J STONES FOR BUILDING AND DECORATION BY GEORGE P. MERRILL, i i CURATOR OF GEOLOGY IN THB UNITED STATES NATIONAL MUSEUM. NEW YORK : JOHN WILEY & SONS, OS EAST TENTH STREET. 1891. r COPYRIGHT, iSgitj BY JOHN WILEY & SONS. ROBERT DBmraoid). *" BEOS., Electrotyper, Printers, 444 and 446 Pearl St., 326 Pearl Street, New York. New York. PREFACE. The work herewith presented is based upon the author's handbook and catalogue of the collection of building and orna- mental stones in the United States National Museum at Wash- ington. It differs from that work, however, in many important particulars, several new chapters having been added, others rewritten and the whole so far as possible brought down to date, A portion of the added matter is essentially the same, though in a somewhat different form, as originally appeared in the columns of Stone, the American Architect, the Scientific American Supplement, and other of our industrial journals. The writer's experience in preparing the extensive collection in the National Museum, at Washington, as well as its partial duplicate in the American Museum in New York City, has afforded him ample opportunity for becoming acquainted with the quarry products of the country at large, while extensive field trips, particularly in the eastern and extreme western United States, have given him -a practical insight into the resources of the regions as well as some knowledge concern- ing the usual methods of quarrying and working. That there is a demand for a comprehensive and not too technical a work on this subject has been emphatically im- pressed upon the writer many times during the past few years. How far the pages herewith presented shall supply this de- mand, it is left for the public to decide. The alphabetical arrangement of States adopted in Part II. will very likely at iii IV PREFACE. first be subject to criticism as unscientific. Such an arrange- ment for purposes of rapid reference, has however, been found so much superior to the usual geographic method, that excuses are not deemed necessary. The work, it should be stated, has been written from an American standpoint, and treats princi- pally of stones found within the limits of the United States, or imported from other sources. In but few instances are stones mentioned that are of purely historical interest. The full-page plates illustrating quarry views, were, with a single exception, drawn from photographs taken by the author. They may, therefore, be considered as reasonably accurate. Thanks are due the authorities of the Smithsonian Institution for the privilege of electrotyping such of the engravings in the original handbook as it was desired to reproduce here. GEORGE P. MERRILL SMITHSONIAN INSTITUTION, WASHINGTON, D. C., JUNE, 1891. TABLE OF CONTENTS. PART I. PAGE I. HISTORICAL i II. THE GEOGRAPHICAL DISTRIBUTION OF BUILDING-STONES IN THE UNITED STATES 10 III. THE MINERALS OF BUILDING-STONES 17 IV. PHYSICAL AND CHEMICAL PROPERTIES OF BUILDING-STONES 32 V. ROCK CLASSIFICATION 42 VI. GEOLOGICAL RECORD 43 PART II. THE ROCKS, QUARRIES AND QUARRY REGIONS. I. STEATITE: SOAPSTONE. 45 1. Composition and Uses 45 2. Soapstones of the Various States and Territories 47 II. SERPENTINE : VERDANTIQUE MARBLE 53 1. Composition, Origin and Uses of 53 2. Serpentines of the various States and Territories . 57 3. Foreign Serpentines ^ 72 III. GYPSUM : ALABASTER. 75 1. Composition and Uses of 75 2. Localities of Gy psu m in the United States 76 3. Foreign Alabasters 77 IV. LIMESTONES AND DOLOMITES 78 1. Chemical Composition and Origin 78 2. Varieties of ... 80 3. Limestones and Dolomites : Marbles 83 v VI TABLE OF CONTENTS. PAGE 4. The Onyx Marbles, or Travertines 116 5. Limestones and Dolomites other than Marbles 122 6. Foreign Limestones and Marbles 150 V. SOME MINOR ORNAMENTAL STONES 167 VI. TilE GRANITES AND GNEISSES 175 1. Composition and General Properties 175 2. Geological Age and Mode of Occurrence 177 3. Varieties of Granite 178 4. Uses of Granite 179 5. Granites and Gneisses of the various States and Territories.. 180 6. Foreign Granites 214 VII. THE PORPHYRIES: PORPHYRITIC FELSITES 217 1. Composition and Origin 217 2. Varieties of Porphyry 218 3. Uses of Porphyry 218 4. Porphyries of the Various States and Territories 219 5. Foreign Porphyries 221 VIII. THE LIPARITES 221 1. Adaptability of Tertiary and Post-Tertiary Rocks to Pur- poses of Construction 221 2. Mineral and Chemical Composition of the Liparites 222 3. Varieties of Liparite 222 4. Liparites of the Various States and Territories 223 IX. SYENITES, TRACHYTES AND PHONOLITES 223 1. Definition of Syenite 224 2. Localities of Syenite 224 3. Trachytes and Phonolites , 226 X. AUGITE (ENSTATITE, HYPERSTHENE) PLAGIOCLASE ROCKS (TRAP AND GREENSTONE IN PART) ; 228 1. Diabase 228 2. Gabbro and Norite 235 3. Melaphyr 238 4. Basalt 239 XI. AMPHIBOLE PLAGIOCLASE ROCKS (TRAP AND GREENSTONE IN PART) 1. Diorites and Kersantites 239 2. The Andesites 243 XII. SCHISTOSE, OR FOLIATED ROCKS 244 1 . The Gneisses 244 2. The Schists t TABLE OF CONTENTS. Vll PAGE XIII. FRAGMENTAL Rocks 245 1 . Sandstones, Breccias and Conglomerates 245 (a) Composition and Origin 245 (b) Varieties of Sandstone 248 (c) Sandstones of the various States and Territories 249 (d) Foreign Sandstones 287 2. Volcanic Fragmental Rocks 290 (a) Definition, Origin and Composition 290 (b) Varieties of 291 (c) Localities and Uses of 291 3. Argillaceous Fragmental Rocks (Clay Slates) 293 (a) Composition, Structure and Origin 293 (6) Uses of 298 ( li Permian. Permian. ^ So Upper Coal-measures. Is Carboniferous. Lower coal-measures. Millstone Grit. rt U Subcarboniferous. Upper. Lower. ' Catskill. " Catskill. 0) ( /^U ho rt Chemung. ) D_^ m "r g ' u ^ Genesee. c*i Hamilton. Hamilton. -SE Marcellus. c Corniferous. *0 s; > Corniferous. Schoharie. Q J Cauda-galli. "| 1 Oriskanv. Oriskanv. a! c | Lower Helderberg, Lower Helderberg. o > -g 1 Salina. Salina. > c S 3 f Niagara. c3 ^ ^ art Niagara. Clinton. .i S Medina. 8)S r ^ Cincinnati. OH C8 X5 w c Trenton. Utica. g 4j t rt j Trenton. *c Chazy. 5 "- 1 J^ j Canadian. Quebec. c/o Calciferous. Cambrian, ) Upper. ( Potsdam. or Pr i -> Middle. -j Georgian. mordial. ) Lower. ( St. John's. j Huronian. Arc'haean, Pre-Cambrian. ( Laurentian. PART II. THE ROCKS, QUARRIES AND QUARRY REGIONS. STEATITE : SOAPSTONE. This, although not properly a building stone, is of sufficient economic importance to merit attention. (l) COMPOSITION AND USES. The name soapstone is properly applied to a compact, dark bluish gray rock composed essentially of the mineral talc. It is therefore, like serpentine, a hydrous silicate of magnesia, consisting when pure of 65.49 percent of silica ; 31.75 per cent of magnesia, and 4.76 per cent of water. As a matter of fact few, if any known varieties, are chemically pure, but nearly all contain admixtures in the form of mica, chlorite, amphibole, quartz (popularly called flint), magnetite, pyrrhotite and pyrite. The stone is soft enough to be cut readily with a knife, or even with the thumb nail, and has a pronounced soapy feeling ; hence the name soapstone ; from the fact that it has in years past been used particularly by the aboriginal tribes for making rude pots, it has also received the name potstone. Steatite is the name commonly applied by mineralogists to these rocks, particularly the fine and compact light-colored varieties, while the eminently foliated or micaceous varieties are known as simply talc. 45 46 STONES FOR BUILDING AND DECORATION. The soapstones are suited for a considerable range of ap- plication. Although so soft they are among the most inde- structible and lasting of rocks, but are too slippery and perhaps of too sombre a color for general structural purposes. At present the chief use of the material in the United States is in the form of thin slabs for stationary wash-tubs. At one time it was extensively used throughout New England in the manu- facture of stoves for heating purposes, and to some extent for fire brick, the well seasoned stone being thoroughly fire-proof. The putting upon the market of unseasoned materials, or of material with bad veins which caused the stone to crack or fly to fragments when subjected to high temperature, aroused a prejudice against the employment of the material, and the manufacture is stated to have been to a considerable extent discontinued as a consequence. In the manufacture of either stoves or washtubs, slabs of considerable size, free from segre- gation nodules of quartz, pyrite or other minerals, or from dry seams, are essential. As but few of the now known outcrops can furnish material of this nature, the main part of the busi- ness of the country is in the hands of but two or three com- panies. The waste material from the quarries, or the entire output in certain cases, is pulverized and used as a lubricant or a white earth. Rubbed between the thumb and finger, the powder is smooth and oily, without a particle of grit, and its lubricating power is in some cases very remarkable. It is also used in soap making, for which purpose it can, however, be considered only as an adulterant, increasing the weight but not the cleansing properties of the article. It is further used as a " filler " in the manufacture of paper, and as a dressing for fine leathers. Small quantities are used in the powdered form by shoe and glove dealers also. The pure creamy white talc, such as is obtained from North Carolina, is used for crayons and slate pencils, while the still finer, cryptocrystalline varieties STONES FOR BUILDING AND DECORATION. 47 such as are at present obtained almost wholly from abroad, are used by tailors under the name of " French chalk," and for making the tips for gas burners. Fine compact grades of a somewhat similar rock (agalmatolite) are used extensively in China and Japan for small ornaments. The stone is readily carved in fine sharp lines, and is a general favorite for making the grotesque images for which these countries are noted. Soapstone occurs associated with stratified rocks only in the older formations, and hence the principal beds now known lie in the Appalachian regions in the Eastern United States. The beds, as a rule, are not extensive but occur as lenticular shaped masses of uncertain area intercalated with other mag- nesian and hornblendic or micaceous rocks, frequently more or less admixed with serpentine. The rock, like serpentine, is as a rule traversed by bad seams and joints, and the opening of any new deposit is always attended with more or less risk, as there is in many cases no guarantee that sound blocks of suffi- cient size to be of value will ever be obtainable. (2) SOAPSTONES OF THE VARIOUS STATES AND TERRITORIES. Arkansas. A fine, compact, brecciated steatite occurs some 12 miles north of Benton, Salina County. The supply is stated to be abundant.* California. Soapstone of fine quality is said to occur near Placerville, in El Dorado County ; also in Tuolumne County, near Sonora and Buchanan.f Maine. A large bed of soapstone is stated by Jackson J to * Agriculture and Mineral Resources of Arkansas, 1887. f Eighth Annual Report State Mineralogist of California, 1888. \ First Annual Report Geology of Maine, 1837 p. 79. 48 STONES FOR BUILDING -AND DECORATION. occur on Orr's Island in Cumberland County. The stone is interstratified with micaceous and talcose schists, the strata running N.N.E. and S.S.W., with a dip of 80 W.N.W. The bed is exposed in an outcropping 14 feet wide on the southeast side of the island. The stone is stated to be hard to saw, yet capable of being wrought into excellent slabs for the construc- tion of stoves and firegrates, being very refractory, and not cracking when exposed to intense heat. This bed, so far as the author is aware, has never been worked. Other beds are stated to occur at Jaquish and Harpswell, and which have been wrought to some extent. Maryland. Small areas of soapstone resulting from the alteration of an eruptive enstatite rock are common in Carroll and Montgomery Counties in this State, and have for many years been quarried in a crude and itinerant manner near Sykesville, in Carroll County. The rock on the surface here, as is usual, is badly jointed, and the openings are not of suffi- cient depth to afford much encouragement. The quarried material is sawn up into slabs of small size for foot-warmers and grillers. Massachusetts. Quarries of soapstone have been worked from time to time in Lynnfield and North Dana, in this State. The Lynnfield stone occurs in connection with serpentine. It is soft enough to be readily cut with an ordinary hand-snw when first quarried, but hardens on exposure. When quar- ried, it was used chiefly for stove-backs, sills, and steps. At North Dana the soapstone quarries were opened as early as 1846, and have at times been quite extensively worked. New Hampshire. An extensive bed of fine quality soap- stone was discovered in 1794 at Francestown, in this State, and was worked as early as 1802. Up to 1867 some 2,020 tons had been quarried and sold. In this latter year some 3,700 stoves were manufactured by one company alone. The STONES FOR BUILDING AND DECORATION. 49 business has been conducted upon a large scale ever since. The bed has been followed some 400 feet, and the present opening is some 40 feet wide, 80 feet long, and 80 feet deep Other beds constituting a part of the same formation occur in Weare, Warner, Canterbury, and Richmond, all of which have been operated to a greater or less extent. Five beds of soap- stone also occur in the town of Orford, and an important quarry was opened in Haverhill as early as 1855. It has not, however, been worked continuously.* New York. Soapstone or talc occurs in abundance in Fowler and Edwards, Saint Lawrence County, in this State. It is said to be of good quality, remarkably tough, and very refractory in fire.f North Carolina. Soapstone of fine quality occurs in sev- eral localities in the southwestern part of this State, the national collection showing specimens from 7 miles northeast of Murphy, Cherokee County; from 4^ miles from Green- borough, Guilford County ; from Alamance County ; from Nantehala River, Cherokee County; and from Deep River, Moore County. Of these the Nantehala stone is a pure, nearly white, compact talc, said to be fully equal to the best French chalk. It has been much used as a white earth. The Deep River " soapstone " is a compact variety of the mineral pyro- phylite. This is also used as white earth. Both these stones are shipped in bulk to New York, where they are ground and bolted. The stones from the other localities are of the ordin- ary type of soapstones, but apparently of good quality. Pennsylvania. In the southern edge of Montgomery County, " extending from the northern brow of Chestnut Hill between the two turnpikes, across the Wissahickon Creek and * Geology of New Hampshire, Vol. in., p. 86-88- \ Geology of New York, 1838, p. 206. 50 STONES FOR BUILDING AND DECORATION. the Schuylkill to a point about a mile west of Merion Square," occurs a long, straight outcrop of steatite and serpentine. The eastern and central part of this belt on its southern side " consists chiefly of a talcose steatite," while the northern side contains much serpentine interspersed in lumps through the steatite. Only in a few neighborhoods does the steatite or serpentine occur in a state of sufficient purity to be profitably quarried. On the east bank of the Schuylkill, about two miles below Spring Mill, a good quality of material occurs that has long been successfully worked. It has also been quarried on the west bank of the river about a third of a mile away, and to a less extent on the west bank of the Wissa- hickon, opposite Thorp's Mill. The material is now used principally for lining stoves, fire-places, and furnaces, though toward the end or the last century and the early part of the present one, before the introduction of Montgomery County marble, it was in considerable demand for door steps and sills. It proved poorly adapted for this purpose, however, owing to the unequal hardness of its different constituents, the soap- stone wearing rapidly away, while the serpentine was left pro- jecting like knots or " hob-nails in a plank." * South Carolina. Steatite or soapstone is said to occur in this State in the counties of Chester, Spartanburgh, Union, Pickens, Oconee, Anderson, Abbeville, Kershaw, Fairfield, and Richland. The Anderson County stone is said to have been much used for hearthstones. That of Pickens County is con- sidered of value, but it has been quarried to a very limited extent.f Texas. Soapstone of good quality and inexhaustible in quantity is stated to occur in large veins on the Hondo and * Rep. C 4 , Second Geological Survey of Pennsylvania, pp. 95, 96. f South Carolina, Population, Resources, etc., 1883. STONES FOR BUILDING AND DECORATION. 51 Sandy Creeks, about midway of their courses through Llano County.* Vermont. Most of the steatite of this State is found on the east side of the Green Mountains and near the eastern line of the talcose slate formation, beds of it extending nearly the entire length of the State. The rock occurs usually asso- ciated with serpentine and hornblende. The beds are not continuous and have, as a rule, a great thickness in compari- son with their length. It not infrequently happens that several isolated outcrops occur on the same line of strata, sometimes several miles apart, and in many cases alternating with beds of dolomitic limestones that are scattered along with them. At least sixty beds of this rock occur in the State in the towns of Readsboro, Marlborough, Newfane, Windham, Town- send, Athens, Grafton, Andover, Chester, Cavendish, Balti- more, Ludlow, Plymouth, Bridgewater, Thetford, Bethel, Rochester, Warren, Braintree, Waitsfield, Moretown, Duxbury, Waterbury, Bolton, Stow, Cambridge, Waterville, Berkshire, Eden, Lowell, Belvidere, Johnson, Enosburgh, Westfield, Rich- ford, Troy, and Jay. Of the beds named those in Grafton and Athens are stated to have been longest worked and to have produced the most stone. The beds lie in gneiss. The quarries were piofitably worked as early as 1820. Another important bed is that in the town of Weathersfield. This, like that of Grafton, is situ- ated in gneiss, but has no overlying rock, and the soapstone occurs in inexhaustible quantities. It was first worked about 1847, an d during 1859 about 800 tons of material were removed and sold. The Rochester beds were also of great importance, the stone being peculiarly fine-grained and com- * Second Annual Report Geology of Texas, 1876, p. 26. 52 STONES FOR BUILDING AND DECORATION. pact. It was formerly much used in the manufacture of refrigerators. The quality of the stone is represented to be unusually good and free from impurities.* The bed at New- fane occurs in connection with serpentine, and is some half a mile in length by not less than twelve rods in width at its northern extremity. The soapstone and serpentine are strangely mixed, and the general course of the bed being like that of an irregular vein of granite in limestone. Virginia. Soapstone occurs in this State, according to Professor Rogers,f near the mouth of the Hardware River, both in Fluvanna and Buckingham Counties. There is also a bed of it associated with the talcose slates in Albemarle County, a little west of the Green Mountain. The beds from here extend in a southwesterly direction, passing through Nelson County, where they are associated with serpentine ; thence they cross the James River above Lynchburgh, and present an outcrop about two miles westward of the town on the road leading to Liberty ; also one about two and a half miles westward of New London. Continuing 1 in the o same direction it is seen at the meadows of Goose Creek, where it has been quarried to some extent. Continuing in the same general direction the soapstone again appears in several nearly parallel ranges, of which the most eastern makes its appearance near the Pigg River, in Franklin County, A second belt occurs in the same vicinity near the eastern base of Jack's Mountain ; a third still farther west, about one mile from Franklin Court-house, and a fourth yet more to the west, on the eastern slope of Grassy Hill. The material from near Franklin Court-house is stated to be the best of any of the above. About thirty miles southwest from Richmond, at Chula, * Geology of Vermont, Vol. n., p. 783-91. f Geology of tfce Virginias, p. 79. STONES FOR BUILDING AND DECORATION. 53 in Amelia County, there are outcrops of soapstone said to be of fine quality, and which in former times were quite exten- sively operated by the Indians. They have been re-opened within a few years, and the material is now in the market. Specimens of the stone examined by the writer are by no means pure talc, but carry abundant long brownish fibers of some amphibolic mineral. SERPENTINE, OPHICALCITE, VERB-ANTIQUE MARBLE. (l) COMPOSITION, ORIGIN, AND USES OF SERPENTINE. THE rock serpentine is essentially a hydrous silicate of magnesia, consisting when pure of nearly equal proportions of silica and magnesia with from 12 to 13 per cent of water. The massive varieties quarried for architectural purposes are always more or less impure, containing frequently from 10 to 12 per cent of iron oxides, together with varying quantities of chrome iron (chromite), iron pyrites, hornblende, olivine, minerals of the pyroxene group, and the carbonates of lime and magnesia. The reason for this great diversity in composition lies mainly in the fact that serpentine rarely if ever occurs as an original deposit, but as noted below, is always secondary, a product of alteration of either eruptive or sedimentary rocks rich in mag- nesian minerals. As, however, these rocks in no case consist of pure magnesian silicates, but carry in addition lime, alumina and various metallic oxides, these constituents separate out during the process of change, and recrystallize in veins, streaks and blotches as calcite, dolomite, magnetite, etc., thus produc- ing the common variations in color. The purer varieties are uniformly green or light yellowish, while the commercial forms, 54 STONES FOR BUILDING AND DECORATION. as is well known, are variously streaked and blotched and sometimes brownish, almost black or even of a blood-red color, the different shades, according to Delesse, being dependent upon the amount and state of oxidation of the included fer- ruginous substances. The name Serpentine as applied to this class of rocks is from the Latin serpentinus, a serpent, in allusion to the colors and their spotted or mottled arrangement. The name ophiolite or ophite as sometimes applied to the spotted green and white varieties is from the Greek word c^zY?/?, also meaning a ser- pent, or serpent-like. These rocks are also called ophicalcite by various writers. Precious serpentine is the pure translucent, massive variety of a rich oil green color, like that from Mont- ville, New Jersey. Chrysotile and Amianthus are the names applied to fibrous and silky varieties ; these are utilized as a substitute for asbestus, being less brittle and of finer fiber. The name verd antique (verte antique, or verde antique), antique green, it should be stated, is not applied to the rock of any particular locality, but to any of the green serpentinous marbles used by the ancient Romans, and which were obtained originally from Italy, Greece, or Egypt. The origin of serpentine rocks has long been a matter of dispute among geologists. Recent investigations tend to show that in many cases they result unmistakably from the altera- tion of igneous eruptive rocks, especially the olivine bearing varieties, such as the peridotites. In the varieties ophicalcite, consisting of intermingled serpentine and calcite or dolomite, the serpentine is apparently in all cases derived by a process of hydration from a non-aluminous pyroxene. The theory long ably advocated by Dr. Hunt to the effect that the serpentine occurring intercalated with beds of schistose rocks and lime- stones, resulted from metamorphism of silico-magnesian sedi- ments deposited by sea waters is now very generally abandoned, STONES FOR BUILDING AND DECORATION. 55 and it is doubtful if the substance ever occurs as an original deposit even in the eozoonal forms, but is presumably always secondary.* The following analyses will serve to illustrate the change in composition which takes place in the conversion of (i) olivine, and (2) pyroxene in to serpentine. I n in a be d Silica 41.32$ 42,72# 54,2i5# 42, 38$ 43,48$ Magnesia 54,69 42,52 19,82 42,14 43,48 Lime . . 24,71 Alumina 0,28 0,06 0,59 0,07 Ferric Oxide. ..-. 0,20 0,97 Ferrous Oxide 2,39 2,25 0,27 0,17 Water 0,20 13,39 0,14 14,12 13,04 (a) Olivine, Snarum, Norway; (b) Serpentine derived from the same; (c) Pyrox- ene, Montville, New Jersey; (d) Serpentine, derived from the same; and (in) the theoretical composition of serpentine. This change it will be observed is in the case of the olivine simply a process of hydration an assumption of some 13$ of water. In the pyroxene the process is more complex and consists of a loss in silica, of all the lime which crystallizes out as calcite, and an assumption of nearly 14$ of water. Owing to its softness, which is such that it can be readily carved or turned on a lathe and its beautiful colors when pol- ished, serpentine has long been a favorite with all civilized nations for ornaments and interior decorative work. The rock, however, occurs almost universally in a badly jointed condition, so that blocks of small size only can be obtained, or if large, they are liable to break under pressure or even in process of dressing. (See plate III.) No stone with which the quarry- * The reader is referred to British Petrography by J. J. H. Teall (Dulan & Co., Soho Square, London,) p. 104 for a most excellent historical sketch of this subject. Also to Becker's report on the quicksilver deposits of the Pacific Slope, monograph XIII., U. S. Geological Survey, p. 117. $6 STONES FOR BUILDING AND DECORATION. men have to deal is, as a rule, so full of defects as these ser- pentinous rocks. It is in most cases practically impossible to obtain slabs of more than a few feet in diameter which will not, through flaws or dry seams, fall apart if sawn at all thin, and it can in no case be used in blocks or pillars of any size where more than a very moderate degree of strength is required, since the prevalence of these seams so weakens it as to render it worse than valueless. Every line or vein of different color with which the stone is traversed but marks an old flaw and is a line of weakness. This almost universal characteristic of the stone is one in- vestors will do well to carry in mind ; a total disregard of this trait, due presumably to ignorance, has led to no end of quarry failures. Still another fact worthy of being mentioned, is that however high a lustre the stone may take, or however beautiful it may appear in small pieces, the color is not one that accords readily with its surroundings, and the demand for it for purely decorative work must always be more limited than that for other marbles whose colors are more harmonious. Moreover, the stone is not adapted for polished work in exposed situa- tions, since the different substances composing the body of the stone and filling the veins, and imparting beauty by contrast, will, on exposure, weather unequally. The white and yellowish veins lose their lustre and crumble away, or turn dull yellow, while the whole block becomes seamed and the serpentine itself takes on a greasy lustre mak- ing it as unsightly as it once was beautiful. This unfortunate property of veined stones is further alluded to in the chapter on the Selection of Building Stones (p. 382). For small orna- ments, and in slabs of moderate dimensions for interior decor- ations, serpentine is capable of producing good affects. Too much has been and still is expected from it, and in this, largely, lies the failure that has fallen to the lot of nearly every quarry that has been opened in America. STONES FOR BUILDING AND DECORATION. $? (2) SERPENTINES OF THE VARIOUS STATES AND TERRI- TORIES. California. Inexhaustible quantities of serpentine of a deep green or yellowish color occur in the region round about San Francisco, and often in such situations as to be easily available, as at the head of Market street. So far as observed none of the material is of such a quality as to render it of value for ornamental work, while its gloomy color renders it equally objectionable for purposes of general construction. The rock is also abundant in other parts of the State, but the writer having seen little of the material excepting as displayed in small fragments in the State museum at San Francisco, is obliged to reply mainly upon the statements of others regard- ing their economic value. A body of serpentine varying from dark green to dark mahogany is stated * to occur six or seven miles north-east of lone, near Dry Creek, in Amador County. Other deposits are stated by the same authority to occur near Benicia in Solano County. According to Becker, f serpentine occurs in irregular areas throughout the quicksilver belt of California sometimes in comparatively pure masses and sometimes as one of the mineral constituents of altered sandstones and granular metamorphic rocks. The entire area covered by the rocks of this class is estimated as not less than 1000 square miles, be- tween Clear Lake and New Idria. These Mr. Becker regards not as altered olivine rocks, but as derived from a variety of minerals including even the quartz and feldspar granules in silicious sandstones. * Report State Mineralogist of California, 1888, p. 104. f Geology of the Quicksilver Deposits of the Pacific Slope. Monograph XIII., U. S. Geological Survey, p. 108. 58 STONES FOR BUILDING AND DECORATION, Near the town of Victor, San Bernardino County, are ex- tensive beds of a serpentinous limestone which perhaps may as well be described here. According to the reports of the State Mineralogist * the stone occurs in inexhaustible quantities and blocks of large size are obtainable free from flaws. Samples of the stone examined by the writer vary from light yellowish and greenish to deep green, variously mottled and streaked. The stone has apparently a similar origin to the verdantique of New York State (see p. 65) and is therefore a mixture of cal- careous and serpentinous matter. It is of fine grain, close texture, and acquires a high polish. It is possible that owing to its general lighter and more harmonious colors this stone may prove more successful in our markets than have the majority of verdantique marbles. Connecticut. The serpentine deposits of Connecticut are thus described by Professor Shepard :f " Connecticut prospers, however, in the green marbles of Milford, a material for decoration much more beautiful and highly prized than white marble. These were first detected in 1811. Two quarries were soon after opened, one near the village of Milford, and called the Milford quarry ; the other 2\ miles west of New Haven, and called the New Haven quarry. They were wrought with considerable activity for several years, and furnished an abundance of very rich marble ; but as the work- ing of them was attended with heavy expense from the diffi- culty of obtaining blocks of large dimensions that were per- fectly sound, and from the labor required in sawing and polishing, they were in a few years abandoned, and have for a long time been in a neglected condition. The experiment proved an un- * loth Annual, 1890, p. 528. \ Report on the Geological Survey of Connecticut, by C. U. Shepard, 1837, pp. 101-103. STONES FOR BUILDING AND DECORATION. 59 fortunate one, therefore, not from any deficiency of marble or its lack of beauty for these were both fully admitted but from a want of wealth and taste in the country to sustain the price. It was perhaps an unfortunate thing that the whole of the marble afforded by these quarries v/as denominated verde antique, whereas but a small part of that furnished is entitled to this name. The quarry at Milford is capable of furnishing abundant supplies of this highly valued marble (i.e., the verde antique variety), although, from the circumstance that it occupies nar- row and irregular seams among the veined marble, blocks or slabs of any size must always be dear compared with pieces sawn as formerly, without any regard to its separation from the more common kind. . . . Whenever the attempt to work it is made, it is to be hoped that the same experience of the past will prevent its use for monuments exposed to the weather, for besides the incongruity of its colors compared with the marbles usually employed for this purpose, it soon loses its lustre and emits color from the action of the weather on the grains of magnetic iron ore it contains. The New Haven marble, though destitute of the accidental and in some measure classical value which pertains to the Milford variety, is nevertheless a beautiful thing for decoration. In vivacity of colors and the delicacy of their arrangement it is hardly capable of being surpassed. It may be described as a bluish gray or dove-colored limestone clouded with greenish yellow serpentine, the latter containing black grains and sheet veins of magnetic iron ore. The disposition of the colors is cloud-like, flamed, and veined. It polishes with difficulty in consequence of the magnetic iron it contains, which, though it heightens its beauty, unfits it for exposure to the weather." So far as the present writer is aware these quarries have not 6O STONES FOR BUILDING AND DECORATION. been worked since the time mentioned by Professor Shepard ; i.e., since a few years subsequent to 1811. Delaivare. Serpentine of various shades of green is stated to occur about 6 miles northeast from Wilmington, New Castle County, and also to the westward, near the State line, where Brandywine Creek enters the State line from Pennsyl- vania.* So far as the writer is aware it has never been quarried. Maine. A large bed of serpentine occurs on the northern end of Deer Isle, in Penobscot Bay, in this State. The rock is very massive, and of a dark green, almost black color, some- times streaked and spotted by veins of amianthus and diallage crystals. It Ls indeed almost too dark and somber for orna- mental work, but seems very durable and well adapted for general building purposes. A company was formed some years ago for working this stone, and a shop erected for saws and grinding beds. A considerable amount of material was quarried, but the work was soon discontinued, and had not been resumed at the time of the writer's visit in 1884. The com- pany seem to have fallen into the error of supposing that the stone could be used in long pieces and slabs for window trimmings, and door-posts, but for which, owing to its jointed condition, it is entirely unfitted. The deposit covers a nearly level area of many acres in extent, and lies within a short dis- tance of the shipping wharf. Maryland. In the vicinity of Broad Creek, in Harford County, in this State, occurs a very large deposit of serpentine, which is described by Professor Genth f substantially as follows : * Geology of Delaware, 1841, p. 35. f Geological Report of the Maryland " Verde Antique " marble, etc., in Harford County, Md., by Prof. F. A. Genth, 1875. . STONES FOR BUILDING AND DECORATION. 6 1 " The outcrop of the first or upper bed of green serpentine, of about 500 feet in thickness, can be traced by its outcrop almost the whole distance between the upper ford on Broad Creek and over the hill in a northeasterly direction to a ravine on the same creek, a distance of about 1,800 feet ; it also crosses the creek in a southwesterly direction, but it has not been ascertained how far it extends. The outcrop of the second bed was measured on the top of the hill between the horseshoe of Broad Creek, and found to be about 180 feet, and it is very conspicuous on the west side of the creek. Its full extent was not determined. The rock is a variety of mass- ive serpentine somewhat resembling williamsite, and shows sometimes a slightly slaty structure. It occurs in various shades from a pale leek-green to a deep blackish green, and from a small admixture of magnetic iron, more or less clouded ; rarely with thin veins of dolomite passing through the mass. It is translucent to semi-transparent, exceedingly tough and its hardness is considerably greater than that of marble." An analysis of the deep-green variety gave the following results : Per cent. Per cent. Silicic acid 40.06 Magnesia 39.02 Alumina 1.37 Water 12.10 Chromic oxide 0.20 Magnetic iron 3.02 Niccolous oxide 0.71 Ferrous oxide 3.43 oo.oo Manganous oxide 0.09 Specific gravity 2.668, which denotes a weight of i66f pounds per cubic foot, or practically the same as granite. Specimens of this stone received at the National Museum admitted of a very high lustrous polish, the colors being quite uniformly green, slightly mottled with lighter and darker shades. It is not a true verde antique in the sense in which this name was origin- ally employed. So far as can be judged from appearances, 62 STONES FOR BUILDING AND DECORATION. this is a most excellent stone, and admirably suited for interior decorative work. About 6 miles north of the city of Baltimore, at a locality known as the Bare Hills, occurs an outcrop of a coarse light- green serpentine covering many acres. The rock is quite porous, of a dull light-green color, and unfitted for any kind of ornamental work, but admirably suited for general building, especially in rock-faced and rubble work. At the time of the writer's visit, in the summer of 1885, but a single quarry had been opened, and this was not at the time in operation. The material had been used with excellent effect in the construction of a school-house in the immediate vicinity. The stone occurs in the form of low rounded masses or bosses, and is regarded by Dr. G. H. Williams as an altered peridotite.* The supply is inexhaustible. Portions of the rock carry a very considerable amount of chrome iron, which was at one time mined here quite extensively. In the quarry the rock occurs in a very badly jointed condition, and the blocks are rounded and irregular. Firm blocks several feet in length, which cut up readily into sizes suitable for house walls and similar purposes, can, however, be obtained. Massachusetts. Serpentine exists in Massachusetts in great abundance, particularly in the Hoosac mountain range. " The most extensive bed occurs in Middlefield, in the southern part of the town. This bed can not be less than a quarter of a mile in breadth and 5 or 6 miles long. The colors of the rock are various and its hardness unequal. If wrought, it might supply the whole world. It yields both the precious and the common varieties. There is another bed in the same town, associated with steatite or soapstone. In the west part of Westfield and extending into Russell is found another extensive bed of this *Bulletin U. S. Geological Survey, No. 28. STONES FOR BUILDING AND DECORATION. 63 rock of a much darker color and containing green talc. This has been used in a few instances for ornamental architecture, and has a rich appearance when wrought. " Three beds of serpentine are found in Blanford and another in Pelham, in the southwest part of the town. The color of this last is dark, and the quantity of the talc is considerably large. A large bed occurs in connection with soapstone on the north side of Deerfield River, in Zoar, near the turnpike from Greenfield to Williamstown. Specimens from this place re- semble those from the celebrated localities of this rock at Zoblitz, in Saxony." Two beds of serpentine exist also at Windsor, in this State. " A locality of noble or precious serpentine has long been known to exist in Newbury, 2^ miles south of Newburyport, at an abandoned lime quarry called the ' Devil's Den.' Only small masses can be here obtained, but when polished they will compare with any in the world for beauty. Perhaps the most interesting and important bed of this rock that has as yet been found in the State is that at Lynnfield, in Essex County. The bed has been traced from a point near the center of the town some 2 or 3 miles in a northeasterly direction."* When first quarried the stone is said to be so soft that it can be cut with a handsaw and very readily turned on a lathe. New Jersey. A beautiful deep-green and oil yellow, often translucent serpentine, occurs, associated with dolomite, at Montville, in this State. Only pieces of small size are obtain- able, and though of exceptional beauty the stone has never been utilized except for cabinet specimens. The stone has been shown by the writer to result from the alteration of segregation masses of a non-aluminous pyroxene imbedded in the dolomite.f * Hitchcock's Geology of Massachusetts, Vol. I., p. 158. f Proceedings U. S. National Museum, 1885, p. 105. 64 STONES FOR BUILDING AND DECORATION. New Mexico. A banded and mottled light and dark green impure serpentinous rock occurs in the form of a narrow dike just north of the Gila River, about half way between Silver City and the Arizona line in this territory. The colors are good, and the stone seems well adapted for both orna- mental work and general building. It is known commercially as ricolite, from the Spanish word rico, rich, in allusion to its rich green color. . The following analysis, if correct, shows the the stone to be much more impure than one would be led to suppose from a casual inspection : Silica 43. Alumina i6.< Magnesia 23.; Water I Lime 2.22$ Soda and Potash 2.30$ Iron oxides . . . . traces. Total 99.98$ A closely related and very unique rock which may answer well for certain forms of ornamentation also occurs in this vicinity. The main mass of this rock, so far as the writer has seen it, is composed of a finely granular pyroxenic mineral of a deli- cate light blue color. Throughout this are scattered irregular sporadic areas of yellowish green serpentine resulting from the hydration of the pyroxene. The effect is decidedly unlike anything I have seen elsewhere, and the developments of the quarry may be awaited with interest.* New York. At Moriah and Port Henry, in Essex County,, in this State, there has been quarried from time to time under * The writer is indebted to Mr. J. H. Huntington for whatever information he possesses relative to these stones. STONES FOR BUILDING AND DECORATION. 65 the name of ophite marble, a peculiar granular stone consisting of an intimate mixture of serpentine, dolomite and calcite inter- spersed with small flecks of phlogopite. This stone, which is an altered dolomitic and pyroxenic limestone,* seems nearly free from the numerous dry seams and joints that prove so objectionable in most serpentines, and can be obtained in sound blocks of fair size. The serpentinous portions are deep green in color, while the calcareous granules are faint water blue, or whitish, affording a very pleasing contrast. In certain of the outcrops a mineral of the pyrite group occurs, which is of course deleterious, as liable to oxidation, and it is said to be the presence of this mineral that led to the abandonment of some of the older quarries. Other reasons have doubtless contri- buted. Among these may be mentioned the fact that at few of the openings, as seen by the writer, can blocks of large size and homogeneous texture be obtained, every few feet showing large and irregular nodules of deep greenish and yellowish serpentine, calcite, or white pyroxene, and often large scales of graphite, which would prove nearly as objectionable on a polished surface as do the dark patches in many of our granites. Blocks being quarried at the time of my visit (1888) showed, however, a very even granular texture of nearly equal parts of serpentine, calcite and dolomite in grains of from one eighth to one-fourth of an inch in diameter, forming an aggregate quite granitic in appearance at a slight distance. The stone polishes well, and is said to be durable. In the quarry bed, where the stone had been exposed for ages, it was noticed that the calcite had weathered out on the surface, leaving the serpentine protruding in small greenish knobs. The stone has been quoted in some of the older quarry price-lists at $6.00 a cubic foot for the best monumental stock. * Proceedings U. S. National Museum, Vol. XII., 1889, p. 595. 66 STONES FOR BUILDING AND DECORATION. In Warren County a stone of this same general nature occurs, and which has in times past been quarried near the town of Thurman. This stone, as shown by samples in the National Museum, is composed of about equal parts snow-white calcite and light yellowish-green serpentine in flecks and patches from one-sixteenth to one-fourth of an inch in diameter. The text- ure, as in the Essex County stone, is, however, by no means uniform, and the large blocks frequently show large and very irregular patches of deep lustrous green serpentine with snow- white, and still unaltered pyroxenic nuclei, the serpentine here, as is the case with that of Montville, (New Jersey,) and the last mentioned, being secondary after a non-aluminous pyroxene. Geologically these beds are of interest as having furnished frag- mental remains of the once-problematic organism, the so-called Eozoon Canadense.* It is stated f that the largest and most valuable deposit of serpentine in the State is found in the towns of Gouverneur, Fowler, and Edwards, in St. Lawrence County. The rock is said to be massive and sound, and remarkably free from the checks and flaws usually so profusely developed in rocks of this class. In Pitcairn, in the same county, there is also a fine de- posit of serpentine of the variety commonly called precious. The calcareous spar is white or grayish-white, and forms a handsome background for the translucent serpentine. The quality of the rock is said to be excellent and free from natural flaws and fissures. Serpentine also forms the main range of hills on St'aten Island, and extends from New Brighton to a little west of Richmond, a distance of 8 miles. The rock assumes a variety of colors, from almost black to nearly white. * See on the Ophiolite of Thurman, Warren County, New York, with remarks Dn the Eozoon Canadense, by the writer in American Journal of Science for March, 1889. f Geology of New York, 1838, p. 205. STONES FOR BUILDING AND DECORATION. 6? North Carolina. The massive varieties of serpentine are found in many localities. The best appears to come from the neighborhood of Patterson, Caldwell County. It has a dark, greenish-black color, and contains fine veins of the yellowish- green fibrous and silky chrysotile, and admits of a fine polish ; greenish-gray massive serpentine, also with seams of greenish and grayish white chrysotile is found at the Baker mine in Cald- well County, at which place are also found the varieties mar- molite and picrolite ; this last also occurs abundantly in the Buck Creek corundum mine, Clay County. Dark green ser- pentine has been observed in the neighborhood of Asheville, in Buncombe County, in Forsythe and Wake Counties. A grayish or yellowish green serpentine occurs in Caldwell, Wilkes, Surry, Yancey, Stokes, Orange, and Wake Counties, and in the chryso- lite beds of Macon, Jackson, Yancey, Mitchell, Watanga, Burke, and other counties. It results from the decomposition of the chrysolite.* The writer has seen but a single sample of these rocks, and hence can express no opinion regarding their value. Pennsylvania. Serpentine is a common rock in several coun- ties in the southeastern part of this State, but so far as the writer is aware none of the outcrops furnish material of such a nature as to be suitable for decorative work. A small area of the stone occurs in the extreme southeastern part of Bucks County ; three lines of outcrops occur in the southwestern part of Montgomery County, passing through Lower Merion into Delaware County near Radnor. From the southern corner of this township numerous isolated outcrops occur throughout a broad belt extending southwesterly through the townships of Marble, Newtown, Middletown, Providence, Aston, Concord, and Birmingham. In the words of the State Geologist, "A serpentine belt extending from Chester Creek, at Lenni (or * Geology of North Carolina, 1881, p. 57. 68 STONES FOR BUILDING AND DECORATION. Rockdale), past Media to Darby Creek in Radnor township (nine miles) has been quarried for building stone. It consists of separate and parallel outcrops; at least twenty-seven other local exposures of serpentine in various townships are marked upon the map, all of them in the Chestnut Hill schist area, and apparently belonging to the upper part of that series."* A long range of serpentine is also found in Williston and East Goshen townships in Chester County, and a still more exten- sive belt in the extreme southern part of the county, in Elk and Nottingham townships. This last extends over into Lan- caster County, where there are two belts separated by a belt of schist, the southernmost " running along the Maryland line and holding the famous Woods chrome mine, which at one time produced all the chrome in the world, and in busy times as high as 500 tons a month. The serpentine is here unstratified, 1000 yards wide, striking N. 78 E. with sandy chloritic slates north of it and hornblendic gneiss and syenite south of it." In Lower Merion township (Montgomery County), the ser- pentine has been quarried from exposures near the Philadelphia and Reading Railroad. The rock here is compact, dark green- ish in color, and suited only for general building. It is associ- ated with steatite and is regarded by Mr. T. D. Rand f as resulting from the alteration of an enstatite rock as is also that of Radnor township. Of the areas above mentioned those of Chester County have so far proven most important from our standpoint, and extensive quarries have for some years been worked near the town of West Chester. The stone here, as usual, occurs only in a badly jointed condition (see illustration plate III.), but owing to its softness, and consequent readiness with which it * Geol. Surv. of Penna., Rep. x., Geol. Atlas and Counties, p. XLVII. \ Annual. Report Pennsylvania Geological Survey, 1886, Part iv. PLATE III. SERPENTINE QUARRIES, CHESTER COUNTY, PENNSYLVANIA. To face page 68. STONES FOR BUILDING AND DECORATION. 69 can be worked, it has come into very general use for building purposes, particularly in New York, Philadelphia, Baltimore, Washington and Chicago. The buildings of the University of Pennsylvania, the Academy of Sciences, and some twenty churches in Philadelphia, are of this stone. The use of the stone in cities has not been long enough continued to furnish accurate data regarding its durability, but it is stated that houses erected in the vicinity of the quarries one hundred and fifty years ago show the color of the stone to-day as fresh as when first quarried. The writer's personal observations are, however, to the effect that in a majority of cases many of the blocks exposed in a wall turn whitish, or at least fade to a lighter green. Such a change can scarcely be considered detrimental. Although the stone has been upon the general market only about ten years it has acquired an excellent reputation. To the writer it seems that in the majority of cases very poor taste has been shown on the part of the designers, very many of the buildings being anything but beautiful from an architectural standpoint. The almost universal practice of using a light, yellowish-gray sandstone for the trimmings in houses of this material should also be condemned, since the contrast is not sufficient nor satisfactory. The origin of the Chester County stone, as with serpentines in general, has been a subject of considerable discussion. As long ago as 1862 Dr. Genth* advanced the opinion that the Texas, Lancaster County, stone originated by the alteration of asbes- tus. Prof. Frazer,f in his work on the geology of southeast- ern Pennsylvania considered it as a modification of the Huron- * American Journal of Science (2) 33, p. 202. f Theses Presentees a la Faculte des Sciences de Lille, Universite de France, 1882; also Rep. C 4 Second Geol. Survey of Penna., 1883. ?O STONES FOR BUILDING AND DECORATION. ian schists of the region. Prof. Chester, however, who has since studied the rock with the aid of the microscope and thin sections, regards it as derived from a tremolite rock carrying accessory olivine, the tremolite itself being secondary after pyroxene, and the rock mass as a whole eruptive through the Azoic schists, rather than an integral part of that formation.* A beautiful and deep lustrous green variety susceptible of a high polish and known as Williamsite was found in abundant small pieces during the working of the Fulton township chrom- ite mines. Excepting as polished specimens for mineral cabi- nets the material was never utilized. A narrow belt of a light oil yellow to deep green serpentine occurs associated with the beds of limestone on the south- western flank of Chestnut Hill, near Easton, in Northampton County. The stone evidently originated from the alteration of a white tremolite rock with which it is associated.! The serpentine as here found never occurs in masses of such size as to be of economic value, though of considerable interest to mineral collectors. Texas. Serpentine of a dark green color and fitted for either building or ornamental work is stated to occur on Crab Apple Creek in Gillespie County.J Vermont. The bed of talcose schist that extends in a gen- eral northern and southern direction throughout the entire length of central Vermont bears numerous outcrops of ser- pentine or of serpentine in combination with dolomite, but which, so far as the writer is aware, have been quarried only in Roxbury and Cavendish. The quarry at Cavendish was worked very early, having been opened about 1835, before * Annual Report Geological Survey of Penna. for 1887, f Proc. U. S. National Museum, Vol. XII., 1889, p. 599. J First Report Geological and Mineralogical Survey of Texas, 1888, p. 63. STONES FOR BUILDING AND DECORATION. /I there were adequate means of transportation of the quarried stone or there was any sufficient demand for so expensive a material. The methods of working and polishing the stone were, moreover, so little understood that very poor results were obtained and the works were shortly discontinued as a conse- quence. In Roxbury the American Verdantique Marble Company early opened quarries and erected a mill for sawing. The business was pushed quite vigorously for a time ; but, owing to several causes, probably the same as the first enumerated, the works were shut down in 1858, and have not since been re- opened. A considerable quantity of the material was taken out for the interior decorations of the United States Capitol extensions, but for some reason it was never used. The Roxbury stone is one of the most beautiful of all our serpentines and the best adapted for all kinds of interior deco- rative work. The colors are deep, bright green, traversed by a coarse net-work of white veins. It is designated by Hunt* an ophiolite, and is stated by him to be a mixture of serpen- tine, talc, and ferriferous carbonate of magnesia. It acquires a smooth surface and beautiful polish, and it is a serious com- ment upon American taste that there is not sufficient demand for the material to cause the quarries to be re-opened. At Cavendish the railroad now passes within one-half mile of the quarry and good water-power is close at hand, while the Rox- bury quarry is within 30 rods of the railway station. The rock lacks the brecciated structure characteristic of most foreign verd-antique, but compares more closely with the variety known as Verde di Genova than with any other with which the author is acquainted. Among the other localities in this State * T. S. Hunt, on Ophiolites, American Journal of Science, vol. xxv. p. 239 ; second series, p. 226. 72 STONES FOR BUILDING AND DECORATION. in which serpentine occurs may be mentioned Richford, Mont- gomery, Jay, Troy, Lowell, Middlesex, Wailsfield, Warren, Rochester, Ludlow, Windham, Wadsborough, and Dover. Of the Lowell stone it is stated * that two ranges of serpen- tine occur, commencing near the headwaters of the Missiseo and extending nearly to Canada. " For the richness and num- ber of the varieties it would not seem possible that they can be surpassed, while their extent, amounting to 20 or 30 square miles, is beyond the possible demand of all future ages. They are exhibited in several precipitous ledges, which are easy of access and of being worked." Concerning the locality at Troy, the same authority states : " Elegant varieties are numerous, among which are most con- spicuous the very bright green noble serpentine, which covers most of the numerous jointed faces with a coat of one-eighth to one-half of an inch thick, and the spotted varieties. Num- erous seams may render it difficult to obtain large slabs, but smaller pieces, suitable for a great variety of ornamental pur- poses, may be obtained, of great beauty and in any quantity." (3) FOREIGN SERPENTINES. Canada. Serpentine of a pale green color, marked with spots and clouds of a rich brown due to disseminated iron pro- toxide, and forming a fine ornamental stone occurs in Gren- ville and in Burgess in the Province of Quebec. Other rocks of this class occur in the towns of Melbourne, Orford, St. Joseph, and at Mt. Albert in Gaspe.f So far as the author is aware, these have been as yet but little quarried, though seem- ingly very promising. England. None of the American serpentinous rocks now * Geology of Vermont, 1861, vol. I. p. 544. f Geology of Canada, 1863. STONES FOR BUILDING AND DECORATION. 73 known can compare in point of beauty, in variety and ele- gance of colors, with those of the Lizard district in Cornwall, England. A series of polished blocks of these in the national collections at Washington show the prevailing colors to be dark olive green with veins, streaks, and blotches of greenish white, chocolate brown, and blood red. The green varieties are often spotted by ill-defined flakes of a " silky bronzitic mineral." The rock is softer than the serpentine of Harford County, Maryland, but takes an equally good surface and polish, and works much more readily. It is stated by Hull* to be obtain- able in blocks from 7 to 8 ,feet in length and from 2 to 3 feet in diameter. According to this same authority, the stone is admirably adapted for interior decorations and is now being used for ornamental fonts, pulpits, small shafts, and pilasters, as well as for vases, tazza, and inlaid work. Considering the remarkable beauty and the variety of colors displayed by this stone, it seems strange that it should not have found its way more extensively into American mar- kets. The rock is regarded by Bonneyf as an altered intruded igneous rock, rich in olivine (peridotite). Ireland. The only Irish serpentines which have achieved any notoriety in America, are the so-called Connemara greens and which occur according to Mr. G. H. Kinahanj: only in the west of County Galway. These are classed by this authority as ophiolites and ophicalcites. They vary in color from light to dark green, either uniform or clouded, the majority being variously mottled, streaked, and variegated. The rocks occur * Building and Ornamental Stones, p. 102. f Quar. Jour. Geol. Soc. of London, 1877, p. 884. $ Economic Geology of Ireland. Jour. Royal Geol. Society of Ireland, vol. vin. (new series), part II. p. 152. 74 STONES FOR BUILDING AND DECORATION. in one group of strata, once continuous, but now more or less disconnected and isolated by faulting. In Streamstown Bay Valley is a continuous narrow band of the rocks over three miles in length, and which furnishes a great variety of beautiful material utilized in the manufacture of brooches and various articles of vertu. The stone found in the American market seems to have been brought from quarries near Lissoughter, in this county. The rock here is in general uniform or clouded green, some of it being dark, but at the same time translucent. Very good- sized stones are obtainable, but in rough unshapely blocks. The largest column yet obtained from these quarries measured nine feet nine inches in length, and is in the mansion of Lord Ardilann, at St. Anne's, County Dublin. Writing of these stones Mr. Kinahan says that at one time there was a considerable demand for the Connemara greens, " but unfortunately for the reputation of the stone, architects would insist on using them for outside decorations, and con- sequently, not through any real inferiority in the stones, they soon weathered and became unsightly. Thus was generated a most undeserved prejudice against the green marbles, which when used in their proper sphere as inside work, cannot be sur- passed in beauty or elegance." Italy. The principal serpentinous rocks of Italy are the ophicalcites of Pegli and Pietra Lavezzara, near Genoa, and of Levante, and the true serpentine of Tuscany. The Verde di Pegli is a breccia consisting of deep green fragments of serpen- tine cemented by light green calcite. The contrast of colors thus produced is said to be very pleasing. The Verde di Geneva stone from quarries at Pietra Lavezzara is also a. breccia consisting of green, blackish green, brown, or red ser- pentine fragments with an abundant cement of white or green- ish calcite. It has been quarried from time immemorial, and STONES FOR BUILDING AND DECORATION. ?$ is largely used in France where it is known as Vert de Genes. Its selling price at Turin is about 20 cents per cubic foot. The ophicalcite of Levante is a breccia like the preceding, the frag- ment being of a violet or wine red color. It is difficult to work but acquires a good polish. The Italian name for the stone is rosso or Verde di Levante; though sometimes called granito di Levante. The Tuscany serpentine from quarries near Prato is known commercially as Verde di Prato. The stone is of a deep green color, carrying crystals or nodules of diallage and is traversed by a net-work of fine lines giving it a brecciated appearance. It contains also veins of noble serpen- tine of a clear greenish or whitish color. It is softer than ordinary serpentine and acquires only a dull polish, but works very readily. The dark green variety is most valued, and having been used in ancient monuments is frequently called the Nero antico di Prato.* This stone is stated by Hull to be subject to rapid decay when exposed to atmospheric influences. GYPSUM : ALABASTER. This can scarcely be considered a building-stone, and it is used only to a small extent for ornamental purposes. We may, however, devote a little space to the subject. (l) COMPOSITION AND USES OF GYPSUM. Pure gypsum is composed of the sulphate of lime and water in the proportions of about 79.1 per cent of the former to 20.9 per cent of the latter (ante, p. 26). Three varieties are com- mon : (i) crystallized gypsum or selenite, which occurs in broad, flat, transparent plates sometimes a yard in diameter and of value only as mineral specimens and for optical pur- * Delesse, pp. 77-79. 76 STONES FOR BUILDING AND DECORATION. poses ; (2) fibrous gypsum, which includes the variety satin spar used for making small ornaments ; and (3) massive gyp- sum, which includes the common white and clouded varieties used in making plaster, and the pure, white, fine-grained variety alabaster.* (2) LOCALITIES OF GYPSUM IN THE UNITED STATES. The principal -localities of gypsum in the United States as given by various authorities are in New York, Ohio, Illinois, Iowa, Michigan, Virginia, Tennessee, Arkansas, and Texas, where it occurs in extensive beds and usually associated with salt springs. It is also found associated with Triassic deposits in the Rocky Mountain region. Handsome selenite and snowy gypsum are also stated to occur near Lockport and Camillus, N. Y., in Davidson County, Tennessee, and in the form of rosettes in the Mammoth Cave of Kentucky. According to G. F. Kunzf the ornaments of satin spar sold at Niagara Falls and other " tourist places " are nearly all im- ported from Wales, through some few of the common white variety are cut from the beds of this stone found in the vicin- ity. The Italian alabaster is used extensively in making stat- uettes, but the common varieties found in this country and Nova Scotia are used chiefly for land plaster and as plaster of paris, or stucco. So far as the writer is aware, the gypsum quarried at Fort Dodge, Iowa, is the only one that has been at all used for structural purposes in this country. According to Dr. White ;f several residences, a railway sta- tion, and other minor structures, including a large culvert, have been built of gypsum at this place. In the construction * Much of the material popularly called alabaster is in reality travertine (see p. 116). f Min. Resources of the United States, 1883-84, p. 77. ^ Geol. of Iowa, vol. II. p. 302. STONES FOR BUILDING AND DECORATION. 7/ of the culvert the lower courses that came in contact with the water were of limestone, as the gypsum had proven slightly soluble and hence less durable in such positions. The stone is regarded by Dr. White as very durable in ordinary situations, and the ease with which it can be worked renders it preferable to the limestones in the immediate vicinity. The method of quarrying is to bore holes with a common auger and then blast by means of powder. The blocks are then trimmed to the proper size and shape by means of common wood-saws and hatchets or axes. (3) FOREIGN GYPSUM AND ALABASTER. England. An English alabaster, white, variously clouded and streaked with dull brownish red has been introduced into the New York markets, and has been used in the bank coun- ters of the Equitable Building on lower Broadway. The stone is altogether too soft for use in such exposed situations. It is said to be from quarries in Devonshire. Italy. Alabaster of the finest quality occurs in several parts of Italy, particularly at Miemo, in Tuscany, Fontibagni, and Castellina, and at Aosta, in Piedmont. The purest and best variety is, however, from Valdi Marmolago, near Castellina.* Some of these are very extensively worked, the clouded vari- eties being made into vases and other objects, while the pure white varieties are made into statuettes. In this form they are sold in considerable quantities in this country, passing under the name of Florentine marbles. As prepared for the market these are indistinguishable from true marble by any but an expert, and it is safe to say a large number of people are yearly impos- ed upon. Should one have reason to suppose that this article is being imposed upon him for true marble he has but to try * Hull, op. cit. p. 165 78 STONES FOR BUILDING AND DECORATION. the object in some obscure part with the thumb-nail. Alabas- ter is readily scratched or indented in this manner while marble is not affected. Another test is to apply a dilute acid. True marble will dissolve and effervesce briskly, while the alabaster remains unchanged. Besides being softer, and hence more liable to injury, these alabaster objects are inferior to those of marble in that they are more easily soiled and are difficult to cleanse. It is stated* that the Italian alabaster is, when first quarried semi-transparent, and that it is wrought while in this state. It is then rendered white and opaque (like marble) by placing the objects in a vessel of cold water which is slowly raised to the boiling point. It is then allowed to cool to a temperature of about 70 or 80 Fahr. when the objects are moved and wiped dry. At first they appear little changed by their baptism, but gradually assume the desired color and opacity. Spain. Beautiful white and variegated alabaster occurs in the province of Guadalajara and Saragossa. LIMESTONES AND DOLOMITES. (l) CHEMICAL COMPOSITION AND ORIGIN. The name limestone as commonly applied is made to include a large and widely varying group of rocks, differing from one another in color, texture, structure and origin and with but the one property in common of consisting essentially of carbonate of lime. A pure limestone should consist only of carbonate of lime. In point of fact, however, none of our nat- ural stones are chemically pure, but all contain a greater or less amount of foreign material either chemically combined or as admixed minerals. The more common of these foreign sub- * Appleton's Dictionary of Mechanics, vol. n. p. 387. STONES FOR BUILDING AND DECORATION. 79 stances are carbonate of magnesia, carbonates and oxides of iron, silica, clay, bituminous matter, mica, talc and minerals of the hornblende or pyroxene groups. The presence of these substances gives rise to a variety of shades and colors among which water-blue, green, yellow, pink, red, and all shades of gray to black are common. The yellow, pink and red colors in such cases are due, as a rule, to iron oxides, while the various shades of blue-gray, gray and black are due to the carbona- ceous matter derived from organic remains. The green color of some of the Vermont marbles appears to be due to the presence of talc. Limestones are ordinarily regarded as originating as chemi- cal deposits, or from the consolidation of calcareous remains of marine animals. Many beds, as for instance the Indiana oolites, are products of a combination of these processes. The shells of dead mollusks, corals and crinoids were tumbled about by the waves until ground into grains of calcareous sand, about and around each of which were subsequently deposited from solution the successive coats of lime as shown in Fig. 2 on. Plate II. It is very probable that few of our limestones were wholly derived directly from organic remains, but are in part at least chemical deposits. The alternation of beds of snow-white, blue-gray, greenish and almost black layers, as in the Vermont quarries may perhaps be best explained on the assumption that the white layers resulted as deposits from solution, while the darker layers are but beds of indurated shell mud and sand colored by the organic impurities they contained at the time they were first laid down. Limestones occur in stratified beds among rocks of all geological ages, from the Archaean to the most recent. The majority of those used for building and ornamental work belong either to the Cambrian, Silurian, Devonian, or Carbo- niferous ages. So STONES FOR BUILDING AND DECORATION. (2) VARIETIES OF LIMESTONES AND DOLOMITES. The following list includes all the principal varieties of limestone popularly recognized, the distinctions being founded upon their structure, chemical composition, and mode of origin : Crystalline limestone. Marble. A crystalline, granular ag- gregate of calcite crystals. The crystals are usually of quite uniform size in the same marble, but often vary widely in those from different localities. The fine grained white varieties which appear like loaf sugar are called saccharoidal. Common statuary marble is a good example of this variety. Compact Common Limestone. A fine-grained crystalline ag- gregate which to the eye often appears quite homogeneous and amorphous. It is rarely pure, but contains admixtures of other minerals, giving rise to many varieties, to which particular names are given. Lithographic Limestone is an extremely fine- grained crystalline magnesian limestone, with a small amount of impurities, and of a drab or yellowish hue. Bituminous lime- stone contains a considerable proportion of bitumen, caused by decomposing animal or vegetable matter. Its presence is easily recognized by the odor of petroleum given off when the rock is freshly broken. Hydraulic limestone contains 10 per cent and upward of silica, and usually some alumina. When burned into lime and made into mortar or cement it has the property of setting under water. Oolitic limestones are made up of small rounded concretionary grains that have become cemented to- gether to form a solid rock. These little rounded grains re- semble the roe of a fish ; hence the name, from the Greek word MOV, an egg. Where the grains are nearly the size of a pea the rock is called pisolite. ' Travertine, or Calc Sinter, is limestone deposited by run- ning streams and springs. It occurs in all gradations of texture Sl'ONES FOR BUILDING AND DECORATION. 8 1 from light flaky to a compact rock fit for building. A light porous calc sinter has been deposited by the Mammoth Hot Springs of Yellowstone National Park, some of which is nearly pure carbonate of lime and snowy white in color. Travertine occurs in great abundance at Tivoli, in Italy, from whence it was quarried in building ancient Rome. The exterior of the Amphitheatrum Flavium, or Colosseum, the largest theatre the world has ever known, was of this stone, as was also the more modern structure of St. Peter's, in the same city.* The Latin name of the stone was lapis Tiburtinus, of which the word travertine is supposed to be a corruption. Stalactite and stalagmite are the names given to the deposits of limestone on the roofs and floors of caves. Such are often beautifully crystalline and colored by metallic oxides, giving rise to beautiful marbles, which are incorrectly called onyx, as are also the travertines from which they differ only in method- of deposition. Fossilferous Limestones. Many limestones are made up whol- ly or in part of the fossil remains of marine animals, as is shown in the accompanying figure (p. 82), which is drawn from a mag- nified section of a limestone of the Cincinnati group from near Hamilton, Ohio. In some cases the remains are retained nearly perfect ; again the entire fossil may have been replaced by crystalline calcite. In other instances stones are found which are made up only of casts of shells, the original shell material having decayed and disappeared, as in the Eocene limestone from North Carolina. Many of the most beautiful marbles belong to the group of fossil limestones, as, for instance, the red and white variegated Tennessee marbles. Crinoidal limestones are made up of fossil crinoidal fragments. t Hull, Building and Ornamental Stones, pp. 279, 281. 