The rivers of a country are a result and a measure of its climate. The generally large rainfall of the eastern half of North America is shown by the number and size of its streams, which, area for area, are longer and more frequent than those of the Old World, except on the eastern coast of Asia. The heaviest rainfall and the greatest average of streams is found about the Gulf of Mexico and the southern part of the Appalachian district. Hence, northerly, westerly, and northwesterly, the rainfall decreases in amount. The average of the region east of the Mississippi and south of the Laurentian Mountains is probably about fifty inches per annum, somewhere near one-third more than that of Europe. North America, despite the very dry district of the Cordilleras, has an average rainfall about as great as that of Europe, and probably rather greater than Asia; indeed its water-supply is rather greater than the average for lands situated so far from the equator. The rivers of America have been of very great importance in the settlement of the land. They afford more navigable waters than all the streams of Asia put together. Without the system of the Mississippi, which has more navigable waters than any river except the Amazons, it would not have been possible for America to have been brought under the control of colonies with such speed. The elevation of the surface of North America, at least of its more habitable portions, is very favorable to man. A large part of its fertile soils lie from five hundred to fifteen hundred feet above the sea. It has a larger part of its surface within the limits of height that are best suited to the uses of man than Asia, but less than Europe has. In considering the fitness of this continent for the use of European races, it will not do to overlook the mineral resources of the country. It may be stated in general terms that North America is richer in the mineral substances which have most contributed to the development of man than any other continent. The precious metals may be briefly dismissed. They occur constantly in two areas: the Cordilleran,—which, from Mexico, California, Nevada, New Mexico, and Colorado, has doubtless furnished more gold and silver than any other one mountain district,—and the Appalachian region, which has given about sixty million dollars to the world’s store of gold. The precious mineral resources of the Cordilleran region are probably greater than those of any other continent. They have already exercised a very great influence on the commercial and political history of the continent, and are likely to become of more importance as time goes on, for at least half a century to come.