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ing in it; we then come to the true trap, which at the river is 

 not wide. Inrinnediately upon the northern side of the trap, the 

 sandstone rock re-appears with its usual dip to the northwest, but 

 presenting some remarkable modifications. These may be seen 

 opposite the toll-house, at the village of Rocky Hill, upon the 

 canal, in a quarry one hundred feet to the north of the trap rock. 

 The inclination of the strata being not more than 15°, the lower 

 beds in the quarry cannot be fifty feet remote from the subjacent 

 trap. They are filled to such a degree with various crystalline 

 matters, and show therefore so much inequality of composition 

 and hardness, as to be unfit for building stone. As we descend 

 in this quarry, the rock departs from its character of a sandstone, 

 though at a certain depth the change of texture is precisely that 

 which is desirable in a material ordinarily too easily acted on by 

 the weather. About one hundred feet from the trap, the rock has 

 the condition of a very close-grained, compact, and reddish, or 

 purplish sandstone, of a somewhat argillaceous texture, while it 

 is full of dark spheroidal kernels or nodules, of a radiated struc- 

 ture, of the dimensions of a pea or less. The nature of the 

 mineral is rather obscure, from the absence of all definite crys- 

 talline character. This stratum is a very durable rock, and is 

 extracted in regular masses, furnishing a building stone which is 

 in considerable request. In the middle of this stratum, there is a 

 thin bed, four feet wide, which seems originally to have been a 

 sandstone containing much felspar. It is full of small irregular 

 cavities, the sides of which are studded with a black mineral, 

 crystallized in regular prisms. This is schorl, regularly and per- 

 fectly developed. Numerous fissures or joints in the rock are 

 occupied with the same black mineral, which is always highly 

 crystallized. The rock of this bed is rejected as a building stone. 

 Near the top of the thick stratum, of which this is but a narrow 

 layer, the rock acquires a less altered aspect, being redder, softer, 

 and having less of the jaspery texture, but containing kernels of 

 pure epidote, well developed. This variety extends from where 

 it first shows itself, which is from the trap, about one hundred 

 and fifty feet in the thickness of the stratum, to a distance of a 

 fourth of a mile, where it is well exposed, being excavated at 

 another quarry. It gradually and regularly acquires the ordinary 

 unaltered features of the red sandstone ; but is even in the second 



