On Underground Temperatures. Table I. 



Depths 

 below 

 surface. 



Feet. 

 300—360 

 480—540 

 600—660 

 720-780 

 780—840 

 840—900 

 540 (a) 



20 



38 

 597 

 630 

 325 (a) 



29 

 351 

 561 

 930 



1440 



768 



100§ 



200 

 400 

 600 

 650 

 1584 

 460 

 329 

 205 

 787 



1033 

 1073 

 2038 



361 



568 



568 

 1312 

 1656 



YI 



Tempera- 

 ture at 

 depths. 



Fahr. 



YII 



Refekences and Remarks. 



Ibid. All these are air temperatures. 



(a) Eecorded by J. T. Price. 



Cordier, " Essai sur la Temperature de l'lnterieur 

 de la Terre," 1822. Temp, of the air in galleries 

 at Carmeaux 23 '5° C., and at Littry 21° C. 



(a) The mean surface temp, was estimated from 

 shallow wells adjoining the coal pits. 



R. YV. Fox, " Trans Roy. Soc. Cornwall," vol. iii, 



p. 313, (1828). 

 (a) Air 80.° 



De la Rive and Marcet, " Mem. Soc. Phys. G-eneva," 

 vol. vi, p. 503 (1833). Thermometer protected 

 against pressure. This depth is equal to 713 

 English feet. 



Phillips, "Phil. Mag.," vol. vi, p. 446 (1834). 

 Arago, " Notices Scientifiques," vol. iii, p. 347, et seq 

 (a) Overflowing spring. 



Arago, "Not. Scient.," vol. iii, p. 347 et seq. 

 (a) Recorded by Humboldt. 



(5) Temp, of Boehum, which is one degree further 

 south, is 48'6°. The boring was ultimately carried 

 to a depth of 2113 feet. 



(c) No reference given. 



Walferdin, " Comptes rendus," 1836, p. 314.** 



Walferdin, " Comptes rendus," 1837, p. 977 ; and 

 Araero. 



agree with the temperatures at depth (which are those given here) owing probably 

 to the influx of water at intermediate depths. 



** All Walferdiu's observations were made with overflow thermometers pro- 

 tected against pressure. 



ft Temp, of Paris. Another datum line of invariable temperature (53° F.) at the 

 depth of 28 metres (92 feet) in the cellars of the Paris Observatory, is sometimes taken. 



