42 Geology, &c. of the Connecticut. 
a dip as represented by the parallel lines. Let C D bea 
deposite of the coal formation lying upon the old red sand- 
stone, the strata of which have the same dip. Now, to 
an observer passing along the surface from A to D, the red 
sandstone, between A and C, appears to: lie upon the coal 
formation between C and D, whereas, the reverse is the 
fact. ‘This might apply to the rocks we are considering in 
Connecticut, were it not for what I think to be the fact, 
that there is a gradual passage of the old red sandstone in- 
to the coal formation. 
These, and some other circumstances, made me _suspi- 
cious, for a time, that this range of sandstone east of Con- 
necticut river, might not be the real old red sandstone, but 
a member of the coal formation ;—and it was not till I had 
traversed it the third time, that I felt entirely satisfied. 
But much of it certainly does not differ, at all as I could 
discern, from the old red sandstone on the western side of 
the river; and we find likewise the very same conglome- 
rate. The strata also, are of a similar thickness and dip, 
varying asto the form,from six inches to two or three 
feet; and as to the latter from 10° to 30°; usually, how- 
eyer, not more than 10°. This dip, in all the red sand- 
stone of the Connecticut, is below the eastern part of the 
horizon, with the single exception of a ledge that appears 
in the west street of Hatfield, where the dip is to the 
st. 
This rock is extensively quarried for the purpose of 
building, in almost every town along the river. Noble 
specimens may be seen in the vestibules of the churches in 
New-Haven. 
