298 M. Humboldt on two Attempts to ascend Chimhoraza. 



for example, of Luneburg (Lat, 53°16') ; but here the distri- 

 bution of heat among the different months (the most important 

 element in determining the character of the vegetation of a 

 country) is so unequal, that in February, the mean heat is 

 — 1°.8 (+28°. 76 F.), in July + 18° (+ 64°.4 F.) 



My plan was to perform a trigonometrical operation in the 

 beautiful perfectly level grass land of Slsgun. I had made arrange- 

 ments for measuring a base line here. The anoles of altitude 

 would have proved very considerable in such proximity to the 

 summit of Chimborazo. There remained yet a perpendicular 

 height of less than 8400 feet (the height of the Canigou in the 

 Pyrenees) to determine. Yet with the enormous masses of single 

 mountains in the chain of the Andes, every determination of the 

 height above the sea is compounded of a barometrical and trigo- 

 nometrical observation. I had taken with me the sextant and 

 other instruments of measurement in vain. The summit of 

 Chimborazo remained densely veiled in mist. From the high 

 plain of Sisgun the ascent is tolerably steep as far as the little 

 alpine lake of Yana-Coche. Thus far I had remained on the 

 mule, having from time to time alighted with my travelling com- 

 panion M. Bonpland merely to collect plants. Yana-Coche 

 does not deserve the name of a lake. It is a circular basin of 

 scarcely 130 feet in diameter. The sky became moi-e and more 

 obscured ; but between and over the mist-strata there still lay 

 scattered single groups of clouds. The summit of Ciiimborazo 

 was visible for a few moments only at a time. Much snow 

 having fallen during the preceding night, I left the mule where 

 we found the lower border of this newly-fallen snow, a border 

 which must not be confounded with the limit of perpetual snow. 

 The barometer shewed that we had only now attained the height 

 of 13,500 feet. On other mountains, likewise near to the equa- 

 tor, I have seen snow fall at the height of 11,200 feet, but not 

 lower. My companion rode as far as the line of perpetual snow, 

 i. e. to the height of Mont Blanc ; which mountain, as is known, 

 would not in this latitude (1° 27' south) always be covered with . 

 snow. The horses and mules remained there to await our re- 

 turn. 



A hundred and fifty toises above the little basin of Yana- 

 Coche, we saw at length naked rock. Hitherto the grass-land 



