National Geographic : 1897 Feb
48 CRATER LAKE, OREGON sible that other small volcanic cones might be found. This sug gestion is borne out by the soundings of the lake, which appear to reveal two other cases, but they do not rise to within 400 feet of the surface of the water. It is evident that the volcanic eruptions upon the bottom of the pit have partially filled it up. Originally it may have been much more than 4,000 feet deep. Given the pit with water-tight walls, there is no difficulty in forming Crater lake, for in that region precipitation is greater than evaporation. The lake does not fill up and overflow. The surplus water must have a subterranean outlet, probably toward the southeast, where the region is traversed by extensive breaks in the rocks, and abounds in excellent springs. The color of the lake is deep blue excepting along the borders, where, it merges into various shades and tints of green. It is so transparent that even on a hazy day a white dinner plate 10 inches in diameter may be seen at a depth of nearly 100 feet. It contains no fish, but a small crustacean flourishes in its waters, and salamanders occur in abundance locally along the shore. The level of the lake oscillates with the seasons. During the rainy winter it rises, and in the summer it falls. In August last observations were made for twenty-two days, and the lake sank at the rate of one inch for every five or six days, depending somewhat on the conditions of the weather. The Mazamas have established a water gauge, and it is hoped that an extended series of observations may be obtained in the future. Mr B. W. Evermann, of the U. S. Fish Commission, who vis ited the lake last summer, made some interesting observations of its temperature. At 1 p. m., August 22 The temperature of the surface water was. ...................... 600 At a depth of 555 feet the temperature was..................... 390 At a depth of 1,043 feet the temperature was ..................... 410 At a depth of 1,623 feet (on the bottom) the temperature was. ..... 460 The increase of temperature with the depth suggests that the bottom may yet be warm from volcanic heat, but more observa tions are needed to fully establish such an abnormal relation of temperatures in a body of water. Aside from its attractive scenic features, Crater lake affords one of the most interesting and instructive fields for the study of volcanic geology to be found anywhere in the world. Consid ered in all its aspects, it ranks with the Grand Canyon of the Colorado, the Yosemite valley, and the Falls of Niagara, and should be set aside as a National Park for the pleasure and in struction of the people.