128 Notes on Central Asia. [No. 3, 
But Humboldt could not have taken exception to the method used 
in measuring the height of the snow-line, in the Tian-Shan, because 
he at that time did not know what means were used for this purpose, 
and also because he himself adopted the same method on his journey 
in the New World, which was so prolific of scientific results. Hum- 
boldt’s doubts respecting the probability of the height of the Tian- 
Shan snow-line (as fixed by me), being considerable, were based on 
considerations of comparative geography, and their soundness or other- 
wise may be easily tested, for they were founded on a comparison 
of their height of snow-line, 11,000 to 11,500 feet, with its well 
ascertained limits in nearly the same meridian (in the Altai, 6,600 
feet) or in the same parallel, (the Pyrennees, 8,400 feet and the 
Caucasus, 10,170 feet). 
In examining the observations made by any traveller respecting 
the elevations of the snow-line, the most accurate scientific criticism 
must test their correctness, by the following theoretical investiga- 
tions. 
The height of the snow-line in a given range, must be calculated 
theoretically on the basis of a comparison with other ranges, on the 
same meridian, and the same parallel; the obtained results should 
then be compared with the figures arrived at by actual observation, 
and it must then be carefully considered whether the discrepancy that 
may occur can be at all attributed to considerations of climate, and 
local peculiarities. 
Humboldt, in his classical work “ Asie Centrale,” supplies us with 
the requisite figures for arriving at a definite conclusion. 
In the same meridian with the Celestial mountains we find that the 
height of the snow-line is as follows, 
In the Altai (Tigerski Belki) 
Tigitin Sl IN ORB oer en i dee rce aes 6,600 feet. 
On the Northern slope of the Himalayan range, 
Daa, So. INO TEE so cn etnn «canis ik aan ... 15,600 feet. 
The Celestial mountains extend at the part visited by me, between 
Lat. 41° and 42° North which is consequently mid-way between the 
Altai and Himalayas. Taking the mean of the figures given above 
we shall get 11,100 feet for the height of the snow-line of the Celestial 

