
 mixture of sand and small stones, charged with the 
 impurities mentioned above ; it is procured from 
 below Blackfriars Bridge. A sample of this mix- 
 ture, tested with acid, effervesces considerably, and 
 deposits much clay containing iron. A washed 
 fossil or pit-sand, of very fine quality (gray colour), 
 
 work on the " Economy of Machinery," it is stated, that "every coach 
 which travels from London to Birmingham distributes about eleven 
 pounds of wrought iron along the line of road between those two places." 
 The result of this calculation was derived from observations made by 
 Mr. Macneill, the superintendent (under the late Mr. Telford) of the 
 Holyhead roads.
 
 170 
 
 used by plasterers, also effervesces with acid. Silver 
 sand, for fine stuff, is procured from the Isle of 
 Wight. This sand is angular, transparent, and 
 colourless ; acid has no effect upon it, and it is per- 
 fectly free from impurities. 
 
 The fossil and land-sands of Bagshot Heath, 
 Highgate, and Hampstead (when washed and 
 cleansed from the impurities which they contain), 
 are employed for internal work, such as plas- 
 tering, &c. These sands are exceedingly nume- 
 rous and diversified ; the quantity of extraneous 
 matter contained in some samples is shown by 
 the following 
 
 Analysis of Three Samples of Bagshot Sand.* 
 
 No. 1. 
 
 SiliciousSand . . lli ..; . 82 
 
 Alumine 2 . 
 
 Oxide of Iron 7 
 
 Lime . . . '"''-.' ..... 
 
 Vegetable Matter ...... 9 
 
 100 
 
 No. 2. (Partaking of a Clay appearance?) 
 Silex and Silicious Sand ... 85 
 Alumine . . -. ." .... 6 
 
 Oxide of Iron 5 
 
 Lime !} : '.''.. .*-' '.'' ' . ... 1 
 Vegetable Matter 3 
 
 100 
 
 * From some specimens in the " Polytechnic Institution," Ilegent Street. 
 
 - 

 
 171 
 
 No. 3. 
 
 Silicious Sand 90 
 
 Alumine 1 
 
 Oxide of Iron 4 
 
 Lime 2 
 
 Vegetable Matter i '..,.;. . 3 
 
 100 
 
 A section afforded by the excavations made 
 during the progress of the works at the North 
 London Cemetery,, High gate, induced us to examine 
 some other specimens of these sands in detail. Im- 
 mediately under the alluvium is a coarse, gravelly, 
 or craggy bed, in which is contained a broken 
 stratum of indurated sand, highly impregnated with 
 metallic oxide. The stratum next in succession con- 
 sists of a series of red sandy beds, much intermixed 
 with loam, followed by a thick stratum of very 
 fine light-coloured sand, nearly free from impu- 
 rities. A cursory analysis of these sands enables us 
 to give the following particulars concerning their 
 quality, &c. 
 
 The ferruginous mass of sand or sand-rust (as 
 it is provincially termed), is stratified and highly 
 indurated ; upon examination with a strong lens, 
 the particles appear to consist of crystallized quartz, 
 which in themselves are chiefly transparent and 
 colourless, but are much stained by contact with the 
 ferrugino-silicious cement which connects the mass. 
 The external appearance of the sand is highly
 
 172 
 
 metallic, and of a dark brown colour ; when pul- 
 verized and washed, it leaves scarcely any deposit, 
 and is not affected by the action of acid. After 
 maceration in dilute sulphuric acid, and the liquor 
 being filtered, the iron is separated from the sand 
 in the form of a dense blue precipitate, by adding 
 prussiate of potass ; or, a cloudy precipitate (iron) of 
 a reddish brown colour, in considerable quantity, 
 may be obtained, by adding a solution of pure am- 
 monia to the impregnated acid. The red sand from 
 the loamy beds, when washed and separated from 
 the clay, consists of very fine seed-like transparent 
 grains, of a reddish brown colour. The clay, or 
 loam, is of a bright yellow colour, and very tena- 
 cious ; it contains less iron than the previous speci- 
 men. The last specimen is a light-coloured glassy 
 sand, nearly pure, and consists of finely commi- 
 nuted angular fragments of silicious matter ; it does 
 not appear to contain iron, but is nevertheless ad- 
 mirably adapted for the manufacture of mortar. 
 
 A specimen of concreted sand procured from 
 Sandy, in Bedfordshire, when microscopically exa- 
 mined, exhibited appearances analogous to the spe- 
 cimen of iron-sand before described. Considerable 
 difficulty was experienced in cleansing this and the 
 former specimen, from the metalliferous cement 
 which connected the quartzose particles together. 
 Frequent washing had no other effect than that of 
 detaching the more earthy particles from the mass ;
 
 CO LOUR OF CLAY S 
 
 WHEN SEPARATED FROM THE STONE. 
 
 
 LEEDS FLAGGING. 
 
 BLACK GRANITE. 
 
