Thus Babylon was conquered and robbed by Rome, and Rome, after a long heyday of prosperity, yielded to Constantinople, while Constantinople lost her supremacy to Venice, Genoa, and North Italy, following the sack of Constantinople by the Venetians in 1202 A.D. The Fairs of Champaign in France, and the cities of the Rhine and Antwerp were the glory of the Middle Ages, but these great markets faded when the discovery of the long sea voyage to India threw the route by the Red Sea and Cairo into eccentricity, and caused Spain and Portugal to bloom. Spain’s prosperity did not, however, last long. England used war during the sixteenth century as an economic weapon, pretty easily conquering. And since the opening of the Industrial Revolution, at least, London, with the exception of the few years when England suffered from the American revolt of 1776, has assumed steadily more the aspect of the great international centre of exchanges, until with Waterloo her supremacy remained unchallenged. It was this brilliant achievement of London, won chiefly by arms, which more than any other cause impelled Germany to try her fortunes by war rather than by the methods of peace. Nor was the German calculation of chances unreasonable or unwarranted. For upwards of two centuries Germany had found war the most profitable of all her economic ventures; especially had she found the French war of 1870 a most lucrative speculation. And she felt unbounded confidence that she could win as easy a triumph with her army, over the French, in the twentieth as in the nineteenth century. But, could she penetrate to Paris and at the same time occupy the littoral of the Channel and Antwerp, she was persuaded that she could do to the commerce of England what England had once done to the commerce of Spain, and that Hamburg and Berlin would supplant London. And this calculation might have proved sound had it not been for her oversight in ignoring one essential factor in the problem. Ever since North America was colonized by the English, that portion of the continent which is now comprised by the Republic of the United States, had formed a part of the British economic system, even when the two fragments of that system were competing in war, as has occurred more than once. And as America has waxed great and rich these relations have grown closer, until of recent years it has become hard to determine whether the centre of gravity of this vast capitalistic mass lay to the east or to the west of the Atlantic. One fact, however, from before the outset of this war had been manifest, and that was that the currents of movement flowed with more power from America to England than from America to Germany. And this had from before the outbreak of hostilities affected the relations of the parties. Should Germany prevail in her contest with England, the result would certainly be to draw the centre of exchanges to the eastward, and thereby to throw the