Page:Cassells' Carpentry and Joinery.djvu/59

From Wikisource
Jump to navigation Jump to search
This page has been validated.
TIMBER.
43

So far as the texture and hardness of each is concerned, some of the former are really more difficult to work than the latter. For example, pitchpine, owing to its resinous nature, is usually more difficult to work than basswood, or the softer kinds of mahogany. The general distinguishing features of soft woods are:—All the trees bear cones and never have broad flat leaves. The timber usually has distinct annual rings formed of two layers, the inner one (known as springwood) being soft, porous, and pale in colour; the outer (called autumn wood) is harder, more compact, and rilled with resinous matter. The whole annual ring is formed of long tapering tubes, interlaced, and breaking joint with each other, and having a small portion of cellular tissue at intervals, and resinous matter in the interstices. Hardwood trees bear broad flat leaves, the timber is never resinous. The annual rings, owing to slower growth, are often much closer together than in softer wood. They are of more uniformity in colour and hardness, but have more or less distinct radial lines, consisting of thin, hard vertical plates, formed entirely of cellular tissue, the medullary rays or silvergrain or flower already mentioned.

Varieties of Timber.

Fir Timber, Converted.—Fir timber, when sawn into convenient sizes suitable for joiner's work, is called deal. It is brought into the market sawn into different widths, which are often classed as deals, or distinguished as battens, deals, and planks. They vary from 2 in. to 4 in. thick, but are mostly 3 in. thick, and from 8 ft. to over 20 ft. in length. All that are under 8 ft. in length are classed as ends, and are sold at a cheaper rate. When 7 in. wide and under they are termed battens; deals, from 8 in. to 9 in.; and planks when above 9 in.

Baltic Yellow or Red Deal.—The best yellow deal for building purposes is shipped from the Russian ports of Petersburg, Onega, and Archangel, and the Swedish ports of Söderhamn, Gefle, Stockholm, and Holmsund. Onega, Archangel, and Gefle supply deals of the best quality. The greater portion of the Swedish timber is coarse, but at the same time some of the very best deals, both yellow and white, come from Gefle and Söderhamn. The best Swedish deals run more sound and even in quality than the Russian, owing to the different way in which the timber is converted. A balk of Russian timber is cut into deals, etc., of one quality, and thus they show very many hearts or centres. In Swedish timber the inner and outer wood in the same balk are converted into different quality deals, the centre being put into the lower class; hence the high price put upon first-class Swedish deals. Deals cut from the centre of the log should not be cut into boards; 4-in. deals are in nearly all cases cut from the centre of the balk, and consequently are subject to shakes, and unsuitable for boards. Swedish 2-in. and 2½-in. deals of good quality are preferred to 3-in., as they are cut from the sound outer wood. Their value not being generally known, they do not fetch such high prices as the 3-in. deals. The export of deals from the Prussian ports of Dantzic, Memel, Stettin, etc., is almost entirely confined to yellow planks and deck deals (also called red deals), from 2 in. to 4 in. These are suitable for scantlings, framing of roofs, and many purposes connected with housebuilding, engineering, etc. The reason of the timber from the above ports being shipped in an unconverted state is that the wood, being grown in a warmer climate, is coarse in the grain, and could not compete in a converted state with the closer-grained exports from the more northerly ports of the Baltic. Baltic yellow deal or red deal is from the Pinus sylvestris, or Northern pine. The colour of the wood is generally of a reddish yellow or of a honey yellow of various degrees of brightness, annual rings about 1/10 in. wide, the outer part being of a bright and reddish colour. When knots occur they are from 1 in. upwards in diameter, and not very hard; they are of a rich red brown colour, and thin shavings of them are semi-transparent. This timber is stronger and more durable than white deal (Abies excelsa, described below).

Baltic White Deal or Spruce Fir.—This is Abies excelsa, and is used in the common qualities for the roughest work—scaffold