68 THE PllINOlPAL 0SES OF WOOD, 



always unsuitable, since their bleaching would be unnecessarily- 

 laborious and costly. Heartwood is also inappropriate, firstly, on 

 account of the dark colour, and secondly, on account of the encrust- 

 ing matters that cause the sapwood to become heartwood. It is 

 evident that the wood should also not be too hard. Poplars, wil- 

 lows, the firs, most of the pines, species of Sterculia, Boswellia, 

 and other soft and rapidly growing species will doubtless prove 

 excellent for the purpose. The best wood is furnished by stems 

 not exceeding 1 foot in diameter. 



Section II. — Firewood. 



In spite of the innumerable different requirements of the popu- 

 lation in respect of timber, the demand for firewood is many times 

 larger, and will not only remain so, but will even increase in 

 greater proportion with advancing civilisation and wealth and 

 higher prevailing standards of comfort. Considering fuel for 

 cooking purposes alone, the annual consumption, at the very mo- 

 derate daily rate of 1 fb. per head per day, must already exceed 

 300 millions of solid cubic feet. Insufficiency and badness of com- 

 munications keep down the demand as well as the supply brought 

 into the market, and millions of cubic feet rot or stand unprofit- 

 ably in the forest owing to impossibility or prohibitive cost of 

 export. 



Firewood may be used for two sets of purposes, viz., (1) directly 

 for the heat and light it gives out in burning, and (2) indirectly 

 for certain products which form when it is burnt. 



(1). Wood humt for heating and lighting purposes. 



Wood may be burnt until it is consumed, or it may be burnt 

 only to a limited extent and converted into charcoal for future use.* 

 Wood charcoal gives out the highest calorific effect of wood, 

 and is hence alone used for smithy and foundry work and for other 

 purposes which require not only a steady and prolonged, but also a 

 very intense, heat. For glass-making and ore- smelting also charcoal 

 should exclusively be used, but owing to the primitive condition of 

 the arts in India, the hardest and heaviest woods are sometimes 

 employed. For the production of steam (as for driving machinery, 

 soap-making, laundry work, &c.), charcoal is the best, but with 

 a strong draught the harder woods yield completely satisfactory 

 results (the softer woods are not used at all, because they burn too 



* The manufaoture of charcoal will be described in detail in Fart III. 



