TRANSACTIONS OF THE SECTIONS. 



53 



Remarks on the Temperature of the Earth's Crust, as exhibited by Thermome- 

 trical Returns obtained during the sinking of the Deep Mine at Bul-infield. 

 By Wm. Fairbairn, Esq., LL.D., F.R.S. 



It is now more than ten years since a series of experiments were commenced to 

 detennine the temperature at which certain substances became fluid under pressure. 

 These experiments had reference to the density, point of fusion, and conducting 

 power of the materials of which the earth's crust is composed, and were prosecuted 

 with a view to the solution of some questions regai'ding the probable thickness of 

 the earth's crust. Contemporaneously with these, we were fortimate in being able 

 to ascertain by a series of direct experiments, imder very favoui-able circumstances, 

 the increase of temperature to a limited depth in the earth's crust itself These 

 observations were obtained by means of thermometers placed in bore-holes at various 

 depths, during the sinking of one of the deepest mines m England, namely, the coal- 

 mine belonging to F. D. Astley, Esq., at DuMnfield. The bore-holes were driven 

 to such a depth as to be unaffected by the temperature of the air in the shaft, 

 and the thermometers were left in them'for periods varying from half an hour to two 

 hours. It is very difficidt to arrive at accurate data on the subject of the increase 

 of temperature as we descend from the surface to depths within our reach. On the 

 contrary, the experiments hitherto made, give unfortunately somewhat conflicting 

 results, and even in the same mine the rate of increase of temperature is by no means 

 imiform. This is shown very clearly in the results obtained by Mr. Astley. It is 

 scarcely probable, however, that the temperature in the mine shaft influenced the 

 results, and we must therefore seek the cause of this irregularity in the varying con- 

 ducting power of the rocks, ai'ising from different density, and different degrees of 

 moisture in the strata. 



The following Table gives the general results obtained dming the sinking of the 

 shaft, which extended over a period of nearly ten years, from Jime 1849 to March 

 1859. 



Table I. — Thermometric Observations in the Dukinfield Deep Mine. 



Date. 



1848. 

 July 28. 



1849. 

 June 1. 



„ 12. 



,, 16. 

 July 14. 



„ 16. 



» 27. 

 Aug. 9. 



„ 25. 



» 27. 



„ 31. 

 Nov. 14. 

 Dec. 6. 



„ 15. 



,, 22. 



1850. 



Jan. 9. 



„ 26. 

 Feb. 11. 



„ 19. 

 Mar. 5. 



Depth Temp*- 



of the rature 



Pit. of hole, 



yds. 



231 



234| 



237 



239 



240 



242 



244 



248 



248 



250 



252 



256^ 



262i 



270 



279| 



286i 

 293 

 300 

 309 



51 



57| 



58 



58 



b7i 



58 



57i 



58 



58 



57i 



57i 



58 



58 



58i 



58 



58i 

 591 



59| 

 b9i 



Time in 

 hole, in 

 minutes. 



m. 

 1440 



30 

 110 



60 

 120 

 120 

 120 

 120 

 120 

 130 

 150 



90 

 120 



90 

 140 



180 1 



110 



60 

 180 



70 



Quality of Measure, 

 or Strata*. 



Red rock 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue metals 



Blue shale 



Bituminous shale 



Strong grey warrant "1 



earth J 



Rock bands 



Hard mine roof 



Warrant earth 



Purple mottled shale . . . 



State of bore-hole, and other 

 remarks. 



No variation. 



Wet hole, water from sides. 

 Dry hole, water from sides. 

 Dry hole, water from sides. 

 Dry hole, water from sides. 

 Dry hole, water from sides. 

 Dry hole, water from sides. 

 Dry hole, water from sides. 

 Dry hole, water out of tubbing. 

 Dry hole. 

 Dry hole, in dust. 

 Dry hole, 5 men sinking. 

 Dry hole, 5 men sinking. 

 Dry hole, 5 men sinking. 

 Dry hole, 5 men sinking. 



Dry hole, 7 men sinking. 



Dry hole, 5 men sinking. 

 Dry hole, 5 men sinking. 

 Dry hole, 5 men sinking. 

 Dry hole, 5 sinking. 



* The terms in the column of remarks are those in common use amongst the miners. 



