In the so-called baser, yet really more precious, metals this continent is even more fortunate. The supplies in the most important metal, iron, are very great,—certainly greater than in Europe. This metal is distributed with much uniformity over the country, there being scarcely a State except Florida that cannot claim some share of this metal. Especially rich in deposits of this metal are the States which share the Appalachian district, and the States of Missouri and Michigan. The Rocky Mountains also abound in iron ores, which there often contain a certain proportion of the precious metals; so that it is possible that the exploitation of the two metals may in time be carried on there together. There is probably no other continent that contains as large a share of iron,—the most important metal for the uses of man. The other less used, but still commercially important, metals,—zinc, lead, and copper,—are found in considerable abundance in the Appalachian, the Laurentian, and the Cordilleran regions, especially in the last-named district. The only metal that is rarely found in North America, never yet in quantities of economic importance, is tin. Some specimens of bronze implements have been found in Mexico and Peru. They seem to afford the only evidence that the aboriginal peoples knew how to smelt any metals. Though the natives in the more northern districts used copper, they never discovered the art of smelting it. Considering the useful metals as a whole, North America is proportionally richer than any other country that is well known to us. The most considerable of the resources that the rocks of America offer, are found in the deposits of coal which they contain. These deposits are of vast extent, and are excellently fitted for the various uses of this fuel. While the other mineral resources of the country are most abundant in the region of the Cordilleras, the best of these deposits of coal are accumulated in and about the Appalachian district. At least nine tenths of the coal of America lies to the east of the Mississippi River. New England, New York, South Carolina, Florida, Mississippi, and Louisiana are the only States that are practically without coal; and even in New England, Rhode Island and the neighboring parts of Massachusetts have promising but essentially undeveloped fields. In the Cordilleran district coal deposits of small area occur; but the material is generally of poor quality, and is not likely to have a great utility. As a whole, the resources in the way of subterranean fuel are far richer on this continent than in Europe. The area of coal-bearing rocks is at least eight times as great, and the deposits are much better disposed for working. No other continent save Asia is likely to develop anything like these coal resources; in China the coal area seems much larger than that of North America, but the richness of the field has not yet been fully proven: it is, however, undoubtedly great.