Modern science, however, has discovered many other ways of seasoning timber than these. The processes of Sir W. Burnett, Ryan, and others, are now generally resorted to for this purpose ; and are found effective to a certain extent, if not quite realizing all their advocates claim for them.
In ash, there is little difference in the quality through the whole thickness of the tree, the outside is rather the toughest: it soon rots when exposed to the weather, but will last long when protected.
Of elm, some sorts will decay sooner than the brown or red. It is improper for roofs or floors, being generally cross grained, and very liable to warp ; it also shrinks very con siderably, not only in breadth, but lengthwise ; but it answers well when used under water; is not liable to split ; and bears the driving of bolts and nails better than any other timber.
Beech is hard and close. There is a black or brown, and white kind : the brown is tough, and sometimes used as a substitute for ash ; it is improper for beams, because a small degree of dampness in the walls very soon rots the ends; it is most suitable for furniture, or for works constantly under water.
Poplar, though of a very close quality, is liable to the same objections as the beech in beams, but is well adapted for floors and stairs, being not easily ignited: however, it rots soon when exposed to the weather.
Ash resembles the poplar in appearance; is soft and tough; lasts when exposed to the weather ; and is equally good through the bisly of the tree. The sycamore and lime are subject to the same objections, in roofing and flooring tim bers, as the poplar and beech. The lime is something like the ash in quality, and, like it, is greasy when worked smooth : it is suitable for furniture.
Birch is equal in quality quite across the body of the tree; is very tough, but does not last when exposed to the weather ; it is also subject to be destroyed by worms.
Chesnut, viz., the sweet, or Spanish, not the horse-clies. nut.) is frequently found in old buildings in England: and although difficult to be distinguished front oak, differs from it in this respect, wherever a nail or bolt has been driven into oak before it was dry, a black substance appeals round the iron, which is not the case ire Chesnut.
The walnut-tree is now, in this country, too valuable to be used in the f•amings of roofs or floors; and in furniture it has long been superseded by mahogany ; it is used chiefly in stocks of firelocks, fbwling-pieces, pistols, &c.
Mahogany is used chiefly in furniture, and also sometimes in doors and window-sashes ; it is sawn out and seasoned by perching out in the winter, and drying in the open air ; the use of fire is not advisable. This beautiful timber was intro duced into England about the beginning of the last century : its first application was ill a box for holding candles, made by a Mr. Wollaston for a Dr. Gibbons, who had afterwards
a bureau of it ; the Duchess of Buckingham had the second bureau. It very soon came into general use. It is divided chiefly into Jamaica and Honduras ; the former is by much the hardest and most beautiful ; they may be readily distin guished before they are oiled ; the pores of the Honduras appear quite dark, those of the Jamaica as if filled with chalk. See MAHOGANY.
Fir, being cheaper, and more easily wrought than oak, and next to it in usefulness, is more used in Britain than any other kind of timber. That most generally employed in carpentry is distinguished by the name of Memel, (which includes Dantzie and Riga :) Norway, (which also includes Swedish,) is much used for the smaller timbers, and answers well either when exposed to the air, or under ground. Dranton, or Dram, is suitable for flooring. All these are very durable. American hr is much softer, but suits inside joinery work, such as panels and mouldings. What is termed in England white deal, and in Scotland pine-wood, that is, fir deprived of its resinous part, being very durable when kept dry, is much used by cabinet-makers ; but, as it will not stand the weather, it is little used ill carpentry or joinery.
Evelyn makes the following observation on the use of fir :—• That which comes from Bergen, Swinsund, Mutt, Longland, Dranton, (called Dram,) long, straight, and clear, of a yellow and more cedary colour, is esteemed much before the white for flooring and wainscot; for masts, those of Prussia, which we call spruce. and Norway, especially from and about 1Zia. are the best." The' trirtaits, as Vitruvius terms it, and heart of deal, kept dry, rejecting the alburnum or white, is everlasting ; nor is there any wood which so well agrees with the glue, or which is so easy to be wrought. It is also excellent for beams, and other timber-work in houses, being both high and exceedingly strong, and therefore of very great use for bars and bolts of doors, as well as for doors themselves ; and, for the beams of coaches, a board of an inch and a half thick will carry the body of a heavy coach with great ease, by reason of a natural spring, which is not easily injured. It was fiir merly used for carts and other carriages. and also for the piles to build upon in boggy grounds. Most of Venice and Amsterdam is built upon such piles. For scaffolding also, there is none comparable to it. Under the head of fir may he classed cedar, a wood of great durability, but too expen sive to be used ill Britain.