MINING TIMBER. 573 



prejudicial to steel sleepers. No sleepers can yield a better 

 running road for traffic than the creosoted red-deal sleepers 

 of Pinus syh-estris from the Baltic, which are used almost 

 exclusively in Britain. 



In India, teak, deodar, sal, and Xylia dolaliriformis are the 

 chief woods used for sleepers, and 4 millions yearly are the 

 estimated requirements for the future. 



In America most sleepers are made from the longleaved or 

 pitch pine (P. 2)alustri} ; in Australia and S. Africa from 

 species of Eucalyptus, though much red-deal from the Baltic 

 is imported into S. Africa. Tr.] 



6. WIHH! ntii'il in r\n'ta. 



Palisades in fortresses are made of all kinds of wood, chiefly 

 coniferous. Platforms for guns and bomb-proof and other 

 sheltered parts of forts are made largely of all kinds of wood, 

 chiefly oak and Scots pine. 



7. Minin<i Tiinltcr. 



In spite of the large use of iron in supporting mine-galleries, 

 large quantities of pit-wood are used for this purpose, as well 

 as for lining shafts in pumping- works, etc. In Germany, the 

 annual production of 120 million tons of coal and lignite 

 require annually 3'6 million cubic meters of wood (126,000,000 

 cubic feet), while for all the German mines, 4 million cubic 

 meters of wood are required. Wood used in mines is exposed 

 to damp air, damp and frequently wet soil, and, in the deeper 

 mines, to a constant degree of comparatively high temperature. 

 Every circumstance, therefore, tends to favour the decomposi- 

 tion of the wood, and it lasts seldom more than 4 to 6 years. 

 If the demands were not so considerable, none but the most 

 durable oakwood ought to be used. It is, however, more 

 economical to use the wood which is locally more easily pro- 

 curable ; this is chiefly coniferous, of which larchwood is most 

 durable, then resinous Scots pinewood, but in Germany even 

 sprucewood is sometimes used. Among broadleaved trees 

 beech is used most commonly, and largely so when shod with 

 steel, as stamping hammers for pounding minerals. 



