CLEAEING THE CEOP 165 



To find the cubic contents of the tree by the use of 

 the form factor, the contents of the cyHnder — viz., 25 

 cubic feet — is multiphed by the form factor 



25 



•47 



11-75 11-75 = 11 cubic feet 9 inches. 



To find out the form factor for a certain class, species,. 

 or size of tree, measurements cf a large number should 

 be taken, the form factor worked out for each stem, and 

 all the results added together and divided by the number 

 of poles measured, to arrive at the average factor. 



The figures vary considerably for each tree. 



When collecting some figures in a mixed wood thirty- 

 five years of age, I found that the factors for individual 

 stems of Corsican Pine varied from -59 to -40, and for 

 Larch from -58 to -42. The average for Corsican Pine 

 was '47 and for Larch -48. 



How to Tell the Age of Trees. 



With hardwoods this is hardly possible while the trees 

 are standing, but with conifers in the pole stage the age 

 is found by counting the whorls or rings of branches from 

 the top to the bottom, and allowing about two or three 

 years for the space between the bottom whorl and the 

 ground for the seedHng stage. (Some species — Banks 

 Pine, for instance — put on two or even three shoots in 

 one year, making it impossible to tell their age by this 

 method.) When the trees are felled, the age can be fairly 

 accurately obtained by counting the annual rings from 



