THE PACIFIC OCEAN ITS RIVER SYSTEMS Although the area of the Pacific is nearly twice that of the Atlantic, the drainage area of the latter ocean is 2.5 times greater than that of the former, consequently a much smaller number of rivers discharge their waters into the Pacific. This is due to the relief of the continental land masses, which encompass the Pacific almost continuously on three sides, but more especially the American and Australian continents. In South America, the chain of the Andes skirts the coast in unbroken ridges from Patagonia to Panama, at a distance from the coast of from 20 to 80 miles. The steep narrow seaboard of western South America, therefore, admits only of the formation of small rivers—mere mountain-torrents, in fact. The northerly prolongation of the Andes, from Pa nama to the Gulf of California, exhibits the same persistent approximation to the Pacific coast, and consequent absence of any considerable rivers. Further north a minor range still skirts the coast closely, but it is broken in several places to admit of the passage of several streams of considerable size flowing from the more elevated Rocky Mountains—the north ern prolongation of the Andes and Mexican Sierras. In the extreme north the continent juts out in the peninsula of Alaska, while the main mountain range continues its north erly trend unchanged ; and, consequently, here the extended area of development results in the formation of the longest river of Western America, the Yukon, which has a course of 2,000 miles.
In contrast to the mountain-skirted American coast is the eastern, or Pacific, shores of Asia. The sources of the rivers falling into the Pacific are far inland, among the chains that buttress the great central plateau of Asia, so that there is not only a long slope, but also a large and unfailing supply of water. We thus find that the Asiatic section of the Pacific river-system is by far the most important, both in the number and magnitude of its rivers. The Amoor, Hwang-ho, Yang tze-Kiang, Choo-Kiang, and Mekong are, both in volume and length, not inferior to the rivers of Europe or America. But notwithstanding these important accessions, the river-system of the Pacific, as a whole, is inferior to that of the Atlantic. The drainage area of the latter is estimated at 19,050,000 square miles, while that of the Pacific is only 8,460,000 square miles, or about 2i times less.
Our limits do not allow of any extended description of each river, nor does it properly come within the scope of this work to do so ; and we must therefore refer the student to the "Geography of River-Systems," published by Messrs. Philip & Son. The following table shows the locality, length, and area of drainage of the principal rivers flowing into the Pacific