48 FOREST EESEKVE MANUAL. 



they are surveyed, without reference to their position in the 

 district. If, however, there is an opportunity to subdivide 

 the whole district, it is desirable that the numbering commence 

 in the north end and proceed southward in regular order. 



For this reason, and also to utilize the advantage of a com- 

 plete surveying squad as long as possible, before other reserve 

 work requires the breaking up of the party, the work of dis- 

 tricting and blocking should be pushed as fast as practicable. 

 The mapping, estimating, and description may be left for a 

 time when fewer men can be spared. The districting may 

 proceed independently of the blocking and should, preferably, 

 keep well ahead of it, though a district may be established 

 before all of its boundaries are run out and marked. 



Block maps should include such details as buildings, roads, 

 trails, streams, cuttings, fences, and mining or other claims. 

 The topography may be shown by dotted contour lines, of 

 which, to avoid confusion, there should never be more than 

 four in one block. This rule will prevent the use of a regu- 

 lar interval between them, and the height of each should be 

 marked, the lowest portion of the block representing zero. 



If the block is surveyed especially to enable description of 

 a tract covered by application, the proposed cutting area 

 must be outlined on the map. 



Block maps should be drawn with a hard, sharp pencil upon 

 ruled sheets furnished for the purpose by the Department. 

 In the absence of this, plain 8 by 10 paper may be used. A 

 scale of 12 inches to the mile should be adhered to in all cases, 

 and only one block is mapped on one sheet. 



The original map will be forwarded, through the supervisor, 

 to the central office, where copies will be made for the use of 

 the supervisor and rangers. 



ESTIMATING, 



No forest officer will be considered competent who can not 

 estimate standing timber. All work of this kind in the 

 reserves will be required to be done systematically and accu- 

 rately, and in all cases estimates must be accompanied by a 

 description of the method used. 



Most systems require knowledge of the contents, in cords 



