684 JOURNAI. OF FORKSTRY 



The second chapter deals with the volumes of trunk in relation to 

 site. The third with the volume of trunk in relation to diameter and 

 total height. There is an elaborate classification table showing the 

 distribution of the 1,963 trees. 



Chapter IV deals with volume of trunks and height on breast high 

 diameter ; also the form factors. This is followed by detailed dis- 

 cussion. 



The discrepancies of various formulae used are set forth. There is 

 a summary of form factors based upon the relation of the volume to 

 the perfect cylinder as a unity. 



There follows a volume table (in units of 10 cubic feet) showing 

 the results of the calculations according to d.b.h. (which is usually 

 taken at 4 feet even for experimental purposes) and height in units 

 of 6 feet ("Ken"). 



The second part deals chiefly with the discussions of previous ex- 

 perimental work along these lines. This includes a large amount of 

 mathematical demonstrations of the principles involved. 



A. B. R. 



• 

 Rate of Grozvth of Conifers in the British Isles. Bulletin No. 3 of 

 the Forestry Commission. London : His Majesty's Stationery Ofifice, 

 1920. Pp. 6. Price, 3s. 



This comprehensive study of the growth and yield of planted conifers 

 in England, Wales, Scotland, and Ireland, is the outgrowth of the war. 

 At that time many of the older stands were being cut so that the oppor- 

 tunity was unique for the collection of statistics. The result is the 

 present publication, which deserves the highest praise. 



The collection of data was begun in England in August, 1917, under 

 the Forestry Branch of the Board of Agriculture. Careful instructions 

 as to method .were issued to the officer in charge of the field work, and 

 though certain modifications became necessary in course of time, by 

 the end of the first year the final lines had been established. These 

 instructions are embodied in Bulletin No. 1 of the Forestry Commis- 

 sion. ("Collection of Data as to the Rate of Growth of Timper.") 



In December, 1917, a survey on the same lines was begun in Scotland 

 under the Board of Trade, Timber Supply Department (Scotland). 

 The same methods were used, and the officer in charge of the unit was 

 previously attached for a time to the original party in order to insure 

 uniformity. The work was extended to Ireland in February, 1919, 