 1 
 
 IDLE FLAGGING 
 
 KEXBORO' SAND STONE 
 
 ENSHURST SAND STONE 
 
 MALVERN SIFNIT 
 
 \ 
 
 FOREST OF DEAN SANDSTONE 
 
 L 
 
 DRECTOF DEAN SANDSTONE
 
 173 
 
 but, upon macerating the sand in dilute sulphuric 
 acid * for four or five days, the iron became sepa- 
 rated, and the sand, after being washed, was left in 
 nearly a pure state. The sand consists of large 
 quartzose particles, colourless, transparent, and of 
 very irregular figure, but much worn and rounded 
 by attrition. The test of ammonia applied to the 
 filtered acid, gave a more dense and copious deposit 
 than any other specimen submitted to examination. 
 The geological deposit to which this description of 
 sand belongs, t contains a sandstone of great hard- 
 ness and durability. It is much used in Kent, 
 Sussex, and some parts of Norfolk, as a paving and 
 building stone. The groin work of Battle Abbey, 
 in Sussex, is mentioned by Mr. Conybeare, as 
 being constructed with a free-stone belonging to this 
 series. 
 
 The sands derived immediately from the dis- 
 aggregation of sandstone rocks^ next demand our 
 attention. 
 
 The following series of sandstones are princi- 
 pally aggregations of quartzose particles, cemented 
 together with a portion of clay ; the clay consist- 
 ing of silex, alumina, and iron, in combination 
 
 * A more detailed account of the action of acids on clays, sands, 
 &c. will be given in another part of this work. It will be perceived 
 that our present observations chiefly apply to the quality of a few 
 varieties of the quartzose sands and sandstones. 
 
 t Iron sand. 
 
 I The nature and quality of sandstones, and the uses to which they 
 may be applied in engineering operations, will form the subject of a 
 distinct chapter.
 
 174 
 
 In one instance, only, was effervescence perceived, 
 viz. in the specimen of stone, No. 1, from the Forest 
 of Dean. 
 
 The stones were examined in the following 
 manner : 
 
 A specimen of each was pulverized, and a por- 
 tion of the sand was carefully washed, in order to se- 
 parate the aluminous powder, &c. Dilute sulphuric 
 acid was now added, and the sand was again washed 
 and examined with a good microscope, to detect its 
 quality. The clay, being subjected to the action of the 
 acid, in order to separate the iron, was left to mace- 
 rate, for some time ; the acid from the clay was then 
 filtered through white filtering paper, digested, and 
 finally tested with a solution of pure ammonia, which 
 precipitated the iron, &c. The clays were then dried 
 and reserved for further examination. 
 
 Bramley Fall Sandstone, No. 1 (Yorkshire). 
 
 A brown-coloured sandstone of coarse grain. 
 This stone is difficult to work to a good face, but is 
 nevertheless a good weather stone. It is now much 
 used in situations where granite was formerly em- 
 ployed,* and is in some respects superior to it, 
 which will be hereafter explained. This stone pul- 
 verizes to a coarse brown sand. When separated 
 
 * Such as bases to columns and plinths, springing stones to arches, 
 :c. &c.
 
 175 
 
 from the clay, &c. by washing, it exhibits a sand 
 composed of large rounded grains of quartz. Some 
 of the grains are colourless and transparent, many 
 are tinged with brown, and others are white and 
 opaque. Acid has no effect upon the sand from this 
 stone, but the clay (remarkably small in quantity, 
 and of a fine buff colour) yields a portion of iron 
 when tested as above described. 
 
 Bramley Fall, No. 2. 
 
 A light-coloured specimen, finer grain than the 
 above. The sand, when washed, appeared angular, 
 transparent, and colourless. Clay, buff-colour, small 
 in quantity, and yielded a slight trace of iron. Acid 
 produces no effect upon the stone. 
 
 Holton Sandstone (Yorkshire). 
 
 A light brown sandstone of fine grain. Stra- 
 tification widely separated. The sand, when sepa- 
 rated from the clay by washing, appeared in the 
 form of fine, round, seed-like transparent grains, 
 of a light brown colour, interspersed with micaceous 
 particles. Acid has no effect upon this stone, but 
 the clay (light drab colour) yields iron in tolerable 
 quantity.
 
 176 
 
 Kirby Sandstone (Yorkshire). 
 
 A drab-coloured sandstone of coarse grain. 
 Stratification widely separated. When pulverized, 
 the sand is of a light brown colour. Washed and 
 separated from the clay, the particles of sand are 
 found to consist of angular quartzose grains, trans- 
 parent and opaque, intermixed with scales of mica. 
 The colour of the clay is light brown, and yields iron. 
 Acid has no effect upon the stone. 
 
 Leeds Flagging (Yorkshire). 
 
