PREFACE. X1U 



and the shores of the Caspian Sea) in the year 1829, with 

 Ehrenberg and Gustavus Rose, at the command of the Em- 

 peror of Russia, took place between the second and third 

 editions of my work. This expedition has essentially con- 

 tributed to the enlargement of my views in all that con- 

 cerns the formation of the earth's surface, the direction of 

 mountain-chains, the connexion of the Steppes and Deserts, 

 and the geographical distribution of plants according to ascer- 

 tained influences of temperature. The ignorance which has 

 so long existed respecting the two great snow-covered moun- 

 tain-chains, the Thian-schan and the Kuen-liin, situated 

 between the Altai and Himalaya, has (owing to the inju- 

 dicious neglect of Chinese sources of information) obscured 

 the geography of Central Asia, and propagated fancies in- 

 stead of facts, in works of extensive circulation. Within 

 the last few months the hypsometric comparisons of the 

 culminating points of both continents have unexpectedly 

 received important and corrective illustration, of which I am 

 the first to avail myself in the following pages. The measure- 

 ment (now divested of former errors) of the altitude of the 

 two mountains, Sorata and Illimani, in the eastern chain of 

 the Andes of Bolivia, has not yet, with certainty, restored the 

 Chimborazo to its ancient pre-eminence among the snowy 

 mountains of the new world. In the Himalaya the recent 

 barometric measurement of the Kinchin-jinga (26,438 

 Parisian, or 28,178 English feet) places it next in height 

 to the Dhawalagiri, which has also been trigonometrically 

 measured with greater accuracy. 



To preserve uniformity with the two former editions of the 

 Views of Nature, the calculations of temperature, unless 

 where the contrary is stated, are given according to thp 



