THE PROSPECTOR'S HANDBOOK. 



The above calculation assumes that the surface is hori- 

 zontal. Should, for instance, the outcrop be traced on the 

 hill side, then it would be necessary to find also the area 

 of the wedge-like body of ore, bounded by two parallel 

 planes, one plane perpendicular to the base, the basal one, 

 and also that of the slope. The area of such a wedge 

 would be half that of one such as represented in Fig. 70. 