82 STONES FOR BUILDING AND DECORATION. Shell limestones or shell sand-rocks as they are called by some authorities, are made up of shells usually much broken, though sometimes almost entire. The well-known coquina from Saint Augustine, Florida, is a good illustration of this variety. Coral rock is of the same nature, excepting that it is composed of fragments of corals. Chalk is a fine white limestone composed largely of the minute shells of foraminifera. Magnesian Limestones ; also called Dolomitic Limestones. Under this head are included those limestones which contain 10 per cent and upwards of carbonate of magnesia. They may be finely or coarsely crystalline ; light, porous, or com- pact ; fossiliferous or non-fossiliferous ; in short, may show all the variations common to ordinary limestones, from which STONES FOR BUILDING AND DECORATION. 83 they can usually be distinguished only by chemical tests. Many marbles are magnesian, as will be noticed by reference to the tables. When the carbonate of magnesia in a limestone rises as high as 45.65 per cent the rock is no longer called magnesian limestone, but Dolomite.* This in its typical form is a crystalline granular aggregate of the mineral dolomite, and is usually whitish or yellowish in color. It can in its typical form be distinguished from limestone by its increased hardness (3.5-4.5) and specific gravity (2.8-2.95). It is also less soluble, being scarcely at all acted on by dilute hydrochloric acid. Dolomite shows all the peculiarities pertaining to limestones, both in color and texture, and a chemical analysis is often required to distinguish between them. The pure white marble from Cockeysville, Maryland, is a dolomite, but by the eye alone can scarcely be distinguished from the white crystalline limestones (marbles) of Vermont. The red-mottled marbles of Malletts Bay, Vermont, are also dolomites, as are the white marbles of Lee, Massachusetts, and Pleasantville, New York. In composition there is no essential difference between a limestone or dolomite and what is popularly called a marble, but for convenience sake the subject will be here treated in two parts, the first to include such of this class of rocks as are put upon the market as marbles, and the second the rocks of the same composition, but unfit for finer grades of building and ornamental work and known popularly as simply limestones. (3) LIMESTONES AND DOLOMITES. MARBLES. Under the head of marbles, then, are here included all those rocks consisting essentially of carbonate of lime (limestone) or *So called after the French geologist, Dolomieu. 84 STONES FOR BUILDING AND DECORATION. .carbonate of lime and magnesia (magnesian limestone and dol- omite) that are susceptible of receiving a good polish and are suitable for ornamental work. Alabama. Beds of marble of great beauty are stated to occur along the Cahawba River in Shelby County of this State. The colors enumerated are gray with red veins, red and yellow, buff with fossils, white crystalline, clouded with red and black. A black variety veined with white occurs on the road from Pralls Ferry to Montevallo and on Six Mile Creek. Other good beds are- stated to occur on the Huntsville road about 19 miles from Tuscaloosa and at Jonesborough, the latter rock being compact and of a red and white color ; the same strata occurs at Village Springs. On Big Sandy Creek good marbles occur similar to those on the Cahawba.* None of the above are actively quarried, and the writer has had the opportunity of examining but a single specimen, that a small block of fine and even texture, pure white color and excellent quality, said to be from near Talladega. Arkansas. According to Professor Brannerf marbles occur throughout the northern part of this State.. They are of Lower Silurian age, and vary in color from red to light pink, mottled and white. The beds are from ten to one hundred or more feet in thickness. They begin in Independence County about twenty miles northeast of Batesville, and cross the State west- ward and northward in a belt nearly or quite three miles wide. This belt passes just north of Batesville, north of Mountain View, north of Marshall and on west by way of St. Joe into Boone and Carroll Counties. On the banks of some of the streams traversing this region great perpendicular walls of these marble beds are exposed. * Geology of Alabama, First Biennial Report, 1849, p. 45. f Stone, Indianapolis, Indiana, Oct. 1880. STONES FOR BUILDING AND DECORATION. 85 Such exposures occur on White River where the stone might be quarried advantageously and loaded upon boats. These stones can be obtained in blocks as large as can be handled, while their colors make them desirable both for architectural and ornamental purposes. The ease with which they can be quarried and dressed is also in their favor. At present railroad facilities for transportation are almost entirely lacking. California. It has been stated that owing to the violent geological agencies that have been in operation since the for- mation of the marble deposits in this State the stones are found to be so broken and shattered in nearly every case, that it is impossible to obtain blocks of large size free from cracks and flaws.* The State is nevertheless not lacking in desirable material. Near Indian Diggings, in Eldorado County, there occurs a fine-grained white, blue-veined marble that closely resembles the Italian bardiglio, from the Miseglia quarries, but that the groundmass is lighter in color. It has been used only for grave-stones and to but a slight extent at that. In Kern County are deposits of marble of various shades, but all so broken and shattered on the surface as to be very difficult to work. Near Colfax, in Placer County, are also beds of a dark blue- gray mottled magnesian limestone that takes a good polish and might be utilized as marble. Other deposits occur in Los Angeles, Monterey, Nevada, Butte, Humboldt, Tuolumne and Plumas Counties. At Colton, in Los Angeles County the marble beds are described by Prof. Jacksonf as affording pure white clouded with gray and grayish black finely mottled with * Report of Tenth Census, 1880, vol. x. p. 279. \ Seventh Annual Report State Mineralogist of California, 1887, p. 212. 86 STONES FOR BUILDING AND DECORATION. white varieties, the clouded white being the most abundant. This is stated to be a medium grained granular stone, homo- geneous in texture quite sound and strong and taking a good polish. Chemical tests show that the stone is composed of a mixture of calcite and dolomite granules. This not only renders the production of a perfect surface and polish more difficult than would otherwise be the case, but will also cause it to weather unevenly (see p. 381). The clouding of the marble and the dark gray colors are here due to scales of graphite. At the foot of the Inyo Mountains in Inyo County, about five miles north of the town of Keller, there occurs an extensive bed of dolomite in which within a few years marble quarries have been opened. The strata here are upturned at an angle of 75 to 80 and the beds superficially seamed and cracked to such an extent that large blocks on the immediate surface are unobtainable. Although the quarry openings are as yet shal- low the indications are, however, that these defects soon disap- pear, and at no great depths sound blocks of any size that can be handled may be obtained.* The stone at the various outcrops now exposed is quite variable. At one of the openings it is pure snow white, fine grained and equal in texture to Italian marble, but much harder, firmer and more compact. But a few hundred yards from this is an opening which seems destined to furnish some of the most unique and yet beautiful stone thus far produced in America. In texture this is of the same quality as the last, but the white groundmass is injected in every direction with blotches, streaks and finely divided branching and feathery dark brown nearly black dendritic or fern-like markings presumably caused by oxide of manganese and which added to occasional blotches of Siena yellow produce an effect that * Tenth Annual Report State Mineralogist, 1890. STONES FOR BUILDING AND DECORATION. 87 must be seen to be appreciated. Still a third variety is Siena yellow of varying shades. This last while nearer the true Italian Siena than any now produced, differs in being distinctly granular in texture, and can perhaps be more correctly com- pared with the well-known Estremoz, or so-called Lisbon yellow from Alemtejo Province, Portugal. A fine grained black marble is also found in the near vicin- ity, which, while it does not polish well may answer for floor tiling. The Inyo marbles are perhaps among the most promising the west has as yet produced. Chemically they are a very pure dolomite, close grained and compact, and equally well adapted for exterior and interior work. Their superior hardness will cause a greater expense in working than in the eastern or Ital- ian marbles, but whether these items will not be more than counterbalanced by cost of transportation the future only can decide. The quarries are on steep hillsides quite devoid of timber or soil, and cost of fuel necessitates the transportation of the rough blocks to Essex, Nevada, a distance of some miles, before they can be sawn. Chemical analysis made at the laboratories of the State Mining Bureau yielded 54.25$ carbonate of lime, 44.45$ car- bonate of magnesia, and but 0.60$ of iron and silica. Specific gravity 2.80, which is equal to a weight of 179^ pounds per cubic foot. Near Plymouth in Amador County there are said to be white and variegated marbles suitable for general building, but of too coarse a grain for decorative work. White marble occurs in the mountains near San Jacinto in San Diego County. Good stone is described* as occurring in San Bernardino County, near Slover Mountain. This last has * Eighth Annual Report State Mineralogist of California, 1888, p. 504. 88 'STONES FOR BUILDING AND DECORATION. been worked for the San Bernardino market. Massive arago- nite suitable for ornamental work also occurs here. It is de- scribed as most beautifully striped and banded in various colors. This and other of the so-called onyx and serpentinous marbles are more fully described elsewhere. Colorado. No marbles are as yet quarried in this State, but the National collections show a small piece of a black, white- veined breccia from Pitkin that might rival the imported " Portoro " from the Monte d'Arrna quarries in Italy, if occur- ring in sufficient abundance. Concerning the extent and char- acter of the formation the author knows nothing. In the marble yards of Denver the author was shown during the sum- mer of 1886 a fine chocolate-colored stone, somewhat resemb- ling the more uniform colors of Tennessee marble, which was stated to have been brought from near Fort Collins, in Laramie County, where it occurred in great quantities ; also a fair grade of white blue-veined marble from Gunnison County. A beau- tiful breccia marble is stated* to occur in abundance a few miles north of Boulder City. Prof. Newberry states f that on Yule Creek, a branch of Crystal River, in a series of massive gray Palaeozoic limestones there is a belt of white marble apparently superior in quality to anything found elsewhere in the United States. The mar- ble belt is stated as being about 100 feet in thickness, and not less than six miles in length. The prevailing colors are pure white or white slightly clouded with gray. On the east side of the belt some of the layers are of a very beautiful blue or dove color. " So far as can be judged from exposures, much of this deposit deserves to be classed as statuary marble, and some of it is apparently equal to that taken from the quarries at Carrara, Italy, or the Grecian Parian or Pentellic marbles." .* Biennial Report of State Geologists of Colorado, 1880, p. 33. f School of Mines Quarterly, vol. x. No. i, 1888, p. 71. STONES FOR BUILDING AND DECORATION. 89 Connecticut. In the northern part of Litchfield County, near the Massachusetts line, in the town of Canaan, East Canaan, and Falls Village, there occur massive beds of a coarsely crystalline white dolomite, which have in years past furnished valuable building marbles, though recently they have been but little worked. The stone is said to weather well and to be obtainable in large blocks eminently suited for building, but like the Lee (Mass.) dolomite it frequently contains crystals of white tremolite, which weather out on exposure. It is therefore not so well suited for finely finished or monumental work. The State-house at Hartford is the most important structure yet made from this material. As elsewhere noted it was at Marble Dale, in the town of Milford in this State, that marble quarrying was first systemat- ically undertaken in this country, and at one time (1830) not less than fifteen quarries were in active operation in the vicin- ity. So far as can be learned not a single one of these is now being worked. Delaware. No marbles are at present quarried in this State, but a coarse white dolomite is found near Hockessin, New Castle County. This, so far as can be judged from the single specimen examined, might be used for general building, though not well suited for ornamental work. Georgia. An important belt of marble is said to extend through the counties of Cherokee, Pickens, Gilmer, and Fannin in the northern part of this State, the material varying in color from pure white through blue and variegated varieties, some of which are remarkably beautiful. Variegated marbles also occur in the counties of Polk, Floyd, Whitfield, Catoosa, Chat- tooga, Gordon, Murray, Barton, and Walker ; chocolate-red varieties similar to the marbles of Tennessee are said to occur in abundance in Whitfield County, the bed in Red Clay Valley extending in uninterrupted continuity for 10 miles, and varying cp STONES FOR BUILDING AND DECORATION. from one-fourth to one-half a mile in width.* Of the beds above mentioned those in Pickens and Cherokee Counties are at present the most important and the only ones that have been worked to any extent, quarrying having quite recently been commenced here by various companies. These marbles are of uniform texture, but much coarser than the Vermont marble, which in other respects they resemble. They are soft, work readily, and acquire an excellent surface and polish. In color they vary from snow white and pink to black and white mottled. The pink variety is unique as well as beautiful, and there is at present nothing like it produced in other parts of the country, though in color it closely resembles the pink mar- ble from Cherokee and Macon Counties, North Carolina, to be noticed later. It is, however, coarser. Chemical tests show these stones to be nearly pure calcium carbonate, quite free from admixtures of other minerals. They can apparently be depended on to weather uniformly. Pres- sure tests made at the Watertown arsenal on six-inch cubes gave maximum results of 12,078 Ibs. per square inch. The ready working qualities of these stones, the fact that owing to the mildness of the climate the works can be in opera- tion at all seasons of the year, together with the remoteness of regions where similar marbles are produced, all point to a rapid development of an extensive quarrying industry in this part of the country. Idaho. Marble sufficient to supply the local demand for cemetery work is stated to be quarried at Spring Basin, Cassia County, in this State. Iowa. The calcareous rocks of Iowa are, as a rule, non- crystalline, dull in color, and with few qualities that render them desirable for ornamental purposes. But few of them are * Commonwealth of Georgia, p. 135. STONES FOR BUILDING AND DECORATION. 9 1 pure limestone, but nearly all contain more or less magnesia, iron, or clayey matter ; very many of them are true dolo- mites. Near Charles City, in Floyd County, on the banks of Cedar River, are extensive quarries in the Devonian (Hamilton) beds of magnesian limestones, certain strata of which furnish a coral marble at once unique and beautiful. The prevailing color of the stone is light drab, but the abundant fossils vary from yel- lowish to deep mahogany brown. These last, which belong to the class of corals called Stomatophora, are very abundant and of all sizes up to 18 inches in diameter. As seen on a pol- ished surface imbedded in the fine, drab, non-crystalline paste of the groundmass, they present an appearance totally unlike anything quarried elsewhere in America an appearance at once grotesque and wonderfully beautiful. The stone admits of a high polish, and would seem excellently adapted for all manner of interior decorations, if obtainable in blocks suffi- ciently uniform in texture. A small amount of argillaceous matter and scattering particles of amorphous pyrite, which are occasionally visible, render its adaptability to outdoor work decidedly doubtful. The stone is known commercially as Madrepore marble. A polished slab 2 by 4 feet is in the collections of the National Museum. The light yellowish, buff, or brown sub-Carboniferous mag- nesian limestone, quarried near Le Grand in Marshall County, also contains massive layers beautifully veined with iron oxide, and which are suitable for ornamental purposes, though it is not considered suitable for monuments and other work subject to continuous exposure. I have not seen samples of this ma- terial, though it is well spoken of by White.* It is popularly known as Iowa marble. The only other stone which, so far * Geology of Iowa, vol. u. p. 313. 92 STONES FOR BUILDING AND DECORATION. as I am aware, has ever been utilized for ornamental purposes is the so-called " Iowa City," or " Bird's-eye marble." This is nothing more than fossil coral " (Acervularia Davidsoni) imbed- ded in the common Devonian limestone and often perfectly consolidated by carbonate of lime so that it may be polished like ordinary marble. When so polished its appearance is very beautiful, for the whole internal structure of the coral is as well shown as it is in living specimens, and yet it is hard and com- pact as real marble." The stone would be valuable could it be obtained in blocks of large size. Unfortunately it occurs in pieces of but a few pounds' weight ; it is used therefore only for paper-weights, and small ornaments of various kinds. Maryland. The principal marble quarries of this State are located near Cockeysville and Texas, some 16 miles north of Baltimore, on the Northern Central Railroad. Here there occurs a small and isolated area of Lower Silurian (?) dolo- mite of medium texture and white color that has been very extensively used for general building purposes in Baltimore, Washington, and the neighboring towns, and to a less ex- tent in Philadelphia. In the quarries the stone lies in large horizontal masses, and blocks 28 by 10 by 3 feet have been quarried entire. This stone was used in the construction of Christ Church in Baltimore, the Washington Monument and the columns and heavy platforms of the Capitol extensions at Washington, D. C. Near Union Bridge, in Frederick County, there occurs a fine-grained and compact white magnesian limestone, but which has not been quarried to any extent. The only true conglomerate or breccia marble that has ever been utilized to any extent in the United States is found near Point of Rocks, Frederick County, in this State. The rock, which belongs geologically to the Triassic formations, is composed of rounded and angular fragments of all sizes, up to STONES FOR BUILDING AND DECORATION. 93 several inches in diameter, of quartz and magnesian limestone imbedded in a fine gray calcareous groundmass. This com- position renders the proper dressing of the stone a matter of some difficulty, since the hard quartz pebbles break away from the softer parts in which they lie, leaving numerous cavities to be filled with colored wax or shellac. It should therefore never be worked with hammer and chisel, but only with saw and grinding material, and no attempt made at other than plain surfaces. The stone was used for the pillars in the old Hall of Representatives in the Capitol at Washington, and a polished slab 34 inches long by 20 inches wide, may be seen in the National Museum at Washington. The pebbles forming the stone are of so varied shades that to state its exact color is a matter of difficulty. Red, white, and slate-gray are perhaps the prevailing tints. On account of its locality this stone has been popularly called " Potomac " marble, or sometimes calico marble, in reference to its structure and spotted ap- pearance. The formation from whence it is derived is said to commence near the mouth of the Monocacy River, and to ex- tend along the Potomac to Point of Rocks, and along the valley on the eastern side of the Catoctin Mountain to within 2 miles of Frederick. The writer is informed, moreover, that the same formation occurs in Virginia, near Leesburgh, and that here the quartzose pebbles are almost entirely lacking, thereby rendering the stone much less difficult to work. Massachusetts. Crystalline limestones and dolomites of such a character as to assume the name of marble are now or have been in times past quarried in various towns of Berkshire County, in this State. The stones are all white or some shade of gray color, medium fine-grained in texture, and are better adapted for general building than for any form of ornamental work. The quarries at Lee were opened in 1852, and the stone has 94 STONES FOR BUILDING AND DECORATION. been used in the Capitol extension at Washington and the new city buildings in Philadelphia ; but little of it has been used for monuments. In the quarries the stone lies very massive, and it is stated cubes 20 feet in diameter could be obtained if necessary. The Sheffield quarries were opened about 1838. The rock here is massive, with but little jointing. Natural blocks 40 feet square, and 3 feet in thickness can be obtained. The Alford stone is used mostly for monumental work, and ap- pears very durable. Much of the marble from these localities contains small crystals of white tremolite which weather out on exposure, leaving the rock with a rough pitted surface. This is very noticeable in the exterior walls of the Capitol building at Washington, already noted. Missouri. The writer has seen but few true marbles from this State, though colored marbles of fine quality equalling the variegated varieties of Tennessee are reported by Professor Broadhead as occurring in Iron, Madison, and Cape Girardeau Counties. The Iron County stone is reported as light drab in color, with buff veins. The outcrop occupies an exposure of several hundred feet of a low bluff on Marble Creek near the east line adjoining Madison County. The Madison County marble occurs near Fredericktown, and is described as the best- appearing marble in the State, both in regard to color and tex- ture, the colors being red, peach-blossom, and greenish, beauti- fully blended. The stone is represented as very durable, but liable to tarnish on a polished surface when exposed to the weather. The Cape Girardeau stone is represented as of a variety of colors purple, yellow, red, pink, gray, and greenish all being enumerated ; the supply is unlimited. None of these marbles are at present systematically worked, owing to lack of capital and distance from market. Professor Broadhead further states that few of the marble beds of southeastern Missouri are STONES FOR BUILDING AND DECORATION. 95 thick enough to be economically worked, as there would be too large a portion of waste material. No pure white crystalline marbles are as yet known to occur within the State limits. Other stones capable of receiv- ing a polish and suitable for marble are stated to occur in the counties of Saint Louis, Saint Charles, Warren, Montgomery, Rails, Galloway, Lincoln, Cooper, Pettis, Cass, Jackson, Living- ston, and Clay.* Montana. This State as yet quarries no marble of import- ance. There were exhibited, however, at the Centennial, in Philadelphia, 1876, and since then in the National Museum at Washington, two samples from Lewis and Clarke County that are worthy of note, since they form the nearest approach to the imported Italian black and gold marble from the Spezzia quar- ries of any at present found in America. The rock is very close and compact, of a dark blue-gray color, and traversed by irregular wavy bands of varying width of a dull chrome-yellow color. So far as observed the stone is far inferior in point of beauty to its Italian prototype, and apparently would prove more difficult to work. Nevada. Practically no attempts have as yet been made toward working the marble deposits of this state, and indeed very little is known regarding their extent and qualities. Prof. Newberryf states that in the Tempiute Mountains, in the southeastern part of the State, there are beds of limestone of a great variety of colors and textures, susceptible of a high polish and scarcely inferior in point of beauty to any marble imported from the old world. New Jersey. At one time extensive marble quarries were worked in the outcrops of Devonian limestone at Lower Har- * See also Bulletin No. I, Missouri Geological Survey, 1890. f School of Mines Quarterly, No. i, vol. x. 1888, p. 70. 96 STONES FOR BUILDING AND DECORATION. mony in Warren County. The stone is of a grayish hue, in places banded owing to alternate lines of light and dark miner- als. Nodules of hornblende and steatite are scattered through the rock, and rarely there is pyrite and some graphite. The stone was worked mainly for the Pennsylvania market. A very beautiful stone known commercially as the " Rose Crystal Marble" has been quarried on a subordinate ridge of the Jenny Jump Mountain range in this county, at the corner of the Hope and Danville road, and the road running north- ward along the Great Meadows. The stone consists mainly of large white, flesh pink, and rose colored crystals of calcite interspersed with black mica, a green pyroxene and occasional black tourmalines. Its texture is such that it must be handled with some care, but it polishes well and makes a beautiful ornamental stone for interior work. It is said to have been obtainable in blocks 8x3x2 feet without seams or flaws.* The fact that the quarries were situated seven miles from the nearest railroad may account in part for its being no longer worked, but it is a great pity that so beautiful a stone should not be utilized. New York. The belts of Archaean dolomite which lie to the north of New York City and cross the State in a northeasterly direction furnish a very fair quality of white and gray marbles that have at various times been quiet extensively utilized. Of these belts, one reaches New York Island, crossing the Har- lem River at Kings' Bridge ; another outcrops on the Sound near New Rochelle ; others still strike the Hudson above New York, at Hastings, Dobbs Ferry, Sing Sing, etc. Several of these beds furnish good marbles for building stone, gray, blue, or white, but none that is fine for decorative purposes. The best marbles yet obtained from the series of deposits are those of * Annual Report State Geologist of New Jersey, 1872. STONES FOR BUILDING AND DECORATION. 97 Tuckahoe and Pleasantville in Westchester County. The Tuckahoe marble is pure white in color, and coarser than those of New England in general, notice elsewhere. It is somewhat irregular in quality, but the better grades are highly esteemed for architectural purposes, and have been used in some of the finest buildings in New York City. By exposure to the impure atmosphere of the city, its color changes to a light gray. This is apparently due to its coarseness of texture, which gives a roughness to the surface, and causes the smoke and dust to ad- here to it more closely than they would to a finer stone. The dolomite belt in which the Pleasantville marble quar- ries are situated is one of the broadest known, being more than half a mile wide. It consists chiefly of beds of impure dolo- mite, white or banded, which contain too much siliceous matter to be available for building or ornamental purposes, with some layers, often of a considerable thickness, of pure white marble, in part similar to that of Tuckahoe, and partly still more coarse- ly crystalline. These beds are more or less interstratified with layers of granite or gneiss, the whole series standing nearly on edge. The belt which furnishes the snowflake marble is about one hundred feet wide, standing vertical, and consists through- out of pure white dolomite, almost without cloud or stain, and with no foreign matter.* On account of its coarseness this stone is not well adapted for carved work or for use in long columns. The Tuckahoe stone is not quite so coarse in texture and has been more exten- sively employed for building purposes. At Sing Sing and Do- ver Plains are other quarries of rather coarse white dolomite marble, but which are not extensively worked. A very coarsely crystalline light-gray magnesian limestone of Archaean age occurs at Gouverneur, in St. Lawrence County. * Newberry, Report of Judges, vol. HI. International Exposition, 1876. 98 STOA T ES FOR BUILDING AND DECORATION. Although too coarse for carved work it answers well for mas- sive structures, and, as it acquires a good surface and polish, is used largely for monuments as well as for building and for or- namental work. It is believed to be durable, since gravestones in the vicinity which have been set upwards of seventy years still present clean and uniform surfaces, and are free from lichens and discolorations of any kind. Two excellent varieties of colored marbles occur in the Lower Silurian formation at Plattsburgh and Chazy, in Clinton County, in this State, and which are commercially known as " Lepanto " * and French gray. The first consists of a close fine-grained gray groundmass with pink and white fossil re- mains, which are evidently crinoidal. The second is more uni- formly gray and bears larger fossils. It is an excellent stone, and, with perhaps the exception of those of Tennessee, has been used more extensively for mantels, table tops, tiling, and general interior decorative work than any other of our marbles. At Glens Falls, on the Hudson River, occurs an extensive deposit of dark blue-black magnesian limestone, certain strata of which furnish the finest varieties of black marble at present quarried in this country. The stone is very fine-grained and compact, and, when polished, of a deep, lustrous black color, though the uniformity of the surface is sometimes broken by the presence of a small white fossil. A two-foot cube of this stone is in the National collections. The finest quality of this marble occurs in a single stratum some 12 feet in thickness. The poorer qualities are burned for lime, of which they furnish material of exceptional purity. Black marble is also quarried to some extent at Willsborough, in Essex County. At Port Henry, in this same county, there is quarried a green and * The Lepanto marble is figured in PI. xxxn. of the Census Report, where it is wrongly set down as from Isle La Motte, Vermont. STONES FOR BUILDING AND DECORATION. 99 white speckled marbled, composed of an intimate mixture of serpentine, calcite, and dolomite that has been used for interior decorative work. The stone has been noticed more fully under the head of serpentine. At Lockport there is extensively quarried a soft gray crinoi- dal Upper Silurian limestone in which the fossils are frequently of a pink or bluish opalescent color. It is used to some extent for mantels and other ornamental purposes.* In the town of Warwick, in Orange County, there is found a beautiful, coarsely crystalline marble of a carmine-red color, sometimes slightly mottled or veined with white. But little of it has been used and the supply is reported as small. North Carolina. Although no quarries of marble are at the present time worked to any extent in this State, there occur within its limits numerous deposits of most excellent material that only require enterprise and capital to bring to a ready market. One of the most important of these is near Red Marble Gap, in Macon County. The rock is a beautiful bright flesh pink, sometimes blotched or striped with blue and yellow. The texture is fine and even, and it acquires an excellent sur- face and polish. The stone is stated by Professor Kerr to occur in the side of the mountain in cliffs 150 feet or more in height, and blocks of almost any size can be obtained. It is quite different from anything now in the market, and would doubtless find a ready sale if once introduced. Other marbles of white or blue-gray color occur in Murphy, and Valley Town, Cherokee County ; Warren Springs, Madison County, and near Marion, in McDowell County. Lack of transportation facili- ties at present is a serious drawback to the introduction of any of these into our principal markets. I have seen, also, small * J. S. Newberry in report on building and ornamental stones, vol. ill. Internationa] Exhibition Reports, p. 158. IOO STOA'ES FOR BUILDING AND DECORATION, pieces of very compact deep blue-black crystalline limestone, taking a high polish and suitable for the finest grades of ornamental work from near Nantehaleh, Swain County, in this State. Portions of the stone are traversed by a coarse net- work of pure white calcite veins that greatly add to its beauty. Pennsylvania. The belt of Lower Silurian limestone that extends from Sadsbury and Bart Townships, in Lancaster County, in a general easterly direction through Chester Coun- ty, and through the western half of Montgomery County, in- cludes within its area the only quarries of merchantable marble at present worked within the State limits. According to Pro- fessor Rogers'* this belt forms the bed of a narrow valley some 58 miles in total length, extending from near Abington, in Montgomery County, to the source of Big Beaver Creek, in Lancaster County. The prevailing colors of the stone through- out the larger portion of this area are yellowish or bluish, and it is, as a consequence, suitable only for making quicklime or for ordinary rough building purposes. On the southern side of the valley, however, between Brandywine and Wissahickon Creeks, the stone has become highly metamorphosed and con- verted into a crystalline granular marble, white or some shade of blue in color, though often variously veined or mottled. All the quarries as yet opened are situated in Montgomery County, on the steeply upturned or overturned edges of the outcrops within half a mile of the southern edge of the formation be- tween Marble Hall and the Chester County line. It is stated that quarries were first opened here about the time of the Revolutionary war, and that up to 1840 this stone was the favorite and almost only material used in the better class of stone buildings in and about Philadelphia. At about the latter date increased facilities for transportation brought * Report of First Geological Survey of Pennasylvania, vol. I. p 211. STONES FOR BUILDING AND DECORATION. IOI the better varieties of eastern marbles and other stones into competition with it and its use has as a consequence consider- ably diminished. Among the important buildings constructed of the stone during its popularity were the United States Cus- tom-house and Mint, the Naval Asylum and Girard College, while the seemingly endless rows of red brick houses with white marble steps, door and window trimmings, are even now as characteristic of Philadelphia as are the brown-stone fronts of New York City. The sarcophagi for General and Martha Washington, at Mount Vernon, are also of this material. While the Montgomery County stone has shown itself to be very durable, in point of beauty it falls far short of the marbles from the more Eastern States, and hence its use for any form of ornamental work has almost entirely ceased. There were, however, on exhibition at the Philadelphia Ex- position of 1876 (and since then transferred to the National Museum) samples of this limestone from along the Lebanon Branch of the Philadelphia and Reading Railroad, some of which gave promise of great utility. I would mention especi- ally two samples from Myerstown and Mill Lane. These are very fine-grained and compact, of a drab or bluish color on a polished surface, and traversed by wavy and very irregularly anastomosing, nearly black lines. They seem in every way admirably adapted for decorative work, though I am not aware that they have as yet been at all used for this purpose. Newberry states* that a fine variety of black marble occurs in or near Williamsport, Lycoming County. I have never seen the stone and know nothing further regarding it. A black limestone that takes a fine polish and> appears well suited for interior work is stated also to occur near the east end of Mosquito Valley, in the same county. For exterior work it is stated to be unsuited, as it splinters up badly on exposure. * Op. cit. pp. 138, 139. IO2 STONES FOR BUILDING AND DECORATION. Tennessee. The valley of East Tennessee is underlaid by limestone of Lower Silurian age that furnishes some of the finest and most beautiful grades of colored marbles at present quarried in the United States. At the present time the most extensive quarries are situ- ated in Knox and Hawkins Counties. The prevailing colors found here are chocolate red and white, often coarsely varie- gated and fossiliferous, though finely and evenly crystalline varieties of a beautiful pink or strawberry color, with scarce- ly a trace of fossil remains, also occur. All of them cut to a sharp edge and acquire a beautiful and lasting polish not ex- celled and rarely equalled by any foreign or domestic marbles. Of foreign marbles, so far as the writer is aware, they have no exact counterpart, but perhaps resemble the Rosso de Levan- to from Spezia, or the Persian fiorto, more closely than any other that can be mentioned. Besides the localities above mentioned, colored marbles occur in the following counties in this part of the State : Han- cock, Grainger, Jefferson, Roane, Blount, Monroe, McMinn, and Bradley ; some also occur in Meigs, Anderson, Union, and Campbell Counties. The Hawkins County marble is part of a comparatively short belt of Trenton and Nashville rocks lying west of Rogersville. It is some 16 or 17 miles long, and from 50 to 300 feet in thickness. The supply is therefore practically unlimited and inexhaustible. The best variety of the stone is used only for ornamental work, owing to its high price, being valued at from $2 to $3 per cubic foot delivered at the nearest railway station. The Knox County qyarries are mostly situated within a few miles of the city of Knoxville. According to Dr. Safford the entire thickness of the marble bed here is some 300 feet, the different layers of which vary from chocolate red and white variegated varieties through grayish white, pinkish, and more STONES FOR BUILDING AND DECORATION. 1 03 rarely greenish colors. The most esteemed variety has when polished, a brownish red color, with white spots and clouds, due to fossil corals and crinoids. The grayish white variety, which is the nearest approach to a truly white marble of any now found in the State, is greatly esteemed for tombstones, monu- ments, tiling, etc., and is said to be very durable, tombstones which have been exposed for upward of thirty years showing no signs of disintegration or wear. Both the Hawkins County and Knox County stones are very strong and heavy, weighing about 1 80 pounds per cubic foot, which is some 14 pounds heavier than granite. Quite similar variegated marbles are said to occur in many of the counties of the Cumberland table- land, as in Franklin County, on the Elk River and at the Oil Springs, on Leipor's Creek, in '>ury County. Some of the marbles of this latter place have a grayish groundmass, with fleecy clouds of red and green.* A beautiful olive-green fossiliferous marble is also found in the eleventh district of Davidson County, though the extent of the deposit is not known by the writer. Near Calhoun, in McMinn County, just south of the Chilhowee Mountain, occur breccia marbles of exceptional beauty, of pink and olive green colors. One quite unique stone from this locality is composed of a grayish-ground mass, with large rounded and angular frag- ments of a lemon-yellow color. These same marbles also occur in Greene, Cocke, Sevier, and all counties of the Unaka range, but they are not much worked, on account of the hardness of the included fragments.f Dove-colored marbles are stated by the same authority to occur a few miles south of Manchester, Coffee County, and in * Tennessee and its Agricultural and Mineral Wealth, by J. B. Killebrew, page 149. f Geology of Tennessee, p. 221. IO4 STONES FOR BUILDING AND DECORATION. Wilson and Davidson Counties. Dark limestones, almost black when polished, and often traversed by veins of calcite, forming a good black marble, are not uncommon. Such occur in the vicinity of Jonesborough, Washington County; at Greeneville and Newport, Cocke County ; on the Pigeons, in Sevier County; and also in McMinn and Polk Counties. They are at present but little used. Colored marbles are also said to occur in the Western Tennessee Valley. These, though somewhat inferior in point of beauty to those of the East Valley, are still valuable stones. Perry, Decatur, Wayne, and Hardin Counties are mentioned as offering the best facilities. On Shoal Creek, in Lawrence County, are said to be beds of fawn-colored or brownish-red marbles, some 40 feet in thickness and extending on both sides of the creek for a distance of fifteen miles. The stone is often variegated by fleecy clouds of green or red, green and white colors. Owing to lack of transportation facilities it is not now in the market. In W r ilson and Davidson Counties other beds of bluish or dove-colored marble occur, and in Rutherford County is a bed of pale yellow marble with serpentine veins of red and black dots. The extent of the deposit is not known, and at present the stone is seen only in the form of small ob- jects for paper-weights and curiosities. Texas. The resources of this State are as yet but little known. There are on exhibition in the National Museum at Washington several samples of compact, light-colored Creta- ceous limestones, from the vicinity of Austin, Travis County, a few of which are of such quality as to be used as marbles. There was on exhibition at the New Orleans Exposition in 1884-85 a marble fire-place and mantel of Austin marble that was worthy of more than passing notice. The stone was com- pact, very light drab in color, and interspersed with large fossil shells and transparent calcite crystal. This composition would TJ1TI7BRSIT7 PLATE IV. LA rat fe M MVi THE MARBLE REGION OF WESTERN NEW ENGLAND. [The marble is indicated as limestone on the map.] To face /xige 105. STONES FOR BUILDING AND DECORATION. IO5 render some care necessary in cutting, but the final result would seem to justify the outlay. Other marbles from Burnet and vicinity present a variety of colors, some of which are very pleasing. They range from blue-gray and distinctly crystalline to very fine and compact forms, designated as " mahogany- red," " red and white," " purple variegated," etc. The ma- hogany-red is dull in color, and traversed by a net-work of lighter lines. It is too hard and brittle to work economic- ally. The most promising variety is the purple variegated. This presents an extremely compact base of a grayish, or light lavender-tint, which is traversed by fine, irregular lines of a red and purple color. The stone acquires an excellent surface and polish, but is so hard as to work with great difficulty. Utah. A yellowish white crystalline limestone, that can scarcely be called a marble, occurs near Payson, in this Terri- tory, and a compact nearly black stone, interspersed with nu- merous white fossil shells, in the San Pete Valley. Neither stone can lay any claim to beauty, though possibly the last mentioned might be made to do as marble under certain cir- cumstances. Vermont. Since this is the leading marble-producing State of the Union a brief description of the chief geological features of the marble formations may not be out of place here. Ac- cording to Professor Brainard* this formation extends along the western borders of the States of Connecticut, Massachu- setts, and Vermont, between the Green Mountain elevation, which extends from the Canada line nearly to Long Island Sound, and the intermittent Taconic Mountains, which extend south of Lake Champlain, and in places admit the marble veins within the border of New York. Of these immense for- * The Marble Border of Western New England, p. 9. IO6 STONES FOR BUILDING AND DECORATION. mations, which are from 1,000 to 2,000 feet in thickness, the lower portion, known to geologists as the Calciferous (300 to 400 feet in thickness), is for the most part siliceous, partaking of the nature of the sandrock that underlies it. The upper portion, known as the Trenton (500 to 600 feet in thickness), is impure from the presence of clayey matter, partaking of the nature of the slate formation that overlies it. Only certain layers of the middle portions seem to have been fitted by their original constitution for the production of marble. The limits of the formation may be best understood by reference to the accompanying map (Plate iv), redrawn from Professor Brainard's report.* Professor Hitchcockf conveniently divides the marbles of this Sate into four groups or classes: (i) the common white and bluish or Eolian marble, so called from its occurring extensively on Mount Eolus ; (2) the Winooski ; (3) the varie- gated of Plymouth, and (4) the dark, almost black, of Isle La Motte. We will consider these in the order here given. The beds of the Eolian variety as described by Prof. Hitch- cock are not restricted to one locality, but are distributed over a large portion of western Vermont, the formation in which it occurs extending the entire length of the State, and usually interstratified with siliceous and magnesian limestones. The strata vary in thickness from a few inches to 6 or 8 feet, the thickest beds being usually found where the marble is coarse- grained and friable. In texture this variety of the stone is as a rule fine-grained, and often saccharoidal, though less so than the Italian marbles. In color it varies from pure snowy white through all shades of bluish, and sometimes greenish, often beautifully mottled and * By permission of the Middlebury Historical Society, f Geology of Vermont, vol. u. p. 752. STONES FOR BUILDING AND DECORATION. 1 07 veined, to deep blue black, the bluish and dark varieties being as a rule the finest and most durable. Many quarries have first and last been opened along this belt, and the industry has added materially to the prosperity of the towns here situated. Among those towns in which the quarry industry has been par- ticularly active maybe mentioned (beginning with the southern- most), Dorset, and East Dorset, Wallingford, West Rutland, Sutherland Falls (Proctor), Pittsford, Brandon, and Middlebury. As a rule the best marbles are said to occur where the beds or strata stand at a high angle, as at West Rutland. The quarries in Dorset are mostly situated upon the sides of Mount Eolus, or Dorset Mountain, as it is also called, a sec- tion of which, after Hitchcock, is here given. The thickness of the slaty cap rock is estimated at 498 feet, and the various beds of limestone below at 1,970 feet. Although but a small portion of this is suitable for quarry- ing, still the supply is readily seen to be inexhaustible. The prevailing colors of the stone, as at Rutland, are white and bluish, vari- ously mottled and veined. According to Professor Seely, the first quarry opened in Dorset was by Isaac Underbill, in 1785, the stone being used chiefly for fire-jambs, chimney-backs, etc. The first marble grave-stones ever furnished here were the work of Jonas Stewart, in 1790. From Dorset the beds thin out toward the north, the more northerly beds, though thinner, usually furnishing the finer grained and more compact stone. The marble strata in Rutland and Addison Counties appear in two parallel lines about 2 miles apart, stretching from the north line of Middlebury to the south line of Rutland, and are from 100 to 200 feet in thickness. These strata are not how- IO8 S7VNES FOR BUILDING AND DECORATION. ever homogeneous throughout, but as seen in the quarry open- ings the stone occurs in beds usually but a few feet in thickness which vary considerably in color, so that several grades, from pure white through greenish, bluish, and almost black, may be taken from the same quarry. Professor Hitchcock gives the following figures relative to the marble-beds at one of the West Rutland quarries, begin- ning at the eastern side or top layer : 1. Upper blue layer, 4 feet thick. 2. Upper white layer, 3 feet 6 inches thick. 3. Gray limestone layer, 5 feet thick. 4. White statuary layer, 3 feet thick. 5. Striped layer, I foot 8 inches thick. 6. New white layer, 4 feet thick. 7. Wedged white layer, from 8 inches 2 feet 6 inches thick. 8. Muddy layer, 4 feet thick. 9. Striped green layer, 4 feet thick. 10. Camphor-gum layer, 3 feet thick, n. White layer, 9 feet thick. 12. Blue layer, 3 feet 6 inches. The quarries themselves at this village lie along the western base of a low range of hills, which, to the ordinary observer, give no sign of the vast wealth of material concealed beneath their gray and uninteresting exteriors. In quarrying, the best beds are selected, and upon their upturned edges excavation is commenced, first by blasting, to remove the weathered and worthless material, and afterward by channeling, drilling, and wedging ; no powder being used lest the fine massive blocks become shattered and unfit for use. The quarry thus descends in the form of a rectangular pit, with almost perpendicular, often overhanging, walls, to a depth of sometimes more than 200 feet, when the beds are found to curve to the eastward and pass under the hill, becoming thus more nearly horizontal ; in following these the quarry assumes the appearance of a vast cavern from whose smoke-blackened, gaping mouths one would little suppose could be drawn the huge blocks of snow-white material lying in gigantic piles in the near vicinity (see Plates I and v). Some of the quarries have been partially roofed over to protect them from snow and rain, and seem like mines A '. v\\ i\ A f *i,t. V a w 4 M UNIVERSITY **- STONES FOX BUILDING AND DECORATION. IOQ rather than quarries. The scant daylight at the bottom is scarce sufficient to guide the quarryman in his work. As one peers cautiously over the edge into the black and seemingly bottomless abyss, naught but darkness and ascending smoke and steam are visible, while his astonished ears are filled with such an unearthly clamor of quarrying machines, the puffing of engines, and the shouts of laborers, as is comparable with nothing within the range of our limited experience, and the reader is at liberty to make his own comparisons. The stone taken from the quarries is worked up in the companies' shops in the immediate vicinity or shipped in the rough as occasion demands. The supply is used for monu- mental, decorative, or statuary work and general building. At Sutherland Falls the stone is very massive, and large blocks are taken out for building purposes. Some of the most valuable marbles, according to Professor Seely, are here known as the dark and light mourning vein varieties. The dark mourn- ing vein has a ground of deep blue, while lines, nearly black, run through it in a zigzag course, presenting a beautiful ap- pearance. The light mourning vein has similar veins, but the ground is lighter. T! e quarries at this place are described by Professor Seely as being in the form of a hollow cube cut into a hill, with perpendicular walls on the north and west rising to a height of nearly 100 feet, open to the sky, and with an acre of rock forming its horizontal marble floor. Over this floor are run channeling machines, cutting out long parallel blocks which are afterwards cut up into convenient size, lifted from their beds, and taken to the mills to be sawn. It is stated * that Pittsford has the honor of having one of the earliest quarries in the State, if not the earliest, Jeremiah Sheldon having worked marble here as early as 1795. There * The Marble Border of Western New England, p. 46. IIO STONES FOR BUILDING AND DECORATION. are three beds of marble running through the town, north and south. The most easterly has a breadth of some 200 feet, and the stone is of the same character as that at Sutherland Falls or Proctor, as the town is now called. The middle bed is sepa- rated from the first by about 200 feet of lime rock. The bed itself is some 400 feet wide, and the stone varies in color from pure white to dark blue. The third or west bed which is thought to correspond to that of West Rutland is about half a mile west of the central and is about 400 feet wide. The stone is dark-blue and often beautifully mottled. Some of the beds here, as at West Rutland, furnish a beautiful snow-white saccharoidal stone suitable for statuary purposes, for which it has been used to a slight extent. The Vermont statuary mar- ble, however, differs from its Italian prototype, in being of a dead white color and lacking the mellow, waxy lustre so char- acteristic of the Italian stone. Several outcrops of marble occur in Middlebury, and which have been worked for many years past ; but in consequence of the thinness of the beds, their badly jointed structure, and the interstratification of a magnesian slate that produces numerous " rising seams/' it is said to be quite difficult to obtain per- fectly sound blocks of large size. Nevertheless much valuable material has been taken out here, both for architectural and monumental work. The bed of primordial rock known to geologists as the " red sand-rock," which occurs in the northwestern part of the State, bordering on Lake Champlain, is, as a rule, a hard, dark- red sandstone, containing some 8 or 9 per cent of potash, with about the same amounts of iron and lime. The entire forma- tion, which is some 2,000 feet in thickness, is, however, by no means uniform in composition, but includes considerable beds of limestone, dolomite, slate, and shale. It is the dolomitic layer which furnishes the peculiar red-and-white mottled stone STONES FOR BUILDING AND DECORATION. Ill popularly known as Winooski marble. According to a writer in the American Naturalist,* the beds of this marble appear first one or two miles north of Burlington, and extend in a somewhat interrupted series north through St. Albans, and end between that place and Swanton. More than thirty years ago a quarry was opened in this rock about 6 miles from Bur- lington, but owing to the hardness of the stone the enterprise proved a failure and the quarries were abandoned. Later, quarries were opened at St. Albans, and still more recently were re-opened at Burlington, the stone being used largely for flooring-tiles, wainscotings, and general interior decorative work. Asa rule the stone is crystalline and very hard, much harder than ordinary marble. Its color is quite variable, though some shade of red mottled with white usually predominates. Some varieties are beautifully light pink and white, or pink and deep blue-gray or greenish. The very common chocolate-red and white variety is put upon the market as Lyonaise marble, and is used largely for tiling, its natural color being often rendered darker by oiling. Chemically the ^tone is a dolomite, though varying widely in composition in samples from different localities. Some samples show a very decided brecciated structure, while in others this entirely disappears. It is, as a rule, very hard to work, and, as exhibited in the capitol building at Albany, New York, the surface is often disfigured by irregular cavities and flaws which are rather unsightly. The color is said to fade on exposure to the weather, and hence the stone is used mostly for interior work. An excellent outcrop of this marble occurs on the shore of Mallet's Bay, in the town of Colchester. The strata at this point are nearly horizontal, and in many places form the banks * George H. Perkins, American Naturalist, Feb. 1881. 112 STONES FOR BUILDING AND DECORATION. of the lake. One of the quarries is so situated that a vessel can be brought up alongside and loaded with blocks with as much ease as they are usually loaded upon carts or cars at in- land quarries. The stone occurs in beds varying in thickness from i to 6 feet, and blocks of almost any size can be obtained. It is hard to work, but as a consequence is very durable when once finished, being not easily scratched or scarred. The best developments of the rock for marble quarrying are at Colchester, as already mentioned, Milton, Georgia, Saint Albans, and Swanton. At the last-named place there also occurs a beautiful gray marble, with angular fossil fragments of a white and pink color, identical with the " Lepanto " mar- ble of New York. There is also a fine and compact dove-col- ored marble here, admirably adapted for decorative work, but the quarries are now abandoned. The Plymouth marble, so called, is a quite pure dolomite, an analysis by Dr. Hunt resulting as follows : Per cent. Carbonate of lime , 53.9 Carbonate of magnesia 44. 7 Oxides of iron and alumina. 1.3 99-9 The stone occurs in the talcose schist formation near the centre of the town of Plymouth, at an elevation of 250 feet above the Plymouth pond. Quarries were opened here about 1835, but were soon abandoned, as the demand at that time was almost altogether for white marble. The beds dip 60 to the east, and the quarry walls, which have been exposed to the weather for twenty years, seem unaffected. In color the stone is blue or bluish-brown, diversified with long stripes and figures STONES FOR BUILDING AND DECORATION. 113 of various shapes in white. It is fine grained and compact, splitting with equal facility in every direction.* The Isle La Motte marble derives its name from Isle La Motte, in Lake Champlain, where it occurs in considerable abundance. It also occurs on several other islands in this lake and upon its banks in many places. According to Professor Hitchcock this was the first marble worked in the State, quar- ries having been opened prior to the Revolutionary war. The stone, which is largely used for flooring-tiles, is very dark, almost black in color, and highly fossiliferous, having under- gone less metamorphism than the marble in the interior of the State. So far as the author has observed, its color and texture are such as to preclude its obtaining a high rank for purely decorative purposes, but for floor-tiling is much esteemed and very durable. Fossil shells of great beauty are not uncom- mon, and, being snowy white in color, show up in strong con- trast to the dark paste in which they are embedded. Virginia. The extensive area comprehended under the title of the Valley of Virginia embraces " all the portion of the State having for its eastern boundary the western slope of the Blue Ridge and its inflected continuation the Poplar Camp and Iron Mountains, and for its western the Little North and a portion of the Big North Mountain, with the southern pro- longation of the former, Caldwell and Brushy Mountains; and near its southwestern termination the line of knobs forming the extension of Walker's Mountain."f The central portion of the valley as thus outlined is under- laid largely by limestones of Silurio-Cambrian age, which are in several places, according to the authority above quoted, capable of yielding good marbles. The special varieties men- * Geology of Vermont, vol. n. p. 776. f Rogers, Geology of the Virginias, pp. 203,204. 114 SJ^ONES FOR BUILDING AND DECORATION. tioned are: (i) a dun-colored marble met with near New Mar- ket and Woodstock, and on the opposite side of the Massan- utten Mountain in Page County; (2) a mottled bluish marble to the west of New Market ; (3) a gray marble occurring some three-fourths of a mile in a southeasterly direction from Bu- chanan, in Botetourt County ; (4) a white marble of exquisite color and fine grain about 5 miles from Lexington, in Rock- bridge County ; (5) a red marble occurring only in the Cam- brian formations lying among the mountains in the more southwestern counties ; and (6) a shaded marble found in Rockingham County. This last is said to be compact, suscept- ible of a beautiful polish, and of a yellowish gray and slate color. None of the above have as yet received more than a local application. At Craigsville, in Augusta County, there occurs a gray, sometimes pink-spotted encrinal limestone which acquires a good polish, and though in no way remarkable for its beauty is capable of extensive application for furniture and interior de- coration. The Archaean area to the eastward of the Valley of Virginia also includes sundry areas of workable marble. It is stated by Rogers that " near the mouth of the Tye River (in Nelson County) and the Rockfish, a true marble is found, of a beautiful whiteness and of a texture which renders it suscept- ible of a fine polish as well as being readily wrought with the chisel. A few miles from Lynchburg, in Campbell County, a good marble is likewise found." " The Tye River marble and one or more analogous veins " are further stated to " have all the characters of a statuary marble of fine quality, and should not some peculiarity, as yet unperceived, prevent their appli- cation for the purposes of the sculptor, they will no doubt be looked upon as very valuable possessions." The writer has seen none of the material from this locality. White and pink marbles of excellent quality also occur in the vicinity of Goose STONES FOR BUILDING AND DECORATION. 115 Creek, in Loudoun County. I have seen samples of the white, which for purity of color, fineness of grain, and general excel- lence, are not excelled by any marble now quarried in the United States, but the extent of the deposit is as yet unknown. These same beds also produce a green or verdantique marble of great beauty. The stone is an impure magnesian limestone admixed with a large amount of serpentinous mat- ter. The prevailing hue is green, but the stone is streaked and blotched in various shades and often brecciated. It is well adapted for interior work, but the presence of abundant pyrite renders it unfit for exterior application. The stalagmitic deposits upon the floors of the caverns at Luray, in Page County, furnish, when cut, occasional fine pieces of the so-called onyx marble, but the stone is too easily fractured and too uneven in texture to be worked economically as is noted elsewhere, even were the deposits of sufficient extent to warrant the opening of quarries. Wyoming. The resources of this State are not as yet fully known. White and greenish marbles of good quality have been stated * to occur on Cedar Creek in the extreme eastern part of the Platte River valley and the Savary section in Jthe extreme west. In the collections of the National Museum are to be seen samples of a fine-grained and compact reddish marble variegated with white and drab, from quarries in Musk- rat Cafton in township 30 west, range 65 west. The stone acquires a good polish and is somewhat harder than a major- ity of the marbles now worked. The published returns of the eleventh census give the fol- lowing figures relative to the marble industry of the United States for the year 1889 : * Stone, April 1889. n6 STONES FOR BUILDING AND DECORATION. States. Product. Cubic feet. Value. 33,792 250,000 333,305 1,171,550 309,709 1,068,305 150,552 $87,030 196,250 139,816 354,197 419,467 2,169,560 121,850 Georgia Maryland New York Tennessee Vermont . All other states' Total 3,320,213 $3,488,170 (4) THE ONYX MARBLES, OR TRAVERTINES. The so-called onyx marbles, although of the same compo- sition, differ from those of the common type in being chemical deposits rather than altered sedimentary beds. Like the stalagmitic deposits in caves, they are formed by the evapor- ation of water holding carbonate of lime in solution, and owe their banded structure and variegated colors to the intermittent character of the deposition, and the presence or absence of various impurities, mainly metallic oxides. The term onyx, as commonly applied is a misnomer, and has been given merely because in their banded appearance they somewhat resemble the true onyx, which is a variety of agate. The stone is prop- erly a travertine. It is an interesting illustration of the mis- leading character of popular names that the onyx marbles, and particularly those from Algeria and Egypt, are so universally known as alabaster, while true alabaster is a pure white and compact variety of gypsum; in fact the alabaster boxes men- tioned in the scriptures, as used for holding precious ointments, are said to have been in reality constructed of travertine. STONES FOR BUILDING AND DECORATION. Owing to their translucency, delicacy and variety of colors, the readiness with which they can be worked and the high polish which they admit of, these marbles have long been favorites for smaller ornamentation and highly decorative work, and will doubtless long so continue. As with the red granites of Syene, and the green and red porphyries, the ancient Egyptians knew their value, and utilized them as long ago as the time of the Rameses ; the ancient Romans, too, appreciated their beauty and utilized them in the construction of their monuments and the interior decorations of their houses. The only onyx marble until recently of any commercial im- portance within the limits of the United States, is found at San Luis Obispo, California. The stone as I have seen it in the dealers' shops in San Francisco, and as shown in the National collection, is nearly white, finely banded, translucent, and takes a beautiful surface and polish. It lacks the variety of colors of the Mexican onyx, but is nevertheless a beautiful stone and if it can be obtained in any abundance will find a ready market. According to Mr. Angell,* the San Luis Obispo onyx quar- ries are situated in the heart of the Santa Lucia Mountains. There are two openings on sections 9 and 16, township 31 south, range 15 east, Mount Diablo meridian. The two out-croppings so far discovered are about half a mile apart, one on the northern and one on the southern slope of a hill which rises about So feet between them. Whether or no they are portions of the same bed is yet to be determined. The strike of the two is not the same. The rock of the north- ern outcrop is milky white. That of the southern variegated in yellow, green, pink, blue, golden and red colors beautifully * Tenth Annual Report State Mineralogist of California, 1890, p. 584. Il8 STONES FOR BUILDING AND DECORATION. blended. The enclosing rock is sandy slate, the ledges of the onyx standing nearly perpendicular and having a thickness of about 1 6 feet. The stone is stated to be worth about $100.00 a ton in San Francisco, and when polished about $10.00 a square foot. A dull red resinous, or yellow travertine, but which occurs only in small masses, has been quarried in times past at Suisin in the same State, and a beautiful light emerald green variety in Siskiyou county, but neither deposit, so far as can be learn- ed, is sufficiently extensive to have any great commercial value. Other onyx marbles are mentioned in the various reports of the the State mineralogist as occuring in the State, but not having seen samples, the writer is obliged to quote wholly from other authorities. An orange and blue variety is stated to occur in the southeast quarter of section 9, township 32 south, range 15 east, Mt. Diablo meridian. An onyx marble is also stated to occur in the form of veins and bunches in the limestone of Slover Mountain near the town of Colton in San Bernardino County. The stone is described as beautifully striped and banded with various shades of yellow and brown. It is regarded as a promising stone.* The serpentines and other marbles occuring here are noted elsewhere. A recent find of high grade onyx is reported from near Prescott, in Yavapai County, Arizona. The colors are given as green, white, black and white, milky, red, old gold and brown. At the time this work goes to press the writer has had no opportunity of personally inspecting the stone, and hence at- tempts to give no detailed description of its qualities. Quarries of the oynx marbles have on sundry occasions been opened in the stalagmitic deposits of caves in Missouri, but the * Annual Report of State Mineralogist. 1888, p. 509. STONES FOR BUILDING AND DECORATION. 1 19 stone is stated by dealers to be soft and of too dull a color to be greatly desirable. The similar deposits in the Luray caves of Virginia have furnished occasional blocks of considerable beauty, but the rock is, as a rule, too coarsely crystalline and too friable, to be of value, even when the colors are good. At least this is the case with a majority of the blocks in the National collections at Washington. I am told by Dr. G. Brown Goode, however, that it is a common thing to find in the country mansions of Virginia, very handsome mantels of this stone, but which have as a rule been cut from stray blocks found loose in the fields. As above noted, the San Luis Obispo stone is the one of chief commercial importance at present. The Mexican onyx differs from that of California, in presenting a greater variety of colors. Creamy-white, amber yellow, streaked or blotched with green or red, to uniformly light green or green with red blotches are common. Cut across the grain the stone often presents a beautifully banded structure like the grain of wood. Cut in this way, however, it is very weak, and needs always to be backed by slabs of stronger and cheaper material. The stone occurs in such abundance at Tecali, State of Puebla, Mexico, that it has been used in rough blocks for building the native houses, and I am informed by M. Ferrari, of the Mexican Geological Commis- sion, that the name Tecalli was given the locality on this account, the word being derived from two Aztec words tetl, stone, and calli, house. When cut into thin slabs the stone is quite translucent, and I am informed by this same authority that it has been used in this form for window panes in some of the public buildings of the City of Mexico. M. Mariano Bar- cena, who read a paper describing the stone and its mode of occurrence before the Philadelphia Academy of Science, at the time of the Exposition in 1876, reported on it as having a specific gravity otf 2.90 (equal to a weight of 181 pounds to the I2O STONES FOR BUILDING AND DECORATION. cubic foot), and consisting of 96.36 per cent carbonate of lime and magnesia, some 3.54 per cent sulphate of lime and o.io per cent water, oxides of iron and manganese, the higher colored varieties showing larger percentages of the metallic oxides. This stone is by far the most beautiful and variegated of the onyx marbles, and is now imported into the United States at the rate of many tons annually. It is used wholly for interior decorations, and is to be seen in the form of turned columns, and tops for small tables and stands, in any of the leading house-furnishing shops. Slabs of I inch in thickness are valued according to color at the rate of from $2. 50 to $6.00 per square foot in the New York market. The only other onyx m:;rbles of any great commercial im- portance now quarried are from Algeria and Egypt in northern Africa. Some slight confusion among authorities seems to exist regarding these localities. Hull, in his work on Building and Ornamental Stones published in 1872, speaks of the Egyp- tian onyx as found at Blad Recam near the Ravine of Oned Abdallah. Delesse,* however, puts down Oned (or Oued) Abdallah as in Algeria, and states that the Egyptian onyx is from quarries situated at Benisouef, about twenty-five leagues south of Cairo, on the Nile, and at Syout (or Sivat) still farther south. The Syout stone is said to be distinguishable from that of Benisouef by its paler, slightly grayish color. As the African onyx now imported is almost universally known as Egyptian onyx, it seems probable that it is from either the Beni- souef or Syout quarries, possibly both. The Egyptian stone lacks the variety of colors displayed by that of Mexico, vary- ing only from whitish to amber yellow. It is nevertheless a beautiful stone, and is utilized for furniture tops, clocks, and a *Materiauxde Construction de L'Exposition 1855, P- 158. STONES FOR BUILDING AND DECORATION. 121 variety of smaller ornamentations. The quarries were first worked by the Egyptians and later by the Romans. The Algerian stone is stated by Delesse* to occur at Ain- Tembaleck, near the river Isser, and to lie in irregular beds varying from a few inches to nearly ten feet in thickness. The stone is translucent, and of faintly white color, with a compact at times somewhat fibrous structure, and is stated to weigh about 170 pounds to the cubic foot. The Algerian, like the Egyptian quarries, are said to have furnished material for the embellishment of ancient Rome and Carthage, but for over a thousand years the quarries were completely lost sight of to be rediscovered by M. Delmont, about 1849. Samples of the Algerian stone, received at Washington from the Musee Na- tionale de France, are nearly white or of a faint yellowish color, and in no way remarkable for their beauty. Travertines or stalagmitic marbles (Lalbatre Calcaire] are stated by Delesse f to be abundant in many parts of the prov- ince of Tuscany, Italy, notably at Serravezza, Vignone, San- Filippo, Grosseto, and Castel-Nuovo. None of these, so far as I can learn, are regularly imported into the United States. Small samples in the National collections, and marked as from Civita Vecchia and Montalto, are of a yellowish or dull white color, and not remarkably beautiful. Other stalagmitic mar- bles in this same collection, but not of sufficient beauty to be of great value, are from Jura in France, and Stuttgardt, Germany. The various cavities and caves in the limestone forming the rock of Gibraltar often furnish small masses of a handsomely banded brownish stalagmite which is cut into small ornaments and widely circulated. The National collec- tions show a small mounted canon and several irregular blocks * Materiaux de Construction de L'Exposition Universelle, 1855, p. 155. f Op. sit., 176. 