ward to the Lake St. Clair, and thence by the Detroit River into Lake Erie. The Niagara River connects the latter with Lake Ontario.

Niagara Falls

The greatest natural wonder of the region of the Great Lakes are the Falls of Niagara, which were discovered by Pere Hennepin in 1678. The Niagara River, which connects Lake Erie and Ontario, and forms the boundary between the United States and Canada, has a course nearly due north for 36 miles, of which 22 are above and 14 below the Falls.

Just above the Falls the river encircles a large island, known as Grand Island, its course thus far being gentle. Presently, however, it begins to feel the influence of the coming leap, and, sweeping along more tumultuously, soon breaks into furious rapids. Reaching the head of Goat Island, it separates into two branches, that on the American side rushing straight forward to the brink in a mass 1000 feet broad and shooting over into the gulf below. That on the Canadian side of Goat Island sweeps around and plunges over a cliff in the form of a horseshoe (whence the name of the Fall), the two parts of the river meeting at the foot of the Fall.

The height of the American Fall is 180 feet; that of the Horseshoe Fall is slightly less, owing to the smaller height of the crest, being 173 feet.

Like most waterfalls, Niagara is working backwards up stream. It is retreating towards Lake Erie, which it will some day reach, when that lake will be lowered to the level of Ontario.

"The great cataract is the embodiment of power. In every second, unceasingly, seven thousand tons of water

[graphic]
[graphic]

ing stream, forced with growing speed against the air, parts into rhythmic jets which burst and spread till all the green is lost in a white cloud of spray, on which the rainbow floats. Its charms are the theme of many a gifted bard and artist, but the fascination of its evervaried yet continuous motion, and the awe that waxes rather than wanes with familiarity, are not to be felt at second-hand; and so the world, in long procession, goes to see."—Niagara Falls and their History, by G. K. Gilbert; National Geographic Monographs.

The Cordillera

The western part of the United States is a great plateau, crested by the numerous ranges which collectively compose the Cordillera. Occupying practically the entire width of Mexico, from ocean to ocean, this plateau enters the United States with a great breadth, extending with its long eastern slope from, say, the 100th meridian westward nearly to the Pacific coast. Its flat crest is at the continental water-parting, in western New Mexico, where it is 4000 to 4500 feet above the sea. As we follow it northward, we find its eastern limits still less clearly defined. The western boundary is, however, sharply limited by the Sierra Nevada and the Cascade Range, which sweep somewhat to the westward and thus increase its breadth. The great streams of this region follow the general slopes of this plateau, with little regard to the course of the ranges which cap it, as though their courses were established before the mountains rose. The continental divide or water-parting, which separates the rivers flowing to the Atlantic from those flowing to the Pacific, is a line, following in general, from south to north, the highest part of the plateau, and the courses of the great rivers indicate broad depressions in the plateau.

The continental divide enters the country from the south with an altitude of 4000 to 4500 feet. Thence it increases in altitude northward, and reaches a maximum in Colorado, where it is nearly 10,000 feet above the sea. Passing north-westward through Wyoming with a height of 7000 to 8000 feet, it drops to 4000 feet in crossing the Canadian boundary.

Eastward from its crest this great underlying plateau slopes gently and gradually to the eastward down the great incline of the plains.

On the west its features are more complex. The Colorado River of the west heads near the crest-line of the plateau, and pursuing a general course somewhat west of south, enters the Gulf of California beyond the southern boundary of the country. This great river, with its long tributaries from either side, marks a general depression in the surface of the plateau. The rise on the west from this depression separates the basin of the Colorado from the Great Basin, a region extending from the Wasatch Range in Utah to the Sierra Nevada in eastern California, and from southern Oregon to southern Nevada, the waters of which have no communication with either ocean, and consequently no outlet save evaporation. Near the middle of this basin there is a well-marked rise of the general level on a meridional line, east and west of which there is a depression. The easternmost of these depressions is occupied by Great Salt Lake; the westernmost by the lakes and sinks of western Nevada. In the northern part of the country the plateau appears to have a uniform slope westward from the crest.

The ranges which crown this plateau are many and complex, ranging widely in height, in orographic form,

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