or less silica, rendering them not so valuable. At Kilkenny, it abounds with shells, which become more conspicuous as the marble dries Kilkenny marble was once extensively employed in Ireland, but the black is now preferred. The polish of black marble, while it is considerably affected by dampness, is much improved and preserved by being kept dry. 1683a. Dark grey and dark mottled grey marbles are met with chiefly in King's county and in several parts of the county of Cork. Near Tullamore, marble is obtained in large blocks capable of receiving a fine polish, and is much used for chimney-pieces and ornamental works. The limestone around Cork produces easy working marble of a light grey or dove colour, and more or less mottled, receiving a good polish. In the primary districts of Donegal, a light grey and bluish grey coloured marble of close grain is found to a great extent; most of it, however, is hard to work from the quantity of silex it contains. The same kind of a bluish tint is very frequent in Connemara. It is compact in texture, but does not always produce a satisfactory polish. White marble occurs in the western portion of county Donegal, differing much from that of Connemara. It is of comparatively casy conversion, and can be obtained in cubical blocks in great quantities; its very coarsely granular texture, however, is prejudicial to it for many purposes; for boldly executed works in sculpture, where the expense of carriage would be avoided, it might be advantageously employed for many purposes; but it will not vie with the marble of Carrara. The Connemara white marble is hard and fine, and the strongest yet found; it cannot, however, be procured in large blocks free from streaks, which pass through the blocks parallel with the beds. At Chevy, near Dungannon, county Tyrone, a very delicate cream coloured marble is obtained, very compact in texture, receiving a high degree of polish, and blocks of great length can be procured. The coarsely crystalline and fossiliferous limestone at Ardbraccan produces light coloured marble of easy conversion.

16836. Of the variegated marbles, the Siena of the best quality is perhaps the most beautiful. It is obtained in several places in King's county; but the best, the veined or mottled Siena, is found near the Seven Churches. It is susceptible of a high polish, and exhibits many bright and distinct colours. Marble of the same character also prevails, having a dove coloured ground, varied or mottled with Siena colour. In the county of Armagh, a Siena, or rather a brownish red marble, is found, c. ntaining a great number of fossil shells; several varieties of colour, from a very light reddish brown to a rather dark red, are also met with, more or less marked with shells. At Pallaskenry in the county of Limerick, a dark red and mottled marble is abundant, and has been much used. coloured marble, of a compact but slaty texture, occurs in the county of Cork, extending from the city in a narrow seam, for a distance of several miles. It is hard to work and dull in colour at one time it was extensively used.

A red

1683c. The serpentine, or green marble, as it is usually called, of Connemara, in county Galway, is of a dull green colour. Blocks are raised of considerable size, from which slabs can be obtained, at Barnanoraun quarry, near that at Recess; and at Letternaphy quarry, near Clifden; the latter being rather coarse in quality; while at Tievebaun quarry, near Recess, the marble is dark green, very sound, and free from shakes of any kind. Black and white marble, and that of a mottled character, occur near Cork, in the counties of Waterford, Longford, and Kerry; some of the varieties are very fine; that obtained near Mitchelstown is well marked and receives a high polish. The limestone obtained near the Seven Churches in King's county, when polished, produces a good marble of an even grey colour. It is strongly mottled with very numerous fossil organic remains. It is easily worked, and raised from the quarries in thin beds. This marble, in a polished state, has been used in the construction of one of the principal ruins at the Seven Churches; some of the stones retain their polish to this time, while others exhibit decay. (Wilkinson, Geology, &c. of Ireland, 1845). A fine purple marble is found at Loughlougner in county Tipperary, which is said to be beautiful when polished. Some of a purple colour, and purple and white intermixed with yellow spots, were to be procured in the islands near Dunkerron in the river Kenmare.

Its tenacity is stated at 6,000 lbs per square inch, and its crushing weight is also put at

6,000 lbs. per square inch. (Hant.) (1520q )

SECT. IV.

TIMBER.

1684. The information we propose here to lay before the reader relative to the different species of timber is extracted from Miller's Gardener's Dictionary, Rondelet's Art de Bàtir, Rees's Cyclopædia, and Hunter's edition of Evelyn's Sylva. To give any thing like the information that would satisfy the botanist would be out of place in an architectural work; and we therefore confine our observations to those which will be useful to the student.

