446 MriMoyle on the Temperature of Mines. [Dec. 



sailing, combined with the proper capacity for stowage, is of no 

 less importance. At no antecedent period did so many ships 

 navigate the uncertain bosom of the deep. Every nation almost 

 is aiming at a maritime character, and the sea is become one of 

 the high roads of civilization. To the first maritime people on 

 earth, the improvement of naval architecture addresses itself 

 with peculiar force, and with higher claims to attention, than 

 any other. George Harvey. 



Article IX. 



On the Temperature of Mines. By M. P. Moyle, Esq. 



(To the Editors of the Annals of Philosophy.) 



GENTLEMEN, Hclston, Oct. 30, 1824. 



In consequence of my having communicated to the Annals 

 some experiments and remarks on the temperature of mines, 

 involving the disputed subject as to the natural heat of the in- 

 ternal strata of the earth, I conceive that your readers are 

 entitled to whatever additional proofs I may be enabled to 

 advance in support of my original opinion, although it forms 

 the substance of a paper read before the Royal Geological 

 Society of Cornwall at their last anniversary meeting. 



Perhaps the minds of most of your readers have been made 

 up as to the probability of one cr the other theory, de- 

 duced from the experiments already detailed in the Annals, 

 and which have been tried in this county within the last two or 

 three years. I shall in the first instance endeavour to prove the 

 dubiousness of the one conclusion in a tenfold degree over that 

 of the other, for the high temperatures observed at the bottom 

 of mines, must be, and indeed is, acknowledged on all sides, 

 much influenced by local causes, not easily got rid of, or allowed 

 for ; whereas, on the other hand, the low degrees of heat some- 

 times met with, seems to be beyond the pale of uncertainty ; and 

 if we can adduce a solitary instance only of temperature not 

 exceeding the annual mean of the climate, at a considerable 

 depth below the surface of the earth, and more particularly 

 beneath the level of the sea, I shall be apt to infer a difficulty 

 insurmountable by my opponents. 



I would suggest that in all endeavours to elucidate this sub- 

 ject, our main object, in proving the correctness of either theory, 

 should be in obtaining the coldest situations possible, instead of 

 those possessing a high temperature, for the presence of work- 

 men, the boring and blasting of rocks, the burning of candles, 

 &c. together with the lengthened column of the atmosphere, 

 must much influence the latter cause, while no operation with 