 Light drab-coloured sandstone of fine grain, 
 closely stratified, but splits readily at the matrices 
 or divisions, which are very smooth, and coated 
 with mica. When pulverized, gives a fine light 
 brown sand. Washed and separated from the clay, 
 the particles of sand exhibit the appearance of very 
 fine quartz -like grains, having a brown tinge, and 
 particles of mica intermixed with the sand, colour of 
 clay, dark yellow. The test (ammonia) gave little or 
 no indication of iron. Acid has no effect upon the 
 stone. 
 
 Mexborough Sandstone (Yorkshire.) 
 
 A drab-coloured sandstone of coarse grain. 
 Stratification widely separated. When pulverized,
 
 177 
 
 gives a fine light brown sand. Washed and se- 
 parated from the clay, the grains appear like small 
 fragments of gum, some of which are transparent. 
 Colour of clay, yellow, and contains iron. Acid has 
 no effect upon the stone. 
 
 Green Moorstone (light coloured) (Yorkshire). 
 
 A dark drab-coloured stone, of very compact 
 texture. Stratification indistinct. Exhales an earthy 
 odour when breathed upon, and sulphurous smell 
 freely rubbed with an iron point. When pul- 
 verized, gives a fine light drab-coloured sand, which 
 forms a stiff tenacious paste, when mixed with a 
 small quantity of water. The sand, when washed 
 and separated from the clay, exhibits minute seed- 
 like transparent grains, of a brown colour. When 
 the acid from the clay is tested with a solution 
 of ammonia, much iron is precipitated. The clay 
 is of a drab colour. Acid has no effect upon the 
 stone. 
 
 Moorstone (light coloured), No. 2 (Yorkshire). 
 
 A very compact stone, fine grain, gray colour, 
 and indistinct stratification. When pulverized, gives 
 a fine light gray sand. The grains of sand, when 
 washed and separated from the clay, are of a dull
 
 178 
 
 white colour, transparent, minute, and rounded. 
 Colour of the clay, dark drab ; contains much iron. 
 Acid has no effect upon the stone. 
 
 Idle Flagging (Yorkshire). 
 
 A dark cream-coloured sandstone, closely 
 stratified, and possessing a fine grain. When pul- 
 verized, gives a very light brown sand, or powder. 
 Washed and separated from the clay, the grains 
 appear in small, sharp, transparent, silicious par- 
 ticles, slightly tinged with brown. Colour of the 
 clay, light brown, contains iron, which is preci- 
 pitated slowly. Acid has no effect upon the stone. 
 
 Penshurst Sandstone (Kent). 
 
 A tender sandstone, fine grain, deeply tinged 
 with iron oxide throughout its substance. When 
 washed and separated from the clay, the sand 
 appears in fine, seed-like, red grains. Acid has no 
 action on the stone. The colour of the clay is 
 a dark brown, approaching to red, and contains 
 much iron. 
 
 Sheffield Stone (Yorkshire). 
 
 A light gray sandstone, fine grain, and com- 
 pact texture. When pulverized, gives a light gray
 
 179 
 
 sand. Washed and separated from the clay, the 
 grains of sand appear rounded, seed-like, and 
 nearly colourless. Colour of clay nearly white; 
 contains much silex and little iron. Acid has no 
 effect upon the stone. 
 
 Sandstone, from the Forest of Dean. No. 1. 
 
 A remarkably hard light gray stone, with a 
 slight tinge of red. The grain is coarse, but the 
 stone is capable of being worked to a smooth face. 
 When pulverized, it gives a coarse pink-coloured 
 sand. Washed and separated from the clay, the 
 sand appears slightly granitic, of various colours, 
 viz., red, brown, opaque, colourless, and transparent. 
 The colour of the clay is a dull red, and contains 
 much iron. This stone effervesces slowly in acid. 
 
 Sandstone, from the Forest of Dean. No. 2. 
 
 A very hard light gray-coloured sandstone, 
 finer grain than the above, and works to a good 
 face. When pulverized, gives a light drab-coloured 
 sand. Washed and separated from the clay, the 
 sand appears in small quartzose grains, colourless 
 and transparent. Colour of the clay, drab. Acid 
 has no effect upon the stone. 
 
 * Lighter colour than Kirby-stone.
 
 180 
 
 Each of the above specimens of sandstone 
 is described as containing clay;* this ingredient, 
 however, varies considerably in quality. In some 
 of the specimens, the alumina is so small in quan- 
 tity as to be with difficulty separated from the 
 mass. 
 
 The relative value of the various sands, as 
 ingredients in the composition of mortars, stands 
 next in order for our attention. 
 
 * We had some doubt of the propriety of naming these deposits 
 from the sand of sandstones " clays," as it was found that when per- 
 fectly dry, most of them might be readily pulverized. Upon microscopic 
 examination, they also exhibited very fine silicious particles ; but upon 
 discovering that they could be instantly formed into an unctuous paste, 
 when remixed with water, we have on that account ventured to retain 
 the term. 
 
 END OF THE FIRST PART. 
 
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 I Details of Kilsby Tunnel (Election, Plans, and 
 
 LEIDS 
 
 Esq., P.I.C.E., Directing Engineer. 
 Details of Tunnel. 
 
