962 Remarks on the Snow line in the Himalaya. [Sept. 



effects of the above agents we add the fact that the violent southerly 

 winds of winter have a tendency to keep the southern slopes free from 

 snow and to accumulate it in drift on the north, we appear to have 

 every fact leading to the conclusion that the snow will, as a general 

 rule, be found longer and deeper on the north than on the south ; and 

 Captain Cunningham has stated that when (even in winter) there was 

 little or no snow on southern aspects, it was sometimes "four feet 

 thick" on the north ! 



The very admission therefore that the northern destructive agents 

 exert little influence on the snow, would of itself be sufficient to over- 

 throw thus much of Lieut. Strachey's theory ; for if those agents which 

 drive the snow to a certain elevation are removed, it is evident that 

 the snow, whether much or little, must remain nearly or altogether 

 intact. 



We are further told that, " the air that comes up from the south, 

 no sooner reaches the southern boundary of the left of perpetual snow, 

 where the mountains suddenly rise from an average of perhaps 8,000 

 or 10,000 feet, to nearly, 19,000 or 20,000, than it is deprived of a 

 very large proportion of its moisture, which is converted into cloud, 

 rains or snow, according to circumstances. — And the current in its pro- 

 gress to the north, will be incapable of carrying with it more moisture 

 than is allowed by the very low temperature to which the air is of 

 necessity reduced in surmounting the snowy barrier, 19,000 or 20,000 

 feet in altitude, that it has to pass. Nor can any further condensation 

 be expected at all comparable in amount to what has already taken 

 place, as it would manifestly demand a much more than corresponding 

 depression of temperature ; and this is not at all likely to occur, for 

 the most elevated peaks being situated near the southern limit of per- 

 petual snow, the current on passing them will more probably meet 

 with hotter than with colder air." 



I must confess that this theory does not appear to me to be either 

 conclusive or even probable ; for in the first place, we are neither fur- 

 nished with any proof that the air will be hotter to the north of the 

 high peaks, nor with any approach to data for determining the ques- 

 tion ; the whole resting upon the unauthorised assumption of a de- 

 sired fact, the existence of which is absolutely necessary to give any- 

 thing like validity to the theory. 



