s. One of these was estimated as yielding 30,000,000 cubic feet
in 24 hours. This district lies to the northeast of Pittsburg, running
southward from it toward the Pennsylvania Railroad. Gas has been found
upon a belt averaging about half a mile in width for a distance of
between four and five miles. Beyond that again we reach a point where
salt water flows into the wells and drowns the gas. Several wells have
been bored upon this belt near the Pennsylvania Railroad, and have been
found useless from this cause. Geologists tell us that in this region a
depression of 600 feet occurs in the strata, but how far the fault
extends has not yet been ascertained. Wells will no doubt soon be sunk
southward of the Pennsylvania Railroad upon this half-mile belt. Swinging
round toward the southwest, and about twenty miles from the city, we
reach the gas fields of Washington county. The wells so far struck do not
appear to be as strong as those of the Murraysville district, but it is
possible that wells equally productive may be found there hereafter.
There are now four wells yielding gas in the district, and others are
being drilled. Passing still further to the west, we reach another gas
territory, from which manufacturing works in Beaver Falls and Rochester,
some twenty-eight miles west of Pittsburg, receive their supply.
Proceeding with the circle we are drawing in imagination around
Pittsburg, we pass from the west to the southwest without finding gas in
any considerable quantity, until we reach the Butler gas field,
equidistant from Pittsburg on the northwest, with Washington county wells
on the southwest. Proceeding now from the Butler field to the Allegheny
River, we reach the Tarentum district, still about twenty miles from
Pittsburg, which is supplying a considerable portion of the gas used.
Drawing thus a circle around Pittsburg, with a radius of fifteen to
twenty miles, we find four distinct gas-producing districts. In the city
of Pittsburg itself several wells have been bored; but the fault before
mentioned seems to extend toward the center of the circle, as salt water
has rushed in and rendered these wells wholly unproductive, though gas
was found in all of them.

I spent a few days very pleasantly last autumn driving with some friends
to the two principal fields, the Murraysville and the Washington county.
In the former district the gas rushes with such velocity through a 6-inch
pipe, extending perhaps 20 feet above the