its source,--a stream whose cradle is in the same snow-peaks as the Platte,--whose mysterious middle-life, under the new name of the Colorado, flows at the bottom of those tremendous fissures, three thousand feet deep, which have become the wonder of the geologist,--whose grave, when it has dribbled itself away into the dotage of shallows and quicksands, is the desert-margined Gulf of California and the Pacific Sea. Between Green River and the Mormon city no human interest divides your perpetually strained attention with Nature. Fort Bridger, a little over a day's stage-ride east of the city, is a large and quite a populous trading-post and garrison of the United States; but although we found there a number of agreeable officers, whose acquaintance with their wonderful surroundings was thorough and scientific, and though at that period the fort was a rendezvous for our only faithful friend among the Utah Indians, Washki, the Snake chief, and that handful of his tribe who still remained loyal to their really noble leader and our Government, Fort Bridger left the shadowiest of impressions on my mind, compared with the natural glories of the surrounding scenery. Mormondom being my theme, and my space so limited, I must resist the temptation to give detailed accounts of the many marvellous masterpieces of mimetic art into which we find the rocks of this region everywhere carved by the hand of Nature. Before we came to the North Platte, we were astonished by a ship, equalling the Great Eastern in size, even surpassing it in beauty of outline, its masts of columnar sandstone snapped by a storm, its prodigious hulk laboring in a gloomy sea of hornblendic granite, its deck-houses, shapen with perfect accuracy of imitation, still remaining in their place, and a weird-looking demon at the wheel steering it on to some invisible destruction. This naval statue (if its bulk forbid not the name) was carved out of a coarse millstone-grit by the chisel of the wind, with but slight assistance from the infrequent rain-storms of this region. In Colorado I first began to perceive how vast an omission geologists had been guilty of in their failure to give the wind a place in the dynamics of their science. Depending for a year at a time, as that Territory sometimes does, upon dews and meltings from the snow-peaks for its water, it is nevertheless fuller than any other district in the world of marvellous architectural simulations, vast cemeteries crowded with monuments, obelisks, castles, fortresses, and natural colossi from two to five hundred feet high, done in argillaceous sandstone or a singular species of conglomerate, all of which owe their existence almost entirely to the agency of wind. The arid plains from which the conglomerate crops out rarefy the superincumbent air-stratum to such a degree that the intensely chilled layers resting on the closely adjoining snow-peaks pour down to reestablish equilibrium, with the wrathful force of an invisible