266 Forestry Quarterly 



If, instead, 100 years is chosen, Sa and 5„ remain the same as 

 above, la with changed felling ages should change. It amounts 

 to 8400 feet, the formula now becomes 



100X70000 ,^^ 



e = = 100 = positive. 



50X8400-350000 



70000 



Hence 6 = 8400 tj^ =7700 cubic feet. If now we examine the 



100 



average age which the stands will have after 100 years, it will be 

 found that this age distribution corresponds to the normal stock. 



Beitrag zu den Fragen der Ertragsregelung mit besonderer Beruck- 

 sichtigung des schlagweisen Hochwaldhetriehes. Schweizerische Zeit- 

 schrift fur Forstwesen, January-February, 1915, pp. 13-24. 



UTILIZATION, MARKET AND TECHNOLOGY 



This paper gives the results of experi- 

 Home ments with saponified creosote and naphtha- 



Creosoting lene by the open tank (soaking) method. 



The experiments were conducted mainly to 

 determine whether the process of preservative treatment of tim- 

 ber by creosoting as now practised on estates could be modified 

 and cheapened without loss of efficiency. 



"It has been observed that treated timber used as fence posts, 

 absorbing a relatively small quantity of creosote, has been proved 

 after a quarter of a century's trial to possess lasting qualities, if 

 the preservative has been carried well through the timber. This 

 suggests that in the quantities absorbable by various timbers there 

 may be a suitable maximum beyond which it is unnecessary to 

 go, and also a minimum quantity below which it is not wise to go, 

 if the desired lasting qualities are to be obtained." 



For the purpose of controlling the amount of creosote used in 

 any case, the oil was saponified by the addition of a very small 

 proportion (J4 per cent or less) of caustic soda. This saponified 

 creosote can be diluted to any desired extent by the addition of 

 water. This results in improved penetration of the preservative 

 into the timber, particularly in the case of refractory woods. 



