1823.] . On the Temperature of Mines, 445'^ 



My friend and relative, Joseph T. Price, of Neath, