METHODS OF MAP MAKING 117 



fore, save time and money if the interior features can be 

 tied to them. 



3. Topographic maps of forest property should be 

 especially clear in respect to road lines and other points of 

 importance in lumbering operations. The map-maker 

 should, therefore, understand these operations. It will, 

 also, save time and money if topography and timber can 

 be examined together, at the same time, and by the same 

 man. 



With these principles in view, the following are methods 

 recommended for the production of forest maps. It is 

 well in discussion of the matter to divide the work into 

 two classes that on small tracts, where close work is 

 required, and that on larger tracts, where different methods 

 must be employed and a lower standard of accuracy may 

 be allowed. 



2. MAPPING SMALL TRACTS 



A tract of eighty-nine acres, well timbered and of strong 

 relief, that was surveyed by the class of 1907 in the Harvard 

 School of Forestry will serve as illustration. The following 

 steps were taken in the process. 



1. Boundaries surveyed by compass and chain ; marked 

 stakes left every twenty rods ; bounding lines and corners 

 remarked. Two days' work for three men, more if there is 

 special difficulty with the old boundaries. 



2. Elevation of one convenient point ascertained or 

 assumed, and levels run over the roads crossing the tract, 

 leaving bench marks plainly marked every twenty rods or 

 so. Levels, also, run down to point x. (See page 119.) 

 One half day's work for two men. 



3. Outlines of tract plotted to scale on paper; this 

 pinned on traverse board with meridian of survey parallel 

 to N and S edge of board ; roads run in with the chain and 

 position of bench marks taken. One half day's work for 

 three men. 



4. Sheet on the board without the tripod taken into the 

 field, a scale serving for alidade; detail mapped in by 

 short foot traverses from the known points ; elevations got 

 partly by aneroid, partly by hand level. One day's work 



