290 On the Snow-line in the Himalaya. [April» 



without meeting any further obstacle on his road at all comparable to 

 that he has passed, or perhaps even without again crossing snow.* 



Without waiting to enquire whether either of our travellers has in 

 fact come to a just conclusion, it will be sufficient for my purpose to 

 point out that they mean totally different things by their north and 

 south declivities ; and it will be indeed surprising if they agree as to the 

 position of the snow line. It is manifest therefore that before we can 

 expect to arrive at any correct results, we must get rid of the confusion 

 caused by the ambiguity of the terms north and south declivity ; terms 

 which at the best are very ill adapted to convey definite ideas of posi- 

 tion in so vast and complicated a mass of mountains. In spite of every 

 care, they will constantly be liable to misconception, as must always be 

 the case where a restricted signification is arbitrarily applied, in a dis- 

 cussion of this sort, to expressions which of themselves have an extend- 

 ed general meaning.f 



As a substitute for the declivities then, the best standard that occurs 

 to me, to which to refer when alluding to the elevation of the snow- 

 line at any place, is the general mass of perpetual snow found on the 

 more elevated parts of the Himalaya, the belt of perpetual snow, which 

 as I before stated, is about 35 miles in breadth, and runs along the 

 northern boundary of the chain. Instead of the height of the snow-line 

 on the northern or southern declivity, I shall therefore say, the height 

 at the northern or southern limit of the belt of perpetual snow, where 

 the limits of the belt of perpetual snow, are to be understood as having 

 exactly the same relation to the snowy surface in a horizontal plane, 

 that the snow-line has in a vertical. 



It remains for me to define clearly what is meant by the snow-line, 

 and I cannot do better than adopt the words of M. Humboldt, who 

 says, " the lower limit of perpetual snow in a given latitude is the 

 boundary line of the snow which resists the effect of summer ; it is the 

 highest elevation to which the snow-line recedes in the course of the 

 whole year. We must distinguish between the limit thus defined, and 

 three other phenomena ; viz. the annual fluctuation of the snow-line ; 

 the phenomenon of sporadic falls of snow, and the existence of 

 glaciers" (Cosmos. Trans. T. 1. p. 327). 



* The ordinary route lies up the bank of the Sutlej. 



f As a specimen, vide Capt. Hutton's papers noticed hereafter. 



