Continuation of the chain of the Andes north of the isthmus of Panama (through the Aztec country, where Popocatepetl, 16626 French, or 17720 English feet high, has very recently been again ascended by Captain Stone) in the Sierra de las Grullas and the Rocky Mountains. Excellent scientific investigations of Captain Frémont. The longest barometric levelling ever made, showing a profile or vertical section of the earth’s surface through a space of 28° of longitude. Culminating point of the route from the coast of the Atlantic to the Pacific. “South Pass,” south of the Wind River Mountains. Swelling of the ground in the Great Basin. Long contested existence of the Timpanogos Lake. Coast Chain, Maritime Alps, or Sierra Nevada of California. Volcanic eruptions. Falls of the Columbia 39-50 General considerations on the contrasts shown by the spaces included between the central chain (the Rocky Mountains) and the diverging chains on the east and west (the Alleghanies and the Sierra Nevada of California); hypsometric characters of the low eastern space, which is only from 400 to 600 French, or 426 to 639 English feet above the level of the sea, and of the arid uninhabited plain 5000 or 6000 (5330 to 6400 English) feet above the same level, called the Great Basin. Sources of the Mississipi in the Lake of Istaca according to Nicollet’s highly meritorious researches. Buffalo country; Gomara’s assertion of buffaloes having been formerly tamed in the northern part of Mexico 50-55 Retrospective view of the chain of the Andes from the Rocks of Diego Ramirez to Behring’s Strait. Long circulated errors respecting the heights of mountains in the eastern chain of the Andes of Bolivia, especially the Sorata and the Illimani. Four summits of the western chain of Bolivia, which, according to Pentland’s latest determinations, are higher than the Chimborazo, but are not equal in height to the still active volcano of Acongagua measured by Fitz-Roy 55-58 The African mountains of Harudsch-el-Abiad. Oases 58-60 West winds on the coast of the Sahara. Accumulation of sea-weed; position of the great bank of Fucus from the time of Scylax of Caryanda to that of Columbus, and to the present day 60-67 Tibbos and Tuaricks. The camel and its distribution 67-71 Mountain systems of the interior of Asia between Northern Siberia and India. Erroneous belief in the existence of a single great elevated plain called “Plateau de la Tartarie” 71-75 Chinese literature a rich source of orographic knowledge. Series of elevations of different highlands. Desert of Gobi. Probable mean height of Thibet 75-85