82 cosiVK s. 



But the countries bordering on the equator possess anothet 

 advantage, to which sufficient attention has not hitherto been 



veiy desirable that the mean elevation of the Thibetian phiteau, which 

 [ have estiaiated at ouly about 8200 feet between the Himalaya ana 

 tlie Kuen-luu, and the difterence in the height of the line of perpetual 

 snow on the southern and on the northern slopes of the Himalaya, should 

 be again investigated by travelers who are accustomed to judge of the 

 general conformation of the land. Hitherto simple calculations have too 

 often been confounded with actual measurements, and the elevations 

 of isolated summits with that of the surrounding plateau. (Compare 

 Carl Zimmerman's excellent Hypsometrical Remarks in his Geograph- 

 iscken Analyse der Karte von Inner Asien, 1841, s. 98.) Lord draws 

 attention to the difference presented by the two faces of the Himalaya 

 and those of the Alpine chain of Hindoo-Coosh, with respect to the 

 limits of the snow-line. *' The latter chain," he says, "has the table- 

 land to the south, in consequence of which the snow-line is higher on 

 the southern side, contrary to what we find to be the case with respect 

 to the Himalaya, which is bounded on the south by sheltered plains 

 as Hindoo-Coosh is on the north." It must, however, be admitted that 

 the hypsometrical data on which these statements are based require a 

 critical revision with regard to several of their details; but still they 

 suffice to establish the main fact, that the remarkable configuration of 

 the land in Central Asia atfords man all that is essential to the mainte- 

 nance of life, as habitation, food, and fuel, at an elevation above the 

 level of the sea which in almost all other parts of the globe is covered 

 with perpetual ice. We must except the very dry districts of Bolivia, 

 where snow is so rarely met with, and where Pentland (in 1838) fixed 

 the snow-line at 15,6G7 feet, between iG'^ and 17^° south latitude. Tlio 

 opinion that I had advanced regarding the difference in the snow-line 

 on the two faces of the Himalaya has been most fully confirmed by the 

 barometrical observations of Victor Jacquemont, who fell an early sac- 

 rifice to his noble and unwearied ardor. (See his Correspondance 

 pendant son Voyage dans V hide, 1828 a 1832, hv. 23, p. 290, 296,299.) 

 '* Perpetual snow," says Jacquemont, " descends lower on the southern 

 than on the northern slopes of the Himalaya, and the limit constantly 

 rises as we advance to the north of the chain bordering on India. On 

 the Kioubrong, about 18,317 feet in elevation, according to Captain 

 Gerard, I was still considerably below the limit of perpetual snow 

 which I believe to be 19,690 feet in this iraxl of Hindostan." (This 

 estimate I consider much too high.) 



The same traveler says, " To whatever height we rise on the south- 

 ern declivity of the Himalaya, the climate retains the same character, 

 and the same division of the seasons as in the plains of India; the sum- 

 mer solstice being every year marked by the same prevalence of rain, 

 wdiich continues to fall without intermission until the autumnal equi- 

 nox. But a new, a totally different climate begins at Kashmir, whose 

 elevation I estimate to be 5350 feet, nearly equal to that of the cities 

 pf Mexico and Popayan" {Correspond, de Jacquemont, t. ii., p. 58 et 74). 

 The warm and humid air of the sea, as Leopold von Buch well observes, 

 is carried by the monsoons across the plains of India to the skirts of 

 the Himalaya, which arrest its course, and hinder it from diverging to 

 the Thibetian districts of Ladak and Lassa. Carl von HUgel estimates 

 the elevation of the Valley of Kashmir above the level of the sea at 

 5818 feet, and bases his observation on the determination of the lioiliny 



