142 WOODS OF COMMERCE 



as to correct warping. We are not here concerned with the manifold 

 uses of Birch bark — especially in Russia, Sweden, and Scotland — 

 for boxes, baskets, boots, boats, cordage, dyeing, tanning, and even 

 bread-making. The two forms known as Betula verrucosa Ehrh., 

 the *' Raubbirke " of Germany, and B. puhescens Ehrh., the ^' Haar- 

 birke," are here treated as one species. In Jamaica the name 

 Birch is appHed to Bursera gummifera, a tree in no way 

 similar, and in Tasmania to Dodoncea viscosa. [See Lignum- 

 vitse vi.] 



Birch, American, a trade name for the imported timber, which 

 is the product of more than one species, though chiefly of Betula 

 lenta, the Cherry Birch, and, to a much less extent, B. lutea, the 

 Yellow Birch. 



Birch, Black {Betula lenta L.). See Birch, Cherry. 



Birch, Black or White, of New Zealand {Fdgus Soldndri Hook, 

 fil. : Order CupuUferce), Maori '' Tawhai rauriki," Really a 

 Beech, but known in Nelson as " White," and in Wellington as 

 " Black Birch." Height 100 ft. ; diam. 4 — 5 ft. W 47. Hard 

 and very durable, and suited for fencing or fresh- water piles, but 

 liable to attack by the ship-worm. The names " Black " and 

 " Red Birch " are also apphed to Fdgus f4sca Hook, fil., a tree 

 reaching a greater diameter and with darker wood. '' Tawhai 

 raunui." S.G. 700. W 48-6— 53-25. p 202-3. 



Birch, Canoe (Betula papyrifera Marshall: Order Betuldcece). 

 ''White" or ''Paper Birch." Germ. '^Nachen Birke." Canada 

 and the Northern United States. Height 60 ft. or more ; diam. 

 3 ft. or more. Sapwood wliite, heart reddish-brown, with a fine 

 glossy grain. Rather heavy, hard, tough, and strong, not durable 

 where exposed to alternations of moisture and heat. Used for 

 bobbins, shoe-lasts and pegs, turnery, and extensively for paper- 

 pulp and fuel. A curl in the grain where the branches are given 

 off is sought after by Boston cabinet-makers for veneers. 



Birch, Cherry {Betula Unta L. : Order Betuldcece). "= Black, 

 Sweet," or " Mahogany Birch," " Mountain Mahogany." French 

 " Bouleau doux," Germ. '' Kirsche-Birke," Span. " Abedul dulce," 

 Canada and Eastern United States. Height 60—80 ft. ; diam. 

 3—4 ft. S.G. 762. W 37-5—48. Ash percentage -26. Relative 

 fuel value -759. Coefficient of elasticity 141,398. R 1,216 kilos. 

 Resistance to longitudinal pressure 619, to indentation 226 kilos. 

 Sapwood when first sawn distinctly yellow, with the heart a brownish 

 red. After seasoning the sapwood fades to a cream white and the 

 heart to a pnikish red. Heavy, hard, very strong, close-grained, 

 taking a beautiful satiny poHsh, not attacked by worms, and fairly 

 durable, but becoming duller after conversion. It presents the 

 " roll figure," seldom seen in any other wood. If the boards after 



