subject, mention should be made of the gas which so generally accompanies the oil. It is often met with in the oil-regions when no oil is struck, producing "gas-wells;" and is also met with where no oil, or very little, is found, on the borders of the oil-districts. Many private residences and manufacturing establishments are heated and lighted by this gas; Fredonia, New York, has been lighted with it for years. The Newton gas-well, five miles south of Titusville, Pennsylvania, is 786 feet deep, and yielded 4,000,000 cubic feet per day, supplying light and fuel to a great number of dwellings and manufactories in Titusville. A rolling-mill near Pittsburg is run by gas brought from Butler County, a distance of about nineteen miles, and when it is not needed the gas is lighted, furnishing a jet of flame seventy feet high, which, with another jet from a neighboring mill, furnishes a grand spectacle at night.
This gas is the cause of spouting-wells. If a well is sunk into the top of a fissure containing oil and gas, the gas will first escape, and then the oil must be pumped out; but, if the well strikes in the oil, the pressure of the gas would first drive out the oil. If water also was present and the well struck the bottom of the fissure the heavier water would first escape, then the oil, and then the gas. Such a well, after standing a while would again yield oil on pumping, then perhaps water only, or water and oil, until it had had another rest. If the supply of gas is kept up by an open crevice, the well may continue to flow for some time. The pressure of neighboring water may also cause the oil to flow from a well. Generally the pumping-wells are pretty constant, although when a number of wells are bored near together they interfere with each other, and sometimes water poured down one well will appear in another, and this method has been pursued to bring rival well-owners to terms.
A few words may here be said about drilling wells and transporting the oil. The wells are drilled by means of drilling-tools like those used in sinking artesian wells, which are suspended by a cable, and operated by small steam-engines. The well is lined with wrought-iron tubing, screwed together in sections, and, to prevent water from flowing down the outside of the lining into the well, a water-packer is used, which is essentially a circular piece of leather with the edges cut and turned upward, so that the whole forms a cup about the tube, which is pressed tightly against the sides of the well by the weight of the column of water. It is much better than the old flaxseed bag. The oil is conveyed from the oil-district to the refineries and shipping-stations by means of wrought-iron pipes, two to four inches in diameter, which form a network throughout the entire country, and have an aggregate length of nearly 2,000 miles. One company carries the oil thirty-seven miles, in this way, from Butler County to the vicinity of Pittsburg.
Refining and Uses of Petroleum.—Crude petroleum contains
