AND ITS DISTRIBUTION, 41 



Tt is well deserving of notice that this agreement remained 

 the same whether the " thermometric soundings" of only 

 one foot were made on the hot shores of the Pacific at 

 Guayaquil and Payta, or at an Indian village on the side of 

 the Volcano of Purace, the height of which above the level 

 of the sea I found by barometric measurements to be 1356 

 toises (or 8671 English feet). The mean temperatures 

 differed at these different elevations fully 14 Cent. (25'2 

 Eahr.) ( 41 ) 



Two observations made by myselt in the mountains of 

 Peru and Mexico, are, I think, deserving of particular atten- 

 tion, because made in mines situated at elevations higher 

 than the summit of the Peak of Teneriffe ; and higher, I 

 believe, than any mines into which a thermometer has yet 

 been taken. Thirteen thousand feet above the level of the 

 sea, I found the subterranean air 14 Cent, warmer than 

 the external air. The little town of Micuipampa,( 42 ) in 

 Peru, is situated, according to my determinations of its 

 geographical position and elevation, in 6 43' S. latitude, 

 and at a height of 1857 toises (11875 English feet) above 

 the sea, at the foot of the Cerro de Gualgayoc, celebrated for 

 its mineral (silver) wealth. The summit of this almost iso- 

 lated, castle-like, and picturesque mountain is 240 toises 

 above the pavement of the street of Micuipampa. The 

 temperature of the external air at a proper distance from 

 the entrance of the Mina del Purgatorio was 5'7 Cent. 

 (42*26 Eahr.) ; but everywhere in the interior (at a "height 

 of about 2057 toises, or 15153 English feet above the sea) 1 

 saw the thermometer show 19*8, being a difference of 

 14-1 Cent., or 25 0> 4 Eahr. The limestone rock was 

 perfectly dry, and there were very few miners at work. In 



