New York Agricultural Experiment Station. 315 



found my estimation was approximate!}^ 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 hemisplieroid 

 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 cj^anide 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. > 



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 tre^. 



