New YorK AGRICULTURAL EXPERIMENT STATION, 315 
found my estimation was approximately correct.” The 
diameters given in table indicate that the measurements were 
taken through the widest portion of the tree. Now a cylinder 
whose height is the same as the height of a given tree and its 
diameter the diameter of the tree through the widest portion, 
surely contains more cubic space than could be included under a 
tent thrown over the same. Adding half the difference between a 
cylinder and a sphere, the height of one and the diameter of the 
other being the same as the height of the tree, to the contents 
of the cylinder, makes the contents of the tented tree much more 
than they should be. 
All trees, no matter what their shape, when covered with a 
tent form approximately half a spheroid or ellipsoid, whose 
major axis is twice the height of the tree and minor axis the 
diameter of the tree through its widest portion. In most cases 
the contents of the tent will be slightly less than a hemispheroid 
of the same height and diameter. Hence we have the following 
rule which is accurate enough in actual field work: Multiply - 
the height of the tented tree by the square of the diameter 
through the branches, and this product by the constant 5236. A 
more simple rule is to multiply the height of the tented tree by 
the square of the diameter and this by one-half the number of 
grams of potassium cyanide to be used per cubic foot. The prod- 
uct will be the total amount, in grams of potassium cyanide 
required for each tree. To reduce this to ounces divide by 28.35. 
This rule applies only to tented trees. 
Although in itself the foregoing rule is simple, its application 
is not so easy. It is not an easy matter to estimate the dimen- 
sions of a tented tree and much depends upon the skill of the 
operator in fixing the size. rie 
Most tables are intended as a guide for guessing at the con- 
tents of a tented tree, although some writers have failed. to state 
whether measurements should be made before or after tenting 
the tree. 
