20 



girth against which it is drawn. Each full compartment represents 

 2U trees, and the whole line of five compartments 100 trees of one 

 and the same girth-class. After the survey is over, the total basal 

 area of the trees of each girth-class is calculated and entered in 

 the proper column. Lastly, the numbers of the tvecs and the basal 

 areas are totalled up. 



Perhaps a more convenient method of recording the number of trees is the 

 one universally employed in France. It is as follows : Each group, represent- 

 ing 10 tree*, consists of two upright rows of four dots each, joined by two 

 diagonal lines, which represent respectively the ninth and tenth trees, thus 



K=10; :\?=; H=8| |: = 7; |;=6; 



and so on 



The subjoined form of field-book has been in general use in the North- West 

 Provinces and Oudh for more than ten years, and can hardly be improved upon 

 for enumeration surveys in which the classes include a large range of diameter 

 and the forest is very irregular. Some of its advantages are (i) that it requires 

 very little ruling, (ii) that it may be easily prepared from day to day by the 

 recorder himself, and (iii) that, as the width of its different columns and com- 

 partments can, for that reason, be varied to suit the composition of the crop to 

 be surveyed, a whole day's work, comprising several thousand trees, can be got 

 into a single opening of the book. The total numbers of trees of each species 

 (or group of species) and diameter-class is written in the right hand lower corner 

 cf its own compartment. 



1- , . 1. 1 



-CoMPARTMBirr- 



