such as that of Guernsey, for instance, which is therefore now seldom adopted. The Welsh granite has the same fault, for, with a large amount of traffic in dry weather, it becomes necessary to throw gravel over it. Guernsey macadam, broken to pass through a 2 inch mesh at the largest, is found to be by far the best material for the purpose, one coat properly applied outla ting two of any other granite. The Devon granite being coarse in grain, is used only in cubs for second-rate streets, while for pitching it is not to be compared in price or quality with that of Aberd en. Blue Bombay, and blue Port Philip granites, are hard and tough, and make good second-class roads; while grey China granite is soft and triable, and only good for the foundation of a new road.

16726 We are indebted for several of the details here given on this subject, to the article in the Dictionary of Architecture of the Architectural Publication Society. The Builder for 1866 has also entered on the merits of Scottish granites.

1673. With the architect and sculptor the name of marble is applied to all stones, harder than gypsum, that are found in large masses, and are susceptible of a good polish. On this principle, under the head of marble, are included many varieties of limestone, porphyry, and even granite and fine-grained basalts. But with mineralogists the word is used in a much more restricted sense, and is confined to such varieties of dolomite, swinestone, and compact and granularly foliated limestone as are capable of receiving a good polish.

1674. The external characters are as follows: colours white, grey, red, yellow, and green. Has generally but one colour, though it is often spotted, dotted, striped, and veined. Occurs massive, and in angulo-granular distinct concretions. Internally it alternates from shining to glistening and glimmering; lustre intermediate between pearly and vitreous. Fracture foliated, but oftentimes inclining to splintery. Fragments indeterminate, angular, and rather blunt-edged. More or less translucent. Brittle, and easily frangible. Its chemical characters are, that it generally phosphoresces when pounded, or when thrown on glowing coals. It is infusible before the blow-pipe. Dissolves with effervescence in acids. Constituent parts, Lime

Carbonic acid
Water -

56.50

43.00

0.50

100.00

1675. All the varieties may be burnt into quicklime; but it is found that in many of them the concretions exfoliate and separate during the volatilization of their carbonic acid, so that by the time that they become perfectly caustic, their cohesion is destroyed, and they fail into a kind of sand, which renders a common kiln inapplicable.

1676. The varieties of marble are almost infinite. Those employed by the ancients, as well as porphyry, are noticed in the GLOSSARY. Besides the paper On Marbles read in 1887 by Mr. Brindley, and quoted hereafter, the book by G. H. Blagrove On Marble Decoration, Sv. 1888, and that by A. Lee, Marble and Marble Workers, 8vo. 1888, are valuable contributions to the subject.

1677. The principal part of the supply to England of whitish marble is from Carrara, a small town or village of Tuscany, in Italy. The quarries at this place were celebrated from an early period, and spots are still shown about them whence they dug the marble for the Pantheon. Masses of marble are sometimes procured there nine feet in length and four to six in breadth. The quarries are the property of the principal inhabitants of

the town, who carry on an extensive trade in the article; but the difficulty of choosing the marble has induced artists to sett e there for the execution of their works, and the consequence is, that sculpture abounds and flourishes in the town. The white or Statuary, Italian-veined, Dove-coloured, Pavenazzo or purple veined, and Ravaccione (called Sicilian, supposed to have obtained its name from early shiploads of it having been reshipped or sent on from some port in Sicily, at which the vessel touched in its rovage) marbles, are but very slight variations of the same substance; the Dove and Sicilian" have a little more carbonaceous master in their composition; but they are all procured from quarries in the immediate neighbourhood of Carrara. Serravezza, in Lucca, produces Statuary, Ravaccione, veined or Bianco chiaro, Mischio di Serravezza, Bardiglio, and Bardiglio fiorito.

1677a. All varieties of Carrara marble have perishable qualities, which ought to preclude them from being ever applied to external purposes in this country. After exposure to the weather for thirty or forty years, disintegration through its entire mass, but mostly on or near the surface, evidently takes place; after the lapse of about a century, more or less, according to the quality of the marble, the entire substance fails into a kind of sparkling sand. The group of Queen Anne, &c., in front of St. Pauls Cathedral, sculptured by Francis Bird in the beginning of the last century, had been painted long since, and was in 1887 entirely renewed. A mural monument by J. Nolleke s, erected about 1780 over the centre door within the portico of Bloomsbury Church, fell on to the pavement during the winter of 1837-8, so thoroughly pulverised as to resemble a fall of snow rather than bits of marble. Milan Cathedral is built of the white marble of Monte Candoglio or Candido, on the Toce, a tributary of the Lago Maggiore, selected as better fitted to stand the atmosphere than Carrara marble, of which it is usually said to be built: the "7,000 statues" (1863) are most probably all of the latter material.