 SELBY RAILWAY Janies Walker, \ Sections). 
 
 Weedon Viaduct, (Elevation, Plans, and Sec- 
 tions). 
 
 With detailed Specifications, Estimates, and 
 Practical Observations, &c., &c. 
 
 Details of Leeds Depot 
 Details of Selby Depot. 
 Details of Cranes. 
 Details of Turntables. 
 
 LONDON AND BIRMINGHAM 
 
 ILWAY Robert 
 
 Stephenson, Esq., M. Inst. C.E., Directing 
 
 Engineer. 
 Permanent Rails as laid down upon part of 
 
 Railway. 
 Details of Iron Bridge under Wriolhesley-street 
 
 (Elevation and Plan). 
 Details of Iron Bridge under Hampstead Road 
 
 (Elevations of Main and Middle Ribs, Plans, 
 
 and Section of Ribs). 
 Details of Retaining Wall from Park-street to 
 
 Regent's Canal (Plan, Elevation, and Sections) 
 Method of Working the Primrose-Hill Tunnel. 
 
 I LONDON AND GREENWICH RAILWAY : -George 
 
 Landmann, Esq., M.I.C.E., Engineer. 
 Bridge over the Spa Road (Elevation and Plan, 
 
 MIDLAND COUNTIES RAILWAY: Charles Vig- 
 
 notes, Esq., M.I.C.E., Directing Engineer. 
 Viaduct over the River Avon. 
 Viaduct over the River Trent. 
 
 NORTH UNION RAILWAY: C. Vignoles, Esq. 
 Viaduct over the River Ribble. 
 
 SLAMANNA-N RAILWAY: John Macneil, Eq. 
 M.I.C.E. 
 
 Extract from the 3rd Volume of the Railway Magazine, p. 449. 
 
 " The author might well call his book ' Rail- 
 way Practice," for nothing appears to be his 
 seful wor 
 
 object but to make a plain 
 
 ork for the 
 
 practical engineer; ample in the various details 
 and descriptions, yet unencumbered with super- 
 fluous matter. To the illustrations of existing 
 works the author has added twelve plates of 
 original designs, for bridges, tunnels, viaducts, 
 &c., in various styles of architecture, in which 
 he has shown considerable taste and compass of 
 
 invention. We quite agree with him that orna- 
 ment in railway works has been too much 
 neglected. We certainly should be the last to 
 advocate extravagance in any shape, but we do 
 think with the author, that where ' such enor- 
 mous sums are being expended upon railway 
 works, the opportunity should not be lost of 
 erecting edifices which should command the 
 attention of the refined and contemplative, as 
 well as of the scientific, of future ages.' " 
 
 Extract from the 1st Volume of the Civil Engineers' Journal, pp. 36, 37 : 
 
 " The value of such books as the one now | practical work, valuable not only to the student, 
 before us cannot be too highly appreciated." but to every member of the profession." 
 " It must be strictly understood as a sound | 
 
 Will be Ready in a few Days, The 
 APPENDIX TO RAILWAY PRACTICE, 
 
 Consisting of a copious Abstract and Glossary of the Evidence on the 
 several Railway Bills when before Parliament, properly digested, 
 abbreviated, and arranged with the marginal notes. 
 In 1 Handsome 4to. Volume, nearly 4O Sheets of letter Press, 
 
 Illustrated with the Six large Working Drawings, beautifully engraved 
 on Copper by KELSALL, of Hawthorne's Paris and Versailles
 
 Locomotive Engine, and Descriptions, which was considered by the 
 British Association at their last Meeting at Newcastle to be the 
 most improved Engine yet invented. 
 
 Those who are not conversant with the getting up of such a Work as the 
 present, would be perfectly astonished at the immense labour, independently 
 of the correct judgment, and accurate discrimination required in the same. 
 It may justly be called an Herculean task ; and it is confidently submitted to 
 the Profession as a mine of useful practical knowledge, that no Engineer, 
 whether the most eminent, or just commencing as a student, can possibly do 
 without ; it must be a constant companion in the field of operation or the 
 quiet study of his profession. 
 
 Among the several witnesses examined will be found the following eminent 
 Engineers. 
 
 Henry H. Price, Esq. 
 Thomas Cabrey, Esq. 
 Dr. Dionisius Lardner. 
 
 George Stephenson, Esq. 
 Robert Stephenson, Esq. 
 I. K. Brunei, Esq. 
 J. U. Rastrick, Esq. 
 
 Joseph Locke, Esq. 
 
 harles Vigno 
 Henry R. Palmer, Esq. 
 
 Charles Vignoles, Esq. 
 Henry R. Palmer, Esq. 
 George W. Buck, Esq. 
 
 George Leather, Esq. 
 William C. Mylr.c, Esq. 
 Francis Giles, Esq. 
 Col. G. Henderson, 
 &c., &c., &c. 
 
