126 Notes on Central Asia. [No. 3, 



might be used for such au amplification are as yet but little digested. 

 The travels of Fedorof, Karelin, Schrenk, my own, the observations 

 of G-olubef, the data collected and elaborated by Fakharof, have not 

 yet appeared in print, and only short notices of them have been 

 presented. I am consequently necessarily obliged to withhold the 

 supplementary matter to the 2nd volume, at all events until the 

 publication of my travels which is now delayed by all my time and 

 attention being engaged on questions of pressing and vital importance 

 to Russia. 



With regard to the 3rd volume of the Russian edition of Ritter's 

 Asia, containing a description of the Russian Altai, the not unim- 

 portant materials relating to these mountains, which were collected 

 by me on my journey, have been partly digested since my return, and 

 I am therefoi - e in a position to proceed at once with the publication 

 of this volume with its supplementary portion. I think it necessary 

 to allude briefly in this place to some of the general results of my 

 visits to the Celestial mountains. They embrace three questions of 

 the utmost importance to the geography of Asia, namely the height 

 of the snow-line in the Celestial range, the existence of alpine glaciers, 

 and the existence of volcanic phenomena in this region. 



On the first of these points I consider it incumbent on myself to 

 dwell at length in reply to the doubts expressed by Humboldt as to 

 the correctness of the elevation of the snow-line in the Celestial range, 

 as determined by me. The height I fixed it at, namely 11,000 to 

 11,500 feet, was ascertained by Humboldt from a letter I wrote to 

 Ritter, which attracted his particular notice. This letter was pub- 

 lished in the " Zeitschrift fur Erdkunde" with some explanatory 

 remarks hy Humboldt. The method I adopted for ascertaining the 

 height of the snow-line was not known to Humboldt, who grounded 

 his supposition of an over-estimation of the elevation of the snow-line 

 on certain theoretical and analogical considerations. 



Inaccuracies in the determination of the height of the snow- 

 line may arise from two sources first from what is taken to be the 

 snow-line, and secondly from an imperfect method of measuring 

 heights. 



In the first instance the observer may be deceived either by taking 

 dissolvable for eternal snows, or by fixing their limit of height in 



