"About half a mile up this branch," continues Mr Simpson, "in the right-hand escarpment wall, is a hemispherical cave, canopied by some stupendous rocks, a small, cool, acceptable spring being sheltered by it. A few yards further, this branch terminates in an almost vertical wall, affording no pathway for the ascent or descent of troops. At the head of this branch I noticed two or three hackberry trees, and also the _stramonium_, the first plant of the kind we have seen. Retracing our steps to the primary branch we had left, we followed it up to its head, which we found but two or three hundred yards above the fork--the side walls still continuing stupendous, and some fine caves being visible here and there within them. I also noticed here some small habitations, made up of natural overhanging rock, and artificial walls, laid in stone and mortar--the latter forming the front portion of the dwelling." It would be necessary to transcribe the whole of Mr Simpson's minute account of his visit to the cañon and its branches, in order to convey to the reader a just idea of that most extraordinary and gigantic fissure. Even then the idea obtained might be incommensurate with the grandeur of the subject, if the description were unaided by the three plates, dashed off with a bold, rough pencil, in which Simpson's draughtsman has given us a better notion of the grim aspect and huge proportions of the ravine than words could well supply. Having explored the lateral branches, without seeing any sign of the celebrated fort, the party then continued their progress up the main channel, passing some ruined villages, perched on shelves of the rock wall. Near one of these, about five miles from the entrance, they observed, in the bed of the cañon, the ordinary Navajo hut, (a common Indian lodge of conical form, constructed of poles united at the apex, and covered with bark, bushes, and mud,) and, hard by it, a peach orchard. "A mile further, observing several Navajos, high above us, on the verge of the north wall, shouting and gesticulating as if they were very glad to see us, what was our astonishment when they commenced tripping down the almost vertical wall before them as nimbly and dexterously as minuet-dancers! Indeed, the force of gravity, and their descent upon a steep inclined plane, made such a kind of performance absolutely necessary to insure their equilibrium. All seemed to allow that this was one of the most wonderful feats they had ever witnessed."