GEOLOGICAL MAPPING. 



11 



beneath this is frequently found a subsoil consisting of 

 the'disintegrated upper portion of the rock on which it 



rests. To ascertain the kind 

 of rock, these, or at all events 

 the former, must be pene- 

 trated. 



Almost every one who 

 follows geological pursuits 

 has a hammer to suit his in- 

 dividual fancy, and so long- 

 as it is capable of breaking 

 up a good-sized stone its 

 fashion is immaterial. But 

 for the purpose of drawing- 

 lines it will be found con- 

 venient to have the tail of 

 the hammer drawn out into 

 a chisel-pointed pick, 3 or 

 4 inches in length, with a 

 slight downward curve 



(fig- 3). 



With such a pick one can 

 easily dig down through a 

 foot of surface soil, or cut 

 away the face of clay and 

 sand in pits, banks, and cut- 

 tings. Its outer side should 



be bent into a curve de- 

 Fig. 3. Hammer, Pick, and _. 



Spud combined. scribed by a radius, 1 foot 



in length for a pocket ham- 

 mer, and 18 inches for one with a long handle such as 

 would answer also for a walking-stick. Some prefer 