 The fallowing brief account of the useful contents of this work mil show the absolute 
 necessity of every Engineer possessing it : 
 
 Descriptions of the severalRailways throughout 
 the kingdom, with the nature of the works, gra- 
 dients, costs, cuttings, embankments, tunnels, 
 method of working, and engines used upon same. 
 
 Numerous and voluminous remarks and ob- 
 servations upon the economical laying out of 
 Railways, with investigations of the several dif- 
 ferent views of the subject. 
 
 Re 
 inclin; 
 
 rks upon Slopes in various soils, and the 
 ion? at which they will stand. 
 Description of the several kinds of Bridges, 
 
 and costs of same ; numbe 
 lines of Railway, &c 
 
 of same on diffe 
 
 Remarks upon the inclinations of Roads over 
 
 bridges, &c. 
 Account of the 
 
 everal Rails, Cha 
 
 used 
 
 upon the different lines of railway, with their 
 weight, cost, &c. 
 
 Remarks upon Oak, Larch, and Scotch Fir 
 Sleepers, and their durability ; also, the effect of 
 Kyan's Patent Liquid upon same, &c. 
 
 Comparison between Blocks and Sleepers.with 
 their cost, durability, and wear and tear, &c., 
 upon same. 
 
 Remarks upon the expediency, working, ex- 
 pense, ventilation, &c., of Tunnels, under all 
 circumstance?. 
 
 Observations upon the Ventilation of Tnnnels, 
 with the effect of Shafts. 
 
 A full investigation of the theory of Gradients, 
 with numerous formulas for comparing the slopes 
 upon competing lines of Railway, and the rela- 
 tive power required on different planes, with 
 mparisons and parallels, and the 
 
 litable for 
 and tear, 
 
 their several com 
 
 effect of friction, _ 
 
 of circumstances, with the Engi 
 
 different planes, and their cost, 
 
 and fuel consumed, &c. 
 
 Comparison between Fixed and Locomotive 
 F-ngines, in the working of Inclined planes, and 
 the" relative expense of same, and numerous 
 experiments npon inclined planes. 
 
 Numerou 
 
 stigatio 
 
 alculations, and 
 
 Risk of Slips and Contingencies. 
 NiimerousEstiinates of Railways under varic 
 
 circumstances. 
 
 Observati 
 
 Observati 
 of Railway Wagons, with thi-ir cost, weilu, 
 
 upon Railway Carriages, &c. 
 the different descripti:i 
 
 and capacity of Fame. 
 
 Remarks upon Land in diffc 
 
 (nations 
 
 Remarks upon Floods and the precautions 
 taken to prevent Railways injuring the countiy 
 by penning back (he floods, &c., with the de- 
 scription of the means taken upon the River 
 Thames of protecting the navigation; account 
 of the locks, weirs, &c. 
 
 Remarks upon the effect of Railways 
 
 the sever 
 
 in their viciniti 
 
 upon 
 
 Comparison and cost of various Depots. 
 
 Comparative Expense of different Railways, 
 with tlicir cost permile, and the several amounts 
 of their earth work. 
 
 Observations upon different modes of Teaming, 
 with the expense of same, and account of the 
 greatest quantities there can be teamed per day. 
 
 Observations and Comparisons between the 
 several methods of letting Railway Works. 
 
 Remarks upon Night work, &c., and working 
 in the winter effect of frost, &c. 
 
 Observations upon the use of Locomotives in 
 executing the work, cost of same, &c. 
 
 Remarks and Experiments upon Railway- 
 Curves of various nidius. 
 
 Numerous remarks upon Contractors, and in- 
 stances of their tricks, profits, losses, &c. 
 
 Observations upon Labourers, navigators, &c. 
 
 Remarks upon Ballasting, &c. 
 
 With numerous Descriptions and accounts of 
 the Manufactures, Traffic, Resources, Population, 
 Importance, and Position of the various Towns 
 i-pon the different lines of Railway. 
 
 The whole interspersed with innumerable Re- 
 marks and Data connected with the subject, 
 highly valuable to young practitioners, and inte- 
 resting to the profession generally. 
 
 results, of the power of Breaks. 
 
 The Subscribers to the Railway Practice are respectfully informed that, on 
 transmitting the following notice, either direct to Mr. Williams, 106, Great 
 Russell-street, or through their respective Booksellers, they can have this 
 Appendix for 21s., instead of 2 2s., which is less than cost price. 
 
 " I beg to claim the Glossary of Railway Practice for 21s., having subscribed 
 to the Railway Practice." Sign the name.
 
 Preparing for publication, by Subscription, 
 
 DRAWINGS OF STEAM ENGINES, 
 
 AND OTHER MACHINERY, 
 
 In order to guide the Engineer, Student, and Mechanic, in manufac- 
 turing Working Models for practical purposes, or for the Lecture 
 Table, illustrated with numerous Plates, clearly and accurately 
 detailed by Drawings, full size of original Models, of first rate work- 
 manship. 
 