1685. OAK. Of this most valuable timber for building purposes Vitruvius (lib. ii. cap. ix.) enumerates five species, which it would now be difficult to identify. That some species of the Quercus of the botanists are more valuable for building purposes than others no doubts exist. Evelyn seems to commend especially the Irish oak, because of its withstanding the efforts of the worm; but it is not easy to ascertain the particular species to which he alludes In the present day the Sussex oak is esteemed the most valuable; a value, according to some authors, derived from the nature of the soil and from good management in the culture, which is an object of no small importance.

1686. Generally, it has been usual to consider England as producing, without difference in quality, but one species of oak; but two sorts are well known to the English botanist, the Quercus Robur and the Quercus Sessiliflora. The former is found throughout the temperate parts of Europe, and is that most common in the southern parts of England. Its leaves are formed with i regular sinuositis, and their footstalks are short, occasionally almost without any at all. It attains a very large size and the wood is tolerably straightgrained and pretty free from knots, in many instances resembling the German species called wainscot. It is easily split for making laths for plasterers and slaters, and is beyond doubt the best sort for joist, rafters, and other purposes where stiff and straight-grained timber is a desideratum. In the Quercus Sessiliflora, which, though found about Dulwich and Norwood, according to Miller, appears to be the common oak of Durham, and perhaps of the north of England, the leaves have long footstalks, frequently an inch in length, and their sinuosities are not so deep, but are more regular than those of the Robur just described. The acorns are so close to the branches as to have scarcely any stalks. The wood is of a darker hue, and the grain is so smooth that it resembles chesnut. Than the Robur it possesses more elasticity, hardness, and weight, but in seasoning it is subject to warp and split; hence unfit for laths, which in the north of England are rarely of oak. There is no reason for supposing, as has been conjectured, that the oak of the Gothic roofs of the country is of this species, though we are aware of the great durability of the oak in the buildings in the northern part of the island.

1687. The specific gravity of the species first named, that is, the Quercus Robur, may De taken at about 800, and the weight of a cube foot 50·45 lbs. That of the last-named at 875, and the weight of a cube foot at about 5500 lbs. Their cohesive force and toughness are proportionable.

1688. The American species scarcely claim a notice here, because their use in England is, from every circumstance, out of the question. Of the red oak of Canada (Quercus rubra), the only one of which the use could be contemplated, we merely observe, that it is a light, spongy, and far from durable wood, though, in the country, in many instances useful. Its growth is rapid, and it rises to the height of 90 or 100 feet.

1689. There is a species of oak imported from Norway, which has received the name of clapboard, and another imported from Holland, known under the name of Dutch wainscot, though grown in Germany, whence it is floated down the Rhine for exportation. The latter is destitute of the white streaks which cross the former, and is thereby distinguished from it. The use of these woods has latterly much diminished in England. They are both softer than common oak, and the clapboard far inferior to wainscot. They are more commonly used for fittings and fixtures, whereto they are well adapted. In damp situations, oak decays gradually from its external surface to the centre of the tree; the ring on the outside, which it acquired in the last year of the growth of the tree, decaying first; but if the tree be not felled till past its prime, its decay is reversed by its commencement at the centre. An oak rarely reaches its prime under the age of an hundred years; after that period, which is that of its greatest strength, it cannot be considered as fit for building purposes; and, indeed, it may be taken as a rule, that oak before arriving at its maturity is stronger than that which has passed it.

1690. If the architect has the opportunity of selecting the timber whilst in a state of growth, he will, of course, choose healthy, vigorous, and flourishing trees. Those in which the trunks are most even are to be preferred. A mark of decay is detected in any swelling above the general surface of the wood. Dead branches, especially at the top of the tree, render it suspicious, though the root is the best index to its soundness. eThe notion of Alberti (De Re Edificatoria), of using all the timber in the same building now

the same forest, is a little too fanciful for these days, though we confess we have some misgivings in impugning an authority which, in most other respects, we are inclined to receive with the highest veneration.

1691. In felling not only the oak, but all other large trees, the great branches should be Srst cut off, so that the tree may not be injured or strained in its fall; and the trunk, moreover, must be sawed as close to the ground as possible. When felled, but not before, it is to be barked, trimmed of its branches, and left to season. Before, however, leaving it for this purpose, it is considered by workmen better to square it, which, it is thought, prevents its tendency to split. If to be employed for posts or bearing pieces, boring it has been employed with success; but it is needless to observe, that in pieces subject to transverse strains such a practice is not to be recommended.

