PLANTH SCHLAGINTWEITIAN E. 119 
sum, in the environs of the lake Mansaraur. Though the valleys are 
high, the relative height up to the chains and summits is still very 
great ; we have but to remember that the passes generally exceed 18,000 
feet, and that of the peaks, the Dapsang Peak, the second in height 
on the globe * as yet known (lat. north, 35° 28’; long. east, Green- 
wich, 77? 10; height, 28,278 feet), is situated in Nubra, in western 
Tibet. A regular plateau we only met with immediately to the 
north of the Karakorum chain, where, over a large extent, the 
country is absolutely uninhabited, and not even visited as pasture- 
ground ; we once travelled twenty-one days without seeing a tent or a 
man," 
“The character of the climate in the different parts of High Asia 
may shortly be defined by the following data :—{ 
“1. For the mean decrease of temperature with height, I obtained, as 
the result of a very great number of observations, 390 English feet for 
1° F. The decrease of temperature with latitude is analogous to that 
in Central Europe, viz. 2° F. for 1° of latitude, but, for general compa- 
rison, it is to be taken into consideration, that the region of High 
Asia, when the isotherma! lines are reduced to the level of the sea, 
decidedly shows a decrease of temperature in the direction from west 
to east. ` 
* 2. The conditions of atmospheric moisture are unusually irregular 
over the different parts of High Asia. In Tibet the annual amount 
of rain varies between two and six inches only, whilst in Sikkim, in 
the eastern Himalaya, it exceeds 120 inches a year. This is of special 
importance with regard to the vegetation; also the difference “ in rela- 
tive humidity of the atmosphere » was also found much greater than 
the few data known till then might have allowed us to expect. In 
Tibet we frequently had a dryness so great that we obtained but 13 per 
cent., even 1 per cent. only of relative humidity,S whilst 16 per cent., 
determined by Humboldt, was the greatest dryness observed till 
is i i than 900 miles distant, I add 
e i As Ne Reig Sets pss us. highest of all; Kanchinjinga, in Sikkim, 
* e - i 
1 ‘Results,’ vol. iv. pp. 3; forthe Alps I had obtained 320 feet for 1° 
F. (Phys. Geog. of the Alps, vol. i. pp. 334-370.) 
§ ‘Results,’ vol. iv. p. 29. 3 
|| ‘Asie Centrale,’ German edition, vol. ii. p. 51. 
