“I am surprised to find that water has had so little to do with the mountain structure of this region. None of the upper Merced streams give record of floods greater than those of to-day. The small water channel, with perpendicular walls, is about two feet in depth a few miles above the Little Yosemite. The Nevada here, even in flood, never was more than four or five feet in depth. Glacial striæ and glacial drift, undisturbed on banks of streams but little above the present line of high water mark, is sufficient proof.” The views entertained by Mr. Muir are, for the most part, in consonance with my own. That the valley was originally formed as supposed by Prof. Whitney I do not doubt, but to suppose that the vast bodies of ice, stated by Mr. Whitney to have existed at the sources of the Merced river, could have halted in their glacial flow down the steep declivities of its canyons, seems as absurd as to suppose one entertaining opposite views “ignorant of the whole subject.” As a matter susceptible of eternal proof, I will state that in the canyon below the Yosemite there are existing to-day, large, well rounded bowlders that I think a geologist would say had been brought from above the valley; and if so, water alone could scarcely have brought them over the sunken bed of the valley, or if filled to its present level of about thirty-five feet descent to the mile, the laws that govern aqueous deposits would have left those huge masses of rock far above their present location in the canyon. Some of the bowlders referred to will weigh twenty tons or more, and, in connection with flat or partially rounded rocks fallen, probably, from the adjacent cliff, form waterfalls in the middle of the canyon, of from fifty to one hundred feet of perpendicular height. The fall through the canyon averages over two hundred feet to the mile. Well rounded bowlders of granite and other hard stones may be seen for long distances below the Yosemite, on hillsides and flats far above the present bed of the river, and, in some instances, deposited with those bowlders, have been found well rounded and swedged masses of gold. The experiments and observations of Agassiz, Forbes and others, render it probable that the valley of the Yosemite was filled with ice, but that the upper surface moved more rapidly, carrying down most of the material brought from mountains above the valley. The observations of Prof. Tyndall render it almost certain that a glacier does not move as a rigid mass or on its bed, but as a plastic substance, as asphalt for instance.