in Colombia between the Years 1820 a7id 1830. 17 



the earthquake of 1812„ It would be difficult to explain how 

 the temporary evolution of volcanic gases, supposing such to 

 have taken place, could operate any permanent change on the 

 surrounding atmosphere ; yet other causes may have produced 

 an effect falsely ascribed to the phaenomenon most impressed 

 on the imagination of the inhabitants. On looking over Hum- 

 boldt's collection of observations for December and January, 

 1799, we find the thermometer seldom rise to 75°, and often 

 sink to 59°; so that the mean of these months is about 68°. 

 During the same months in 182], the dail}' range was from 

 65° to 76°. I never observed it lower than 61°*5, and on one 

 occasion, at 5 a.m., it stood at 6P*0. The mean of these two 

 months is 70°"21, or 2°'21 higher than the estimate of Hum- 

 boldt. The clearness and beauty of the sky, during almost 

 the whole period of my residence, is also a circumstance op- 

 posed to Humboldt's ^'caelum scepe nubibus grave quce jJost solis 

 occasum terra; approplnqiiant" — De Di&tributione Geog. Plant. 

 p. 98. I remember but once to have seen a fog in the streets 

 of the city. Future observations will show whether any change 

 of climate has really taken place, or whether the differences 

 observed be only such variations as may be fi'equently re- 

 marked in the same place betwixt one year and another. The 

 mean of the whole temperate mountain region may be reckoned 

 at 67°'80 ; that is, if we limit ourselves to the districts partially 

 cultivated and inhabited. The declivities of the Andes, still 

 covered with vast and humid forests, have probably their tem- 

 perature proportionably lowered. Thus the village of Mindo, 

 on the western declivity of Pichincha, embosomed in humid 

 forests, at 3932 feet of elevation, has a medium temperature 

 of 65"'5, the same with that of Popayan. 



4. The elevated plains of the Andes, betwixt 8000 and 

 ] 1,000 feet, on which were anciently united the most power- 

 ful and civilized indigenous nations beneath the dominion of 

 the Zipas of Tunja and Bogota and the Incas of Quito, and 

 where the great mass of Indian population is still to be found, 

 have a general medium temperature of 59°'37, modified how- 

 ever by local circumstances, and particularly by the proximity 

 of the Nevados. Thus the village of Guaranda, placed at the 

 base of Chimborazo, though nearly 500 feet less elevated, is 

 at least one degree colder than the city of Quito, sheltered 

 on all sides by the ramifications of Pichincha. The city 

 again is above one degree warmer than its suburbs on the 

 plains of Anaguito and Turupamba to the north and south, 

 lliobamba is about 200 feet below Quito ; yet its situation on 

 an open plain, bordered by the snowy mountains of Chim- 

 borazo, Tunguragua, and La Candelaria, renders the climate 



P/til. Mag. 8. 3. Vol. M'. No. 85. Juji. 1839. C 



