122 FOREST commissioner's report. 



What method of cutting should be put on these lands to get 

 the most out of them in the long run ? 



Rate of '^^^^ ^^^^ thing necessary to determine is the 



growth. amount of growth upon individual trees. The 

 methods used for this purpose have already been stated in con- 

 nection with the report upon the Kennebec drainage, but they 

 will bear retelling here. The real basis for this is the detail 

 study of trees, including the count of annual rings and meas- 

 urement of their thickness at different points in the trees' 

 length. More than 300 spruce trees have been thus meas- 

 ured by the writer in the employ of the U. S. Forestry 

 Division, and during the course of the season's work some 

 fifty others, cut into shorter sections and selected in accor- 

 dance with the purposes of the Avork in hand, have been 

 added to the number. From this work one main result is the 

 determination of the rate percent at which trees are growing. 



A short cut to the same result, allowing more trees to be 

 orought into view without multiplying the lal>or in the same 

 ratio, is furnished by Pressler's tables. These, which are 

 based on measurements similar to those just mentioned, give 

 approximately, merely from the diameter of a tree 4 to 5 feet 

 from the ground and the thickness of the outer rino-s at the 

 same point, the rate per cent at which the tree is growing. 

 Checking the use of these tables by exact measures on our own 

 timber, they furnish us with very valuable information. 



During the time spent on the Androscoggin, some 300 

 trees were tested for this purpose, and the percentage of their 

 growth determined. The trees so examined ran from 7 to 13 

 inches in diameter, and Avere of all degrees of thrift. It 

 seemed necessary for present purposes to ascertain the growth, 

 not of thrifty trees only, but of average trees through the 

 country, and in order to do that, I made it a practice, when- 

 ever I set out to fill a page with these notes, to take every 

 tree of the desired sizes that was come to. The trees so 

 studied were well" scattered over the country, and they are 

 sufficient in number, it would seem, to furnish a reliable basis 

 for drawing general conclusions. 



