Rocky Mountains. 491 



of poets. Thev are called by the Persians sirraub, " water of 

 the desert ;" and in the Sanscrit language Mriga trichna 

 " the desire or thirst of the antelope. 1 ' Elphinstone relates,* 

 that at Moujgur, in the kingdom of Caubul, towards even- 

 ing many persons were astonished at the appearance of along 

 lake enclosing several little islands. Notwithstanding the well 

 known nature of the country, which was a sandy desert, many 

 were positive that it was a lake, and one of the surveyors took 

 the bearings of it. " I had imagined," says he, u this phe- 

 nomenon to be occasioned by a thin vapour which is spread 

 over the ground in hot weather in India, but this appearance 

 was entirely different, and on looking along the ground no 

 vapour whatever could be perceived. The ground was quite 

 level and smooth, and the weather very hot. It is only found 

 in level, smooth, and dry places ; the position of the sun, and 

 the degree of heat, are not material, for it was afterwards 

 seen in Damaun when the weather was not hotter than in 

 England." On the frontier of Caubul Elphinstone saw what 

 he calls a most magnificent mirage, which looked like an ex- 

 tensive lake, or a very wide river. The water seemed clear 

 and beautiful, and the figures of two gentlemen, who rode 

 along it, were reflected as distinctly as in real water. It is 

 common in our own country, says the London Monthly Re- 

 view, for ground- mists to assume the appearance of water, 

 to make a meadow seem inundated, and to change a valley 

 into a lake; but these mists never reflect the surrounding 

 trees and hills. Hence the mirage must consist of a peculiar 

 gas, of which the particles are combined by a stronger attrac- 

 tion of cohesion than the vapours of real water ; the liquor 

 silicum of the alchemists is described as exhibiting, in some 

 circumstances, this glassy surface, yet as being equally 

 evanescent.f It is afterwards suggested, in the same paper, 



* Mission to Caubul, p. 179. 4to. Lond. 

 | See M. Review for May If. 17, p. 3 



