FOREST DIVISION 39 



comings of the preliminary survey, as stated above. Since the 

 mapping and description work is done in detail, this method is a 

 combination of extensive and intensive work, with doubtful justi- 

 fication. * 



FIGURE i. Primary and Secondary "Control" or base-lines. Line I, 2, 3, 

 4 is here the principal line, a, b, c are secondary lines. Dotted lines m, n, 

 and o are lines of travel of the crew estimating and describing the timber^ 

 At i is a Section Corner, here used to "tie in." 



b. Use and Value of Subdivision in Forestry. 



The value of a good permanent subdivision on the ground not 

 only in Survey or examination of the property, but also in Utiliza- 

 tion, Protection, Silviculture and even in Improvements, but most 

 of all in proper Administration and Bookkeeping, is very great. It 

 was fully appreciated by Cotta a hundred years ago, and Martin 



* These base- or control-lines may be established by a crew of four men ; 

 transitman, recorder, rodman, and axman (changes in this to suit timber, 

 etc.). This crew in fair country can do two miles per day at an expense of 

 about $10.00 per mile. Stations usually every ten chains, with number and 

 altitude. This crew maps along line; measurement by stadia. 



