Page:Popular Science Monthly Volume 15.djvu/221

Rh of nature, and which exists in large quantities in various parts of the world. It is, comparatively speaking, a very recent discovery. The first well was sunk in Pennsylvania in 1858. The first "flowing well," or bore hole from which the rock oil flows naturally, dates in 1861. From that date the annual production has increased with marvelous rapidity. In 1878 it was computed that several hundred million gallons were annually raised, although only about one-half per cent, of the 2,000 square miles of area in which the mineral oil is to be found was then worked. The oil is also known to exist in Virginia, in Ohio, in Kentucky, in California, in Canada, in South America, in China, in Japan, in Java, on the north coast of Africa, in Italy, France, Austria, Wallachia, Turkey, and Russia. There is every reason to suppose that an unfailing supply might be obtained by boring in the valley of the Jordan, in which rapid stream masses of bitumen are often found borne down to the salt waters of the Dead Sea. On the shores of the Caspian it is found in such abundance that it is used as fuel for steamers. At Cheeriley, about twenty-five miles to the west of Kertch, it is stated by Mr. Ross that there are five wells owned by an Englishman, two of which produce about one hundred and thirty-five barrels of petroleum daily. Bitumen and bituminous shales producing oil are to be found in every country of Europe, and there is good reason to suppose that the existing stores of the liquid mineral are no less ample than those of the solid beds of coal.

As to cost, the crude petroleum oil is sold at the mouth of the wells, in Pennsylvania, at from 10s. to 15s. per ton, or from d. to d. per gallon. The refined petroleum at New York is worth about 6d. per gallon, but half of this is the price of the casks or other vessels that contain it. If a large and steady demand were to set up, it would be easy to construct ships of which the hold should be composed of a series of air-tight compartments, in wrought iron, into which the oil might be turned directly by means of mains, like gas or water mains in our cities, and from which it might be pumped on its arrival in the Thames or in the Mersey. The cost of the delivery of this liquid fuel may thus be expected to be, hereafter, less per ton than that of coal. It only needs the first expense, that of sinking the shaft. It will then mine itself, raise itself, carry itself, and may be made to load itself on shipboard. As to the cost of the process of refinement, we are without adequate information. But, in the event of a brisk demand for the refined oil, there can be little doubt that the usual course of manufacturing industry would be followed, and that an economical method would be applied.

It is thus of interest to compare the respective properties of coal, coal-gas, and petroleum, both as regards their lighting and their heating capacities, as far as the present state of definite scientific information attainable will allow us to do so.