/•esperfing the Temperature of Mines. gg 



present, from the Annals of Philosophy for December last, 

 p. 440. 



" The high temperature which prevails in mines having 

 excited some attention, I am induced to submit to the Corn- 

 wall Geological Society, the result of further observations, 

 which have been made on the subject in several mines since 

 my last communication." (Phil. Mag. vol. Ixi. p. 350.) 



" At South Huel Towan Copper Mine, in the parish of 

 St. Agnes, the temperature of the water in the cistern at the 

 " sump" or bottom of the mine (45 fathoms deep), was 60°. 

 This may be taken therefore as the mean temperature of the 

 streams of water which flow through the deepest levels, or 

 galleries, into the cistern. — Two men were employed at one 

 time, that is, 8 in 24 hours in this part of the mine." 



" East Liscomb, a copper mine in Devonshire; depth 82 

 fathoms ; temperature of water in the cistern 64°." 



" Huel Unity Wood, a tin and copper mine in Gwennap pa- 

 rish; depth 86 fathoms; temperatm-e of water taken as before, 

 64°. Four men constantly worked at the bottom of this mine." 



" Beer Alston, a lead mine in Devonshire; 120 fathoms 

 deep; water 66*5° of temperature, taken as before." 



" Poldice, a tin and copper mine in the parish of Gwennap ; 

 temperature of the water 78° in the lowest cistern in one shaft, 

 which was 144 fathoms deep. — Eight men were constantly 

 employed at a time at the bottom of this part of the mine, 

 besides two men during the day (" ore tribute"). The tem- 

 perature of the water in another shaft of the same depth, and 

 tried in the same way, was 80° : two men only were employed 

 at a time in the levels at the bottom." 



" Consolidated copper mines in Gwennap. One shaft is 

 150 fathoms deep, and the temperature of the water 76'': six 

 men were employed at a time at the bottom. The tempera- 

 ture of the water, ascertained in the same v.aj', in another 

 shaft of the same depth, was 80° ; and here there were eight 

 men at work at a time." 



" Huel Friendship, a copper mine in Devonshire. Tem- 

 perature of the water taken as above, was 64*5° at tlie depth 

 of 1 70 fathoms. The number of men employed at the bottom 

 has not been repoiled ; but as they were sinking the engine 

 shaft, there could not be less than two. There is, when its 

 depth is considered, a very small quantity of water flowing into 

 the bottom of this mine ; for it requires only a six-inch box, 

 and five strokes of the engine a minute to draw it up. The 

 mine is situated on very elevated ground bordering the gra- 

 nite hills of Dartmoor. Although the temperature ol' the wa- 

 ter is probably more than 14° above the mean of the climate 



