It appears a convenient, though doubtless very rough, way of prefacing this subject to say that the huge colonizing movements of the eighteenth century were brought to a pause by the American Revolution, which deprived Great Britain of her richest colonies, succeeded, as that almost immediately was, by the French Revolution and the devastating wars of the republic and of Napoleon, which forced the attention of Europe to withdraw from external allurements and to concentrate upon its own internal affairs. The purchase of Louisiana by the United States at the opening of the current century emphasized this conclusion; for it practically eliminated the continent of North America from the catalogue of wild territories available for foreign settlement. Within a decade this was succeeded by the revolt of the Spanish colonies, followed later by the pronouncements of President Monroe and of Mr. Canning, which assured their independence by preventing European interference. The firmness with which the position of the former statesman has been maintained ever since by the great body of the people of the United States, and the developments his doctrine afterwards received, have removed the Spanish-American countries equally from all probable chance of further European colonization, in the political sense of the word. Thus the century opened. Men's energies still sought scope beyond the sea, doubtless; not, however, in the main, for the founding of new colonies, but for utilizing ground already in political occupation. Even this, however, was subsidiary. The great work of the nineteenth century, from nearly its beginning to nearly its close, has been in the recognition and study of the forces of nature, and the application of them to the purposes of mechanical and economical advance. The means thus placed in men's hands, so startling when first invented, so familiar for the most part to us now, were devoted necessarily, first, to the development of the resources of each country. Everywhere there was a fresh field; for hitherto it had been nowhere possible to man fully to utilize the gifts of nature. Energies everywhere turned inward, for there, in every region, was more than enough to do. Naturally, therefore, such a period has been in the main one of peace. There have been great wars, certainly; but, nevertheless, external peace has been the general characteristic of that period of development, during which men have been occupied in revolutionizing the face of their own countries by means of the new powers at their disposal.