192 COSMOS. 



of heat tending towards, but never reaching an equilibrium, 

 sets in from below upwards. The recognition of so many 

 factors acting upon the vertical distribution of heat, leads to 

 well-founded presumptions regarding the connexion of com- 

 plicated local phenomena, but not to direct numerical deter- 

 minations. In the mountain springs (and the higher ones, 

 being important to the chamois-hunter, are carefully sought) 

 there so often remains the doubt that they are mixed with 

 waters, which by sinking down introduce the colder tem- 

 perature of higher strata, or by ascending introduce the 

 warmer temperature of lower strata. From 19 springs, ob- 

 served by Wahlenberg, Kamtz draws the conclusion that in 

 the Alps we must rise from 960 to 1023 feet in order to *ee 

 the temperature of the springs sink 1 C. (1.8 F.). A greater 

 number of observations selected with more care by Hermann 

 and Adolph Schlagintweit in the eastern Carinthian Alps 

 and in the western Swiss Alps on the Monte Rosa, give only 

 767 feet. According to the great work 41 of these excellent 

 observers, " the decrease of the temperature of springs is 

 certainly somewhat more gradual than that of the average 

 annual temperature of the air, which in the Alps amounts 

 to about 320 feet for 1 F. The springs there are in 

 general warmer than the average temperature of the air at 

 the same level ; and the difference between the temperature 

 of the air and springs increases with the elevation. The 

 temperature of the soil is not the same at equal elevations 

 in the entire range of the Alps, as the isothermal surfaces 

 which unite the points of the same average temperature of 

 springs, rise higher above the level of the sea, independently 

 of the influence of latitude, in proportion to the average con- 

 vexity of the surrounding soil ; perfectly in accordance with 

 the laws of the distribution of heat in a solid body of vary- 

 ing thickness, with which the relief (the mass-elevation) of 

 the Alps may be compared." 



In the chain of the Andes, and indeed in those volcanic 

 parts of it which present the greatest elevations, the bury- 

 ing of thermometers may in particular cases lead to decep- 

 tive results by the influence of local circumstances. From 

 the opinion formerly held by me, that black rocky ridges, 

 visible at a great distance, which penetrate the snowy 

 41 Monte Rosa, 1853, chap, vi, s. 212225. 



