PETROLEUM AND NATURAL GAS. 51 
known as the Mountain sand. In Washington County the Big Injun 
is sometimes called the Manifold sand, for the reason that in a well on 
the Manifold farm (180), near Washington, oil was found in it. 
The Big Injun sand is everywhere present and can be easily recog- 
nized by the drillers. In thickness it varies from 250 to over 350 feet. 
In many places it contains two or three coarse, porous, and, in some 
cases, pebbly layers, filled with oil, gas, or salt water. These are what 
the drillers call "pay" streaks. An interesting feature of the sand is 
a shaly break, which is frequently encountered about one-third of the 
distance from the top. This break locally amounts to as much as 20 
feet in thickness. It has been recorded especially in the J. L. Thomp- 
son wells and in a well in Morris Township. 
The interval from the Pittsburg coal to the top of the Big Injun 
sand varies from 1,115 feet in the Culbertson well at Washington, to 
1,292 feet in the Burkehammer well near Deemston. In general, it 
is greater toward the southeast, owing largely to the increased thickness 
of the Mauch Chunk in that direction. (See pp. 27, 530 In the vicinity 
of Washington and in North and South Strabane townships the inter- 
val is usually between 1,130 and 1,160 feet. In several wells in North 
Franklin Township it is reported as 1,200 to 1,225 feet, but to the 
south, along the western edge of the quadrangle, it diminishes to about 
1,140 to 1,190 feet. One record reports as small an interval as 1,075 
feet, but the accuracy of this is doubtful. 
In the Zollarsville field a large number of measurements of this 
interval are at hand, and these show a good agreement. Near Zol- 
larsville it varies only between 1,233 and 1,257 feet; near and west of 
Deemston between 1,200 and 1,286 feet, and southwest of Beallsville 
between 1,210 and 1,245 feet. Only a few records from Somerset 
and Nottingham townships are at hand, but in these the figures 
are 1,196 feet near Ellsworth, 1,205 feet northeast of Vanceville, 1,217 
feet north of Bentleyville, 1,156 feet near Kammerer, 1,188 feet mid- 
way between Kammerer and Munntown, and about 1,200 feet near 
Finleyville. 
In general, the Big Injun sand is unproductive, but in several places 
it has locally produced oil.. The most important instance of this 
kind was in the Manifold No. 1 well, drilled in 1886, on the Manifold 
farm near Washington. This is one of the most remarkable wells in 
the Washington field on account of its great yield of oil, its long- 
continued production, and the lack of interference from neigh- 
boring wells. Although located in a district which was thoroughly 
perforated by holes, none of the neighboring wells harmed it, and in 
none of them, with two or three exceptions, was oil found at this 
horizon. Of the other wells which produced oil at this horizon, the 
most important is the Willetts No. 11 close by. The Manifold well 
flowed about 700 barrels per day. A little gas is reported from this 
