METHODS OF MAP MAKING 



119 



Alternative Methods. 1. Compass and chain may be 

 used to survey the roads and the plotting done off the field. 

 This is most convenient in wet weather, but when a traverse 

 board is at hand and can be used, it will be found the 

 quickest method of survey and the least liable to error. 



Diagram showing 

 Method of Survey 



Lines surveyed & chained 



Points marked for refprpnna t i | i 



Levelled lines 



Bench marks O O O 



Traverses with barometer 



or hand level 



2. Transit and stadia might be substituted for both 

 level and traverse board in the survey of the roads, and, 

 where the woods are open enough, in mapping the detail 

 of the topography. This method involves much comput- 

 ing, is generally cumbersome, and except in the hands of a 

 skilled and practiced man is liable to give rise to error. 