16776. The Ravaccione, or so called "Sicilian" marble, is expected to resist the action of an English atmosphere longer than Italian veined, or white Carrara marble. On exami nation, however, it will be found that its chemical and mineralogical character scarcely differs from them, except in weight, hardness, and as containing a little more carbonaceous matter. The Marble Arch, erected 1825-7 in front of Buckingham Palace, was removed to its present site 1850-1, when it was found necessary to rub the exposed surfaces with sand and stone, as they were in a state of disintegration. Perhaps the tomb by Sir F. Chantrey, executed about 1820, in the burial-ground of St. John's Wood Chapel, is the oldest specimen in London, if not in England. The surface may now be abraded with the fingers like sand. This material has of late years been extensively used in the cemeteries round London. But on a careful inspection of stones of three years' date, it will be found that the polish is nearly gone; and even the paint of the lettering has entirely disappeared. Frequent changes of temperature also tend to destroy Carrara marble more rapidly than atmospheric influer.ces; thus the mantel of a chimneypiece is invariably disintegrated long before any other part. The late C. H. Smith, in the Builder of 1864, strongly urged the employment of Hopton Wood stone (par. 1666i.) in lieu of it for all out-door works.

1677c. Massa Carrara quarries. The special produce now is-I. The ordinary marble called “Sicilian.” having a white ground variously marked with grey veins, spots, &c.: it is good for interiors as it is easily worked. II. A very hard ordinary Silician," of a bluish white with dark veins, adapted for steps and out-door work. When well polished it has great resisting power. It has been used for the principal staircase of the Merchant Venturers' school at Bristol, where the final polish was omitted; and in some "flats" in Portland Place. III. A dark grey marble with black veins, called Bardiglio, which has been largely used as a building stone in Naples, and as altar steps in Sweden. IV. A marblo called Blanc P., a bluish white without veins, but not so lustrous nor so pure a white as statuary marble. It is much used in Belgium, France, and Ireland, for statues, tombs, and floral carvings; and is little known in London. The quarry which supplied the Blanc P. is stated to have been worked out long since; but another marble so called is merely a superior class of "veined white; " a large quantity is used in London. Tyrolese marble possesses all the beauties of that obtained from the Carrara quarries, and is, moreover, from its intense hardness, almost indestructible, and better adapted for exposure to the climate of this country.

1678. There is a beautiful species of yellow marble obtained from the quarries near Siena, in Italy, and known in England as Siena marble; but the quantity now imported is not very great, and what is introduced is very poor in colour. A good quality, both in colour and vein, can, however, be procured at the quarries by special orders

1678a. The marbles of Sicily, little, if at all, employed in this country, are enumerated as follows:-Marmo di Trapani, of a grey colour; M. di Castelnuovo, of a yellow colour; M. di Segesta, of a yellow colour; M. di Taormina, of a red colour; M. di Parco, of a yellow colour; M. d' Oglastro, of a red colour; and M. di Castelaccio, of a grey colour. The two last-named marbles are readily obtainable in blocks 12 or 13 feet

long. Specimens of some, if not all of these are included in the fine collection of polished marbles made by the learned Corsi of Rome, an account of which he published; the collection was subsequently brought to England, and is believed to exist at Liverpool. Each specimen it contained is no less than 8 inches Italian long, 4 inches wide, and 2 inches thick, and highly polished on all sides.

--

1679. Many of the marbles of France and Belgium are extremely beautiful. They are chiefly used in this country for chimney pieces. The following is a list (including others) of those so worked, supplied from one of the Belgian workshops: Rouge royal; Bleu Belge; Rouge Griotte; French red; Saint Anna; Noir Belge; Noir Belge, second quality; Breccia (Béche); Breccia and black; Breccia Romana; Breccia rose; Saint Gerard Sicilian; Sicilian, white veined; Pavonazzo; Statuary; Statuary, second quality; Malachite; Ver de Mer; Black and green; Porphyry; Brocatello; Siena; Siena, second quality; Italian Griotte; Black and gold; Black and gold, second quality; Bardilla; and Sarracolin. Another marble, named Saint Mont Clarie, is a pure black.

1680. The marbles of Spain are likewise very fine, but are not exported. A specimen of the "Emperor's Red," of unusually fine quality, was presented to the Queen by the late Don Pedro, King of Portugal, for the royal mausoleum at Frogmore.

