100 A MANUAL FOR NORTHERN WOODSMEN 



Another method of working is by intersections. For 

 this, it is necessary to have two known points or a measured 

 base. The instrument is set up at one of the known 

 points, and, the alidade being pointed at the other, a line 



Plane Table Map 



ROUND LAKE 



Washington Co. 



Maine 

 C. A. Gary 1907 



Area 343 Acres 

 . Scale of Feet 



1500 2000 2500 



is drawn and the known distance scaled off upon it. 

 Then, from that end of the base line representing the 

 point occupied, rays are drawn in the direction of other 

 well-defined objects on the shore which it will be desir- 

 able to locate. Flags may be used to define them, but 

 natural objects will often suffice. The instrument is then 



