TIMBER (FE., Bois dceuvre; GER., Nutzholz).
Properly speaking, the term " timber " is eonfined to those kinds of wood which are eligible for building purpoaes ; but in the preaent article, it will be extended to embrace all useful woods, except such as have been already deseribed under Drugs (Quassia, p. 820); Dyestuffa (Barwood, p. 855 ; Brazil-wood, p. 856 ; Camwood, p. 856 ; Logwood, p. 862 ; Sanders-wood, p. 867 ; Sapan wood, p. 867); Perfumea (Sandal-wood, pp. 1527-8); and Tannin (Quebracho, p. 1988). They will be arranged in alphabetic order. The terms used in describing the eharactera of the various woods may be explained once for all. The " cohesive force" is the weight required to pull aounder a bar of the wood in the direction of ita length; the figures denoting the atrength, tough neaa, and stiffness, are in comparison with oak, which ia taken as the standard, and placed at 100 in each caae ; the " eruahing-foree " ia the reaistance to eompreaaion ; the " breaking-weight " is the weight required to break a bar 1 in. sq. supported at two points 1 ft. apart, and the weight suapended in the middle.
For more detailed information regarding the peeuliar propertiea of building-wooda, and the many methods of preaerving timber, the reader is referred to the new editiou of Tredgold's Carpentry, by Hurst, and to other works quoted in the Bibliography at the end of this article; a copious list of books ou foreatry will be found in Daydon Ja.ckaon's 'Vegetable Technology.' Acacia or American Locust-tree (Robinia pseudo-acaciu).—Thia beautiful tree, of eon aiderable aize and very rapid growth, inhabits the mountaina of America from Canada to Carolina, its trunk attaining the mean aize of 32 ft. long and 23 in. diam. The aeasoned wood ia much valued for ita durability, aurpaasing oak. It is admirable for building, poets, atakes, palings, treenaila for ahipa, and other purpose& Ita weight is 49-56 lb. a cub. ft.; cohesive force, 10,000-13,000 lb. ; and the strength, *illness, and toughness of young unseaaoned wood are respeetively 95, 98, and 92.
Alder (Alnus glutinosa).—This small tree inbabita wet grounda and river-banka in Europe and Atha, aeldom exceeding 40 ft. high and 24 in. diam. The wood ia extremely durable in water and
wherever it is eonstantly wet ; but it soon rots on exposure to the weather or to damp, and is much attacked by worms when dry. It is soft, works easily, and earves well ; but it is moat &deemed for pilea, sluices, and pumps, and has been much cultivated in Holland and Flandera for sueh purposes. Its weight ia 34-50 lb. a cub. ft. ; cohesive foree, 5000-13,900 lb. ; atrengtb, 80 ; atiff neaa, 63 ; toughneas, 101. It is one of the woods used in making gunpowder (see p. 882).
Alerce-wood (Callitris guadrivalvis).—Thia ia the celebrated eitrus-wood of the ancient Romans, the timber of the gum sandarach tree (aee pp. 1681-2). The wood was eateemed above all othera for roofing templea and for tables, and is employed in the eathedral of Cordova. Among the luxurious Romano, the .great merit of the tables waa to have the veins arranged in waving lines or spirala, the former called " tiger" tables and the latter " panther." Others were marked like the eyes on a peaeock's tail, and °there again appeared as if eovered with dense masses of grain. Some of theae tables were 4-4i ft. diam. The apecimens of the tree now existing in S. Morocco resemble small eypressea, and are apparently shoots from the atumps of treea that have been eut or burnt, though possibly their stunted habit may be due to aterility of soil. The largest seen by Hooker and Ball in 1878 were in the Ourika valley, and were about 30 ft. high. The stems of the treea swell out at the very base into roundish massea, half buried in soil, rarely attaining a diameter of 4 ft. It ia this basal swelling, whether of natural or artificial origin, which affords the valuable wood, exported in theae daya from Algiera to Paris, where it ia uaed in the richest and moot expensive cabinet-work. The unique beauty of the wood will alwaya eommand for it a ready market, if it be allowed to attain sufficient size, and the tree is eertainly deserving of earnest attempt to naturalize it in the botanic gardens of some of our tropical colonies, betbre it becomes extinct at the bands of the apathetic Moors, who are wasting the wood for building and fuel.