Geological Relations of the East of Ireland. 139 
which the stone-cutters were gradually cutting down. It was 
obviously composed of parallel layers from one foot and a half to 
three feet and a half thick, ranging north and south, and dipping 
70° east. But, although most of the seams evidently descended 
into the earth, some of them appeared to terminate at two feet above 
the ground, from which the mass protruded. 
But, in general, the rock appears in the quarries, as, for example, 
in those of Macreddin and Glencree, to be separated by cross fissures 
into rude rhomboidal and other quadrangular masses ; sometimes, 
however, there is an obvious disposition toward a spherical form, 
as in Knackaderry quarries, in the glen of Imale. Here the rock 
appears to be divided by parallel seams into strata five and six feet 
thick, ranging 15° south of east and north of west, and dipping 
7 5° toward the south ; but these strata are again separated by other 
joints in such a manner, that each stratum seems composed of rude 
spherical masses, surrounded and enveloped by concentric lamellar 
layers. I have observed a similar appearance on the coast between 
Seapoint and Dunleary ; and between the latter place and Dalkey, 
this tendency toward a stratified form, or to that of rhomboidal, 
tabular, or columnar masses, may be frequently remarked. These 
appearances may be considered perhaps as exhibiting the dissection 
of the structure of the granite on the great scale, the distinct con- 
cretions being separated and becoming obvious by the influence of 
the atmosphere. Of this description are also the three protuberant 
rocky masses, from whence the Three Rock Mountain has its name, 
which bear some analogy to the granite Tors of Cornwall ; and 
similar masses occur on granite in other countries. 
