And now we are going down into the vastest canyon in the world, a canyon so vast that it has already swallowed practically all the words in the dictionary suitable to such scenery and still remains undescribed--so all the skilled writers say who have tried their hands at it. This is the Grand Canyon of the Colorado. Do you remember how in "Alice in Wonderland" the cat disappeared and left nothing but its smile? Well, the first time you see the Grand Canyon you feel as if it had swallowed you and left nothing but your eyes! And when they tell you that it was all done by that little river that you can just make out threading its way along the bottom, you can't believe it! The total length of the river's gorge--a canyon is just a long gorge--is some 400 miles. The part of it known as the Grand Canyon is a yawning abyss of stone into which the river walls widen for a distance of 42 miles. The Lower Colorado River, that dug this chasm in the rock, flows through a vast table-land where rain seldom falls. But the river, which rises in the Rocky Mountains, has a constant supply of water from the mountain rains and the melting snow. The canyons you see branching from the main gorge in our picture were cut by the Colorado's tributaries. Working together on different sides, they carved out those rock masses that look like oriental temples and have been named accordingly--the temples of Brahma, Osiris, Zoroaster, and so on. And here in this canyon is a splendid example of how the rivers, in addition to all their other labors, write history. They helped to lay down on the borders of the ancient sea the material out of which the rocks were made. It is in the leaves in such books of stone that the geologist reads the great events of world-making history. Moreover, the rivers may be said to cut the leaves of the book when they dig down through them, as in this immense library of the Grand Canyon. [Illustration: _From a photograph copyrighted by Fred Harvey_ AND WE PEBBLES HELPED DIG THE GRAND CANYON, TOO! River water alone couldn't cut those canyons--the Grand Canyon and the rest. The Colorado and its tributaries had to have grinding tools and the tools were the pebbles they dragged over their rock-beds; and thus, in the course of ages, wore them down and down and down. ] Busy, busy all the time--these rivers. But although they are always at work they not only never forget to look beautiful but they beautify everything they touch. At the outset the lines of a river valley are rather straight and angular, as if the scenery were just being blocked out by an artist, but as the valley grows older its slopes become more gentle, the angles disappear into rounded forms, and the river itself winds along in graceful lines, exactly reproducing what the great English artist Hogarth called "the line of beauty." [Illustration: THAT MIGHTY RIVER IN THE MEADOWS