222 



Scientific Geology. 



in the sandstone, and divides the upper part of the formation from the 

 lower. Deerfield mountain, in its southern part, consists entirely of 

 the lower beds ; and the strata on the opposite side of the river be- 

 neath the greenstone, correspond in dip and general characters with 

 those of this mountain. Mount Toby is probably not far from 1000 

 feet above the river, and Deerfield mountain varies from 500 to 700. 

 These are much the most elevated points of the new red sandstone in 

 the valley of the Connecticut : and the enquiry immediately suggests 

 itself to the geologist, whether the formation was originally of this 

 height throughout its whole extent, and has been subsequently worn 

 away, except these ridges : or whether these have been raised so 

 much above the general level by a force acting beneath. The latter 

 supposition would seem most probable, were it not for the proof ex- 

 hibited by the above section, that no peculiar disturbing force has 

 acted on these mountains. Had that been the case, either their strata 

 would exhibit a different dip from the formation generally, or they 

 would not correspond on opposite sides of the river. It seems to me 

 perfectly obvious, after inspecting both these mountains, that almost 

 the only change their strata have undergone, was their original eleva- 

 tion about 10° to 15°, along with every other part of the formation. 

 And hence we are compelled to suppose, that the top of Mount Toby 

 exhibits nearly the original elevation of the whole formation. For 

 the idea that such insulated peaks and ridges, as those under consider- 

 ation, were deposited in the form we now find them, is perfectly absurd. 

 Further, we must suppose that the strata of Mount Toby originally 

 extended to the top of Deerfield mountain; as is represented by the 

 dotted line A C in the section. Nay, on this supposition, all the strata 

 of both mountains may have extended to the western side of the val- 

 ley, as at A. 



The immense period requisite to wear away such a mass of rock 

 as this theory supposes to have once occupied the whole valley of the 

 Connecticut, will seem to most minds the strongest objection against 

 its adoption : I mean supposing it to have been effected by such 

 causes as are operating at present. But this is not a solitary exam- 

 ple, in which geological phenomena indicate the operation of exist- 

 ing causes through periods of duration inconceivably long. We 

 may in this case, indeed, as I have already shown, suppose the occur- 

 rence of numerous deluges in the earlier periods of our globe. Still 

 even with the aid of such, catastrophes, the work must have been 

 immensely protracted. And why should we hesitate to admit the 



