286 TIMBER 



ground as railway sleepers and in sea water it proved a 

 failure after a very short life. It is now but little used. 

 The approximate costs of treating timber are as follows : 



Per cubic foot. 

 Burnettizing (Zinc Chloride process), 



Germany 2rf. to 2^/. 



Burnettizing (Zinc Chloride process), 



United States .... 2|d. 2f J. 



Zinc Creosote process, Germany . 2^d. ,, 3d. 



,, United States 4d. 



Zinc Tannin process, United States . 3(/. ,, 3J<7. 



Creosoting, United States . . l^d. 



North of England . . 4d. 5d. 



,, Germany . . . 4Jrf. 



Kyanizing, North of England . . 9d. 



It will be noticed that the cost of creosoting in America 

 is more than double the cost of treatment by the zinc 

 chloride process, which is the one in general use there ; and 

 this is the reason why the latter has been until recently 

 almost exclusively employed. 



When we consider the enormous and increasing quanti- 

 ties of timber which are being used yearly, and that we can 

 look to the not far distant future when the world's chief 

 forests of supply will be depleted, and when we know that 

 any of the artificial methods of treatment in use will 

 increase the life of timber for years, that some will double 

 and treble it, that it is not only a yearly saving, but neces- 

 sitates much fewer renewals of structures and less incon- 

 venience to trade and traffic, it will be seen that the 

 artificial treatment of timber is an important question for 

 the engineer and architect. It is of course a matter of 

 & s. d. whether he will by some satisfactory system utilise 

 the cheaper timbers at hand by paying even 25 per cent. 



