PETROLEUM AND NATURAL GAS. 55 
in the Washington field, including North* and South Strabane town- 
ships and the borough of Washington, varies from 1,817 to 1,930 feet; 
in the Amity and Former fields, from 1,905 to 1,941 feet; in the Zol- 
larsville field, from 1,940 to 2,057 feet. The bottom of the Fifty-foot 
sand is usually not over 50 feet above the top of the group of red shales 
which are considered the Catskill beds at the top of the Devonian sys- 
tem. This sand is therefore considered as most probably the lowest 
sand in the Carboniferous system. (See discussion on p. 28.) 
The distribution of oil and gas in the Fifty-foot sand shows a fair 
agreement with their occurrence in the Gantz, as would naturally be 
the case where two sands in close association are in places combined. 
In the Washington field the Fifty-foot sand has furnished many good 
wells, including some of the great producers. Many of the wells 
which found oil in both the Gantz and Fifty-foot obtained the greater 
proportion from the lower of the two sands. The Fonner field has 
also furnished oil wells from this sand. In this field the Fifty -foot and 
Gantz sands are generally united. 
The Fifty-foot sand has not yet produced a great amount of gas, 
but in Somerset Township several wells have obtained gas in this sand 
and it has occasionally been found at this horizon in the Zollarsville 
field. In the Washington field a large proportion of the oil wells, in- 
cluding most of the enormous producers, have long since ceased to be 
productive and have been- abandoned. 
Gordon Stray sand. — Above the Gordon sand and near the top of the 
red beds a sand is sometimes reported by the name of Gordon Stray. 
Sands at about this horizon are also frequently called Butler Thirty- 
foot, Nineveh Thirty-foot, or simply Thirty-foot or Stray. There is 
considerable doubt whether this horizon should properly be included 
in the Chemung formation or in the Pocono, but as in a few cases 
thin red shales have been reported just above it, the Gordon Stray 
sand is here considered one of the lentils in the Catskill member of the 
Chemung. 
Although not classed as one of the productive sands, the Gordon 
Stray is frequently known to produce gas, and in the borough of 
Washington gas has from time to time been found in it. One of these 
gas wells was that of Matthew Linn, in which the rock pressure 
amounted to over 600 pounds per square inch. 
Gordon sand. — In the vicinity of Washington this is one of the prin- 
cipal oil sands, and occurs near the top of the Venango oil group 
and of the Third sand horizon of Oil Creek. The name " Gordon" 
originated from the Gordon farm near Washington, where the sand 
was first pierced by the drill in August, 1885. In the Gantz well this 
sand occurs 245 feet below the top of the Gantz sand, and in other 
wells in that vicinity the interval varies from 240 to 300 feet. It is 
usually about the first conspicuous sand below the top of the Catskill 
