11 G INDUSTllIAL USES OF WUOD. 



in the frame-work of timbered houses, aud beech is often 

 employed for this purpose. 



Amongst foreign woods, imported from Algeria, Florida, 

 Canada, Australia, &c., chiefly belonging to the species, Qucrciis, 

 PiiiHS, Abies, Taxns, Ta.vodiam, Cnprcssus, Cednis, dr., that of 

 the Pitch pine {Piiiiis aiistraUs), on account of its great durability 

 and strength, beauty of grain and comparative cheapness, has 

 been recently in great demand. 



[Of Indian woods, the teak, deodar, blue pine (P. exceha) and the 

 sal {Shorea rohusta) afford some of the best building material, but 

 each province (especially the moister regions of Bengal, Assam, 

 Burma, Bombay and Madras) possesses a few other species yielding 

 durable timber. By far the larger number of Indian trees are greedily 

 devoured by the white ant, however well they may be seasoned, and 

 this greatly restricts the possible selection of timbers to be used for 

 buildings. — Tr.] 



Section III. — Timber used on, or in, the Ground. 



"Woods used in the form of piles for foundations in yielding 

 ground, or to support road-embankments ; also woods used in 

 aqueducts, roads, railways or mines, come under this head. 



1. Wood used ill l-'diouhttioits of Biiildiin/s. 



Where buildings arc constructed on yielding soil, a foundation 

 is frequently made for them by driving piles 8 — 12 inches in 

 diameter, and 10 — IG feet long, into the ground, sometimes 

 in several tiers one above the other, until a firm foundation 

 has been secured. This frequently takes a very large quantity 

 of timber. 



Wherever these piles are not completely under water they are 

 extremely liable to rot, owing to the variable moisture in the soil 

 which is not usually sufficient to exclude the air, and to the usually 

 moderate temperature of the soil. Hence the most durable 

 woods are used for this purpose, such as oak and resinous 

 conifers, chiefly larch and Scotch pine. 



Wherever the soil is permanently wet, alder-wood may also be 