 This novel Work, for novel it is, as nothing of the kind has yet been pub- 
 lished, cannot fail of success, as its utility is so obvious that the Publisher, 
 calculating upon an unusually extensive sale, has determined to bring it out 
 at the very lowest price it is possible to be published at, 80s. to Subscribers, 
 forming a handsome quarto volume. Gentlemen will please to forward their 
 names to the Library of Arts, or to any respectable Bookseller in Town or 
 Country. 
 
 Now ready for delivery, Part I., DAVY on ARTIFICIAL FOUNDATIONS; 
 
 OR, THE 
 
 AMATEUR, ARCHITECT, ENGINEER, AND OPERATIVE 
 
 BUILDER'S 
 CONSTRUCTIVE MANUAL, 
 
 Being a Practical and Scientific Treatise on the Construction of Arti- 
 ficial Foundations for Buildings, Railways, &c. With a comparative 
 view of the application of PILING and CONCRETING to such purpose ; 
 also, an investigation of the nature and properties of the Materials 
 employed in securing the stability of Buildings. To which is added, 
 an Analysis of the principal Legal Enactments affecting the opera- 
 tions of the PRACTICAL BUILDER ; illustrated by notes of cases 
 occurring in actual practice. 
 
 Elegantly printed in 1 Volume, 8vc., illustrated with 13 useful Plates, 
 in Clotli, geld letters, Price 12s. 
 
 BY CHRISTOPHER DAVY, ARCH. & C.E. 
 
 The following classification of afeiv of the more important features of this work will 
 at once exhibit its comprehensiveness as a Manual to the Architectural Student 
 and Engineer, and, as a work of useful and practical reference, of the highest 
 importance to the successful operations of the Practical Builder. 
 1st. On the consideration of the quality of 
 
 the different Strata of E.rths, and of tlie sub- 
 soil. 2nd. The construction, calculations, and 
 
 use of the different varieties of the Pile Driving 
 
 Engine, and their effects in the operation of 
 
 Piling. 3rd. On the varieties of Piling, and 
 
 its application to specific Bui/ding purposes. 
 
 arising from the obscurity with which certain 
 cl:iuses are worded. 
 
 The information collected on each and all of 
 these subjects is of great interest and of Ihe 
 first authenticity. A sort of chamber counsel, 
 to be consulted by all who would wish to build 
 lasting fabrics on secure foundations, and steer 
 clear of the law and its manifold meshes. Bat 
 to the matter of the w^>rk ; what, after all, is 
 the matter to be most looked to ; the Part (1.) 
 before us contains 1st. A chapter of excellent 
 observations on strata and subsoil, with descrip- 
 tions of the best sort of boring apparatus and 
 modes of using them. 2nd. Another chiefly on 
 timber and metallic piling. 3rd. A full ac- 
 ci -tint of the composition and application of 
 
 Jliiilding Stone, and their employment in foiiri- j Beton (translated from the French of M. Keli- 
 dation?. The various subjects comprised in this dor.) 4th. An analysis of British limestones. 
 work will be further illustrated by useful Tables 5th. Modes of calcining limestones, including 
 and Memoranda, collected together from nume- j Dr. Hijgius's experiments and descriptions of 
 rons sources of acknowledged worth, and illus- , the most approved English, Scotch, and Irish 
 tratcd with numerous Cuts. The Building Act, I kilns. And, 6th. Professor Fuch's experiments 
 divested of its legal technicalities, will also be j on mortar Constituents of ordinary mortar 
 explained, accompanied by notes and illustra- Examples from public works Varieties of sand 
 
 applicat 
 
 4th. On the present use of Concrete, its nature, 
 varieties and application ; its employment in 
 important government establishments ; valuable 
 experiments relative thereto. 5ih. Compara- 
 tive view of Piling and Concreting for founda- 
 tions. 6lh. On the manufacture, quality, and 
 employment of Vrick, for foundations, SjC. 
 7th. On the varieties and composition of Mor- 
 tars and Limes. 8lh. On the varieties of 
 
 tions of such points as nre of doubtful import, Examples from the disaggregatiou of British 
 or as may appear to require further elucidation*, I iandtones Action of acids on sands, &c. &c.
 
 The Publisher feels much pleasure in announcing the above as an entirely 
 original work, of the greatest utility to the Amateur, Engineer, Architect, and 
 Practical Builder ; Mr. Davy being expressly authorised, by the Master- 
 general of the Ordnance, to give in this work all the experiments and highly 
 important results made under the direction of the Board of Ordnance at 
 Woolwich. 
 
 The above valuable Compendium also contains a Register of the principal 
 Geological Formations in each of the Counties of England and Wales, with 
 the situation of the principal Stone Quarries, Lime Works, &c., expressly 
 compiled for the use of Architects, Railway Contractors, and others, forming 
 an invaluable index to the various depositaries from whence building materials 
 may be procured. 
 
