88 - THE ADIRONDACK SPRUCE 
would be discarded by the lumbermen. The propor- 
tion of unsound hardwood trees varies considerably in 
different -parts of the Adirondacks, and it is extremely 
difficult to determine what proportion of cull should be 
allowed in the Park, because no satisfactory figures 
could be obtained for hardwoods cut in this immediate 
section. The number of board feet of apparently sound 
hardwood timber was first computed without making 
any deduction for cull, suitable allowance being made 
later in the estimate of yield. 
For the estimate of Birch the following table, recom- 
mended by Mr. James L. Jacobs, Superintendent of the 
Santa Clara Lumber Company, was used. 
TABLE 28 
STANDING BIRCH 
Diameter Contents 
in in 
inches. board feet. 
16 157 
18 292, 
20 302 
a2 400 
24 499 
The average number ot trees per acre and the aver- 
age diameter were determined from the valuation 
surveys, and the yield in board feet was found by mul- 
tiplication from the table given above. Only trees over 
fifteen inches in diameter were used in the estimate for 
Birch and Maple, as this is the average limit of the 
