Since 1911 a considerable industry has been built up in the production of .gasoline , from casing-head gas—that is the gas which up between the casing and the tubing of an oil well, and collects in the casing head. This gas is known as gas, carrying a propor tion of the vapor of petroleum. The process is also applied to gas from gas wells if it carries as much As six pints of gasoline vapor to the 1,000 cubic feet. For the wetter gases the principle of compression is employed, with subsequent condensation. For the dryer gases the process is to pass the gas through a tank of heavy oil which absorbs the gasoline vapor, and the gasoline is afterward .distilled out. In 1915 there were in the United States 414 plants devoted to the production of gasoline from natural gas. The total recovery was 65,364,665 gallons, nearly half of which was gained in Oklahoma. The highest percentage was se cured from the gas of the Glenn Pool in Okla homa, which yielded eight gallons of gasoline per 1,000 cubic feet Liquid Natural Gas.— Natural gas may be liquefied by a pressure of 415 pounds at a tem perature of 36° F., or a pressure of 506 pounds at 48° F. Fifty cubic feet of the gas condense to one gallon of the liquid gas. The internal pressure in a cylinder of this liquid gas at 133° F. is but 755 pounds per square inch—only one-third the pressure of many liquefied gases. As an illuminant the vaporized liquid gas burns with a slightly yellower flame than the ordinary natural gas, and gives the best results with an inverted Welsbach mantle. It is en tirely effective in heating if a plentiful supply of air is provided. With oxygen in a blow pipe it gives a very hot flame. It has been used successfully to run an automobile, where provision is made to keep the valve warm; the vaporing, of the liquid gas produces a low tem perature in which the unprotected valve quick ly freezes up.
Early History.—Natural gas has been known since the earliest records of the human race as a curiosity. Perhaps the first historical record of the use of natural gas is that of the Apollo Oracle at Delphi in Greece, about 1,000 years before the Christian era. The Chinese are credited with the earliest practical application of this fuel at the wells at Tz-Lin Ching, western China, in the evaporation of salt brine.
The fire worshippers on the shores and is lands of the Caspian Sea, in the Baku region, Russia, and those of Punjab, India, have pre served a continuous flame in their temples, caused by a steady flow of natural gas for centuries. In after years it caused the deadly explosions in the deep coal mines in Europe and America, being known to the miners as fire damp, Its existence in the United States has been known since the first white men crossed the divide and explored the Ohio River watershed, as the Indians invariably conducted them to these natural vents, and, setting fire to them, viewed the effect with a semi-religious veneration. The discovery of vast reservoirs, up in the porous rocks of the United States and Canada, is of recentyears. The
artesian driller, searching for salt brine, knew of its presence since the first wells were drilled on the western flank of the Appalachian up lift; afterward the driller in search of petro leum encountered it, but by both of these early prospectors it was considered a source of danger and annoyance. It frequently caught fire, causing loss of life and destruction of the drilling outfit by a sudden outburst. It is on record that Washington in 1755 conveyed to the United States a small tract of land in Virginia containing a spring') fed by natural gas.
The earliest economic use of natural gas known in the United States occurred in. 1821, when it was used for the illumination of the village of Fredonia, N. Y. A well one and one-half inches in diameter was drilled to a depth of 27 feet near a noted gas spring and for many years supplied the village with 30 street lights.
In 1838 a water well dug at Findlay, Ohio, encountered such quantities of a foul smelling gas that it was abandoned for the original ob ject. It was subsequently covered up and the gas conveyed to a house near by and utilized for domestic fuel and lights for nearly 50 years.
About the year 1841, natural gas was found in a well near Charleston, W. Va., which also supplied salt brine, from which it was separated and for many years used as a fuel for making salt.
More or less natural gas was developed in the rush to find petroleum in the valley of Oil Creek in the winter of 1859 and the year fol lowing.
One of the first attempts to employ natural gas for fuel purposes was at a well drilled at Erie, Pa., in 1868, which was soon followed by many others; these wells were only 600 feet in depth and supplied from one to three fam ilies each. Titusville, Pa., enjoys the distinc tion of installing the first modern equipped nat ural gas plant, as well as the first well drilled for petroleum. This plant was constructed dur ing 1872, 13 years after the first oil well was drilled by Colonel Drake.
During 1873 natural gas was introduced into many of the villages of Butler and Venango counties for light and fuel, being supplied from wells drilled not far distant in prospecting for petroleum. In the year 1875 the first long pipe line (17 miles in length) was built; the pipe used was six and a quarter inches in diameter, supplying the natural gas produced from the Harvey well at Larden Mills, in Butler County, Pa., to a large manufacturing plant known as the Etna Iron Company on the Allegheny River, a few miles above Pittsburgh. In the 10 years that followed slow progress was made in the actual use of the known gas wells; many were utterly ruined by pulling the casing and allow ing the inflow of muddy water, which gradually sealed up the rock and prevented the flow; this was after a struggle for years. The gas from other wells was allowed to escape into the air for years. There seemed to be an uncertainty in the minds of all, as to the lasting supply of this natural product.