Atmosphere and the Earth. 245 



Temperature of the Earth in Nishney-tagilsh (Lat. 58°), and 

 Werchoturie (Lat. 59°). 



These two places are situate, as well as Bogoslowsk, on the 

 eastern declivity of the Urals, and are nearly 200 metres above 

 the level of the sea. In Nishney-tagilsk, mine-water, found 

 at a depth of 65 metres, had a temperature of 40°.77. Deduct- 

 ing here, again, 25 metres from the depth, and calculating the 

 number of degrees which the temperature of the earth must de- 

 crease to this depth of 45 metres, we find 37°.l 7 for the tem- 

 perature of the earth in Nishney-tagilsk. A well 5 metres 

 deep indicated 87°.85 : this temperature is somewhat too high 

 (particularly as, from the above quoted observations, wells in a 

 a high latitude ought to shew a lower temperature than 

 springs), which is easily explained, from the observation having 

 been made in autumn, — that is, at the time of the maximum of 

 temperature of deep wells; and the well was not deep enough, 

 to have a constant temperature. 



The Werchoturie, an impetuous spring, had a temperature 

 of 36°.72. Even this temperature is probably a little too high, 

 as the observation was made in autumn. As the springs in 

 Kasan, at that season, have a temperature 0°.45 higher than 

 the mean, we may safely assume that the true mean tempera- 

 ture of the springs in Werchoturie was 36°.27. 



Some experiments are here to be mentioned, which were per- 

 formed in Kuschwa and Bogoslowsk, at the instance of Dr Er- 

 man, and with the assistance of the mining-officer, whose polite- 

 ness was truly exemplary, and which consisted in piercing into 

 the earth with a borer to the depth of 20 feet, and observing 

 the temperature at the deepest point. None of these experi- 

 ments gave a decided result : they always met with water, 

 which, collecting at the bottom of the bore, and coming from 

 the surface, indicated a higher temperature. Perhaps, also, 

 the borings were not deep enough, and the spots not happily se- 

 lected. The temperature of this water was always about 41° 

 and 42°. 12, which was also that of most of the wells near the 

 surface in that quarter. The boring in Kuschwa (Lat. 58°^), 



