MAPPING 



119 



Fig. 11, underbrush; Fig. 12, swamps; Fig. 13, fresh- water 

 ponds and marshes; Fig. 14, salt-water ponds and marshes; 

 and Fig. 15, rice dikes and ditches. 



FIG. 2 



FIG. 3 



Platting Angles. In platting a traverse requiring great ac- 

 curacy, as, for example, a difficult railroad location, the method 

 of latitudes and longitudes given under Angular Surveying 



FIG. 4 



should be used. In ordinary land surveys or preliminary rail- 

 road surveys, the tangent method is most convenient. In this 

 method, the directions of the lines that are laid off to scale 



