Suddenly, in two short years, all was changed. In 1492 Columbus discovered America, and in 1494 Vasco da Gama, doubling Africa, found the way to India. The effect of these discoveries cannot be overestimated. We can hardly conceive how our mediæval forefathers viewed the ocean. To them the ocean was a numbing, constricting presence; the abode of darkness and horror. No wonder mediæval Europe was static, since it faced on ruthless, aggressive Asia, and backed on nowhere. Then, in the twinkling of an eye, dead-end Europe became mistress of the ocean--and thereby mistress of the world. No such strategical opportunity had, in fact, ever been vouchsafed. From classic times down to the end of the fifteenth century, white Europe had confronted only the most martial and enterprising of Asiatics. With such peoples war and trade had alike to be conducted on practically equal terms, and by frontal assault no decisive victory could be won. But, after the great discoveries, the white man could flank his old opponents. Whole new worlds peopled by primitive races were unmasked, where the white man's weapons made victory certain, and whence he could draw stores of wealth to quicken his home life and initiate a progress that would soon place him immeasurably above his once-dreaded assailants. And the white man proved worthy of his opportunity. His inherent racial aptitudes had been stimulated by his past. The hard conditions of mediæval life had disciplined him to adversity and had weeded him by natural selection. The hammer of Asiatic invasion, clanging for a thousand years on the brown-yellow anvil, had tempered the iron of Europe into the finest steel. The white man could think, could create, could fight superlatively well. No wonder that redskins and negroes feared and adored him as a god, while the somnolent races of the Farther East, stunned by this strange apparition rising from the pathless ocean, offered no effective opposition. Thus began the swarming of the whites, like bees from the hive, to the uttermost ends of the earth. And, in return, Europe was quickened to intenser vitality. Goods, tools, ideas, men: all were produced at an unprecedented rate. So, by action and reaction, white progress grew by leaps and bounds. The Spanish and Portuguese pioneers presently showed signs of lassitude, but the northern nations--even more vigorous and audacious--instantly sprang to the front and carried forward the proud oriflamme of white expansion and world-dominion. For four hundred years the pace never slackened, and at the close of the nineteenth century the white man stood the indubitable master of the world.