194 
[Assembly 
gaey county, a few miles south-east of Friendship; in Cattarau- 
gus county, about five miles south of Olean, and on the road going 
from Olean to Ellicottville. In all these localities it occurs at ihe 
top of the hills; always limited as to extent, and of inconsiderable 
thickness. 
The locality nearest to Olean, is on the state road leading to the 
Pennsylvania line. There the appearance is exceedingly pictur- 
esque, representing a mass in ruins, some of the parts retaining 
their original horizontal position; a few present the appearance of 
huge centre tables, others are inclined at various angles, and some 
of the masses have found a lower level, having slided from the 
eminence on which they stood. The whole of the large frag- 
ments are covered with trees, whose vertical position strongly con- 
trasts with the varied and deranged state of the surface upon which 
they are placed. 
The conglomerate is about 20 feet in thickness, imperfectly di- 
vided into three masses; the upper one hard, the lower crumbly, 
from the slight cohesion of the pebbles. 
The appearance' just described of these rocks, has been caused 
by the difference in the solidity of its parts, conjoined with the ac- 
tion of water, and no doubt, at that remote period, which destroy- 
ed that continuity of surface which the rocks of the fourth district 
originally possessed, in common with all other sedimentary rocks. 
In the neighborhood of Ellicottville the conglomerate, probably 
the prolongation of the third mass met with on the road from Ole- 
an to that village, is equally an object of curiosity. This locality 
we did not visit, from the stormy state of the weather. We were 
told that the excavation is so regular as to exhibit the appearance 
of streets, and is known by the name of the City. 
Petroleum^ or Seneca Oil. On the dividing line of the counties 
of Cattaraugus and Allegany, at the foot of a small hill, surround- 
ed by forest and thicket, is the only oil spring in the fourth dis- 
trict. It has attained considerable celebrity; is situated in the In- 
dian reservation, of one mile square, and belongs to the Indians of 
Cattaraugus, living on the Allegany river. 
It is a dirty circular pool, about 18 feet in diameter, filled near- 
ly to its margin with foul water, having at the time we saw it, a 
small quantity of petroleum in clots, floating upon its surface. No 
