52 VOLUME OF WHOLE WOODS. 



a. DraudVs Method. 



Draudt selects in each class the same percentage of sample 

 trees, thus ensuring that 



S l S 2 S 8 



Let be 



If p per cent, of the trees in each class are taken as sample 



CALCULATION OF VOLUME BY INCH CLASSES, FOUR GROUPS, AN! 



FOR ONE ACRE OF SCOTCH 



