448 



Prof. Phillips on Subterranean Temperature, 



which nevertheless drops, but not in great quantity, down the 

 sides. This water falls several yards below the coal seam in 

 which our experiments took place, into the bottom of the pit, 

 which is to be carried considerably deeper to a lower bed of 

 coal. 



On arriving at the point a, we entered on the nearly level 

 floor of the coal, and found four narrow headings driven short 

 distances E., W., N., and S. Strong currents of air were 

 established along the headings to sweep the fresh face of coal, 

 from all points of which the carburetted hydrogen gas was 

 heard to issue with a faint tinkling or humming noise, like 

 that which might arise from the vibration of innumerable 

 very small kettles. This gas was carried off too rapidly by 

 the currents of air to permit any exhibition of phenomena de- 

 pending on its inflammable properties, even when the Davy- 

 lamp was placed in angles of the front of the coal. 



By the care of Mr. Foster, the intelligent viewer, a hole 

 was drilled in the floor of the coal seam on the dip side (east) 

 to the depth of two feet ; and when Mr. Wharton and I reach- 

 ed the seam, this hole was completed, and full of salt water. 

 This station is marked A on the accompanying plan ; it is 

 22 yards from the pit. 



~ B C D 





PPBIK 



5. The first experiment was made by my going instantly to 

 the bore-hole A, and trying the temperature of the water 

 which had risen in it. By most careful observations it was 

 found to be 70' 1. The air in the drift was generally 62°; 

 this was the temperature of the air in the porch G : it pre- 

 vailed also along the drift E, in which no one was at work, 

 till near the forehead, when it rose to 64°, and close to the coal 

 among the humming gas, which would not fire, it was 68°. 