1692 The pieces selected for building must be chosen with the straightest grain; but there are pieces which are occasionally employed, as for knees and braces, wherein a curvilinear direction of the fibres of the timber is extremely desirable. It may, however, be generally stated, that, in the case of two equal-sized and seasoned pieces, the heavier is the piece to be preferred.

1693. In oak, as in all other woods, the boughs and branches are never so good as the body of the tree; the great are stronger than the small limbs, and the wood of the heart stronger than all. When green, wood is not so strong as when thoroughly dry, which it rarely is till two or three years after it is felled. It is scarcely necessary to say, that, containing much sap, it is not only weaker, but decays sooner. It is weakened by knots, at which, in practice, it is found that fractures most frequently occur; and it is important to the architect to recollect that he should always reject cross-grained pieces.

1694. The great use of oak in this country is more for ship-building purposes than for architectural, its use, except in the provinces, being principally confined to pieces which are much liable to compression, or where great stiffness is required, or in pieces like sills to windows and door-cases, where there is much alternation of dryness and damp. So early as 1788, the consumption of oak for ship-building purposes was, in that year upwards of 50,000 loads.

1695. When of good quality, it is more durable than any other wood which is procurable of a like size. In a dry state, it is ascertained to have lasted nearly a thousand years. The open-fibred porous oak of Lincolnshire, and some other places, is a bad sort. The best is that with the closest grain and the smallest pores. The colour, as is well known, is a fine brown; that which partakes of a reddish hue is not so good as the other. smell of it is peculiar; it contains gallic acid, and it assumes a black purple colour when damp, by contact with iron. It warps and twists much in seasoning, and shrinks in width about one thirty-seventh part.

The

1696 CHESTNUT. One of the finest of the European timber trees, the Fagus castanea of botanists, was heretofore so common in this country, that Fitzstephen, in his description of London about the time of Henry II., mentions a fine forest of chesnuts as growing on the northern side of the city. It is stated to have been used in the buildings of our incestors, but it is very doubtful if it was so employed. The young tree vies with the oak in durability, from the small proportion of sapwood it contains. Of its durability, the roofs of Westminster Hall, that of King's College, Cambridge, and that of Notre Dame, at Paris. are cited as examples, though the fact of the latter being of chesnut is doubted by Rondelet, who says that Buffon and D'Aubenton thought it a species of oak, which is now well known to be the case in the roof first named.

1697. Chestnut, however, is not to be trusted like oak. As Evelyn observed, it is often well-looking outside, when decayed and rotten within. Belidor says it soon rots when the ends of timbers of it are closed round in a wall.

1698. It is, perhaps, from the circumstance of its colour so nearly resembling that of oak, that one timber has so often been mistaken for the other. The difference, however, is, that the pores of the sapwood of the oak are larger and more thickly set and easily distinguished, whilst those in the chesnut require magnifying powers to be distinguished. But a more decided difference is, that the chesnut has no large transverse septa. It is far easier to work than oak, and is not very susceptible of swelling and shrinkage. From what has been mentioned above, it may be inferred that the wood, though tough and com pact, is, when young, hardest and most flexible, the old wood being often shaky and brittle. 1699. Water pipes of this tree endure much longer than those of elm; and for tubs and vessels to hold water, it is superior to oak; for when once thoroughly seasoned, it will neither shrink nor swell, on which account it is used by the Italians for wine tuns and casks. It will thrive on most soils, but rather delights in a rich loamy land, succeeding well. also, on that which is gravelly, clayey, or sandy. Mixed soils are suitable to it, and it is found in the warmer mountainous situations of most parts of Europe.

1700. From the experiments, the cohesive force of a square inch of chesnut, when dry varies from 9570 to 12,000 lbs., and the weight of a cubic foot, when dry, is from 48 to 55 lbs.

1701. BEECH (Fagus Sylvatica). A beautiful tree, growing to a considerable height, and carrying a proportionable trunk. It flourishes most in a dry warm soil, and grows moderately quick. The wood is hard, close, has a dry even grain, and, like the elm, bears the drift of spikes. The sorts of beech are the brown or black, and the white beech. It is common throughout Europe. In the southern parts of Buckinghamshire, where the soil is chalky, it is particularly abundant; and such is the case near Warbleton. in Sussex, on the southern range of chalk hills, where the beeches are very fine.