 Vol. 2 is preparing for tne Press. 
 
 Now Ready, 
 
 THE PUBLIC BUILDINGS 
 
 Erected in the West of England, from the Designs, and under the 
 
 Superintendence of 
 
 JOHN FOULSTON, ARCH. 
 
 Price ft 4s, in 1 vol. royal 4to., cloth, gold lettered. 
 
 AT PLYMOUTH : the Royal Hotel, Assembly Rooms, and Theatre .; the 
 Athenceum, Public Library, Exchange, St. Andrew's Chapel, and the Interior of 
 St. Andrew's Church, as altered. At DEVONPORT : the Town Hall, Public 
 Library , Mount Zion Chapel, and the Column erected to commemorate the event 
 of changing the name from Plymouth Dock to Devonport. 
 
 This Work comprise Buildings erected in the Greek, Egyptian, Hindoo, Old 
 English, Ornamental, and Rustic Cottage Styles, &c. 
 
 Correct Plans, Elevations, and Sections are given of each, in which the 
 best examples have been selected, and the most scrupulous attention paid to 
 the Proportions, Mouldings, and Ornaments of the Architectural parts, 
 according to their respective styles, and to the public, domestic, or other 
 purposes for which they were erected, that they may be adhered to, and 
 adopted with perfect confidence. Correct copies are given of the Working 
 Drawings for each building, and descriptions of the various parts worthy of 
 attention. 
 
 IN CORNWALL: the Plans, Elevations, and Sections, of the County 
 Lunatic Asylum, erected near Bodmin, the boundary wall of which incloses 
 nine acres. This Building is also erected secure from fire. The particular 
 construction of the Iron Roofs, Floors, Doors, Windows, &c. are detailed from 
 the Working Drawings. 
 
 Extracts from the descriptions of these Buildings, published by different persons, who 
 have expressed their feelings and opinions in their own way : 
 
 Royal Hotel, Assembly Rooms, and Theatre. ample of domestic Architecture, built by Richard 
 "The design and execution of this noble pile Bromley, Esq. The usual nursery toy of cockney 
 sufficiently attest the professional eminence of origin di nominated a 'Villa,' is brought into 
 the Architect, to whose truly classical taste the wholesome ridicule by the two residences just 
 town is indebted for this, atifl the numerous alluded to, which really are ' Villas ' in a sense 
 other specimens of his art, which adorn our that Mecienas himself would have admitted, 
 streets, and excite just and universal admira- The eastern part of this extensive suburb is also 
 tion." Panorama of Plymouth, by the Rev. distinguished by the architectural pretensions of 
 S. Ro'jae. 1821, p. 40. j numerous other residences, lately built, or now 
 
 "On the right is an edifice in the Egyptian erecting." 
 
 style of architecture, which is now used as the Plymouth." Princess Sqvare, is essentially 
 Devonport Public Library. Here again the Architectural in character, and deserves the 
 talents of Mr. Foiilston have been successfully notice of the visitor; this is also from the de- 
 exerted. ' Much judgment,' observes the Rev. i signs of John Foiilston, Esq., the first modern 
 S. Rowe, 'has been displayed by the Architect [ Architect of eminence, who essayed to give a 
 in combining the massive parts appropriate to this j classic tone to Plymouth: how successful has 
 style with the greatest effect ; and when the de- I been that essay, his followers will honestly 
 sign wasshown(byMr.Cole,Sir John StAubyn's I avouch, while they gratefully regard him as a 
 stewar<!)to Monsieur Denon, he expressed great powerful pioneer, who has smoothed down the 
 pleasure, and signified, 'that it was the best ! ruggedness of the public mind, and left it readily 
 attempt to appropriate Egyptian Architecture to | and generously accessible to their professional 
 domestic purposes that had ever come under his taste and exertions." J\'ettleton's Guide, by 
 
 notice.' " 
 
 T^avers't House is also another select ex- 
 
 Georye Wightwick, Architect, 183fl.
 
 EZ.EW1ENTS OF LEVELLING AND 
 SURVEYING. 
 
 BY EDWARD JONES, C. E. 
 
 Repeated applications having been made to Mr. Williams for a work of the 
 above class, he has engaged with Mr. Jones, as a gentleman of great 
 practical experience in this Branch of Engineering, to get up a work which 
 shall prove a Vade Mecum for the Architectural and Engineering 
 Students. 
 
 Now ready, in One Volume, 8vo., enriched with many useful Plates, 
 
 AW ELEMENTARY TREATISE ON 
 
 CIVII. ENGINEERING. 
 
 BY PROFESSOR MAHAN, 
 
 Of the United States College for Engineers. 
 
 The great success of this work in America, having run through a very large 
 Edition, has induced the Proprietors to bring out a second Edition in 
 England. It is singular that no work forming a Manual of Engineering 
 has yet been published in this country. Mahan's work is the very thing 
 wanted, for Professor Barlow has given it the high sanction of his 
 approbation. 
 
