Page:EB1911 - Volume 26.djvu/1019

 Norwegian timber is stencilled with the shipper’s initials in blue letters painted on the ends. Swedish timber is stencilled with red letters or devices, the inferior qualities in blue. Prussian timber is scribed on the sides near the middle. By scribing is meant that the distinguishing letters are roughly cut in with a gouge. Russian timber is dry-stamped or hammer-branded on the ends. American (Canadian) timber is stencilled in black and white. United States timber is marked with red chalk on the sides.

To fit timber for use in building construction the superfluous sap and moisture contained in the green wood must be evaporated, either by natural or artificial means. During this process the wood shrinks considerably, and unless much care and attention are given to the drying wood it will warp and shake sufficiently to unfit it for practical uses. After the log is converted into scantlings, or “lumber,” as it is termed in America, it is stacked in the timber yard under covered sheds with open sides to enable it to “season.” The wood is carefully piled in tiers or courses, with strips

of wood about an inch thick between each layer, so as to allow of the free circulation of air all round each piece. This is the natural and best method of seasoning, and timber treated in this way is more durable than that seasoned by artificial methods; the time taken, however, is much longer. For joiners' work the drying of the wood is often hastened by stacking the timber in well-ventilated rooms kept at a temperature of from 80° to 150° F. The time taken in seasoning wood by this desiccating process is not more -than one-tenth of that occupied in the natural or open-air method. Where it is convenient, timber is sometimes treated with a water seasoning process which enables it to be more easily dried. The wood is placed in a running stream and so tied or chained down as to be entirely submerged. The water enters the pores of the wood (which should be placed with the butt end pointing up stream) and dissolves and forces out the sap. After about two weeks in this position it is taken out and stacked in open sheds to be dried in the natural way, or treated by warm air in special chambers. Steaming and boiling are sometimes resorted to as artificial means of seasoning, but not to any great extent, as the timber deteriorates under such treatment, and the cost of the process is in many cases prohibitive. When wood is required to be bent, however, this is often the method that is adopted to soften the material, so as to allow it to be bent easily. The time allowed in the English government dockyards for the natural process of seasoning for hard woods such as oak is, for pieces 24 in. sq. and upwards, 26 months; from 16 in. to 20 in. sq., 18 months; from 8 in. to 12 in. sq., 10 months; from 4 in. to 8 in. sq., 6 months. Soft woods are allowed half these periods. When the wood is required in a “dry” state for joiners' work, twice the length of time is given. Planks are allowed from a half to two-thirds of the above time, according to their thickness.

The timber used in building is obtained from trees which may be classed under two heads: (1) Coniferous or needle-leaved trees; (2) the non-coniferous or broad-leaved trees.

Coniferous Trees.—This class includes most of the soft woods which furnish timber for the framing and constructional portions of nearly all building work. They are also used for the finishing joinery of the ordinary class of building. The numerous varieties of pine which are used. more extensively than any other kind of wood are included in

this class.

The northern pine (Pinus sylvestris) has a number of other names and may be referred to under any of the following: Scotch fir, red deal, red fir, yellow deal, yellow fir, Baltic pine, Baltic fir. It grows in Sweden, Norway, Russia, Germany and Great Britain, and often gets a name from the port of shipment, such as Memel fir, Danzig fir, Riga fir, and so on. The colour of the wood of the different growths of northern pine varies considerably, the general characteristics being a light reddish yellow colour. The annual rings are well defined, each ring consisting of a hard and a soft portion, respectively dark and light in colour. No medullary rays are visible; the wood is straight in the grain, durable, strong and elastic, easy to work, and is used by the carpenter for internal and external constructional work, and by the joiner for his fittings. Tar, pitch and turpentine are obtained from the wood of this tree, which weighs from 30 to per cub. ft.

The white fir, or Norway spruce (Abies excelsa), is exported from Russia, Sweden and Norway, where it grows in enormous quantity. It is the tallest and straightest of European firs, growing with a slender trunk to a height of from 80 to 100 ft. Like the northern pine, it is called by several names, such as “spruce,” “white deal,” “white wood,” “Norway fir.” The colour of the cut wood is a very light yellowish or brownish white, the hard parts of the