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THE HIMALAYAN MOUNTAINS. 39 
above the camp, and yet there was ‘no snow on its summit. On mountains on the 
N.E. shores of lake Chimororel, which is elevated fifteen thousand feet, the region of 
snow had an uniform margin of nineteen thousand feet. B3 
The above extended notices will serve to give a good idea of the nature of the country 
and climate to be found to the northward of the Indian Himalayas, and enable us to 
appreciate the causes which favour vegetation at such great elevations: the same facts 
have occasionally been repeated, at the danger even of being considered prolix, in 
- consequence of the disposition some time prevalent to doubt the accuracy of observa- 
tions, because they were considered incompatible with theories which were themselves 
deduced from facts, but occurring in regions where all the circumstances are not similar. 
From the details which have been given, it seems abundantly clear that the elevation 
of the Indian snowy range is sufficient to prevent the passage across of the cloudy masses 
which deluge the plains of Northern India with rain, both in the cold and in the warm 
season. The atmosphere, therefore, on the northern face of the Himalayas preserves 
unimpaired the dryness, which is the characteristic of the rarefied air of lofty situations : 
hence the little deposition of snow which takes place in winter in proportion to the 
lowness of the temperature. The returning warmth of spring rapidly dissolves this 
thin layer of snow from level places, in consequence, it appears, of the undiminished 
power of the solar rays in passing through so rare and transparent a medium; a fact 
tending to confirm Mr. Daniels’ views respecting the superior energy of the solar rays 
in the higher regions of the air; and as this seems already to have been done with 
respect to his opinions of their great power in polar regions, the fact is interesting as 
giving an additional cause for the analogy between alpine and polar vegetation. When 
the snow is once melted, these elevated tracts, surrounded and confined by towering 
mountains, absorb heat as readily during the presence of the sun, as they radiate it 
freely while he is absent, and becoming, like the surface of the earth at ordinary 
levels, the source whence the heat received from the sun is diffused to surrounding 
objects, they cause the line of perpetual congelation to recede higher and higher in 
proportion to their own elevation. Peaks and pinnacles, on the contrary, projected into. 
- the air like promontories into the ocean, partake rather of the equability of tempe- 
rature of the media into which they intrude, than impress on them, like plains and 
table-lands, their own extremes of heat and cold, 
“The plants obtained from the most elevated regions of Ludak are few in number, and 
the localities not sufficiently defined to enable us to draw any inferences respecting the 
climate. All were sent by Mr. Mooreroft to Dr. Wallich, and are enumerated in his 
catalogue. The genera are all European, but the species new: the former being 
Gentiana, Aquilegia, Iris, Salsola, Aryris, Potentilla, Campanula, Corydalis, and Salvia. 
- The shrubs are Astragalus, Fraxinus, and Eleagnus, all with the specific name of the 
discoverer. From the fruit of the last, a spirituous liquor is said to be distilled. Some 
of the finest rhubarb that I have ever seen was sent by Mr. Moorcroft from Ludak. In 
the same regions he discovered the celebrated Prangos Hay Plant (Prangos pabularia, 
: : Lindley), 
