on Hot and Thermal Springs. 345 



Schneider at Strasbourg also found, from thermomctrical obser- 

 vations at a depth of 15 feet, that, in the years 1821 and 1822, 

 the maximum took place in September, and the minimum in 

 February ; but in 1823, the maximum happened already in 

 August, and the minimum in January. Muncke observed the 

 maximum in a thermometer sunk five feet deep into the earth 

 during the years 1821-1826, twice in September, twice in Au- 

 gust, and once in July.* 



Direct observations on the temperature of the soil have been 

 made by sinking thermometers of different lengths into the 

 ground, by Ferguson at Abbotshall'm Fife, Scotland ,f by Rud- 

 berg in Stockholm, I and by Quetelet at Brussels, § the results 

 of which are given in the following Table : 



* Gehler's Neues Worterbuch, vol. iii. p. 988. 



t Ure's Chemical Dictionary. From the anomalous result of the July ob- 

 servation on the thermoineter situated at a depth of three feet, of which no 

 trace is to be found in any of the rest, it seems that either an error in the ob- 

 servation or a misprint must have crept in. For which reason Kamtz 

 (Lehrbuch der Meteorologie, vol. ii. p. 183) adopted as the actual observa- 

 tion the number 8°.65, which he obtained from a formula derived by hiui from 

 observation, and thus obtained for the greatest yearly difference of tempera- 

 ture 1 1°.99. 



X Poggcndorft'a Annal. vol, xxxiii. ]i, 25). 



§ Ibid. vol. XXXV. p- 139, 



