238 Mr Hcnw(X)d on the temperature of Mines. 



more so than the air which surrounds them.''* The truth of 

 this assertion will be seen from the following comparison of 

 the temperatures of air and water in various mines, and at 

 different depths. 



Place. 



Little Bounds Mine, 



Huel Vor, i 



Little Bounds, 



Wellington, 



Botallack, 



Ding-dong, 



Chacewater, 



Huel Vor, 

 Huel Abraham, 



Stray Park, 

 Dolcoath, 



240 



80 



r80 



(82 



It is admitted by all parties, that the temperature of such 

 parts of mines as are wrought by many men without a free cir- 

 culation of air, is somewhat above that of the water, and of 

 the air in properly ventilated stations, excepting, perhaps, at 

 or near the bottom of deep mines, notwithstanding the influ- 

 ence which the copious ascent of vapour constantly obtaining 

 must exert in diminishing the temperature of the lower por- 

 tions, and elevating that of the shallow ones. On examining 

 the directions of the aerial currents in 25 of the principal 

 shafts of Dolcoath mine, Mr Rule found them to be descending 

 in 13, and ascending in the others. But a change in the 

 direction of the wind reversed that of the currents in some of 

 the shafts, and other parts of the mine. Having been favoured 

 with a sight of some of Mr Fox's communications to a scien- 

 tific friend on this subject, I am permitted to make some in- 

 teresting extracts relative to the influence of the seasons on the 



