They flow through landscapes of desolate grandeur, vast expanses compassed by endless mountain-ranges that chill the bright skies with never-melting snows. The countless peaks look down on the clouds, while far below the clouds wind valleys that the sunlight never reaches. Twisting in gloomy dusk through these valleys, a gaping canon yawns. Peering fearfully into its black, forbidding depths, an echo reaches the ear. It is the fury of a mighty river, so far below that only a sullen roar rises to the light of day. With frightful velocity it rushes through a channel cut during centuries of patience deep into the stubborn rock. Now mad with whirlpools, now silently awful with stretches of green water, that wait to lure the boatman to death, the mighty river rushes darkly through the Grand Colorado Canon. No sport, no fun, no frolic there. Here are only awe-inspiring gloom and grandeur, and dangers so hideous that only a handful of men have ever braved them--fewer still survived. Grandest of American rivers though it is, you will be glad to get away from it to a noble stream like the Columbia, to a headstrong flood like the Missouri, or an inland sea like the Mississippi; on them at least you can draw a full breath and speak aloud without a feeling that the silent mountains may fall on you or the raging river swallow you up. In the vast territory lying between the Missouri River and the Pacific Ocean the rivers are fast being harnessed for a work that will one day make the most barren spots fertile. Irrigation is claiming every year more of the flow of Western rivers. Even the tricksy old Missouri is contributing somewhat to irrigation, but in the queerest possible way. With all its other eccentricities, the Missouri River leaks badly; for you know there are leaky rivers as well as leaky boats. The government engineers once measured the flow of the Missouri away up in Montana, and again some hundred miles further down stream. To their surprise, they found that the Missouri, instead of growing bigger down stream, as every rational river should, was actually 20,000 second-feet[1] smaller at the lower point. [Footnote 1: The volume of rivers is measured by the number of cubic feet of water flowing past a given point every second. The breadth of the river is multiplied by its average depth, and the ascertained speed of the current gives the number of cubic feet of water flowing by the point of measurement each second. This will explain the term second-feet.]