122 STONES FOR BUILDING AND DECORATION. and slabs of this material, which, however, ranks rather as a curiosity than as a commercial article. The above list includes all the travertines, onyx marbles, calcareous alabasters, or whatever they may be called, that, so far as the writer is aware, occur in such form as to be of any commercial value. A quarry within the limits of the United States, good in quality and in quantity, will prove a rich " find " for somebody. (5) LIMESTONES AND DOLOMITES OTHER THAN MARBLES. Alabama. A dark compact limestone occurs near Calera, in Shelby County, and a light-colored, finely fossiliferous one near Dickson, in Colbert County. The last mentioned closely resembles in general appearance the celebrated limestone from Bedford, Indiana, to be noticed later. It appears of good qual- ity, and works readily. Arkansas. Oolitic limestone suitable for building, and hav- ing the reputation of being very durable, is stated by Mr. Owen* to occur near Batesville, in Independence County. Prof. Branner also reports f a cream-colored magnesian lime- stone of good quality as occurring in the vicinity of Eureka Springs in Carroll County. Colorado. The National collections from this State show a coarse, reddish limestone from Jefferson County, and also a very compact, finely crystalline black stone, traversed by a coarse net-work of very fine white lines, from Pitkin in Gunni- son County. This last stone takes a polish, and might almost be classed as a marble. Neither stone is now quarried to any extent. * Geology of Arkansas, vol. i. p. 220. f Stone, Oct. 1889, p. 93. STONES FOR BUILDING AND DECORATION. 123 Florida. This State at present furnishes scarcely anything in the line of building stone, nor is there much demand for any other form of building material than wood. On Anastasia Island, about two miles from Saint Augustine, there was formerly quarried to a considerable extent a very coarse and porous shell limestone which was used in the construction of the old city of Saint Augustine and of Fort Marion, which was built about the middle of the eighteenth century. The rock is composed simply of shells of a bivalve mollusk, more or less broken and cemented together by the same material in a more finely divided state. Fragments of shells an inch or more in diameter occur. The rock is loosely compacted and very por- ous, but in a mild climate like that of Florida is nevertheless durable. The quarries were opened upwards of two hun- dred years ago, but the stone is not now extensively used, ow- ing in part to the dampness of houses constructed of it, and in part to the cheapness of wood. The rock, which is popularly known as Coquina (the Spanish word for shell), is of Upper Eocene age. In the quarries the stone lies within a few feet of the surface, and can be cut out with an ax, in sizes and shapes to suit. The oolitic limestone occurring at Key West has been quarried and used in the construction of numerous private and public buildings in that vicinity. It is of too loose and porous a texture to be of value for other than local use. Illinois. No siliceous crystalline rocks of any kind are to be found within the State limits, almost the entire product being limestone or dolomite, with a few quarries of sandstone, which are noticed on p. 260. According to Professor Conover* the State embraces rocks representing most of the epochs of the Silurian, Devonian, and Carboniferous ages. Over the * Report of Tenth Census, vol. x. 1880. 124 STONES FOR BUILDING AND DECORATION. greater part of its area these rocks have been but little dis- turbed, and occur with beds approximately horizontal or in- clined at a small angle to the horizon. The surface of the State is almost everywhere covered by a variable depth of the looser deposits of the Tertiary and Qua- ternary ages. Owing partly to the nature of the rock, but most largely in all probabilities to these subsequent deposits, a very large portion of the country presents a very level or slightly undulating prairie surface, within the limits of which are few rock exposures. This is true of the whole central and eastern part of the State, the larger portion of its territory. Skirting this great area on all sides except the east, is a country of very different character, though the change is gradual a valley country with very marked water courses, which cut through the beds of clay and sand to and into the rock formations below. Throughout the greater part of this area the rocks immediately underlying are Silurian, Devonian, or Sub-carboniferous, all of which furnish excellent building materials, and but few localities of considerable area are found where at least a fair building material cannot easily be obtained. The most notable of the limestones of this State is the fine grained, very light-colored Niagara stone, quarried in the vicin- ity of Lemont and Joliet, in Will County. The Lemont quar- ries lie on both sides of the Illinois and Lake Michigan Canal, and the beds of stone are quarried to their lower limits through a variable thickness of from 12 to 40 feet. The stone here is uniformly a fine-grained, homogeneous, light-drab' limestone, occurring in beds from 6 to 24, and sometimes 30 inches in thickness. The beds are divided vertically by seams occurring at intervals of from 12 to 50 feet, and continuing with smooth faces for long distances, and also by a second set running nearly at right angles with the first, but only continuous be- STOA T ES FOR BUILDING AND DECORATION. 125 tween massive joints and at irregular intervals. This structure renders the rock very easily quarried and obtainable in blocks of almost any required dimensions. The stone is soft and easily worked, taking readily a smooth surface, but no polish. It can be turned on a lathe, and is made into balustrades and other forms of ornamental work. It can be carved in bas relief, but is not sufficiently tough for high reliefs that are to be exposed to the weather. To produce smooth surfaces for flagging, the stone is planed by machines somewhat similar to those used in planing iron. The stone from the immediate vicinity of Lemont is said to contain less iron and to tarnish less readily than that a few miles distant at Joliet. The stone in the quarry contains much moisture, and dur- ing cold weather care has to be taken to avoid injury by freez- ing before the quarry water has evaporated. This causes a con- siderable annual expense in making earth protections, except in those few quarries that are so situated that they can be flooded with water during the winter months. The quarries extend for nearly 4 miles below Lemont, where a gap occurs, to just below Lockport, from which point a line of closely-adjoining quarries extend to below Joliet. The finer varieties of the stone do not seem well fitted for heavy masonry in damp situations. Fine clay seams abound, which are invisible when the stone is first quarried, and which under favorable circumstances do not develop at all, but when exposed to heavy pressure or to alternate moisture and dryness, accompanied by frost, they are soon developed, and often render the stone worthless. Even the best varieties of the stone tarnish after a short exposure, especially in cities where soft coal is burned. The Joliet quarries extend from a point about a mile below Lockport to the same distance below Joliet. Two distinct varieties of stone occur. That quarried from the lower beds 126 STONES FOR BUILDING AND DECORATION. on the right bank of the river is as a rule rougher, more coarsely textured, and tarnishes more readily than that from the higher levels. It is now but little used, except for heavy masonry. In the quarries back from the river, on the higher levels, the stone is fine grained, more homogeneous, and in this respect fully equal to the Lemont stones. The beds now worked are from 3 to 4 feet in thickness, and large blocks are obtainable. Most of it seems to weather-stain rather more than that from Lemont. The value of the stone quarried at these two places is probably fully equal to that of all the other stone quarried in the State.* Three large quarries are worked in these same formations at Batavia, but as a rule the stone is coarser and more difficult to work than those just described. Other quarries occur at Thornton and Blue Island, Cook County, and other parts of the State. Within the city limits of Chicago there is quarried from this same formation a coarser somewhat cellular stone, that from its unique character perhaps merits a special descrip- tion. According to Huntf this stone when pure is a nearly white granular crystalline dolomite, containing 54.6 per cent carbonate of lime. It, however, contains so large a portion of bituminous matter, that blocks sometimes become quite black on exposure. The color fades somewhat in time, but the petroleum odor is often perceptible for long distances. The stone has been used to some extent for building purposes, as notably in the First Presbyterian Church in Chicago. The * These beds were formerly described as composed of light buff stone, while the deeper portions of the quarries now furnish " bluestone." The difference results from the difference in amount of oxidation of the small quantity of iron disseminated through the whole mass, the change having resulted from atmos- pheric influences. The same change must ultimately take place in all the blue- stone which is brought to the surface. (Geology of Illinois, vol. iv. p. 220.) f Chemical and Geological Essays, p. 172. STONES FOR BUILDING AND DECORATION. I2/ gummy bituminous matter causes the dust from the streets to adhere to exposed surfaces, thus giving the buildings a peculiar antique appearance. We are informed by Mr. Batchen that this pseudo-antique appearance is greatly admired by some. The presence of the bitumen is beneficial in at least one re- spect, in that it renders the stone less pervious to moisture, and hence less liable to disintegration by freezing. Lower Silurian (Trenton) limestones and dolomities are quite extensively quarried in Jo Daviess County, and make a handsome and very durable building material. Calhoun, Alexandria, and Ogle Counties also furnish good material, but which, for the lack of space, cannot be described here in detail. At various points in Whiteside and Hopkins Counties there are outcrops of limestones belonging to the Cincinnati group, a part of which will furnish durable building material. The stone needs, however, to be selected with the greatest care, since all the beds are not of equal quality. At Jonesborough, in Union County, there occurs a fine, even-grained, compact, beautifully oolitic stone that cuts to a sharp even edge, and seems admirably adapted for carved work and general building purposes as well. Specimens in the Na- tional Museum are of a lighter color than the Bedford (Ind.) oolitic and take a better polish. We have had no means of ascertaining its lasting qualities, but it is stated* to be liable to injury from frost when exposed in damp places. The stone is of Carboniferous age. Other oolitic stones occur at Rose- clair, in Hardin County. They are of a dark bluish-gray color and take a good polish. There are many other localities in the State which furnish excellent varieties of building stone. These can not be men- tioned here for lack of space. Interested parties are therefore * Report of Tenth Census, vol. x. p. 225. 128 STONES FOR BUILDING AND DECORATION. referred to the National Museum collections and to the report of the Tenth Census. Indiana. The limestones of Indiana, such as are quarried for architectural purposes, belong either to the Upper Silurian or sub-Carboniferous formations in the central and southern part of the State. Few quarries of any importance lie north of Indianapolis, and of such as do the output is used mainly for the manufacture of quicklime. According to Prof. Collett* the southeastern part of the state supplies a large quantity of stone for foundations and rubble masonry from the bluffs along the Ohio River and which extend through Wayne, Union, Fayette, Franklin, Dearborn, Ohio, and Switzerland, west to Clark County, besides being found to some extent in the coun- ties adjoining these to the west, which are included in the Lower Silurian geological range. Close-grained, compact, magnesian limestones are largely quarried in the counties bordering the above on the west, forming a belt extending northward from the Ohio to the Wabash River in Carroll, Cash, Miami, Wabash and Hunting- ton, and to some extent in the counties to the northeast of these. The stone lies in even beds, having a thickness of from a few inches to two or more feet, and is especially adapted to work in foundations, piers, abutments and massive range work where great strength is required. The thinner strata furnish, at a low cost, excellent slabs for flagging and curbstones. From Warren County at the extreme west of the State, southwesterly to the Ohio River, in a gradually widening range, the valuable limestones of the Keokuk group, (sub-Carbonifer- ous), the sand stones of the Chester, and oolitic limestones of the intermediate St. Louis group, are quarried. By far the most beautiful and valuable of this stone for architectural pur- * Twelfth Annual Report State Geologist, 1882, p. 20. STONES FOR BUILDING AND DECORATION. 1 29 poses, is the oolitic variety from Lawrence, Monroe, Owen, Crawford, Harrison and Washington Counties. The supply is inexhaustible, as it lies in massive strata of twenty to seventy feet thick, over an area of more than seventy square miles. The Lawrence County stone is extensively quarried near Bedford and is popularly known as " Bedford stone " or " Bed- ford oolite." The rock is of fine even texture, and is composed of small rounded concretionary grains of about the size of a grain of mustard seed compactly cemented together by crys- talline lime or calcite. The stone is soft, but tenacious (speci- mens having borne a pressure of 12,000 pounds per square inch), and works readily in every direction. It is therefore a great favorite for carved work, and is used more extensively for this purpose than any other of our limestones. No better example of the adaptability of the stone for this purpose can be given than the elegant mansion of Mr. C. J. Vanderbilt, on Fifth avenue, in New York City. Unfortunately, as is usually the case with light limestones, this stains badly in cities \lj|tere there is a great amount of manufacturing, as is only too well illustrated in the case referred to. . \ Although the quarries have been worked systematically for but a few years, the stone is already widely known, and is com- ing into very general use in nearly every city of importance in the country. At the locality above referred to the stone occurs in a solid bed, that has been worked to a depth of 40 feet without reaching the bottom. Stones from the other counties mentioned are very similar in general appearance, but not always so distinctly oolitic and often contain a considerable percentage of bituminous matter. Samples exhibited at the Museum from near Corydon in Har- rison County are of a beautifully fine and even oolitic structure, very light color, firm and compact. They resemble the oolitic stone from Princeton, Kentucky, more closely than any other, ISO STONES FOR BUILDING AND DECORATION. but are much more compact. The stone is stated to occur in inexhaustible quantities. The Washington County deposit at Salem is said to be an exceptionally fine one, there being a solid bed of the oolite 30 feet in thickness, with only about 5 feet of cap rock. Near Silverville, in Lawrence County, there occurs a very fine-grained compact stone of a drab color, that acquires readily a smooth and even surface. An attempt has been made to utilize this for lithographic purposes, but, it is stated, with in- different success. It bears a close resemblance to the darker variety of the well-known Bavarian lithographic stone, but is somewhat harder. At Anderson, in Madison County, a light-colored, fine-grained stone occurs in beds of from 4 to 12 inches in thickness, which is used locally for flagging and general trimming purposes. lozva. Although this State abounds in limestones and dolomites to the exclusion of almost all other varieties of build- ing stone, but little of the material now quarried is of such a nature as ever to acquire more than a local reputation. Though having altogether more than three times the number of quarries found in Illinois, these are mostly small affairs, and the value of the total product is but little more than one-half that of the latter State. At the time of the taking of the Tenth Census the whole number of quarries in the State was 131, of which 128 were of limestone and dolomites, and the remaining three of sandstone, which are mentioned on p. 261. At the present time the most important quarries are situ- ated in the Niagara* division of the Upper Silurian formations, in the vicinity of Stone City, Jones County ; Farley, Dubuque County, and in various portions of Jackson, Cedar, Clinton, and Scott Counties. The Jones County stone is a very light-colored, fine-grained and compact bituminous dolomite. That from Farley is very similar in general appearance, but contains less STONES FOR BUILDING AND DECORATION. 131 bituminous matter. In the small blocks displayed at the National Museum the stones appear of good quality, but we have had no opportunity of learning their weathering qualities. A finely crystalline light-colored limestone of sub-Carboni- ferous age is quite extensively quarried near Burlington, in Des Moines County. According to Professor McGee * this stone, which is practically identical with that of Keokuk, in Lee County, is used chiefly for common masonry, and only occasionally for dressed work. The upper beds are " nearly white in color, fine, compact, homogeneous, and hard, with a conchoidal or splintery fracture, like the so-called lithographic limestone of nearly the same geological age. This stone has been used to some extent for ornamental purposes, but con- tains too many incipient fractures, and is too liable to unex- pected disruption to be of special value." Near Le Grand and Montour, in Tama County, there occurs a magnesian limestone of the same age as that just de- scribed, which is fine-grained, compact, and generally buff or whitish in color. The coarser portions are extensively used for heavy masonry, while the finer grades, which are often beauti- fully veined with iron oxidies, are used for ornamental work under the name of Iowa marbles. Some of the stone from this locality is oolitic. Similar stones are extensively quarried at Iowa Falls, and at Humboldt and Dakota, in Humboldt County. Limestones and dolomites belonging to the St. Louis epoch of the sub-Carboniferous age are quite extensively quar- ried in various parts of Lee, Des Moines, Henry, Washington, Van Buren, Jefferson, Keokuk, Wapello, Manhaska, Marion, Story, Hamilton, and Webster Counties. That from near Farmington, Van Buren County, varies from light buff to nearly white in color, is fine-grained, and has been quarried for * Report of Tenth Census, vol. x. p. 261. 132 STONES FOR BUILDING AND DECORATION. lithographic purposes. It is, however, no longer used, having been found to contain too many dry seams often cemented by crystalline carbonate of lime. At Chequest the limestone takes a fair polish and is known as Chequest marble. In the Devonian limestones near Iowa City and Roberts Ferry there frequently occur masses of fossil coral (Acervularia davidsoni) which, when cut and polished, form beautiful orna- ments and paper-weights, though of small size. They are known popularly as bird's-eye and fish-egg marbles, and have already been noticed (ante, p. 92). Kansas. The limestones and dolomites of this State are, as a rule, of a light color, soft and porous, and incapable of re- ceiving a polish such as will fit them for any form of ornamental work. Many of them are cellular and loosely compacted, being made up in large part of a small fossil rhizopod about the size of a grain of wheat and known under the name of fusulina. Such stones are obviously unfitted for exposed work in localities subject to great extremes of temperature, although they may be very durable in mild or dry climates. Those at present quarried are almost without exception of Car- boniferous or Permian age, and occur only in thin beds, varying from a few inches to 8 or 10 feet in thickness. Near Irving their occurs a light-colored, soft, thin-bedded stone, which has in times past been used for building purposes in Atchison and Kansas City. It is soft and easily quarried and for ordinary construction requires but little dressing. At Frankfort a similar stone occurs which has been used to some extent for buildings, though principally for foundations. Some of the stones from these localities are of very poor quality, being soft and quite cellular through the breaking away of the small fossils above referred to. Atchison, in the same county, has quarries of a darker, more compact stone, which are worked for local use. STONES FOR BUILDING AND DECORATION. 133 In the vicinity of Topeka there are quarried light-colored, compact, finely fossiliferous dolomites and limestones which work very readily, and which have been used in the construc- tion of about thirty-five common buildings in that city, besides a church, school, and opera houses in Emporia. They have also been used in Parsons, in Labette County, and neighboring towns in Missouri. Near Lane, in Franklin County, gray and buff limestones are quarried and used quite extensively in Ottawa and Garnett, in the same State, though some have been shipped to Chicago. The buff variety is sometimes oolitic, resembling to some extent the Bedford (Indiana) stone. The texture is firm and compact, and it acquires a good surface and polish. The gray variety is coarser, and often somewhat cellular, owing to the imperfect filling of the spaces between the fossil particles of which it is composed. A section of the quarry shows the gray stone to occur in a bed about 4 feet in thickness, and the buff oolitic about 6 feet in thickness, the layers of which vary from 18 to 24 inches each. Near Marion Center, in Marion County, there is quarried a light-drab cellular magnesian limestone of Permian age, that has been used in the construction of the asylum for the blind and insane at Wyandotte and Topeka, in this State. Similar stones are quarried at Cottonwood, in Chase County. The stratum of quarry rock here is some 6 feet in thickness and blocks of any desired size and of thickness not exceeding 2^ feet can be obtained. The principal markets for these stones are Kansas City, Missouri ; Lincoln and Omaha, Nebraska ; Pueblo and Denver, Colorado, and Atchison, Topeka, and Leavenworth, Kansas. In the vicinity of Fort Scott are some half a dozen irregularly worked quarries which furnish stone for building foundations and pavements in the near vicinity. The stone is dark-colored, fine-grained, and semi-crystalline, and is said to 134 STONES FOR BUILDING AND DECORATION. stand the wear of from ten to fifteen years' exposure very well. It turns to a brownish color on long exposure and is strong enough for ordinary structures. The stone quarried at Winfield is a light-colored, fine-grained cellular rock and so soft as to be quarried by means of plug and feathers only, the holes being first bored by means of a common auger without point. It is a handsome stone and has a good reputation for durability. It is used mostly in this State, though some is shipped to Kansas City, Missouri. Many of the towns in Butler County produce fine-grained, light-colored limestones suitable for rough building in the im- mediate vicinity, but not at all suitable for ornamental work. Kentucky. Although the building stones of this State are entirely unknown in our principal markets, and but few of them have more than a strictly local reputation, it by no means follows that there is any lack of material or that it is at all in- ferior in quality. While it is true that no marbles or granites of importance are found, yet there abound limestones of the finest quality and in inexhaustible quanities. The oolitic lime- stones of this State are without superiors, if indeed they have equals. In Todd, Grayson, Meade, Simpson, Christian, and Caldwell Counties oolitic stones occur of very light, almost white color, and excellent quality. The varieties from Litch- field and Princeton are especially worthy of mention. The oolitic character is very pronounced in these stones, and while in some cases the production of a perfect surface is impossible, owing to the breaking away of these minute rounded grains, still in the better qualities the sharp edges and smooth surfaces are as readily acquired as on the celebrated Bedford (Indiana) or other stones of this character. These are superior to the Bedford stone, moreover, in their clear and uniform colors; never, so far as observed, being blotched with oil, as is the latter. Professor Proctor informs the writer that the stone is quarried STONES FOR BUILDING AND DECORATION. 135 with ease, is easily wrought, stands pressure well, and is con- sidered one of the most reliable stones in the State. Compact fine-grained limestones of a dark drab color, tak- ing a smooth surface, but not suited for marble, are found in the towns of Franklin, Simpson County ; Lebanon, Marion County ; Russellville, Logan County, and others. A part of the Franklin County stone is fine-grained and suitable for lithographic purposes, though inferior to the imported Bava- rian stone. Very light-colored compact limestones are found also in Simpson, Logan, and Franklin Counties, but the writer has no information regarding their availability or the extent to which they are quarried. Maine. Limestone is an abundant and common rock in this State, especially in the southeastern part, in the counties of Knox and Lincoln, where it is very extensively burnt into quicklime. So far as I am aware none of the stone is utilized for building, as its colors blue and blue-black, veined with white are poorly adapted for such purposes. No stone suit- able for marble is yet known to occur in the State, though Hitchcock* expresses the opinion that such may yet be found in "the belt of Helderberg limestone running from Mataga- mon (east branch Penobscot) River northeasterly." Many samples of so-called white marble have been taken from the limestone formations about Rockland, in Knox County, but, so far as observed by the present writer, they are all too coarsely crystalline or too distinctly granular in struct- ure to be of value. Michigan. Limestone or dolomites of a character suitable for building purposes are at present but little quarried in this State, the entire value of the output during the census year of 1880 being but about $26,000. A fine-grained fossiliferous * Second Annual Report Geology of Maine, 1862, p. 428. 136 STONES FOR BUILDING AND DECORATION. dolomite of a drab color is worked at Sibley's Station, in Wayne County, and a very light colored granular rock, of sim- ilar composition, near Raisinville, in Monroe County. Near Alpena light-colored limestones are quarried which are hard, compact, and said to be durable. They are not obtainable anywhere in large quantities nor in blocks of large size, but there are numerous small openings sufficient to supply the local demand. Other localities where stone can be obtained are at Trenton, near Detroit, and upon Macon Creek, both in Monroe County. The stone is apt to contain dry seams and requires care in selecting. These are all of Devonian age. Minnesota. The Lower Silurian limestones and dolomites of this State, which are at present the only ones quarried, are nearly all of a light buff, drab, or blue color, fine-grained and compact, though in some cases cellular and semi-crystalline. According to Professor Winchell* the stone appears in the bluffs of the Mississippi River and St. Croix Valley, and is quarried at all points (except Lake City) where there is any demand between Stillwater and Winona, along the Missis- sippi Valley on the Minnesota side, and also at several places farther west, as at Caledonia, in Houston County, Lanesbor- ough and Rushford, in Fillmore County, and at points in Winona County. At Stillwater the rock is a silicious dolomite of a light buff color. In the ledge, which is about 45 feet thick, it occurs in alternate bands of compact and cellular rock varying from 3 to 6 feet in thickness. The coarser variety is most durable and is used in heavy masonry, as bridges and foundations. The finer variety is used for house trimming, ashlar work and tomb- stones. At St. Paul the rock is a fine light-bluish semi-crystalline * Report Tenth Census, p. 249, and Geology of Minnesota, vol. T. STONES FOR BUILDING AND DECORATION. magnesian limestone. It is usually quite regularly stratified, and occurs in beds from 3 to 24 inches in thickness, with joints from 10 to 30 feet apart. Blocks 10 by 5 by 2 feet can be obtained if desired. It is used only locally. At Minne- apolis the rock is quite similar, though sometimes slightly fossiliferous or mottled with argillaceous spots. It was formerly used almost exclusively in Minneapolis, but is now being grad- ually replaced by stone from the neighboring States. In speaking of these stones Professor Winchell says: * " In the use of the Trenton limestone quarried at St. Paul and Minneapolis regard should be had constantly to its laminated structure. The beds quarried now are as they were originally deposited, and as cut for use embrace in every block many layers of from one-half to two inches in thickness. These consist of alternating clayey and calcareous portions, the latter constituting the hard and enduring part of t|ie stone. These layers are not always distinct and continuous over large surfaces, but they blend or shade into each other every few inches. Yet in process of time, under natural weathering, they get separated so as to fall apart, the clayey matter disintegrat- ing first and causing the calcareous structure which sustains the whole to break up into small sheets or fragments. Hence this stone should never be placed on edge, but in the same posi- tion it occupied in the quarry. It should never be allowed to occupy projecting or exposed parts of a building. More es- pecially if it be on edge and in a projecting cornice or capital it is the source of weakness to the structure, as well as of dan- ger to all passers, from the dropping of sheets or fragments as the weather, by wet or frost, separates them from each other. Its color is also against its being put in the exposed and orna- mental parts of a structure. . . . The color of the Trenton * Preliminary Report on Building Stone, etc., 1889, p. 33. 138 STONES FOR BUILDING AND DECORATION. makes it very suitable for foundations and for the ranges below the water-table, but even there it should be well bedded in mortar and protected by the water-table in order to keep out the water." At Red Wing, in Goodhue County, the stone is quarried only for local building and for burning into quicklime. Blocks as large as can conveniently be handled can be obtained. At Frontenac, in the same county, the stone is of buff or gray color, medium fine, and quite cellular. This rock is considered one of the best in the State, and is used for all varieties of building purposes, as well as for bases and tombstones. Blocks n by 7 by 5^ ffcet and weighing 18 tons have been taken out, which is about as large as the quarries will furnish. It is said to work with comparative ease, and to withstand the weather well. Although having been in use longer than any other stone in the State, it has not as yet shown any change what- ever from atmospheric influences. Its powers of resistance to pressure vary from 5,000 to 7,000 pounds per square inch. At Kasota and Mendota, in Le Seuer County, the dolomite is of a buff or rusty pink color, of homogeneous texture, and very strong and durable. It withstands a pressure of 10,000 pounds per square inch without crushing. Blocks 10 by 11 by I foot in thickness can be obtained. It is quite generally used throughout the State, the pink variety being most admired and bringing the highest price. At Mankato, in Blue Earth County, the rock is also a dolo- mite, buff in color, fine, compact, and semi-crystalline, some- times cellular. Blocks 20 by 10 by 6 feet can be obtained from the quarries. At Winona the dolomite is quarried for general building purposes, flagging, and burning into lime. It is of a buff color, usually fine and uniform in texture, though sometimes contain- STONES FOR BUILDING AND DECORATION. 139 ing cherty lumps, and porous. Blocks of any size that can be handled may be taken from the quarries. Missouri. As stated by Professor Broadhead,* the limestone quarries of this State have not as yet been much developed, and few have the dignity of a merchantable product. It is probable that under 25,000 square miles of the State of Mis- souri there may be found good quarries of limestone. A third of this area may include beds of lower Carboniferous limestone, and two thirds may include the magnesian limestone series of the upper Cambrian. Good quarries of the lower (or sub-) Carboniferous lime- stones, very suitable for building purposes, may be opened in the counties from Cape Girardeau to Clark, and from St. Charles to Howard, as well as in Saline, Pettis, Henry, Cedar, Lawrence, Green, Jasper, Newton, MacDonald and Barry. Excellent quarries of the Burlington beds have been opened at Louisville, Hannibal, Sedalia, and other places. These stones are usually of a bluish, gray, or brown color, somewhat coarse in texture, and most of them have proven very durable. The chief objection to the stone is said to be the rough bed- ding plane and, in quarrying, the frequent occurrence of chert beds. The Keokuk group of the sub-Carboniferous is also an im- portant source of quarry rock and material for lime. The best beds are found in Green, Lawrence, Newton and Jasper Counties. Like the stones just described they are coarse grained but of a deeper blue-gray color. There are well devel- oped quarries in Greenfield, Ashgrove, Springfield, Pierce City, Carthage and Neosho. At the latter place the stone is beauti- fully oolitic. The St. Louis limestone, well exposed in the city of St. Louis and at St. Charles, is also a useful stone. * Building Trades Journal, July, 1888. I4O STONES FOR BUILDING AND DECORATION. Ordinarily it is strong, and looks well in structure, reflecting a more uniform light drab color, which is permanent on expos- ure. The beds of this limestone as found at St. Genevieve are oolitic. An attempt was made about fifteen years ago to introduce stone from the Upper Trenton beds into the St. Louis market, but experience proved the rock to be wanting in continued elements of beauty. The stone would polish well and present a pleasing appearance at first, but it was not sufficiently uniform in texture, and a certain fossil which was abundant was too soon disintegrated by atmospheric agencies. The quarry was therefore abandoned. A very fine-grained and compact limestone of a dark drab color occurs near Saverton, in Rails County, which has been used to some extent for lithographic purposes. Stones from other localities are mostly compact, and of light or dull red color. A very light encrinital stone is quarried in the vicinity of Hamilton and Bear Creek, in Marion County. Nebraska. According to Professor Aughey,* Carbonifer- ous limestones of such quality as to render them suitable for building purposes are to be found in Richardson, Pawnee, Gage, Johnson, Nemaha, Otoe, and Cass Counties. Many of these as those of Johnson County, are made up almost wholly of minute fossils of the size and shape of a grain of wheat, and known techni- cally asfusu/ina. In Nemaha and Otoe Counties the beds are exposed along the Missouri River and are here quarried and used for building. One of the best and most massive lime- stones of the State occurs below Plattsmouth in Cass County, on the banks of the river. Unfortunately, the great thickness of the superficial deposits here renders the quarries very expensive in working. At La Platte, in Sarpy County, near * Physical Geography and Geology of Nebraska, p. 311. STONES FOR BUILDING AND DECORATION. 14! the line of the Burlington and Missouri Railroad there is also a fine bed of siliceous limestone, which has been used in the con- struction of the United States post-office and court-house in Lincoln. The stone contains innumerable fusulina impressions and is adapted to only general building, not monumental work. Another exposure of this same stone occurs farther up the Platte River and which has been worked on the river bank opposite South Bend. This stone has been used in the wing of the Capitol building at Lincoln. At Syracuse, in Otoe County, are quarries of impure, variously colored limestones, from whence large quantities of building material have been taken. The Cretaceous limestones of this State are stated to like- wise furnish a quantity of excellent stone. So far as the pres- ent writer has had opportunity of examining, few, if any, of these or the other stones described are of such a nature as to ever be in great demand outside of the limits of the State. New York. According to Professor Smock,* the limestones quarried for building stones in this State belong to the follow- ing named formations, beginning with the lowest in the geo- logical scale : Calciferous, Chazy, Trenton, Niagara, Lower Helderberg, Upper Helderberg or Corniferous and the Tully limestones. These will be here considered in the order given. Rocks of the Calciferous formation may be traced along the Mohawk valley, in Montgomery, Herkimer and Oneida Coun- ties, and are quarried in numerous instances, as at Little Falls, Canajoharie and Sandhill. The rock is a more or less siliceous magnesian limestone, of a drab, blue-gray or blue-black color, and said to be, as a rule, strong and durable. It is largely used for general building. * Bulletin No. 3, New York State Museum, 1888, p. 20. 142 STONES FOR BUILDING AND DECORATION. The Chazy limestone is seen in Clinton in its typical devel- opment, and affords strong and heavy stone at various quar- ries in the Champlain valley, as at Willsboro Point and near Plattsburgh. The Trenton formation occupies the Mohawk and Champlain valleys, a broader zone around the western sides of the Adirondack region, and the St. Lawrence valley from the Canada line southwest to Lake Ontario. The counties of Montgomery, Fulton, Herkimer, Oneida, Lew r is, Jefferson, St. Lawrence, Hamilton, Clinton, Essex, Warren and Saratoga all have outcrops of limestone referable to this age. The stone varies greatly in different localities, or at times, even in the same outcrop, the same quarry sometimes yielding both marble and coarse common rock suitable only for building. The Niagara limestone has its greatest development near the' Niagara River and is quarried at Lockport and Rochester. At Lockport the stone is gray, thick bedded and subcrystalline ; it has been widely used for building purposes. The Lower Hel- derberg group includes a wide variation in its limestones. The formation may be traced from the Helderberg mountains westward, south of the Mohawk river nearly to Syracuse. The lower beds are dark colored, compact, thick, and afford a stone which may be polished ; the upper beds furnish a gray, heavy bedded and strong stone which answers for heavy masonry. Quarries in the rocks of this group have been opened in the Schoharie valley at Cobbleskill, Cherry valley and at Spring- field, Otsego County; also near Hudson, in Becrafts mountain, and near Catskill. Rocks of the Upper Helderberg group also display a great diversity throughout the areas they occupy. The formation outcrops in Onondaga, Cayuga, Seneca, Mon- roe, Genesee, Erie and Ulster Counties, and is quarried at Union Springs, Waterloo, Seneca Falls, Auburn, Leroy, Wil- liamsville, Buffalo and Kingston. Only a few of the more important stones of the above- STONES FOR BUILDING AND DECORATION. 143 named formations can be here described in full, owing to lack of space ; for further information the re'ader is referred to the work quoted. At Greenport, Columbia County, a stratum of Lower Silu- rian limestone upward of 60 or 70 feet in thickness is exten- sively worked for ornamental and building purposes. The quarry proper is said to cover an area of 40 acres, and a face 30 feet high and half a mile in length has been opened. The stone is of medium texture, semi-crystalline, highly fossiliferous, and of a water-blue or gray color. It is said to have been used to some extent under the name of Coral-shell Marble for interior decorative work in Boston and other cities. On both sides of the Hudson River, at the gorge of Glens Falls, the Trenton magnesian limestones are worked both for black mar- ble and for ordinary limestone for burning into quicklime. According to Professor Smock, the quarry on the right bank the Saratoga County side of the stream shows the following section : 1 . Black slate rock in thin layers 15 feet. 2. Gray limestone 10 " 3. Black thin-bedded limestone 12 " 4. Gray limestone 2 " 5. Waxk Marble 12 " 6. Limestone 4 " Of these the marble has already been described on p. 98. The gray limestone is used for heavy masonry and general building, while the main output is used for lime making. At Willsborough and Crown Point, in Essex County, there are also extensive quarries of blue-black magnesian limestone of good quality. In various towns in Montgomery County a gray or blue-gray semi-crystalline limestone is worked for building material. The stone is said to be strong and durable, though care needs to be used in its selection. At Tribes Hill 144 STONES FOR BUILDING AND DECORATION. the stone is gray or blue-gray, in some cases almost black on a polished surface. It is used for house trimmings and ashlar work as well as bridge construction. Several churches in Am- sterdam are of this material. At Canajoharie, in this same county, are beds that furnish a blue-gray finely crystalline stone, which has been used in mill buildings at Utica, and in the churches of Fort Plain and Canajoharie. At the Indian reservation in Onondaga County a gray, compact, semi-crys- talline limestone, said to possess great strength and durability, was formerly extensively quarried, but the work has of late fallen off somewhat, owing to lack of transportation facilities. A gray crinoidal stone that takes a fair polish is also found at Onondaga, in the same county. Professor Smock describes this gray variety as resembling the best varieties of the Maine granites when finely cut. It has been used in many of the finest structures in Syracuse, includ- ing the new U. S. Government building, the Hall of Languages, Syracuse University, and several churches. At Auburn, in Cayuga County, the Upper Helderberg beds furnish large amounts of gray and blue-gray magnesian lime- stone, which has been used extensively in the public and pri- vate buildings of that place. At Lockport, in Niagara County, a fossil-bearing calcareous dolomite has been quarried for many years for general purposes of construction in New York and Rochester. The stone does not take a good surface and consequently does not polish readily, but some portions make quite showy mantels, owing to the presence of red crinoidal remains. According to Pro- fessor Julien* this stone, as used in New York city, has not proved durable. The fault, however, he regards in part due to * Report of Tenth Census, vol. x. p. 369. STONES fOR BUILDING AND DECORATION. 145 the manner in which the stone is used, about 40 per cent, of the blocks being set on edge. North Carolina. Limestones and dolomites of good quality for building purposes occur in abundance in this State, but are not extensively quarried for lack of a market or transpor- tation facilities. Near New Berne, Craven County, there occurs a very coarse cellular shell-stone of Eocene age that has been used for underpinnings and fences, but it is said not to weather well. Material of the same nature, but much finer in texture and more compact, occurs at Rocky Point, in Fender County, and which has been used in the construction of break- waters and other harbor improvements at Wilmington, in this State. A coarse, dull red dolomite occurs at Warm Springs, in Madison County, and also light blue-gray varieties, but neither are worked, as there is little demand for the material. Ohio. The limestones and dolomites of this State are almost altogether of a dull, uninteresting color, and though in many cases durable and strong, are entirely unfit for any sort of fine building and ornamental work. They are therefore used chiefly for the rough work of foundations, street paving, and flagging, and to a very large extent for making quicklime. In many instances they have been used locally for building purposes, but their qualities are not such as to cause them to be sought from a distance. At Point Marblehead, in the northern part of the State, dull, light-colored compact dolomites of Carboniferous age have been quarried for making lime and for building purposes for the past fifty years. Many buildings in the vicinity have been constructed from it, and it has also been largely used by the Government for light-houses and other structures along the lake front. Of late years its use for building has very con- siderably diminished. Near Sandusky, in Erie County, the same formations have been extensively worked, not less than 146 STONES FOR BUILDING AND DECORATION. 12 acres in the vicinity having been quarried over to a depth of 8 feet. The stone is of a dull, bluish-gray color, and is used for building, flagging, and making lime ; about one hundred and eighty houses^ in the city have been constructed from it. Near Columbus, in Franklin County, the Devonian limestones are extensively quarried, and the product has in a few instances been used for building purposes. By far the greater part of the product is, however, used as a flux for iron and for making quicklime. A dolomite from the same formations is quarried for rough building and lime burning at and near Marion, in Marion County. In Allen, Miami, Clarke, Greene, Montgomery, Preble, and several other counties the dolomites and limestones of Upper Silurian age are extensively worked, but so far as the author can learn but a small part of the quarry product is utilized for building. At Springfield the stone is buff in color and some- what porous, though it is said to be strong and durable. Near Greenfield, Ross County, and Lexington, Highland County, there are extensive quarries of a bituminous dolomite, which is largely used in Cincinnati for flagging, steps, and in the manufacture of lime. Specimens in the National Museum from these places show the stone to vary from dark grayish, distinctly laminated, to fine, compact, and homogeneous of a yellowish or buff color. The buff stone can be cut to a sharp edge, and acquires a good surface, but takes only a dull polish. So far as the author has observed this is one of the finest appearing and best working stones in the State. The Montgomery County stone is a magnesian limestone, and it is said to have acquired a good reputation. It is not now used as much as formerly, however. The stone quarried in the other localities mentioned present so little diversity of character as to need no special description. Those interested STONES FOR BUILDING AND DECORATION. 147 are referred to vol. X. of the Reports of the Tenth Census, and to vol. v. of the Reports of the Geological Survey of Ohio. Pennsylvania. The lower Silurian formations in Montgom- ery, Lancaster, and Chester Counties, which furnish the supply of marble already referred to on page 100, furnish also large quan- tities of gray or bluish-gray stone of the same composition, but owing to its color and texture unsuited for any form of orna- mental work. It is, however, extensively quarried for general building, for foundations and bridge abutments. Besides in Montgomery County, limestone is quarried for local use in Easton, Tuckerton, and Reading, Berks County, and in Ann- ville, Lebanon County; also near Harrisburg, Dauphin County ; Leaman Place, Lancaster County ; York, York County ; Bridge- port, Shiremanstown, and Carlisle, Cumberland County. The stone from the Lancaster quarries breaks with an irregular fracture; is "plucky," as the stone-cutters say, and is hence hard to work. It is, however, very durable, exposure for many years having no other apparent effect than that of a slight fading of the color. The York stone is very fine-grained, compact, and of a deep blue-black color. It takes a high polish, and but for its uneven texture might make a fine marble. In Wrightsville, in this same county, a white or bluish crystalline granular stone is quarried, which takes a fair polish, and which might perhaps be used for marble. At Chambersburg and in other parts of Franklin county the stone is a calcareous dolomite, dark in color, fine-grained, and very durable ; buildings which have stood for a century showing only a slight fading. It is used locally for rough build- ing and lime burning. At various localities near South Mountain, a limestone breccia similar to that of Frederick, Maryland, occurs, and which perhaps can be made to yield good stone for ornamental 148 STONES FOR BUILDING AND DECORATION. work. At none of the localities mentioned does the stone, so far as the writer is aware, possess such characters as to make it of value for building excepting in the immediate vicinity of the quarries, where it can be had cheaply owing to slight cost of transportation. The output as above indicated is used mainly for foundations, street paving, a flux in iron furnaces or for making quicklime.* Tennessee. A compact, finely fossiliferous, light pink spotted limestone occurs in the vicinity of Nashville, in this State, and which is quite extensively quarried for use in the near vicinity. The stone is said to be of rather poor quality, but is used on account of its accessibility. Near Chattanooga r in Hamilton County, a magnesian limestone of bluish-black color is quarried for local use. The quarry is said to be very favorably located, and the stone cheap and very durable. Light pink, finely fossiliferous, semi-crystalline limestones occur at Columbia, Maury County ; light-colored, similar-tex- tured stones at Carter's Creek; light, almost white, at Morris- town ; red, compact fossiliferous at Springville ; and compact drab and almost black dolomites near Charlotte Pike. A fine grained, compact, and light-colored oolitic stone occurs at Sherwood Station, which cuts to a sharp, smooth edge and seems a most excellent stone. So far as the author is aware, none of these are quarried for anything more than local use. Texas. Compact, fine-grained Cretaceous (?) limestones of excellent quality occur near San Saba in this State. A portion of these are entirely crystalline and acquire an excellent sur- face and polish, such as fits them for interior decorative work. Light-colored, fine-grained limestones also occur in the vi- cinity of Austin, in Travis County ; and dark mottled varieties near Burnet, in Burnet County. ^Details of quarries are to be found in vol. x. Report Tenth Census, pp. 149 to 156. STONES FOR BUILDING AND DECORATION. 149 Wisconsin. The more thickly settled portions of this State are underlain by Silurian rocks so disposed that there are but few regions where rock fit for ordinary purposes of construction can not be obtained in quantities sufficient to supply the local demand. Previous to 1880, however, with a single exception, no quarries had been worked for export beyond the state limits, and but few that had been worked for other than local markes. As a whole the stones belonging to -this class are characterized by their light colors, compact textures, and hard- ness. Many of them will take a good polish and might be used for ornamental work, but that the colors are dull and un- interesting. Such occur and are quarried to a considerable ex- tent at Byron, Fond du Lac, and Eden, in Fond du Lac County, but although the stone seems very durable, its hardness is such that it has not been used for facings or any kind of ornamental work. Coarse drab dolomites are quarried for general building at Ledyard and Kaukauna, in Outagamie County; at Neenah and Oshkosh, Winnebago County, and at Duck Creek Station, in Brown County. In various parts of Waukesha County there occurs a light drab, sometimes almost white, dolomite, which though a hard stone to cut, has been quite extensively used and with very good effect for general building. At Eden, Oak Centre and Sylvester, Green County, a similar stone occurs, which also crops out in Calumet County. Here it is of a white mottled color, takes a good polish, and is locally called marble. Near Racine there occur beds of dolomite, varying from coarse, porous, and irregularly bedded to a fine, compact, and homogeneous rock, eminently adapted for fine building material, though not well suited for ornamental work. The quarries are very extensively worked. Other quarries in the same formation occur at Milwaukee, Cedarburgh, Grafton, She- boygan, and Manitowoc. The Milwaukee quarries furnish sev- ISO STONES FOR BUILDING AND DECORATION. eral grades of building material, and of almost any necessary size. These are said to be remarkable for the great depth of excellent building stone which their working has developed. Numerous other quarries occur in Rock, Dane, and La Crosse Counties, but which can not be mentioned here for lack of space. (0)" FOREIGN LIMESTONES AND MARBLES. Bermuda. The building stones of Bermuda are altogether calcareous and fragmental. Although popularly known as coral limestones, they contain as a rule fully as large a propor- tion of shell as of coral fragments. Nearly all the quarried material belongs, according to Professor Rice,* to the drift sand-rock or ^Eolian variety, i.e., rocks made up of fragments blown inland from the beach and subsequently cemented by calcareous matter in a crystalline or subcrystalline state. The rock varies in color and texture from chalky white, fine- grained, and porous (somewhat like the French Caen stone), to a darker, coarser, but tough and compact form, in which the individual fragments, often of a pink color, are one-fourth of an inch or more in diameter. According to the authority above quoted the rock is usually very soft, and is quarried out in large blocks by means of a peculiar long-handled chisel, and afterward sawn up in sizes and shapes to suit individual cases. The harder varieties, as found at Paynter's Vale and elsewhere, are, however, worked like " any ancient limestone or marble." Most of the houses of Bermuda are stated by Professor Rice to be built of this soft, friable variety, and even the roofs are covered with the same material sawn into thin slabs. * Geology of Bermuda, Bull. 25, U. S. National Museum, 1884. STONES FOR BUILDING AND DECORATION. I$I When covered with a coating of whitewash the stone is found sufficiently durable for ordinary buildings in that climate, but if exposed to the rigors of a New England winter it would crumble rapidly. The hard rock, such as is found at Paynter's Vale and Ireland Island, " has been used in the construction of the fortifications and other government works " on the islands. " The quarry of the Royal Engineers, near Elbow Bay, appears to be in beach-rock." British Columbia. Marbles of excellent quality for general building and to some extent for ornamental work occur on Taxada Island. The colors range from gray to white, some- times handsomely mottled.* White, gray, and pinkish vari- eties are also reported from White Cliff Island ; gray, hand- somely variegated varieties from Beaver Cove, on the east coast of Vancouver's Island ; gray and mottled varieties from White Cliff Island ; gray mottled from Nimpish Lake, and a consid- erable variety from Home Lake. Canada. An outcrop of deep red marble, veined with white calcite occurs associated with red shales and sandstones a short distance east of the Calway River in the Province of Quebec. The bed is stated to be from ten to forty feet thick, and to be exposed for a distance of half a mile along the strike. f The beds of crystalline Laurentian limestone in Hastings County, Ontario Province, are capable of furnishing at various points marbles of the ordinary granular type, varying in color from white through shades of gray to nearly black. Quarries are worked in the village of Madoc, where the limestone band is some 900 feet across with a north and south trend, and also * Ann. Rep. Geol. Survey of Canada, 1887-88. f Ann. Rep. Geol. Survey of Canada, 1887-88, vol. iii., part 2, pp. 113, 114. K. 152 STONES FOR BUILDING AND DECORATION. in the township of Hungerford, where there is a bed some 500 feet in width. This last stone is described as pure white in color, clouded bluish and greenish in places, and with bands of pinkish or salmon color in other parts. The town of Renfrew is also situated on a wide band of crystalline limestone which furnishes a good marble for general building purposes. Other bands occur at Arnprior and Echo Lake.* Africa. Within a very few years there have been reopened in Algeria and Tunis the famous quarries of Numidian marbles, from whence the ancient Romans are stated to have obtained the celebrated Giallo Antico and other stones for the decoration of their houses and temples. According to Playfair, the name Numidian is incorrect, as the marbles are not found in Numidia proper, but in the prov- inces of Africa and Mauritania. " Most of the Giallo Antico," says this authority, " used in Rome was obtained from Simittu Colonia, the modern Chemtou, in the valley of Medjerda, the quarries of which are now being worked by a Belgian company ; but the most remarkable and valuable marbles are found near Kleber, in the province of Oran, in Algeria. At this point there rises an imposing mountain marked on the maps as Djebel-er-Roos, or Mountain of the Capes, but commonly called Montague grise, from its gray, arid appear- ance. On the summit of this is an elevated plateau of an ob- long form, running in an east and west direction. The soil, where any exists, is of a deep red color, and there are traces of iron everywhere, but more especially on the western side. The original color of the rock was creamy white ; in the ex- treme eastern part where the amount of iron is small, it exists very much in its natural condition, only somewhat stained with * Mineral Resources of Ontario. Report of Royal Commission, 1890. STONES FOR BUILDING AND DECORATION. 153 iron, which communicates to it a tint resembling ivory. In conjunction with this is a rose-colored variety which is capable of being worked either in large masses or in the finest orna- mentation. Here all the rock is of a uniform structure ; in the west of the plateau, however, there appears to have taken place some great earth movement. The whole of this side of the mountain has been crushed by pressure into fragments varying in size from large angular masses to the merest dust. The disintegrated mass has subsequently been cemented to- gether ; the fragments have retained to a certain extent their original rose or yellow color, while the matrix has been stained of the deepest brown or red, owing to the metallic oxides which have been carried through the fissures, the whole thus forming a beautiful breccia of endless variety and color. The matrix is as hard as the fragments it contains, so that the stone takes a beautiful polish throughout its whole surface. Between these two extreme varieties, namely, the white and rose marble on the east, and the breccias on the west, there are many others, such as the well-known yellow or giallo antico, a cippolino of almost indescribable beauty, a variety called paonazza, from its resemblance to a peacock's plumage, and a deep red species, somewhat brecciated, and resembling if not identical with the celebrated rosso antico. All of these owe their color to the iron, and the crushing force to which they have been subjected.* The National collections contain a series of these marbles, which range in color through many shades of gray, drab, siena yellow, and rose-red, and which are designated in our markets under the names of jaune, antique dore 1 , paonazzo rosso, jaune chiaro ondate, jaune rose, rose clair, breche sanguin, and jaspe rouge. All are extremely compact and hard and acquire a sur- * Geological Magazine, Dec. 1885, p. 562. 154 STONES FOR BUILDING AND DECORATION. face and polish of wonderful beauty. The United States, at present, produces nothing that can compare with them for interior decorations. Nummulitic limestone. The celebrated nummulitic lime- stone of Eocene age from Northern Africa, and which was so extensively used by the Egyptians in the construction of their pyramids, is represented in the collections of the National Museum by a 7-inch cube, the gift of Commander Gorringe, U. S. Navy. This particular block was formerly a portion of the steps leading to the obelisk at Alexandria, and was brought away at the same time as the obelisk itself. Hull states that this stone was used in the construction of Baalbec, Aleppo, and some of the cities of the Holy Land. The pyramid of Cheops in Egypt is of the same material. England. The English marbles are rarely to be met with in the American markets. The country is, however, by no means deficient in materials of this nature well suited for decorative purposes, although the white statuary varieties are stated by Hull to be wholly lacking. According to this authority beds belonging to the Devonian and Carboniferous formations furnish a good supply of colored marbles. Beds belonging to the lower Cretaceous and upper Jurassic (Purbeck and Wealden) formations have also in times past furnished small blocks used mainly in the form of slender shafts in ecclesiastical building. The National collections show a series of colored marbles, from quarries in Petitor, Ogwell, and Ashburton in Devon which compare very favorably with other and better known stones. They are as a rule of a very fine and compact texture, highly fossiliferous, and acquire an excellent surface and pol- ish. The Petitor stones vary in color from light yellowish, white and clouded, through pink and gray, light and dark band- ed, to dove, mottled with deep red. An Ashburton variety STONES FOR BUILDING AND DECORATION. 155 known as bird's-eye marble, is a dark gray stone thickly studded with small white fossil favosites. The stone is further vari- gated with small white and dull red veins. Another dark mottled variety is made up of distorted fossil corals of vary- ing sizes up to two inches in diameter imbedded in a cement so impregnated with iron oxides that a polished surface is covered with an irregular network of dull, deep red lines, form- ing a beautiful contrast with the gray, rounded fossil forms. The Ogwell stones vary from light pinkish, mottled with gray, through dull red, and red spotted and veined with gray. The well-known Bath stone or Bath oolite is a light, almost white or cream-colored oolitic limestone from quarries in the Jurassic formations which extend from the coast of Dorset, in the south of England, in a northeasterly direction through Somersetshire, Gloucestershire, Oxfordshire, Northampton- shire and Lincolnshire, to Yorkshire. In texture it is distinctly oolitic, soft, and very easy to work. Its durability when exposed in the trying climate of America is a matter of great doubt. Nevertheless, churches and cathedrals erected in the west of England as long ago as the eleventh, twelfth, and fifteenth centuries, are stated by Hull to be still in a state of good preservation. As yet the stone has been but little used in this country, though a movement has of late been on foot for its introduc- tion. Portland stone. This stone, which has been in use in England since the middle of the seventeenth century, is a lightcolored Jurassic limestone from quarries on the Isle of Portland, near Weymouth. In composition it is a nearly pure carbonate of lime, but its texture is too uneven to recommend it for other than massive structures. It was used in the construction of St. Paul's Cathedral (London), and many churches erected during the reign of Queen Anne, 156 STONES FOR BUILDING AND DECORATION. Ireland. The so-called " Irish-black " is one of the best known of the black marbles and has in times past been exten- sively imported into this country. The Angliham and Men- lough quarries from whence the stone is taken are situated about three miles north of Galway. As long ago as 1868 there were 40 feet of clearing over the beds, and at the present date the amount of clearing and pumping have greatly increased, thereby adding much to the cost of the stone. In the Angli- ham quarry there were three beds of marble, one 9 inches thick: one 12 inches thick : and one 14 inches thick. The 9 inch bed furnished the purest stone: the 12 inch bed was known as the London bed, the product being held wholly for the London market, preference being given to it on account of its capability of being cut most economically. The historic Kilkenny marble is from the quarries lying close to the river, near Archers Grove, about half a mile south east of the town of Kilkenny. The stone occurs in three varieties : shelly black, pure black and dark gray. The shelly black is the best known variety, the black background thickly studded with white shells giving it a world wide reputation. Other black marbles are found in the town of Carlow, in Donegal, Ferm- auagh, Kerry, Limerick, Mayo, Monaghan, Sligo, Tipperary and Waterford. According to G. H. Kinahan, who is author- ity for the above, * the Irish black marbles were at one time in great request, quarries in various counties being worked in great measure for exportation to England and elsewhere. The pure black varieties were used mainly for monumental pur- poses. Although in late years the best " blacks " were most in requisition, yet the black mottled or white spotted, like the famous Kilkenny stone, were much sought, as were also the * Economic Geology of Ireland. Journal Royal Geological Society of Ire- land, vol. viu. (new series), part n. 1886-87, p. 137. STOiVES FOR BUILDING AND DECORATION. 1 57 inferior varieties, used mainly for tombstones. At present the trade is very low, only the best black varieties being now in demand. EUROPE. Belgium. This country is stated by Violet * to be excep- tionally rich in colored marbles, though white varieties are entirely wanting. They are mostly of a somber or dull color, and, like the marbles of Northern France, belong, according to Delesse, f to the Carboniferous and Devonian formations. The principal varieties now quarried for exportation, as repre- sented in the collections of the National Museum, are the black of St. Anne, from Biesme, province of Namur, the blue from Couillet, near Charleroi, province of Hainaut, the reds from Cerfontaine and Merlemont, near Philippeville, province of Namur, and the well-known " Belgian black " from quarries in Golzines, and the environs of Dinant, also in the province of Namur.;}; All of these are very fine grained and compact, admitting of smooth surfaces and high polish. The St. Anne marble is of a deep blue-black color with many short and interrupted veins of white ; those of Couillet are much lighter in color and with more white ; some of the varieties are breccias composed of fragments of compact blue- gray limestone imbedded in a white Crystalline matrix. The red marbles of Cerfontaine and Merlemont are known as rouge griotte, rouge griotte fleure 1 ^ rouge imperial and rouge royal. All * Les marbres, p. 44. f Materiaux de construction, p. 194. \ Violet gives the full list of Belgian marbles as follows: " Le marbre Saint Anne, le rouge royal, le rouge imperial, la griotte de Flandre, le griotte fleuree, le granite beige, le bleu beige, la Florence beige, bizantin beige, bleu antique, le grand antique, le petit antique, et les marbres noirs de Golzinnes et de Dinant." 158 STONES FOR BUILDING AND DECORATION. are dull red, of light and dark shades, variously spotted, fleck- ed, and veined with white and gray ; none of them are as brill- iant in color as the French griottes. The variety rouge royalis very light, and somewhat resembles certain varieties of the Tennessee marbles, but is inferior. The well-known Belgian black is of a deep black color, hard, and difficult to work, but takes a high polish, and is considered the best of its kind now in the market. France : Griotte, or French Red Marble. This beautiful stone takes its name, according to Violet,* from the griotte cherry, owing to its brilliant red color. When, as frequently happens, the uniform redness is broken by small white spots, it is called " bird's-eye griotte " (griotte ceil de perdrix}. Some varieties are traversed by white veins, but these are regarded as defects and are avoided in quarrying. The stone is found in several localities in the French Pyrenees, notably in the valley of the Barousse, of the Pique, at the bridge of the Taoulo, and in the environs of Prades. It is used for all man- ner of interior decorative work in France, and is exported to a very considerable extent to this country. This is by all odds the most brilliant in color of any marble of which the author has knowledge. In the small slabs usually seen in soda foun- tains and counters it appears homogeneous and free from flaws. As displayed in the halls of the capital building at Albany, New York, however, it is full of flaws and has been so extensively " filled " as to give the whole surface a gummy appearance, in striking contrast with that of the Tennessee marble with which it is associated. The price in France as given by Violet is from 400 to 500 francs per cubic metre, or about $2.75 to $3.50 per cubic foot, according to quality. Another marble of a brilliant scarlet color, blotched with white and known as Languedoc marble or French red, is stated * Les Marbres, etc. Rapports sur L'Exposition Universelle, 1878, xxvm. p. 15. STONES FOR BUILDING AND DECORATION. 159 by Violet to occur at various points in the Pyrenees, but in masses of exceptional beauty and compactness at Montague Noire (Black Mountain), where it has been quarried since the sixteenth century. It is obtainable here in blocks of consider- able size, which bring in the market of Carcassone prices vary- ing from 250 to 350 francs per cubic metre, or, roughly speak- ing, from $1.75 to $2.20 per cubic foot. Other French marbles, though which are but little used in this country, are the rose marble from Caunes, the vert-moulin, also called griotte campan, the campan vert, or the campan melange. The wrongly so-called Italian griotte is, according to Chateau, obtained from quarries at La Motte de Felines d'Hautpoul, Department of Herault. Violet states that this name was given it simply that it might command a higher price. Caen stone. This is one of the most noted limestones of modern history. It is a soft, fine-grained stone, very light colored, and admirably adapted for carved work, but so absorb- ent as to be entirely unfitted for outdoor work in such a climate as that of the United States. Egleston* states that in the climate of New York City the stone does not endure longer than ten years unless protected by paint. The stone takes its name from Caen, in Normandy, where the principal quarries are situated. It was probably introduced into Great Britain soon after the Norman conquest, where it was largely used in cathedrals and other buildings down to the middle of the fifteenth century. The cathedral of Canterbury and Westminster Abbey are of this stone. Brocatelle. This is a very beautiful marble and much used for mantels and other interior decorations. The body of the stone is very fine and compact, and of a light yellow color, traversed by irregular veins and blotches of dull red. It is * Transaction American Society of Civil Engineers, XV. 1886. 160 STONES FOR BUILDING AND DECORATION. further variegated by patches or nodules of white crystalline calcite. It takes an excellent polish and requires less filling than many marbles. Its source is stated by Violet to be Jura, in southern France. The stone is difficult of extraction and brings a high price. The name brocatelle is stated by Newberry to signify a coarse kind of brocade used for tapestry. The National collections show a variety of coarsely mottled white, gray and almost black stones of fine grain and susceptible of a high polish, from Scherneck, near St. Die, and from Fra- mont in the Department of Vosges ; also a stone of similar structure but with a chocolate red base from the same locality. A compact black stone thickly studded with small white asterisks is found in the valley of the Hogneau. A coarse conglomerate marble taking a fair surface and polish, and composed of dull pink, yellowish and drab pebbles in a pinkish base, is found in the valley of Tholonet, near Aix, and is known commercially as Breche d* A let. Germany. The two principal marbles now imported from this country are known commercially as Formosa and Bougard. Both are very beautiful stones, ranking among the finest now in general use. The first named is dark gray and white mot- tled and blotched with red ; it is slightly fossiliferous. The Bougard has about the same colors, but is lighter and the tints are more obscure They are said to come from Nassau. Austria. The marbles of Austria stand in strong contrast with those of the United States, in that with few exceptions they have undergone less metamorphism, and are, therefore, of an extremely fine and compact, microcrystalline texture and often highly fossiliferous. Stones of this type of structure and varying from dark chocolate, through creamy white, pink- ish, dull red and yellowish variegated, dark siena yellow or drab, and often beautifully brecciated, occur in the Jurassic STONES FOR BUILDING AMD DECORATION. l6l formations in the vicinity of Castione, in the Tyrol. Drab and white mottled fossiliferous stones are also found in the Lias formations of this same district. Dark chocolate red and variegated, and gray and black highly fossiliferous stones are found near Saltzburg, and also pure white crystalline forms resembling those of Massachusetts and Connecticut. By far the most beautiful of the above are the pink, yellowish, and white brecciated varieties from Castione. Many of these stones are hard and plucky, but can be worked down to a smooth surface and acquire a high polish such as is obtainable only on stones of such dense and compact structure. It is a matter of regret that similar stones are not as yet to be found on the markets of the United States. Chalky white, buff and gray limestones suitable for build- ing and carved work, but which do not polish, are obtained from the Miocene formations of Margarethen, Oszlopp, Man- nersdorfer, Hundsheimer and other towns in Lower Austria. The so-called lumachelle marble is a fossiliferous limestone in which the shells still retain their nacre, or pearly lining, and which when polished gives off in spots a brilliant iridescent lustre with rainbow tints ; the finer varieties being seemingly set with opals. It is a beautiful stone for inlaid work and elaborate ornamentation, but is usually found only in small slabs. A variety quite commonly seen in mineral cabinets is of a dark grayish-brown color and with occasional brilliantly iridescent spots and streaks like those of the fire opal. It is brought from Bleiberg and Hall in the Tyrol. Spain and Portugal. These countries possess a great amount and variety of stone suitable for building and orna- mental work, but, so far as the writer is aware, only a few of the marbles and limestones are exported to this country, and need be referred to here. There is stated to be a zone of crystalline marbles of white, 1 62 STONES FOR BUILDING AND DECORATION. yellow, and flesh color, which extends through the provinces of Estremoz, Borba, and Villa Vic.osa ; a black variety with white veins also occurs at Monte Claros. These are all susceptible of a good polish, and blocks of large size can be obtained. The beds belong to the Laurentian formations. In Vianna, Alrito, Portel, and the mountains of Ficalho other marbles are found of the same general character. The rocks of the Jurassic and Cretaceous formations also furnish a large quan- tity of material for building and ornamental use. This is especially the case at Coimbra, Figueira da Foz, Cintra, and Pero Pinheiro. At Cintra the limestones have been meta- morphosed by the adjoining granites, while those of Pero Pinheiro were likewise metamorphosed by the volcanic rocks of the suburbs of Lisbon.