214 TIMBER AND TIMBER TREES. [CHAP. 



shoes, and soles for shoes, these being considered far 

 superior to any made of other descriptions of wood. It. 

 is also a most valuable article of fuel. 



Beech is durable if kept wholly submerged in water 

 or mud ; it is also durable if kept quite dry, but if left 

 exposed to the alternations of the weather, it soon becomes 

 doated over with yellowish spots, and rapidly decays. 



I had no suitable pieces available for experimental 

 purposes, to try its transverse strength, but the tensile 

 I ascertained by experimenting on three pieces, the 

 average giving 4,853 Ibs. per square inch ; tried vertically 

 upon four pieces the average was 3*812 tons per square 

 inch. The specific gravity of the seasoned wood varies 

 from 700 to 720, and averages about 705 . 



THE BIRCH TREE (Betula alba, or Common Birch) 



is found in nearly every country in Europe. In Bosnia, 

 Turkey, however, I only met with it on the skirts of 

 forests upon the mountains at a considerable elevation. 



The European Birch grows naturally a little crooked 

 in the stem, with light, oblique branches, slightly droop- 

 ing at the extremities, and attains, sometimes, the height 

 of 50 feet, with a diameter of 18 inches, but generally it 

 is of very moderate dimensions. It flourishes on a poor 

 soil in any exposed situation, and is very hardy. 



The wood is of a light brown colour, moderately 

 hard, plain and even in the grain, and is easily worked ; 

 but it is neither strong nor durable, and is therefore 

 unfit for building purposes. Its chief uses are for cabinet 

 work, chair-making, turnery, and light wares generally. 

 The bark is smooth, thin, white in colour, and is used in 

 tanning. Birch timber is imported in a round state and 

 with the bark on from the North of Europe to our 



