390 AMERICA regions probably exceeding those of all the rest of the globe. Lead is found in various parts, the main locality, probably the most produc- tive in the world, being in Illinois, Iowa, Mis- souri, and Wisconsin. Quicksilver has hitherto been found chiefly in Mexico and California, where the mines equal in productiveness those of Austria. Zinc has been found only within a limited area, mainly in New Jersey and Penn- sylvania. Tin is the only valuable metal which does not occur in large quantities. The coal fields of North America comprise more than seven eighths of all known to exist. Those already explored exceed the entire area of Great Britain. Salt is widely diffused, the principal suline springs being in New York, Virginia, and Michigan. Petroleum, which may properly be classed among mineral sub- stances, abounds within a comparatively lim- ited area, the central point being in north- ern Pennsylvania, thence extending northward and westward. Politically North America is divided into British America, the United States, and Mexico. British America occupies tha whole northern half, with the exception of Alaska, the extreme northwestern angle, for- merly Russian America, but now by purchase belonging to the United States. It is bounded N. by the Arctic ocean, E. by Davis strait and the Atlantic, S. by the United States, and W. by Alaska and the Pacific (where its shore line is very narrow, only about 350 m.). Its entire area is about 3,500,000 sq. m. ; but with the exception of a border on the St. Lawrence and the lakes, and a very narrow strip on the Red river, and a portion on the Pacific, the whole of British America lies north of the line of cultivation. The popula- tion is 4,455,000, of which the larger part are of European descent. Nearly all of habitable British America is now consolidated as the Dominion of Canada. The United States oc- cupy the central part of North America, from the Atlantic to the Pacific. They are mainly bounded N. by British America (Alaska occu- pying an isolated position), S. by Mexico, E. by the Atlantic, and W. by the Pacific. The total area, including Alaska (580,107 sq. m.), is about 3,600,000 sq. in. The population by the census of 1870 is 88,558,371, of whom 33,589,377 are white, 4,880,009 colored, 63,254 Chinese, and 25,731 settled Indians. Mexico is bounded N. by the United States, E. by the gulf of Mexico and the Caribbean sea, W. by the Pacific, and S. by Central America. It has an area of near- ly 800,000 sq. m., and a population estimated in 1868 at 9,173,052, of whom more than half are set down as Indians, and only about 1,000,000 whites, the remainder being of mixed blood and negroes. II. CENTRAL AMERICA, occupy- ing the greater part oft the isthmus of Darien, comprises the states of Guatemala, San Salva- dor, Honduras, Nicaragua, and Costa Rica, which since 1863 have formed a loose political union, under the name of States of Central America. They contain about 175,000 sq. m., with a population estimated in 1865 at 2,665,- 000, of whom 1,500,000 are Indians, 1,000,000 of mixed blood, 130,000 whites, and 35,000 blacks. Central America lies wholly within the tropics; but many parts of it are sufficiently elevated to give a temperate climate. III. SOUTH AMERICA extends from Cape Gallinas, lat. 12 30' N., to Cape Horn, lat. 55 59' S., its extreme length being 4,550 m. The distin- guishing physical feature is the chain of the An- des or Cordilleras, which borders the whole W. coast, at a distance of from 50 to 100 m. from the shore, gradually sinking at the southern ex- tremity to the level of the ocean, a few sum- mits appearing as rocky islands. From lat. 22 S. northward the range widens, spreading into a series of ridges generally parallel, the westernmost ridge, almost continuous, being the Andes proper, or Cordillera of the coast. The main line follows, or rather constitutes the isthmus of Panama, an offshoot striking north- easterly to the Caribbean sea. This last is divided into several parallel ridges, through the intervening valleys of which the Atrato and the Magdalena flow northward into the Carib- bean. The general chain is nowhere broken through, and thus forms a complete separation between the waters which flow into the Pacific and those which full into the Atlantic. On the Pacific side there is no considerable river. From the eastern base of the Andes several ranges of highlands divide the whole country into a number of shallow basins. Topographi- cally South America is divided into seven dis- tinct regions : 1. The shore of the Pacific, 50 to 100m. in breadth, the extremities of which are fertile, the centre being a sandy desert. 2. The elevated table lands lying between the folds of the main Andes and the other Cordilleras ; the chief of these are those of Quito and Bogota. 8. The basin of the Orinoco, a series of llanos, or level plains thinly wooded, but covered du- ring the wet season with late herbage, which withers in the dry season, when the heat is in- tense. 4. The great basin of the Amazon, cov- ering about 2,000,000 sq. m., for the most part densely wooded and thinly peopled. 5. The basin of the Rio de la Plata, a series of plains, known as pampas, the river banks clothed with forests, and the interior covered with luxuriant grass, which supports immense herds of cattle, millions of which are annually slaughtered for their hides. The cattle here probably excel in number those of all the rest of the globe. 6. The mountainous region of E. and S. Brazil, extending from the Atlantic to the interior, where it almost imperceptibly joins with the two former regions. 7. Patagonia, occupying the whole breadth of the continent from about lat. 40 S. to Cape Horn. This region is almost wholly unexplored. The Argentine Confedera- tion claims dominion over a great part of it ; but practically it is inhabited only by savages, with scarcely a trace of even a tribal govern- ment. About three fourths of South America lie geographically within the tropics ; but the