* One of the finest of the above-mentioned marbles, and one which is much used in the United States, is the yellow, from Estremoz. This is known commercially as Lisbon marble. In color and texture it is almost identical with the celebrated Italian Siena, with which it favorably compares. A peculiar stone from this same locality is white with streaks and blotches of a blood-red color. It is more peculiar than beautiful. The marbles of Pero Pinheiro are of mottled white and pink almost red color, fine grained and compact. They are said to have been extensively used in Lisbon, where they have proved very durable. Other marbles that perhaps need especial mention are the breccias from Serra de Arrabida and Chodes, Saragossa Province. The first named is composed of rounded and angular pebbles of a gray, drab, black, and red color, embedded in a dull red paste. In a general way it re- sembles the breccia from Montgomery County, Maryland, but * Portuguese Special Catalogue, Departments, i., n., in. , iv., and v. ; In- ternational Exhibit, 1876, pp. 29, 30. S7VNES FOR BUILDING AND DECORATION. 163 has less beauty. The Chodes stone is composed of very angu- lar fragments, of a black color, in a reddish brown paste. The proportion of paste to the fragments is very large and much filling is necessary in polishing. Fine, compact marbles of dull reddish hues, often veined with drab, occur in Pannella Province. Others that may be mentioned are the red and yellow mottled marbles of Murcia Province, the black of Alicante Province, and the black white-veined breccias of Madrid. A fine translucent alabaster is also included among the productions of Saragossa Province. A very full series of these stones was exhibited at the Cen- tennial Exposition at Philadelphia in 1876, and from there transferred to the National Museum at Washington. Italy. The quarries of the Apennines in northern Italy, near Carrara, Massa, and Serravezza, furnish marbles of a great variety of colors of the finest qualities and in apparently inex- haustible quantities. To give a full description of these quar- ries and their various products would be to transcend the limits of this work. I shall therefore confine myself to a brief description of only those stones which are imported to any extent into this country. White statuary marble. This is a fine grained saccharoidal pure white stone, without specks or flaws. On a polished sur- face it has a peculiar soft, almost waxy appearance, entirely different from the dead whiteness of the Vermont statuary marbles, to which it is considered greatly superior. It is brought principally from the Poggio Silvestro and Betogli quarries, that from the first named locality being considered the best. The price of the stone in Italy varies from 15 to 40 lires per cubic foot in blocks of sufficient size for an ordinary statue 5 feet ifi height. Ordinary white or block marble. This is usually white in color, though sometimes faintly bluish and veined. It is 164 STONES FOR BUILDING AND DECORATION. largely imported into this country, and used for monumental work. The variety from the Canal Bianco quarries is white, with faint bluish lines ; that from Gioja quarries is fine-grained, and uniformly white and somewhat translucent, sometimes resembling gypsum on a polished surface. The variety from the Ravaccione quarries is faintly water-blue, while that from the Tantiscritti quarries is of similar color, but traversed by fine, dark-bluish veins. These stones sell for from 4 to 10 lires per cubic foot, in blocks containing not over 20 cubic feet each. The veined marbles from the Vara and Gioja quarries are of a white color, but often blotched with darker hues, and traversed by a coarse irregular net-work of faintly bluish lines. The Bardiglio marbles of the ordinary type from the Para and Gioja quarries are of a water-blue color, blotched irregularly with white, and far inferior in point of beauty to the justly famed Bardiglio veined marbles from the Seravezza quarries. These are of a light-blue color, traversed by an irregular net- work of fine dark-blue lines, intersecting one another at acute angles. This stone is used very extensively in soda-water fountains, counters, and for panellings. The red mixed marble from quarries at Levante is also much sought, but works with difficulty and requires much fill- ing. It is properly a breccia, composed of irregular whitish and red fragments embedded in a reddish paste. It does not take a high polish, nor are its colors brilliant. The so-called Pannazo marbles, from the Miseglia, Pescina, and Bocca del Frobbi quarries, are all white or whitish, and traversed by a very coarse net-work of black or blue-black veins. The yellow or Siena marbles are, next to the white statuary, probably the most sought and widely known of Italian marbles. Like the majority of foreign colored marbles, they are exceed- ingly fine-grained and compact in texture, and take a high lustrous polish. The prevailing color is bright yellow, though STONES FOR BUILDING AND DECORATION. 165 often blotched with slight purplish or violet shades. When these darker veins or blotches prevail to a considerable extent the stone is called Brocatelle. The most beautiful variety of the Siena marble is obtained, according to Delesse, from Monte Arenti, in Montagnola. It is of a uniform yellow color, but blocks of large size can be obtained only rarely, and these often bring a price as high as $6 per cubic foot. The Broca- telle variety from the same locality is worth only about two- thirds this sum. The Portor or black and gold marble. This is, according to Delesse, a black silicious limestone, traversed by yellowish, reddish, or brown veins of carbonate of iron. It is brought chiefly from the Isle of Palmaria, in the Gulf of Spezia, and from Porto Venere. A small amount is also produced at Carrara and Serravezza. Blocks of this stone in the National Museum show a good surface and high polish. It is a beauti- ful stone, and the name black and gold well describes it. The Portor marble, from the Monte d'Arma quarries, is a breccia of fragments of black limestone with a yellowish cement. This is inclined to break away in the process of dressing, thus rendering the production of a perfect surface impossible with- out much filling. Black marble. A fair variety of this material is brought from the Colonnata quarries. The stone is not as dark as the Belgian black, nor does it admit of so high a polish. Breccia marble. The breccia marbles from Gragnana and Serravezza I have never seen in use in this country, though they are stated to be imported to a slight extent. The first- named consists of small bluish-white fragments cemented closely by a chalk-red cement, while the second variety has both white and red fragments similarly cemented. The yellow marbles of Verona and Gragnana are quite dif- ferent in appearance from those of Siena, being rather of a 166 STONES FOR BUILDING AND DECORATION. brownish hue, and taking only a dull polish. They are com- pact rocks, excellently adapted for decorative work. The so called red marble from the Castel Poggio quarries is rather a chocolate color, dull in polish, but pleasing to the eye. Ruin marble. This is a very compact yellowish or drab limestone, the beds of which appear to have been fractured in every conceivable direction by geological agencies, after which the resultant fragments have become recemented by a calcare- ous or ferruginous cement. The rock is therefore really a breccia, although the proportional amount of cement is very small, and the actual displacement of the various particles but slight. When cut and polished the slabs have somewhat the appearance of mosaics, representing the ruins of ancient castles or other structures. Hence the name of " ruin marble." The locality as given by Delesse, is the bridge of Rignano, Val de Sieve, in the environs of Florence, Italy. Greece. The celebrated Parian marble of the ancients was brought from Pares, a small island of the Grecian Archipelago. It is stated * that the southern part only of the island consists of crystalline limestone, the pure white statuary marble form- ing beds of from five to fifteen feet in thickness intercalated with other layers of coarser texture and traversed by dark veins, the coloring matter being oxides of iron and manganese. It is further stated that the marble beds are much disturbed and folded, and often dip at high angles. The ancients avoided the stone lying near the axis of this elevation, as being of poorer quality than that in other parts. A recently formed Greek company instead of profiting by this experience attempted quarrying in these parts, but the poor character of the material obtained soon discredited the marble in the mar- ket, and the company failed as a consequence after expending some $800,000 in their plant. * Robert Swan in Repori British Association, Sept., 1889. STONES FOR BUILDING AND DECORATION. 1 67 SOME MINOR ORNAMENTAL STONES. It may be well to mention here, briefly, a few of the rarer stones used for ornamental purposes, particularly for inlaid and finely decorative work. Such stones as are used merely as gems will not be included, since they are sufficiently well de- scribed in other available treastises. (See bibliography, p. 428). Agahnatolite. This is a somewhat general name given to a not well defined class of rocks of varying composition but having in common a fine compact texture free from grit, a ser- pentinous or talcose look and feel, and which owing to their physical rather than chemical properties are readily carved into a variety of forms. The more important substances here in- cluded are the minerals pyrophyllite and pinite. The first is an aluminous bisilicate of the composition, silica 64.82$, alum- ina 24.48, water 5.25$, with traces of iron, magnesia and lime. A nearly white schistose rock of this nature occurs in the Deep River region, and at Carbonton, Moore County, North Caro- lina, but is utilized only as a white earth and for slate pencils. Near Washington in Wilkes County, Georgia, is a deep lus- trous green and white variety of the same mineral, and which though soft could be used advantageously in certain forms of ornamentation. On a polished surface the stone shows a gray groundmass mottled with irregular streaks and blotches of pea green and occasional shreds of silvery white mica. Pinite is, according to Dana, a hydrous alkaline silicate, con- taining silica 46$, alumina 30$, potash io#, water 6$. Rocks of this general class are much used in China, Corea and Japan for making a variety of objects including ornamental dishes, miniature pagodas, and grotesque images. The name agal- matolite, according to the the above authority, being from the Greek ayaXpa, an image, and pagodite from pagoda, on 1 68 STONES FOR BUILDING AND DECORATION. account of the use to which the stone is put. A common color of the Chinese rock is faint greenish mottled with red. A sim- ilar stone from the State of Sonora, Mexico, is exhibited in the collections of the National Museum, but there are no records to show that it has here ever been put to any use. Cat Unite, or Indian Pipestone. Although frequently found in the collections of amateur mineralogists this substance can- not be considered a true mineral, but as shown by analyses is rather an indurated clay of quite variable composition. The usual color is a deep though dull red, often beautifully flecked with small yellowish dots. The stone is soft enough to be readily cut with a knife, but is sufficiently firm and compact to retain the sharpest edges and lines that may be carved upon it. There is, in fact, an entire absence of granulation and its texture is as fine and close as that of the Bavarian lithographic stone. The material first derived its notoriety from the fact that the Sioux Indians utilized it for the manufacture of their pipes and various other articles, and at the present time these same people living in the vicinity of Flandreau, Dakota, derive a considerable income from the manufacture and sale of these articles. The substance is found in various places in Minne- sota and Wisconsin, but the principal quarry, if such it can be called, is situated a little north of what is now Pipestone City, in Pipestone County, Minnesota. The country is low prairie land, and the stone occurs as a layer of only about eighteen inches thickness, interstratified with a hard, tough quartzite. It can therefore be obtained in pieces of only very moderate dimensions, and this too at a very considerable outlay of time and labor.* The color and textural qualities of the stone are such that *See Geology of Minnesota, vol. n. ; also American Journal Science, 1867, p. 15, and American Naturalist, 1868-69. STONES FOR BUILDING AND DECORATION. 169 it might, in proper combinations, be used to excellent advan- tage in interior decorative work. On the Sweetwater branch of the Ruby River south-west From Virginia City, in Madison County, Montana, there occurs a peculiar rock, in many respects similar to that just described. Whatever may have been the origin of the rock it now has the aspect of an indurated clay. Its prevailing colors are gray, drab, yellow and red sometimes pinkish, or bluish, the colors being always arranged in concentric zones varying from the dimensions of a mere line to an inch or more in width. The rock occurs only in small jointed blocks, and the zonal banding is in all cases approximately parallel to the outline of the blocks, being a product of the oxidation of the ferruginous constituent of the rock. In texture the rock is as smooth, fine and homogeneous as is the catlinite above described. It hence is susceptible of a fine surface and good polish. In proper combination the stone could be used to good advantage for interior decorations. At present the nearest railroad shipping point is at Dillon some twenty-five miles away. Fossil Coral. The masses of fossil acervularia from the Devonian limestones of Iowa furnish very beautiful material for small ornaments, as already described on p. 92. Labradorite. The name Labradorite is given to a mineral belonging to the feldspar group, and which owes its claims to recognition as an ornamental stone to a beautiful and sometimes actually gorgeous iridescence in every shade of blue, green and yellow. The stone is of a gray color, quite hard, and as a rule the iridescent portions occur only in small areas. As moreover the polished surface needs be turned at various angles with the light in order to bring out its full beauty, it is not well suited for stationary objects, but 1 70 STONES FOR BUILDING AND DECORATION. rather for vases and other small ornaments. The present sup- ply comes mainly from Labrador and Russia. It is the pres- ence of this feldspar that gives rise to the bluish iridesence sometimes seen on the so-called Au Sable granite, quarried at 1 Keeseville, New York. Lapis-Lazuli. This is a hard, tough and compact rock of a rich, azure-blue color, and vitreous lustre. It is not a homo- geneous mineral, but an intimate mixture of granular calcite, ekebergite and a blue mineral, the exact chemical nature of which has not been fully made out. The chemical composi- tion, as given by Dana, shows it to be composed mainly of silica and alumina, with smaller percentages of lime, soda, iron, and sulphur. The stone is much esteemed for highly ornamental inlaid work, but is very expensive, so that as a rule it is used only in the form of a thin veneering. The stone occurs in granular limestone and syenitic rocks according to Dana. The commercial supply is brought from Persia, Siberia and China. Malachite and Azurite. These are the names given to the green and blue carbonates of copper, and which occur at times in sufficient abundance and compactness of texture to permit of their being utilized for table tops, vases and other small ornaments. Both forms of the carbonate are common as ores of copper, though it is but rarely that they occur in such abundance as to be of value for decorative purposes. The most noted source of malachite is Nijni Tagilsk, in the Russian Urals. The mineral occurs in stalagmitic masses of a beautiful banded structure and of various shades of green. Solid blocks of a cubic yard in dimensions are stated to have been obtained here. Another source is the Burra Burra Mine, near Adelaide, Australia. Smaller masses have been found in the copper mines of Arizona. STONES FOR 3UILDING AND DECORATION. I /I The deep azure blue carbonate azurite is less common than malachite. It occurs not infrequently interbanded with the latter in stalagmitic masses, which show, therefore, beautiful blue and green concentric bands when cut across. Nephrite, or Jade. The name nephrite, or jade, has been given by mineralogists to a very compact and tough, light greenish to whitish mineral of the amphibole group, and which has been used for making cutting-implements and ornaments by numerous widely-scattered barbarous or semi-barbarous nations. The attention of scientists was first drawn to the sub- stance by the finding of implements of it, not only among the tribes still living, but among prehistoric ruins, such as the Swiss lake dwellings. The constant recurrence of objects of this nature among perhaps widely separated tribes was a very striking fact, and it was thought at one time that this might indicate a means of inter-tribal intercourse, or trade, or even perhaps a common origin, since it at first seemed scarcely probable that a stone so difficult to work and of so similar an appearance should be found and utilized for similar purposes the world over. This idea has, however, been now shown to be fallacious. It is, however, none the less interesting a fact that the mineral occurs in comparative rarity among so many nations, and that moreover it should have quite independently been in all cases adopted for similar purposes. The localities from whence objects of nephrite have from time to time been reported by collectors, are as follows: Brittany, Switzerland, Silesia, New Zealand, New Caledonia, China, Turkestan, Siberia and Alaska. The finding of nephrite objects, as knives, beads, etc., 'among natives of the last-named place, after it was known to occur in Siberia, gave rise to the erroneous supposition that there was tribal communication between the two localities. Within a few years, however, various United States exploring 172 STONES FOR BUILDING AND DECORATION. parties have brought in samples of the rough jade found in situ in Alaska, proving again the oft-proved fact that as a means of tracing migration or communication, the occurrence of the substance is of no value. The Chinese seem to have been the great masters in work- ing this refractory material, and their delicate carvings of jade are famous the world over, and sometimes bring almost fabu- lous prices among collectors. A thousand dollars for a finely carved vase or ornament, perhaps but a few inches in length, is, as I am informed, no uncommon figure. It is stated that in the Indian museum, in London, there is a beautiful white jade object which it required three generations of jade workers eighty-five years to complete. As with many other stones, jade or nephrite was once believed to possess medicinal virtue, and its name, nephrite, is from the Greek word nephros, signi- fying kidney, in allusion to its supposed efficacy in diseases of these organs. It is stated that jade was in use among the Chinese fully 2,737 years before Christ, or more than 4,600 years ago. Obsidian. The possibilities of this rock will be mentioned under the head of liparites, and it need not be further described here. Pegmatite Graphic Granite. This a granitic rock consist- ing mainly of quartz and orthoclase, but in which the constitu- ents instead of crystallizing in the usual granular condition are in the form of long parallel and imperfect prisms as will be later noted, so that a cross section shows the clear glassy quartz rudely imitative of letters of the ancient Grecian or Phoenician alphabet, set mosaic-like in a groundmass of white orthoclase. The prevailing color is nearly white, the stone is hard and can be worked only in comparatively small pieces. Quartz. The various forms of silica, known as quartz STONES FOR BUILDING AND DECORATION. 1 73 agate, jasper, etc., are almost too well known to merit special mention. The ordinary limpid quartz and the amethystine variety is used in the cheaper forms of jewelry and is carved into beau- tiful images or polished spheres by the Japanese, but it is not used for large ornamentation. The name jasper is given to an impure crypto-crystalline variety colored, blotched and streaked with shades of red, brown and yellow by iron oxides. The heliotrope or bloodstone, a green jasper blotched with blood red, is one of the most prized varieties. The name agate is given to the banded nodular masses of chalcedony that form in the cavities of trap rock or sometimes replace the organic matter in fossil wood. Nearly all agates as sold are colored artificially by first boiling them in honey or an organic oil and then heating them, whereby the carbonaceous matter absorbed unequally by the various layers is turned various shades of brown and black, thereby rendering more conspicuous the banding. Wood is not infrequently fossilized by silica, the organic matter being replaced atom by atom by the siliceous matter until a more or less complete cast of the woody structure remains. Such are often variously colored, mainly in red tints by iron oxides and when cut and polished are very beautiful. In the so-called fossil forest near Corriza, Apache County, Arizona, have been found many tree trunks thus fossilized, which, when cut and polished, have furnished small columns and tops for stands, of exceptional beauty. The great toughness of the material renders it very expen- sive to work. Rhodochrosite. This mineral is chemically a carbonate of manganese. Its claim as an ornamental stone lies in its com- pact texture and delicate pink color. Unfortunately it has never been found in uniform masses of large size; and as, more- over, it is stated to fade slightly on exposure to strong light, 1/4 STONES FOR BUILDING AND DECORATION. its utility is perhaps doubtful. It occurs commonly in veins along with ores of gold, silver and copper. Fine massive blocks are taken out of the silver and copper mines at Butte, Montana. Rhodonite. This is a silicate of manganese of a red or pink color and frequently more or less streaked and spotted. It is hard and tough, with a close texture, and admits of a high polish. It has been as yet but little used, the main supply being brought from the Urals of Siberia. Boulders of the material have frequently been found at Cunningham, Massachusetts, and it has been stated * that the parent ledge is also now known. As the mineral here is of exceptionally fine color, there is, perhaps, a prospect that it may become of some com- mercial value. Like rhodochrosite it is stated to change color on pro- longed exposure. Thulite stone. The name thulite is given to a red man- ganese epidote, and hence the name thulite stone to a rock in which this mineral is the essential constituent. So far as the author is aware rocks of this nature have as yet been found in any abundance only in Norway, at Hinderheim about 21 kilometers north of Trondhjem, on the north side of the Trondhjemfjord. As above noted the essential constituent is thulite ; there is also a little quartz, piedmontite, and common epidote. The texture is finely granular and the color a pleasing rose red. It has as yet been little used, owing to the difficulty of obtaining large blocks of uniform color, its brittle nature, and the difficulty of polishing. The rock is described as occurring in sporadic areas, rarely more than 5 or 6 feet across, in a granitic gneiss.f * Mineral Resources of the United States. 1887. f H. Reusch. Geologtske lagttageleer Fra Trondhjems Stifft. 1890. STONES FOR BUILDING AND DECORATION. THE GRANITES AND GNEISSES. (l) COMPOSITION AND GENERAL PROPERTIES. Granite from the Latin granum, a grain, in allusion to the granular structure. The essential constituents of granite are quartz and a potash feldspar (either orthoclase or microcline) and plagioclase. Nearly always one or more minerals of the mica, hornblende or pyroxene group are present, and in small, usually microscopic, proportions, the accessories magnetite, apatite, and zircon ; more rarely occur sphene, beryl, tourmaline, topaz, garnet epidote, allanite, fluorite and pyrite. Delesse* has made the following determination of the relative proportion of the prin- cipal constituents in two well-known granites. RED EGYPTIAN GRANITE PORPHYRITIC GRANITE, VOSGES. Red orthoclase 43% White orthoclase 28^ White albite 9# Reddish oligoclase 7% Gray quartz 44% Gray quartz 59$ Black Mica 4% Mica 6% 100% 100% The average chemical composition is as follows : Per cent. Silica 72-00 Alumina * 15.07 Iron peroxide 2.22 Magnesia 5-o Lime 2.00 Potash 4-12 Soda 2.90 Loss by ignition 1.19 * Prestwich Chemical and Physical Geology, vol. i. p 42. 1/ STONES FOR BUILDING AND DECORATION. The average specific gravity of granite is 2.66, which is equal to a weight of l66|- pounds per cubic foot, or practically 2 tons per cubic yard. According to Professor Ansted* granites ordinarily contain about 0.8 per cent, of water, and are capable of absorbing some 0.2 per cent. more. In other words, a cubic yard would in its ordinary state contain 3.5 gal- lons of water. The crushing strength of granite is quite vari- able, but usually lies between 15,000 and 20,000 pounds per square inch, as will be seen by reference to the tables. Structurally the granites are holocrystalline granular rocks without trace of amorphous interstitial matter. As a rule none of the essential constituents show perfect crystal outlines, though the feldspathic minerals are often quite perfectly formed. The quartz has in all cases been the last mineral to solidify, and hence occurs only as irregular granules occupying the interspaces of the other minerals. It appears always fresh and glassy, but on microscopic examination is found to contain numerous inclosures, such as rutile needles and little prisms of apatite. A most interesting fact is the presence of minute cavities within the quartz, usually filled wholly or in part with a liquid, though sometimes empty. This liquid is commonly water containing various salts, as the chloride of sodium or potassium, which at times separates out in the form of minute crystals. Carbonic acid is frequently present, giving rise to a minute bubble like that of a spirit-level, and which moves from side to side of its small chamber as though endowed with life, So minute are these cavities that it has been estimated from one to ten thousand millions could be contained in a single cubic inch of space.f The rocks vary in texture almost in- definitely, presenting all gradations from fine and evenly granu- * Hull, Building and Ornamental Stones, p. 30. f Judd, Volcanoes ; What they are and what they teach, p. 64. STONES FOR BUILDING AND DECORATION. If? lar to coarsely porphyritic forms, in which the feldspars, which are the only constituents porphyritically developed, are several inches in length. The prevailing color is some shade of gray, though greenish, yellowish, pink and deep red are not uncommon. The various hues are due to the color of the pre- vailing feldspar and the abundance and kind of the accessory minerals. Granites in which muscovite is the prevailing mica are nearly always very light gray in color : the dark gray colors are due largely to abundant black mica or hornblende : the greenish, pink or red colors to the prevailing greenish, pink or red feldspars. The varying effects of the predominating con- stituents upon the physical and enduring qualities of the stone have already been referred to under the head of rock-forming minerals and need not be repeated here. Gneiss differs from granite in that its various constituents are arranged in more or less paralled layers, giving the rock a banded or schistose structure and causing it to split in a direc- tion paralled with the bands much more readily than across them. Chemically and from a mineral standpoint the rock is identical with granite and is used so far as these structural peculiarities will allow for the same purposes. It is therefore in the following pages included with the granites. The word gneiss, it should be stated, is of German origin and pronounced as is our word nice, not as though spelled nees. These rocks are often called stratified or bastard granites by the quarrymen. (2) GEOLOGICAL AGE AND MODE OF OCCURRENCE. The granites are massive rocks, occuring most frequently associated with the older and lower rocks of the earth's crust, sometimes interstratified with metamorphic rocks or forming the central portions of mountain chains. They are not, as 178 STONES FOR BUILDING AND DECORATION. once supposed, the oldest of rocks, but occur frequently in eruptive masses or bosses invading rocks of all ages up to late Mesozoic or Tertiary times. Thus Professor Whitney consid- ers the eruptive granites of the Sierra Nevada to be Jurassic. Zirkel divides the granites described in the reports of the 4Oth Parallel Survey into three groups ; (i) Those of Jurassic age ; (2) those of Paleozoic age, and (3) those of Archaean age. The granites of the eastern United States, on the other hand, have, in times past, been regarded as mainly Archaean, though Dr. Wadsworth* has shown that the Quincy, Massachusetts, stone is an eruptive rock of late Primordial or more recent age, while Professor Hitchcock regards the eruptive granites of Vermont as having been protruded during Silurian or perhaps Devonian times. (3) VARIETIES OF GRANITE. In classifying granites the varietal distinction is based upon the prevailing accessory minerals. The more common varie- ties are muscovite granite, biotite granite, muscovite-biotite gran- ite, hornblende granite and hornblende-biotite granite ; more rarely occur augite, epidote, tourmaline, cordierite, and chlorite granites. The variety without any accessory minerals is some- times called granitell. Protogine is the name given to granites which have talc or chlorite as the characterizing accessory. Pegmatite or graphic granite is a vein rock containing little if any mica, but consisting nearly altogether of quartz and ortho- clase. It owes its peculiar structure to the crystallization of these two constituents in long parallel and imperfect prisms, so that a cross-section shows peculiar triangular and polygonal figures comparable to the letters of the ancient Greek or Phoe- nician alphabets. * Proceedings Boston Society of National History, xxi. 1881. STONES FOR BUILDING AND DECORATION. Aplit is a name used by the Germans for a granite quite poor in mica, and consisting essentially of quartz and feldspar only. The name greisen is applied to a quartz-mica rock with accessory topaz occurring associated with the tin ores of Sax- ony, and regarded as a granite metamorphosed by exhalations of fluoric aci-d. Luxullianite and Trowlesworthite are tourma- line-fluorite granites occurring at Luxullian and Trowlesworth in Cornwall, England. By far the larger proportion of the granites at present quarried in the United States have mica, either muscovite or biotite, as the characterizing accessory, and hence can be spoken of as mica granites. (4) USES OF GRANITE. Owing to their great hardness granites have, until within a few years, been used only in the more massive forms of archi- tecture. It is true that in past ages the cheapness of human life and labor in great part counterbalanced this difficulty, and that Egyptian civilization has left a profusion of temples, obelisks, pyramids and statues with surfaces or interiors often carved and polished in the finest and most delicate manner. With the present high valuation set upon labor such work could never be executed but by the aid of improved machinery and methods of workmanship.* It is perhaps only within the last dozen or possibly twenty years that granite has begun to be considered an ornamental stone. Buildings antedating this are massive, and in only too many instances sombre and unpleasing. One's attention need, * Granite came into early use for building purposes in America probably more on account of its ready accessibility than from any desire on the part of the people for so refractory a material, the matter of transportation then, as now, being an important item in deciding what material was to be used. ISO STONES FOR BUILDING AND DECORATION. however, but be called to the highly ornate character of the State, War and Navy Department building in Washington, the polished granite stairways and pilasters in the new City Hall in Philadelphia, and the thousands of granite tombstones and monuments in our cemeteries to be convinced that the stone not merely possesses all the requisite qualities of an orna- mental stone, but that its use as such is also eminently prac- ticable. There are, indeed, few stones fitted by nature for so wide an application. - Ranging in colors from nearly white to dark gray, from the most delicate pink to deep red, from fine and evenly granular to coarsely porphyritic, the stone more nearly meets the universal need than any other that can be mentioned. It has well been called the noblest of rocks. (5) GRANITES OF THE VARIOUS STATES AND TERRITORIES. California. It is stated that the first stone house erected in San Francisco was built of stone brought from China, and at the present day the granites most employed are brought from Scotland and the Eastern United States. However this may be, it is obvious that this condition of affairs need not long continue to exist, since granites of good quality occur in inex- haustible quantity in the near vicinity. As early as 1853 a granite quarry was opened in Sacramento County, and since then others have been opened and systematically worked in Penrhyn and Rocklin in Placer County. The Penrhyn works are some 28 miles east from Sacramento on the line of the Central Pacific Railroad. The first quarries were opened in 1864, and are now said to cover some 680 acres at Penrhyn and Rocklin,* the latter point being some 6 or 8 miles distant from the former in a westerly direction. """Samples of stone said to be from Rocklin, and which the writer has examined, are rather quartz diorites than true granites. STONES FOR BUILDING AND DECORATION. l8l The rock varies in color from light to dark gray, one variety, which contains both hornblende and biotite, being almost black on a polished surface. They are, as a rule, fine grained, and take a good polish. Blocks more than 100 feet long, 50 feet wide, and ten feet thick have been quarried out and afterwards broken up. The Penrhyn stone is designated a hornblende granitite by Jackson,* who gives its mineral composition as quartz, orthoclase, plagioclase, hornblende, and biotite, with micro- scopic apatite and magnetite. Submitted by the above authority to the action of a carbonic acid gas solution, a sample "of this stone lost 0.05 per cent in weight ; by disintegration in acid fumes it lost 1.09 per cent. In this latter treatment every mica scale on* the surface of the exposed fragments bleached to a pearly whiteness. The iron was dissolved out, staining the rock slightly, while the feldspar grains became a trifle duller in lustre. On being heated in a muffle to some- what above a bright redness, the stone developed a complete network of deep-seated cracks, and after emersion in water could be readily crushed to powder in the hands. The Rocklin stone is described by the same authority as a fine-grained white stone, carrying abundant small scales of black mica and occasional granules of pyrite. The composi- tion is given as essentially the same as the Penrhyn stone, but that muscovite replaces the hornblende. Submitted to the same tests as above the stone lost in the carbonic acid gas solu- tion o.i per cent; and by decomposition and disintegration in the strong acid fumes 0.68 per cent. In this, as in the last case,, mica scales bleached white, and the rock became slightly stained. Heated in the muffle the stone behaved like the Penrhyn granite, though not cracking quite so deeply ; it, * Eighth Annual Report State Mineralogist of California. 1888. 182 STONES FOR BUIIJDING AND DECORATION. however, could be readily crushed to powder after immersion. Reports on crushing strength and ratio of absorption of these stones, and also that of a very similar granite from Mount Ray- mond is Fresno County are given in the table, on p. 404. A fine quarry of granite is stated to occur some eight miles north- east of Sonora in Tuolumne County. A fine-grained, very light-gray granite of excellent appear- ance, said to be found on the line of the California Southern Railroad between Los Angeles and Cucamonga, is beginning to be used in Los Angeles. In texture it is as fine as the finest Westerly, (Rhode Island), or Manchester (Virginia) stone, and of a uniform light gray color. A coarser stone, carrying abundant hornblende and black mica, is found also at Sawpit Canon, in the same county. It works readily, but contains too much hornblende, and also too many small crystals of sphene, to be of value for fine monumental work. Colorado. Until within a comparatively recent period granites have been but little worked in Colorado, although the State contains great quantities of this material. A coarse red granite has been quarried to some extent from bowlders at Platte Cafton, Jefferson County, but the rock is poor in color and possesses but little tenacity. Fine gray granite of good quality occurs at Georgetown and Lawson, in Clear Creek County, and there are inexhaustible quantities of equally good material all through the mountains, but which are not quarried owing to the cost of transportation. Connecticut. Extensive quarries of granite and gneiss are located at various points in this State, especially near Thom- aston and Roxbury, in Litchfield County ; on Long Island Sound, Fairfield County ; near Ansonia, Bradford, and Stony Creek, New Haven County ; Haddam, Middlesex County, and near Lyme, Niantic, Groton, and Mason's Island, New London County. The Connecticut granites and gneisses are usually STONES FOR BUILDING AND DECORATION. 183 fine-grained and light gray in color, and the appearance is, as a rule, so characteristic as to distinguish them from other gran- ites of the Atlantic States. The most of these stones are, however, quarried only for local use, and but few find their way into markets outside of the State. A beautiful light gray muscovite-biotite granite is quar- ried at Thomaston and Reynolds Bridge, which for evenness of grain and clearness of color cannot be excelled. The stone from Roxbury is a trifle darker, but though of fine and even grain and acquiring a good polish, is used only for curbings, founda- tions, and pavings. The Ansonia rock is a very fine-grained muscovite-biotite gneiss, and has been used for general build- ing purposes in New Haven and Bridgeport. The Leetes Island and Stoney Creek rocks are of a pink color, the first mentioned being sometimes very coarsely porphyritic. A turned column of the Leetes Island rock in the National Mus- eum shows large pink orthoclase crystals two inches or more in length embedded in the finer gray groundmass of the rock. A beautiful and very coarsely crystalline red granite occurs near Lyme, but the stone is not in the market, being too ex- pensive to work. It has been used to some extent in Newport, Rhode Island, and some of the material may be seen in the Chaney Memorial Church at this place. Contrary to the gene- ral rule in red granites, the feldspars of this rock are not opaque but quite clear and transparent, and in point of beauty the rock far excels the celebrated Scotch granites from Peter- head. The Haddam, Greenwich, and Bridgeport gneisses are all hornblendic, very dark gray, and split readily in the direc- tion of their lamination ; their uses are strictly local. Delaware. This State produces scarcely anything in the way of granitic rocks. A few quarries of a dark gray gneissoid rock are worked near Wilmington, and are used for general 1 84 STONES FOR BUILDING AND DECORATION. building purposes in this city. One church and several private dwellings have been constructed of this stone. Georgia. Although this State is known to contain inex- haustible quantities of building stones of the finest quality, but little systematic quarrying is done, and none of the rocks have more than a local reputation. A fine grade of muscovite gran- ite, light gray in color, occurs, at Stone Mountain, near Atlan- ta, and also a dark gray hornblendic gneiss. A hornblendic granite resembling that of Quincy, Massachusetts, is said to occur in Oglethorpe County, though the author has never seen any of the material. Maine. The large extent of coast-line of the State of Maine, composed of granitic rocks of a kind suitable for build- ing purposes, renders possible the shipment and transportation of the quarried rock at rates much lower than would otherwise be attainable, the quarries being frequently situated so near the water's edge that little, if any, handling is necessary prior to loading upon the vessel. This favorable circumstance, to- gether with the excellent quality of the rock obtainable, led to the early opening of very numerous quarries both on the main- land and the adjacent islands, and hence at the present time Maine granites are found in very general use in nearly every city of importance in the country, even as far west as Califor- nia, and frequently to the almost entire exclusion of perhaps equally good material close at hand. The granitic areas of the State are outlined as follows by Prof. Hitchcock:* First is the Katahdin area, exclusively in the forest region. This is generally a fine grained rock, that on Mount Katahdin is tabular, and the sheets have a dip like sedimentary strata. The summit rock is red, capping a white variety of granite. The divisional planes seem, however, to be Geology of Northern New England. STONES FOR BUILDING AND DECORATION. 185 joints. Neither this nor any of the granite areas appear like gneiss, though patches of gneiss may occasionally be seen close at hand. Between Penobscot Bay and Schoodic Lake (in Wash- ington County) there is probably a continuous band of granite, which extends through New Brunswick northeasterly a distance of two hundred and ninety miles, and a width varying from ten to twenty miles. Between Elsworth and Holden, eleven miles, this range is porphyritic. In Topsfield, Washington County, it is hornblendic. Protogene (chlorite granite) composes green mountain in Eden, on Mt. Desert. Elsewhere on the island, there is common granite, and a red compact variety, with feldspars predominating. This granitic area seems to be connected with the one just described on the west. Another large granite area extends from Jonesport to Calais in Wash- ington County, and thence into New Brunswick. According to the returns furnished by the special agents in the employ of the building-stone department of the Tenth Census, there were during the census year some eighty-three quarries of various kinds of building stone in the State, situ- ated chiefly either immediately on the coast or within easy reach of tide-water. Of these eighty-three quarries seventy- four were of granite or gneiss. The different varieties of these stones produced may be classed under the following heads : Biotite granite, biotite-muscovite granite, hornblende granite, hornblende-biotite granite, biotite gneiss, and biotite-muscovite gneiss. The great majority of the stones now quarried belong to the first-named variety. They vary in color usually from light to dark gray, though pinkish and red varieties are quar- ried in a few instances. At Red Beach, near Calais, and at Jonesborough there is quarried a pink or reddish rock, very compact and hard, which from a simple examination with the unaided eye is seen to be composed of pink or cream-colored feldspars, smoky quartz, and a few small shreds of mica. An 1 86 STOJVJSS FOR BUILDING AND DECORATION. examination of a thin section with' the mjcroscope does not greatly increase the number of constituent minerals. The mica, which is usually of a greenish color, is very evenly dis- seminated throughout the rock and in very small shreds, bear- ing numerous inclosures of magnetite. A few small apatite crystals are as usual present, but are visible only with a micro- scope. The evenness of the grain of these rocks, and the occurrence of the mica only in small amount and in minute flakes are mat- ters of great practical importance, since they allow the produc- tion of a more perfect surface and lasting polish than would otherwise be possible. The texture is much finer than is that of the red Scotch granite, and the color a more delicate pink. They are, in fact, the most beautiful of any of our pink or red granites now in the market, and are used very extensively for monuments, ornamental work, and general building purposes. The largest blocks ever taken out from these quarries was 7 by 7 feet and 2 feet thick. It is said, however, that blocks 30 by 15 by 2^- feet could be obtained if desired. The principal mar- kets of the stone are Boston, Providence, New York City, Bal- timore, Philadelphia, Buffalo, Cincinnati, Cleveland, and Colum- bus, Ohio, Springfield and Chicago, Illinois, Milwaukee, St. Louis, Charleston, South Carolina, Washington, D. C., and San Francisco, California. At West Sullivan, in Hancock County, a light gray, some- times slightly pinkish, granite of medium texture is extensively quarried for paving blocks and general building purposes. The stone corresponds closely with that quarried in the town of Franklin. At Somesville, on Somes Sound, near Southv/est Harbor, Mt. Desert, is quarried a granite of rather coase text- ure and of a slightly pinkish tinge, the color being due to the orthoclase which is often present in crystals of such size as to give the work a slight porphyritic structure. This stone was used in the construction of the Brooklyn ap- STONES FOR BUILDING AND DECORATION. l8/ preaches to the East River Bridge, and in the arches and foun- dations of the new bridges in Back Bay Park, Boston. Blocks 150 by 50 by 18 feet have been loosened in the quarry. The position of these quarries is peculiarly good for shipping, as they lie near the head of Somes Sound, along a narrow and very deep fiord, running several miles inland from South- west Harbor, between the mountains. One of the quarries is situated on the side of a hill and at the water's edge. The sheets of stone are very thick in some cases, one being 18 feet in thickness. A coarse dull red, very tough and strong hornblende gran- ite is also quarried on the island at Otter Creek, between Somes Sound and Bar Harbor. The stone is of finer texture than are the red Scotch granites, and more closely resembles the red granites of the Bay of Fundy than any other with which the writer is acquainted. Its value for purely monumental purposes is often lessened by the presence of black patches of finer grain, and which are objectionable either on fine cut or polished surfaces. In the vicinity of East Blue Hill, in this same county, are quarried some of the most beautiful gray granites at present in the market. The rock varies from fine, even-grained gray or slightly pinkish to coarsely porphyritic. A foot cube of this granite in the National collections is composed of a fine even-grained gray groundmass, carrying very many snow-white crystals of orthoclase an inch or more in length. This is one of the most beautiful gray granites for monumental work with which the author is acquainted. Blocks 90 by 80 by 6 feet have been moved out in some of these quarries. Specimens of this granite tested at the Centennial Exposition at Phila- delphia in 1876, showed a crushing strength of 22,000 pounds per square inch. In the quarries the stone lies in sheets from 3 to 10 feet in thickness. A portion of the granite from this 1 88 STONES FOR BUILDING AND DECORATION. region is of a pinkish cast, similar to that of Mt. Desert. On the southern end of Deer Isle, also in Hancock County, and on the smaller islands in the immediate vicinity, are inexhaustible supplies of coarse gray granite, sometimes porphyritic, with pinkish orthoclase crystals from two to three inches in dia- meter. There is not, however, sufficient contrast in color to make the stone desirable for monumental work, and its coarse texture is against it. Much of the rock here closely resembles that of Vinalhaven and Hurricane Island, for either of which it might readily be mistaken. Two varieties of granite are quarried at Mount Waldo, in the town of Frankfort. Both are light-gray rocks, frequently porphyritic with large white orthoclase crystals. Both varie- ties are of the same mineral composition, the difference being simply one of texture, one being quite coarse and somewhat porphyritic, while the other is much finer and of more even texture. The mica occurs in large flakes, which the micros- cope shows to be frequently pierced by small crystals of apatite. A part of the mica is greenish in color and contains a few small grains of epidote. An occasional flake of white mica was noticed in this rock, and there is present the usual sprink- ling of magnetite granules, together with an occasional cube of pyrite. Quarries were opened at Mt. Waldo in 1853, an d single blocks 80 by 40 by 20 feet have been taken out and afterward cut up. It is estimated that blocks 150 by 50 by 12 feet could be obtained if desired. The rock has been used largely in the building of forts on the coast of Maine, but is also used for all purposes, both ornamental and otherwise, to which granite is usually applied, and has been shipped as far South as Mobile and New Orleans. The principal quarry is situated on Mt. Waldo, overlooking the Penobscot River, at an elevation of some 320 feet above high tide. At Vinalhaven or Fox Island, in Penobscot Bay, are the STONES FOR BUILDING AND DECORATION. 189 most extensive quarries at present in operation in this country. Quarries were first opened here about 1850, and the annual product has averaged upwards of 200,000 cubic feet, valued at some $110,000. Upwards of six hundred men are regularly employed at the works, though the number has at times risen as high as one thousand five hundred. The capabilities of the quarries can be best illustrated by stating that during a visit of the writer to these quarries in the summer of 1883 he was shown the remains of a huge block of granite 300 feet long, 20 feet wide, and varying from 6 to 10 feet in thickness, that had been loosened from the quarry in a single piece and after- ward broken up. The largest block ever quarried and dressed was the General Wool monument, now in Troy, New York, which measured, when finished, 60 feet in height by 5^- feet square at the base, or only 6 feet 7 inches shorter than the Egyptian obelisk now in Central Park. In texture the Vinalhaven rock is rather coarse and the general color gray, although the prevailing feldspar is some- times of a light flesh color. Besides biotite, the rock contains small amounts of hornblende and microscopic apatite and zir- con crystals. It takes a good and lasting polish, and is well adapted for all manner of ornamental work and general build- ing purposes. The stone has been used so extensively, all over the country, that to cite special cases seems superfluous. A granite closely resembling that of Vinalhaven is exten- sively quarried at Hurricane Island, some 3 miles distant, in a south-westerly direction, and is used for similar purposes. The structure of the stone here differs in different parts of the quarry. In one portion it lies in comparatively thin sheets, while in another there occur immense masses of solid rock, extending downward for 50 feet without perceptible jointing. A block of 80 tons has been moved, and a mass 80 by 40 by STONES FOR BUILDING AND DECORATION. 25 feet was loosened in the quarry. Natural blocks 500 feet long, 20 feet wide, and 50 feet deep occur. The celebrated quarries on Dix Island, in Knox County, from whence was obtained the granite for the United States Treasury building at Washington, including the monolithic columns, 31^ high by 3 feet in diameter, are at the present writing abandoned. Nearly the whole island has been quarried over, and the large bluffs entirely removed. The rock is rich in quartz, and therefore quite hard, but is a good and safe working stone. It has been very extensively used in New York City, Philadelphia, and Washington, D. C. The granite of Augusta and Hallowell has long been justly celebrated for its beauty and fine working qualities. It is a fine, light-gray rock, the uniformity of texture being often broken by the presence of large white crystals of microcline, which inclose small, rounded grains of quartz. Biotite and muscovite occur in abundance, and in about equal proportions, but in small flakes, the muscovite appearing as silvery-white glistening particles on a broken surface of the rock. The rock is therefore classed as a biotite -muscovite granite. Under the microscope three feldspars are readily distinguished, orthoclase in imperfect crystals and irregular grains, an abundance of plagioclase, and microcline in large plates filled with cavities and inclosures of muscovite and quartz. In the thin sections the quartz inclosures are usually circular in outline and are pierced in every direction by minute thread-like crystals of rutile, in polarized light showing up in strong contrast with the beautiful basket-work structure of the inclosing microcline. All the feldspars are quite fresh and pure. A few apatite crystals are present, together with occasional garnets, which in thin sections are destitute of crystalline form, appearing as rounded or oval nearly colorless bodies traversed by many irregular lines of fracture. They are quite free from impuri- OF THE- THU7ERSITT STONES FOR BUILDING AND DECORATION. IQI ties, though occasionally containing inclosures of biotite. As is usual in muscovite-bearing rocks but little magnetite is present ; in two cases only grains of pyrite were noticed. This is one of the best working of the Maine granites, and is used very extensively, not only for building and monu- ments, but is carved into statues, like marble. The rock is considered a gneiss, by Hitchcock, but showing no signs of stratification in the hand specimen, is classed here as a granite. As illustrative of the great extent of the quarries, it is stated that blocks 200 feet in length, by 40 feet in width and 8 feet in thickness, can be broken out in a single piece if so desired. There is no gap between the sheets, and little or no pyrite to cause discoloration. The sheets, as is usually the case, increase in thickness downward, being about I foot thick at the surface and 10 feet thick at the bottom of the present openings, which are from 50 to 60 feet deep. (See Plate VT.) This stone is in such demand for statuary and monumental work that an Italian designer, who served his apprenticeship in Roman studios, is employed constantly by the company. Many of the workmen are also said to be Italians who worked on marble in Italy, but have learned to cut granite since their arrival in Hallowell. Among the prominent structures and monuments constructed, wholly or in part, of this stone, are the new capitol, Albany, N. Y.; Bank of Northern Liberties, Philadelphia ; State capitol, Augusta, Me.; Emory Block, Portland, Me.; Odd Fellows' Memorial Hall, Equitable Build- ing, and part of the old Quincy Market, Boston ; Ludlow Street Jail, the Tribune Building, and the old Tombs Prison, New York City ; the statues of the Pilgrims' Monument at Plymouth, Mass.; Soldiers' and Sailors' Monuments at Marble- head, Mass., Portsmouth, Ohio, Augusta, Boothbay, and Gar- diner, Me.; Odd Fellows' Monument, Mount Hope, Boston, and the Washington Artillery Monument and Hernandez IQ2 STONES FOR BUILDING AND DECORATION. tomb, New Orleans. The statues on the Pilgrims' Monument are said to be the largest granite figures in America. The standing figure is 38 feet in height, while the four in sitting posture are each fifteen feet in height. A granite quite similar to that described above is also quarried, though less extensively, at North Jay, in Franklin County. Similar rocks but of a gneissoid structure occur in Waldo and Lincoln Counties. Other granites, in many cases fully equal to those above described, occur in various parts of the State, and which can be but briefly noticed for lack of space. Mention may be made of the fine dark-gray biotite granite quarried at Swanville in Waldo County ; the fine and coarse gray stone of St. George and Spruce Head Island, in Knox County ; those from Wayne in Kennebec County ; Canaan and Norridgwock, in Somerset County ; Sebec Lake, in Piscataquis County ; Brunswick and Pownal, in Cumberland County ; Biddeford, South Berwick and Kennebunkport, in York County; and from Bryant's Pond, in Oxford County. Also of the darker gray hornblende mica granites of St. George and of Lincoln, in Penobscot County. The so-called " black granites" of Addison, Vinalhaven and Tenants Harbor are diabases and gabbros, and will be men- tioned in their proper places. (See p 231.) Very many of the biotite granites of this State contain numerous masses or nodules of a darker color and finer text- ure than the rock itself, they frequently appearing as black patches on a polished surface. These are of all sizes up to a foot in diameter. They sometimes occur with sharp, distinct outlines, or again merge gradually into the surrounding rock with no definite line of demarkation. Some of them possess a fine, even texture, while others are rendered slightly porphyri- tic in structure through included crystals of plagioclase of con- siderable size. Under the microscope they are all found to STONES FOR BUILDING AND DECORATION. 193 consist essentially of the same minerals as the rocks in which they occur, although in a more finely crystalline state and dif- ferent proportions ; biotite usually prevails and causes the dark color of the patch. Very many of them, however, are penetrated in every direction by innumerable, minute, color- less, needle-like crystals, an exact determination of which, on account of their small size, is impossible. Many of the in- cluded larger crystals of feldspar, which, so far as observed are always triclinic, have their angles rounded away, and are reduced to mere oval grains. Such nodules are usually re- garded as of concretionary origin.* The finer texture and darker color of these patches render them very conspicuous and in some of the quarries many fine blocks of granite are rendered quite unsuited for finely finished or polished work on account of their abundance. Maryland. The Archaean area of Maryland lies northwest- erly of an extremely sinuous line drawn through Havre de Gras, Baltimore and Washington, D. C. It includes, there- fore, large parts of the counties of Cecil, Harford, Baltimore, Howard, Montgomery, Frederick and Carroll. \, Throughout this area are numerous outcroppings of granitic and gneissic rock of a character suitable for general structural purposes, and in a few instances for monumental work as well. The most noted quarries in the State are situated in Balti- more County, near Woodstock. The rock is a biotite granite, varying from light to dark gray in color, and of about medium texture. It is used extensively for general building purposes * See "On Concretionary Patches and Fragments of other Rocks contained in Granite," by J. A. Phillips, Quarterly Journal of the London Geological Society, vol. xxxvi. 1880, pp. 1-22. Also, "On the Black Nodules in the Maine Granites," by G. P. Merrill. Proceedings U. S . National Museum vol. 6, 1883, p. 137. fG. H. Williams. Johns Hopkins University Circular, vol. VII. No. 65. 1888. IQ4 STONES FOR BUILDING AND DECORATION, and for monumental work in Baltimore, Washington and some of the Western States. At Mount Royal and opposite Ellicott City fine-grained, dark-gray gneiss is quite extensively quarried for general building purposes, curbstones, etc. A part of this rock is beautifully porphyritic through large felds- pars an inch or more in length. A dark-gray gneiss, which is extensively used in Baltimore for rough work, is quarried in the immediate vicinity of the city. At Port Deposit, in Cecil County, a gray biotite gneiss is extensively quarried, and is used chiefly for bridge building, docks, harbor improvement and general building work. It has been used in the construction of Haverford College, Maryland, St. Dominick's Church, Washington, and several churches in the immediate vicinity. Other locations where good quality of granite is exposed, are Gwynn's Falls, in Baltimore County, and 3 miles east of Rockville, in Montgomery County. All of the Maryland granites and gneisses at present quarried have biotite as their chief accessory, are of a gray color and of medium fineness of grain. They appear, how- ever, better adapted for general building than for ornamental work. Massachusetts. As Massachusetts was the earliest settled of the New England States, it is but natural that here the sys- tematic quarrying of granite should first be undertaken. As al- ready noted, granite from the bowlders on the Quincy Commons and from Chelmsford began to be used in and about Boston as early as 1737, but it was not until the early part of the present century that its use became at all general. Indeed, it may be said that it was not until the opening of the quarries at Quincy in 1825 that the granite industry assumed any importance. From this time the use of the stone for general building pur- STONES FOR BUILDING AND DECORATION. 195 poses increased in a marked degree, and the history of granite quarrying in the United States may properly begin with this date. This early opening of quarries at Quincy was due largely to the demand for stone at Charlestown for building the Bunker Hill monument, but the attention of capitalists being thereby called to the extent of the granite ledges in this vi- cinity other works were soon established, and at the present time the two, towns of Quincy and West Quincy contain up- wards of thirty quarries. Altogether these produce not less than 700,000 cubic feet annnally, and give employment to nearly a thousand men. .The Quincy granites are, as a rule, dark blue-gray in color, coarse grained, and hard. A pinkish variety is quarried to a slight extent. They are all hornblende pyroxene granites, and their general appearance so characteristic that once seen they are always easily recognizable wherever met with. As already mentioned, these rocks contain besides hornblende a brittle variety of pyroxene, which makes the production of a perfect surface somewhat difficult. Nevertheless, they are very ex- tensively used both for rough and finished work. The United States custom-houses at Boston, Massachusetts ; Providence, Rhode Island ; Mobile, Alabama ; Savannah, Georgia ; New Or- leans, Louisiana, and San Francisco, California, are of this stone, as are also the new Masonic Temple and Ridgeway Li- brary buildings, in Philadelphia. In Boston alone there are one hundred and sixty-two buildings constructed wholly or in part of this material. Its suitability for interior decorative work cannot be better shown than by reference to the polished stair- ways and pilasters in the new city buildings at Philadelphia. Other very extensive quarries of hornblende-granite are located at Cape Ann, in the town of Gloucester, where it is 196 STONES FOR BUILDING AND DECORATION. stated* that quarrying was commenced as early as 1824 by a Mr. Bates, of Quincy. The largest quarries in the State, and, with the exception of those at Vinalhaven, Maine, the largest works now in operation in the United States, are situated at this place. Like that of Quincy, the rock is hornblendic, though frequently considerable'black mica is present.f The texture is coarse and the color greenish, owing to the orthoclase it con- tains. Some varieties are, however, simply gray. It is a hard, tough rock, eminently durable, and well suited for all manner of general building and ornamental work. The stone has been used in the construction of the post-office and several churches and private buildings in Boston, and the Butler house on Cap- itol Hill at Washington. Other hornblendic granites, somewhat similar in appear- ance, are quarried at Rockport, Peabody, Wyoma, Lynn, and Lynnfield. The Rockport stone is the most important of these, and has been quarried since 1830. In color and texture it is indistinguishable from much of the Gloucester stone, but, if anything, is of a more decided greenish hue. In the quar- ries it is extremely massive, and blocks 100 feet long by 50 feet wide and 16 feet thick have been loosened from the bed in a single piece, while it is estimated a block 200 feet long, 50 feet wide and 20 feet thick could be obtained if desired. The prin- tipal markets are New York, Boston, New Orleans, and Cuba. Several important quarries of coarse biotite granite are worked in this State, but their product is mostly used in the near vicinity. Light pink varieties admirably adapted for rock- faced work occur at Brockton, Milford, and North Easton. The * History of Gloucester, Cape Ann, by J. J. Babson, p. 577. f The black mica of the Gloucester and Rockport granites has been shown by Professors Dana and Cooke to be lepidomelane or annite. (Text-book of Mineralogy, p. 313). STONES FOR BUILDING AND DECORATION. Milford stone is particularly effective when used in this manner, as is well illustrated in the new city hall at Albany, New York, and also in the new railway station at Auburndale, Massachu- setts. At Framingham, Leominster, Fitchburg, Clinton, Fall River, and Freetown are also quarries of coarse gray but ap- parently strong and durable granites of this class. Epidote granite. This is a rare variety of granite in this country, the quarries of Dedham producing all that is now up- on the market. The stone is fine-grained and of a light pink color. Besides epidote, which is visible to the naked eye as small greenish specks, it contains numerous flecks of chlorite, resulting from the alteration of a black mica. The stone works readily and gives very pleasing effects either in polished or rock-face work. It is of this stone that was constructed the new Trinity Church in Boston, and which is considered by good authorities to be, from an architectural standpoint, the finest building in America. Gneiss. A fine-grained very light gray, sometimes pinkish, muscovite gneiss of excellent quality has been quarried more or less for the past thirty-five years near the town of Westford. Other quarries of gneiss are at West Andover, Lawrence, Low- ell, Ayer, several towns in Worcester County, at Becket, North- field, and Monson. Being in most cases distinctly stratified, these gneisses are not adapted to so wide a range of application as the massive granites, but at the same time the ease with which in many cases they can be quarried makes them particularly valuable for foundations, bridge abutments, curbing, paving and rock- faced building. At the Monson quarries, for instance, the rock is divided by a series of joints, approximately parallel to the surface of the hill on which the quarries are situated, into im- mense lenticular sheets from 6 inches to 10 feet in thickness. By taking advantage of these uatural facilities a block was IQ8 STONES FOR BUILDING AND DECORATION. split out in 1869 which measured 3 54 feet in length by n feet in width and 4 feet in thickness. An analysis of the Monson stone from the Flint quarry is given in the tables. As a general rule it may be stated that while the granites and gneisses of Massachusetts are good and safeworking stones they are coarse and with a few prominent exceptions in no way remarkable for their beauty. In the matter of color and text- ure they bear a striking contrast to the fine and even grained stones of her sister States, Connecticut and Rhode Island. Minnesota. According to Professor Winchell more than half the State of Minnesota is underlaid by that general class of rocks the crystalline to which granite belongs. In the northern part of the State there are large exposures of very fine light-colored granites, but being beyond the limits of set- tlements and roads those in the southern and western part, in the country bordering along the Mississippi and Minnesota Rivers, are of more especial interest and importance. These last have been somewhat quarried and the materials can be seen in some of the principal buildings in various parts of the State, as well as in cities beyond the State limits. The first quarry in these rocks in Minnesota was that now owned by Breen & Young, at East St. Cloud, Sherburne County. This was opened in 1868, and the stone first taken out was used in the corners, steps, and trimmings of the United States custom-house and post-office in St. Paul. Three kinds of stone were taken out and used indiscriminately, and all of them may be seen in the building first erected. The variety now more generally used is of a gray color and uniform text- ure. The crystalline grains are rather fine, so that the texture is close. The color, however, is sometimes disturbed by the appearance of greenish spots of the size of butternuts or even as large as 6 inches in diameter, caused by segregations of a green chlorite. " About one-third of the whole rock is made STONES FOR BUILDING AND DECORATION. 1 99 up of quartz, and two-thirds of the remainder of orthoclase. About one-half the remainder is hornblende and the residue is divided between the other minerals, the chlorite predominat- ing." An occasional grain of a triclinic feldspar is present together with magnetite and pyrite in minute crystals.* " The red granite from East St. Cloud is not very different from the foregoing, but the feldspar is mainly flesh red and all the grains are coarser." It also has a higher per cent of silica, a fact that has been discovered practically by the owners, who had given up the general use of it because of its being more costly to work. " ... In the winter of 1874-5 a block weighing ten tons was taken out of the red-granite quarry, about 3 miles west of St. Cloud, for a monument base. ... It was very fine, and greatly resembled the Scotch granite in color, grain, and polish. At the point where this was taken out the granite rises about 20 feet above the general surface and spreads over more than an acre. A similar red granite occurs at Watab (in Benton County), and has furnished several handsome monuments." A light gray granite also occurs here.f At Sauk Rapids, in the same county, there is found a fine- grained gray granite closely resembling the gray variety from East St. Cloud. It has been quite generally used, and is one of the best-known granites in the State. Missouri. Although there are inexhaustible quantities of granite in the northern part of Iron and Madison Counties and * See Geology and Natural History Survey of Minnesota, vol. I. pages 142- 148. f These rocks are designated in Professor Winchell's report above referred to as " Syenites." According to the system of classification now generally adopted, they are rather hornblendic or hornblende-biotite granites, as desig- nated by the author in the census report, p. 90. The name syenite, as already noted, is applied to a quartzless rock (see pp. 42 and 223). 