1681. The marbles of the British Islands deserve more notice from the English architect than they have hitherto received. In England there are but few as yet quarried of granular fo'iated limestone, the greater number of varieties of them belonging to the floetz or secondary limestone. The most remarkable, and perhaps most beautiful, of the English marbles, is that of Anglesea, called Mona marble, and much resembling Verd antique. Its colours are greenish black, leek green, and sometimes purple, irregularly blended with white, but they are not always seen together in the same piece The white part is limestone, the green shades are said to be owing to serpentine and ashestus. The Isle of Man marbles are--I. Black flagstone (Posidonia schist) from Poolvash, the quarries of which have been worked for upwards of two hundred years; and furnished the steps in St. Paul's Cathedral, presented by Bishop Thomas Wilson. II. Grey marble (encrinital and shelly limestone) from Poolvash, used for tables and chimney ornaments. III. Black marble (lower carboniferous) limestone, from Port St. Mary, extremely hard and durable, taking a good polish; raised in blocks and flags of great size, and used for piers, floorings, and tombstones. IV. Pale marble (carboniferous limestone (from Scarlett. Castle Rushen, nine hundred years old, and other places, are built with this most durable material. V. Spanish Head flagstone (clay schist), Port St. Mary; is a durable material, and used for lintel and gate posts; it is slightly elastic when in thin flags, and can be raised in square slabs of 16 feet. VI. Peel freestone (old red sandstone), from Craig Millin; of this stone a large portion of Peel Cathedral was built in 1226. (Cumming, Isle of Man, &c.)

1681a. The ornamental marbles of Derbyshire are mostly confined to the 1st, 2nd, and 3rd classes of limestone, which are separated from each other by the toadstone, an amygdaloidal trap rock. These marbles are usually distinguished by their colour, as white, grey, dove, blue, black, and russet; or by physical peculiarities, depending mostly on their fossil contents, as bird's-eye, dog-tooth or muscle, entrochal, shelly, and breccia marbles. Quarries of black marble are situated near Ashford, where machinery for cutting and polishing these marbles was first used in 1748. The beds of black marble seldom exceed 7 or 8 inches; it is difficult to be obtained of any considerable surface free from “shakes,” or small veins of white spar. It is also procured at Matlock and Monsaldah. A brown marble, in thin bands of various depths of colour, is called "rosewood," as it presents the appearance of it when polished. It is one of the hardest and most durable of the Derbyshire marbles. A red marble, resembling Rosso antico, is found chiefly near Newhaven, in lumps of no great size. These and other Derbyshire marbles are principally used for inlaying work, as vases, tables, &c., but chimney pieces, columns, &c., are now made at Ashford, Bakewell, Buckland Holiow, and at Derby. This Florentine work, as it is called, is remarkable for fineness of execution and beauty of design, and is almost confined to the county.

16816. A beautiful greyish-black coralloid marble is also found in Derbyshire and in Wales. The corals it contains are of the porous kind, of the most elegant species, lodged at all angles and in all directions, and are in general about one inch and a half long and three quarters of an inch broad. The other species of coralloid marble is equally beautiful and compact, fine, even texture, very hard, of a deep jet black, and capable of a very high polish. It is variegated with species similar to the above, but smaller, and of a less elegant texture; among these it has usually a great number of sea shells, both turbinated and bivalve, the coral and shells being of a pure snow white.

There are
Some

1681c. The North Devonshire marbles are abundart and diversified. varieties of black and white, from Bridestow, South Tawton, and Drewsteignton. of the Chudley, Staverton, and Berry Pomeroy, marbles, have a black ground with large veins of calcareous spar traversing it in all directions. The variegated marbles are gene

rally reddish, brownish, and greyish, variously veined with white and yellow, and the colours are often intimately blended. The South Devonshire marbles, now chiefly worked at St. Mary Church, Torquay, from the Babbacombe limestone, are called after the name of the estate or quarry from whence they are taken, such as the Petiton, Ogwell, Ashburton, Babbacombe, &c. The colours are red, grey, and variegated, of almost every tint. The sizes of the blocks vary from 1 to 10 tons; the ordinary length runs from 4 to 5 feet; 7 to 8 feet is considered as a good length. At Ipplepen are reddish varieties that are extremely handsome. They are of different qualities, as compact, porcellanic, granular, crystalline, shelly, magnesian, pozolanic or water, stinking or swine. The Bartons quarry at Ipplepen, belonging to Mr. Field, of Parliament Street, is worked at 80 to 100 feet in depth; the lowest beds are about 8 feet thick, and of a mottled character, being dark red and white in colour; the deposit over it is streaky and lighter in colour. Blocks of 18 feet square are now conveyed to London. This quarry has lately supplied the monolithic polished shafts for the forty columns (18 out of one block), each 12 feet 3 inches in length, and 18 inches diameter on the fillet, with many others, for the new building of the National Provincial Bank of England, in Bishopsgate Street. The bases are of Irish black marble, and the caps of the cream-coloured Huddlestone stone. In the corridor of the new Freemasons' Hall are four columns, two being from the Bartons quarries, and two of Languedoc marble: eight others are placed in the coffee-room of the Charing Cross Hotel. The limestones of Plymouth are not so fine. They are of two sorts; one, an ash colour shaded with black veins; the other blackish grey and white, shaded in concentric spots interspersed with irregular red spots; or black with white veins about a quarter to an inch in width.

