filled with ice, especially if near the surface on the north slope of a mountain. Freezing Cave, Fergus County, Montana.--Mr. Robert Butler, of San José, Cal., visited this place, which is about 35 kilometers southeast of Lewistown. It is on the north side of a butte. Masses of ice and great icicles form in some parts of the cave in such quantities during the latter part of winter that the cave furnishes ice for cooling the drinking water for several dozen families. During July and August the people come from some distance around to get the ice. The people in the neighborhood believe that the ice forms in summer and thaws away in winter. They also speak of the ever upward draught of cold air coming possibly from some great hidden cavern in the lower recesses of the mountain. Freezing Well at Horse Plains, Montana. (Levi Allen, _Scientific American_. New Series, 27th October, 1883.)--The well is described as 13.60 meters deep. It is dug through solid gravel, and in sinking it there was encountered, at a depth of 10.60 meters, a current of air strong enough to blow out a candle. It began to freeze in September, 1882, and in November it was frozen solid. Freezing Silver Mine, Bighorn County, Wyoming.--This place is in the Sunlight Basin of the Shoshone Mountains. Mr. William Worrell Wagner, of Philadelphia, informs me that he visited it in August, 1897. It is a silver mine or tunnel, running straight into the mountain for about 60 meters, at an altitude of about 3300 meters. The peaks of the Teton range were in sight from the mouth of the tunnel. For the first half of the way in, a good many icicles were hanging from the rocks. The last half of the tunnel was thickly coated with ice and looked like a cold storage plant. Snow disappears on the rocks outside about June, and begins to fall again in September, so that Mr. Wagner's visit was at about the hottest time of the year. Mr. Wagner presented the meat of a bull wapiti he had shot to the miners, and they stored it in the mine as if it had been an artificial refrigerator. Rifts of Ice, Mount McClellan, Colorado. (Edward L. Berthoud, _American Journal of Science and Arts_. Third Series, 1876, vol. XI., page 108.)--Near the summit of Mount McClellan, is the Centennial Lode, which runs into the mountain, at an altitude of about 3900 meters. Intercalated in the mineral vein are three or four well defined veins of solid ice parallel with the bedding of the rock and filling all its inner side-cracks and fissures. The same frozen substratum is found in two other lodes near by on the same mountain. Nothing of the kind is known on other Colorado mountains. The soil is loose and largely made up of rocky débris, which shows that the ice is probably due to local causes.