2OO STOA^ES FOR BUILDING AND DECORATION. the southern portion of St. Francois, there are but few quarries of the material systematically worked. At Graniteville, Iron County, and in Syenite, St. Francois County, there occurs a coarse red granite, quite poor in mica, which is now extensively quarried for the St. Louis and Chicago markets. It is somewhat lighter in color than the well-known Scotch granite, but is admirably suited for massive structural purposes, as is well illustrated in the lower stories of the fine business blocks erected during the season of 1886 on Adams street, between Fifth avenue and Franklin, and on the corner of Adams and La Salle streets, in Chicago. The enor- mous blocks of rock-faced granite and large polished columns of this stone as here displayed* would indicate that this is des- tined to be one of the leading granites of this portion of the country. It admits of a high lustrous polish and is coming into use for monumental work. Professor Broadhead statesf that the Archaean granites are exposed to view over an area of over 1 50 square miles in Madison County, with as large an area in St. Francois, a smaller one in Iron County, a few square miles in St. Genivieve, and a limited area in Wayne. The colors are various shades of gray and red. Exposed strata show evidence of continuous weathering through many years. Since opening, the interior beds show favorable characters for durability. At the Knob Lick quarries, St. Francois County, there are three varieties, as to color, red, gray, and red and whitish. Of these the gray * The window-sills in the first of the above-mentioned buildings are rough blocks of granite, each 3 feet square by 17 feet 4 inches in length, and weighing about 10 tons each. The polished columns of the building corner of Adams and La Salle streets are ten in number, each 18 feet high by 4^ feet in diameter, and weighing not far from 18 tons. The largest single block of polished granite yet produced at these works is the Allen monument, in St. Louis, which is 42 feet in height by 4^ feet square at the base. The weight is about 45 tons. f The Building Trades Journal, July, 1888. STONES FOR BUILDING AND DECORATION. 2OI is considered the best. A dark colored but handsome stone is quarried near Piedmont, in Wayne County. A dark grayish- brown porphyritic rock is quarried in the northern part of Madison County, and a similar rock occurs at Fredericktown ; also one of like composition and appearance covers several square miles of Stone mountain in St. Francois County. Gray granite is also found eight miles southwest of Ironton in Iron County, and in the northern part of Madison ; a coarser felds- pathic granite is also found in the northwestern part of this same country. Montana. There is a plenty of good granite within the limits of the State, but for lack of a market scarcely any quar- rying is at present carried on. A cube of a fine-grained light gray biotite granite is in the collections of the National Museum from Lewis and Clark Counties, but so far as the writer is aware the quarry has never been worked to any extent. A coarse hornblende mica granite of a greenish-gray color and somewhat resembling the cele- brated Quincy and Gloucester (Massachusetts) stone forms the country rock in the region of the celebrated silver and copper mines of Butte, and is beginning to be used for purposes of heavy foundation and general building. So far as the writer was able to judge, from the short time he was on the ground, the rock is of excellent quality, but needs to be selected with care, as certain portions, those in proximity to the ore veins, are abundantly charged with pyrite, which oxidizes readily on exposure. New Hampshire. Those of the New Hampshire granites that are best known as building materials belong, according to Prof. Hitchcock,* to what is called the Montalban or White Mountain series of the Eozoic formations, a series extending, * Geology of Northern New England, p. 10. 202 STONES FOR BUILDING AND DECORATION. though not continuously, over fully two-thirds of the central and eastern part of the State. These granites are, as a rule, of a light gray, nearly white, color, fine grain, and are quarried in Concord, Fitzwilliam, Milford, Farmington, Hooksett, Pel- ham, Salem, Marlboro, Troy, Sunapee, Allentown, Hanover, Rumsey, Mason, and elsewhere. By far the most important of these, and indeed one of the most important granites of the United States, is the muscovite-biotite granite of West Con- cord in Merrimack county. This stone consists, according to Dr. Hawes,* of clear, glassy quartz, penetrated in every direction by minute, dark, rutile-like needles, snow-white twin orthoclase crystals, finely banded oligoclase, both white and black mica, and an occa- sional microscopic apatite crystal. In texture it is as fine as many marbles, though at times slightly porphyritic. Its remarkable feature, aside from color, texture and freedom from flaws, pyrite or other injurious constituent, is the wonderful ease with which it can be worked. Owing to its well developed rift and grain, blocks can be split out with a hammer with almost the ease of blocks of wood, though at the same time neither of these qualities are sufficiently prominent to prevent its being worked readily with the tool in any direction. It can, therefore, be used in statuary work, and is also used for general building and monumental work in the eastern cities. The quarries, of which there are several, are situated upon the eastern slope of Rattlesnake Hill, and means of transporta- tion are furnished by the Concord and Claremont Railroad, which skirts its base. The quarry openings are as a rule, situ- ated in the hillside, allowing thus natural drainage and abundant room for quarry dump, aside from ready facilities for quarrying and loading the material upon teams to be hauled to the rail- * Mineralogy and Lithology of New Hampshire, p. 194. STONES FOR BUILDING AND DECORATION. 2O3 road. The rock as shown at the openings is quite massive, and separated by two sets of irregular horizontal and vertical joints into natural blocks of varying sizes. Blemishes as seen at the quarries are surprisingly rare, and confined to a slight discolora- tion at the joints, and an occasional vein of fine grained granitic material. That the stone iseminentely durable is shown by the State- house and old State's-prison buildings, at Concord ; the former having been erected in 1816-19, and the latter in 1812. Al- though the stone in both of these cases was a result of mere surface quarrying and presumably scarcely better than that which is thrown into the dump to-day, both buildings are in an admirable state of preservation, and evidently, so far as the stone is concerned, good for centuries to come. This same stone has been used in the new post-office buildings at Concord and Manchester, and is the one selected for the new Congressional Library building in Washington, D. C. The gneisses of the State are less extensively quarried, and their uses are more local. A fine light gray stone of good quality comes from Peterborough, and a light pinkish stone, flecked with black and greenish, from Lebanon. New Jersey. The Archaean area, within which are comprised all the granitic and gneissiod rocks of New Jersey, crosses the State in a northeasterly and southwesterly direction in the form of a belt less than twenty miles in width at its greatest exten- sion, and less than half that amount at its southeastern ex- tremity. The belt enters the State from New York at a point comprised between the Ramapo River, in Bergen County, and the so-called Drowned Land, bordering along the Pennsylvania railroad in Sussex County. The southern limit lies in Warren, with a slight extension into the northern part of Hunterdon County. But few quarries are worked throughout the area above 2O4 STONES FOR BUILDING AND DECORATION. roughly outlined, though in a number of localities the gneissic rocks are so situated as to be worked at a comparatively small expense. Quarries at Dover, in Morris County, have furnished a large amount of stone for railroad construction. The stone is of medium texture and of a greenish gray color. A large quarry was opened a few years ago near Franklin, on the mountain east of the village ; but the place, though promising, was soon abandoned. The stone was adapted for heavy work. The transportation appeared to be too expensive for it to compete with stone coming by water routes.* Granites of the hornblende-biotite type, of fine grain and even texture, occur in the Vernon valley, along the eastern foot of Pochuck Mountain. The stone is regarded as of good quality, but little that is definite can as yet be said, owing to insufficient development. f New York. This State, although rich in marbles, limestones, and sandstones, produces little of general interest in the way of granite rock, though according to Smock \ " granites, syenites, gneisses, and mica schists occur in the counties of Rockland, Orange, Westchester, Putnam, and Dutchess, and on New York island. For constructive material quarries have been opened at many points, generally near railway lines on the Hudson river." The Breakneck and Storm King Mountain granite quarries were opened many years ago, and produce a gray, coarsely crystalline material, little of which finds its way out- side of the State. The more important of the true granites of the State, for monumental work, would seem to be the red variety produced at the various quarries on Grindstone Island (Jefferson County), in the St. Lawrence River. The stone, * Annual Report of State Geologist of New Jersey, 1886, pp. 41-42. f Annual Report of State Geologist of New Jersey, 1889. \ Bull, New York State Museum, No. 3, March, 1888, p. n. STONES FOR BUILDING AND DECORATION. 2O$ as represented in the National collection, is cleep red and coarsely crystalline, taking a high lustrous polish, and may well take rank as one of our most beautiful granites. The stone is designated by the writer in the tenth census report * as a hornblende granite, carrying in addition to quartz, red orthoclase and hornblende, a copper red mica, a few small apatite and zircon crystals, together with scattering pyrites and a little secondary calcite. The last two substances, if pre- valent throughout the quarry, must prove detrimental for exposed work. As shown by the two finely polished columns in the Senate Chamber of the new capitol building at Albany, New York, it is, however, a magnificent stone. There are said to be many outcrops of the stone on the island, especially on the western side, and small quarries have been opened at more than twenty different points. Prof. Smock states that the stone is shown by the outcrops to be very durable, and that in the larger quarries blocks twenty feet in length by six feet square are obtainable, The greater part of the product goes to Western cities, as Chicago, Cincinnati and Toledo, and to Canada. Much of the output is used for pav- ing blocks, and the waste for granulitic pavements in Montreal. The price is stated to range from $1.00 to $2.00 per cubic foot for blocks in sizes under twenty cubic feet. North Carolina. About 6 miles N. by E. of Concord, in Cabarrus County, there occurs a fine-grained, homogeneous deep pink granitic rock, almost wholly lacking in mica, which works readily and is admirably adapted for rock-faced work. The stone combines the warm and pleasing colors character- istic of many free stones, with the strength and general endur- ing qualities of granite, and with proper treatment leaves little to be desired, particularly for suburban residences. * Vol. x. Building Stone and Quarry Industry, p. 22. 2O6 STONES FOR BUILDING AND DECORATION. Some nine miles south of Salisbury, in Rowan County, occurs another granite eminently suited for rock-faced work. This is also of a pink cast, though very much lighter than that of Cabarrus County, and of a coarser texture. The stone is stated to occur in unlimited quantities, and blocks 60x40x30 feet are said to be obtainable. It weathers well and has been quarried for local use since 1878. A better stone could scarcely be desired for massive buildings where the ordinary gray granite is objectionable owing to its cold and gloomy aspect. Other pink granites, though of a dull and less desirable shade, are found at Cedar Creek, some 9 miles S. E. of Louis- burg, in Franklin County, and near Hillsboro, in Orange County. A peculiar dull red and buff-mottled gneissic stone is found some three-quarters of a mile west of Mooresville, in Iredell County, the character of the mottling corresponding to that of the so-called " raindrop " sandstone from L'Anse and Marquette, Michigan. The stone is stated to weather and work well, and occurs in such outcrops as to give a quarry face of from 40 to 50 feet. A coarse red granite, stated to be well adapted for general building, as well as ornamental work, occurs in bold outcrops at the crossing of Contentnea Creek and the Wheeling and Weldon R. R., in Nelson County. The stone has been used mainly for railroad work. A similar stone occurs near Wilson, in Wilson County. A dark-gray or sometimes reddish granite rendered porphy- ritic by large pink crystals of feldspar, and which recalls, in a general way, the well-known Shap granite of Cumberland, England, occurs near Rockingham, in Richmond County, on the line of the North Carolina Central R. R. Some two or three miles west of Rockingham is a somewhat similar stone, but with a peculiar olive tinge. The porphyritic structure of STONES FOR BUILDING AND DECORATION. 2O? the stone is less striking than that of the Shap granite above noted, and the weathering qualities perhaps doubtful. Some 5 miles S. E. of Davidson College, in Mecklenburg County, there occurs a coarse gray granite made up of white feldspars and opalescent quartz thickly studded with large deep green- ish-black spots, caused by segregations of black mica or horn- blende. The stone is as yet used only for foundations. The exposures are stated to cover an area of half an acre. Some four miles south of Salisbury are other occurrences of medium grained homogeneous gray granites outcropping in huge ledges forming the so-called Dunn's Mountain. The stone has been used in the post-office building at Raleigh. Gray granite closely simulating the ordinary types from the coast of Maine occur about four miles south of Winston, in Forsyth County, and some ten miles southwest of Greensbor- ough, Guilford County. The first mentioned is stated to weather well, to be procurable in any quantity, and in blocks of any desirable size. The Greensborough quarry is in close juxtaposition to the railroad, and is reported as producing a fair quality of stone, though of somewhat variable character. Other gray granites worthy of notice occur some 2\ miles north of Toisnot, in Edgecombe County ; near Gastonia, in Gaston County, and at Mount Airy, in Surry County. The first mentioned is used for general building and bridge work, and a railroad runs to the quarry. The principal market is Wilmington. Still other granites and gneisses at present of local impor- tance only occur in various parts of Buncombe, Stokes, Wake, Vance, McDowell, and Cleveland Counties. A very peculiar variety of granite, and one which may prove of value for ornamental purposes, occurs at Coolomee, in Davie County. The stone is composed of radiating green TJFIVERSITT 2C>8 STONES FOR BUILDING AND DECORATION. augites in rounded masses an inch or more in diameter, im- bedded in a white or pinkish ground mass of quartz and feld- spar. On a polished surface the effect is quite unique. Pennsylvania. Although ranking as second in importance in the list of stone-producing States, Pennsylvania furnishes very little in the way of granitic rock, and absolutely nothing in this line of more thin local interest. " The southern gneisses dis- trict, described in the geological reports of Pennsylvania as ranging from the Delaware River at Trenton to the Susque- hanna, south of the State line and lying south of the limestone valley of Montgomery, is the district in which are located nearly all the quarries of gneiss in the State, and those furnish- ing most of the material are in the vicinity of Philadelphia." The rock, which is for the most part a dark-gray hornblende gneiss, is quarried at Rittenhousetown, Twenty-first ward, and Germantown, Twenty-second ward, and Jenkinstown, in Montgomery County, and is used principally for the rough work of foundations in the near vicinity. In Chester, Dela- ware County, the gneiss bears mica in place of hornblende and is, as a rule, lighter in color. The quarries are in close prox- imity to the Delaware River, which affords an easy method of transportation to Philadelphia, the principal market. This stone is also used almost wholly for foundations, though in some cases it has been used as rock-faced work in the fronts of private dwellings, with rather a pleasing effect. Rhode Island. The granites of this State are nearly all fine- grained light gray or pink biotite granites, the principal quar- ries of which are situated some 2 miles east from Westerly, in Washington County. The rock is of fine and even texture and of excellent quality, and is much used for monumental work and general building. Other quarries of biotite granite occur at Smithfield, West Greenwich, Newport, and Niantic. A greenish, fine gray, hornblende gneiss is quarried at Diamond STONES FOR BUILDING AND DECORATION. 2OQ Hill, in Providence County. Aside from the Westerly rock the most of this material is for local market only. South Carolina. Although no granites from this State are to be found in our principal markets, it by no means follows that there is any deficiency in the supply. The collection in the National Museum shows, on the contrary, that excellent stones of this class occur in various localities. Near Winnsborough, in Fairfield County, quarries have recently been opened which furnish fine-grained gray biotite granite fully equal to any in the market. The quarries, as we are informed by the owner, Mr. W. Woodward, cover some 70 acres of bowlders and two large ledges, one 1 1 acres in extent and the other 6. The stone works readily and acquires an excellent polish. A pinkish granite also occurs in this same county. Other granites in this State, of which I have seen specimens, but concerning which I have but little accurate information, occur near Columbia, Richland County ; and in Newberry, Lexington, Edgefield, and Aiken Counties. The Columbia stone is of a light-gray color, apparently of excellent quality. It was used in the construction of the State House in that city, and is stated to be very durable. Tennessee. At the present time scarcely anything in the line of granitic rock is quarried in this State, and owing to the limited areas occupied by granite ledges it is more than doubt- ful if the granite quarrying ever assumes any great importance. Small outcrops of granite, gneiss, or mica schist occur in the extreme eastern and southern parts of Polk, Monroe, Cocke, Washington, Carter, and Johnson Counties, in the eastern part of the State, but even these are not in all cases suitable for any but the roughest work. The National collections contain an extremely coarse greenish epidotic granite, with large red porphyritic crystals of orthoclase, from Bench Mountain, in 2IO STONES FOR BUILDING AND DECORATION. Cocke County, which might perhaps be worked if there were a market. Texas. Red granites, both coarse and fine, occur in Burnet County, in this State, though at present neither are quarried to any extent. Both varieties carry biotite as the chief accessory mineral. The coarser variety corresponds closely with the coarse red granite from Platte Canon, Colorado. Their colors are dull and they seem better adapted for rough building than for monumental work, though the weathering qualities of either are, to say the least, doubtful. Red and gray granites also occur in Gillespie County. Utah Territory. A coarse, light gray granite occurs in inexhaustible quantities in Little Cottonwood Cafion, not far from Salt Lake City. So far the stone has been quarried only from bowlders that have been rolled down the canon, and the parent ledge remains untouched. This stone has been used in the construction of the new Mormon temple at Salt Lake City. It is apparently of excellent quality. Vermont. This State furnishes but little for the general market in the way of granitic rocks, from the fact that few of her quarries produce material not found elsewhere in New England, where there are better and cheaper facilities for transportation. Except in the north-eastern portion, embrac- ing nearly the whole of Essex County, granite is met with only in isolated outcrops, either in the form of mountain up- lifts, as Black Mountain in Dummerston, or in narrow belts traversing the calcareous mica schist formation, as at Marsh- field and Barre. In the gneiss formation, extending through Reading, Cavendish, Chester, and Grafton, on the western limit of the calcareous mica schist formation, the gneiss passes by insensible gradations into granite, and in many places there are afforded excellent opportunities for quarrying both stones equally well. The granite found in connection with the gneiss STONES FOR BUILDING AND DECORATION. 211 in these cases, is said to be, as a rule light colored, and of fine texture, but generally harder to work than those of the isolated outcrops, like that of Barre. This last mentioned stone is a fine grained biotite granite of excellent quality, and is found in inexhaustible quantities. The stone occurs in sheets vary- ing in thickness from a few inches to several feet.* Other granites deserving of especial mention are found in Brunswick, Essex County ; Morgan, Orleans County ; Ryegate, and St. Johnsbury, Caledonia County, and Woodbury in Wash- ington County. A very light, almost white, muscovite-bear- ing rock is also quarried at Bethel, in Windsor County. These granites, or at least the eruptive varieties, are regarded by Prof. Hitchcock as of Silurian or possibly Devonian age. The gneisses extending in a continuous belt from the Massa- chusetts line through the central portion of the State to Canada, furnish much valuable material for local building, curbing and flagging. Virginia. The Archaean area of Virginia, as mapped by Rogers,f comprises the tract lying east of the Blue Ridge Mountains, and a line extending from a point near Alexandria in Fairfax County southerly through Spottsylvania, Henrico, Chesterfield, Dinwiddie, Sussex, and Southampton Counties into North Carolina. But a small part of this area furnishes outcrops of quarriable material, and the principal works thus far developed are in Chesterfield and Dinwiddie Counties, on the James River, and in the immediate vicinity of Richmond. The quarries on the Richmond and Alleghany Railroad, near Richmond, produce a massive gray granite used for gen- eral building purposes, paving stone, and monumental work, and which is shipped more or less to all the States and cities * Geology of Vermont, vol. n. 1860, p. 737. f Geology of the Virginias, 1884. 212 STONES FOR BUILDING AND DECORATION. south of New England and as far west as Nebraska. Much of the material is dressed at the quarry, polishing works being located on the ground. Other quarries in Chesterfield County produce a very similar stone, the principal markets of which are in Richmond, Washington, Norfolk, Lynchburgh, and Philadelphia. Important quarries are also located at Man- chester in this same county. Other important quarries are in the Tuckahoe district, Henrico County, and Namozine dis- trict, Dinwiddie County. Stone from the last named locality was used in the construction of the post-office and custom house at Petersburgh, Virginia. The most important building yet constructed of the Virginia granites is the State, War, and Navy building in Washington. This is probably the most elaborate granite structure in the country. Near Fredericks- burgh is found a fine light gray muscovite-biotite granite closely resembling those of Hallowell, Maine., and Concord, New Hampshire, but it is not at present quarried to any extent. The granites of this State are, as a rule, fine-grained, biotite- bearing rocks, and of a light-gray color, and correspond in a remarkable degree with those of New England. In Amherst and Campbell Counties, near Lynchburg, a fine blue-gray biotite gneiss is quarried for general building purposes in the towns of the near vicinity. At Milan's Gap, in Madison County, is found a coarse some- what porphyritic granite of rather unique type, and which might be used with good effect in certain forms of ornamental work. The rock consists of quartz, a dull red feldspar, and compact aggregates of dull green epidote. The effect in either rock-faced or polished v/ork, is quite pleasing. The same rock is stated to occur in the Unaka Mountains, of North Caro- lina and East Tennessee, and is hence known as Unakyte* * Dana, Manual of Mineralogy and Lithology. STONES FOR BUILDING AND DECORATION. 21$ Wisconsin. The extensive outcrops of granitic rock in this State have been scarcely at all worked up to the present time, owing to the lack of transportation facilities. At the present writing the most important quarries are at Montello, Mar- quette County, and Wausau, Marathon County. The Mon- tello rock is very fine grained, compact, and of a dull pink color. Quarries were first opened here to furnish paving stones for the Chicago market, but the stone has since been used to a considerable extent for general building and monumental work. According to Prof. T. C. Chamberlain* the great Lauren- tian area of the northern part of the State is occupied largely by granite and gneiss, among which are some of exceptional excellence. Granitic rocks of greater or less excellence crop out along the upper reaches and tributaries of the Menominee, the Peshtigo, the Oconto, the Wolf, the Wisconsin, the Yellow, the Black, the Chippewa, the Flambeau, the Bad, and the Montreal Rivers. These are now being brought within the reach of cheap transportation, and should be utilized to the mutual benefit of those who work and those who use. Wyoming. " The only building stone which is quarried in Wyoming is at Sherman, the highest point of the Northern Pacific Railroad. At this point the summit of the Black Hills the road cuts through a heavy body of red granite similar to the Scotch, but with much larger crystals." This stone has been used to some extent in San Francisco and Sacra- mento, but is hard to work, owing to its coarseness and lack of tenacity.f * Geology of Wisconsin, vol. I. p. 66. f Report of Tenth Census, vol. x. p. 278. 214 STONES FOR BUILDING AND DECORATION. (6) FOREIGN GRANITIC ROCKS. Egypt. Granite of Syene. The now well-known red granite formerly called syenite, from near Syene, Egypt, and from which was constructed the numerous obelisks of the Egyptians, is stated to have been brought from Upper Egypt, where it occupies large tracts between the first cataract of the Nile and the town of Assonan, the ancient Syene. It was quarried by the Egyptians as far back as one thousand three hundred years before the Christian era, and has been fashioned into obelisks, sarcophagi, and colossal statues innumerable.* The rock, which is very coarse, is of a general reddish color and is com- posed of large crystals of red and whitish feldspars intermixed with clear, glassy quartz, and coal-black mica and hornblende. Some of the red feldspars are very large, exceeding an inch in length. This rock, though having proved very durable under Egyptian skies, possesses in itself no evident powers of resist- ance over thousands of other granites that might be mentioned. BRITISH PROVINCES OF NORTH AMERICA. British Columbia. Gray granite of good quality is said to have been obtained in considerable quantity from the large drift bowlders in the vicinity of Victoria. Granite occurs on Nelson Island in the Jarvis Inlet, and has been quarried to some extent. The Vancouver market is said to be supplied with an excellent variety of gray granite from the North Arm of Bur- rard Inlet.f Canada. Inexhaustible quantities of light gray granite are *See Hull, op. cit., p. 51; also Gorringe's "The Egyptian Obelisk," N. Y. ; 1882, or Journal Geological Society of London, vol. vn, iSso-'si, p. 9. f Annual Report Geological Survey of Canada, STONES FOR BUILDING AND DECORATION. 21$ stated * to occur in the township of Stanstead, just north of the Vermont line in the Province of Quebec. Other quite sim- ilar granites occur in the townships traversed by the Grand Trunk Railway, as at Barnston, Barford and Hereford, and many localities around the lakes at the heads of the St. Francis and Megantic rivers. Great Megantic Mountain is a mass of granite covering an area of twelve miles in the townships of Marston, Hampden and Ditton. A beautiful red hornblendic granite occurs in the townships of Greenville, Chatham and Wentworth. Hornblende granite is also found on Barrow and other islands in the St. Lawrence. These contain less horn- blende and more quartz than do those of Grenville and are said to resemble the red Scotch granite from Aberdeen. Quarries of red granite are also worked by Canadian com- panies at Kingston at the outlet of Lake Ontario in Ontario Province. It is stated that blocks of large size can be obtained free from all blemishes and flaws, and that the quantity is in- exhaustible. New Brunswick. In the vicinity of St. George, Kings County, occurs an inexhaustible supply of a red hornblendic intrusive granite, which is beginning to be extensively worked, and which has been introduced into the markets of the United States, where it is known as " Bay of Fundy granite." In text- ure the rock is medium coarse, very like that of Calais and Jones- borough, Maine, from which, however, it differs in depth of color and in bearing hornblende in place of mica. It is tough and compact, takes a brilliant polish, and is apparently durable. The quarries now worked are situated about 2^ miles from the town of St. George, where the rock occurs in rugged hills, and of varying shades of color from deep red to cream color or gray, the latter colors occurring in occasional large patches, 20 to 40 * Geology of Canada, 1863, p. 810. 2l6 STONES FOR BUILDING AND DECORATION. feet across, and of indefinite length. The quarries are opened along the hillside, where the rock is very conveniently jointed for getting out large blocks.* Nova Scotia. Gray mica-bearing granites of apparently ex- cellent quality, and varying in texture from medium fine and homogeneous to coarsely porphyritic are quarried at Sheiburne, and at Purcell's Cove, in Halifax County. These are exported to some extent into the United States. ENGLAND AND SCOTLAND. The granites brought into this country from Scotland are the coarse red from Peterhead, and the gray from Aberdeen. Both are excellent stones and are used very largely for monu- mental work, door-posts, and pillars in all our cities and towns. In point of beauty they are inferior to many of our native granites, but their well-established reputation will probably cause their being used for many years to come. The Peter- head granite is stated f to weigh 165.9 pounds per cubic foot, and to be composed of quartz, orthoclase, albite, and black mica. The Aberdeen granite has the same composition, except- ing that its triclinic feldspar is oligoclase in place of albite, and there is sometimes present a little white mica. It is of this latter stone that the city of Aberdeen is largely built. A coarse gray granite with large, well-defined porphyritic crystals of pink orthoclase is also imported from Shap, in northern England. None of these stones have any exact counterpart among the granites of this country, so far as now known. J * Report of G. F. Mathew, Geological Survey of Canada, i8y6-'77, PP- 345~ 349- f Building Construction, p. 20. \ See Harris' Granites and our Granite Industries (London, Crosby, Lock- wood & Co.,) for detailed accounts of the English, Irish and Scotch granites. STONES FOR BUILDING AND DECORATION. 2 1/ THE PORPHYRIES, OR PORPHYRITIC FELSITES. (l) COMPOSITION AND ORIGIN. The term porphyry, as properly used, refers simply to the structural features of the rock, and does not in itself alone in- dicate any particular kind of stone. It denotes that through- out a mass of rock of quite even texture are distributed numerous crystals of a mineral which having been the first to assume crystalline form, on the cooling of a molten magma, are larger and of a more perfect outline than those which formed subsequently. This structure is very common in many gran- ites, but is not particularly noticeable, owing to the coarse crys- tallization of the stone and the nearly uniform color of most of the constituents. Occasionally, as in the well known Shap granite from Cumberland in northern England, the large por- phyritic feldspars are of a flesh-red color, while the main mass of the stone is but gray, or pinkish, and the contrast is there- fore very striking. There is, however, a class of rocks, in which the mass of the rock, the groundmass, as it is technically called, is so dense and compact as to seem practically amorphous or non-crystal- line, and in which are imbedded large, scattering, quite per- fectly formed crystals, usually of quartz or feldspar. These large crystals being of a different color from the groundmass in which they lie, stand out in marked and often very beauti- ful contrast. It is to rocks of this nature that the name por- phyry has in times past, been chiefly applied. According to Hull* the name was originally applied to certain kinds of igneous rocks of reddish or purple tints, such as the red por- phyry of Egypt. Be this as it may, the term is now used * Building and Ornamental Stones, p. 63 2l8 STONES FOR BUILDING AND DECORATION. mainly in its adjective sense, since any kind of rock may, under certain conditions attending crystallization, assume this structure. We thus have porphyrytic granites, diabases, diorites, felsites and even limestones. Nevertheless there is a group of igneous rocks closely related to the granites in chemi- cal composition, in which this structure is so characteristically developed, that the names quartz or feldspar porphyry -, or por- phyritic felsite, are often applied to the entire group. (2) VARIETIES OF PORPHYRY. Accordingly as these porphyries vary in mineral composi- tion they are divided into two principal varieties: (i) Quartz porphyry, which consists of the fine-grained groundmass in which quartz alone or quartz and orthoclase are porphyritically developed, and (2) quartz-free or orthoclase porphyry, in which orthoclase alone prevails, no quartz appearing either porphy- ritically or in the groundmass. This last variety, it will be seen, bears the same relation to the quartz porphyries as does syenite to the granites. Through an entire disappearance of the porphyritic crystals, the rock passes into felsite. The por- phyries bear the same accessory minerals (hornblende, mica, etc.), as do the granites, but these are usually in such small particles as to be invisible to the naked eye. Porphyries, like granites, are of a variety of colors ; red, purple, gray, green, brown and black of a variety of shades are not uncommon, and when, as is so often the case, the porphy- ritic minerals contrast in color in a marked degree with the groundmass, the effect on a polished surface is very beautiful. (3) USE OF PORPHYRY. The porphyries are as a rule intensely hard, tough and with- out rift or grain. As a consequence they are scarcely at 'all STONES FOR BUILDING AND DECORATION. 2 19 used in this country, although among the most beautiful and indestructible of our rocks. The celebrated porphyries of Elf- dalen, Sweden, are wrought into a variety of objects of art, and with exceedingly beautiful effects. Visitors at the Cen- tennial Exposition in Philadelphia will recall the beautiful large column and inlaid table of this stone that were there displayed. (4) PORPHYRIES OF THE VARIOUS STATES AND TERRITORIES. Inexhaustible quantities of porphyries of a variety of colors and great beauty occur at Saugus, Maiden, Lynn and Marble- head, and other localities in eastern Massachusetts, but which have never been utilized to any extent owing to the cost of work- ing. Many of these are of exceptional beauty, presenting colors red as jasper, through all shades of pink, gray and even black, often beautifully variegated and brecciated in a variety of colors. Flow structures caused by the onward flowing of the rock while in a partially cooled condition often gives rise to a beautiful banding and interweaving of colors impossible to de- cribe, and which must be seen to be appreciated. The strik- ing beauty of this flow structure is sometimes heightened by the presence of angular fragments of variously colored por- tions of the rock, which, becoming broken from the parent mass, have been imbedded in a matrix of quite different color, as at Hingham, where the writer has found bright red frag- ments imbedded in a yellowish paste. The rock acquires a beautiful polish, and the fact that it has not ere this come into more general use is a sad comment upon the taste of our wealthier citizens. Nearly as indestructible as glass, and as beautiful as an agate, it is yet almost wholly ignored except for purposes of rough construction. 22O STONES FOR BUILDING AND DECORATION. A large variety of porphyries, varying in color from black to red, occurs also in New Hampshire, particularly near Water- vine, some of which would make fine ornamental stones. At Franconia, in the White Mountains, there occurs a porphyry conglomerate formed of fragments of jasper-red porphyry closely cemented into a compact rock, which is particularly beautiful. Porphyries are abundant in many other States, but are scarcely at all used. Maine, Pennsylvania, Missouri, Minnesota, and Wisconsin all contain good material, though, as little or no search has been made for the highly ornamental varieties, it is impossible to say what they can produce. At Green Lake, in the last named State, there occurs a beautiful stone of this class, almost black in color, with white porphyritic feldspars. It has been quarried to some extent near the town of Uttny, and polished columns of it may be seen in the German-American Bank Building and Union Depot at Saint Paul, Minnesota. It is greatly to be regretted that no economic method of working so beautiful and durable material has as yet been discovered. Near Charlotte, in Mecklenburgh County, N. C, there oc- curs a very light colored, almost white, quartz porphyry, which is penetrated by long parallel streaks or pencils of a dead black color. These are so arranged that, when cut across, the sur- face appears studded thickly with roundish and very irregular black points of all sizes up to half an inch in diameter. Cut parallel with the direction of the pencils, the surface is streaked with black lines, which sometimes assume beautiful fern-like or dendritic forms. The rock is intensely hard, tough and without definite rift. It can therefore be worked only at great cost, and is not regu- larly quarried. It has been used only locally for rough pur- STONES FOR BUILDING AND DECORATION. 221 poses, as for curbing, steps and sills. An analysis of this rock is given in the tables. A deep reddish quartz porphyry, somewhat resembling the Egyptian red porphyry, has been reported by the United States geologists as occurring near the Great Bend of the Carson River in Nevada. (5) FOREIGN QUARTZ PORPHYRIES. Russia. From the Isle of Hoghland, in the Gulf of Fin- land, the National Museum has received a variety of quartz por- phyries. These have mostly a dull red, very compact base, and carry large, nearly white, pinkish or reddish feldspars and glassy quartz in great profusion. The rocks acquire a good surface and polish, but are intensely hard. Other porphyritic and com- pact rocks, variously called diorites, keratites and porphyries, were received from the district of Katharinenburg, in the Urals, as noted in the published catalogue of the collections. THE LIPARITES. (l) ADAPTABILITY FOR CONSTRUCTIVE PURPOSES. Tertiary and post-Tertiary rocks of any kind are at present very little used for constructive purposes in the United States, owing, in the case of fragmental rocks, to their state of imper- fect consolidation and consequent feeble tenacity, and in the case of eruptives to their almost entire absence in those por- tions of the country that have become permanently settled, and where as a consequence there has arisen a demand for a more durable building material than wood. Of the eruptive rocks of this class only the liparites, andesites, and basalts have been 222 STONES FOR BUILDING AND DECORATION. at all utilized, and these to but a small extent. Their textures are, as a rule, such as to fit them only for the rougher kinds of construction, since, with the exception of the glassy varieties, they will not polish, and their rough appearance unfits them for any kind of interior decorative work. (2) MINERAL AND CHEMICAL COMPOSITION OF LIPARITE. Under the head of liparites are classed those acid eruptive rocks or lavas consisting chiefly of quartz and sanidin (the glassy variety of orthoclase) which are not older than Tertiary and which may be regarded as the younger effusive equivalents of the granites, quartz porphyries, and felsite pitchstones. In texture they vary from coarsely granitoid rocks, entirely crystalline throughout, through all intermediate felsitic stages to clear glassy forms. Structurally they vary from fine, com- pact, even-grained to coarsely porphyritic, vesicular, and sphe- rulitic forms ; well marked fluidal structure is common. The prevailing colors are chalky white to dark gray ; more rarely greenish, brownish, yellowish, and reddish varieties occur. The average chemical composition of liparite (quartz-tra- chyte) as given by Zirkel is silica, 76.36; alumina, 11.97 ; iron oxides, 2.01 ; lime, 1.09; magnesia, 0.56; potash, 3.70; soda, 4.53. Specific gravity, 2.55. (3) VARIETIES OF LIPARITE. According as they are crystalline throughout, felsitic and porphyritic or entirely glassy, liparites are classed as (i) gran- itic liparites or nevadites, (2) rhyolites, and (3) glassy liparites as obsidian, pumice, pear lite, w\& pitchstone. Of these only the felsitic and porphyritic variety rhyolite is as yet quarried. STONES FOR BUILDING AND DECORATION. 22$ (4) LIPARITES OF THE VARIOUS STATES AND TERRITORIES. Near the Mokelumne Hills, in Calaveras County, Califor- nia, rhyolite occurs in several different colors, and has been quarried to some extent for use in the immediate vicinity. The rock is also abundant in Colorado, New Mexico, Nevada, Utah, Montana, and other of the Western States and Territories. The glassy variety of rhyolite called obsidian is very abun- dant in certain parts of the West, and though as yet no attempt has been made to utilize the material there would seem no good reason for its not being used in small pieces for the finer kinds of decorative work. The rock, which is a natural glass formed by the rapid cooling of a molten magma, is of various colors, black, red, and greenish, and often beauti- fully spotted and streaked. The National collections show from the Yellowstone National Park, Glass Butte, Oregon, and other sources speci- mens of red obsidian spotted and streaked with black wavy lines in a way that is highly ornamental. The stone occurs naturally in a badly jointed condition, and could be obtained only in pieces of small size. Owing to its glassy fracture also it could be worked only with plain flat or rounded surfaces ; but, as it takes a high glass-like polish, it would be very desir- able for tops of small stands, paper weights, and inlaid work. THE SYENITES, TRACHYTES, AND PHONOLITES. (l) DEFINITION OF SYENITE. Under the name of Syenites are here included those rocks consisting essentially of orthoclase with or without one or more of the accessory minerals, mica, hornblende, or augite. 224 STONES FOR BUILDING AND DECORATION. They differ from granites only in the absence of quartz, and otherwise present a precisely parallel series. Thus we may have mica syenite (minette), hornblende syenite, augite syen- ite, etc.* (2) LOCALITIES OF SYENITE. At the present time syenites are but little quarried in this country, though there would seem to be no lack of material and of good quality. In and about Portland, Maine, there occur in the glacial drift many bowlders of a beautiful syenite, the exact source of which is not known to the author, but which can not be far to the northward. The rock consists mainly of bright lustrous gray orthoclase and coal-black hornblende, with occasionally a little black mica. In texture it is not too coarse, and the con- trast of colors such that one can scarcely imagine a more beauti- ful stone for rock- faced work. It is very tough, and, to judge from the bowlders, is also very durable, and not at all liable to discoloration on exposure. Hawes f describes augite syenites as occurring in Jackson, Columbia, and on Little Ascuntney Mountain, in New Ham- shire; also hornblende syenites as occurring at Red Hill and Moultonborough, Columbia, Sandwich, Stark, and Albany, in * Formerly it was customary to call by the name syenite a rock consisting of quartz, hornblende, and orthoclase, or what is now called a hornblende granite. The name takes its origin from Syene, Egypt, where a rock supposed to answer this description was originally quarried. Investigation has, however, shown that the Syene rock contains more mica than hornblende, and hence at best can not be classed as a true syenite even according to the old definition. Accord- ing to recent lithologists the Syene rock is a hornblende mica granite, while true sye-nite, as above stated, is a quartzless rock. f Geology of New Hampshire, vol. in. part iv STONES FOR BUILDING AND DECORATION. 22$ the same State. Dr. Wadsworth * also mentions a syenite as occurring in eastern Massachusetts, where it occupies a large proportion of the coast line between Salem and Manchester. None of these are as yet quarried. Near Hot springs, in Arkansas, there is quarried under the name of granite a tough gray rock of variable texture, consist- ing mainly of hornblende and elaeolite, and which would there- fore be classed as an elaeolite syenite. Some portions of the rock, as shown by the large block in the National collection, are fine-grained and homogeneous, while in others the elaeolite crystals reach some 2 or 3 inches in length. The appearance of the stone is excellent, but portions of it contain a large amount of pyrite and it needs to be selected with care if designed for exterior or highly ornamental work. According to Professor Brannerf these syenites occur in the vicinity of Little Rock where they form the Fourche Moun- tains, to the south-west of that city in Saline County, and at Magnet Cove on the Hot Springs Railroad in Hot Springs County. In the Little Rock district are found both blue-gray and light-gray, as well as several intermediate varieties. Both varieties have been used more or less, but it is only within the last two years that they can be said to have been put upon the market. The syenites of both the Little Rock and and Magnet Cove regions are intrusive, having penetrated rocks of Lower Carboniferous age ; whether those in Saline County are contemporaneous with the others is not as yet known but it seems probable that they are. The blue beds of the Fourche Mountains are all, so far as they have been uncovered, more or less jointed so that the rock comes out in angular masses of all sizes, many of them being much too large to be * Geological Magazine, May, 1885, p. 207. f Stone, Oct., 1889. 226 STONES FOR BUILDING AND DECORATION. handled. These masses, however, are perfectly solid and hom- ogeneous. The blue-gray variety is now extensively used for street paving as well as for architectural purposes. It is one of the best and handsomest of building stones, its colors making a pleasing contrast with other stones and bricks. The county Court-house and the fronts of most of the new business blocks in Little Rock are built of this stone. The light-gray variety usually occurs in extensive massive beds from which blocks of any desired size can 'be quarried. These rocks cover an area of many square miles, and there is no possibility of the beds ever becoming exhausted. They are moreover convenient to railway transportation, being cut by the Iron Mountain Rail- way near Little Rock, while the Diamond Jo quarry in the Magnet Cove area is within a thousand feet of the Hot Springs Railway. The cathedral in Little Rock is of the light-gray variety, which has also been employed in many minor structures. A syenitic rock bearing abundant elaeolite and frequently cancrinite and sodalite, and which must, therefore, also be classed as an elaeolite syenite occurs abundantly in the vicinity of Litchfield, Maine, and specimens of the rock have found their way into the building-stone collections of the National Museum. An examination of the rock does not, however, impress one particularly in its favor. Its durability is, to say the least, doubtful, and its varying texture and colors rather against it. (3) THE TRACHYTES AND PHONOLITES. Under the name of trachytes are comprehended by Rosen- busch those massive Tertiary and post-Tertiary volcanic rocks consisting essentially of sanidin and hornblende, augite or black mica, and which may be regarded as the younger equiva- lents of the syenites, and quartz free porphyries. STONES FOR BUILDING AND DECORATION. 22/ The average chemical composition is silica, 63.55$ 5 alumma, 1 8.0$; iron oxide, 6.15$; lime, 1.96$; magnesia, 0.88$. Spe- cific gravity, 2.65. In structure trachytes are rarely granular, but usually possess a fine scaly ormicro-felsitic groundmass, rendered por- phyritic by the development of scattering crystals of sanidin, hornblende, augite, or black mica. The texture is porous and possesses a characteristic roughness to the touch ; hence its name from the Greek word rpaxvZ rough. The prevailing colors are gray, yellowish or reddish. They may be divided into horn- blende, biotite, or augite trachytes, according as either of these accessory minerals predominates. Phonolites differ from trachytes in carrying one or both of the minerals nepheline or leucite in addition to the other con- stituents named. They bear the same relations then to the trachytes as do the elaeolite syenites to the syenites proper. Neither trachytes nor phonolites are, so far as now known, common rocks in the United States. Zirkel* describes numer- ous trachytes from the areas covered by the Fortieth Parallel survey, and Caswell f describes both trachytes and phonolites from the Black Hills, Dakota. Recent investigations by Wadsworth^; and Messrs. Hague and Iddings show, however, that the supposed trachytes of Zirkel were in large part if not altogether andesites, and it is very probable that similar tests applied to many other cases heretofore described would be productive of similar results. However this maybe, the utility of the rocks in America is purely prospective. Their colors and textures are such that they can never be * Microscopic Petrography of the Fortieth Parallel, f Geology of the Black Hills of Dakota. \ Proceedings Boston Society Natural History, vol. xxi. 1881, p. 243, and vol. xxu. 1883, p. 412. American Journal Science, vol. xxvi. 1884, p. 453, 228 STONES FOR BUILDING AND DECORATION. used for other purposes than rough construction, as is the case with the majority of the younger eruptives. AUGITE (ENSTATITE, HYPERSTHENE) PLAGIOCLASE ROCKS. (l) DIABASE. Diabase, from the Greek word diafiavis to pass over ; so called because the rock passes by imperceptible gradations into diorite. The diabases are crystalline granular rocks, composed essentially of plagioclase feldspar and augite, or a rhombic pyroxene, with nearly always magnetite and frequently olivine. Geologically they are pre-Tertiary eruptive rocks, basic in composition, occurring in dikes, intruded sheets and bosses. In structure they are as a rule massive, but schistose varieties occur and more rarely spherulitic forms. The texture is as a rule fine, compact, and homogeneous, though sometimes por- phyritic or amygdaloidal. The colors are somber, varying from greenish through dark gray to nearly black, or sometimes black when freshly quarried, but becoming greenish on drying.* According to Zirkel, the average chemical composition of diabase is as follows : Per cent. Silica 49.54 Alumina 14.05 Iron protoxide 14.27 Lime , 8.20 Magnesia 5.28 Potash 1.16 Soda 3.88 Water 2.29 * Mr. J . P. Iddings suggests that the change in color from dark blue black, to greenish, as noticed in diabase of New Jersey, is due to the drying of the serpentine or chlorite, which results from the alteration of the included olivine. (American Journal of Science, May, 1886, p. 330. STOKES FOR BUILDING AND DECORATION. 229 Average specific gravity, 2.8, which is equal to a weight of 175 pounds per cubic foot. In classification two principal varieties of diabase are recog- nized, the distinction being founded upon the presence or absence of the mineral olivine. We thus have (i) olivine diabase, or diabase with olivine, and (2) diabase proper, or diabase without olivine. Owing to its lack of definite rift, com- pact texture, and hardness, diabase can, as a rule, be worked only with difficulty and usually at a cost considerably greater than that of granite. It is therefore not extensively quarried, though of late years it has come into more general use for paving purposes, and still more recently for building and monu- mental work. The green antique porphyry or Marmor Lacedce- monium viride, formerly much used for pavements and general inlaid decorative work in Greece and Rome, is according to Delesse, a diabase consisting of large greenish crystals of labradorite embedded in a fine compact groundmass of the same feldspar, together with augite and titaniferous iron. The quarries from which the stone was taken are stated by Hull to be situated between Sparta and Marathon, in Greece. A stone of a similar character and closely resembling it in color and structure is abundant among the drift bowlders of eastern Massachusetts, but its exact derivation is unknown. In the eastern United States the dikes and sheets of dia- base are frequently associated with deposits of red or brown Triassic sandstone, which are also extensively quarried, as wift be noticed further on. Concerning these dikes Professor Dana writes :*. " It is remarkable that these fractures (through which the diabase was forced to the surface) should have taken place in * Manual of Geology, third edition, p. 417. 230 STONES FOR BUILDING AND DECORATION. great numbers just where the Triassic beds exist, and only sparingly east or west of them ; and also that the igneous rock should be essentially the same throughout the thousands of miles from Nova Scotia to North Carolina. The igneous and aqueous rocks (sandstone) are so associated that they neces- sarily come into the same history. Mount Tom and Mount Holyoke, of Massachusetts, are examples of these trap ridges ; also East Rock and West Rock, near New Haven, and the Hanging Hills, near Meriden, in Connecticut ; the Palisades along the Hudson River, in New York ; Bergen Hill and other elevations in New Jersey. " In Nova Scotia trap ridges skirt the whole red sandstone region and face directly the Bay of Fundy ; Cape Blomidon, noted for its zeolitic minerals, lies at its northern extremity on the Bay of Mines. " In Connecticut the ridges and dikes are extremely numer- ous, showing avast amount of igneous action. . . . They com- mence near Long Island Sound, at New Haven, where they form some bold eminences, and extend through the State and nearly to the northern boundary of Massachusetts. Mounts Holyoke and Tom are in the system. The general course is parallel to that of the Green Mountains. " Although the greater part of the dikes is confined to the sandstone regions, there are a few outside, intersecting the crystalline rocks and following the same direction, and part, at least, of the same system. " Even the little Southbury Triassic region, lying isolated in western Connecticut, has a large number of trap ridges, and such a group of them as occurs nowhere else in New England outside of the Triassic. Their direction and positions in over- lapping series are the same as in the Connecticut valley. "The trap usually forms hills with a bold columnar front and sloping back. When nearly north and south in direction STONES FOR BUILDING AND DECORATION. 23! the bold front is to the westward in the Connecticut Valley, and to the eastward in New Jersey. It has come up through fissures in the sandstone, which varied from a few inches to 300 feet or more in breadth. In many cases it has made its way out by opening the layers of sandstone, and in such cases it stands with a bold front, facing in the direction toward which it thus ascended." Connecticut. The extensive diabase outcrops noted above as occurring at East and West Rocks, north of New Haven in this State, are quarried for foundation walls and for. paving purposes in the near vicinity. The rock is too dull in color for ornamental work. Maine. Diabase is quarried at three localities in this State, Addison, Vinalhaven, and Tenant's Harbor. At Addison the rock occurs in extensive outcrops close by the water's edge. Single blocks 66 by 10 by 20 feet have been moved in the quarries, and natural blocks 90 by 10 by 15 feet occur. The chief defects in the stone are said to be the so-called "knots," which consist of irregular patches of coarse feldspar and dark crystals of hornblende. There are also occasional seams, caus- ing the rock to split unfavorably. The rock is moderately fine-grained, very dark gray, sometimes almost black or spotted black and white on a polished surface and of a fine appearance. It has been used in the walls inclosing the Capitol grounds at Washington, in the construction of a bank at Montreal, and is quite generally used for monuments in Boston, New York, Brooklyn, Washington, Montreal, and Quebec. The Vinal- haven diabase is less extensively worked on account of its hardness. It is of finer grain than the Addison stone and uniformly dark-gray, nearly black in color. It is used to some extent for building material and also in cemetery work. The Tenant's Harbor (St. George, Knox County) stone closely resembles that of Addison, and is used for similar purposes. 232 STOA T ES FOR BUILDING AND DECORATION. These are all most excellent stones, and it is a matter for con- gratulation that they are being so extensively introduced, and, to some extent, replacing the marbles in monumental work. The cost of working is, owing to their compact structure, somewhat greater than that of granite, but the results fully justify the increased outlay. All the above, it should be noted are known commercially as black granite.* Massachusetts. Diabase is quarried for foundations walls, general constructive purposes, and monumental work, at Med- ford aad Somerville in this State. The stone from these local- ities is coarser, lighter in color, and much inferior in point of beauty to that just described. Missouri. Intrusive masses of diabase occur at various points in the southeastern part of this State, particularly in Madison County. Attempts have been made to quarry the material from outcrops near Mine La Motte Station at Skrain- ka, but the works are no longer in operation. The rock is stated to be covered with from ten to thirty feet of stripping and to have been so violently contorted and broken that it is impossible to quarry dimension stone from it. It is fine grain- ed dark gray to almost black in color, splits and dresses easily, and takes an excellent polish, but cannot be utilized for mon- umental purposes for reasons above noted. Up to date it has been used mainly in the manufacture of paving blocks. f New Jersey. The extensive outcrops of diabase, or "trap * It should be remarked that all of these diabases differ radically in structure and composition from any others here mentioned, and deserve a more thorough and careful study than they have yet received. All contain a rhombic pyroxene pleochroic in red, green, and brown colors, and which is evidently hypersthene, while certain sections of the Addison rock show a pyroxenic constituent carry- ing an abundance of the rhombic inclosures so characteristic of entstatite. Prof. Rosenbusch in his recent work includes this rock with the gabbros. f Bulletin No. I Missouri Geological Survey, 1890, p. 42. STONES FOR BUILDING AND DECORATION. 233 rock," known as the Palisades of the Hudson River, in north- eastern New Jersey, furnish an inexhaustible supply of this material, and which is at present quite extensively quarried about Guttenberg, Weehawken, west New York, and south- ward along the Palisades as far as Montgomery Avenue in Jersey City. The rock is used chiefly for paving, and the quar- ries are small affairs worked by gangs of from two to five men. Two sizes of blocks are prepared. The larger, which are known as specification blocks, are 4 by 8 or 10 inches on the head and 7 to 8 inches deep. The second size, which are called square blocks, are 5 to 6 inches square and 6 to 7 inches deep. The specification blocks bring about $30 per thousand in the market, and the square only about $20 per thousand. It is estimated that some 4,000,000 of the specification and 1,000,000 of the square blocks were quarried in 1887, valued at $140,000. There are three principal grades of the rock quarried. A fine-grained variety at Mount Pleasant, a rocky hill north of the Pennsylvania Railroad ; a light-gray variety at Bergen Cut, south of the railroad ; and a dark, almost black, variety at Weehawken and West New York. Other quarries cf this rock are worked at Orange Mountain ; Snake Hill, Hudson County, and at Morris Hill in Paterson. In the western part of the State the outcrops are not so extensive, but quarries are worked at Rocky Hill, near Titusville, Smith's Hill, and near Lambertville. At Rock Church, 4 miles from Lambert- ville, the rock is quarried and used for monumental work as well as for general building purposes, being put upon the market under the name of black granite. The rock from the Palisade quarries has also been quite extensively used in and about Jersey City for building purposes. St. Patrick's Cathe- dral, and the Hudson County Court-house, as well as many private buildings, are of this stone, but the effect as a whole is 234 STONES FOR BUILDING AND DECORATION. not pleasing, owing to the sombre colors of the material. Employed in connection with brick or lighter stone, to give variety and contrast, the effect is admirable. The finely broken stone is also used very extensively for railroad ballast and road-making. Several of the quarries near Orange Mountain have machines for breaking up the stone for this purpose.* Pennsylvania. The principal quarries of diabase in this State are at Collins Station, Lancaster County, and near York Haven, York County. At the latter place the face of the quarries is about 70 feet in height. The rock lies in huge natural blocks sometimes weighing hundreds of tons and having curved outlines giving them a sort of oval shape. Stone from this quarry is used only by the Northern Central Railroad in the construction of bridges and culverts. At Collins Station diabase is more extensively quarried than at any other locality in the State. The stone is used for all manner of building purposes and monumental work. The foundation of the new Harrisburg Post-office and the Soldiers' Monument in this city are from this material. In the vicinity of Gettysburg diabase is quite extensively quarried, and has been used for head-stones in the national cemetery at this place. It is also used for general building being put on the market under the name of Gettysburg granite. Virginia. As in the States to the east and north, the Triassic beds of Virginia are cut by large dikes of " trap " or diabase, and which in some cases are capable of affording excellent material for paving blocks and general building and ornamental work. So .far as the author is aware quarries have been opened upon these dikes in but two localities, at Cedar * See Annual Report State Geologist of New Jersey, 1881, pp. 60-63. S7*ONES FOR BUILDING AND DECORATION. 235 Run, ^ear Catlett's Station on the Virginia Midland Railroad, and near Goose Creek, about three miles east of Leesburgh, in Loudoun County. Specimens of these rocks which the writer has examined represent the coarser varieties of our Mesozoic diabase, are of a dark gray color, very strong, and apparently durable. That from Goose Creek has been found to stand a pressure of 23,000 pounds per square inch, and, as the author has observed, undergoes no change on an exposure of twenty- five years other than a slight and in no way objectionable darkening of color. Neither stone has been used as yet for other than paving purposes^ and bridge abutments, though they are apparently well adapted to all kinds of work for which their color and hardness qualify them. (2) GABBRO AND NORITE. The rock gabbro differs from diabase mainly in containing the foliated pyroxene diallage in place of augite. It is not at present quarried to any extent in this country, though for no apparent reason other than that it is difficult to work. Very extensive outcrops of a dark gray, almost black gab- bro of medium fineness of texture occur in the immediate vicinity of Baltimore, Maryland, but which have been quarried only for purposes of rough construction close at hand. The rock is popularly known as "niggerhead " owing to its hard- ness, dark color, and its occurrence in rounded bowlders on the surface.* At Rice's Point, near Duluth, Minnesota, there occurs an inexhaustible supply of a coarse gabbro, which has been stud- * This is the rock the interesting petrographical features of which have lately been made known by Dr. Williams, of Johns Hopkins University. See Bull. 'U. S. Geological Survey, no. 28. 236 STONES FOR BUILDING AND DECORATION. ied and described by Professor WinchelL* The feldspar of the rock, which is labradorite, according to the authority quot- ed, sometimes prevails as at Beaver Bay, in crystals one-half to three-fourths of an inch across, and to the ahnost entire exclu- sion of other constituents. In this form the rock varies from lavender blue or bluish gray to light green, and acquires a beautiful surface and polish, and is considered as constituting a valuable material for ornamental slabs and columns. The typical gabbro of the region is of a dark blue-gray color, and "has been employed in a few buildings at Duluth, both in cut trimmings and for rough walls." It has also been used for monuments and for bases, to which it is especially adapted, being cut under the chisel and polished more easily than any of the crystalline rocks that contain quartz. The stone is known popularly as Duluth granite. The same kind of rock occurs at Taylor's Falls, but is little used, though favorably situated for quarrying and transporting. A rock closely allied to the gabbros and diabases is the so- called norite, which consists essentially of the minerals hyper- sthene and a plagioclase feldspar. Rocks of this type are now quarried on the north and west slopes of Prospect Hill, near Keeseville, Essex County, New York and at Vergennes, Ver- mont. The stone of the first named locality is known com- mercially as Au Sable granite, and the second as Labradorite granite. Both are coarse-grained, dark-gray rocks, much resem- bling the darker varieties of the Quincy granites, from which, however, they differ radically in mineral composition. They take a high lustrous polish, frequently show a beautiful bright bluish chatoyant play of colors and are seemingly admirably adapted for polished columns, pilasters, and other decorative work. * Geology of Minnesota, vol. I, pp. 148-9. STONES FOR BUILDING AND DECORATION. The lasting power of the norites, when polished, is yet to be ascertained. After an exposure of untold years in the quarry bed the surface has turned white. No data are obtain- able for calculating their lasting qualities in the finished struc- ture. As seen by the writer the Keeseville rock in the quarry bed is cut by innumerable clean sharp joints at intervals of every few feet, and in some cases of even fractions of an inch. In the freshly quarried stone these are quite invisible and appear on a polished surface as faint parallel lines, as fine, straight and sharp cut as though made with a diamond. As a measure of precaution such jointed blocks had best be avoided for purposes of fine monumental work, since it seems extremely probable that the joints will open on exposure for prolonged periods. Professor Egleston who tested this stone for the company, reports that on exposure to the heat of a furnace at temperatures varying from 800 to 1,850 Fahr. samples turned light chocolate-brown, but did not seriously disintegrate. Its crushing strength as given by the same authority is 29,000 pounds per square inch.* A dark greenish black norite or hypersthene gabbro with accessory hornblende and black mica is found in Anson County, North Carolina on the line of the Carolina Central Railway. The stone has been worked for the Raleigh market, and so far as may be judged from small pieces compares very favorably with other of our so-called black granites. It cor- responds more nearly with the Addison [Maine] gabbro than with either of the above mentioned rocks. A fine grained dark gray rock of this nature showing abundant small flecks of dark mica and carrying in microscopic proportions abundant hypersthene occurs at Clifton, Maine. The rock though not now quarried is admirably adapted for rock-faced work, and so * See Smock's Building-stone in New York, p. 232. 238 STONES FOR BUILDING AND DECORATION. far as may be judged from appearances would be found to work readily. The rock compares in general appearances with the mica diorite of Croton Landing, New York, but is of finer grain. A coarser, more granitic variety of the same rock is found in Calais in Washington County, and has, as I am informed, been worked experimentally by the Red Beach Granite Company. (3) MELAPHYR. The melaphyrs, as defined by Prof. Rosenbusch, are massive eruptive rocks, consisting of plagioclase, augite, and olivine, with free iron oxides and an amorphous or " porphyry " base. They are thus of the same mineral composition as the basalts and olivine diabases, but differ structurally, and belong in great part to the Carboniferous and older Permian formations. Al- though very abundant in many parts of the United States, they are scarcely at all quarried owing to their dull colors and poor working qualities. In the Brighton district of Boston, but a few miles out of the city proper, and in other localities in the vicinity, there occur small outcrops of a greenish or sometimes purplish melaphyr, or " amygdaloid," the lithological nature of which was, I be- lieve, first correctly stated by E. R. Bent on* The prevailing color of the rock is greenish, often amygdaloidal, the amygdules being composed often of epidote, thus spotting the surface with greenish-yellow blotches. The rock is greatly altered, only the feldspars of the original constituents remaining now recogniz- able, while chlorite, quartz, calcite, epidote, and several other minerals occur as secondary products. The rock is neverthe- * Proceedings Boston Society, vol. xx, p. 416. STONES FOR BUILDING AND DECORATION. 239 less very firm, compact, and durable, and is being quarried to some extent for rough work. It would seem fitted for a yet wider architectural application. (4) BASALT. This rock differs from diabase only in point of geological age, being a product of post-Tertiary eruptions. It is, as a rule, less perfectly crystalline, still retaining portions of its glassy magma. Owing in great part to the fact that basalts occur in this country only in the western and more recently set- tled portions, as do also the andesites and rhyolites, they have been heretofore but little utilized. There would seem, however, no reason for excluding the rock from the list of available building materials in those regions where it occurs in such form as to be accessible. At Petaluma, Bridgeport, and other places around the bay of San Francisco there lie immense sheets of this rock, but which are worked now only for paving materials. Like the andesites and rhyolites the basalts will not polish, and their colors are such as to exclude them from all forms of interior decorative work. AMPHIBOLE PLAGIOCLASE ROCKS (TRAP AND GREEN STONE, IN PART). (l) DIORITES AND KERSANTITES. The name diorite from the Greek word #zopz ^- WARDWELI. CHANNELLING MACHINE. pages 340 to 343). At the Vermont marble quarries both the Sullivan diamond pointed drill and the Ingersoll impact drill are used for gadding. The bottom holes are usually drilled to a depth equalling about one-half the width of the block to be extracted, though this depth, as well as the frequency 322 STONES FOR BUILDING AND DECORATION. of the holes, must necessarily vary with the character of the rift of the rock. (4) SANDSTONE QUARRYING. In the quarrying of the Triassic sandstones at Portland, Connecticut, the channelling machine is also used to some extent, but the prevailing method of loosening large blocks is by deep drill holes charged with heavy blasts of powder. These holes are made by a crude machine driven by cranks, like an ordinary derrick, and are 10 inches in diameter and about 20 feet deep. Into these are put from 25 to 75 pounds of powder, contained in a flattened or oval tin cannister, with the edges unsoldered and closed at the ends by paper or cloth. This is placed in the hole in such a position that a plane pass- ing through its edges is in line with the desired break, and fired. In this way large blocks are freed from the quarry, and these are then broken to any required size, as follows : The workmen first cut with a pick a sharp groove some 4 to 8 inches deep along the full length of the line where it is desired the stone shall break. Into this groove are placed, at intervals of a few inches, large iron wedges, which are then in turn struck repeated blows by heavy sledge-hammers in the hands of the quarrymen until the rock falls apart. This process will be made plain by reference to Plate IX. In some of the quarries of softer sandstone no machines at all are used, the channelling" being done entirely by hand-chisels or with picks, and the stone forced out by means of iron bars alone, or split out with plug and feather. To allow of this, however, the stone must be evenly and thinly bedded, and the different sheets adhere to one another with but slight tenacity, as is the case with certain of the New York " bluestones " and Berea grits of Ohio. In the New York quarries the vertical joints are said to be so STONES FOR BUILDING AND DECORATION. 