XV111 SUMMABY. STEPPES AND DESERTS. 



Modern views on the mountain systems of the two American 

 peninsulas. Chains, which have a direction from S.W. to N.E., in 

 Brazil and in the Atlantic portion of the United States of North 

 America. Depression of the Province of Chiquitos; ridges as water- 

 marks between the Guapore and Aguapehi in 15 and 17 south lat., 

 and between the fluvial districts of the Orinoco and Rio Negro in 2 

 and 3 north lat. pp. 29-31. 



Continuation of the Andes-chain north of the isthmus of Panama^ 

 through the territory of the Aztecs, (where the Popocatepetl, recently 

 ascended by Capt. Stone, rises to an altitude of 17,720 feet,) and through 

 the Crane and Rocky Mountains. Valuable scientific investigations of 

 Capt. Fremont. The greatest barometric levelling ever accomplished, 

 representing a profile of the ground over 28 of longitude. Culminating 

 point of the route from the coast of the Atlantic to the South 

 Sea. The South Pass south ward of the Wind-River Mountains. Swell- 

 ing of the ground in the Great Basin. Long disputed existence of 

 Lake Timpanogos. Coast-chain, Maritime Alps, Sierra Nevada of Cali- 

 fornia. Volcanic eruptions. Cataracts of the Columbia River pp. 

 31-38. 



General considerations on the contrast between the configuration of 

 the territorial spaces, presented by the two diverging coast-chains, east 

 and west of the central chain, called the Rocky Mountains. Hypsometric 

 constitution of the Eastern Lowland, which is only from 400 to some- 

 what more than 600 feet above the level of the sea, and of the arid 

 uninhabited plateau of the Great Basin, from 5000 to more than 6000 

 feet high. Sources of the Mississippi in Lake Istaca according to 

 Nicollet, whose labours are most meritorious. Native land of the 

 Bisons; their ancient domestication in Northern Mexico asserted by 

 Gomara pp. 38-42. 



Retrospective view of the entire Andes-chain from the cliff of Diego 

 Ramirez to Behring's Straits. Long prevalent errors concerning the 

 height of the eastern Andes-chain of Bolivia, especially of the Sorata 

 and Illimani. Four summits of the western chain, which, according 

 to Pentland's latest determinations, surpass the Chimborazo in height, 

 but not the still-active volcano, Aconcagua, measured by Fitz-Roy 

 pp. 42-44. 



The African mountain range of Harudje-el-Abiad. Oases of vegeta- 

 tion, abounding in springs pp. 44-46. 



Westerly winds on the borders of the desert Sahara. Accumulation 

 of sea-weed ; present and former position of the great fucus-bank, from 

 the time of Scylax of Caryanda to that of Columbus and to the present 

 period pp. 46-50. 



Tibbos and Tuaryks. The camel and its distribution pp. 50-53. 



Mountain-systems of Central Asia between Northern Siberia and 

 India, between the Altai and the Himalaya, which latter range is aggre- 

 gated with the Kuen-liin. Erroneous opinion as to the existence of 

 one immense plateau, the so-called "Plateau de la Tartarie" pp. 53-56. 



