870 JOURNAL OF I'ORESTKV 



diameter-growth and the diameter-height curves. In the above outline 

 the height-growth curve is prepared direct by standard methods. Sec- 

 ondly, the various groups of data were secured from separate sets of 

 trees ; the volume table data from one set of trees ; the stump diameter- 

 growth data from another ; the d. b. h.-height data from a third. The 

 disadvantages of these two methods of procedure were pointed out in 

 the instructions given at the Yale camps, but were not followed out for 

 practical reasons and because the main purpose of the work was in- 

 structional. With the gathering of all data from one set of trees and 

 the accurate correlation of the same, it is believed that the resulting 

 tables will be of sufficient accuracy to serve most practical needs except 

 for the higher grades of scientific investigation. The above outline, it 

 is believed, provides for this in a satisfactory manner; but the writer 

 wishes to disclaim having any original contribution to the basic prin- 

 ciples of the system. The outline has been prepared with the object of 

 encouraging the making of more numerous growth studies by foresters 

 placed in positions where they find it difficult, from a practical stand- 

 point, to undertake an investigation requiring the expenditure of a 

 large amount of labor and the services of an organized crew for a 

 considerable period. 