1681d. Serpentine, "beyond all question, the most beautiful of the ornamental stones of this country" (Hunt). is chiefly found in the sea-bound peninsula called the Lizard, the most southerly land in Great Britain. This rock, with another ca led diallage, constitute nearly half of the Lizard peninsula Serpentine has evidently been under the influence of heat. At one spot it seems to shade off into the hornblende slate in which it is embedded; at another, it has every appearance of having been thrust up among the hornblende slate. Sir Henry de la Beche wrote, many years since, that serpentine ought to be employed for decorative purposes. He named Landewednack, Cadgwith, Kennack, Cove, and Goosehilly Downs, as four sites whence beautiful specimens might be obtained, varying in colour, as, an olive green base striped with greenish-blue steatite veins; another specimen, very hard, with a reddish base studded with crystals of the mineral called diallage, which when cut through and polished, gives forth a beautiful metallic green glitter, heightened still further by the reddish tint of the mass in which it is embedded. To the Exhibition of 1851, Penzance sent fine specimens in all kinds of ornaments. The blocks are small, but sometimes they have been obtained 7 feet in length and 4 or 5 tons in weight; the largest was 8 feet long, 3 feet wide, and 24 feet thick; from 2 to 3 feet long is the usual size. The best blocks are worth from 5 to 10 guineas per ton, according to their weight, the larger the size the higher is the value in an increasing proportion. Chemically, steatite and serpentine differ little from each other, and as they are quarried in juxtaposition, specimens of both kinds are selected for use; but serpentine being much harder and more richly coloured, is appropriated to the larger articles.

168 le. In the Builder of 1865, p. 877, it is stated that serpentine is not a marble, but a tale containing a tolerable quantity of chromate of iron. It is sometimes good for external ornamentation, but never when it has the white streaks so commonly seen in it. Hunt's Handbook to the 1851 Exhibition, gives the following analysis of serpentine obtained at the Lizard: ---Magnesia, 38 68; silica, 42-50; lime and alumina, 2·10; oxide of iron, 1 50、 oxide of manganese, 10; oxide of chromium, 0:30; the colouring matter is probably a combination of chromium, iron, and manganese. In his Handbook to the 1862 Exhibition, it is called a hydrated silicitate of magnesia, composed of silica, 43'64; magnesia, 43-35; and water, 1301 = 100. Besides the supply from the Lizard, it is obtained in Anglesea, Portsoy in Banffshire, Unst and Fetiar in Scotland. The " green marble," or serpentine, of Connemara, is noticed among the Irish marbles. This material is sawn by steam power

with sand and water; and when brought into the form required, it is ground, turned, rubbed. and polished until it presents a beautiful glossy surface, said to be capable of resisting grease and acids, which is not the case with marble in general.

1681f. It is said that two brackets of old monuments in Westminster Abbey; the panelbordering of the monument erected to the memory of Addison; the brackets of a chimneypiece at Hampton Court, are all carved in serpentine, and the present condition of these specimens shows the durability of it. Equal to granite in durability," is the statement made in advertisements, but probably some further time must elapse before such a statement can be endorsed, though it may be allowed that it appears to stand atmospheric influences remarkably well. Experiments on the strength of serpentine have been noticed in par. 1502g. Therein is mentioned a shaft of Poltesco grey-green Devonshire serpentine, one of the weakest examples, which went across and not with the vein: the latter running

In the line of the diameter. The green serpentine has been used lately on the outside of some offices in Cornhill; and the red quality in 1853 in Leicester Square

