Miscellanies. 397 



Extracted and translated by Prof. J. Griscom. 



22. Progressive increase of the Internal Heat of the crust of 

 the globe. — For the purpose of ascertaining whether a constant 

 stream of water could be obtained by means of an Artesian well, 

 sunk on the south side of the Jura mountains, at the distance of 

 about a league from Geneva, and at an elevation of two hundred 

 ninety nine feet above the level of the lake, M. Giroud at his 

 country residence at Pregny, bored to the depth of five hundred 

 forty seven feet without success. Despairing of success, he offered 

 great facilities to any persons who might wish to prosecute the en- 

 terprize, for the purpose of scientific enquiry. 



On this occasion, M M. Aug. De La Rive and F. Marcet made 

 a successful application to the friends of science, and also to the gov- 

 ernment, and funds were obtained sufficient to enable them to con- 

 tinue the operations during eight months, and to extend the boring 

 to the depth of six hundred eighty two feet. The hole bored,, was 

 about four and a half inches in diameter. Water began to appear 

 in it at the depth of twenty feet, and it is worthy of remark, that 

 the height at which the water stood in the opening, as measured 

 from the surface, was lower when the greatest depth was attained 

 than it was at half the depth. At two hundred seventy five feet of 

 depth, the water stood at fourteen feet from the surface ; — at five 

 hundred feet it sunk to twenty two feet — at five hundred fifty, to 

 thirty five feet. It then rose. At five hundred ninety five feet, it 

 stood at twenty four feet six inches, but at six hundred seventy five 

 feet, it again sunk to thirty five feet eight inches. The result of 

 this praise worthy effort must operate as a salutary preventive from 

 any farther expensive attempts to obtain running fountains from the 

 theory of an internal communication with the springs on the sum- 

 mits of the Jura. 



Having attained the extraordinary depth above mentioned, the 

 experimenter devised the means of ascertaining the temperature of 

 this opening at difi:erent depths. As the common thermometer 

 would not answer the purpose, they contrived a self registering ther- 

 mometer, constmcted on a large scale, and whose accuracy was sub- 

 ject to the most satisfactory tests. 



The following table exhibits the temperature of the liole at the 

 depths specified. 



