SUMMARY OF DATA 707 



from 36 to 38 degrees, so that the depths from the surface, which varies 

 not over 100 feet, are about 6/lOths (0.6) of the depth down the shaft. 

 . It will be noted that the air at the bottom varies not over 3 degrees 

 Fahrenheit from the rock and water temperature, even when there is a 

 wide range in the surface temperatures, and that it is practically satu- 

 rated, even when much warmer than the air outside, showing the evap- 

 oration that goes on and makes the mine dry and even dusty, although 

 there is moisture in the rock. The bottom temperature of 56 degrees at 

 something like 1,400 feet vertical depth beneath the surface is what might 

 be expected. 



