Preservation of Timber. 



[JAN., 



to above, the students being members of one or other of the 

 Colleges, and their parentage not being known to the Depart- 

 ment. The figures supplied by Cambridge have, therefore, 

 not been included in the above returns. In the past three 

 years 231 students have attended the classes provided by the 

 Agricultural Department of this University. Of these 59 are 

 engaged in teaching or research, or are employed in super- 

 vising agricultural work in other countries, 26 are land- 

 owners or expect to inherit land, 17 are engaged in, or are 

 preparing for, land agency work, 13 are farming. The 

 occupations of the remainder are unknown, but it is probable 

 that many of them expect to inherit land or to become asso- 

 ciated with land management. 



The increase in the durability of timber which may be 

 brought about by the use of preservatives is a question of 

 considerable importance in the United 

 Preservation States in view of the large annual pro- 

 of Timber. duction of timber in that country, and 

 the subject has engaged the attention of 

 the Forest Service of the Department of Agriculture * since 

 1902. Although the experiments carried out by the Forest 

 Service were confined to the treatment of poles for telegraph 

 and telephone purposes, many of the results are of interest 

 to the English agriculturist from the point of view of estate 

 management.! 



Seasoning of Timber. — The question of seasoning neces- 

 sarily requires consideration before the use of preservatives is 

 dealt with, since proper seasoning not only prepares timber 

 to receive the preservative treatment, but under certain condi- 

 tions may be in itself a means of increasing its durability. 



Contrary to general opinion, the Forest Service found the 

 shrinkage taking place during the seasoning of poles to be 

 very slight, amounting, in seasoning from green to air-dry 

 condition, to about o'i in. or o'2 in. in the circumference at 

 the butt end, and from 0*15 in. to 0*25 in. in the circumference 

 at the top end of poles. The loss in weight during such 

 seasoning was found to be ordinarily from 16 to 30 per cent. 



* U.S. Dept. of Agric, Forest Service, Bull. 84. 



t Previous articles on this subject appeared in this Journal for May, 1905, p. 77 ; 

 Sept., 1906, p. 339, and July, 191 1 , p. 281. 



