No. 50.] 
469 
earth, that it seemed as if the ledge could be, at the most, but a few 
yards distant, at every place a stop was made. At the termination, 
there are no appearances that indicate the occurrence of a ledge ; such 
as projection above and abruptness below, or large rectangular masses 
lying near each other, with matched edges. But on the contrary, their 
surfaces, their roughness, their association and position display nothing 
more striking at the highest point, than the groups a few yards from 
the base of the hill. Upon the highest point none were found ; and it 
may be accounted for satisfactorily, upon the supposition that the frag 
ments in question were component parts of one of the lower layers of 
the coarse sandstone and conglomerate, whose outcrop, a little farther 
south, has already been mentioned. If this occupied the plot terminat- 
ing the ascent, it may all, in the agency of the great bodies of water 
which once lashed even the highest cliffs, have been easily wafted from 
the summit and distributed down the sides. 
The same rock occurs in several places along the Allegany, in huge 
fragments, and is seen to be of the most durable character, from the un- 
changed angularity of the masses, notwitstanding their long exposure to 
the action of the current. 
From examinations made in Pennsylvania, its true place is ascertain- 
ed to be in the lower part of the conglomerate. Could it be obtained 
south of Olean, without too much excavation, its value as a material for 
public works, would bring it immediately into demand. 
Nine miles below Olean, sandstone, slightly concretionary, has been 
quarried for the filling up of dams and other purposes. 
The Ischua stone quarries^ lying almost wholly in the town of Ma- 
chias, contain stone with which there are none other in the county to be 
compared, either for beauty when dressed, for readiness in getting out, 
or for durability. They are a coarse sandstone, disposed in massive, 
and in thin layers, of such thickness, that blocks for every desirable pur- 
pose, from heavy columns to thin flagging stone, may be procured with 
facility. There are, indeed, no stone, except some of the limestones 
north, in all western New-York, that equal them. 
Butler's quarries, three miles north of Franklinville, have been most 
extensively worked. The foundation walls of Irvine Hall, Ellicottville, 
were here procured. The quarries are in the visible outcrop, which 
extends for a considerable distance, with a gentle ascent behind, scarce- 
