38 ANOMALOUS CONDITIONS. 
hill of slate, which, towards its-summit turns off at 
an obtuse angle, which gives this rock a peculiar 
aspect. Mr. Hennah records an instance, where the 
slate seems as if thrust up by some violent impulse 
from below, between two beds of lime. I am of 
opinion that several similar instances as regards 
this appearance of the deposit of the rock, can be 
appearance as is displayed by sand on a very flat beach, on the 
retreat of the tide. This condition indeed, must have been taken 
on during the precipitation of the rock, and not by any force ex- 
erted from below. 
