NEIGHBOURHOOD OF CORK. 



85 



riations in their composition, beds of a harder stone 

 being included in strata of softer materials, or the 

 reverse. But the secondary horizontal strata are 

 uniform, the stratum above being similar to the one 

 below. Sometimes, however, these horizontal strata 

 differ a little in colour for a few yards, but seldom 

 to a greater extent. 



These subordinate horizontal beds are short, the 

 lines of separation ceasing, and new ones, parallel, 

 but not continuous, appearing, at short intervals of 

 a few yards. These lines of separation are distinct 

 and waved, and are carefully attended to by the 

 quarrymen, whose operations they contribute to fa- 

 cilitate. 



The appearances which these subordinate strata 

 exhibit when the section is at right angles to the 

 line of bearing, are apt to lead an observer, at first 

 sight, to conclude that the rock is disposed in true 

 horizontal strata ; nor will he be convinced of the 

 mistake, until a more minute examination of the 

 fracture of the stone has pointed out the true 

 structure of the beds. 



Two forces have been operating upon the matter 

 of the rock when entering into its present state : 

 One, disposing the strata to assume a vertical po- 

 sition, and exercising absolute controul in arranging 

 the slaty structure and fracture of the stone ; while 

 the second, less powerful in its influence, and irre- 

 gular in its operations, has given rise to those wa- 



