Russia has never been able to retrieve her position. Her production, which in 1901 was 50 per cent. of that of the whole world, was not more than 20 per cent. two years before the War, and in 1918 had fallen to 7.86 per cent. The cause is chiefly the diminution of production of the "black region" of Baku, in the peninsula of Apsheron, which juts out into the Caspian Sea and is connected with the open seas by a railway and by a pipe 800 kilometres long, through which the annual flow of oil towards Europe before the great world catastrophe amounted to 400,000 tons. In five years the average yield of the wells diminished by 40 per cent., while the mean depth of the borings was increased by 25 per cent. It was necessary to dig more and more deeply to find less and less oil. The old oil-fields of Baku were nearing exhaustion. Now they alone furnished four-fifths of the production of Russia. That is why, in 1918, Russia lost the second place, which she had held so long, to her young rival Mexico. It is true that the two revolutions which she had to undergo in this quarter century helped the process considerably. The revolution of 1905 caused the bloody disturbances of the Caucasus: the finest factories were burnt and numerous wells destroyed. Great unrest continued incessantly in this region until the triumph of Lenin. But there are still in Russia oil-fields of very considerable extent, scarcely touched before 1914, which the world cannot afford to dispense with.[6] The United States, Russia, Mexico, Rumania, these were, in order of importance, the four chief oil-producing countries before the War. Rumania shares with America the distinction of being the first country in which rock-oil was extracted. The same year in which Colonel Drake made his experiments at Tytusville 250 tons were extracted from a well by hand-pumping: the oil was only just below the surface. Since then Rumanian production has continually increased. It was 500,000 tons when the region of Moreni, one of the richest in the world, was discovered. Foreign capital flowed in immediately, and Rumanian production reached its highest point in 1913 with 2 million tons. The War gave it an appreciable setback; at the present time it does not come to more than half this figure.[7] [Illustration: Pre-war production of oil in Mexico, Rumania, the Dutch Indies and Galicia.] Although the production of Rumania, hampered by the lack of electricity which hinders the borings, has recovered with difficulty, that of Mexico, often a prey to civil war, has known no pause in its incredible progress. In ten years it has passed from 3 to 160 million barrels, carrying its share in world production from 1 per cent. to 23 per cent. The figures are worth quoting:--