age of
immense quantities of oil, that is scattered on the ground and runs into
the creek. So great is this waste at times, that the oil is gathered in
quantities on the surface of the Alleghany for a distance of eight or
ten miles below the mouth of Oil Creek, in the eddies, and along the
still water of the shore, and is distinctly perceptible at Pittsburg, a
distance of one hundred and forty miles from the wells.

Notwithstanding these wells are confined to a very narrow valley, and in
many instances in very close proximity, it is very rare that they
interfere with each other. In fact cases are known where two wells have
been bored within forty feet of each other, with the discovery of oil at
different depths, and even of different qualities, as regards color and
gravity. In some instances the well has all the characteristics of an
intermittent spring. One in particular may be specified for the
regularity of its operations. It would remain quiescent for about
fifteen minutes, when there would be heard the sound as of fearful
agitation far down in its depths. This rumbling and strife would then
appear to approach the surface for a few moments, when the petroleum
would rush forth from the orifice, mingled with gas and foam, almost
with the fury of a round shot from a rifled cannon. This furious flow
would continue for fifteen or twenty minutes, when it would suddenly
subside, and all would be peace again. This alternate rest and motion
would continue with great regularity day and night, yielding perhaps one
hundred and fifty barrels per day. In other instances, there are
interruptions of days and even weeks, when the flow will be continued as
before. In others still, the yield is steady and uninterrupted, yielding
with unvarying regularity from week to week.

The oil region of Venango County, as far as has been explored, is
confined to the creek and river bottoms. In connection with wells that
have been opened, there is a superincumbent stratum of earth, varying
from ten to sixty feet in thickness: underlying this is a stratum of
argillaceous shale, generally about one hundred and eighty feet in
thickness, and then a stratum of white sandstone. Sometimes this
sandstone is intermingled with red, presenting a ruddy appearance as the
sand is withdrawn from the well in the process of boring.

Occasionally in passing through the shale, small fissures in the rock
are passed through, with circumstances indicating the presenc