It is a notable fact that the great river of rivers, which drains a larger territory than any other on the globe, the Amazon proper, has a fall of only two hundred and ten feet in a course of three thousand miles, and while it has a deep channel and a uniform current of three miles an hour for its whole length, it has no broken rapids. But in its many great affluents rapids are numerous, though not so famous as those found in other South American rivers. The river Orinoco, more remarkable in some respects than the Amazon, receives the waters of four hundred and thirty-six rivers, besides two thousand smaller streams. It is one thousand five hundred miles long, is navigable for seven hundred and eighty miles, and at Bolivar, two hundred and fifty miles from its mouth, it is four miles wide and three hundred and ninety feet deep. Its famous rapids of the Apure and Maypure were visited by Humboldt. At the latter, the river is two thousand eight hundred and forty yards wide, and plunges down an inclined plane about three miles long, making a fall equal to forty feet in vertical height. It is dotted with innumerable islands which furnish a striking contrast to the vast sheet of white water, presenting the singular appearance of an eruption of shrub-crowned rocks in a sea of foam. These islands, and its great width, constitute the peculiar characteristics of this chute. In the grandest of the South American rapids, those of the river Parana, a vast volume of water from a channel nearly two and a half miles in width is compressed into a gorge only sixty-six yards wide, through which the flood dashes down a slope of sixty degrees inclination and fifty-six feet perpendicular fall. Its roar--a perpetual monotone--is heard thirty miles away. Hardly less remarkable than the rapids of the South American rivers are those of the two great African rivers, the Nile and the Congo, or, as Mr. Stanley has re-christened the latter, the Livingstone. The Nile may be compared to a vast tree with its huge delta-roots in the Mediterranean, its boll extending up through a rainless desert nearly one thousand five hundred miles to meet its numerous branches which stretch up into the mountains of Abyssinia, and the vast basin south of the equator that contains the great lakes of Victoria N'yanzi and Albert N'yanzi. From these branches in each year, at a fixed season, are poured down the sediment-charged waters which irrigate and fertilize an immense valley that would otherwise be only a parched and desert waste.