THERMAL CONDUCTIVITIES OF ROCKS 289 



protective cover against the loss of heat. This suggestion would also 

 explain the increase of temperature and the accumulation of heat along 

 the faults as it is possible to suppose a stronger increase of temperature 

 in the direction of the dislocation in the strata. This suggestion is 

 strengthened by the fact that the especially high horsts are characterized 

 by temperature maxima on the isothermal map.' 



A map of the Northern Pechelbronn oil-fields showing the temperature 

 curves at a depth of 400 m. and their relation to productive oil zones, as 

 well as three cross sections of the oil-fields showing underground tempera- 

 ture curves, are given. 



A list of publications on temperature measurements is attached. 



The Temperature of Deep Waters in the Region of Paris. 

 By P. Lemoine and R. Nassans. 



Bulletin du museum national d'histoire naturelle, series 2, vol. 1, no. 4, May 



1929, pp. 264-280. 



In this article the authors sum up a series of data obtained on thermo- 

 metric measurements of deep waters in wells bored in the region of Paris. 

 They consider these data to be of interest, notwithstanding the lack of 

 certainty that the temperatures taken are sufficiently accurate. 



After a brief description of the process by which the geothermic degree 

 (Dg) should be calculated and the influence of the possible errors on its 

 value established, the authors give some data concerning the variations of the 

 geothermic degree in different places, as determined by the following 

 scientists : 



Gensanne, who made experiments in 1740 near Belfort, found, according 

 to Becquerel : 



At a depth of 101 m. . . . 12-5° 



,, 206 m. . . . 13 -i° Dg. (101-206) = 17-5 m. 



,, 308 m. . . -19° Dg. (206-308) = 17-6 m. 



433 m. . . . 22-7° Dg. (308-433) = 33 -8 m. 



De Saussure (1785), who took measurements in Switzerland in wells 

 bored in searching for rock salt, obtained these measurements : 



At a depth of 108 m. ..... 14-4° 



183 m i S -6° 



,, 220 m. . . . . .17-4° 



Corder calculated the geothermic degrees (Dg) given for the following 

 places : 



Cormeaux ....... Dg = 36 m. 



Littry ....... Dg = 19 m. 



Decize ....... Dg = 15 m. 



By comparing a series of data taken in the wells in Paris and its vicinity, 

 the authors found the mean value of the geothermic degree for the basin 

 of Paris to be 34 m. 



Great anomalies were observed in Pressagny-l'Orgueilleux. The tem- 

 peratures of waters at a depth of 70 m. were found to be 17°, although 

 their normal temperature should be about 13 . 



The authors note especially that, by assuming one geothermic degree to 

 be equal to 34 m., the waters of a temperature of 17° should be at a depth of 



12 