323 numerous as to practically do away with the necessity of channelling. Powder is still largely used in most of the smaller quarries, and in all those of granitic rock for throwing off large masses. If properly used with these harder varieties, it is doubtful if any serious harm results, but in the quarrying of marble and other soft stones, its use can not be too strongly condemned. It has been suggested that the rapid disintegration of the Carrara marble is caused in part by the incipient fractures induced through the crude methods of quarrying employed. Except- ing when, as in the case of granite, no other means can be employed, explosives of all kinds are to be avoided. When necessary, they should be used in a lewis hole, whereby direc- tion may be given to the force of the discharge and the shock distributed over large surfaces. (5) CUTTING AND DRESSING STONE. In cutting and dressing stone the same slow hand processes that were in vogue hundreds of years ago are still largely em- ployed. There have been, it is true, many machines invented for this purpose, but the majority of them are far from satis- factory in their working qualities, or the cost of running them is so great that they can be used only by the larger and wealthier firms. After a large mass has been split from the quarry bed it is broken into blocks of the required size and shape by means of wedges. A series of holes, three-fourths of an inch in diameter and a few inches deep, is drilled along the line where it is desired the stone shall break, and into each of these two thin half round pieces of soft iron called " feathers" are placed, and a small steel wedge or "plug" placed between. The quarryman then moves along this line striking with his 324 STONES FOR BUILDING AND DECORATION. hammer each wedge in its turn till the desired strain is pro- duced and the stone falls apart. There is a chance for a greater display of skill in this work than may at first appear. Nearly every stone, however com- pact, has a distinct grain and rift, along which it can be relied FIG. 7. ^DRILLING HOLES FOR SPLITTING STONE WITH PLUG AND FEATHERS. on to split with comparative ease and safety. To know the rift and be able to take proper advantage of it is an important item, and it is astonishing how readily an experienced workman will cause a stone to take the desired shape through a know- ledge of this property. STONES FOR BUILDING AND DECORATION. This process of splitting stone with wedges is said * to have been first brought into general use in this country by a poor mechanic named Tarbox, of Danvers, Massachusetts. Through the influence of Governor Robbins, who stumbled upon samples of his work by the merest accident, this man was in- duced in 1 798 to go to Quincy and teach his art to the quarrymen of that place. So much did the adoption of this simple method facilitate granite-working that the price of the cut material dropped within the space of a few months over 60 per cent. Prior to this time the stone after being blasted from the quarry in irregular blocks was squarred down to the proper size by cutting a groove along a straight line with a sharp-edged tool called an axhammer, and then striking with a heavy hammer repeated blows on both sides of the groove until the rock was broken asunder.f * Proceedings American Academy, vol. iv. 1859, p. 353. f In Pattee's History of Old Braintree and Quincy occurs this passage : " On Sunday, 1803, the first experiment in splitting stone with wedges was made by Josiah Bemis, George Stearns, and Michael Wilde. It proved suc- cessful, and so elated were these gentlemen on this memorable Sunday that they adjourned to Nevvcomb's hotel, where they partook of a sumptuous feast. The wedges used in this experiment were flat, and differed somewhat from those now in use. " As to who can justly claim to be the first to bring this method of splitting into general use the author has no means of ascertaining. That none of the above can justly claim to have invented the process is evident from the follow- ing : " I told thee that I had been informed that the grindstones and millstones were split with wooden pegs drove in, but I did not say that those rocks about this house could be split after that manner, but that I could split them, and had been used to split rocks to make steps, door-sills, and large window cases all of stone, and pig-troughs and water-troughs. I have split rocks 17 feet long and built four houses of hewn stone, split out of the rocks with my own hands. My method is to bore the rock about 6 inches deep, having drawn a line from one end to the other, in which I bore holes about a foot asunder, more or less, according to the freeness of the rock ; if it be 3 or 4 or 5 feet thick, 10, 12, or 326 STONES FOR BUILDING AND DECORATION. This method is said to have been introduced into Quincy somewhere about 1725 '50, by German emigrants, and, crude 16 inches deep. The hole should be an inch and a quarter diameter if the rock be 2 feet thick, but if it be 5 or 6 feet thick the holes should be an inch and three-quarters diameter. There must be provided twice as many iron wedges as holes, and one-half of them must -be fully as long as the hole is deep and made round at one end, just fit to drop into the hole, and the other half may be made a little longer, and thicker one way, and blunt pointed. All the holes must have their wedges drove together, one after another, gently, that they may strain all alike. You may hear by their ringing when they strain well. Then with the sharp edge of the sledge strike hard on the rock in the line between every wedge, which will crack the rock ; then drive the wedges again. It gen- erally opens in a few minutes after the wedges are drove tight. Then, with an iron bar or long levers, raise them up and lay the two pieces flat and bore and split them in what shape and dimensions you please. If the rock is anything free you may split them as true almost as sawn timber, and by this method you may split almost any rock, for you may add almost any power you please by boring the holes deeper and closer together." (From letter of John Bartram to Jared Elliot, dated January 24, 1757. See Darlington's Memorandum of Bartram and Marshall, p. 375.) The precise date at which these four stone houses were built is not stated, but the work above quoted contains an illustration of John Bartram's house, near Darby, Delaware County, Pa. This house, which is of stone, was erected about 1730. Hence we must conclude that the art of splitting stone in this manner was known to some at least as early as this date. It is stated (Grueber, Die Baumaterialien-Lehre, pp. 60, 61) that in Finland, even at the present day, granite is split from the quarry-bed through the expan- sive force of ice. A series of holes, from a foot to 15 inches apart and from 2 to 3 feet deep, according to the size of the block to be loosened, is driven along the line of desired rift after the usual custom. These holes are then filled with water and tightly plugged. The operation is put off until late in the season and until the approach of a frost. The water in the holes then freezes, and by its expansion fractures the rock in the direction of the line of holes. Blocks of 400 tons weight are stated to be broken out in this way. A more ancient method consisted in simply plugging the holes with dry wooden wedges and then thoroughly saturating them with water, the swelling wood acting in the same way as the freezing water. Another ancient and well-known method consisted in building a fire around the stone, and when it was thoroughly heated striking it with heavy hammers or throwing cold water upon it. In splitting stone the STONES FOR BUILDING AND DECORATION. 327 as it may seem, was a vast improvement over that used in pre- pairing stone for the construction of King's Chapel, erected m i749-'54, on the corner of School and Tremont streets, Boston. Here we are told the stone was first heated by building a fire around it, and then broken by means of heavy iron balls let fall from a considerable height. With such difficulties as these to contend with it is not surprising that the building should have been considered a wonder when completed, and that people coming to Boston from a distance made it a point to see and admire the structure. The wonder, however, was not that the granite could be broken into shape by such methods, but u that stone enough could be found in the vicinity of Boston fit for the hammer to construct such an entire building. But it seemed to be universally conceded that enough more like it could not be found to build such another." After a block is broken from the quarry bed it is trimmed to the desired size and shape by means of a variety of imple- ments, according to the hardness of the stone and the charac- ter of the desired finish. In dressing granite and other hard stone the tools ordinarily ancient Romans are said to have sprinkled the hot stone with vinegar, though whether they thereby accelerated the splitting or caused the stone to break along definite lines is not known. Quartz rocks, it is stated, can be made to split in definite directions by wetting them while hot, or laying a wet cord along the line it is desired they shall cleave. The wet line gives rise to a small crack, and the operation is completed by striking heavy blows with wooden mallets. According to M. Raimondi, the ancient Peruvians split up the stone in the quar- ry by first heating it with burning straw and then throwing cold water upon it. To carve the stone and obtain a bas relief, this writer contends that the work- men covered with ashes the lines of the designs which they intended to have in relief, and then heated the whole surface. The parts of the stone which were submitted immediately to the action of fire became decomposed to a greater or less depth, while the designs, protected by ashes, remained intact. To com- plete the work the sculptor had but to carve out the decomposed rock with his copper chisel. 328 STOA T ES FOR BUILDING AND DECORATION. used are the set or pitching chisel, the spalling hammer, pean hammer, bush hammer, hand hammer, chisel, and point. With the set the rough block is trimmed down to a line. Then the irregular surface is worked down by the point, which is driven by the hand hammer. After pointing, are used the pean and the patent or bush hammers in turn, beginning with the 4-cut, and thence working down with the 6-cut, 8-cut, lo-cut, and 12- cut, or until the desired surface is obtained. The condition of the hammered surface at the completion of one of the hammer- ings should be such that each cut in the hammer traces a line its full length on the stone at each blow. The single cut or pean hammer should leave no unevenness exceeding one-eighth of an inch, and each finer cut reduces the unevenness left by the preceding. The 12-cut should leave no irregularities upon the surface of the stone other than the indentations made by the impinging of the plates in the ham- mer. The lines of the cut are made so as to be vertical in ex- posed vertical faces when the block is in position. On hori- zontal and unexposed faces they are cut straight across in any convenient direction. With sawn surfaces of course much of the preliminary work is done away with, as the surface is already sufficiently smooth. It is at present customary to saw only such stone as are designed for polishing or some kind of smooth finish. In preparing a stone for polishing, the surface is first made smooth as possible by sawing or by the means above desig- nated. It is then further reduced by means of wet sand and emery of varing degrees of fineness. Small blocks are now usually ground on a revolving iron bed, on which the abrading material is shovelled and kept wet by a stream of water from overhead. With larger blocks a slab of stone is drawn by the workmen back and forth across the surface on which the wet sand has already been placed. On the finer grades of STONES FOR BUILDING AND DECORATION. white marble emery is not used, as it stains ; fortunately, owing to the softness of these stones, it is readily dispensed with. After being ground, the surface is rubbed by a sharp, evenly gritted sandstone called a hone, and then with pumice- stone. On granites it is often customary to give a " skin coat " by rubbing the block, after the final emerying, on the smooth, wet grinding bed, without any abrading material, until a perfectly smooth surface and dull polish is obtained. When this point is reached and the surface must be quite free from scratches and blemishes, or a good polish is impossible the polish is produced by means of polishing putty (oxide of tin) rubbed on with wet felt. In cheap work it is customary to use oxalic acid in connection with or entirely in place of the polishing putty. This enables the'production of a polish with less labor, but it is also less durable. A high grade of polish can only be produced by skilled workmen, and each one has his own peculiar methods, varying in trifling particulars from that given above. In many of the larger works where steam power is used, it is said to be cus- tomary to mix a quantity of very finely ground metallic lead with the putty. By this means a higher gloss is produced, and also one that is very durable. All the larger works now use machinery in both grinding and polishing. Descriptions of these will be given in the following chapter. Sundry attempts have been made to utilize the sand-blast process, so extensively used in glasswork, for carving on stone ; but so far, with few exceptions, these attempts have met with but poor success. In 1875-76, Messrs. Sheldon & Slason, of West Rutland, having a large Government contract in prepar- ing head-stones for soldiers' graves in National cemeteries, in- troduced the system with considerable success. The process consisted in covering those parts of the stone to be left uncut 330 STONES FOR BU'ILDING AND DECORATION. with an iron shield, while letters and figures of chilled iron were placed upon those portions which were to stand out in relief. The blast then being directed against the stone cuts away very quickly the unprotected parts. By this means the name, com- pany, regiment, and rank of soldiers, could be cut on a stone in less than five minutes, and two hundred and fifty four thousand stones thus lettered and having dimensions of 3 feet in length, 10 inches in width, and 4 inches in thickness, were placed in the national cemeteries at a cost of but $864,000. The sandblast process has also been used with good results on the hard red quartzite of Sioux Falls, as will be noted later. (6) QUARRYING AND SPLITTING SLATE. In quarrying slate the methods vary greatly according to the disposition of the beds, and no attempt will be made here at a detailed description. Ordinary blasting powder is em- ployed in loosening the blocks, and great skill and sagacity is shown by experienced quarry-men in so manipulating the blast as to produce the desired effects of freeing the rock from the quarry-bed without shattering the stone. After a block is re- moved from the quarry it is subject to special treatment ac- cording to the purpose to which the stone is to be put. If for roofing-slate, the block is taken from the quarry to the splitters' shanty, where it is taken in charge by a splitter and his two assistants. The first assistant takes the block and reduces it to pieces about 2 inches in thickness, and of a length and breadth a little greater than those of the slates to be made. This is done by a process called " sculping," which is as fol- lows : A notch is cut in one end of the block with the sculp- ing chisel, and the edge of this notch is trimmed out with a gouge to a smooth groove extending across the end of the block and perpendicular to the upper and lower surfaces ; the STONES FOR BUILDING AND DECORATION. 331 sculping chisel is then set into this groove and driven with a mallet until a cleft starts, which by care- ful manipulation is guided directly across the block. The up- per surface of the block is kept wet with water so that the crack may be more readily seen. If the slate is perfectly uni- form in shape and texture, and the blows upon the sculping chisel are directed straight with the grain, the crack follows the grain in a straight F IG - 8. line across the block. Almost invariably, however, the crack deviates to the right or left, when it must be brought back by directing the blow on the sculp in the direction in which it is desired to turn the break, or by striking with a heavy mallet on that side of the block toward which it is desired the crack shall turn. Some slates can be sculped across the grain, but nearly all must be broken in this direction. From the first assistant or "sculper," the block goes to the splitter who by means of a mallet and broad thin chisel splits it through the middle, continuing to thus divide each piece into halves until the desired thinness is obtained. It is necessary to keep the edges of the blocks moist from the -time they are removed from the quarry until they are split. From the splitter the thin but irregularly shaped pieces pass to the second assistant who trims 332 STOiVES FOR BUILDING AND DECORATION. them into definite sizes and rectangular shapes. This is done either by hand or by machine. To trim by hand a straight edged strip of iron or steel is fastened horizontally upon one of the upper edges of a rectangular block of wood some 2 to 4 feet in length. The trimmer then lays the sheet of slate upon the block allowing the edge to be trimmed to project over this strip, and then by means of a long heavy knife with a bent handle cuts off the overlying edge, thus reducing it to the re- quired size and shape, Two kinds of machines for doing this work are now in use. In general they may be said to consist of an iron frame-work some 2^- feet high, with a horizontal knife-edge upon its upper edge. Against this knife is made to work by means of a treadle another knife, curved in out-line, which is thrown upward again by means of a spring, after being brought down by the treadle-movement. At right angles to this knife-edge, on one side of the machine, an iron arm pro- jects toward the workman ; this arm has notches cut into it for the different sizes of the slate. The difference between the two kinds of machines is said to consist chiefly in the arrange- ment of the cutting-knife, one working as stated above, while the other revolves on an axle something in the manner of an ordinary corn cutter. See Fig. 8. . Slates are sawn by means of an ordinary circular saw, such as is used in sawing lumber, and are planed by machines such as are used in planing metals, as are other soft stone. Some of the hard slates used for tiling have to be cut by means of cir- cular saws with teeth of black diamond.* In trimming out school slates at the Pennsylvania quarries * Detailed and very closely resembling accounts of the methods of working slate are given by F. W. Sperr, in Report Tenth Census, vol. x, pp. 38-42, and E. Prime, Jr., Report D 3, vol. i, pp. 138-143, 2d Geology Survey, Pennsyl- vania. To these the reader is respectfully referred. PLATE X. ~ KINDS OF FINISH. Fig. i. Rockface. Fig. 4. Toothed chiseled. Fig. 2 and 3. Pointed face. Fig. 5. Square drove. Fig. 6. Patent hammered. To face page 333. STONES FOR BUILDING AND DECORATION. 333 there is used a square saw of chilled iron some ten or twelve inches in diameter and with one long projecting tooth at each of its four corners. This revolves with great rapidity and clips off the thin edges as quickly and neatly as could be desired. (7) KINDS OF FINISH. The more common kinds of finish applied to stone are de- scribed below ; the figures on Plate X. being drawn from samples in the National collections at Washington. (1) Rock face. This is the natural face of the rock as broken from the quarry, or but slightly trimmed down by the pitching tool. As in this and all the figures given, it is frequently sur- rounded by a margin of drove work. (2) Pointed face. In this finish the natural face of the rock has been trimmed down by means of the sharp-pointed tool called a point. It is used principally for exterior work, as in the walls of a building. Two common styles of pointing are shown. (3) Ax -hammered face. This finish is produced by striking upon the surface repeated blows with a sharp-faced implement called an ax or pean hammer. It closely resembles the next, but is coarser. Used in steps, house trimmings, and other ex- terior work. (4) Patent hammered. This finish is produced by striking repeated blows upon the smooth surface of the rock with the rough-faced implement called a patent hammer. Five grades of fineness are commonly recognized, the 4-cut, 6-cut, 8-cut, 10- cut, and 12-cut surfaces, made by hammers composed of four, six, eight, ten, and twelve plates, respectively. A very common finish for the finer kinds of exterior work. (5) Bush hammered. This finish resembles closely the tooth 334 STOA T ES FOR BUILDING AND DECORATION. chiseled or very fine pointing. It is used mostly on soft stone. (See descriptions of bush and patent hammers on p. 348). (6) Square drove. The square drove surface is made with a wide steel chisel with a smooth edge, called a drove. It is quite common to use this style of finish as a border to the rock-face or pointed surfaces in many kinds of exterior work. (7) Tooth chiselled. This finish is produced by means of a wide steel chisel with an edge toothed like that of a saw. This and the square drove are used principally upon limestones, marbles, and sandstones, the granites being too hard to cut in this manner. (8) Sawed face. This is the surface of the rock as left by the saw ; the saw used for the purpose being a thin, smooth blade of soft iron, fed with sharp sand or chilled iron. This and the following styles, although possessing distinctive characteristics easily recognizable by the eye, are of such a nature that their likenesses cannot be well reproduced on paper. Hence no attempt at illustration has been mcide. (9) Fine sand finish.- To produce this finish the chiselled or sawn surface is rubbed smooth by means of a block of stone and fine wet sand, or on the machines yet to be described. (10) Pumice finish. This is a very smooth but unpolished surface produced by smooth rubbing with pumice or Scotch hone. (11) Polished surface. Two kinds of polished surfaces are made the acid gloss and the putty gloss. For either the surface of the stone is made as smooth as possible by means of sand, or emery, and pumice, or hone, after which it is rubbed with moist woollen cloth and oxalic acid, or polishing putty. The latter produces the best and most lasting gloss, but re- STONES FOR BUILDING AND DECORATION. 335 quires more labor. Frequently the two methods are combined, especially in tombstone work. MACHINES AND IMPLEMENTS USED IN STONE- WORKING, (l) DRILLS AND DRILLING MACHINES. Of the many machines that have from time to time been in- vented for working stone we can here mention only the principal ones that are to-day in actual use. Drills. The old time method of drilling by means of a flat pointed drill called a jumper,* which is held by one workman while others strike upon it alternate blows with heavy hammers, al- though still in use at many quarries, has been largely superseded by steam-drills of various kinds. A simple form of the steam-drill, and one now in very general use, is that shown in the accom- panying figure. The drill FIG. 9 ECLIPSE ROCK DRILL. proper is fastened directly to the piston, which can be inclined * In English quarries the name jumper is given to a hand drill some four and a half to five and a half feet long and with an iron ball welded to the middle of the rod. In using it the workman places one hand under the ball or the knob, and with the other grasps the rod about half way between the knob and 336 STONES FOR BUILDING AND DECORATION. at any angle, thus fitting it for ordinary quarrying or for tun- nelling. It is driven either by steam or by compressed air. A different adaptation of the same principle is employed in the channelling and gadding machines used in getting out dimen- sion stone. Figures of these are also here given. The drill and cylinder are attached to the horizontal bar by means of a clamp, which can be loosened or tightened at will. By this means a dozen or more holes can be cut by simply sliding the drill along the bar and without moving the entire machine. (2) CHANNELLING MACHINES. The channelling machine shown on page 321 was invented by George J. Ward well of Rutland, Vermont. The first successful machine being built by him in 1863. As may be seen, the channeller is essentially a locomotive machine driven by power, usually steam, moving over a steel-rail track which is placed on the quarry bed. It carries a single gang- drill on one side, or two FIG. io. IMPROVED QUARRY BAR. SUcll drills One Oil each side. These are raised and dropped by a lever and crank ar- the upper end. Then standing upright on the block of stone he lifts the jumper allowing it to fall again of its own weight repeatedly upon the spot where the hole is to be made. It is mainly used in drilling small holes for plug and leather splitting. (Harris' Granite and our Granite Industries, p. 117.) STONES FOR BUILDING AND DECORATION. 337 rangement. The gang of cutters forming the drill is composed of five steel bars, 7 to 14 feet in length, sharpened at the end and securely clamped together. Of the five cutters, two have diagonal edges ; the other three their edges trans- verse. The centre of the middle largest extends lowest, so that the five form something like a stepped arrangement, away from the centre. The drill, lifted, drops with great force and rapidly creases a chan- nel into the rock. The single gang ma- chine is operated by two men, the double by three. As it runs backward and for- ward over the rock the machine is re- versed without stop- ping, and as it goes the cutters deliver their strokes, it is claimed, at the rate- of one hundred and fifty per minute. The ~ U.- machine feeds for- ATTACHED. ward on the track half an inch at each stroke, cutting half an inch or more every time of passing. The single machine will cut from 40 to 80 square feet of channel per day in marble or limestone and at a cost of from 5 to 20 cents per square foot. 33? STONES FOR BUILDING AND DECORATION. The double machine will do twice the amount of work. A good workman by the old hand process would formerly cut from 5 to 10 feet ; that is, a groove one foot deep and from 5 to 10 feet long per day. For this he would receive from 25 to 30 cents per foot.* Another machine for doing the same work as that just de- scribed is the Saunders channelling machine shown in the illustration (Figs. 11 and 12), and which has recently come into use in the Vermont quarries. This differs from the Wardwell in several important particulars, prominent among which are these : (i) The cutting tool is attached rigidly to the piston, so that the blow is dealt directly by the steam pressure in the cylinder and without the interven- tion of any cranks, levers, or springs. (2) The cutting tools are made adjustable at any angle to the right, FIG. 12. SAUNDERS CHANNELLING MACHINE MAKING \Q^ forward OT back- SIDEHILL CUTS BOILERS DETACHED. ward. The machine is thus capable of making transverse and sidehill cuts, and does what is known as " cutting out the corners " in quarry- ing ; and (3) it can be used in chambers where the distance between the floor and roof is but six feet and can be used in tunnels and headings. The machine carries five drills in the gang, with three *The Marble Border of Western New England, p. 44. STONES FOR BUILDING AND DECORATION. 339 straight points and two diagonal ones. These are arranged as seen in the accompanying cut : The average capacity of the machine, as claimed by the com- pany's circular, is as follows : In marble, 80 to 100 square feet of channel in ten hours. In sandstone, 150 to 200 square feet of channel in ten hours. In limestone, 120 to 150 square feet of channel in ten hours. The diamond channelling machine is shown in the figure on page 340. According to the company's circular this machine employs if inch drill-bits, which are attached to drill-rods of varying lengths, adapted to any required depth of channel up to Qjfeet. The channel may be made open or partly closed, the latter by leaving slight spaces between the holes, to be afterward chipped out. But the whole operation of a clear cut is made simultaneously with the boring by means of an intercutting guide, which answers this purpose very well. The drill can be made to vary in di- rection from perpendicular to 50 degrees slant for putting down the tunnel and angle cuts. If necessary the boiler can be left at a distance from the machine, the steam being con- veyed by hose. 340 STOATS FOR BUILDING AND DECORATION. (3) GADDING AND GADDING MACHINES. The diamond gadder is shown on page 341. According to the company's circular the machine takes its name from the class of work for which it was especially designed and which is known among quarriers as gadding. When the requisite channel cuts are made about a block of marble to be removed, it is necessary to undercut the block in order to release it. This is usually accom- plished by drilling a series of holes beneath it, and then, by wedges, the block is split from its bed. The machine is placed upon a platform on trucks arranged to run upon a track. When adjusted for work it may be braced by the pointed legs shown. The boring apparatus is attached by a swivel to a perpendicular guide - bar. This guide-bar is secured to the boiler behind it, which forms the main support of the machine. Upon the guide-bar the boring apparatus may be raised or lowered at pleasure, for FIG. 14. DIAMOND CHANNELLING MACHINE. STONES FOR BUILDING AND DECORATION. 341 the purpose of boring a series of holes in a perpendicular line if desired. Upon the swivel the boring apparatus may be turned, so as to bore in any direction within the plane of the swivel-plate. The illustration shows the drill-rod or spindle placed near the base of the ma- chine, and so as to bore horizontally. At one end of the spindle is the drill - head, armed with carbons, and supplied with small apertures or outlets for water. At the other end of the spindle is attached a hose for supplying water to the drill- head. A rapid re- volving movement is communicated to the drill-spindle by the gears shown. The speed and feed move- ment may be regu- lated by the operator with reference to the hardness or softness, coarseness or fineness, of the material to be bored ; and the feed movement may be instantly reversed at pleasure. The machine is so constructed that the drill-spindle may be re- moved and another inserted in the same holder, adjusted to bore in the opposite direction, the boring apparatus being FIG. 15. DIAMOND GADDER. 342 STONES FOR BUILDING AND DECORATION. driven by a double-cylinder engine. A continuation of one of the piston-rods through the cylinder forms the plunger to a small pump placed above the cylinder, which supplies water to the boiler and also forces it through the drill- spindle and head. These jets of water wash out all the borings made, and keep the drill-head from heating. The usual feed of this drill in marble is from 4 to 5 inches per minute. Still another style of gad- ding-machine is used in the Vermont quarries, and which is but an especial adaptation of the eclipse-drill shown on page 335. It is claimed that FIG. I6.-INGERSOL STANDARD GADDER t^J s machine will " put in holes close to the bottom of the quarry, in a horizontal position along the bench, into the roof, or perpendicularly into the floor, as desired." (4) GRINDING AND POLISHING MACHINES. In the larger works the grinding and polishing already described is now done by steam power. For flat surfaces a circular horizontally revolving iron plate or grating, attached to the lower end of a vertical shaft, with elbow joint, is used, the workman guiding it to any portion of the surface he may desire by means of the handle ; the abrading substance being S7VNES FOR BUILDING AND DECORATION. 343 sand or emery, as before. With felt attached to the plate the same form of machine is also used for polishing. Blocks of such size as can be handled by the workmen are usually ground upon horizontally revolving iron beds some 8 or 10 feet in diameter. In making straight or only slightly-curved moldings the form is first carved out with the chisel, and then a plate of cast iron, fitted as accurately as possible, is made by means of a long arm, to travel back and forth over the stone with sand or emery, or putty powder and felt, as the case may be. These are Called pendulum ma- FlG - I?.-PLAIN QUARRY FRAME IN POSITION 111 FOR UNDERCUTTING OR GADDING. chines. The actual labor is thus greatly reduced, and a higher and more lasting polish obtained than is possible by the old hand methods. (5) LATHES AND PLANERS. For turning posts and pillars lathes are now very generally used for granite as well as for softer stone. In easy working varieties, as sandstone, limestone, or serpentine, the cutting tool is a simple chisel, much like that used in turning metals, and held in a clamp in the same manner. With the harder rocks, like the granites, however, this method is ineffectual, and the cutting tool is in the form of a thin steel disk some 6 or 8 inches in diameter, which is so arranged as to revolve with the stone in the lathe when pressed against it at a sharp angle. By this means large and beautiful columns can be made at far less cost than by the old hand-processes. A monster machine of 344 STONES FOR BUILDING AND DECORATION. this character, seen by the writer in the Vinalhaven quarries in 1880, is capable of taking a block 25 feet in length and 5 feet in diameter and turning it down to a perfect column. With the softer varieties of stone a plain surface, sufficiently smooth for flagging, is produced by means of planing machines similar to those in use for planing metals. For doing the same work on hard material like granite a planer, with revolving cutting disks of chilled iron, similar to those used in the lathes, has been devised. This machine is shown in the accompany. figure, page 346. (6) MACHINES FOR SAWING, In sawing marble and other soft stones the same method, with some modifications, is employed as was in use, according to Professor Seely,* three hundred years before the Christian era. The principle consists simply of a smooth flat blade of soft iron, set in a frame and fed with sharp sand and water. The saws are now frequently set in gangs of a dozen or more in a single frame, and several gangs are tended by one man, who shovels on the wet sand as it is needed, while fine streams of water from overhead wash it beneath the blade as it swings backward and forward in its slowly deepening groove. Some attempts at automatic feeders have been made, but they are not as yet in general use, This method has been found inapplicable to cutting granite, owing to the greater hardness of the material. Recently a * The Marble Border ot Western New England. Proceedings Middlebury Historical Society, vol. i. part n. p. 28. STOA r ES FOR BUILDING AND DECORATION. 345 sand composed of globules of chilled iron has been used to good advantage, and still more recently crushed steel. The great drawback to the use of these materials, so far as the author has observed, is the care necessary to avoid staining the stone by rust from the wet metal during the time the machine is not running. This is done by wetting down the stone in the saw frame with a thick solution of lime-water (whitewash) prior to leaving the saws for the night. Circular saws, with diamond teeth, have been used to some extent, but have been found too expensive for ordinary work. In sawing slate circular saws are used, such as are employed in sawing lumber. Philo Tom- linson, who was engaged in marble sawing at Marbledale, Connecticut, near the date 1800, is stated by Professor Seely* to have been one of the first to successfully apply the gang-saw- system in this country. For sawing circular apertures in the tops of wash-stands or getting out tops for small tables a saw made of plates of soft iron bent in the form of a cylinder and revolved by a vertical shaft is used. Sand, emery, or globules of chilled iron form the cutting material, as in the saws just mentioned. A recent European invention for sawing stone consists of a twisted cord of steel made to run around pulleys like a band-saw. The cord is composed of three steel wires, loosely twisted together, but stretched tightly over the pul- leys, and is made to run at a high rate of speed. The swift successive blows from the ridges of the cord, delivered along the narrow line, disintegrates the stone much more rapidly, it is claimed, than the iron blades fed with sand, the usual rate of cutting in blocks of soft limestone being about 24 inches an hour, and in Carrara marble a little more than 9 inches an hour. Brittany granite is cut at the rate of nearly * Op. cit. p. 29. 346 STONES FOR BUILDING AND DECORATION. i\ inches an hour, and even porphyry can be worked at the rate of eight-tenths of an inch an hour. In certain Belgian marble quarries the saw is said to have been used to advantage in cutting the rock from the quarry bed. In thus utilizing it the floor is first cleared as for channelling machines, and then, by means of large cylindrical drills, fed with metallic sand, a shaft 27 inches in diameter is cut to the desired depth, the cores being removed en- tire, as in the common tubular diamond drills. Two of these holes are sunk at proper distances apart and guides set up in them, on which move frames carrying pulleys of a diameter somewhat less than that of the holes ; over these pul- leys the cord saw is stretched ; motion is then imparted to the pulleys by a simple sys- tem of transmission, and the saws cut without in- terruption until the bot- tom of the drill-pit or FIG. 18. MCDONALD STONE CUTTING MACHINE. shaft is readied. A great saving of time and material is claimed for this invention, but although it seems to promise well it is not at present STONES FOR BUILDING AND DECORATION. 347 in use in this country, nor has the author ever had oppor- tunity for examining it.* (7) THE 'SAND BLAST. As already noted, the sand blast has been utilized to some extent in the work of lettering head-stones, and for producing delicate tracings on the Sioux Falls quartzite. That the pro- fess is still so little used is due, as I am informed, to the oppo- sition of trades-unions, and not to any deficiency of adapt- ability in the process itself. (8) HAND IMPLEMENTS. Face Hammer. This is a heavy square-faced hammer, weighing from 15 to 25 pounds, and used for roughly shaping the blocks as they come from the quarry. It is sometimes made with both faces alike or again with one face flat and the other drawn out into a cutting edge (Fig. 10, PI. XI.) The cavil differs only in having one face drawn out into a pyramidal point. Ax or pean hammer. A hammer made with two opposite cutting edges, as seen in Fig. 13, PI. xi. The edges are some- times toothed roughly, when it is called the toothed ax. Patent or bush hammer. A hammer made of four, six, eight, ten, or more thin blades of steel, bolted together so as to form a single piece, the striking faces of which are deeply and sharply grooved. This hammer is said to have been invented by Mr. Joseph Richards, of Quincy, Massachusetts, about * This apparatus was figured and described in the Scientific American for March 6, 1886, p. 147. A more detailed description, fully illustrated, has since appeared in Stone (Indianapolis, Indiana), Sept., 1889. 34-S STONES FOR BUILDING AND DECORATION. i83i-'4O. As first constructed the head was composed of a single piece, instead of several, as now (see Fig. 12, PI. XI). In some works this is called the bush hammer. Crandall. This consists of a bar of malleable iron, about 2 feet in length, and slightly flattened at one end, through which is a slot three-eighths of an inch wide and 3 inches long. Through this slot are passed ten double-headed points of one- fourth inch square steel, 9 inches long, which are held in place by a key. The writer has never seen this instrument in use. Hand hammer. A smooth-faced hammer, with two striking faces, weighing from 2 to 5 pounds. It is used for hand-dril- ling, pointing, and chiselling in the harder kinds of rocks (see Fig. 1 6, PI. Xl). The usual form has both faces alike. Mallet. This is a wooden implement, with a cylindrical head, used in place of the hammer in cutting the softer stones, as marbles and sandstones (Fig. 15, PL Xl). Sledge or striking hammer. A heavy, smooth-faced ham- mer, weighing from 10 to 25 pounds, used in striking the drills in hand-drilling or in driving large wedges for splitting stone, Fig. 11, PL XI. Pick. An instrument resembling the ordinary pickax used in digging, but somewhat shorter and stouter. It is used on the softer varieties of stones, for rough dressing or for channel- ling prior to wedging. Pitching chisel. A steel chisel, the cutting face of which is rectangular in outline and with sharp angles or corners. It is used for trimming down the edges to a straight line. See Fig. 7, PL XL The chipper (Fig. 6) is used for very similar pur- poses. Chisel or drove. This is a steel chisel, the cutting edge of which is drawn out wide and thin as shown in Fig. 2, PL XI. It zr 1 7 EH SIT 7 PLATE XI. f \i\AiuuuuS K M $ * yi CJ v_y HAND IMPLEMENTS USED IN STONE WORKING. To face page 349, STONES FOR BUILDING AND DECORATION. 349 is used principally on the softer varieties of rock in producing the so-called "drove-work." Splitting chisel. A steel chisel, made as shown in Fig. 8, PL XI, and used for splitting and general cutting on hard stone like granite. Other forms of chisels, used only on soft stone and driven with the wooden mallet, are shown in Figs. 3 and 9. Tooth chisel. A chisel like the drove chisel, but with the edge toothed like a saw (see Fig. I, PI. XI), used only on soft stones like marble and sandstones. Point. A steel implement, with the cutting end in the form of a pyramidal point (see Fig. 4, PL xi), used in the production of the finish known as point work and also in the smoothing down of rough surfaces prior to using the ax or some other tool for fine work. Points for use on hard stone and driven by the hammer have the upper end finished as shown in Figs. 6 and 7. Wedge or plug. Steel wedges vary greatly in size. Those used in the process of splitting, called plug and feather (Fig. 14, PL xi), are but two or 3 inches in length, while those used in quarrying for splitting off large blocks are often a foot or more long and correspondingly large. Hand drill. A small steel drill from 8 to 15 inches in length, held in one hand and driven by the hand-hammer (Fig. 5), used in making holes for " plug and feather " splitting and other light work. Grub saw. A saw for cutting stone by hand. It consists of a plate of soft iron from one-twentieth to one-tenth of an inch in thickness and from 6 inches to 4 feet in length ; the blade is notched on the lower edge and fitted with a wooden back for convenience in handling and to prevent bending. Sand or emery is the cutting material, as with the steam saws (Fig. 17, PL XI). 35 STONES FOR BUILDING AND DECORATION. THE WEATHERING OF BUILDING STONE. That all stone are not equally well adapted for the various kinds of structural purposes must be apparent to the most casual observer. Not merely is there a wide difference in dur- ability among stones of various kinds, but materials well adapt- ed for some situations may, owing to an inherent weakness prove quite unfit for use where climatic or other conditions are such as to render injuriously conspicuous defects wholly unap- parent under more favorable circumstances. Stones, as a whole, do not possess the firm and unchangeable characteris- tics commonly attributed to them by the popular mind. There is perhaps as wide a variation in lasting qualities as among woods, mortars and cements. It is true that the various detrimental changes which may take place are often the product of years of exposure, but this is no excuse for the ignoring of such a possibility. He who designs or constructs a house builds not for himself alone, but for the entire community and for future as well as present generations. Whatever he may do with the interior is to a certain extent his own affair, but not so with the exterior. The construction of a dwelling, business block, public building or monument, is a matter in which each individual citizen has a perfect right to have an active interest, since the structure once erected be- comes for a time a fixed feature of the landscape and an object by which not merely the taste and abilities of the architect and builder are to be judged, but that of the community as well. STONES FOR BUILDING AND DECORATION. 351 The external features of the structure are constantly before the public and must exercise some influence either beneficial or derogatory upon public taste. It behooves the builder therefore, quite aside from all economic considerations, to select for his purpose such material as shall be most harmoni- ous in the finished structure, and possess as well such qualities as shall be enabled to withstand the ravages of time without serious injury. There are few things more conspicuously unsightly than a rich and elaborate building constructed from materials which under the ordinary chemical and physical agencies of the atmo- sphere have become discolored or disintegrated. Yet our cities and towns are replete with illustrations of such lack of forethought or of ignorance on the part of builders. One of America's greatest architects has designed a struct- ure of more than ordinary merit, but in which the walls are of massive granite, while the window stools, caps, cornices and projections in general, which of all parts of the structure are most liable to injury from disintegration, are of a soft and fri- able sandstone. The items of color and cost alone were ap- parently here considered. The Executive Mansion and por- tions of the Patent Office and Capitol buildings in Washington are of a sandstone so poor in enduring qualities that it has been found necessary to paint them periodically in order to keep them in a condition anyway presentable. The gigantic pile designed as a monument to the Father of his Country and which stands upon the banks of the Potomac in this same city is, so far as quality of material is concerned, not merely wrong side out, but wrong end up, as well. The best and most enduring material in the entire structure lies in the inner courses of the upper portion. The poorest and weakest is comprised in the outer portion of the first 150 feet measured from the ground up, where it has to bear the weight 35 2 STONES FOR BUILDING AND DECORATION. of the entire superincumbent 300 feet, and receives as well the wash from all the rain which falls upon the portion above. The cracked and scaling fronts of brownstone in New York and other of our older cities furnish again abundant illustra- tions of lack of care and judgment in the selection of materials, while the House of Parliament in London, which is said to have so badly scaled and disintegrated in certain portions as to necessitate repairing before the structure was actually finished, shows that such a failing is by no means confined to America. Within the last fifty years many more or less complex series of tests of durability have been inaugurated when the erection of public buildings have been under consideration, but the sub- ject has as yet by no means received the attention it deserves. It is for the purpose of emphasizing the necessity of care in the selection of such materials that the chapter herewith pre- sented has been written. The term weathering, as applied to stone, includes the series of physical changes induced by alternations of heat and cold, or by friction, as well as the more complex series of chemical changes, such as may be comprised under the heads of oxid- ation, deoxidation, hydration, and solution. Since a stone ex- posed in the walls of a building may be subjected to the in- fluence of any one or the combined influences of several of these agencies, whereby serious consequences, as of discolor- ation or disintegration may result, it is important to consider in more or less detail, their comparative energies under varying .conditions and upon the various kinds of stone commonly em- ployed for structural purposes. STONES FOR BUILDING AND DECORATION. 353 (i) PHYSICAL AGENCIES. Heat and cold. It is safe to say that none of the conditions under which a stone is commonly placed are more trying than those presented by the ordinary changes of temperature in a climate like that of our Northern and Eastern States. Stones, as a rule, possess but a low conducting power and slight elas- ticity. They are aggregates of minerals, more or less closely cohering, each of which possesses degrees of expansion and con- traction of its own. In the crystalline rocks these dissimilar elements are practically in actual contact ; in the sandstones they are removed from one another by a slight space occupied wholly or in a part by a ferruginous, calcareous or siliceous cement. As temperatures rise, each and every constituent ex- pands more or less, crowding with resistless force against its neighbor : as the temperatures decrease a corresponding con- traction takes place. Since with us the temperatures are ever changing, and within a space of even twenty-four hours may vary as much as forty degrees, so within the mass of the stone there is continual movement among its particles. Slight as these movements may be they can but be conducive of one result, a slow and gradual weakening and disintegration. This constant expansion and contraction is often sufficient in amount to be appreciable in stone structures of considerable size. Thus Bunker Hill Monument, a hollow granite obelisk, 221 feet high by 30 feet square at the base, swings from side to side with the progress of the sun during a sunny day, so that a pendulum suspended from the centre of the top describes an irregular ellipse nearly half an inch in greatest diameter.* Under such circumstances as these it is not at all strange * Dana, Manual of Geology, p. 720. 354 STONES FOR BUILDING AND DECORATION. that many stones show a decided weakening and tendency to disintegration after long exposure, and particularly on those sides of buildings exposed longest to the sun, and which are, therefore, subject to the full range of temperature variations. Professor Julien has called attention to the marked decay thus produced on the western face of the tombstones in Trinity church-yard and elsewhere. It is stated further that the ashlar base of the steeple of the church at Thirty-seventh Street and Fifth avenue, New York City, is beginning to exfoliate from this cause on the south side (where the sun shines the longest) but not on the north and east. Other examples are seen on the stone stoops of the east and west streets, where the western face of the dark-brown sandstone is badly disinte- grated and exfoliated, while the eastern face remains much longer in a perfect condition. The author has observed similar effects, but in a less marked degree, on the Smithsonian build- ing, at Washington, D. C. The south and west sides fre- quently show exfoliation, while the north and east, upon which the sunshines but a small portion of the day, r.re almost untouched. This same expansion and contraction of stone sometimes produces disastrous effects other than those of disintegration within its own mass. The difficulty of obtaining permanently tight joints even with the strongest cements led Colonel Totten to institute a series of experiments with a view to ascertain the actual ex- pansion and contraction of granite, sandstone and marble when subjected to ordinary temperatures. Upwards of thirty experiments on each of these varieties of stone showed the rate of expansion and contraction, which seemed to be uni- form throughout the range of temperatures employed, to be for granite .000004825 inch per foot each degree Fahren- STONES FOR BUILDING AND DECORATION. 355 heit : for marble .000005668 inch, and for sandstone, .000009532 inch.* Supposing, then, two coping stones each five feet long be laid in midsummer at a temperature of 96 Fahr. In winter the temperature falls to zero, a change of 96. If the stones contract toward their centres, the whole length of stone put in motion will be five feet. In the case of granite, then, the shrinkage amounts to .027792 inch, in marble .03264 inch, and in sandstone to .054914 inch. This shrinkage, small as it seems, from necessity gives rise to cracks at the joints, which admit the passage of water ; continual shrinkage and expansion must in time crumble the cement and leave the joint permanently open.f The effects of moderate temperatures upon stone of ordin- ary dryness are, however, slight when compared with the de- structive energies of freezing temperatures upon stones saturat- ed with moisture. At a temperature of 30 Fahr. the pres- sure exerted by water passing from a liquid to a solid state amounts to not less than 138 tons to the square foot, or as Professor Geikie has strikingly put it, is equal to the weight of a column of ice a mile high. It is therefore not surprising that a porous sandstone exposed in a house-front to be saturated by a winter's rain and then subjected to temperatures perhaps several degrees below the freezing point shows signs of weak- ness and exfoliation after a single season's exposure. Indeed the injurious effects produced by the freezing of stone, and particularly sandstone, when freshly quarried and saturated with water, have long been recognized by quarriers, who refuse * Adie found the rate of expansion for granite to be .00000438 inch, and for white marble, .00000613 in. Transactions Royal Society of Edinburgh, xm. p. 366. f W. H. C. Bartlett on Contraction and Expansion of Building Stone, American Journal of Science, vol. xxn. 1832, p. 136. STONES FOR BUILDING AND DECORATION. to assume any risk from such freezing after the stone is deliv- ered for shipment. In the northern and New England States quarrying, as a rule, ceases on the approach of the cold season, owing in part to the liability to injury of the freshly quarried material, and when expedient it is often customary to flood the quarries with water ; if left unprotected there is always a considerable loss of surface stone due to its having frozen and burst, or at least become shaky. (See remarks on time of quarrying, p. 383.) The injurious effects of artificial heat, such as is produced by a burning building, are, of course, greater in proportion as the temperature is higher. Unfortunately sufficient and reliable data are not at hand for estimating accurately the comparative enduring powers of various stones under these trying circum- stances. It seems, however, to be well proven that of all stones granite is the least fire-proof, while the fact that certain of the fine-grained siliceous sandstones are used for furnace backings would seem to show that if not absolutely fire-proof, they are very nearly so.* * Cutting's experiments ("Weekly Underwriter") showed that up to the point at which they are converted into quicklime, limestones are less injured by heat than either granite or sandstones (a result not fully borne out by the experi- ments of Winchell, Geology of Minnesota, vol. i, p. 197-201). According to this authority the heat resisting capacity of building-stones, when water is not applied, stands somewhat in the following order : i, Marble ; 2, Limestone ; 3, Sandstone ; 4, Granite ; 5, Conglomerate. In Dr. Cutting's own words, "The limestones and marbles seldom crack from heat or water, but when heat from the outside is excessive, they slightly crumble on the outside, if water is thrown on them. When they are cooled without the application of water, the injury is much less." " The specimens tested stood fire well, as a whole, up to the temperature of heat necessary to convert them into quicklime, apd at such a heat, if long con tinued, they are changed so as to slake off and crumble down. In most cases this heat is greater than 900 degrees (Fahrenheit), and in some cases beyond 1,000 degrees." STONES FOR BUILDING AND DECORATION. 357 It must be remembered, however, that the sudden cooling of the surface of a heated stone, caused by repeated dashes of cold water, has often more to do with its disintegration than heat alone. Effects of friction. The amount of actual wear to which stones in the walls of a building are subjected is naturally but slight in comparison with those in the sills, steps, and walks, which are subject to the friction of feet and other agencies. Nevertheless it is sufficient in many cases to become apprecia- ble after the lapse of several years. The striking effect pro- duced by wind-blown sands in the Western States and Terri- tories has often been alluded to* and even in the Eastern States, as at Cape Cod, Massachusetts, there may frequently be seen window-panes so abraded by blowing sand as to be no longer transparent, f This same abrading process is going on in all city streets, where the wind blows dust and sand sharply against the faces of the buildings ; not with sufficient force, it may be, to per- ceptibly wear away the fresh stone, but yet forcibly enough to crumble away the small particles already loosened by atmos- pheric decomposition and thus expose new surfaces to be acted upon. Professor Egleston^: states that in many of the church- yards of New York City the effects of this abrasive action can be seen where the stones face in the direction of the prevailing winds. In such cases the stones are sometimes * On the Grooving and Polishing of Hard Rocks and Minerals by Dry Sand. W. P. Blake. Proceedings American Association for the Advancement of Science, Providence meeting. f There is on exhibition in the National Museum a plate of glass formerly a window in the light-house at Nauset Beach, Massachusetts, that was so abraded by wind-blown sand during a storm of not above forty-eight hours' duration as to be no longer serviceable. The grinding is as complete over the entire sur- face as though done by artificial means.. \ American Architect, Septembers, 1885, p. 13. STONES FOR BUILDING AND DECORATION. worn very nearly smooth and are quite illegible from this cause alone. Effects of growing organisms. It is in such exposed situa- tions as those above mentioned that a stone is often protected from serious loss by a coating of lichens or mosses, which by growing over its surface shield it from the abrasive action. The full effect of growing organisms upon the surface of stones is still, however, a matter of dispute. By some authorities * it is thought that they give rise to small amounts of organic acids which exercise a corrosive influence. By others they are con- sidered as beneficial, since they protect the stone from the sun's rays and the rain and wind. It seems probable that they may exert either a harmful or beneficial action according to the kind of stone on which they grow and its environment. More observations are necessary before anything definite can be said.f * See Winchell, Geology of Minnesota, vol. i. p. 188. f The vegetation f microscopic lichens takes place upon the surface of the stone, when, from any cause, that surface becomes roughened so as to afford a lodgment for th' seeds or spores of these plants. These growing, still further hasten the disintegration of the stone, and accumulating about them the fine dust floated by the atmosphere becomes points for the absorption of more water, which, on freezing, still further roughens the surface, and the patch of lichen gradually extends. These lichens often gain attachment upon the sur- face of a finely dressed stone, from some little inequality of texture, or from softer material that more readily becomes decomposed or more readily accom- modates the growth of the plant. Such stones in time become partially or en- tirely covered by lichens, and present an unsightly aspect. The amount and degree of this growth varies with position in reference to the sun and with a more or less elevated situation. It should not be forgotten, however, that any stone giving root to lichens is not one of those which most easily disintegrates, for in these the destruction goes on so rapidly that the surface does not allow the growth of such plants. The lichen-covered rocks in nature are usually those of great strength and dura- bility. None of the softer or rapidly decaying rocks produce this vegetation. (Report on Building Stones by James Hall, 1868, pp. 54 and 55.) STONES FOR BUILDING AND DECORATION. 359 (2) CHEMICAL AGENCIES. Composition of the atmosphere. The atmosphere in its nor- mal state consists of a mechanical admixture of nitrogen and oxygen in about the proportions of four, volumes of the former to one of the latter, together with minute quantities of carbonic acid, ammonia, and vapor of water. In the vicinity of large manufacturing cities, however, it carries in addition to increased proportions of carbonic acid,* appreciable quantities of sulphur- ous, sulphuric, nitric, and hydrochloric acids.f These, when brought by rains into contact with the walls of buildings, are capable, throughout many years of time, of producing marked effects, especially when aided by the extreme diurnal ranges of temperature common in the eastern and northern United States. * Twenty -one tests of the air in various parts of Boston during the spring of 1870 yielded Mr. Pearson 385 parts of carbonic acid in 1,000,000. Eleven tests of the winter air at Cambridge yielded Mr. Hill 337 parts of the acid in 1,000,000 (Second Annual Report Massachusetts State Board of Health, 1871, p. 52). Dr. Kidder found the outdoor air of Washington to contain from 387 to 448 parts in 1,000,000. Mr. Agnus Smith (Air and Rain, p. 52), after an elaborate series of experiments, reports the air of Manchester (England) to contain on an aver- age 442 parts of the acid in 1,000,000. f Dr. Smith (pp. cit.) found the proportions of these acids in London, Liver- pool and Manchester to be as follows : Localities. Sulphuric. Hydrochloric. Nitric. Grains per gallon. Parts per million. Grains per gallon. Parts per million. Grains per gallon. Parts per million. London Liverpool 1-4345 2.7714 2.9163 20.49 39-56 41.66 .0872 . 7110 4SS 1.250 10. 16 5-79 1! Manchester He also found the total acids for Manchester to average for 1870 3.7648 grains per gallon. It should be noted, however, that these acids were not considered 360 STONES FOX BUILDING AND DECORATION. Chemical action of the atmosphere. The series of changes in- duced by these agencies are, as above indicated, chemical in their nature and may all, as first suggested, be conveniently grouped under the heads of oxidation, deoxidation, hydration, and solution. These may as well be considered in the order given. Oxidation. The process of oxidation is commonly confined to those stones which carry some form of iron as one of their constituent parts. If the iron exists as a sulphide (pyrite or marcasite), it very probably combines with the oxygen of the air on exposure, forming the various oxides and carbonates of iron such as are popularly known as " rust." If the sulphide occurs scattered in small particles throughout a sandstone the oxide is disseminated more evenly through the mass of the rock, and aside from a sight yellowing or mellowing of the color, as in certain of the Ohio sandstones, it does no harm. Indeed as suggested by Professor Winchell,* it may result in positive good, by supplying a cement to the individual grains, and thus increasing the tenacity of the stone. In all other than sandstones, however, the presence of a readily oxidizable sulphide is a serious defect, since crystalline rocks require no such cement, and the change in color can in very few cases be as existing in the atmosphere entirely in an uncombined state, but were proba- bly in large part combined with other substances to form chlorides, sulphates, etc. L. P. Gratacap (School of Mines Quarterly, May, 1885, p. 335), from a series of tests at Staten Island, New York, computed the entire amount of chlorine brought down by the rains during 1884 to have been some 46.23 pounds for each acre of ground. This is regarded as in large part combined with sodium to form sodium chloride (common salt). Egleston ("Cause and decay of Building Stone," p. 5) estimates that the 4, 500,000 tons of coal annually burnt in New York City discharge into the air 78,750 tons of sulphuric acid. In 65 cubic centimeters of rain-water caught during an exposure of forty-one days, this same authority found 4^ milligrams of sulphuric acid. * Geology of Minnesota vol. i. p. 189. STONES FOR BUILDING AND DECORATION. 361 considered other than a blemish. This is well illustrated in some of the lower courses of granite in the new capitol build- ing at Albany, New York, to which reference has already been made. More than this, the pyrite, in decomposing in contact with the gaseous atmosphere of cities, may give rise to small quantities of sulphurous and sulphuric acids, which by their corrosive action upon the various mineral constituents of the stone may give rise to efflorescent magnesian salts, besides ren- dering it porous and more liable to the destructive effects of frost. (See p. 31.) The conversion by oxidation of a sulphide into a sulphate is moreover attended with an increase in vol- ume ; there is thus brought to bear a mechanical agency to aid in the work of disintegration. Iron in the form of ferrous carbonate is a common constitu- ent of many calcareous rocks, and in the form of this and other readily decomposable protoxide compounds occurs not infre- quently in the cementing material of fragmental rocks lying below the water level. All these compounds are susceptible to oxidation on exposure to atmospheric influences, and to these, more than to the presence of sulphides, is presumably due the mellowing commonly observed in white marble or the light gray sub-Carboniferous sandstones. Iron, in the form of magnetite a mixture of the ferrous and ferric oxides is liable to hydration and still further oxi- dation, becoming converted wholly into the hydrous or anhy- drous ferric oxide. Thus, if abundant, the rock assumes a rusty hue, and perhaps gradually falls away to a coarse sand, as is the case with certain of our diabases.* * " In one part of the dikes that form the Hanging Hills at Meriden, Con- necticut, the rock (diabase) is quite black, and the amount of iron (nearly 14 per cent of magnetite) has been the cause of rapid disintegration." Hawes, Amer- ican Journal of Science, vol. IX. 3d, 1875, p. 188. 362 STONES FOR BUILDING AND DECORATION. Black mica, hornblende, augite, and other silicate minerals rich in iron are also liable on long exposure to change through the further oxidation of this ingredient, but when a stone is placed high and dry, as in the walls of a building, this change must necessarily be so slow as to be of little moment, though of the greatest importance from a geological standpoint. Mr. Wolff, however, states * that tombstones of diabase in ceme- teries about Boston have in some cases turned a rust-brown color, the change apparently occurring in the hornblende and augite. The feldspars of the granites used in this same city were also observed in many cases to have become liver-brown, rusty-red, or yellow owing to the higher oxidation of the iron contained by them. Deoxidation. The process of deoxidation, whereby a ferric is changed to a ferrous oxide, is possible generally only in pres- ence of organic acids and continual moisture. It is likely, therefore, to affect only those stones used for foundations, and need not be further considered here. The same may be said in regard to hydration, whereby an anhydrous is changed to a hydrous oxide. The blotching and variegation of beds of sand- stone, as those of Marquette, Michigan, is due presumably to the deoxidation and hydration of the iron oxides forming their cement, together with a partial removal of the same by the aid of organic acids. Such changes are possible only in the quarry bed or in moist foundations and bridge abutments. Solution. The subject of solution can not, however, be passed over so lightly. Pure water alone is practically without effect on all stones used for building purposes. Rain-water, however, as already noted, may contain appreciable quantities of various acids which greatly add to its solvent power, as the rapijd destruction of certain classes of rocks only too well at- * Report, Tenth Census, vol. x. STONES FOR BUILDING AND DECORATION. 363 tests. Carbonate of lime, the material of ordinary marbles and limestones, is particularly susceptible to the solvent action of these acids even when they are present in extremely minute quantities, and to this agent is largely due the rapid deface- ment of the marble tombstones in church-yards, and the mar- ble-faced buildings in cities. It is to the ready solubility of calcium carbonate that is also due in large part the poor weathering qualities of sandstones with calcareous cements. The cement is slowly removed by solution ; the silicious grains thus become loosened, and, falling away under the influence of wind and rain, expose fresh sur- faces to be acted upon. Certain of the ferruginous cements are likewise susceptible to the influence of the acidulated rains, though the anhydrous oxides occurring in the Potsdam stones are naturally less soluble than are the hydrated forms occur- ring in those of Triassic age. The feldspars of granites and other rocks are also susceptible to the same influence, though in a much less degree. The acidulated rains aided by the dis- integration produced by temperature changes may in time par- tially remove, in the form of carbonates, the alkalies potash and soda and the rock slowly disintegrates into sand and clay. The feldspars of the gneiss, used so extensively in years past in and about Philadelphia, are said to have proved peculiarly liable to this change, and it has been found necessary in many instances to paint some of the older structures formed from it to avoid serious disintegration. (3) INDURATION OF STONE ON EXPOSURE. The changes produced by weathering are not in all cases those of decomposition. All stones, and especially the lime- stones and sandstones, undergo at first a process of hardening on being removed from the quarry or when exposed in the 364 STONES FOR BUILDING AND DECORATION. quarry bed, as will be noted further on. This hardening is explained by Newberry and others on the supposition that the water with which the stones are permeated, holds in solution, or at least in suspension, a small amount of siliceous, calcare- ous, ferruginous or clayey matter. On exposure to the atmos phere this quarry water, as it is technically called, is drawn by capillarity to the surface of the block and evaporated. The dissolved or suspended material is then deposited, and serves as an additional cementing constituent to bind the grains more closely together. It is obvious that the amount of induration must in most cases be quite small, and limited to but a thin outer crust on each block ; also that when this crust has once formed it can, if removed, never be replaced since the stone in the walls of a building is cut off from further supply of quarry water, and as a matter of course, after whatever quantity con- tained within its own mass has come to the surface and evapor- ated, no further hardening by this means can take place.* It is on this account that the practice of setting rough stone in a wall, and leaving them to be carved when the struct- ure is completed, is strongly condemned by some, f as in so doing the hard outer crust that began to form as soon as the stone was exposed to evaporation is entirely removed, and the delicate carving disintegrates much more rapidly than other- wise would have been the case. The carving, it is argued, * This induration sometimes takes place in a peculiarly rapid and interest- ing manner. Dr. Wadsvvorth, in writing on some Potsdam and St. Peter's sandstones near Mazo Manic, Wisconsin, states that those portions of the stone which are exposed to atmospheric influences have become by induration converted into compact quartzites, while the protected portions still retain their porous and friable nature. So rapidly does this change take place that an ex- posure of but a few months is sufficient to produce very marked results on a freshly broken surface. Proceedings Boston Society of Natural History, voL xxii. 1883, p. 202. f Le Due, " Story of a House," p. 143. STONES FOR BUILDING AND DECORATION. 365 should be done at once, while the quarry water is still present ; the crust then forms upon its surface, and it is thus better able to resist atmospheric action. The rescouring and honing of buildings and works of art is strongly objected to on similar grounds.* (4) WEATHERING PROPERTIES OF STONES OF VARIOUS KINDS. Let us now consider the effects of the various agencies just enumerated upon the different classes of rocks in common use for building materials. Granites are liable to disintegration chiefly from the con- stant expansion and contraction caused by natural tempera- tures. The chemical changes to which they are subject, such as the kaolinization of the feldspars or rusting of the micas, being as a rule scarcely noticeable in the walls of a building, while they are so compact as to be practically non-absorbent and hence not liable to injury by freezing alone. The same may be said respecting the diabases, melaphyrs, and basalts when not particularly rich in magnetite or secondary calcite. Dr. Hague, in describing the decay of the granite obelisk in Central Park, New York, says: " In my opinion the process of disintegration has been an extremely slow one, caused by a constant expansion and contraction of the constituent minerals near the surface, due to diurnal variations of temperature. In a climate like that of New York, where these diurnal changes are frequently excessive at all times of the year, the tension between the minerals would naturally tend to a mechanical disintegration of the rock. Granite being a poor conductor of heat, the effect of these changes would be felt only at short distances below the surface, causing in time minute fractures * See Chateau, under " Inconvenience du grattage a vif," p. 353. 