GEOLOGICAL SECTIONS. 



45 



Fig. 14. 



To find amount of Dip, by diagram. For examples 

 of this, the cases in which the direction of dip was 



NOTE. The foregoing Rules were first published by the 

 Author in a communication to the " Geological Magazine " for 

 May, 1876 (p. 236). Mr. O. Fisher, after a careful examination 

 of the methods suggested, wrote to say that " Rule A is correct 

 for small dips for all practical purposes. It is not necessary that 

 the angle between the faces of the quarry should be obtuse. The 

 rule is equally true whatever be the angle. But Rule B, I am 

 afraid, is not correct. I should suggest the following mode of 

 applying the rule in case B." 



