534 SUBTERRANEAN TEMPERATURE IN THE 



I. Observations made in Mines actually or but lately in 



OPERATION. 



1. At MilVs and ReecVs Mine, called the Creekpit, the tem- 

 perature was taken at three different levels, by plunging the ther- 

 mometer for some time into the water collected at the bottom of 

 the main shaft, and the shafts connecting the lower levels. The 

 amount of water accumulated at these points was very consider- 

 able, and the liquid was continually drawn off by the engine 

 and replenished from the galleries of the mines. The following 

 were the results : 



Depth. Temperature. 



318 feet, 59." 5 



375 " 61. 



420 " 63. 



2. Greenhole Pit. This is one of the comparatively shallow 

 mines at the margin of the field. When the observation was 

 taken there were but few hands employed in it. The tempera- 

 ture observed was that of a collection of water at the bottom of 

 the shaft, about a foot in depth. Result : 



Depth. Temperature. 



100 feet, 58." 



3. Engine Pit belonging to the Black Heth Company. The 

 air of this mine was obviously a good deal heated when the 

 workings were in active progress, and I therefore selected for my 

 observations a gallery remote from any present operations, and 

 in which no work had been done for som^ time. The ther- 

 mometer was immersed in a pool of water about IS inches deep 

 continually supplied from the neighboring strata. It was after- 

 wards inserted for some time into the rock of the floor, and with 

 the same result, which was — 



Depth. Temperature. 



412 feet, 63." 



The temperature of the water at the bottom of the main shaft 