1702. Constantly immersed in water, the beech is very durable; such also is the case with it when constantly dry; but mere damp is injurious to it, and it is very liable to injury by worms, though to these Duhamel considers it much less liable when water-seasoned, than when seasoned in the common way. To render it less liable to the worm, it has been recommended to fell it about a fortnight after Midsummer, to cut it immediately inta planks, which are to be placed in water about ten days and then dried. Beech is little use i in building, except for piles, in which situation, if constantly wet, they are very durab'2. From its uniform texture and hardness, it is a good material for tools and furniture, and of it, in boards and planks, large quantities are brought to London. It is without sensible taste and smell, easy to work, and susceptible of a very smooth surface. The white sort is the hardest, though the black is tougher, and, according to Evelyn, more durable. The weight of a cube foot varies from 43 to 53 pounds.

1703. WALNUT (Juglans, quasi Jovis glans) is of several sorts. The Juglans Regia, or common walnut, was formerly much cultivated in this island, as well for the sake of its timber as of its fruit. On the former account the importation of mahogany has long since rendered its cultivation less common. It flourishes better in a thin limestone soil, than in one that is rich and deep, and, if raised for timber, should not be transplanted, but remain in the place where it is sown. For furniture, from its rich brown colour, it is by many persons preferred to mahogany. Its scarcity renders its employment rare for building purposes, though by the ancients it was so employed. One of its properties is, that it is less liable to be affected by worms than any other timber, cedar only excepted; but from its brittle and crossoss-grained texture, it is not generally useful for the main timbers of a building.

1704. The heart-wood is of a greyish brown with dark brown pores, often veined with darker shades of the same colour, which are much heightened by oiling. The texture is not so uniform as that of mahogany, nor does it work so easily, but it may be brought to a smoother surface. The weight of a cubic foot is about 45 pounds.

Its

1705. CEDAR (Pinus Cedrus) is an evergreen cone-bearing tree, of which though several have been grown in this country, it is too scarce to be employed in building. durability is very great; such, indeed, that Pliny states cedar to have been found in the Temple of Apollo at Utica, which must have been 1200 years old. Its colour is a ligh rich yellow brown, with the annual rings distinct. It is resinous, and has a powerfu smell. The taste is slightly bitter, and it is not subject to worms. It is very straight in the grain, works easily and splits readily. Weight of a cubic foot from 30 to 38 pounds. 1706. FIR (Pinus Sylvestris). The red or yellow fir is produced on the hills of Scot land; but the forests of Russia, Denmark, Norway, Lapland, and Sweden produce the finest timber of this species. It is imported, under the name of red wood, in logs and deals From Norway the trees are never more than 18 inches diameter, whence there is much sap wood in them; but the heart is a stronger and more durable wood than is had from large trees of other countries. From Riga a great deal of timber is received under the nam of masts and spars: the former are usually 70 or 80 feet in length, and from 18 to 25 inche diameter; when of less diameter they take the latter name. Yellow deals and planks ar imported from Stockholm, Frederickshall, Christiana, and various other parts of Swede Russia, Norway, and Prussia. Of the pine species the red or yellow fir is the most durable and it was said by the celebrated Brindley, that red Riga deal, or pine wood, would endur as long as oak in all situations. In Pontey's Forest Pruner, on the authority of Dr. Smit an instance is given of the durability of natural-grown Scotch fir. It is therein state that some was known to have been 300 years in the roof of an old castle, and that it w as fresh and full of sap as timber newly imported from Memel, and that part of it actually wrought up into new furniture. It is to be observed, that foreign timber h an advantage too seldom allowed to that which is grown at home, the former being alwa in some degree seasoned before it arrives in this country, and therefore never used in unseasoned a state as is usually the latter timber.

W

1707. From its great lightness and stiffness it is superior to any other material for bean girders, joists, rafters, and framing in general. In naval architecture it is used for ma and various other parts of vessels. In joinery, both internal and external, it stands bett is nearly as durable as oak, and is much cheaper.

1708. There is great variety in the colours of the different sorts of this fir: it is genera of a red or honey yellow of different degrees of brightness, and consists in section of Laa and soft circles alternately, one part of cach annual ring being soft and light coloureci,

other harder and dark coloured, and possessing a strong resinous taste and smeli.

When

not abounding in resin it works easily. That from abroad shrinks in the log, from seasoning, about one thirtieth part of its width.

