The rocks which, where the Columbia breaks through the Chain, form the Cataracts, mark the continuation of the Sierra Nevada de California from the 44th to the 47th degree of latitude. (Frémont, Geographical Memoir upon Upper California, 1848, p. 6.) This northern continuation comprises the three colossal summits of Mount Jefferson, Mount Hood, and Mount St. Helen’s, which rise more than 14540 French or 15500 English feet above the level of the sea. The height of this Coast Chain, or Range, far exceeds, therefore, that of the Rocky Mountains. “During a journey of eight months’ duration which was made along the Maritime Alps,” says Captain Frémont, in his Report, p. 274, “we had snowy peaks always in view; we had surmounted the Rocky Mountains by the South Pass at an elevation of 7027 (7490 E.) feet, but we found the passes of the Maritime Alps, which are divided into several parallel ranges, more than 2000 feet higher;” therefore, only about 1170 feet (1247 E.) below the summit of Etna. It is extremely remarkable, and reminds us of the difference between the eastern and western cordilleras of Chili, that it is only the chain of mountains nearest to the sea (the Californian range), which has still active volcanoes. The conical mountains of Regnier and St. Helen’s are seen to emit smoke almost constantly, and on the 23rd of November 1843, Mount St. Helen’s sent forth a quantity of ashes which covered the banks of the Columbia for forty miles like snow. To the volcanic Coast Range also belong, (in Russian America in the high north), Mount St. Elias, 1980 toises high, according to La Perouse, and 2792 toises, according to Malaspina (12660 and 17850 E. feet), and Mount Fair Weather, (Cerro de Buen Tempo) 2304 toises, or 14732 E. feet high. Both these mountains are supposed to be still active volcanoes. Frémont’s expedition, (which was important alike for its botanical and geological results), collected volcanic products, such as scoriaceous basalt, trachyte, and even obsidian, in the Rocky Mountains, and found an extinct volcanic crater a little to the east of Fort Hall, (lat. 43° 2′, long. 112° 28′ W.); but there are no signs of volcanoes still active, that is to say, emitting at times lava or ashes. We are not to confound with such activity the still imperfectly explained phenomenon of “smoking hills;” “côtes brûlées,” or “terrains ardens,” as they are called by the English settlers, and by natives speaking French. An accurate observer, M. Nicollet, says, “ranges of low conical hills are covered with a thick black smoke almost periodically, and often for two or three years together. No flames are seen.” This phenomenon shews itself principally in the district of the Upper Missouri, and still nearer to the eastern declivity of the Rocky Mountains, where a river bears the native name of Mankizitah-Watpa, or the “river of the smoking earth.” Scoriaceous pseudo-volcanic products, such as a kind of porcelain jasper, are found