The main stream is two thousand five hundred and three miles in length, or more truly four thousand one hundred and ninety miles, if the Mississippi and Missouri be taken; that is, many times the length of the Seine. As Mark Twain, who is to be forever associated with its history, has said, it is "the crookedest river" in the world, travelling "one thousand three hundred miles to cover the same ground that a crow would fly over in six hundred and seventy-five." For a distance of several hundred miles the Upper Mississippi is a mile in width. Back in 1882 it was seventy miles or more [Footnote: Mark Twain, "Life on the Mississippi," p. 456.] wide when the flood was highest, and in 1912 sixty miles wide. The volume of water discharged by it into the sea is second only to the Amazon, and is greater than that of all European rivers combined--Seine, Rhine, Rhone, Po, Danube, and all the rest, omitting the Volga. The amount is estimated at one hundred and fifty-nine cubic miles annually--that is, it would fill annually a tank one hundred and fifty-nine miles long, a mile wide, and a mile high. With its tributaries it provides somewhat more than sixteen thousand miles of navigable water, more than any other system on the globe except the Amazon, and more than enough to reach from Paris to Lake Superior by way of Kamchatka and Alaska--about three-fourths of the way around the globe. The sediment carried to the sea is estimated at four hundred million tons [Footnote: Humphrey's and Abbot's estimate.] annually. As one has put it, it would require daily for its removal five hundred trains of fifty cars, each carrying fifty tons, and would make two square miles each year over a hundred and thirty feet deep. Mark Twain in "Life on the Mississippi" is authority for the statement that the muddy water of the Missouri is more wholesome than other waters, until it has settled, when it is no better than that of the Ohio, for example. If you let a pint of it settle you will have three-fourths of an inch of mud in the bottom. His advice is to keep it stirred up. [Footnote: "Life on the Mississippi," p. 182.] The area which it drains is roughly a million and a quarter square miles, or two-fifths of the United States. That is, as one graphic historian has visualized it in European terms, Germany, Austria-Hungary, France, and Italy could be set down within its limits and there would still be some room to spare. The river has the strength (for the most part put to no use) of sixty million horses. The difference between high water and low water in flood conditions is in some places fifty feet, which shows that it has a wider range of moodiness than even the Seine.