M. Huluboldt on two Attempts to ascend Chimborazo. 307 



shewn, in another place (in a treatise on the causes which con- 

 ditionate the curvature of isothermal lines incorporated into one 

 oi iheji-agmens Asiatique), that in the province of Quito, the 

 differences in height of the snow-line on the different Nevados, 

 according to the sura-total of my measurements, varies only 

 about 38 toises, — that the mean height itself is to be reckoned 

 14,760 feet, or 2460 toises, — and that this limit in Bolivia, W 

 to 18° south of the equator, on account of the relation of the 

 mean annual temperature to the mean temperature of the hot- 

 test months, on account of the mass, extent, and greater height 

 of the surrounding heat-radiating joZa^m?^.?, on account of the 

 dryness of the atmosphere, and the complete absence of any fall- 

 ing snow between March and November, Ues at a height of full 

 26,780 toises. The lower limit of perpetual snow, which by no 

 means coincides with the isothermal curve of 0°, rises consequent- 

 ly higher, as an exception, instead of falling, as one recedes from 

 the equator. From quite analogous causes of the radiation of heat 

 in neighbouring table-lands, the snow-line lies between 30^° and 

 31° of northern latitude, on the northern Thibet side of the 

 Himmalayan range, at the height of 2600 toises ; while on the 

 southern Indian side, it reaches the height of only 1950 toises. 

 Through this remarkable influence of the shape of the earth's 

 surface, a considerable part of inner Asia, beyond the Tropics, 

 is inhabited by an agricultural population, who, though monk- 

 governed, are advanced in civilization ; where in South Ame- 

 rica, under the equator, the ground is covered with eternal ice. 

 We took a somewhat more northern way back to the village 

 of Caipi than the Lianas de Sisgum, through the Paramo de 

 Pungupala, a district rich in plants. By five o'clock in the 

 evening we were again with the friendly clergyman of Calpi. 

 As usual, the misty day of the expedition was succeeded by the 

 clearest weather. On the 25th of June, at Riobamba Nuevo, 

 Chimborazo presented itself in all its splendour, — I may say, in 

 the calm greatness and supremacy which is the natural charac- 

 ter of the tropical landscape. A second attempt upon a ridge 

 interrupted by a chasm, would certainly have turned out as 

 fruitless as the first, and I was already engaged with the trigo- 

 nometrical measurement of the volcano of Tungurahua. 



VOL. XXIII. XO. XLVI. OCTOBER 1837. X 



