[Illustration: World Production in 1918.] Finally, the earliest settlers found oil in America, or, to be more exact, recognized the wells which had already been dug by the Indians. But it was only in the middle of the nineteenth century that the real importance of the oil-fields scattered over the globe began to be realized. While France about 1840 made the first trial use of shale oil, and Germany in 1853 invented the oil lamp, later perfected by Laydaw of Edinburgh, "the bold and inventive spirit of Young America undeterred by a series of fruitless experiments, set itself to discover the first springs of the precious liquid in Pennsylvania." In 1858 Colonel Edward Drake, while boring a salt-water well near Tytusville, was nearly engulfed with his workmen in a jet of oily liquid, the spring of which was apparently inexhaustible, and continued to furnish several thousand litres a day. It was subsequently discovered that this liquid after a very simple process of purification, would burn with a brilliant light. The "oil fever" then seized all America and myriads of searchers rushed into the valleys of the Alleghanies in Pennsylvania. The oil industry was created. For a long time America was the only country producing the precious oil; forty years ago she still furnished two-thirds of the world's supplies. But although the oil-fields of the Alleghanies and of Ohio were developed rapidly, they have been far surpassed by the enormous deposits of Baku. In 1898 Russia outdistanced the United States, and kept the first place until 1902, when America recovered it after a great struggle, thanks to the new oil basins of Texas, California, and the Mid-Continent, and above all those of Kansas and Oklahoma, with its famous "Glen Pool," which in 1908 produced the fantastic figure of 50,000 barrels _a day_.