304 M. Humboldt, on hco Attempts to ascend Chimborazo. 



yet of the summit of the mountain 1224 feet, or thrice the 

 height of St Peter's ciuirch at Rome. 



La Condamine and Bouguer say explicitly, that they attained, 

 on Chimborazo, the height of 2400 toiscs only ; but they glory 

 in having seen on the Corazon, — one of the most picturesque 

 snow-mountains (Nevados) in the immediate neighbourhood of 

 Quito, — the barometer at 15 inches 10 lines. They say this is 

 " a lower state than any human being has hitherto ever been 

 in a situation to observe." At the above described point on 

 Chimborazo, the pressure of the air was about two inches less ; 

 less also than at the highest point reached in 1818, sixteen years 

 afterwards, by Captain Gerard, on the Tarhigang, in the Him- 

 malayan Mountains. I have been exposed in a diving-bell in 

 England to an air-pressure of forty-five inches, for almost an 

 hour together. The flexibility of the human organism conse- 

 quently endures changes in the state of the barometer, amount- 

 ing to thirty-one inches. Yet the physical constitution of the 

 human race might be remarkably changed, if great cosmical 

 causes were to make permanent such extremes in atmospheric 

 tenuity and condensation. 



We remained but a short time in this mournful solitude, being 

 soon again entirely veiled in mist. The humid air was not thereby 

 set in motion. No fixed direction was to be observed in single 

 groups of the denser particles of vapour ; I therefore cannot say 

 whether at this elevation the west wind blows, opposing the 

 Tropical monsoon. AVe saw no longer the summit of Chimbo- 

 razo, none of the neighbouring snow-mountains, still less the 

 table-lands of Quito. V\'e were as though isolated in a ball of 

 air. Some stone-lichens only had followed us above the line of 

 perpetual snow. The last cryptogamic plants which I col- 

 lected were Lecidea atrovirens (Lichen geographicus, Web.), 

 and a Gyrophora of Acharius, a new species (Gyrophora ru- 

 gosa), at about the height of 2820 toises. The last moss, Grim- 

 mia longlrostris, grew 400 toises lower down. A butterfly 

 (sphinx) was caught by M. Bonpland at the height of 15,000 

 feet ; we saw a fly 1600 feet higher. The following facts afFcn-d 

 the most striking proof that these animals are involuntarily car- 

 ried up into those upper regions by the current of air which 

 rises from the warmed plains. As Boussingault ascended the 