1681g. Purbeck, Petworth, or Sussex marble, is the name of a material common to Derbyshire, Dorsetshire, the Isle of Wight, Kent, Surrey, and Sussex. It is found at Dinton, near Aylesbury, and it occurs at Boulogne and at Beauvais, in France. In some places, as in the most westerly quarries near Corfe Castle, and at the top of the Isle of Portland, the Purbeck stone is so highly coloured and fine-grained, that it is chiefly identified as beionging to the fresh water deposits by the fossils it contains. In general, the stone may be said to be fine grained in the quarries north and west; while in those approaching the east the pattern is larger, the shells well defined, and scarcely any of them broken; the marble from this district is therefore handsomer, and more in request for ornamental purposes. Purbeck was well known for its quarries during the middle ages, when the marble was in great request for decorating the clustered shafts and sepulchral tombs, and for pavements, in churches. At the present time, there is scarcely sufficient demand to keep more than a few men at work, and this at Woody-hyde, near Corfe Castle, where the genuine material or Purbeck marble can be obtained, and that quarry is a hole more than a quarry. It has been stated that, during the middle ages, this material was also obtained from quarries at Parham Park, six miles north-east of Arundel, but there are now no traces of it left on the surface.

1681h. All varieties of Purbeck marble contain a large proportion of clay in their com position, which is one chief cause of their perishable nature. In the interior of buildings the moisture in the air will be condensed, and absorbed into the argillaceous portion of the marble. While this process is going on, the lustre of the polish is gradually diminished, the colour is altered, its hardness and cohesion destroyed, until the surface is completely changed to a dull earthy appearance, and decay results, which will be facilitated in proportion to the amount of clay contained in a given mass. When, as in sinal! columns, this material is placed with the planes of lamination in a vertical position, there results another and a greater tendency to decay. The clustered columns in the Temple church, though renewed in 1840-42, had already lost much of their polish in 1853, a preliminary stage towards decay. The large ancient columns supporting the clere-story at Westminster Abbey, have now scarcely a trace left of their original surface. (C. H. Smith, Transactions, Institute of British Architects, 1853). As already stated this sort of marble is obtained in Kent, where it is also known as Bethersden marble, and likewise as Lovelace marble, obtained near Ashford In the east and west sides of the new quadrangle of St. John's College, Oxford, are sixteen entire columns of " Bletchingden marble," which were put up in 1631-35. It may be seen in Hythe Church and in some of the neighbouring churches, where it is often varnished in lieu of being polished. The Purbeck marble columns used in Lincoln Minster, in 1186-1200 are asserted to have been worked up by vinegar.

1682 Of the Scotch marbles the principal are the Tier, of which there are two varieties, red and white. The Iona, whose colours are a greyish white and snow white, sometime▪ intermixed with steatite, giving it a green or yellow colour in spots and known under the name of lona or Icolmkill pebbles. It does not take a high poli-h The Skye marble, of greyish hue, with occasionally various veins. The Assynt varieties of white, of grey, and dove colour. Glen Tilt marble, white and grey, with occasionally yellow and green spots. Marble of Balliculish, of a grey or white colour, and capable of being produced in considerable blocks. Boyne marble, grey or white, and taking a good polish. Blairgowrie, in Perthshire, of a pure white colour, fit. it is said, to be employed in statuary and for architectural purposes; and Glenavon, a white marble, said by Wiliams (Natural History of the Mineral Kingdom) to be a valuable marble, is not used, from the remoteness of its situation and the difficulty of access to it.

1683. Ireland is rich in marbles. The dark colours vary from jet black to dark dove colour, purple, blue, and grey; the light colours, from the pure snow white to the celined, cream coloured pink, and light grey. The variegated consist of the serpentine, black and white veined, mottled, and those marked with fossil organie remains. The black marbles, which are those of most value in Ireland, are extensively met with, and belong to the lower limestone. The merchantable beds of the best quality, which have been extensively worked, are met with in the counties of Galway, Limerick, Carlow, and Kilkenny. It is also found in the counties of Mayo and Waterford. The best quarries are considered to be those close to the town of Galway, near the bank of Lough Corrib. It occurs in three beds, varying from about 9 to 12 inches in thickness. One is called the "London bed,” as it supplies most of the black marble exported to London. Blocks are raised of an average size of about 5 to 10 feet in length, and 4 to 5 feet in width; others 20 feet in length can be obtained. Some blocks 16 feet in length were sent over for a staircase for the Duke of Hamilton's seat in Scotland, who was also furnished with landings and so.id balustrades worked to a fine polish. Angliham and Merlin Park quarries supply black marble of the very finest description, receiving a high polish. Steps of it were supplied for the porticos at St. Paul's, the staircases at Marlborough House, Hampton Court, and Kensington Palace, under Sir C. Wren, cir. 1700. At Oughterard, the beds contain more