Hot and Thermal Springs, S67 



coutit for this great difference by supposing the temperature of 

 the air at Konigsbcrg to have been probably determined much 

 too low ; for at Mitau, which hes J^° farther to the north, and 

 rather to the east, it has been found l°.t35 higher.* 



The temperature of the springs near Berlin and Potsdam 

 strengthened Erman sen. et jim. in their opinion, that in high 

 latitudes the temperature of the soil is higher than that of the 

 air. They estimate the temperature of the soil at Berlin and 

 Potsdam at 50°.07 to 50M5, and consequently find, as Hum- 

 boldi and Tralles ascertained the mean temperature of Berh'n 

 to ])e 46°.4 to 47°.'3, that there is a considerable difference be- 

 tween their results. 



If the mean temperature of the soil can only be arc3rtained 

 from the coldest springs (provided there be no high mountains 

 in the vicinity which could send down cold springs into the val- 

 leys), and if, without exception, ail constant, or nearly constant, 

 springs are thermal, then even the Louisenbrunqen and the 

 spring at Templin must he thermal. With regard to the latter 

 it is the n>ore probable, as it is indebted for its existence not 

 only to the meteoric waters of the neighbouring hills, but seems 

 to take its rise at a much greater distance. The mean tempera- 

 ture of the earth at Berlin is therefore probabU below 49M, so 

 that the difference is considerably diminished, if not totally an- 

 nulled. The difference of 2^°, mentioned by Erman, between 

 the temperature of the springs in Freienwald and at Neustadt 

 is also a corroboration of this opinion. 



From the six years' observations made at Stuttgart on the 

 temperatures of the air and of the springs, it was found that 

 the mean of the latter only surpassed that of the former by 

 0.°4*27. It must, however, be ol)served, that the mean tempe- 

 rature of the air was determined too high, on account of the 

 want of observations made during the night ; but then, on the 

 other hand, that of the springs must also have been estimated too 

 high, as the observations were made at the time of the daily 

 maximum tem}:crature of the atmosjhiTc, and as the wooden 

 aqueduct, wh'cli is about a mile in length, lies at a depth of only 

 three feet, and in several places i j made to pass through brooks. 

 And if the influence of the daily variations of temperature be no 

 • Ibid. vol. XV. p. 1C3. 



