522 



Mr. Fox on the Temperature of 



Rock. 



Depth in 



fathoms 



Ore worked 

 in Mines. 



Brought over 



United Mines C. K. .. 170 



Huel Friendship C 170 



Bulb of 

 therm, in 



2091 



Poldice C.&T. 



Ttngtang C. . 



Cook>kitchen T.&C 



United mines C. . 



Huel Abraham C. 



Stray Park 



Eastern end of level 



Western do. 



K. 

 K. 

 G. 

 K. 



}. 



176 



178 

 190 

 200 

 200 



200 

 200 



w. 



Temp. 



1074°-5 

 76 

 64-5 

 99 



82 

 68 



88 



78 



72 

 74 



Date of Ob. 



servation. 



1819. 

 1822. 

 1830. 

 1830. 

 1815. 

 1820. 

 1815. 



1827. 

 1827. 



3775 1776 

 19 Mines, or 24 Stations : mean depth 157"3; mean temp. 74. 



Mean temp, of climate .. .. 50 feet. 



Excess 24°= Pin 393 



If some of the foregoing results, which differ much from 

 the mean temperature, were omitted, the ratio, instead of 1° 

 in 39*3 feet, would be 1° in 43 feet, at least. 



Mines from 201 to 300 fathoms in depth. 



HuelVor T. 



Levant ...T.&C. 



Dolcoath T.&C. 



Bottom of Shaft ., 



Near the end of deepest"! 



level, thermometer ? [ 



feet deep in rock, du- f 



ring 19 months y j 



Bottom of Shaft 



Tresavean C. , 



Consolidated mines C. , 



G. 



G. 



G. 

 G. 

 K. 



230 



230 



239 

 254 



w. 

 r. 



3 feet deep in the rock in a cross level I 



and 24 fathoms from the lode J 



• In the lode 3 feet deep 



290 

 1972 



5 Mines, or 8 Stations : mean depth . . 246*5 

 Mean temp, of climate 



82 



76 



82 

 76 



85-3 



92 



652-3 



81-5 

 50 



1815. 



1822. 



1819. 

 1837. 



1837. 



1837. 



Excess.. . 31°-5 =l°in 47 ft. 

 or, omitting the last station, at 92° of temperature, the ratio would be 1° 

 in 48 feet. 



If, instead of making the calculation from the surface down- 

 wards, it had been commenced at 10 or 15 fathoms under 

 it, where the temperature may be supposed to be nearly 

 constant, and coincident with the mean temperature of the 

 climate, it is evident that the diminishing ratio of the aug- 

 mentation of heat as the depth increased would be rendered 

 still* more remarkable. On the other hand, the vicinity of 



