102 Captain Thomas Hutton's Remarks on the 



more powerfully than from the southern plains, and will drive the 

 snow-line to a greater elevation above the sea on the northern than 

 on the southern aspect. Thus Humboldt's theory, when applied to 

 the Kumaon and other similar districts, appears to be perfectly 

 correct. But that the physical features of the Kumaon and western 

 tracts are at the antipodes of each other, has been plainly stated by 

 Mr Batten, who says — " Our passes at once take us into Tibet, 

 and do not conduct us, like those beyond Simlah, into an interme- 

 diate and peculiar tract, like Kunawur." * Now it seems to me by 

 no means improbable that this very difference in the features of the 

 two tracts may be sufficient to account for the difference in the phe- 

 nomena observable in each, and that if Humboldt's theory of radia- 

 tion from the plains of Tibet is sufficient to account for the retreat 

 of the snow to the heights of the northern face, the want of similar 

 plains f in the western tracts will of course preclude such radiation 

 from acting on the northern face of the western mountains, and thus 

 the greater heat of the southern side, added to the periodical rains 

 and to the violence of the winds in winter, will leave snow on the 

 northern long after it has disappeared from the southern aspect. 



Lieut. Strachey admits that the rains have a powerful effect 

 in melting the snows ; but his want of knowledge of the localities to 

 the westward has led him into an error, when he supposes that the 

 monsoon does " not extend up the Sutlej beyond the point where 

 the Burpa falls into it ;" the truth being that Chini, which is itself 

 farther up, and situated in the gorge where the Sutlej breaks 

 through the outer snowy range, is full within the monsoon, as both 

 Captain Jack and I experienced ; beyond this point the rains are 

 light and uncertain, but they nevertheless extend to the head of the 

 district, for clouds and vapours pass onwards through the valley of 

 the Sutlej, even to the upper parts of Kunawur, and exercise great 

 influence on clearing the southern slopes of their snow ; and although 

 Lieut. Strachey has assumed that clouds protect the snow, by 

 warding off the direct rays of the sun, he overlooks the fact that 

 such clouds betoken a humid atmosphere, which is quite as inimical 

 to the duration of the snow as the sun's rays, and he might, at least 

 during his scientific researches in Kumaon, have learnt the fact that 

 thaws are more rapid in cloudy weather than in a dry and unclouded 

 atmosphere, such as that which he acknowledges to be the general 

 characteristic of the northern aspect. 



Dr Lord's remarks on the Hindu Cush coincide apparently with 

 mine to the north of the Bissehir range ; and since Webb's obser- 

 vations in Kumaon are found to be only locally true, there can be 

 little doubt that Dr Lord"'s surmise relative to the effect of heat 



* Cal. Jour. Nat. Hist., No. 19. 



t Captain Cunningham seems to doubt the existence of any plains at alL- 

 Vide J. A. S., No. 206, for 1849. 



