30 



FIELD GEOLOGY. 



condition of things, and assign its proper place to the 

 line of division. 



Traversing. In surveying a district of which it is 

 necessary or desirable to map very accurately the out- 

 crop of the strata, the ground must be gone over much 

 more closely than is indicated by the preceding exam- 

 ples. It then is well to follow the lines of ditch and 

 fence by which the area is intersected, as these serve to 

 guide one in traversing all the ground without going 

 twice over any portion. Such lines are, as a rule, some- 

 what irregular, and occasionally too far apart for the 

 purpose, when they must be left and the intervening 



Fig. 9. Showing Two Methods of Traversing Ground. 



spaces walked over. The above diagram (fig. 9) shews 

 two very useful methods of traversing ground one on 

 each side of the main road the dotted line, starting 

 from the church, traces the path along which the walk is 

 taken. It will be seen that these dotted lines cover the 