 Price 14s in Clotb. 
 
 A NEW WORK ON 
 PRACTICAL ARCHITECTURE, 
 
 BY ALFRED BARTHOLOMEW, ARCH. 
 
 Consisting of about 500 pages of closely printed Letter-press, an 
 entirely new work, to be entitled, " SPECIFICATIONS FOR 
 PRACTICAL ARCHITECTURE, accompanied by an Essay on 
 the Decline of Excellence in the Structure of Modern English 
 Buildings," illustrated by more than 100 Wood Engravings, pointing 
 out practical defects, and their remedy ; and exhibiting improve- 
 ments in construction. 
 
 ELEMENTS OF 
 ARCHITECTURAL CRITICISM, 
 
 FOR THE USE OF 
 
 STUDENTS, AMATEURS, AND REVIEWERS, 
 BY JOSEPH GWILT, 
 
 Author of the Translation of Vitruvius, and other valuable works. 
 
 Illustrated with Plates of the MUSEUM at BERLIN, the GALLERY of 
 MUNICH, &c. ; to which is added in this second Edition, an AP- 
 PENDIX, in a short notice of the Foreign Quarterly Review. 
 1 vol. royal Svo. cloth, gold lettered, 9s. 6d. 
 
 Or the Appendix separately, price Is. 6d., or 2s. 6d. on large paper. 
 
 The First Edition not having the Appendix, any Gentleman can return 
 his copy and have the complete work, or the Appendix separate as may be 
 preferred. 
 
 A perusal of this work will show the necessity of every Student and Ama- 
 teur possessing so valuable a Guide in correcting his taste and informing his 
 judgment.
 
 ARCHITECTURAL ILLUSTRATIONS OF 
 
 CARLISLE CATH 
 
 DRAWN AND ENGRAVED 
 
 BY ROBERT WILLIAM BILLINGS, 
 
 Associate of the Institute of British Architects. 
 
 Printed uniform with BRITTON'S CATHEDRALS. The Subscription List 
 now open. 
 
 A REVIEW OF THE PROFESSIONAL LIFE AND WORKS 
 
 OF THE LATE 
 
 SIR JOKIf SOANE, 
 
 R.A. and Piofessor of Architecture at the Royal Academy, P.R.S., F.S.A., M.I.B.A., 
 
 and Member of various Foreign Academies. 
 
 Read at the ordinary Meeting of the Institute of British Architects, 
 held on Monday, 6th February, 1837, by THOMAS L. DONALDSON, 
 Honorary Secretary, Corresponding Member of the Institute of 
 France, and various other Foreign Academies. 
 
 Critical Reviews of all Sir John's Public Works, with a Chronological List 
 of the numerous Buildings,- Public and Private, executed during his profes- 
 sional career, with Two of his acknowledged best Designs one for a Royal 
 Palace made at Rome in 1799, the other for a Royal Palace made in 1821. 
 
 1 vol. cloth, price Is 6d, or 3s with the plates. 
 
 " A faithful Review, written in a concise and classical style." The Eiujineer and Architect's 
 Journal. 
 
 DESIGNS FOR MURAX. 
 
 MONUMENTAL TOMBS, and CHIMNEY PIECES, with useful Details to a 
 large scale ; the plates engraved on copper, from original Drawings 
 by F. FAULKNER, Architect, Author of the popular Works on Shop 
 Fronts, Designs for Churches and Chapels, Organ Builders' As- 
 sistant, &c. 
 The First and Second Series of 32 plates, neatly bound in cloth, gold lettered, 
 
 1 Is, or each Series separately, lOs 6d. 
 
 N.B. An Accurate Estimate accompanies the Work, prepared by one of the First Modellers in 
 London, who will guarantee to execute them at the sums named. 
 
 This is the latest work on the subject published; it has been submitted to several 
 Modellers, Sculptors, Sfc., who consider the ivork peculiarly serviceable from the 
 chasteness and beauty of the designs. Many of iliem have already been carried into 
 execution very successfully. 
 
 THE CATBEDRAX. OF GX.ASGOW. 
 
 Delineated in a SERIES of PLANS, SECTIONS, ELEVATIONS, 
 DETAILS, and VIEWS of the Cathedral of Glasgow, from accu- 
 rately measured drawings, by JAMES COLLIE, Architect. 
 1 vol. imperial folio, 2 2s. 
 
 Although GLASGOW CATHEDRAL possesses Architectural beauties of the 
 very highest order, and although her crypts are by far the most unique and 
 magnificent in the kingdom, and have been invested with such romantic in- 
 terest by the great master-spirit of the age, yet these beauties are unknown, 
 no successful attempt having been made towards their delineation a circum- 
 stance the more remarkable, seeing that the Cathedrals throughout England 
 have been so fully and splendidly illustrated. 
 
 Continuation of this Publishing Catalogue in tLe Press. 
 
 DRURY, Printer, Tooks Court, Chancery Lane.
 
 A 000022770 2