1709. The annual rings of the best sort of this timber do not exceed one tenth of an inch in thickness, their dark parts are of a bright red colour. That from Norway is the finest of the sort, to which the best Riga and Memel are much inferior. The inferior timber of this kind, which is not so durable nor so capable of bearing strains, has thick annual rings, and abounds with a soft resinous matter, which is clammy and chokes the saw. Much of the timber of this sort is from Sweden, but it is inferior in strength and stiffness. which is produced in the colder climates is superior to that which is the product of warmer countries, the Norway timber being much harder than that of Riga. The weight of a cubic foot of this fir, when seasoned, varies from 29 to 40 pounds. That of English growth, seasoned, from 28 to 33.

That

1710. WHITE FIR (Pinus abies), commonly called the spruce of Norway, whose forests produce it in abundance. This is the sort which in deals and planks is imported from Christiana, in which condition it is more esteemed than any other sort. The trees from which these are generally obtained are of 70 or 80 years' growth, and are usually cut into three lengths of about 12 feet each, which are sawn into deals and planks, each length yielding three deals or planks. Their most usual thickness is 3 inches, and they are generally 9 inches wide. In this country they are sold by the hundred, which in the case

of white as well as yellow deals, contains 120 deals, be their thickness what it may, reduced to a standard one of an inch and a half, a width of 11 inches, and a length of 12 feet. What is called whole deal is an inch and a quarter thick, and slit deal is one half of that thickness. It unites better by means of glue than the yellow sort, is used much for interior work in joinery, and is very durable when in a dry state.

1711. The colour of the spruce fir is a yellow or rather brown white, the annual ring consisting of two parts, one hard, the other softer. The knots are tough, but it is not difficult to work. Besides the importation above named, there is a considerable quantity received from America. Of the Christiana fir a cubic foot weighs from 28 to $2 pounds when seasoned. That from America about 29 pounds; and the Norway spruce grown in Britain about 34 pounds. In seasoning it shrinks about a seventieth part, and after being purchased as dry deals at the timber yards, about one ninetieth.

1712. AMERICAN PINES. The Pinus Strobus, or what is called the Weymouth or white pine, is a native of North America, imported in logs often more than 2 feet square and upwards of 30 feet in length. It is an useful timber, light and soft, stands the weather tolerably well, and is much used for masts. For joiners' work it is useful from its clean straight grain. But it should not be used for large timbers, inasmuch as it is not durable, and is moreover very susceptible of the dry rot. Its colour is a brown yellow, and it has a peculiar odour. The texture is very uniform, more so, indeed, than any other of the pine species, and the annual rings are not very distinct. It stands well enough when well seasoned. A cubic foot of it weighs about 29 pounds.

1713. The yellow pine, or Pinus variabilis, is imported into England, but it is not much used; it is the produce of the pine forests from New England to Georgia.

1714. The pitch pine (resinosa), remarkable for the quantity and fragrance of the resin it produces, is a native of Canada. It is brittle when dry, and, though heavy, not durable. It is of a much redder hue than the Scotch pine, and from its glutinous property difficult to plane. The weight of a cubic foot is 41 pounds.

1715. The silver pine (picea) is common in the British plantations. This species of timber is produced in abundance, and is much used on the Continent both for carpentry and ship-building. It is light and stiff, and according to Wiebekin, lasts longer in air than in water. A cubic foot weighs about 26 pounds.

1716. The Chester pine (pinaster) is occasionally cultivated in the British pla..tations. It is better suited to water than exposure to the air, and has a finer grain, but contains less resin, than the pine or silver fir. A cubic foot weighs about 26 pounds.

1717. LARCH (Pinus Larix). A timber tree only lately to any considerable extent adopted in the plantations of Great Britain, among whose cultivators the Duke of Athol has been one of the most ardent and successful. It grows straight and rapidly, is said to be durable in all situations, and appears to have been known and appreciated by Vitruvius, who regretted the difficulty of its transport to Rome, where, however, it was occasionally used. Wiebekin prefers it to the pine, pinaster, and fir, for the arches of timber bridges. To flooring boards and stairs, where there is much wear, it is well suited, and when oiled assumes a beautiful colour, such, indeed, that when used for internal joinery, a coat of varnish gives it a more beautiful appearance than it could receive from any painting. The American larches do not produce turpentine; but the timber has been considered equal to the European sorts. It is of a honey yellow colour, and more difficult to work than the It bears the driving Riga or Memel timber, though, when obtained, the surface is better.

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