r ve ‘On the Temperature of the Mines in Cornwall, . 203 
At 160 fathoms the thermometer stood at 70° 
*. 180 
190 
at that period the bottom of the mine. 
__ At the several stations (or levels) where.I placed the thermo- 
meter to settle, a stream of water comes through the vein (lode) 
and is conveyed to the engines; and on.immersing the ther- 
e 
' 
110 
120 
140 
160 
180 
190 
do. 
do. 
do. 
do. 
do. 
do. 
do. 
ee ee ee 73 
6 ae 79; which was 
mometer in it, I found the temperature to be as follows; viz. 
At 100 fathoms GS° in the cistern at the engine shaft, where 
the water from this level is mingled with 
the water from the bottom of the mine. 
64 in the stream issuing through the level. 
65 do. 
68 do. [per ore. 
73} do, issuing through a vein, rich in cop- 
74° do. do, 
74 = do. 
74 = do. 
I next proceeded to ascertain the temperature in those parts 
of the miue where the labourers were at work; and which is at 
a distance of 15 to 30 fathoms from any cur rent of air or of any 
100 
110 
120 
: 130 
: 140 
150 
160 
170 
180 
do. 
do. 
do. 
do. 
do. 
do. 
do. 
do. 
do. 
~ of the working shafts, and obtained the following indications: 
At 90 fathoms 74° the vein dry, but rich in ore. 
70 do. but poor, 
72 do. do. 
734 do. do. 
742 do. do. [not rich. 
7& do. containing ore in the vein, buf 
78 do. but poor, [other ores, 
80 do, the vein rich in copper, and 
784 do. but poor, 
78 a considerable quantity of water dropping 
_ from the roof of the working, and issuing from other parts of 
the vein which is rich in copper ores. 
~ On the 13th of December 1815 I repeated my experiments, 
and the results were as under ; viz. 
At the surface in the open air 50° 
3 fathoms under the surface 52° 
20 
do. Se se 57 
do. Fi 61 
do. Se ae 63 
do. os Ce 63} 
(lo. es ia 64 
do. oe Si 66 ? 
do. 7 ae 68—wwater 64° 
do. ; . 70 yf 
At 