366 STONES FOR BUILDING AND DECORATION. and fissures along lines of weakness. Into these openings per- colating waters, upon freezing, would rapidly complete the work of destruction."* Helmerson explains the rapid disintegration of the Alex- ander column in St. Petersburg, Russia, on the grounds that it contains many large crystals of a triclinic feldspar, which when subjected to the extreme temperatures of Russian climate expand and contract unequally in the direction of their three crystallographic axes and hence cause the crumbling. f This view seems plausible, but we believe it yet remains to be shown that rocks rich in triclinic feldspars in reality disintegrate more rapidly than others. Granite was for a long time popularly believed to be a nearly fireproof material. The great fires of Portland, Boston, and Chicago not merely exposed this delusion but proved the direct opposite that instead of being the most fire-proof it was the least so, ranking below either sand- or limestone. The peculiar susceptibility of the stone to the effect of heat may be ascribed to its compact and complex structure, each of its constituent minerals possessing different degrees of expan- sibility.^: * Science, December 11, 1885, p. 511. f See Science, January 22, 1886, p. 75. ^ The co-efficient of cubical expansion for several of the more common rock- forming minerals has been determined as follows : Quartz 000036 Orthoclase 000017 Adularia (feldspar) 0000179 Hornblende 0000284 Beryl oooooi Tourmaline 000022 Garnet 000025 Calcite 00002 Dolomite , . . . .000035 The quartz, it will be noticed, has a co-efficient of expansion double that of the orthoclase, and nearly a third greater than hornblende. The matter is further complicated by the fact that each individual mineral expands unequally along the direction of its various axes. Thus quartz gives a co-efficient of STONES FOR BUILDING AND DECORATION. 367 It has also been suggested by certain authors that the minute water-filled cavities in the quartz of these rock may be an important factor, since, when highly heated, the water is. converted into steam and an explosion results, causing the quartz to fly into fragments. After microscopic examination of a very large number of our granites the writer can but feel that the results thus produced are too small to merit serious consideration. The relative durability of sandstone and granite under fire is stated to have been well shown not long since at the burning of St. Peter's Church at Lamerton, England. The church itself, which was built in great part of granite, was completely ruined, while the tower, built of a local freestone, around which the heat of the fire was so great as to melt six of the bells as they hung in the belfry, was left intact, although the granite window-jams and sills were destroyed.* Limestones and dolomites, both marbles and the common varieties, are perhaps less affected than granite by the purely mechanical agencies, but make up for this in their susceptibility to the solvent ^action of gaseous atmospheres. Limestones are in this respect less durable than dolomites, so that, the tenacity being the same, a dolomite might, under the same circum- stances, be considered as promising greater durability than a limestone (see p. 381). A thoroughly crystalline or non-crys- talline compact and homogeneous limestone or dolomite is scarcely, if any, more absorbent than a granite, and hence it is as little liable to injury from freezing. Professor Geikie, in .00000769 parallel to the major axis, and of .00001385 perpendicular to this axis; adularia gives .0000156, .000^000659, and .000,00294 for its three axes; and hornblende for the same axes gives .0000081, .00000084, and .0000095. (See Clarke's "Constants of Nature," Smithsonian Miscellaneous Collection, vol. xiv.) * American Architect, vol. iv. 1878, p. 80. 368 STONES FOR BUILDING AND DECORATION. studying rock-weathering, as displayed by the marble tomb- stones in Scottish cemeteries, observed that the process pre- sented three distinct phases, all of which were at times observ- able on the same slab. These were (i) superficial solution, caused by the carbonic and sulphuric acids of the atmosphere ; (2) internal disintegration, accompanied or preceded by the formation of an exterior coat or film of sulphate of lime ; and (3) curvature and fracture. The first phase manifested itself in loss of polish and gradual roughening of the surface, fol- lowed by the formation of minute rifts and final rapid disin- tegration. One case is mentioned in which a stone erected in 1785 became so far decayed as to require restoration in 1803, and at the time of writing (1880) was and had been for some years so corroded as to be entirely illegible. The second phase, that of internal disintegration, mani- fested itself in a peculiar manner. In a number of cases exam- ined it was found that the sulphuric acid brought in contact with the stone by rains had reacted upon the calcium carbon- ate, producing a superficial coating, varying in thickness from that of a sheet of paper to a millimeter, of sulphate of lime. This, so long as it remained intact, seemed to protect the stone from other atmospheric influences. On the breaking of the crust, however, it was found that the cohesion of the crystal- line granules beneath had been destroyed and the stone crum- bled rapidly to sand, the cause of which is attributed largely to mechanical agencies. The third phase, that of curvature and fracture, was ob- served only on thin slabs of marble, which had been placed in a horizontal or vertical position and confined by a frame of sandstone. It manifested itself in the bulging outward of the slab like the bellying of a well-filled sail. In one case exam- ined, that of a slab of marble 305- inches long, 22| inches wide, by three-fourths of an inch thick, which had been thus secured STONES FOR BUILDING AND DECORATION. 369 against a wall, the slab was found to have escaped from its fastenings at the sides, though still held at the top and bottom, and to have bulged outward sufficiently to allow the insertion of the hand and arm between it and the wall at the widest point. It had also expanded laterally so as to be one-half an inch wider in the center than at the ends. The outer surface of the slab where the greatest strain was produced by the bend- ing was filled with minute cracks or rifts, the largest of which were some one-tenth inch in diameter. The cause of the bulg- ing is believed by Professor Geikie to be due to expansion caused by the freezing of water absorbed from rains. The conclusions arrived at from the examination of a large number of cases, were to the effect that in all but exceptionally favor- able and sheltered localities slabs of marble exposed to the weather in such a climate as that of Edinburgh lost their polish after an exposure of but a year or two and became entirely destroyed in less than a century ; hence that the stone was quite unfitted for outdoor work in that vicinity.* These results are greatly in exaggeration of what takes place in our own cemeteries. Professor Julien states that in the city cemeteries about New York the polish on marble tombstones often survives for ten years, and, in protected places, as near the ground in suburban cemeteries, for half a century. He further states that while of the tombstones in St. Paul's churchyard in New York City, about one-tenth of the inscriptions dating back to the latter part of the eighteenth century are illegible, he has never seen the same effect produced in suburban cem- eteries in the same length of time. The author's own obser- vations on the subject are to the effect that in the cemeteries of the smaller towns and cities of New England marble tomb- stones will retain their polish for a period of ten or fifteen years, * Geological Sketches, pp. 170-172. 37 STONES FOR BUILDING AND DECORATION. and up to thirty or thirty-five present no sign of disintegration of a very serious nature. Beyond this time, however, the sur- face becomes rough and granular, and the edges of the stone may be found filled with fine rifts into which particles of dirt become lodged or lichens take root, giving it a dirty and unkempt appearance.* Such stone are frequently taken down, rehoned and polished, and again set up to do duty for another term of years. A closely crystalline or non-crystalline, compact and homo- geneous limestone is probably as little affected by frost as are the granites. Very many of the limestones and dolomites used for ordinary building are, however, by no means suf- ficiently non-absorbent to protect them from injury by freezing, nor are they sufficiently uniform in texture to weather evenly, the disintegration going on more rapidly in some layers than others, thus producing rough and unsightly walls. Professor Winchell, writing on the weathering of the Trenton limestone used at St. Paul and Minneapolis says : f " The stone itself has an attractive and substantial aspect when dressed under the hammer, the variegations due to the alternating shaly and limy parts giving the face a clouded appearance, as of gray marble, without being susceptible of a uniform polish. Where pro- tected from the weather the shale will endure and act as a strong filling for the framework of calcareous matter for a long time ; but under the vicissitudes of moisture and dryness, and of freezing and thawing, it begins to crumble out in a few years. This result is visible in some of the older buildings, both in St. Paul and Minneapolis." Professor Hall, writing on rock weathering,^ says : " In the gray or bluish-gray sub- * The fine-grained saccharoidal marbles, used for statuary are even less durable, and in extreme cases have shown serious disintegration at the end of three or four years' exposure. f Preliminary Report on Building-stones, etc., 1880, p. 13. $ Report on Building-stones, p. 36. STONES FOR BUILDING AND DECORATION. 371 crystalline limestones the argillaceous matter, instead of being distributed throughout the mass, is usually present in the form of seams which are parallel to the lines of bedding or distrib- uted in short, interrupted laminae. These seams, whether con- tinuous or otherwise, are fatal to the integrity of the stone, and there is scarcely a limestone structure in the country, of twenty-five years standing which is not more or less dilapi- dated or unsightly, from the effects of absorption of water by the clay seams, and the alternate freezing and thawing. When laid in the position of the original beds, which is the usual mode, the separation by the clay seam is slower ; but when used as posts or pillars, with the lines of bedding vertical, the change goes on more rapidly." Sandstones, on account of their widely varying textures and degrees of compactness, together with an equal variation in composition and character of cementing materials, are influ- enced, to a greater or less extent, by all the atmospheric influ- ences enumerated. In the order of its apparent importance may be mentioned first the effects of freezing. As will be no- ticed by reference to the tables in the appendix, sandstones will absorb from about one-fiftieth to one-eighth of their weight in water in twenty- four hours, or from 2 per cent to I2J- per cent. The approximate amount which a stone may absorb with impunity cannot, of course, he stated, since much depends on its position in a building and the strength and structure of the stone itself. It is not too much to say, however, that any stone which will absorb 10 per cent of its weight of water dur- ing twenty-four hours should be looked upon with suspicion until, by actual experiment, it had shown itself capable, of withstanding, without harm, freezing when in this condition. Half of this amount may be considered as too large when the stone contains any appreciable amount of calcareous or clayey matter. (See p. 387, also foot-note on p. 379.) 372 STONES FOR BUILDING AND DECORATION. It is to their great absorptive power that is due the large amount of disintegration and exfoliation seen in the softer sandstones, as the Triassic of the eastern United States and the sub-Carboniferous of Ohio. When a stratified rock, and especially one that is distinctly laminated, is placed on edge the water filters into it from above, and, there freezing, from necessity produces the scaling so often noted in the Connecti- cut brownstones. If placed on the bed the effect is not nearly as disastrous, but with a porous stone the effect of continual freezing and thawing can but be injurious. It was with an apparent entire disregard of the probable effect of these agen- cies that was selected the soft and porous Juro-Cretaceous sandstone from Acquia Creek, Virginia, for the construction of the White House, central part of the Capitol, and other public and private buildings in Washington, a stone so susceptible to these influences, that it is only by a most prodigal use of paint and putty that the buildings are kept in a condition at all presentable.' 55 ' Acid gases are naturally without effect upon the silicious particles of a sandstone, and can be productive of injury only in dissolving out the ferruginous and calcareous cements. This is actually accomplished in many cases, and much disin- tegration results as a consequence. Indeed, Egleston * seems * Other reasons than that of lack of durability can be given against the use of a too porous stone in a house wall. " A red sandstone house may be a very handsome building, but then it may be holding tons of water, and such a wall, if exposed to the north-west, in an open country, in our neighborhood, in a rainy winter, would, no doubt, get saturated. This means expending more fuel to convert part of this water into vapor. The difficulty is surmounted to a great extent by building hollow walls, the inner wall being of brick. Woe unto the man who has not taken this precaution." (T. Mellard Reade, in Proceedings Liverpool Geological Society, p. 445 and 446, i883-'84.) f Cause and Prevention of Decay in Building-stone. Transactions American Society Civil Engineers, xv. 1886. STONES FOR BUILDING AND DECORATION. 373 to regard the serious decay into which the stone of Trinity Church, New York, has fallen, to be due chiefly to this cause, supplemented by the action of frost after the cement had been removed and the stone thus rendered porous. The relative solubility of the various ferruginous cements has been always alluded to (ante, p. 363). Oxidation is likely to play a more noticeable part in sandstones than in most other rocks, owing to their porous nature, which allows ready access of water and air. The effects of oxidizing pyrite and ferrous carbonates in producing the .mellowing and other color changes in stones of this class is sufficiently dwelt upon elsewhere, as is also the effect of heat, both natural and artificial. On account of their porosity and natural roughness of sur- face sandstones are of all stones most likely to afford foothold for the growth of algae, lichens, and mosses. While it is yet to be proved that these are actually injurious, they are at least suggestive of an unhealthy dampness. A stone once covered by these organisms will absorb more water and give it up more slowly to evaporation than one whose surfaces are not thus protected. Serpentines when free from bad veins are as a rule non-ab- sorptive and not affected by gaseous atmospheres, hence are durable if free from bad joints. The Pennsylvania serpentines sometimes fade or turn whitish on exposure, but so far as ob- served do not disintegrate. Soapstone, although too soft and possibly too slippery for general building, is nevertheless one of the most durable stones, being not only proof against atmospheric and chemical agen- cies, but when well seasoned fire-proof as well. Gypsum is too soft and too soluble in ordinary terrestrial waters to be of great value. 374 STONES FOR BUILDING AND DECORATION. ON THE SELECTION AND TESTING OF BUILDING STONE, (l) GENERAL CONSIDERATIONS. From what has gone before it must be evident that there are many more factors which go to determine the value of stone for structural purposes than are ordinarily taken into consideration. It may therefore not be out of place here to mention a few general principles to be observed in selecting stone for any purpose in which durability, or stability of color are matters of importance. It should be stated at the outset that the problem of ascertaining by laboratory or other tests the actual qualities, good or bad, of any stone, is peculiarly complicated and difficult.* In the present state of our knowl- edge nothing like definite rules of procedure with any proba- bility of accurate and reliable results can be given. That the difficulties may be better appreciated it may be well to note here the main points to be considered. In the order of their apparent importance they are : (1) Resistance to changes in temperature. (2) Resistance to chemical action of the atmosphere. (3) Crushing strength and elasticity. (4) Resistance to abrasive action of feet and wind-blown sand. The order as above given may be subject to modification to suit individual cases. In many instances the actual strength of a stone is a matter of little importance, and in protected sit- uations the quality mentioned under (4) maybe left wholly out of consideration. In still other cases, as in bridge abutments, * See article " On the Testing of Building-stone," by the writer, in American Architect for Februar} 16, 1889. S7VNES FOR BUILDING AND DECORATION. 375 strength and elasticity are matters of greatest import, while that of change of color can have no essential value. In the arrangement given above, especial regard has been had to stone exposed in the exterior walls of a building, and in a varied climate like that of the northern and eastern United States. The first item for consideration is then the matter of cli- mate. This, together with the location in which a structure is to be erected, with especial reference to proximity to large cities and manufacturing establishments, and even the direc- tions of the prevailing winds and storms, are of primary im- portance and need consideration as well as do the physical and chemical properties of the stone itself.* Our Northern and Eastern States, with an annual precipi- tation of some thirty-nine or forty inches and a variation in temperature amounting in some cases to not less than 120, are necessarily more trying than those where the precipitation is less or the temperature more uniform. There is many a por- ous sand- or limestone which could endure an exposure of hun- dreds of years in a climate like that of Florida or New Mexico, * " As an instance of the difference in degree of durability in the same ma- terial subject to the effects of atmosphere in town and country we may notice the several frustra of columns and other blocks of stone that were quarried at the time of the erection of St. Paul's Cathedral in London, and which are now lying in the island of Portland, near the quarries from where they were ob- tained. These blocks are invariably found to be covered with lichens, and al- though they have been exposed to the vicissitudes of a marine atmosphere for more than one hundred and fifty years they still exhibit beneath the lichens their original forms, even to the marks of the chisel employed upon them, whilst the stone which was taken from the same quarries and placed in the cathedral itself is in those parts xvhich are exposed to the south and south-east winds found in some instances to be fast moldering away." (Gwylt's Encyclopaedia, of Archi- tecture p. 458.) It is stated that in England the northern part of a building is always in a better state of preservation than the southern, owing to the more uniform amount of moisture and less heat from the sun. STONES FOR BUILDING AND DECORATION. but which would probably be found in a sad state of disinte- gration at the end of a single season in some more northern State. We are accustomed to hear a great deal regarding the wis- dom of the ancients, and especially the Egyptians, as shown in the selection of enduring materials for their obelisks and monu- ments,* a wisdom or prudence which modern builders "admire more than they imitate," and we are referred to the still legible inscriptions and sharp sculptures on the surfaces of these obelisks, even after thousands of years of exposure, as proof of this marvellous foresight on the part of a semi-barbarous people. It must be borne in mind, however, that nature herself had vastly more to do in this matter than Egyptian foresight, and it is more than probable that at that time materials were select- ed with as little knowledge of their lasting qualities as they are to-day. The Syene granite, so durable under Egyptian skies, is no better than those in common use in this country, as the transported obelisks in New York and London have plainly shown. It is a matter of climate more than of mate- rial, and this fact should never for a moment be ignored. Were the climate of the United States like that of Egypt, southern Italy, or Mexico there would have arisen no occasion for the compilation of this chapter.f * Vide " Materiaux de Construction," par L.^ftlal&LQt, p. 30. f " From the manner in which the buildings and monuments of Italy, formed Of calcareous materials, have retained to a wonderful degree the sharpness of their original sculpturing, unless disfigured by the hand of man, it is clear that a dry and smokeless atmosphere is the essential element of durability. In this respect, therefore, the humid sky and gaseous atmosphere of British towns must always place the buildings of this country at a comparative disadvantage as regards durability." (Hull, p. 282.) " La Grece, la Basse-Italic, et notamment la Sicile, dit il, ont cet etrange privilege que tout s'y conserve intact, presque sans se deteriorer, pendant des siecles consecutifs. Aussi les monuments, les statues, les marbres blancs eux- STONES FOR BUILDING AND DECORATION. 3/7 (2) PRECAUTIONS TO BE OBSERVED. The precautions which should be observed in selecting a stone for building purposes may here be briefly noted. In those portions of the northern and eastern United States that have been subjected to glacial action,* and where the great mass of rotten rock that had accumulated during previous geologic ages has been entirely removed, if the surface of the rock as displayed in the quarry or natural outcrops presents a fresh and undecomposed appearance, this may be construed as a strong argument in its favor, though it can not in all cases be accepted as conclusive.f A purely calcareous rock may memes, qui, chez nous (en France), deviennent noirs en deux ans, rouges en dix ans, ruines en cinquante, chez eux sont a peine noircis au bout de trois ou qua- tre siecles d'exposition en plein air. Sous terre oudans un appartement ils gar- dent intactes leur forme et jusqu'aleur blancheur, perpetuite pour ainsi dire. " J'ai vu retirer de terre a Pouzzoles, pres de Naples, des marbres enfouis de- puis plus de deux mille ans, qui avaient 1'air de sortir des mains du sculpteur. " A Palerme, les statues et les marbres en plein air sont, il est vrai, assez noirs; mais ils n'ont jamais ete touches, m'a-t-on dit, depuis leur mise en place, et il y a la des statues qui datent de dix siecles." (E. Carrey, as quoted in Malecot's Materiaux de Construction, p. 31.) * This includes all of New England and those portions of other States lying north of a line running irregularly from a point near the western end of Long Island across New Jersey ; thence northwesterly across Pennsylvania into New York State south of Buffalo ; thence southwesterly to near central Ohio ; thence due south nearly to the Ohio River ; westerly along the river to a point north of Louisville, Kentucky ; thence northerly again nearly to Indianapolis, Indiana ; thence southwesterly so as to include nearly all of Illinois ; thence northwesterly to a point near St. Louis ; westerly toward Jefferson City, Missouri ; thence along the Osage River and northwesterly through Kansas near Topeka ; through the eastern half of Nebraska, through Dakota west of Bismark, and thence onward into Montana. f " No artificial structure or position will ever subject the stone to the same degree of weathering influence to which it is exposed in its natural position. . . . The rock which has withstood these influences is quite equal to withstand STONES FOR BUILDING AND DECORATION. weather rapidly and yet leave no debris, since its constituents are soluble and may all be carried away by running water, leaving no traces to tell of the havoc going steadily on. Im- pure limestones and all silicious rocks, however, leave more or less debris as mark of their decay. But in regions south of the glaciated area the rock is still covered by the decomposed mass, and hence no clew can thus be obtained. In such cases one can only have recourse to structures that have already been erected from the stone in question and there observe its weathering qualities, or, if these are lacking, observe the stone in those parts of the quarry that have not recently been worked. In opening a new quarry, blocks should always be tested by allowing them to lie and season for at least a year before using. At the end of this time the presence of any readily oxidizable sulphide or carbonate will have made its presence known, and the amount of disinte- gration, or induration, as the case may be, will furnish a slight clew regarding its future behavior. Indeed, this seasoning of stone prior to its introduction into a building should always be insisted upon, whatever its character. A good building stone, whatever its kind, should possess a moderately fine and even texture, with the grains well compacted, should give out a clear ringing sound when struck with a hammer* and show always a clean, fresh fracture. It should also be capable of absorbing only a proportionally small amount of water.f the exposure of a few centuries in an artificial structure." (Hall, Report on Building Stone, p. 24.) * In a report on some experiments on the transverse strength and elastic- ity of building stone, Mr. T. H. Johnson states " the resonance of each piece tested was proportional to the modulus of elasticity as found by the test." (Report State Geologist of Indiana, 1881, p. 38.) f En un mot, les qualites essentielles des pierres tant dures que tendres sont d'avoir le grain fin et homogene, la texture uniforme et compacte ; de resister STONES FOR BUILDING AND DECORATION. 3/9 The porosity of any stone is usually characteristically shown by its manner of drying after a rain ; some will dry quickly, while others that have absorbed a larger quantity of water will remain moist for a long time. In the case of a sandstone it may be said that the grains should be closely compacted, so that the proportion of cement necessary to entirely fill the in- terspaces is comparatively small. Of all cementing materials the argillaceous and calcareous are the least durable, and the purely silicious the most so, the ferruginous cements standing intermediate in the series. Indeed a purely silicious sandstone cemented closely by a silicious cement may be classed as one of the most durable of stones, although unfortunately on ac- count of their hardness and poor colors such can be utilized only at a considerable expense and not always with good effect. Professor Geikie* mentions an instance in which a fine silicious sandstone erected as a tombstone in Greyfriars church-yard about 1646, and defaced by order of the Government in 1662, still showed the marks of the defacing chisel upon its polished surface after a lapse of over two hundred years. (3) COMPARATIVE DURABILITY OF STONES OF VARIOUS KINDS. In this connection the following table upon the " life " of various kinds of building stone in New York City is of inter- est ; by the term life being understood the number of years d 1'humidite a la gelee, et de ne pas elater au feu en cas d'incendie. (Chateau, vol. i. p. 272.) "Any sandstone weighing less than 130 pounds per cubic foot, absorbing more than 5 per cent of its weight of water in twenty-four hours, and effervescing anything but feebly with acids, is liable to prove a second-class stone as regards durability where there is frost or much acid in the air." (Notes on Building Construction, p. 36.) * Geological Sketches, p. 175. 380 STONES FOR BUILDING AND DECORATION. that the stones have been found to last without discoloration or disintegration to the extent of necessitating repairs.* Life in years. Coarse brown-stone , 5 to 15 / ^ Fine laminated brown-stone 20 50 a Compact brown-stone 100 200 j> Blue-stone (sandstone), untried, probably centuries. Nova Scotia sandstone, untried, perhaps 50 200 ^ Ohio sandstone (best silicious variety), perhaps from one to many centuries. I- Coarse fossiliferous limestone 20 40 i{> Fine oolitic (French) limestone 30 40 f Marble, coarse dolomitic 40 // Marble, fine dolomitic 60 80 Marble, fine , 50 100 fa Granite.... 75 200 ^ Gneiss, 50 years to many centuries. The fact that certain quarries have furnished good material in the past is no guarantee of the future output of the entire quarry. This is especially true regarding rocks of sedimentary origin, as the sand and limestones, different beds of which will often vary widely in color, texture, composition, and durability, though lying closely adjacent. In many quarries of calcareous rocks in Ohio, Iowa, and neighboring States, the product is found to vary at different depths all the way from a pure lime- stone to magnesian limestone and dolomite. The cause of this remarkable variation is little understood and can not here be touched upon, but the fact that such occurs is of importance, since in many and perhaps the majority of cases an equal varia- tion exists in point of durability. By English as well as many other authorities a dolomite is, other things being equal, con- sidered more durable than a limestone, and beyond doubt this is the case in localities where the atmosphere is at all acidic, * Report Tenth Census, 1880, vol. x. p. 391. STONES FOR BUILDING AND DECORATION. 381 since dolomite, as already noted, is but little affected by these agencies. Aside from this it would seem yet to be proven that, in the United States, a pure limestone was less durable than one that contained the necessary magnesia to constitute a true dolomite. * Indeed, Professor Hall considers the magne- sian limestones, as a whole, " more friable, more porous, and less firm " (and consequently less durable) than the pure lime- stones, f Stones which are mixtures of limestone (or calcite) and dolomite are liable to weather unevenly, the calcite crystals becoming eaten out, while the dolomite particles are left to project and impart a rough and lusterless surface. Coarsely fossiliferous stones are usually to be avoided for exposed work, as they weather unevenly, owing to the unequal hardness of the fossils and the matrix in which they are em-" bedded. \ Thus the coarse gray Niagara limestone from Lock- port, New York, used in the construction of the Lenox Library building in New York City, began to show signs of decay even * " The nearer a magnesian limestone approaches a dolomite in composition the more durable it is likely to be." " In the formation of dolomite some pecu- liar combination takes place between the molecules of each substance; they possess some inherent power by which the invisible or minutest particles inter- mix and unite with one another so intimately as to be inseparable by mechani- cal means. On examining with a high magnifying power a specimen of gen- uine magnesian limestone ... it will be found not composed of two sorts of crystals, some formed of carbonate of lime and others of carbonate of mag- nesia, but the entire mass of stone is made up of rhomboids, each of which con- tains both earths homogeneously crystallized together. When this is the case we know by practical observation that the stone is extremely durable." (Smith's Lithology, Building Construction, p. 40.) f Report on Building-stone, p. 40. \ The limestone of which was constructed the State capitol building at Nash- ville, Tennessee, has proved so inferior, owing to the weathering out of the numerous fossil orthocera, that the quarries have been discontinued on this account alone. 382 STONES FOR BUILDING AND DECORATION. before the structure was completed. It should be remarked, however, that this extreme rate was due in part to the fact that the stone was laid on edge and not on the natural bed. Mr. Wolff* mentions the case of a monument of shell marble in a Boston cemetery, in which, after seventy years' exposure, the fossil shells stand out in bold relief ; the stone is also covered with fine cracks and is otherwise decomposed. Veined stones are also subject to unequal weathering when exposed ; this being due to the unequal hardness of the vein matter and the mass of the rock. This is true of all stones, but is especially noticeable in the so-called verdantique marbles, where the white veins of calcite or dolomite lose their polish and crumble away more rapidly than the serpentine composing the bulk of the rock. Good examples of this are to be seen in the bases of the two statues in front of the City Hall in Boston. Stones which, like many marbles, contain seams of mica, talc, or other minerals, are objectionable for like reasons. Thus the marble column supporting the statue of Lincoln in front of the City Hall at Washington, though having been in place but some, twenty years, is to-day cracked from top to bottom, owing to the opening of one of these seams of talc. It may be stated further that in the majority of marbles and such other stones as are used chiefly for decorative work, those variously colored lines and veins or structural features which give the stone its chief beauty are in reality flaws and lines of weakness. There is many a beautiful imported marble which when sawn into a thin slab will scarcely bear its own weight, but must be backed by cheaper and stronger material. It may be said here that the essential qualities of a marble, aside from color, which may vary almost indefinitely, are that it shall possess a texture sufficiently compact and hard to take * Report Tenth Census, vol. x. p. 290. STONES FOR BUILDING AND DECORATION. 383 a smooth surface and acquire a high polish. The chief defect in nearly all American marbles, and one that does not as yet seem to be fully realized, is that they are too coarsely crystalline. This not only renders the production of a perfect surface diffi- cult, but the cleavage facets frequently reflect the light from below the surface in such a way as to destroy its uniformity. However good the color may be, a stone of this nature must always rank lower than one that is so fine grained as to appear non-crystalline or amorphous. It is this fact, and this alone, that renders the American marbles now in the market inferior to such as are imported from Belgium, the French Pyrenees, Italy, or northern Africa. Those who are seeking new sources of material will do well to bear this in mind.* Time of quarrying. The season of year during which a stone was quarried may also, in certain cases, be worthy of note. It is well known that many stones can be quarried with safety only during the summer season, but Griiber goes a step further and states f that while the best time for quarrying is during the summer, the freshly quarried material should not be allowed to lie in the sun and dry too quickly, as it is liable thereby to become shaky. This he regards as particularly likely to happen to sandstone. Stone quarried in winter, or during very wet seasons, is liable, according to this authority, to have but slight tenacity when dried, and to remain always particu- larly susceptible to the effects of moisture. Finally, he states, a stone is liable to disintegration if built immediately into a wall without seasoning. Stones for carved work are to be quarried in the spring, since such longest retain their quarry water, and this, if once lost, no subsequent wetting can restore. * Stone, Indianapolis, Indiana, February, 1889. f Die Baumaterialien-Lehre, p. 61. 384 STONES FOR BUILDING AND DECORATION. (4) THE TESTING OF BUILDING STONE. The present methods of testing building stone are at best extremely unsatisfactory and the results obtained very unre- liable. In the majority of the cases, indeed, no attempt is made to ascertain the resistance of the material to the action of fire, frost, or the general effects of weathering. This is due in part (i) to a lack of knowledge of methods by which such tests can be made, (2) to a lack of appreciation of the necessity of such tests, (3) to a desire on the part of quarriers to get the stone immediately upon the market without the delay necessi- tated by a long series of experiments, (4) to the expenses at- tendant upon such experiments, and (5) in altogether too many cases to a desire on the part of interested parties to sell the stone regardless of its qualities. Even the tests that are now applied are in many cases practically valueless, owing to a lack of definiteness in stating results, or our inability with our present knowledge to interpret them properly. Take for in- stance the chemical analysis of a sandstone as ordinarily given. This shows the presence of certain percentages of iron oxides, alumina, lime, and silica, but we have no means of knowing in just what conditions these substances exist ; whether the iron occurs as a hydrous or anhydrous oxide, is confined wholly to the cementing material, or is a constituent of the various min- erals composing the stone itself. The same may be said re- garding at least a part of the silica, alumina, and lime. These difficulties may be in part avoided if the analysis is supple- mented by a microscopic examination, whereby is ascertained the mineralogical nature of the stone, its structure, and the free- dom from decomposition of its constituent parts. And indeed as a rule it may be said that while the analysis of any stone is of interest in a general way, it fails completely to give more STONES FOR BUILDING AND DECORATION. 385 than an approximate idea of its value for constructive pur- poses. Any analysis should always be preceded by a micro- scopic examination, and if the results of such examination should show it to be essential this should be followed by pul- verization and mechanical separation of the mineral constitu- ents, which may in their turn be in part or wholly subjected to analysis. Strength and ratio of absorption. The test of compressive strength is at the present time the principal test to which a stone is put to ascertain its adaptability to any particular kind of structural application. The value of the results are, it seems to the author, greatly overestimated. It is a rule among build- ers to never place a stone where it will be subject to more than one-tenth the pressure it has shown itself by actual ex- periment capable of bearing. Even under these circumstances there is scarcely a stone in the market that would not be found when freshly quarried strong enough for all ordinary purposes of construction. The problem is not what will a selected and carefully prepared sample of the stone bear to-day, but what will it bear after many seasons' exposure to heat and frost. For all ordinary purposes of construction the excess of strength of any stone over 15,000 pounds per square inch is of little value excepting so far as it denotes density, and hence greater resist- ance to atmospheric influences. The size of the cubes tested and the methods used in their preparation are matters that need consideration in making comparisons of results in any series of experiments. General Gillmore found* that within certain limits " the compressive resistance of cubes per square inch of surface under pressure increases in the ratio of the cube roots of the sides of the * Report on compressive strength, etc. , of building stone, Annual Report Chief of Engineers, 1875. 386 STONES FOR BUILDING AND DECORATION. respective cubes, expressed in inches." Thus a series of cubes varying in size from one-fourth inch to 4 inches square were found to give results varying from 4,992 pounds to 11,720 pounds per square inch of surface. It naturally follows that ambitious dealers desiring any stone to show great power of resistance would select the larger sized cubes to be experi- mented upon.* That the method of preparing a cube to be experimented upon is of moment will become apparent when we consider that in the process of dressing a small sample by hammer and chisel it becomes filled to a greater or less extent with small fractures and hence will break under less strain than if carefully sawn out and ground down to a smooth and even surface. Since, as every quarryman knows, no stone, however strong, can endure the enormous strain to which it would be subject if frozen solid when holding any considerable amount of water confined within its pores, it is but natural to conclude, as a matter of course, that other things being equal those stones are most durable which will absorb and retain the least moist- ure.f This rule is not to be accepted, however, without a consid- able grain of allowance, since a coarsely porous stone, though capable of taking up a large amount of moisture will also part with it readily, or if frozen while saturated will permit a con- siderable proportion of the expansive force of the solidifying * See further, Gillmore's remarks under " Compressive Resistance of Various- sized Cubes," on pp. 20-29 of his Notes on the Compressive Resistance of Free- stone, Brick Piers, Hydraulic Cements, Mortars and Concretes. (Wiley & Sons, 1888). The law as above given does not appear to hold good for blocks of large size, such as are used in actual building. f " Other things being equal, it may probably be said that the value of a stone for building purposes is inversely as its porosity or absorbing power." (Hunt, "Chemical and Geological Essays," p. 164.) STONES FOR BUILDING AND DECORATION. 387 water to be expended otherwise than in pushing apart the grains composing it. Otherwise expressed, the water will freeze out of a coarsely porous stone, while in one that is compact it may create sad havoc. This is well illustrated by the common occurrence of water freezing in straight cylindrical or widely- expanding vessels, and in narrow-necked pitchers and bottles. In the first instance the open space above is sufficient to allow all the expansion to take place vertically. The narrow-necked vessel, on the other hand, is almost invariably broken. To ascertain the porosity or ratio of absorption of any stone is nevertheless an important test : To ascertain the ratio of absorption and resistance to freezing while saturated is a most important, and for a single test the most conclusive of any one test yet suggested. Nevertheless it is one which is at present almost wholly ignored. I will refer to methods which have been employed to some extent in times past. Obviously the best method of ascertaining the power of a stone to withstand the effects of frost is to actually expose pre- pared blocks to such a temperature, when saturated with water, as to freeze them solid and then note the amount of disinte- gration, or loss in strength. Unfortunately this can not at all times of the year and in all places be done, and artificial meth- ods must be resorted to. Brard's process, as modified by M. Hericart and Thury, consisted in boiling the cube to be exper- imented upon for half an hour in a saturated solution of sul- phate of soda (Glauber salt) and then allowing it to dry, when the salt taken into the pores crystallized and expanded in a manner supposedly somewhat similar to that of water when freezing. * This process is not now in general use, as experiment has shown that the salt exercised a chemical as well as mechanical * Chateau, Technologic Du Bailment, vol. i. p. 262. 388 STONES FOR BUILDING AND DECORATION. action, and produces results somewhat at variance with that of freezing water. The most important series of experiments ever performed with the process in this country were those of Mr. C. G. Page, made with reference to the selection of material for the Smithsonian Institution building at Washington. The results are given in the following table : * MATERIALS. Marble, close-grained, Maryland Marble, coarse " alum stone," Baltimore County, Maryland. Marble, blue, Maryland Sandstone, coarse, Portland, Connecticut Sandstone, fine, Portland, Connecticut Sandstone, red, Seneca Creek, Maryland Sandstone, dove-colored, Seneca Creek, Maryland Sandstone, Little Falls, New Jersey Sandstone, Little Falls, New Jersey Sandstone, coarse, Nova Scotia , Sandstone, dark, coarse, Seneca Aqueduct, Peters's quarry Sandstone, Acquia Creek, Virginia Sandstone, 4 miles above Peters's quarry, Maryland Sandstone, Beaver Dam quarry, Maryland Granite, Port Deposit, Maryland Marble, close-grained, Montgomery County, Pennsylvania. Limestone, blue, Montgomery Coun ty, Pennsylvania Granite, Great Falls of the Potomac River, Maryland Soft brick Hard brick Marble, coarse dolomite, Mount Pleasant, New York Specific gravity. 2.834 2,857 2.613 2.583 2.672 2.486 2.482 2.518 2.230 2.609 2.727 2.699 2. 211 2.294 2.860 Loss in grains. 0.19 0.50 0.34 14.36 24-93 0.70 1.78 1.58 0.62 2.16 5.60 18.60 1.58 1.72 5.05 0-35 0.28 0.35 16.46 1.07 0.91 The specimens operated upon, it should be stated, were cut in the form of inch cubes. Each was immersed for half an hour in the boiling solution of sulphate of soda, and then hung up to dry, this performance being repeated daily throughout the four weeks which the experiment lasted. Although as above noted this process is practically aban- doned, the series of tests given was productive of certain From Hints on Public Architecture, by Robert Dale Owen, p. 119. STONES FOR BUILDING AND DECORATION. 389 results which are well worth a moment's consideration. Thus the red sandstone from Seneca Creek, Maryland, with a spe- cific gravity of 2.672, or a weight per cubic foot of 167 pounds, lost by disintegration but 0.70 grains. This was the stone ulti- mately selected for the Smithsonian Institution building, and the structure as a whole is to-day probably in as good a state of preservation as any of its age in the United States. The second stone, from Acquia Creek, Virginia, with a specific gravity of 2.23, or a weight per cubic foot, of but 139.37 pounds, and which lost 18.6 grains is the one used in the con- struction of the White House, and the old portions of the the Capitol, Interior Department and Treasury buildings. This stone has proven so poor and disintegrates so badly that the buildings are kept in a condition anywise presentable only by repeated applications of paint and putty. The results obtained with hard and soft brick are also very striking : the one weigh- ing at the rate of 138 pounds per cubic foot losing 16.46 grains, while the harder brick, weighing at the rate of 143 pounds, lost but 1.07 grains. If anything can be learned from the series^ it is, that with substances having the same compo- sition, those which are the most dense which are the heaviest, bulk for bulk will prove the more durable. The results obtained on coarse and fine varieties of Portland sandstone, suggest at least, that water would freeze out of the coarser stone, and therefore create less havoc than in that of finer grain, a probability to which I have already referred. That, however, the ratio, of absorption cannot in all cases be con- sidered the controlling item is shown in the case of the coarse ''alum marble" from Baltimore County. This stone is act- ually so poor as to be no longer in general use, yet in the test it lost but 0.50 grains, less than did the durable Seneca stone. It is probable that the difference in durability here lies in the solubility of the marble in the water of rainfalls, together with 390 STONES FOR BUILDING AND DECORATION. a mechanical disintegration produced by temperature changes on a rock so coarsely crystalline. These agencies have been referred to elsewhere. The specific gravity or density of stone having been con- sidered by many as sufficiently indicative of their strength to be authoritative, the series of tests given below were made by Dr. Bohme. The results obtained seem to show that while with limestones this might be true, with sandstones such tests could not be relied upon. A moment's reflection will be sufficient to show us the cause of this, since the strength of any stone, which is but an aggregate of minerals, is necessarily dependent not upon the hardness, density, or toughness of the individual minerals themselves, but upon the tenacity with which the adhere to one another. (See ante, p, 38.) (a) Limestone with a specific gravity 0/~2.68. Five wet samples. Five dry samples. Lowest strength 7,154.16 7,267.95 Highest strength 9,984.54 10,581.91 (b) Limestone with a specific gravity of 2."]O. Eleven wet Eleven dry samples. samples. Lowest strength 8,050.22 8,050.22 Highest strength ,... 10,738.36 12.515.80 (c) Limestone with a specific gravity 0f2.ji. Six wet Six dry samples. samples. Lowest strength , 7,196.83 7,879.54 Highest strength 12,316.72 13,668.60 STONES FOR BUILDING AND DECORATION. 39 1 (a) Limestone with a specific gravity 0/2.72. Five wet samples. Five dry samples. Lowest strength 9,073.27 9,600.50 Highest strength t i5,O33-7 1 14,934- 1 5 (e) Sandstone with a specific gravity of 2.54. Wet sam- Dry sam- ples, pies. No. I 12,487.40 13,668.60 No. 2 15,488.80 14,607.02 (f) Sandstone with a specific gravity 0/2.56. Wet sam- Dry sam- ples, pies. No. I 10,169.44 9,700.10 No. 2 18,518.24 18,902.37 Sandstone with a specific gravity of 2.59. Wet sam- Dry sam- ples, pies, No. i.... 8,932.04 9,700.10 No. 2 11,051.27 11,349.56 No. 3 17,224.45 16,754.40 See American Architect, November 4, 1882. By the term modulus of elasticity is understood the amount of force in pounds requisite to stretch a bar of any material I inch square to twice its original length, provided the rate of stretch could continue uniform throughout the trial without the breaking of the material. The modulus of 'rupture is the force requisite to break a similar bar I inch square resting 392 STONES FOR BUILDING AND DECORATION. upon supports I inch apart, the load being applied in the middle. So far as the writer has been able to learn, but few tests of this nature have been made upon stone. The following are from the report of Mr. T. H. Johnson.* It will be noticed that there is a strong discrepancy in favor of sawn over tool-dressed stone. Kind of stone. Modulus of rupture. Modulus of elasticity. Crushing strength. Oolite limestones, Indiana, tool dressed*. . Oolite limestones Indiana sawnf .... 1,477 2 ^^8 2,679,475 4 889 480 7,357 12 67^ Granite, Hallovvell, Maine, tool dressed \ . . 1 >754i 2,511,800 470 an8 2^4. 2,82^ 6 300,000 l6 SI2 * Average of twelve determinations, f Average of four determinations, j Average of two determinations. Average of five determinations. Average of four determinations. As to the method of testing : Assume first that the stone is designed for use in the ex- terior walls of a building, subjected to all the vicissitudes of our northern climate, and to only such conditions of pressure and strain as may exist in any large buildings. All things considered, it seems best that the tests be made on two-inch cubes. These should be prepared by sawing and grinding, never by hammer and chisel. After 'drying at a temperature not exceeding that of boiling water, the ratio of absorption should be determined by complete immersion for a period of not less than twenty-four hours. The cubes should then be repeatedly frozen and thawed while in this saturated condition, and the amount of disintegration ascertained by careful weighings. If the stone is a fragmental one (sand- stone), and it is found to suffer appreciable disintegration * Report State Geologist of Indiana, 1881, p. 45. STONES FOR BUILDING AND DECORATION. 393 by freezing, it may be well to ascertain the loss in strength also. This can be done by crushing these same cubes after the freezing tests, and also freshly prepared cubes of the same material not otherwise tested. The freezing can be brought about by means of such apparatus as is used in the manufac- ture of artificial ice or as Chauvenet has done, by placing the saturated cubes in the centre of a large box which is then placed in a mixture of pounded ice and salt.* The question of durability of color and resistance to atmos- pheric action, can, in the laboratory, be settled only by chemical and microscopic tests. The condition of the iron, whether in the form of sulphide or protoxide carbonates is the main question to be considered. A little may perhaps be learned by submitting the stone to the action of artificial atmos- pheres, samples being suspended for a period of several weeks under bell-glasses charged with acid fumes. The resistance to the action of carbonic acid, can perhaps be best determined as Professor Winchell has donef by placing the samples in a basin of water through which carbonic acid gas is kept constantly bubbling. This test is scarcely necessary, except upon cal- careous rocks, or fragmental rocks with ferruginous or calcareous cements. The determination of the modulus of elasticity as made by processes now in vogue, is apparently sufficiently accurate. When as sometimes happens, it is desirous to ascertain the relative powers of resistance to wear, as in pavements, or from wind-blown sand, this can readily be done by means of a carefully regulated sand-blast, such as is used in the Tilghman process of stone-carving. This property might almost equally well be learned by observing the manner * Second Biennial Report Board of Capitol Managers to the General Assembly of Colorado, 1886. f Geology of Minnesota. Final Report, vol. i. 394 STONES FOR BUILDING AND DECORATION. in which the stone works under the chisel. Pressure tests when necessary at all, may be made on the two inch cubes prepared as above, and crushed between steel plates, as in any of the leading testing machines. After all that has been said and written, there are no tests or series of tests equal to an examination of the stone in its natural outcrops, or in structures of long-standing. How- ever careful, elaborate and apparently exhaustive may be a series of tests in the laboratory, they should always be supple- mented, when possible by such field examinations. Indeed if the writer were called upon to-day to decide a question of this kind, upon any but the purely calcareous rocks, and was re- stricted to either field examinations or laboratory tests, he unhesitatingly declares that, with good natural outcrops, or quarry openings of long standing, he would choose the field examination, no matter how elaborate the other tests might be. A very essential item in this connection, is that all the tests be made under the direct supervision of one thoroughly acquainted with the mineral and chemical character of the rocks, their structure, origin, mode of occurrence, and character- istic manner of weathering. A purely theoretical knowledge is worse than valueless, and only one who has devoted much time to the work, both in the laboratory and in the field, can hope to deal with the matter successfully. One great difficulty with all such work, is that we are prone to expect too much, to obtain immediately results which, in the ordinary course of events, can be brought about only by months and perhaps years of careful observation, experiment and study. STONES FOR BUILDING AND DECORATION. 395 METHODS OF PROTECTION AND PRESERVATION, (l) PRECAUTIONARY METHODS. Position in wall. All authorities agree that stratified stone should be placed in the walls with the bedding horizontal, or at right angles to the direction of greatest pressure. Not only are they as a rule strongest in this position, but as they will absorb less water they are correspondingly less liable to suffer from the effects of frost. This fact has already been sufficiently dwelt upon. The denser and harder stones should as a rule be used in the lower courses; the lighter ones in the superstructure. The non-absorbent stones should be used in the ground and in plinths, sills, strings, courses, and weather beds of cornices, etc.; the softer and more absorbent ones may be used for plain walling.* The necessity of laying non-absorbent stones in the ground becomes apparent when we consider that in this position they are in contact with more or less moisture, which, when ab- sorbed, is liable to cause discoloration, and damp, unhealthy walls. If from necessity porous stone are used, a coating of water-proof material, as asphalt, should be interposed between those courses that are in contact with the ground and those of the superstructure/)- In laying the lower courses of Lee dolomite in the walls of * Cyclopedia of Arts and Sciences, vol. vn. p. 839. f T. Egleston, American Architect, Sept. 5, 1885. This authority states further, that in the exterior walls of Trinity Church, New York, the stone for the first 60 or 70 feet in height is more decomposed than above this point. This is in part accounted for on the supposition that the atmosphere near the ground contains a larger proportion of acid gases than at higher altitudes. STONES FOR BUILDING AND DECORATION. the Capitol at Washington, the stone was observed to show a brownish discoloration, due to the absorption of .unclean water from the mortar. This difficulty was finally remedied by coating the lower surfaces of the stones where they came in contact with the mortar with a thin layer of asphalt which prevented such absorption.* No one who has given the subject any attention can have failed to remark how, in town and city houses constructed of the Connecticut or New Jersey brown sandstones, the blocks in the lower courses those in close proximity to the sidewalks almost invariably scale after an exposure of but a few years, while those in the courses above remain intact for a much longer period. This is due to the fact that these lower courses are kept almost constantly wet, receiving not only the water that falls as rain upon the walls above, but also that which splashes from the walk or is absorbed from the ground. As noted by Chateau,f it is not those portions of a wall that receive the water from rains direct that are most and earliest liable to decomposition, but the under and partially protected portions, as those under the cornices, the entablatures and the tablettes of balustrades upon which the water drips or runs more slowly. It is for this reason that architects advocate the under-throating of window sills and other projections in order that the water may be thrown off from the building and not allowed to run down over the face of the stone beneath. The disastrous effects from neglect of this proceeding have been dwelt upon by Julien in reference to buildings in New York City. The author has in mind the costly residence of a former Cabinet minister in Washington in which the middle portion of the brownstone entablatures are almost continually wet * Silliman's Journal, xxn. 1856, p. 36. f Op. cit., p. ii. STONES FOR BUILDING AND DECORATION. 397 throughout the winter months by the soaking through of water from above. The stone steps in the same house are constantly wet and show a whitish efflorescence. Both these defects are liable to appear in so porous a material, but might in large part have been averted by exercising proper care in building. It may not be out of place here to comment on the folly of placing iron railing on steps, platforms, etc., of finely finished granite, since in spite of paint and other means of protection the iron invariably rusts, staining and badly defacing the entire surface beyond possibility of repair. The method of dressing a stone has an important bearing upon its durability. As a rule it may be set down that the less jar from heavy pounding the surface is subjected to the better ; this for the reason that the constant impact of the blows tend to destroy the adhesive or cohesive power of the grains, and thus renders the stone more susceptible to atmospheric in- fluences. It is stated by Mr. Batchen that some of the dolo- mites used in Chicago, although apparently perfectly sound when quarried, shortly showed a tendency to scale on expo- sure. On examination it appears that, in dressing, these surfaces were both ax- and bush-hammered, the implements used weigh- ing from 8 to 12 pounds, and capable of striking blows of not less than 150 or 200 pouads. The effect of these heavy blows was to "stun"* the surfaces for the depth of from one-six- teenth to one-eighth, or even one-fourth, of an inch, and on ex- posure scaling resulted, leaving them ragged and unsightly. Sawn surfaces of the same stone, on the contrary, do not usually show the slightest tendency to scale. Results such as these are what one is naturally led to ex- pect, but further experiments are necessary before it will answer to speak too positively regarding the merits or demerits * I.e., to break the grains and produce minute fissures. 39$ STONES FOR BUILDING AND DECORATION. of various kinds of finish. With compact crystalline rocks like the granites and diabases it would seem probable that rock- faced work, untouched by chisel or hammer, would prove most durable, since the crystalline facets thus exposed are best fitted to shed moisture and the natural adhesiqji of the grains has not been disturbed.* With the softer and more absorbent stones on the other hand, the rock surface from its irregularity and roughness is more susceptible to the attacks of moisture and atmospheric acids, and hence would probably be found less durable, al- though from its roughness at the start any disintegration is less noticeable than on finely-finished work. With such stones a smoothly-sawn or polished surface seems best adapted to our variable climate, f * The single experiment of Pfaff , in which a polished granite was found to weather more rapidly than one unpolished, seems too anomalous to be accepted until further proof is offered. A polished surface must naturally shed water more readily than a sawn or tool-dressed one, and hence it would seem that it should be more durable. It is of course possible that, owing to the manner in which the smooth surface necessary for polishing was produced, the surface minerals were badly shattered, and hence succumbed the more readily on expo- sure. f " Professor Hall, writing on the methods of dressing certain argillaceous limestones (Report on Building Stones, p. 36, 37),says : " In the dressing of lime- stone the tool crushes the stone to a certain depth, and leaves the surface with an interrupted layer of a lighter color, in which the cohesion of the particles has been partially or entirely destroyed ; and in this condition the argillaceous seams are so covered and obscured as to be scarcely or at all visible, but the weathering of one or two years usually shows their presence. " The usual process of dressing limestone rather exaggerates the cause of dilapidation from the shaly seams in the material. The clay being softer than the adjacent stone the blow of the hammer or other tool breaks the lime- stone at the margin of the seam and drives forward in the space little wedge- shaped bits of the harder stone. A careful examination of dressed surfaces will often show the limestone along the seam to be fractured with numerous thin wedge-shaped slivers of the stone which have been broken off and are more or less driven forward into the softer parts. In looking at similar surfaces which STOA'ES FOR BUILDING AND DECORATION. 399 (2) PROTECTION BY MEANS OF SOLUTIONS. Many methods have been devised for checking or altogether preventing the unfavorable action of the weather upon build- ing stone of various kinds, but none of them can be considered as really satisfactory. The problem, as may be readily under- stood, consists in finding some fluidal substance into which the stone may be dipped or which may be applied with a brush to its outer surface in such a manner as to fill its pores and thus prevent all access of moisture. Whatever the substance, it must be of such a nature as in no way to discolor or disfigure the stone. Paint. This is one of the substances most generally used, and which has been employed on the porous sandstone of the Capitol, White House, Patent Office, and other public build- ings in Washington. It is found necessary to renew the coat- ing every two or three years, and even then the results are un- satisfactory. OIL This always discolors a light-colored stone, while it renders a dark-colored one still darker. The oil is applied as follows : The surface of the stone is washed clean, and after drying is painted with one or more coats of boiled linseed oil, and finally with a weak solution of ammonia in warm water. This renders the tint more uniform. This method has been have been a long time exposed to the weather, it will be seen that the stone adjacent to the seam presents an interrupted fractured margin, the small frag- ments having dropped out in the process of weathering. Limestones of this character are much better adapted to rough dressing, when the blows are directed away from the surface instead of against it, and when the entire sur- face shall be left of the natural fresh fracture. By this process the clay seams have not been crushed, nor the limestone margining them broken, and the stone withstands the weather much longer than otherwise. The attempt at fine hammer-dressing is injurious to any stone, for the cohesion of the particles is necessarily destroyed, and a portion of the surface left in a condition to be much more readily acted upon by the weather." 400 STONES FOR BUILDING AND DECORATION. tried on several houses in New York City, and the water-proof coating thus produced found to last some four or five years, when it must be renewed. Paraffine. This, dissolved in coal-tar naphtha, is spoken of,* but is not recommended. A better method consists in brushing over the surface of the building with melted paraffine and then heating it gently until it has been nearly all absorbed into the pores of the stone. This produces little or no dis- coloration, but it is thought doubtful by some if the heating of the stone is not more injurious than the paraffine is beneficial. The preparation used in coating the Egyptian obelisk in Central Park, New York, is said by Mr. Caffal f to have con- sisted of paraffine containing creosote dissolved in turpentine, the creosote being considered efficacious in preventing organic growth upon the stone. The melting point of the compound is about 140 Fahrenheit. In applying, the surface to be coated is first heated by means of especially designed lamps and charcoal stoves, and the melted compound applied with a brush. On cooling it is absorbed to a depth dependent upon the degree of penetration of the heat. In the case of the obelisk, Mr. Caffal states that, in his belief, it was absorbed to the depth of half an inch. Some 6/f pounds of the material was used in going over the 220 square yards of surface. An equal surface of brown sandstone is stated to require ordinarily about 40 or 50 pounds. The cost of treating an ordinary 25- foot brownstone front, with a porch, is given by this authority at from $200 to $300. This process, like the last, has been objected to by some on the ground that the heating was liable to injure the stone. Just how much injury is likely to result from a temperature lower than that of boiling water, it is per- * Notes on Building Construction. f Transactions New York Academy of Science, November, 1885, p. 66. STONES FOR BUILDING AND DECORATION. 40 1 haps yet too early to say. It seems scarcely possible that a good quality of sandstone laid on its bed could be at all unfavorably affected ; neither, it is safe to say, would brick. Soft soap and alum solution; Sylvester s process. This con- sists of three fourths of a pound of soft soap to one gallon of boiling water and one half a pound of alum in 4 gallons of water. It is said to answer well in exposed situations in England, but to require frequent renewal. It is stated,* how- ever, that this solution was applied in 1863 to the stone-walls forming the back bays of the gate-houses of the Croton reser- voir in New York for the purpose of rendering them imper- vious to water, and that up to 1870 the date of the report it had served the purpose intended. Ransome' s process. This consists in saturating the stone as far as practicable with a solution of silicate of soda or potash (water glass) and afterwards applying a solution of chloride of calcium. This last coming in contact with the silicate pro- duces by double decomposition an insoluble silicate of lime, cementing the grains of which the stone is composed firmly together. f " The solution of silicate is first applied in a dilute form so as to be absorbed readily into the pores of the stone. Several coats are applied with an ordinary whitewash brush and when thoroughly dry the surface is washed with rain water, again allowed to dry, and the calcium solution applied in the same manner. The precautions to be used are: (i) the stone must be clean and dry before applying the solution ; (2) the silicate must be applied until the stone is fully saturated, but no excess must be allowed to remain on the surface ; the calcium must * Transactions American Society Civil Engineers, vol. i. p. 203. f Dobson, Masonry and Stone-Cutting, p. 141. See also American Archi tect and Builder, 1877, n. p. 21, 38, and Notes on Building Construction, p. 79- 4O2 STONES FOR BUILDING AND DECORATION. not be applied until after the silicate is dry ; a clear day or so should intervene if possible ; (4) care must be t&ken that either solution is not splashed upon the windows or upon painted work, as it cannot be removed therefrom ; (5) upon no account should the same brush be used for both solutions. Under ordinary circumstances about 4 gallons of each solution will be required for every 100 yards of surface." Szerelmey's stone liquid is stated to be a combination of Kuhlman's process with a temporary wash of some bituminous substance. The wall being made perfectly dry and clean, the liquid is applied in two or three coats with a painter's brush, until a slight glaze appears on the surface. This composition was used with some success in arresting for a time the decay of the stone in the House of Parliament.* Kuhlmaris process consists in simply coating the surface of the stone with a silicate of soda or potash solution. It is open to the objection that the potash absorbs carbonic acid from the air and produces a disagreeable efflorescence, which, how- ever, disappears in time. M. Lewiris process consists in coating the surface of the stone with solutions of an alkaline silicate (silicate of potash) and alumina, the latter in the form of sulphate. It is stated that this wash will give so close a surface to sandstone that it can be polished. (?) Either of the solutions can be colored if desired. f Various other solutions, including those of beeswax, rosin, and coal-tar, have been tried, both in this country and in Europe; but in nearly every case with indifferent success. The Droblem of devising a perfectly satisfactory preservative yet remains to be solved. * Notes on Building Construction, p f Journal Franklin Institute, 3rd, L? :tion, p. 79. 3rd, LXIX, 1875, p. 338. PART IV, APPENDIX I. THE QUA LIT IRS OF BUILDING STONE AS SHOWN BY THEIR CRUSHING STRENGTH, WEIGHT, RATIO OF ABSORPTION, AND CHEMICAL COMPOSITION. 403 404 APPENDIX /. a 11 ^_ ^H S cc O p M 8 02 2 I Is Is OQ C_H O2 S W r^ 2-S | o-s |i| i|i| U3 lO CO CO t- i- I- GO i JiO i I- t- CJ K> OJ 'f O CO O 1ft C<)C-C- O C ^SS 2 SMOt-C- CO ] .SSSSSS8SSSSSSSSSSS ^oiciojoiojcJdoJcioJwwT^oJoJTioJ xxxxxxxxxxxxxxxxxx o o o c o c . o a g o-a ^ 1 1 S acemsea, o Greenwich, Conn Ne^v London, Co SS tf^-8 .i g, s o P*J ^ p -/. 'E c O e- S O . ! I'll APPENDIX /. 405 e-1 M O3 1 eo ej w c c IT3 1-1 OO iH or^-^c ooo^ to oot** 'oooooo t-aococooot~o iH 10 o oo M 10 10 ir: 10 icio :-g. 1 OP '****' a^ ^ a X XX II -2 L 5 1 a h ! fll > S 95 "X3 c 5 : &1 5 S 1 1 \ 1 II M C5 O CUW . a S I ^ S a >; * a "fc 3 r^l > 6 1 S S | I S5 5 5 APPENDIX /. 407 408 APPENDIX /. "Si, O H >, .53 ^ S 1 I !lii s ^^ a - s | iill H 3 il ' 1 |l * . B ! 1* 1 i "o 8 1 ft E urst without verago of thi out cracking 4- 1 1 1 'C V c ( 1 t urst without > : c ^ ^ PM -t pq eoeo eo w r-> S S oc oo 35 a> ac ao 02 So S 1 S S ! P II X X XX^X X XX io5S?8!3S to -.0 irf o >' ia iri i in iri irf id . a .9 3 a a 1 Canton. Mo Glen's Falls, do a I s aillsl4 APPENDIX /. 409 ' 1 n | 1 S i ?, : ; 4 : 1 s S . Jo 1 S M ' a 11 lNi|i| ^ S Jj . ffi S r-i . H R- : o'S. ^ J.5 3* S X Average of three trials Burst without cracking 1 Average of four trials ; out cracking. Average of three trials { Probable reduction in a i uneven bearing. C Failed immediately afl \ of rapid yielding. No signs of failure till ttlnr.fc snlit nn Qlnnff ofT C Failed immediately aft { ot weakness. Crushed with slight ex do Crushed with qniet exp Crushed with slight ex cracks. A. remarkably solid, ste Burst without crackin?. Average ot two trials; I cracking. Burst without cracking ; ; to I I m njai ; ; : fi H i n fs in r- ?2 CO $ to ., feS'SS firs ^ isl s-;- ^ *** CO CO CO e4c- oc oo "M c^ X5 ' C^ c o r-T 0" Tl 00 t* o re i^ o" c^ ?i 1 ' I . 1 1 , , , ' ! i ' ' I ! XX XX XX XX XX XX XX XX XX .: ;.s : ' O ! ; I h ' ! 8-3 S i Ijji !!|! S : ! i ! ! If I J 3 ixS I 410 APPENDIX I. o fc ( I w & P5 g . 1* il .-i 2 t . 5 .. . o - * sg- MO OO WM W WMfQCQ CQO P3 PQ K 23 l ^^lOJ OS O S S ^ fe OOOr-.QO o o c c II s oo"> ocTos" cToT co'i-T i-'cT ^-"eo" i>" em-r4<&ef*?G>ai9foieG?meoG> feS 8S S8 o 38 88 5S S oi i ei XX XX XX XX 88 SS SS SS S 88 "+ 3 0, Q := I f II 3 i I i^s s s I I si* tl *2 . .a CTJ o -o S S| | ^.S^|| II i I::":" o ra o w M *rss I ta a' a 2 as ^ - M | s^sP 5a t s a s cc oo n ?t ro oo '-"5 a ci i a i cfo" icfio" os't-' assg^gfsj 5o<^SSto?iS&e4( ^,ss Sww S8S8SSSSSSSSSS SS 8S SS^^SS? o i-i TJ oj 5^ ci c j oi c> i i-i r-< c* -- ;* ci ci TJ bO-d XX XX XX I it U3 .3 = " a -,-* o & Sl &&& OQ 414 APPENDIX 7. .2 o Q w $ j 5 3 S^S :ooog 1'" l"! e< 1 odd o d d i d |U o e So o U * | 1 (N t- 1 . s g J3,,S8S ^ o ^0 d i-< o' o' 0* fr es S @ BQ PH S 5 co II e OMt-OWCO cs cs m ci n t> CO o n eo H c o c :! ^3 5* o CO .g 45 n f co r > jjl 1 S frj Ci CO -H' j j OD ! ! 05 ii d r S gg i 1 i ! ! 3 $ .Is - >M i 3 j 1 1 -J ! I 3 D Limestones and dolomites other than ^l/imitr, T.OTnrTit Til i j r 1 3 mestone (oolitic), Belfonl, Ind mestone (oolitic). Spencer, lud ruestone, Bloomington, Ind inestone, North Vernon, Ind mestone, Harrison County, Ind. (Stockla mestone, Flat Hock Creek, near Saint P mestone, Green bury, Ind licious limestone, Putnamville, Ind agneaian limestone, Anaraosa, Iowa a^nesian limestone, Le Claire, Iowa ... 1 C <5 c I 3 5 jjj^jj^aa a a APPENDIX /. 415 C?S . s !g S o M 10 cj^cS*^' ^ rt i S ei s i5 e ^1 53- 1 ol r 2 2 i ri s rj 5 5 19 ss ^3 S 2 ; s s 'o i" l o> o t< co oo .5 * S? S S - V *l s g S co : S S? ) 3 " \ \ i ; J^ CO -V o : : : ; ; 25 ~\ IQ 1 t ? ; , 2 S I g "~ V : -( i i 'rH ~ 3 1 : s S 3 co t- m CO : i : 8 i ; o * o o o J J J 11 2 s< W rH 2 S -S o vo c 3 I 8 ih! s s S3 S S s? irf r^ ; S Sg & i S 3 t '. a 09 *! ? CO 00 o co . co o> o < M 9 95 i i i > e d S S S oo s 1 1 "3 u . DO aD oo a X 00 i x < iiand, Iowa eCity.lowa Solenhofen. Bavaria . . TJ ll 4 * 1 s )apolis,Minn. ( Weeks | C> ^ co* oicq ci o> S g S5 S 2 32 g 1 o o o 00 r4 3 Jg & 8 S 3 i fS3 * s * 8 *eo ^ S 2 s 1 5 1 iO OS ^ r^ s [* fc j r s S 8 5 -H eod M 0> U5 OO 00 r-l t S S S S ed uiao co o T- co-* o >o * . i g i ! : : >* \ : w : ea i d ^ 4 1 5 j i , a . -I a a ^ B 1 || I f go ^ ^2 g 3 ^ s s i H* ^ ^ I" ^ I" I* c |" ^ g a" g" s s 1 o S S S S 42O APPENDIX I. . 2SS & 53 : : o' so c* i-< i-i o containing not leaa tuau Third . ..do Tanti Scritti 4 to 4.26 20 cubic feat. First Second White veined do Vara Gioja 10.50 7 First Bardielio Para a. so Second ... do Gioia 6.50 First Bardielio veined Serravezza . a 75 Second . . do .. do 7.25 First Portor black and gold Spezia 10.50 Do... Red mixed Levanto ....... 10.50 Do.. Pariiiazo . ........... Misedia 12 do Pescma. ...... 12 Prices of all of these de- do Bocca del Frobbi 12 > pend upon the sizea of Yellow 18 to 20 the pieces and the Portor Mnntft d' A rnia 11 beauty of the vetoing. Black Colonnata 10.50 Breccia ............ Gragnana . . Exceptional. Yellow do do do do Genoa do .. Breccia Serravezza ....do Yellow Verona . . .. do . Ked Castel Poggio 7 *A lira equals 19.3 cents American money. NOTE. For this list of quarries and prices we are indebted to Hon. William P. Rioo, United State consul at Leghorn, Italy. APPENDIX III. LIST OF SOME OF THE MOEE IMPORTANT STONE STRUCTURES OF THE UNITED STATES. Locality. Akron, Ohio .. Albany, N. Y. Augusta, Me Atlant!.. ^a... Baltimore, Lid Bangor, Me . . Boston, Maes Structure. Memorial Chapel State Capitol City Hall United States court and post-of- fice building. State Capitol Asylum for the Insane United States Arsenal United States post-office and court-house. Eutaw Place Baptist Church Presbyterian Presbyterian Material. Sandstone, Marietta, Ohio Granite, Hallo well, Me. (in great part). Granite, Millford, Mass Granite, Maine , Granite, Hallowell, Me do do Granite, Yt White marble (dolomite), Texas and Cockeysville, Md. do .do. Brown Memorial Church. Franklin Street (Jhurch. City Hall Peabody Institute First Presbyterian Church i Sandstone, New Brunswick, N. J . City Prison Gneiss, Jones's Falls, Md. .do. do. Catholic Cathedral . Post-office and custom-house King's Chapel United States custom-house United States court-house Masonic Temple St. Paul's Church Merchants 'Exchange Mount Vernon Church Unitarian Church, Jamaica Plains. Bowdoin Square Baptist Church.. Bunker Hill Monument United States post-office Boston Water- works St. Vincent de Paul Church Herald Building Transcript Building Advertiser Building Gneiss, Ellicott City, Md. Granite, Frankfort, Me... Granite (bowlders) Granite, Quincy, Mass Massachusetts General Hospital..; do Granite, Cape Ann, Mass do do Granite, Concord, N. H .. do do Massachusetts General Hospital I do (addition). Granite, Westford, Mass Eqiitable Insurance Company's building. Odd Fellows' Memorial Hall (in part). Parker House, on School street St. Cloud Hotel Hotel Dartmouth Hotel Vendome (old part) New York Mutual Life Insurance Company's building. Hotel Vendome (new part) Hotel Pelham... Second Unitarian Church. Arlington Street Church.. Young Men's Christian Union, Boylston street. Young Men's Christian Union. . . Granite, Hallowell, Me ...do... Marble, Rutland, Vt do do Marble, Italy Marble (dolomite), Tuckahoe, N. Y. .do. Bed sandstone, Portland, Conn., and New Jersey. Eed sandstone, Newark, N. J Bed sandstone, Belleville and Lit- tle Falls, N.J Red sandstone, Bay View, New Brunswick. Sandstone, Amherst, Ohio 424 Date of erec- tion. iaaa-'82 1884 1829-'32 1837-'40 1823 1880 180S 1855 1749-'54 1837.'43 1830-'31 1828-'29 1829 1842 1825-'42 iaia-'2i 1849 1854 APPENDIX III, 425 LIST OF SOME OF THE MORE IMPORTANT STONE STRUCTURES OF THE UNITED STATES Continued. Locality. Structure. Material. Date of erec- tion. Boston, Mass . Brooklyn, N.Y Cambridge, Mass . . . Chicago, 111 Columbia, S. C Denver, Colo . Denver, Colo . Hoboken, N. J Hout?hton, Mich. . Indianapolis, Ind. Jersey City, N. J. Lansing. Mich... Louisville, Ky... Maiden, Mass Middletown, Conn .. Minneapolis. Minn . Mobile, Ala Nashville, Tenn Newark, N. J New Orleans, La ... New York City Harvard College Building, Arch street. First Church, Marlborough and Berkeley streets. Brattle Square Church Sandstone, Amherst, Ohio Conglomerate, Roxbnry, Mass^. Central Congregational Church.. Emanuel Chuach, Newbury street .do. .6.0. New Old South Church Second Universalist Church Tremont Street Methodist Epis- copal Church. Cathedral of the Holy Cross St. James (Episcopal) Church... St. Peter's Church (Dorchester) . Trinity Church Academy of Design, Montague street. Soldiers' Monument Court-house ... .do. .do. .do. .do. do. .do. do. post-office do Custom-house and building. Chamber of Commerce . Palmer House Grand Pacific Hotel St. Paul Universalist Church Union League Clubhouse Granite, Dedham, Mass ! . Brown sandstone, Portland, Conn. J Granite, Mason, N. H Dolomite, Lemon t, 111 S Granite, Fox Island, Me ^Oolitic limestone, Bedford, Ind Sandstone, Freestone, Ohio Granite, Fox Island and Hallo- well, Me. Sandstone, Amherst, Ohio ...do... Dolomite, Lemont, HI Brown sandstone, Springfield, Central Music Hall State House Post-office and court-house Windsor Hotel Union Depot Union Pacific Freight Depot Rio Grande Depot State capitol building 1 Stevens Institute building State Mining School buildings. . , Court House State House Court House , St. Patrick's Cathedral State capitol building U. S. Custom House Converse Memorial Library Wesleyan University buildings. "Washburne Flouring Mills Dolomite, Lemont, HI Granite, near Columbia, S. C Granite, Winnsborough, S. C Rhyolite-tuff, Douglas County, Colo ...do .do. .do. Sandstone, Gunnison, Colo Diabase, Jersey City Sandstone, Portage Entry, Mich. Bedford Oolite \.. ...do... Diabase, Jersey City do ... Sandstone, Amherst, Ohio , Bedford Oolite Sandstone, East Long Meadow, University of Minnesota Universalist Church City hall Westminister Presbyterian Church. Custom-House. do... Brown sandstone, Portland, Conn Magnesian limestone, Minneapo- lis, Minn. do .do. .do. State capitol Custom - house and post - o ffi c e building. County court-house Custom-house Monument to General Robert E. C Lee. I Colunibia College Trinity Church, Broadway and Wall street. Lenox Library, Fifth avenue and Seventieth street. Hospital, Sailors' Snug Harbor, Staten Island. Ludlow street jail Brown sandstone, Fond dti Lac,, Minn. Granite, Quincy, Mass Oolitic limestone, Bowling Green, Limestone near Nashville, Tenn.. Sandstone, Little Falls, N. J .do. Granite, Quincy, Mass Granite, Georgia Gray marble, Knoxville, Tenn Red sandstone, Potsdam, N. Y Brown sandstone, LittleFalls, N. J. Limestone, Lockport, N. Y. Granite, Spru< .1880 1873-'85 1881-'83 1858 1883 1859 1872 426 APPENDIX III. LIST OF SOME OF THE MORE IMPORTANT STONE STRUCTURES OF TEE UNITED STATES Continued. Locality. Structure. Material, Date of erec- tion. New York City New York City and Brooklyn. Philadelphia, Pa,... Portland. Me Sails of justice or " Tombs " Seventh Regiment armory Metropolitan Museum of Art S"ew York post-office ourt-house in City Hall Park. . . . Astor House Reformed Church, La Fayette Place. Egyptian obelisk in Central Park . St. Patrick's Cathedral (in part).. Old city hali, east, south, and west fronts. Treasury building, Wall street . . St. Patrick's Cathedral (in part). Stock Exchange St. Patrick's Cathedral (in part) . Union Dime Savings Bank . do . Granite, Round Pond, Me. Granite, Mt. Desert, Me . . Granite, Dix Island, Me .. do Granite, Quincy, Mass do 188$ Hornblende granite, Egypt ' Dolomite (marble), Leo, Mass I Dolomite (marble), West Stock bridge, Mass. -do Fortifications, Fort Richmond... Fortifications, Fort Lafayette Fortifications at Willets Point . . Fortifications at Governor's Isl- and. Fortifications at Bedloe's Island. Fortifications at Ellis Island Fortifications, Fort Schuyler, Throgg's Neck. Fortifications, Fort Wadsworth, Staten Island. Fortifications, Fort Hamilton Fortifications, Fort Diamond Dolomite (marble), Tuckahoe.N.Y. do "Snowflake" marble (dolomite), Pleasantville, N. Y. Marble (dolomite), Pleasantville, N. Y. Granite, Dix Island, Me Brown sandstone, New Jersey . . . Granite, Spruce Head, Me ...do .do. .do. Gneiss New York and Brooklyn bridge. Girard Bank. United States custom-house United States mint United States Naval Asylum Merchants' Exchange Girard College Philadelphia National Bank First National Bank Now Masonic Temple New Post-Office St. Mark's Protestant Episcopal Church. Bank of Commerce Bank of North America Holy Trinity Episcopal Church . Fifth Baptist Church New city buildings University of Pennsylvania Memorial Baptist Church Holy Communion Church Academy of Natural Sciences . . - Young Men's Christian Associa- tion. Forts Preble, Scammel, and Gorges Post-office Granite, Maine. Granite, Frankfort, Me.; Concord, N.H.; Spruce Head, Me.; Cape Ann, Mass.; Hurricane Island, Me.; Westerly, R. I.; East Blue- hill, Me.; Stony Creek, Conn.; Mt. Desert Island, Me.; Chance- burgh, N. J. Limestone, Rondout, N. Y.; King- ston, N. Y.; Isle La Motte, Lake Champlain; Willsborough Point, Lake Champlain; near Catskill, N. Y. Limestone (marble), Montgomery County, Pa. do 1819 do 1829 do 1830 do 18:2 do 1833 Granite, Quincy, Mass 1850-'eO . .. do I 18fK> Granite, Fox Island, Me.; Cape 1872 Ann, Mass. Granite, Dix Island, Me.; Rich- 1883 mond, Va. Sandstone, Portland, Conn 1849 1798 .do. .do. .do. do. Dolomite (marble), Lee Mass Serpentine, Chester County, Pa. do. do do Sandstone, Ohio. Granite, Mount Waldo, Biddeford, and Spruce Head, Me. Crystalline limestone (marble), Vormout. 1830 1850 1857 1863 "l871 1874 1875 187G 1868 1872 APPENDIX III. 427 LIST OF SOME OF THE MORE IMPORTANT STONE STRUCTURES OF THE UNITED STATES Continued. Locality. Structure. Material. Date of erec- tion. Providence, R. I Saint Paul, Minn. Salt Lake City, Utah San Francisco, Cal... Savannah, Ga Trenton, N. J Washington, D. C . . Custom-house. City hall Soldiers' and sailors' monument . - Post-office and custom-house Roger "Williams's monument New Catholic cathedral Grace Church First Congregational Church Catholic cathedral 'Unitarian church St. Paul's Episcopal church United States custom-house and post-office. Adams school Franklin school County jail Assembly house New Mormon Temple. Bank of California... United States mint Granite, Hallowell, Me., Concord, N. H. Granite, Hurricane Island, Me.; Westerly, K. I., and Concord, N.H. ' Granite, Westerly, R. I Granite, Quincy, Mass Granite, Westerly, R. I Sandstone, Portland, Conn Sandstone, Little Falls, N. J Granite. Smithfield, R. I Magnesian limestone, Saint Paul, Minn. ...do... 1872 1858 Magnesian limestone, Elasota, Minn. ...do... 1873-74 1872 Granite, Little Cottonwood Caiion, Utah. ...do... Presbyterian church. Custom-house . . Blue sandstone, Angel Island, San Francisco Bay. Sandstone, New Castle Island, Gulf of Georgia, British Colum- bia. Granite, Quincy, Mass 1865 1874 State capitol State prison Executive Mansion Treasury Building, old portion... Treasury Building, new portion. . . Patent Office Building, old portion. Patent Office Building, extension. Chapel in Oak Hill Cemetery Georgetown College (new build- ing.) Cabin John's Bridge, parapets and coping. Washington Monument, exterior, in part. Washington Monument, exterior. Washington Monument, interior. . General Post-Office, old portion. . General Post-Office, extension United States Capitol, old portion United States Capitol, extension. United States Capitol, extension, columns. Smithsonian Institution St. Dominick's Church Corcoran Art Gallery (in part) . . . State, War, and Navy Building. .do. Sandstone, Trenton, N. J. do Sandstone, Acquia Creek 1852 .do- Granite, Dix Island, Maine Sandstone, Acquia Creek, Va. . . . Dolomite (marble), Cockeysville, Md. Mica schist, near Washington . . . ...do... 1836 '41 1855 1837-'42 1849-'64 Bntler house, Capitol Hill Congressional Library building.. Sandstone, Seneca Creek, Md ] Dolomite (marble), Lee, Mass.. f Dolomite (marble), Cockeysville. Md. Mica schist, near Washington ; granite, Massachusetts and Maine. Dolomite (marble) , West Chester, N.T. Dolomite (marble), Cockeysville, Md. Sandstone, Acquia Creek Dolomite (marble;, Lee, Mass . . Dolomite (marble), Cockeysville, Md. Sandstone, Seneca Creek, Md Gneiss, Port Deposit, Md Sandstone, Belleville, N. J Basement and sub-basement gran- ite.Maine ; superstructure gran- ite, near Richmond, Va. Granite, Cape Ann, Mass , Granite, Concord, N.H 1848-'55 1848-'84 1839 1855 1793 1851-'65 1847-'5G 1871-"'86 Begun . . . 1890 APPENDIX IV. BIBLIOGRAPHY OF WORKS ON BUILDING STONE. The following list includes all the principal works on the subject of building stone which have come under the writer's notice. It does not include isolated and special papers which have appeared from time to time in various journals and per- iodicals, or State geological reports. Such, when containing matter of sufficient importance, have been mentioned in the text and reference given in the foot-notes. The list is arranged alphabetically by authors. BLUM, Dr. J. REINHARD. Lithurgik oder Mineralien und Felsarten nach ihrer Anvvendung in okonomischer, artistischer und technischer Hinsicht sys- tematisch abgehandelt. Stuttgart, 1840. BOHME, Dr. Die Festigkeit der Baumaterialien. Resultate der Untersuchungen in der Station zur Priifung der Festigkeit von Bausteinen an der konig- lichen Gewerbe-Akademie zu Berlin, etc. Berlin, 1876. BURGOYNE, Sir JOHN. Rudimentary Treatise on the Blasting and Quarrying of Stone. London: J. Wale, 1852. BURNHAM, S. M. History and Uses of Limestone and Marbles. Illus- trated, with colored plates. Boston: S. E. Cassino & Co., 1883. CHATEAU, THEODORE. Technologic du Batiment ou Etude Complete des Materiaux de toute EspSce employes dans les constructions, etc. 2. ed. Paris, 1880. DAVIES, D. C. Slate and Slate Quarrying. London: Crosby, Lockwood & Co., 1878. DELESSE, A. Materiaux de Construction de 1'Exposition Universelle de 1855. Paris, 1856. DOBSON, EDWARD. Masonry and Stone-cutting. Weaie's Rudimentary series. London: Crosby, Lockwood & Co., 1873. 428 APPENDIX IV, 429 GERSTENBERGK, HEINRICH VON. Katechismus der Baumaterialkunde, etc. Berlin, 1868. GOTTGETREU, RUDOLPH. Physische und Chemische Beschaffenheit der Baum- aterialien. 2 vols. Berlin, i88o-'8i. Verlag von Julius Springer. GRUEBER, BERNHARD. Die Baumaterialien-Lehre. Berlin, 1863. Verlag von Ernst & Korn. GWILT, JOSEPH. An Encyclopedia of Architecture. London, 1851. HALL, PRO!. JAMES. Report on Building Stones. HARRIS, GEORGE F. Granite and our Granite Industries. London: Crosby, Lockvvood & Son, 1888. HARTMANN, Dr. CARL. Vollstandiges Handbuch der Steinarbeiten, etc. Weimar, 1862. HAUENSCHILD, HANS. Katechismus der Baumaterialien. Wien: Lehmann & Wentzel, 1879. HULL, EDWARD. A Treatise on the Building and Ornamental Stones of Great Britain and Foreign Countries. London: Macmillan & Co., 1872. KERSTEN, E. Die Baumaterialienkunde, etc. Leipzig (not dated). Verlag von Eduard Hahnel. KOLLSCH, CARL. Die Baumaterialienkunde fur ausflihrende Bautechniker und fiir Studirende der Bauwissenschaft. Schvvetschke & Sohn. Bruhn, 1861. KUNZ, GEORGE F. Gems and Precious Stones of North America. Scientific Publishing Company, New York. 1890. MALECOT, LEON. Materiaux de Construction employes en Belgique. Bruxelles & Liege, 1866. NEWBERRY, J. S. Building and Ornamental Stones. Report of Judges, Group i, U. S. International Exposition, 1876, Vol. ill. Washington, 1880. Notes on Building Construction. Part in. Materials. (South Kensington Educational Series). London, Oxford, and Cambridge, 1879. SCHLEGEL, CARL FRIEDRICH. Die Lehre von den Baumaterialien und den Arbeiten der Maurer. Leipzig: Verlag von Heinrich Matthes, 1857. SCHMIDT, OTTO. Die Baumaterialien. Berlin, 1881. Verlag von Theodor Hofmann. SMOCK, JOHN C. Building Stone in the State of New York. Bulletin No. 3, New York State Museum of Natural History, March 1888, 8vo, 152 pp. Report on the Building Stones of the United States, and Statistics of the Quarry Industry for 1880. Vol. x. Report of the Tenth Census of the United States. Washington: Government Printing Office, 1884. THURSTON, R. H. Materials of Construction. New York: Wiley & Sons, 1885. VIOLET, ADOLPH. Les Marbres et les Machines atravailler le marbre. (Rap- ports sur 1'Exposition de 1878, xxvin.) Paris, 1879. 430 APPENDIX IV. VISSER, J. E. Die Baumaterialien. Handbuch fur Architecten, etc. Emden, 1861. WEBBER, MARTIN. Das Schleifen, Poliren, Farben und kiinstlerische Verzieren des Marmors. Weimar, 1878. Bernhard Friedrich Voigt. WENCK, Dr. JULIUS. Die Lehre von den Baumaterialien, etc. Berlin, 1863. The works mentioned below bear upon the subject only indirectly. They are given up largely to metals and timber. ANDERSON, JOHN. The Strength of Materials and Structures. London: Long- mans, Green & Co., 1880. BARLOW, PETER. A Treatise on the Strength of Materials, etc. New Edition; revised. London: Lockwood & Co. 1867. B5HME, Dr. Die Festigkeit der Baumaterialien. Berlin, 1876. GILLMORE, L. A. Notes on the Compressive Resistance of Freestones, Brick Piers, Hydraulic Cement, Mortars and Concretes. New York, Wiley & Sons, 1888. MORIN, ARTHUR. Resistance des Materiaux. Paris: L. Hachette &Co., 1862. APPENDIX V. GLOSSARY OF TERMS. JEolian rocks. Fragmental rocks, composed of wind-drifted materials. The "drift sand rock," the common building-stone of Bermuda, is a good example. Argillaceous. Containing clayey matter. Ashlar masonry. Cut stone laid in continuous courses. Bardiglic. This is a favorite Italian marble obtained on Montalto, on the southern borders of Tuscany. It is a gray or bluish color, traversed by dark veins. In some specimens the veining assumes the appearance of flowers, when it is known as Bardiglio fiorito. The name is now com- monly applied to any marble having this color and veining. Bastard granite. A somewhat indefinite name given by quarrymen to gneissic or schistose rocks, resembling granites in a general way, but differing in structure. The name ^s frequently applied by quarrymen to any vein or dike rock occurring in a granite quarry. Bird's-eye-marble. A term used in Iowa to designate a fossil coral (Acerv- ularia davidsoni), and used for making small ornaments. Bituminous. Containing bitumen. Breast. The face or wall of a quarry is sometimes called by this name. Breccias. Fragmental stones, the Individual particles of which are large and angular in form. Bluestone. In Maryland a gray gneiss ; in Ohio, a gray sandstone ; in the District of Columbia a mica schist ; in New York a blue-gray sandstone ; in Pennsylvania a blue-gray sandstone. A popular term ; not suffi- ciently definite to be of value. Butt. The butt of a slate quarry is where the overlying rock comes in contact with an inclined stratum of slate rock. Calcareous. Containing lime. Cavernous. Containing irregular cavities or pores, due in most cases to the removal of some mineral, or in limestones of a fossil. Cellular or vesicular. Containing cells or vesicles. This structure is very 431 43 2 APPENDIX V. common in recent eruptive rocks, especially the glassy forms. Some- times the stone contains so many cells that it will float on water, as is the case with common pumice. These cells are in many cases subse- quently filled with other minerals, and the rock is then called amygda- loidal. The Brighton melaphyr is the best example of amygdaloidal - structure found in our building stones. Choncoidal fracture. When the surfaces of a chip broken off by a hammer are curved like a bivalve mollusk the stone is said to have a choncoidal fracture. Compact stones, like lithographic limestones, obsidians, and flints, usually break in this manner. Clay-holes. Cavities in stone which are usually filled with fine sand or clayey material often of a lighter color than the stone itself, and so loosely coherent as to fall away immediately or to weather out on exposure. They are especially prevalent "in many of our Triassic sandstones, and, besides being unsightly, are elements of weakness and should always be avoided. Concretionary. Made of concretions, or rounded particles formed by the col- lecting of mineral matter around some centre so as to form a rounded mass composed of concentric layers like the coatings of an onion. When the concretions are small, like the roe of a fish, the structure is called oolitic, or if large as a pea, pisolitic. The best examples of this struct- ure in our building stones are the oolitic limestones of Bedford, Indi- ana, and other places. A rare structure in crystalline rocks. Conglomerates. Fragmental stones composed of large, rounded fragments. (See p. 248.) Coquina. The Spanish name for a shell limestone which occurs abundantly in Florida, and composed simply of a mass of shells cemented together. (See p. 123.) Coral limestone. A rock composed of fragments of corals. Crystalline. Consisting wholly of crystals or crystalline particles, not frag- mental. Rocks which like granite or crystalline limestone are made up wholly of crystalline grains are called crystalline-granular or granular- crystalline rocks. The term micro-crystalline and crypto-crystalline are often applied to rocks in which the individual particles are too small to be readily distinguished by the unaided eye. Such rocks are sometimes called compact, a term which is also applied to fragmental rocks of simi- lar texture. Curb. A flat piece of stone placed vertically, bounding the street edges of sidewalks. Diabase. An eruptive rock composed essentially of a plagioclase feldspar and augite. (See p. 228.) APPENDIX V. 433 Dikes (or dykes). Masses of igneous rocks which have been forced up from below in a molten condition to fill fractures or fissures in the earth's crust. Such are also called trap-rocks. The diabases and a variety of eruptive rocks frequently occur in the form of dikes. Diorite. An eruptive rock composed essentially of a plagioclase, feldspar and hornblende. (See p. 239.) Dip. The slope or pitch of the strata, or the angle which the layers make with the plane of the horizon. Dolomite. A stone composed of mixed calcium and magnesium carbonates. (See p. 83.) A "Dry." A natural seam usually invisible when the rock is freshly quarried, but which is brought out on exposure to weather or sometimes during the process of cutting. A very serious defect in many stones. Escarpment. A nearly vertical natural face of rock or ledge. Feldspathic. Containing feldspar. Ferruginous. Containing iron oxides. Fibrous. Having a structure as though made up of bundles of distinct fibres. This structure is not found in any building stone, but is common in some forms of gypsum and of calcite, which are used for making small orna- ments. Flagstone. Any kind of a stone which separates naturally into thin tabular plates suitable for pavements and curbing. Especially applicable to sandstones and schists. Flint. Quartz in any kind of rock is commonly known to quarrymen as flint. True flint is amorphous silica, occurring in nodular form in chalk beds. Foliated or schistose. Terms applied to rocks which, like gneiss and schist, have their constituents arranged in more or less definite nearly parallel planes. Fragmental or clastic. Terms which are applied to rocks composed of frag- ments, like ordinary sandstone. When the fragments are the size of a pea or larger, and rounded in form, the structure is called conglomerated, or if the particles are angular, brecdated. Freestone. This is a term which has been applied to stones that work freely in any direction. Especially applied to sandstones and limestones. A term of no special value, as it is too indefinite. Gneiss. A rock of the composition of granite but in which the ingredients are arranged in more or less parallel layers. (See p. 244.) Gneissoid* Like gneiss. Grain. The direction in a rock at right angles with the rift. (See p. 39.) Granite. A rock consisting of quartz, orthoclase, and mica or other accessory minerals. In the stone-cutter's nomenclature no distinction is made 434 APPENDIX V. between the varieties ; all stones which are hard, granular, and crystal- lized are called granite. (See p. 175.) Granitoid. Thoroughly crystalline and massive, like granite. Granular. A term applied to rocks composed of distinct grains, whether frag- mental and water worn or crystalline. Greenstone or Griinstein. A term formerly used to designate certain basic eruptive rocks occurring in the form of dikes. Through mistaken notions regarding their true nature and from a general similarity in their appearance the name was made to include a variety of compact, dark- greenish or nearly black rocks, which microscopic examination has shown to be principally diabase and diorite. Grit. Any sharp, gritty sandstone or schist used as a whetstone or hone. Grub-saw. A saw made from a notched blade of thin iron, and provided with a wooden back. Used with sand for sawing stone by hand power. (See Plate xi.) Guys. Ropes or chains used to prevent anything from swinging or moving about. Hackly fracture. A term applied when the surfaces of a fracture are rough and jagged. Joints. Divisional planes which divide the rock in the quarry into natural blocks. There are usually two or three nearly parallel series called by quarrymen end joints, back joints, and bottom joints, according to their position. (See p. 316.) Ledge. Any natural solid body of rock. Lewis hole. The Lewis * hole consists of a series of two or more holes drilled as closely together as possible, and then connected by knocking out the thin partition between them, forming thus one wide hole, having its greatest diameter in a plane with the desired rift. Blasts from such holes are wedge-like in their action, and by means of them larger and better-shaped blocks can be taken out than would otherwise be possible. This style of hole is saidf to have been devised by a Mr. Joseph Rich- ards, of Quincy, though at about what date we are not informed. This same gentleman was also the inventor of the bush hammer, which, how- ever, when first patented, about 1831, consisted of a solid piece, instead of several pieces bolted together as now. Limestone. Under this term almost all the calcareous quarried rocks, whether fragmental or crystalline, are classified. (See p. 78.) Liver rock. This term is applied to that variety of the Ohio sandstone which * This word is spelled by some Louis. f Potter's History of Quincy, Massachusetts. APPENDIX V. 435 breaks or cuts as readily in one direction as in another. In other words, the working of the stone is not affected by stratification. Lyonaise marble. A local term applied to marbles which are composed of a mixture of red and white colors, as those of Mallet's Bay, Vermont. Marble. Any limestone or dolomite capable of being polished and suited for ornamental work. Massive ; unstratified. Having no definite arrangement in layers or strata, but the various ingredients being thoroughly commingled, as in granite and diabase. Nigger head, (i) The black concretionary nodules found in granite ; (2) Any hard, dark, colored rock weathering out into rounded nodules or bowlders ; (3) Slaty rock associated with sandstone. A quarryman's term. Oolite. A stone composed of small globules resembling the roe of a fish. Ophiocalcite, ophiolite, or ophite. A mixture of serpentine and limestone or dolomite. (See p. 53.) Peroh. In Philadelphia, 22 cubic feet are called a perch. A perch of masonry, contains 24! cubic feet, 16^ x if x I. It is usually taken at 25 cubic feet. The term is falling into disuse. Plucky. A term often used by stone-cutters to designate stones which under the chisel break away in irregularly conchoidal chips, and which are therefore difficult to trim to a line or to bring to a perfect surface. Com- mon in compact and impure limestones. Porpjjyry. Any stone composed of an extremely fine ground mass in which larger crystals are developed. (See p. 217.) Porphyritic. When a rock consists of a compact or fine and evenly crystal- line groundmass, throughout which are scattered larger crystals, usually of feldspar, the structure is said to be porphyritic. This structure is quite common in granite, but is not particularly noticeable, owing to the slight contrast in color between the larger crystals and the finer groundmass. It is most noticeable in such rocks as the felsites, in which, as is the case with some of the "porphyries" of eastern Massa- chusetts, the groundmass is exceedingly dense and compact and of a black or red color, while the large feldspar crystals are white and stand out in very marked contrast. This structure is so striking in appearance that rocks possessing it in any marked degree are popularly called por- phyries whatever may be their mineral composition. The term porphyry is said to have been originally applied to certain kinds of igneous rocks of a reddish or purple color, such as the celebrated red porphyry or "roseo antico" of Egypt. The word is now used by the best author- APPENDIX V. ities almost wholly in its adjective sense, since any rock may possess this structure whatever its origin or composition may be.* Putty powder, or polishing putty, is a fine whitish powder, consisting in the commercial form of about equal parts oxide of tin and lead. Used in polishing stone and glass. Quarry. Any opening in a ledge for taking out stone. Quarry Water. All rocks when first taken from the quarry contain more or less water, which evaporates on exposure, leaving the stone considerably harder. In sandstones this quarry water is considered by Newberry to be a solution of silica (" Report of Judges," Group i. p. 127). Its com- position probably varies greatly in different, classes of rocks. See P. 363- Rhyclite. A post-Tertiary volcanic rock of the composition of granite. See p. 221. Rift. The direction in a rock parallel to the lamination or foliation, and along which it splits with greatest ease. Rubberstone. A sharp-gritted Ohio or Indiana sandstone used for sharpening shoe-knives ; also called a shoe-stone. Rubble masonry. Rough, unsquared stone laid in irregular courses. Saccharoidal. Having a grain and structure like that of loaf sugar. Common in crystalline limestone. Salt veins. A term applied by the quarrymen to the coarse granite veins from 2 inches to 2 or more feet thick, and which are found intersecting gran- ites and older crystalline rocks. Scab. A local term used in certain sandstone quarries in Iowa. The stone is very massive and is broken from the quarry in irregular lumps by blast- ing. These lumps are then trimmed down to a shape approximately rectangular by means of heavy picks. This process is denominated scabbing. Sap. The term originated from imagined analogy between the decomposed layer and the sap wood of trees. A term applied to the stained and worthless portions of the stone extending inward from the joint. Sculp. To sculp slate is to break up the large blocks into long slabs, suitable to split. Segregated. A term applied to the veins and nodular masses of finer or coarser texture that have formed in granite and other crystalline rocks ; as for example, the black patches in granite. Serpentine. A rock composed of hydrous magnesia silicate. (See p. 53.) Shell limestone. Rock composed of consolidated shells. * Hull, " Building and Ornamental Stones," p. 75. APPENDIX V. 437 Siliceous. Containing silica. Spalls. This is a term which is used quite generally by stone-cutters to denote the chips and other waste material cut from a block in process of dress- ing. Spider-web. A term applied to the wavy lines in the Ohio sandstones, and which are caused by stains of iron oxide. Frequently seen in sawed stones, especially where the lamination is slightly oblique or irregular. It is very like the grain of wood which shows in a planed board. (See p. 277.) Split rock. This term applies to those rocks possessing tabular structure, or which cleave easily in the lines of lamination, and are consequently applicable to the preparation of flagging and for curbstones. Stalactite or Stalagmite marble. This is a marble which is formed by the deposit of lime carbonates from waters percolating into cavities or caves. Strata. Layers or beds of rock of the same kind lying one upon another. Stratified; bedded. Composed of layers or beds lying parallel to one another, as is so frequently seen in sandstone and limestone. When the strata are fine and leaf-like the structure is called laminated or shaly. Streaked. Having some of the mineral constituents so arranged as to give the rock a striped or streaked appearance. In the eruptive rocks this structure is often produced by the flowing of the mass in a partially cooled condition. It is best seen in obsidian, rhyolite and quartz por- phyries. Stock. The useful rock taken from a quarry. Strike. The direction in strata at right angles to the dip, or the course of a horizontal line on the surface of inclined beds. Syenite. A granular massive rock with the structure of a granite, but con- taining no quartz. (See p. 223.) Trachyte. A post-Tertiary volcanic rock of the composition of syenite. (See p. 226.) Trap or trap-rock. (See Dikes and Greenstone.) The name applies to the manner in which a rock occurs, and is not itself a name of specific value. Travertine. A calcareous rock deposited by water from solution, and which was used as a building stone in Rome. (See text, p. 116.) Verde antique. Antique green. A rock composed of a mixture of serpentine and limestone. (See p. 54.) Vitreous or glassy. These terms are applied to rocks that have a structure like glass, as obsidian. Rocks of this type are at present little used for any kind of work. INDEX. Aberdeen granite, 216 Abrasion of stone by wind-blown sand, 357 Absorption, ratio of, 385 Absorption tests, value of, 386 Absorption of water by sandstone, 371 Accessory minerals of rocks, 17 Acervularia davidsoni, 92 Acid gases, effects on sandstone, 372 Acid gloss surface, 334 Adaptability of liparites for construc- tion, 221 Addison, Maine, diabase, 231 Africa, marbles of, 152 Agalmatolite, 167 Aggregation, state of, 38 Alabama, limestones in, 122 Alabama, marble in, 84 Alabama, resources of, 15 Alabama, sandstone of, 249 Alabaster, Italy, 77 Alabaster, method of making opaque, 78 Alabaster, Spain, 78 Alexander column, cause of disintegra- tion, 366 Algeria, marbles of, 152 Algerian onyx, 120 American marbles, defects in, 383 Amherst quarries, section of, 277 Amianthus, 54 Amphibole, properties of, 24 Andesites, the, 243 Andesites, uses of, 243 Antique porphyry, 229 Aplit, 179 Aragonite, properties of, 26 Argillaceous fragmental rocks, 293 Argillite, Montana, 169 Arizona, onyx of, 118 Arizona, resources of, 15 Arizona, sandstone of, 249 Arkansas, sandstone of, 250 Arkansas, slates of, 299 Arkansas, syenite of, 225 Arkansas, limestones of, 122 Arkansas, marbles of, 84 Arkansas, soapstone of, 47 Arkansas, resources, 15 Arkose, 249 Artificial heat, effect on stone, 356 Atmosphere, chemical action of, 360 Atmosphere, composition of, 359 Aughey, Prof., quoted, 140 Ausable granite, see Norite, 236 Austria, marbles of, 160 Ax or pean hammer, 348 Azurite, see Malachite, 170 Ax-hammered face, 333 Back joints, 317 Barcena, M. M., quoted, 119 Bardiglio marble, 164 Barre, granite of, 211 Basalt, 239 Basalt, California, 239 Bastard granite, 177 Bastard granite, see Gneiss, 244 Batchen, J. S. F., quoted, 264 Bath oolite, 155 Bay of Fundy granite, 215 Bedding in stone, importance of, 314 Bedford oolite, 129 Belgian black marble, 157 Belgium, marbles of, 157 439 440 INDEX. Berea grit in Ohio, 275 Berea sandstone, qualities for grind- stones, 276 Berea sandstone, mellowing of, 276 Bermuda, limestones of, 150 Bermuda limestone, method of quarry- ing, 150 Bibliography of works on building- stone, 428 Bituminous dolomite, Cook County, . 126 Black granite, see Diabase, 232 Black and gold marble, 165 Black marble, Italian, 165 Black marble of Glens Falls, N. Y., 28 Black marble of Isle La Motte, 113 Black marble of Italy, 163 Bluestone of New York State, 271 Bohme, Dr., experiments on stone, 39 Bonney, T. G., referred to, 73 Boston Court House, date of erec- tion, 2 Bottom joints, 317 Bougard marble, 160 Bowlders on Quincy Commons, 2 Brainard, Prof., quoted, 105 Branner, Prof. J. C., quoted, 225, 250 Brard's process of testing stone, 387 Breccia, 248 Breccia marble, 92, 162 Breccia marble, Italian, 165 British Columbia, granite of, 214 British Columbia, marbles of, 151 British Columbia, sandstones of, 289 Broadhead, Prof., quoted, 200 Brocatelle marble, 159, 165 Brocatelle, origin of name, 160 Building-stone, works on, 428 Bunker Hill Monument, swaying of, 353 Bush-hammer, 348 Bush-hammered finish, 334 Caen stone, 159 Caffal process of preserving stone, 400 Calcite, properties of, 25 Calc sinter defined, 80 California, basalt of, 239 California, granites of, 180 California, liparite of, 223 California, marbles of, 85 California, onyx marble of, 117 California, quartz diorite of, 242 California, resources of, 15 California, sandstone of, 251 California, slates of, 299 California, serpentine of, 57 California, soapstone of, 47 Canada, granites of, 214 Canada, marbles of, 151 Canada, serpentine of, 72 Canada, slates of, 312 Carbonic acid in atmosphere, 359 Carlisle stone, 290 Catlinite or Indian pipestone, 168 Cavities in quartz, effects of, 367 Chalk defined, 82 Chamberlain, T. C., quoted, 213 Channelling machine, 321, 336 Channelling machine, capacity of, 339 Channelling machine, arrangement of drills, 339 Chateau, quoted, 242 Chauvenet, Prof., method of testing stone, 393 Chemical action of atmosphere on stone, 360 Chemical agencies affecting rocks, 359 Chemical characters of rocks, 41 Chemical composition of building- stone, tables, 414 Chemical composition of liparite, 222 Chelmsford, early quarries, 2 Chilled iron, used in stone sawing, 345 Chisel or drove, 349 Chisels used in stone-working, 349 Chlorite, properties of, 28 Chloritic schists, 245 Chrysotile, 54 Clay slates, 293 Clay slate, early quarrying of, I Classification of rocks, 42 Coefficient of expansion of minerals, 366 Cold, effect of, on stone, 353 Color of rocks, cause of, 40 Colorado, diorite of, 242 Colorado, granites of, 182 Colorado, limestones of, 122- Colorado, marbles of, 88 Colorado, resources of, 15 Colorado, sandstones of, 254 INDEX. 441 Colorado, slate of, 299 Collett, Prof., quoted, 260 Compact common limestone defined, 80 Comparative durability of stones, 380 Composition of atmosphere, 359 Composition of building-stones, tables, 414 Composition and origin of porphyry, 217 Concord granites, 202 Concretionary nodules in granite, 193 Conglomerate, 248 Conglomerate of Roxbury, Mass., 263 Connecticut, diabase of, 231 Connecticut, granites and gneisses of, 182 Connecticut, marbles of, 89 Connecticut, resources of , 15 Connecticut, sandstone of, 257 Connecticut, serpentine of, 58 Connecticut, trap ridges in, 230 Conover, Prof., quoted, 123 Connemara green serpentine, 74 Cook, Prof., quoted, 269 Coquina, 123 Coral rock defined, 82 Coral shell marble, 143 Corsica, kugel diorite of, 241 Cost of cutting stone, table, 422 Crahdall, the, 348 Crinoidal limestones defined, 8r Crosby, Prof. W. O., quoted, 319 Crushed steel for stone-sawing, 345 Crushing strength of building-stone, tables, 404 Crystalline limestone; marble, 80 Cubes for testing strength of stone, preparation of, 386 Curly slates, 297 Cutting and dressing stone, methods of, 323 Dacite, 243 Dakota, slate of, 299 Dana, J. D., quoted, 170, 230 Deacon John Phillips, house of, I Dedham pink granite, 197 Defects in marbles, 382 Delaware, gneisses of, 183 Delaware, marble of, 89 Delaware, resources of, 15 Delaware, serpentine of, 60 Delesse, referred to, 121 Density and hardness of stone, 32 Deoxidation, effect on stone, 362 Diabase, 228 Diabase, Connecticut, 231 Diabase dikes and sheets, distribution of, in the eastern U. S., 229 Diabase, Maine, 231 Diabase, Massachusetts/232 Diabase, New Jersey, 232 Diabase, Missouri, 232 Diabase, Pennsylvania, 234 Diabase, strength of, 235 Diabase, Virginia, 234 Diamond channelling machine, 340 D'Invilliers, E. V., quoted, 280 Diorites and kersantites, 239 Diorite, Colorado, 242 Diorite, composition of, 240 Diorite, derivation of name, 239 Diorite, New Hampshire, 241 Diorite, poor working qualities of, 240 Diorite, Texas, 241 Diorite, uses of, 240 Dip joints, 316 Discoloration of stone through absorp- tion of water, 396 Distribution of building-stone in the U. S., 10 Dix Island granite, 190 Dolomite defined, 83 Dolomitic limestones defined, 82 Dolomites and limestones, compara- tive durability, 380 Dolomite marble, Maryland, 92 Dolomite marble, Lee, Massachusetts, 94 Dolomite, origin of name, 83 Dolomite, properties of, 26 Dolomite, weathering properties of, 368 Dolomite, Westchester, New York, 97 Dolomite, Will County, qualities of, 125 Dorset, Vermont, marble quarries at, 107 Dressing stone, methods, 323 Dressing stone at Quincy, old method, ,325 Drills and drilling machines, 335 Duluth granite, see Gabbro, 236 Durability of Egyptian granite, 376 442 INDEX. Durability of stone affected by manner of dressing, 397 Diamond gadding machine, 341 East Blue Hill granite, 187 Eclipse rock drill, 335 Effects of freezing on stone, tests of, 387 Efflorescence on stone, 397 Egleston, Prof. T., quoted, 357 Egyptian granite, 214 Egyptian onyx, 120 Egyptian obelisk, disintegration of, 366 Egyptian obelisk, method of preserva- tion, 400 Elseolite syenite, Arkansas, 225 Elaeolite syenite, Maine, 226 Eldridge, George H., quoted, 254 Emerson, Prof. B. K., quoted, 242 End joints, 316 England, granite of, 216 England, gypsum (alabaster) of, 77 England, marbles of, 154 England, serpentine of, 72 Eolian marble, 106 Eozoon canadense, 66 Epidote granite, 197 Epidote, properties of, 28 Essential minerals of rocks, 17 Euclid bluestone, 278 Europe, marbles of, 157 Exfoliation of stone caused by sun's heat, 354 Face-hammer, 347 Feldspars, the, properties of, 21 Feldspar porphyry, 218 Ferrous carbonate in sandstone, 361 Field, Dr., quoted, 3 Fine sand finish, 334 Finland, stone-quarrying in, 326 Finish, kinds of, 333 Fire-resisting properties of stone, 356 First stone building in Boston, i First stones quarried in Massachusetts, i Florida, limestones of, 123 Florida, resources of, 15 Formosa marble, 160 Foreign sandstones, 287 Foreign serpentine, 72 Foreign slates, 312 Fort Marion, construction of, 123 Fossil coral, acervularia davidsoni, 169 Fossiliferous limestones defined, 81 Fossiliferous stones to be avoided, 381 Fossil wood, 173 Fourche Mountain syenites, 225 Fox Island granite, 188 Fragmental rocks, 245 Frankfort Granite Co. began work, 5 France, marbles, 158 Frazer, Persifer, quoted, 69, 307 Freezing stone, effects of, 355 Freezing stone, method of, 393 Freestone, 249 Freezing water, effects on stone, 387 Freezing of stone, test of effects, 287 Friction, effects of, on stone, 357 Frost, effect of, on limestones, 370 Frost, effect of, on sandstone, 371 Fusulina limestone, 132 Fusulina limestone, Nebraska, 140 Gabbro, 235 Gabbro, Maryland, 235 Gabbro, Minnesota, 235 Gadding, 322 Gadding and gadding machines, 340 Garnet, properties of, 28 Geikie, Prof. A., quoted, 369 Genth, F. A., quoted, 60 Geological record, table, 43, 44 Georgia, granites of, 184 Georgia, marble of, 89 Georgia, resources of, 15 Georgia, sandstone of, 259 Georgia, slate of, 299 German marbles, 160 Gettysburg granite, see Diabase, 234 Giallo Antico marble, 153 Gillmore, Gen. Q. A., on ratio of in- crease in strength for cubes of dif- ferent sizes, 385 Glaciated area outlined, 377 Glossary of terms, 431 Gloucester, Mass., early quarries, 3 Gloucester granites, 196 Gneiss, Connecticut, 182 Gneiss, distinction from granite, 177 Gneiss, Delaware, 183 Gneiss, Maryland, 194 Gneiss, Massachusetts, 197 Gneiss, New Hampshire, 203 Gneiss, New Jersey, 203 Gneiss, origin of name, 244 INDEX. 443 Gneiss, Pennsylvania, 208 Gneiss, Vermont, 210 Gneiss, Virginia, 212 Gneisses, use of, 244 Goode, G. B., quoted, 119 Grain of rocks, 39 Granites and gneisses, 175 Granite, British Columbia, 214 Granite, California, 180 Granite, Canada, 214 Granite, Colorado, 182 Granite, Connecticut, 182 Granite, England, 216 Granite, Egyptian, 214 Granite, Georgia, 184 Granite, Maine, 184 Granite, Maryland, 193 Granite, Massachusetts, 194 Granite, Minnesota, 198 Granite, Missouri, 199 Granite, Montana, 201 Granite, New Brunswick, 215 Granite, New Hampshire, 2OI Granite, New Jersey, 203 Granite, New York, 204 Granite, North Carolina, 205 Granite, Nova Scotia, 216 Granite, Rhode Island, 208 Granite, Scotland, 216 Granite, South Carolina, 209 Granite, Tennessee, 209 Granite, Texas, 210 Granite, Utah, 210 Granite, Vermont, 210 Granite, Virginia, 211 Granite, Wisconsin, 213 Granite, Wyoming, 213 Granite, composition and properties, 175 Granite, dark patches in, 192 Granite, derivation of name, 175 Granite, geological age, 177 Granite, mode of occurrence, 177 Granite, not a fire-proof material, 366 Granite-quarrying, 320 Granite, strength of, tables, 404 Granite, uses of, 179 Granite, weight of, tables, 404 Granite, Woodstock, 193 Granite-working, tools used, 328 Granite, varieties of, 178 Gramtell, 178 Granito di Levanto, 75 Graywacke, 249 Great Britain, slates of, 312 Greece, marbles of, 166 Greisen, 179 Grinding stone, 329 Grinding and polishing machines, 343 Grindstone Island, granite of, 204 Griotte marble, 158 Ground-mass, defined, 217 Growing organisms, effect on stone, 358 Grub saw, 350 Gypsum, alabaster, 75 Gypsum, composition and uses of, 75 Gypsum, England, 77 Gypsum, Iowa, used as a building- stone, 76 Gypsum, Italy, 77 Gypsum, localities in the U. S., 76 Gypsum, properties of, 26 Gypsum, weathering properties of, 373 Haddam Neck, Conn., early quarry- ing. 3 Hague, Arnold, quoted, 366 Hall, Prof. James, quoted, 358 Hall, Prof. James, on method of dress- ing argillaceous limestones, 398 Hall, Prof. James, on rock weather- ing, 370 Hallowell granite, 190 Hallowell, Maine, first quarries in, 4 Hammering stone, effects of, 397 Hand-drill, 349 Hand-hammer, 348 Hand-implements used in stone-work- ing, 347 Hardness of rocks, 33 Hawes, Dr. G. W., quoted, 202, 224, 293 Heat and cold, effects of, on stone, 353 Heliotrope or bloodstone, 173 Hematite, properties of, 32 Hindostan stone, 261 Historical notes, I Hitchcock, Prof., quoted, 108 Hitchcock, C. H., quoted, 201 Hornblende andesite, 243 Hornblende schist, 245 Houghton, Mich., Mining - school building, 265 444 INDEX. House of Parliament, disintegration of stone, 352 Hull, Dr. Edward, quoted, 217 Hunt, T. Sterry, on origin of serpen- tine, 54 Hummelstown quarries, section of, 280 Hummelstown, Pennsylvania, sand- stone, 280 Hurricane Island granite, 189 Hydraulic limestone, defined, 80 Hydrochloric acid in atmosphere, 359 Hypersthene andesite, 273 Idaho, marble of, 90 Idaho, resources of, 15 Idaho, sandstones of, 260 Illinois, limestones of, 123 Illinois, resources of, 15 Illinois, sandstones of, 260 Improved quarry bar, 336 Indiana, limestones of, 128 Indiana, resources of, 15 Indiana, sandstones of, 260 Indian pipestone, see Catlinite, 168 Indian Territory, resources of, 15 Induration of stone on exposure, 363 Ingersoll standard gadder, 342 Iowa, limestones of, 130 Iowa, marble of, 90 Iowa, resources of, 15 Iowa, sandstones of, 261 Irish black marble, 156 Irish marbles, 156 Ireland, serpentine of, 73 Iron in contact with stone, 397 Iron pyrite, effect of, on stone, 29-31 Iron pyrites, properties of, 29 Isle la Motte marble, 113 Italian marbles, price-list of, 423 Italy, gypsum and alabaster in, 77 Italy, marbles of, 163 Italy, serpentines of, 74 Italy, travertine of, 121 Jackson, Prof. J. W., quoted, 85-251 Jade, see Nephrite, 171 Jasper, 173 Johnson, T. H., experiments on stone, 392 i oints, causes of, 319 oints in rocks, 316 oints in basic igneous rocks, 319 Joints, importance of, in quarrying, 3i8 Julian, A. A., quoted, 270 Jumper, the, 335 Kansas, limestones in, 132 Kansas, resources of, 15 Kansas, sandstones of, 261 Kennebec Bridge, erection of, 4 Kentucky, limestones in, 134 Kentucky, resources of, 15 Kentucky, sandstones of, 261 Kersantite, 240 Kersantite, Croton Landing, N. Y., 242 Kersantite, derivation of name, 243 Kersantite, New Jersey, 242 Kersantite, qualities for structural pur- poses, 242 Kersantite, strength of, 242 Keweenaw Point sandstone, 264 Kinds of finish on stone, 333 King's Chapel, Boston, date of erec- tion, 327 King's Chapel, construction of, 2 ! King's Chapel, method of dressing stone for, 327 Kinnahan, G. H., quoted, 74, 156 Kugel diorite, 240 Kuhlman's process of preserving stone, 402 Kunz, G. F., quoted, 76 Labradorite, 169 Labradorite granite, see Norite, 236 L'albatre calcaire, 121 Languedoc marble, 159 L'Anse sandstone, 264 Lapis-lazuli, 170 Lathes and planers, 344 Laws relative to quarrying granite bowlders, 2' Leete's Island granite, 183 Lepanto marble in New York, 98 Lewis hole, 320 Lewin's process of preserving stone, 402 Limestones, Alabama, 122 Limestones, Arkansas, 122 Limestones, Bermuda, 150 Limestone, Caen, 159 Limestones, Colorado, 122 Limestone, Florida, 123 Limestone, Illinois, 123 INDEX. 445 Limestone, Indiana, 128 Limestone, Iowa, 130 Limestones, Kansas, 132 Limestones, Kentucky, 134 Limestone, Maine, 135 Limestone, Michigan, 135 Limestone, Minnesota, 136 Limestone, New York, 141 Limestone, North Carolina, 145 Limestone, Ohio, 145 Limestone, Nebraska, 140 Limestone, Pennsylvania, 147 Limestone, Tennessee, 148 Limestone, Texas, 148 Limestone, Wisconsin, 149 Limestones and dolomites, composi- tion and origin, 78 Limestone and dolomite, weathering properties of, 367 Limestones, cause of color, 79 Limestones, geological age of, 79 Limestones, mode of occurrence, 79 Liparites, rhyolites, 221 Liparite, California, 223 Liparite, localities of, in the U. S., 223 Lisbon marble, 162 List of important stone structures, 425 Lithographic limestone, defined, So Lithographic limestone, Indiana, 130 Lithographic limestone, Kentucky, 135 Lithographic limestone, Missouri, 140 Llangynog slate, composition of, 294 Louisiana, resources of, 15 Luray cave stalagmitic deposits, 115 Luxullianite, 179 Lyonaise marble, in Machines and implements used in stone-working, 335 Macroscopic structure of rocks, 33 Madrepore marble, 91 Magnesian limestone, defined, 82 Magnetite, effects of oxidation, 361 Magnetite, properties of, 31 Maine, diabase of, 231 Maine, elseolite syenite of, 226 Maine, first quarries opened, 3 Maine, granites of, 184 Maine, limestone of, 135 Maine, porphyry of, 220 Maine, resources of, 15 Maine, sandstones of, 262 Maine, serpentine of, 60 Maine, slates of, 300 Maine, soapstone of, 47 Malachite and azurite, 170 Mallet, 348 Mallett's Bay, marble of, in Marble, definition of, 83 Marbles, Africa, 152 Marbles, Algeria, 152 Marble, Alabama, 84 Marble, Arkansas, 84 Marble, Austria, 160 Marble, Bardiglio, 164 Marble, Belgium, 157 Marble, British Columbia, 151 Marble, Canada, 151 Marble, California, 85 Marble, Colorado, 88 Marble, Connecticut, 89 Marble, Delaware, 89 Marble, England, 154 Marble, France, 168 Marble, Germany, 160 Marble, Greece, 166 Marble, Idaho, 90 Marble, Iowa, 90 Marble, Ireland, 156 Marble, Maryland, 92 Marble, Massachusetts, 93 Marble, Missouri, 94 Marble, Montana, 95 Marble, Nevada, 95 Marble, New Jersey, 95 Marble, New York, 96 Marble, North Carolina, 99 Marble, Pennsylvania, 100 Marble, Portugal, 161 Marble, Spain, 161 Marble, Tennessee, 102 Marble, Texas, 104 Marble, Utah, 105 Marble, Vermont, 105 Marble, Virginia, 113 Marble, Winooski, HI Marble, Wyoming, 115 Marble beds at West Rutland, Vt., 108 Marble belt of New England, 105 Marble, black and gold, 165 Marble, brocatelle, 159, 165 Marble, Bougard, 160 Marble, durability of, in Edinburgh, 369 Marble, durability of, in New York, 369 446 INDEX. Marble, Eolian, 106 Marbles, essential qualities of, 382 Marble, Formosa, 160 Marble, French red, or griotte, 158 Marble, Georgia, 89 Marble, kinds of, in Vermont, 106 Marble, Languedoc, 159 Marble, Lyonaise, in Marble, Parian, 166 Marble, Portor, 165 Marble-quarrying, 321 Marble quarries, statistics of, 116 Marble quarries, early attempts, 5 Marble, ruin, 166 Marble, Siena, 164 Marble, yellow, 166 Marmor Lacedaemonium viride, 229 Marquette sandstone, 264 Maryland, gabbro of, 235 Maryland, granites of, 193 Maryland, marble of, 92 Maryland, resources of, 15 Maryland, sandstone of, 262 Maryland, serpentine in, 60 Maryland, slates of, 301 Maryland, soapstone of, 48 Massachusetts, diabase of, 232 Massachusetts, gneisses of, 197 Massachusetts, granites of, 194 Massachusetts, marble of, 93 Massachusetts, porphyry of, 219 Massachusetts, resources of, 15 Massachusetts, sandstone of, 263 Massachusetts, serpentine of, 62 Massachusetts, slate of, 301 Massachusetts, soapstone of, 48 Maw, Mr. G., quoted, 248 McDonald stone-cutting machine. 344, > 346 McGee, Prof. W. J., quoted, 131 Medina, sandstone of New York State, 272 Mellowing of Ohio sandstone, 360 Method of dressing stone as affecting its durability, 397 Methods of protection and preservation of stone, 395 Methods of quarrying stone, 314 Methods of testing building-stone, 384 Methods of testing stone, 392 Methods of testing stone, size of cube, 39 2 Mexican onyx, 119 Micas the, properties of, 22 Mica andesite, 243 Mica schist, 245 Michigan, limestone in, 135 Michigan, resources of, 15 Michigan, sandstone, 264 Michigan, slates of, 302 Microscopic structure of rocks, 34 Middlebury, Vt. , marble quarries, no Milford pink granite, 197 Mineral of building-stones, 17 Mineral and chemical composition of liparite, 222 Minor ornamental stones, 167 Minnesota, gabbro of, 235 Minnesota, granites of, 198 Minnesota, limestone in, 136 Minnesota, porphyry of, 220 Minnesota, quartzite of, 265 Minnesota, resources of, 15 Minnesota, sandstones of, 265 Minnesota, slate of, 303 Missouri, diabase of, 232 Missouri, granites of, 199 Missouri, marbles of, 94 Missouri, onyx marbles of, 118 Missouri, porphyry of, 220 Missouri, resources of, 15 Mississippi, sandstone of, 266 Missouri, sandstones of, 267 Modulus of elasticity, 391 Modulus of rupture, 391 Montana, argillite, 169 Montana, granites of, 2OI Montana, marbles of, 95 Montana, resources of, 15 Montana, sandstone of, 268 Montgomery Co., Penna., beginnings of quarrying, 6 Mormon Temple, stone used in, 210 Mount Eolus, section of, 107 Mount Waldo granite, 188 Napoleonite, 240 National collections, referred to, 160, 163 Nebraska, limestones of, 140 Nebraska, resources of, 15 Nebraska, sandstone of, 268 Nephrite or jade, 171 Nero Antico di Prato, 75 Nevada, marble of, 95 INDEX. 447 Nevada, porphyry of, 221 Nevada, resources of, 16 Nevada, sandstone, 268 Nevadites, 222 Newberry, Prof. J. C., on kersantite, 242 Newberry, Prof. J. C., on Yule Creek marbles, 88 Newberry, Prof. J. C., quoted, IOI New Hampshire, 16 New Hampshire gneiss, 203 New Hampshire, diorites of, 241 New Hampshire, granites of, 201 New Hampshire porphyry, 220 New Hampshire, slates of, 305 New Hampshire, soapstone in, 48 New Hampshire, syenite of, 224 New Jersey, diabase of, 232 New Jersey, granites and gneisses of, 203 New Jersey, kersantite of, 242 New Jersey, marbles of, 95 New Jersey, resources of, 16 New Jersey, sandstone of, 267 New Jersey, serpentine of, 63 New Jersey, slates of, 303 New Mexico, resources of, 16 New Mexico sandstone, 269 New Mexico, serpentine of, 64 New York, granites of, 204 New York, limestones of, 141 New York, marbles of, 96 New York, resources of, 16 New York, sandstones of, 270 New York, slates of, 304 New York, serpentine of, 64 New York, soapstone of, 49 New Brunswick, granite of, 215 New Brunswick sandstones, 288 New South Church, date of erection, 2 Nitric acid in atmosphere, 359 Norite, Keeseville, N. Y., 236 North Carolina, granite of, 205 North Carolina, limestone of, 145 North Carolina, marble of, 99 North Carolina, porphyry of, 220 North Carolina, resources of, 16 North Carolina, sandstones of, 274 North Carolina, serpentine of, 67 North Carolina, soapstone of, 49 North Dakota, resources of, 16 Nova Scotia granite, 216 Nova Scotia, trap ridges in, 230 Nova Scotia sandstones, 288 Nummulitic limestone, 154 Numidian marbles, 152 Obsidian, 172, 222 Obsidian, localities of, 223 Obsidian, uses of, 223 Ohio, limestones of, 145 Ohio, resources of, 16 Ohio, sandstones of, 274 Oil as a stone preservative, 399 Oklahoma, resources of, 16 Old Hancock House, date of erection, 2 Olivine, properties of, 27 Ontario, sandstones of, 287 Onyx, Algerian, 120 Onyx marbles or travertines, 116 Onyx marble, Arizona, 118 Onyx marble, California, 117 Onyx, Egyptian, 120 Onyx, Mexican, 119 Onyx marble, Missouri, 118 Oolitic limestone defined, 80 Oolitic limestone, Bath, England, 155 Oolitic limestone, origin of name, 80 Oolitic limestones, Kentucky, 134 Oolitic limestones, Indiana, 127 Ophicalcite, see Serpentine, 53 Ophicalcites, Italian, 74 Ophicalcites of New York, 65 Ophiolite, origin of name, 54 Oregon, resources of, 16 Oregon, sandstone of, 279 Organisms, growth of, on stones, 358 Origin of porphyry, 217 Original constituents of rocks, 18 Orton, Prof., quoted, 274 Oxidation, effects on stone, 360 Owen, J. D., quoted, 250 Page, Mr. C. G., experiments on stone, 388 Paint as a stone preservative, 399 Palisades, rocks of the, 233 Paonazza marble, 153 Paraffine as a stone preservative, 400 Parian marble, 166 Parkman House, date of erection, 2 Parmazo marble, 164 Patent hammered finish, 333 Patent or bush hammer, 348 Paving-blocks, sizes and prices of, 233 448 INDEX. Peach-bottom slate, 306 Peale, Dr. A. C., quoted, 268 Pean hammer, 348 Pegmatite, 172 Pegmatite, described, 178 Pendulum machines, 343 Pennsylvania, diabase of, 234 Pennsylvania, diorites of, 241 Pennsylvania, granites and gneisses of, 208 Pennsylvania, limestone of, 147 Pennsylvania, marble of, 100 Pennsylvania, sandstone of, 279 Pennsylvania, porphyry of, 220 Pennsylvania, resources of, 16 Pennsylvania, serpentine of, 67 Pennsylvania, slates of, 306 Pennsylvania, soapstone of, 49 Peterhead granite, 216 Pfaff, experiments of, 398 Philadelphia, first stone used in, 6 Philo Tomlinson, engaged in marble- sawing, 345 Phonolite, 227 Phonolite, localities of, in U. S., 227 Phonolites, utility of, 227 Physical agencies of rock disintegra- tion, 353 Physical and chemical properties of building-stone, 32 Pick, 349 Pinite, 167 Pink marble of North Carolina, 99 Pink marble of Georgia, 89 Pisolite defined, 80 Pitching chisel, 349 Pitchstone, 222 Pittsford, Vermont, quarries of, 109 Plain quarry-frame, 343 Planing stone, machine used, 344 Playfair, Mr., quoted, 152 Plug and feather, 349 Plug-and-feather splitting, 324, 325 Plymouth marble, composition of, 112 Point, the, 349 Pointed-face finish, 333 Polishing stone, 329 Polishing stone, preparation of sur- face, 328 Polish on marble, lasting power of, 369 Polished surface, 334 Porosity of stone, how shown, 379 Porphyritic diorites, 241 Porphyritic felsite, 218 Porphyries, porphyritic felsites, 217 Porphyry, Maine, 220 Porphyry, Massachusetts, 219 Porphyry, Minnesota, 220 Porphyry, Missouri, 22O Porphyry, Nevada, 221 Porphyry, New Hampshire, 220 Porphyry, North Carolina, 220 Porphyry, Pennsylvania, 220 Porphyry, Russian, 221 Porphyry, Sweden, 219, Porphyry, uses of, 218 Porphyry, varieties of, 218 Porphyry, Wisconsin, 220 Portage Entry sandstone, 265 Portland stone, 155 Portland (Conn.) sandstone, 258 Portland sandstone, weathering of,259 Portor marble, 165 Portugal, marbles of, 161 Position of stone in wall regarding durability, 395 Potomac marble, 93 Potstone, 45 Potsdam sandstone of New York State, 272 Potsdam sandstone, qualities of, 273 Powder, use of in quarrying, 323 Precautionary methods of laying stone, 395 Precautions to be observed in select- ing stone, 377 Preservatives for stone, 399 Prices of stone and cost of cutting, table, 422 Price-list of Italian marbles, table, 423 Protection of stone by solution, 399 Procter, Prof., quoted, 134 Proctor, Vermont, no Protogine, 178 Pumice, 222 Pumice finish, 334 Putty gloss surface, 334 Pyrite, effects of oxidation, 360 Pyroxenes, the, properties of, 24 Qualifications of good building-stone, 378 Qualities of stone as shown by tests, (tables), 403 Quarrying, time of, 383 INDEX. 449 Quarry water in stones, 364 Buarrying and splitting slate, 330 uarrying granite, 320 Quarrying marble, 321 B uarrying sandstone, 322 uartz, 172 Quartz, properties of, 20 B uartz diorite, 242 uartzite, 249 euartzite, Minnesota, 265 uartzite, South Dakota, 282 e uartz porphyry, 218 uebec, sandstones of, 288 Quincy, early quarrying at, 2 Quincy granites, 195 Quincy, Mass, quarries opened, 194 Raindrop stone, 264 Rand, T. D., quoted, 68 Ransome's process for preserving stone, 401 Ratio of absorption of building-stones, table, 404 Ratio of absorption of moisture, 385 Reade, T. Mellard, quoted, 372 Red Beach granite, 185 Red granite, Connecticut, 183 Red granite, New York, 204 Red sand-rock, thickness of formation, no Red slates of New York State, 305 Red slate in Pennsylvania, 309 Reno, Nevada, andesite used at, 243 Responsibility of architect and builder, 350 Rhode Island, granite of, 208 Rhode Island, resources of, 16 Rhodochrosite, 173 Rhodonite, 174 Rhyolites, 222 Ribbons in slate, 295 Rice, Prof. W. N., quoted, 150 Richmond granites, 211 Ricolite, 64 Rift and grain of rocks, 39 Rock classification, 42 Rock, definition of, 17 Rock-faced finish, 333 Rock-forming minerals defined, 17 Rock-forming minerals, list of, 19 Rockport, Mass., early quarries, 3 Rogers, Prof., quoted, 100 Rose-crystal marble, 96 Rosso antico of Egypt, 241 Ruin marble, 166 Russia, porphyry of, 221 Rutland, Vermont, marble quarries, 108 St. Genivieve sandstone 267 St. Anne marble, 157 Sandstone, absorptive powers of, 371 Sandstone, Alabama, 249 Sandstone, Arizona, 249 Sandstone, Arkansas, 250 Sandstone, British Columbia, 287 Sandstone, California, 251 Sandstone, Colorado, 254 Sandstone, Connecticut, 257 Sandstone, Georgia, 260 Sandstones, Idaho, 260 Sandstone, Illinois, 260 Sandstone, Indiana, 260 Sandstones, Iowa, 261 Sandstone, Kansas, 261 Sandstone, Kentucky, 261 Sandstone, Maine, 262 Sandstone, Maryland, 262 Sandstone, Massachusetts, 263 Sandstone, Michigan, 264 Sandstone, Minnesota, 265 Sandstone, Mississippi, 266 Sandstone, Missouri, 267 Sandstone, Montana, 268 Sandstone, Nebraska, 268 Sandstone, Nevada, 268 Sandstone, New Brunswick, 288 Sandstone, New Jersey, 269 Sandstone, New Mexico, 269 Sandstones, New York, 270 Sandstone, North Carolina, 274 Sandstone, Nova Scotia, 288 Sandstones, Ohio, 274 Sandstone, Oregon, 279 Sandstone, Pennsylvania, 279 Sandstone, Quebec, 288 Sandstone, Scotland, 289 Sandstone, Tennessee, 283 Sandstone, Texas, 283 Sandstone, Utah, 284 Sandstone, Virginia, 284 Sandstone, Washington, 285 Sandstone, West Virginia, 285 Sandstone, Wisconsin, 286 Sandstone and granite, relative fire- proof qualities shown, 367 Sandstones, cementing material of, 245 450 INDEX. Sandstones, color of, 247 Sandstones, composition andorigin, 245 Sandstones, definition of, 245 Sandstones, early quarrying at Port- land, Connecticut, 6 Sandstone, effects of freezing, 259 Sandstones, foreign, 287 Sandstones, geological age of, 249 Sandstone, law relative to quarrying, 7 Sandstone, lichens on, 373 Sandstone, quarrying, 322 Sandstone, tombstones of, 260 Sandstone, varieties of, 248 Sandstone, weathering, properties of, 37i Sand-blast, the, 347 Sand-blast, use of, in stone-cutting, 329 Sanders, R. H., quoted, 308 San Luis Obispo onyx, 117 Satin spar, 76 Saunders' channelling-machine, 337 Sawed face, 334 Sawing school-slates, method, 333 Sawing slate, method of, 332 Sawing stone, machines used in, 344 Schists, the, 244 Schists, origin of, 245 School-slates, manufacture of, 309 Scotland, granite of, 216 Scale of hardness, 20 Scaling house-fronts in New York, 352 Scaling of stone in lower courses, 396 Schweitzer, Dr. P., quoted, 247 Scotland, sandstone of, 289 Sculping slate, 330 Secondary constituents of rocks, 18 Selection of building-stone, 374 Selenite, see Gypsum, 75 Seneca Creek sandstone, 262 Serpentine, California, 57 Serpentine, Canada, 72 Serpentine, Connecticut, 58 Serpentine, Delaware, 60 Serpentine, England, 72 Serpentine, foreign, 72 Serpentine, Ireland, 73 Serpentine, Italy, 74 Serpentine, Maine, 60 Serpentine, Maryland, 60 Serpentine, Massachusetts, 62 Serpentine, New Jersey, 63 Serpentine, New Mexico, 64 Serpentine, New York, 64 Serpentine, North California, 67 Serpentine, Pennsylvania, 67 Serpentine. Texas, 70 Serpentine, Vermont, 70 Serpentine, composition, origin, and uses, 53 Serpentine, origin of name, 54 Serpentine, ophicalcite, verd-antique marble, 53 Serpentine, properties, 26 Serpentine, weathering qualities of, 69 Serpentine, weathering properties of, 373 Serpentine, var. Williamsite, 61 Shap granite, 216 Shell limestone defined, 82 Shell sand-rock defined, 82 Shepard, C. U., quoted, 58 Siena marble, 164 Size of cubes tested for strength, 385 Slates, 293 Slate, Arkansas, 299 Slate, California, 299 Slate, Canada, 312 Slate, Colorado, 299 Slate, Georgia, 299 Slate, Great Britain, 312 Slate, Maine, 300 Slates, Maine, distribution of, 300 Slate, Maryland, 301 Slate, Massachusetts, 301 Slate, Michigan, 302 Slate, Minnesota, 303 Slate, New Hampshire, 303 Slate, New Hampshire, 303 Slate, New Jersey, 303 Slate, New York, 304 Slate, Pennsylvania, 306 Slate, South Carolina, 309 Slate, South Dakota, 299 Slate, Tennessee, 309 Slate, Texas, 310 Slate, Vermont, 310 Slate, Virginia, 311 Slaty cleavage, cause of, 295 Slates, composition and origin, 293 Slate, early quarrying in the U. S. , 9 Slate exported to foreign countries, 10 Slate, microstructure of, 294 Slate, number necessary for a square, 298 INDEX. 451 Slate, quarrying in Vermont, date of beginning, 310 Slate, quarrying and splitting, 330 Slate waste, utilized in brick-making, 308 Slate, waste of, 297 Sledge or striking-hammer, 348 Smith's Lithology, quoted, 381 Smithsonian building, erected, 262 Smock, Prof. J. C., quoted, 141, 204 Scapstone, 45 Soapstone, Arkansas, 47 Soapstone, California, 47 Soapstone, Maine, 47 Soapstone, Maryland, 48 Soapstone, Massachusetts, 48 Soapstone, New Hampshire, 48 Soapstone, New York, 49 Soapstone, North Carolina, 49 Soapstone, Pennsylvania, 49 Soapstone, South Carolina, 50 Soapstone, Texas, 50 Soapstone, Vermont, 51 Soapstone, Virginia, 52 Soapstone, composition and uses of, 45 Soapstone, occurrence of, 47 Soapstone, weathering properties of, 373 Soft-soap-and-alum solution for pre- serving stone, 401 Solubility of cementing material of sandstone, 363 Solution, effect of, on stone, 362 Solutions for preserving stone, 399 South Carolina, granites of, 209 South Carolina, resources of, 16 South Carolina, slates of, 309 South Carolina, soapstone of, 50 South Dakota, quartzite of, 282 South Dakota, resources of, 16 Spain, marbles, 161 Specific gravity of rocks, 33 Specific gravity of stone as indicative of its strength, 390 Specific gravity of building-stones, table of, 404 Specular iron, see under Hematite, 32 Splitting stone by plug and feathers, 324 Splitting stone with wedges, invention of, 325 Splitting slate, methods of, 331 Square-drove finish, 334 Stalactite defined, Si Stalagmite defined, 81 Stalagmitic marbles of Virginia, 119 Stalagmite marble, Gibraltar, 121 Statistics of marble industry, 116 Statuary marble of Italy, 163 Steatite, soapstone, 45 Stone dressing, ancient method, 327 Stone dressing, Peruvian method, 327 Stone, induration of, 363 Stone, methods of quarrying, 314 Stone preservatives, 399 Stone preservatives, Caffal process, 400 Stone preservatives, Kuhlman's pro- cess, 402 Stone preservatives, Lewin's process, 402 Stone preservatives, oil, 399 paint, 399 paraffine, 400 " soft - soap - and- alum solution, 401 Stone preservatives, Sylvester's pro- cess, 401 Stone preservatives, Szerelmey's pro- cess, 402 Stone preservatives, Ransome's pro- cess, 401 Stone-sawing machines, 344 Stone structures, list of, 425 Stony Creek granite, 183 Stratified granite, see Gneiss, 244 Strength of building-stones, tables, 404 Strength and ratio of absorption of stone, 385 Strength of stone, preparation of cubes for tests, 386 Strength of stone, value overestimated, 385 Strength in excess of 15,000 Ibs. per sq. in. of little value, 385 Strike-joints, 316 Striking-hammer, 348 Structure of rocks, 33 Stunning stone by hammering, 397 Sulphuric acid in atmosphere, 359 Sutherland Falls, Vermont, marbles of, 109 452 INDEX. Svvanton, Vermont, marble of, 112 Sweden, porphyry of, 219 Syene, granite of, 214 Syenite, definition of, 223 Syenite, localities of, in U. S., 224 Sylvester's process for preserving stone, 401 Szerelmey's stone liquid, 402 Tables showing chemical composition of stones, 414 Tables showing qualities of stones, 400 Tables showing specific gravity of stones, 403 Tables showing strength of stones, 403 Talc, properties of, 27 Talc, see Steatite, 45 Tenant's Harbor, Me., diabase, 231 Tennessee, granite of, 209 Tennessee, limestone in, 148 Tennessee, marbles in, 102 Tennessee, resources of, 16 Tennessee, sandstone of, 283 Tennessee, slates of, 309 Testing building-stone, 384 Testing stone, Brard's process, 387 Testing stone, remarks on, 394 Texas, diorites of, 241 Texas, granite of, 210 Texas, limestone of, 148 Texas, marble of, 104 Texas, resources of, 16 Texas, sandstone of, 283 Texas, serpentine of, 70 Texas, slates of, 310 Texas, soapstone in, 50 Thulite stone, 174 Tonalite, 240 Tutten's experiments on expansion and contraction, 354 Tools used in granite-working, 328 Tooth-chiselled finish, 334 Tooth-chisel, 349 Trachyte, 226 Trachyte, definition of, 226 Trachyte, derivation of name, 227 Trachyte, localities of, in U. S., 227 Trachytes, utility of, 227 Trap, see Diabase, 228 Travertine, 116 Travertine, defined, 80 Travertine, France, 121 Travertine, Germany, 121 Travertine of Italy, 121 Travertine, origin of name, 81 Travertine, see Onyx marble, 116 Trenton limestone, weathering qual- ities of, 137 Triassic sandstone, areas of, in the U. S., 258 Trimming slate, method of, 332 Trowlesworthite, 179 Tuffs, 290 Tuff, Colorado, 292 Tuffs of the various States and Terri- tories, 292 Tuffs, foreign, where used, 292 Tuffs, Mexican, 292 Tuffs, qualities of, 291 Tuffs, uses of, 291 Tuffs, varieties of, 291 Twisted wire cord stone-saw, 346 Unakite, 212 Underthroating of sills, necessity of, 396 University Hall, Cambridge, erection of, 2 Uses of granite, 179 Uses of slate, 298 Uses of porphyry, 218 Utah, granite of, 210 Utah, marbles in, 105 Utah, resources of, 16 Utah, sandstone of, 284 Variation in stones from same quarry, 380 Varieties of granite, 128 Varieties of limestone and dolomite, 80 Varieties of liparite, 222 Varieties of porphyry, 218 Varieties of sandstone, 248 Veined stones, unequal weathering of, 382 Verd-antique marbles, poor weather- ing qualities, 382 Verd-antique marble, see Serpentine, 53 Vert de Genes, 75 Verde di Levante, 75 Verde di Prato, 75 Vermont, early marble-quarrying, 5 Vermont, granites of, 210 Vermont, marble in, 105 INDEX. 453 Vermont, resources of, 16 Vermont serpentine, 70 Vermont, soapstone in, 51 Vermont, slates of, 310 Verte Island sandstones, 287 Vinalhaven diabase, 231 Vinalhaven granite, 188 Violet, A., quoted, 158 Virginia City, Montana, andesite used at, 244 Virginia City, Nev., andesite used at, 243 Virginia, diabase of, 234 Virginia, granites of, 211 Virginia, marble of, 113 Virginia, resources of, 16 Virginia, sandstone of, 284 Virginia, slates of, 311 Virginia, soapstone in, 52 Virginia, stalagmitic deposits, 119 Viridite, see chlorite 28 Volcanic fragmental rocks, 290 Volcanic tuff, Cordelia,254 Volcanic tuff, New Mexico, 270 Wadsworth, Dr. M. E., quoted, 364 Washington Monument referred to, 352 Washington, resources of, 16 Washington, sandstone of, 285 Waverly group in Ohio, section of, 275 Wedge or plug, 349 Wedge used in stone-splitting, 349 Welsh slates, 312 Weathering defined, 352 Weathering of building-stone, 350 Weathering of limestones and dolo- mites, 367 Weathering properties of granite, 365 Weathering properties of gypsum, 373 Weathering properties of serpentine, 374 Weathering properties of sandstone, 371 Weathering properties of soapstone, 373 Weight per cubic foot of building- stones, tables, 404 Westerly granite, 208 West Rutland, Vt., description of quarries, 108 West Virginia, resources ofj 16 West Virginia, sandstone of, 285 White, Dr. C. A., quoted, 76 Wichman, Dr., quoted, 293 Williams, G. H., quoted, 62 Winchell, Prof. N. H., quoted, 137, 236, 370 Wind-blown sand, effects of, 357 Window-pane abraded by sand, 357 Winooski marble, in Wisconsin, granites of, 213 Wisconsin, limestones in, 149 Wisconsin, porphyry of, 220 Wisconsin, resources of, 16 Wisconsin, sandstone of, 286 Wyoming, granites of, 213 Wyoming, marbles of, 115 Wyoming, resources of, 16 Woodstock granite, 193 Works on building-stone, bibliogra- phy, 428 Yellow marble, Italian, 165 Yellow marble, Portugal, 162 Yellowstone National Park, obsidian in, 223 14 DAY USE RETURN TO DESK FROM WHICH BORROWED LOAN DIPT. RENEWALS ONLY TEL. NO. 642-3405 This book is due on the last date stamped below, or on the date to which renewed. Renewed books are subject to immediate recall. HEC TSECP LP D 5'69-lAM APR L 3 1999 LD21A-60m-6,'69 (J9096slO)476-A-32 General Library University of California Berkeley YC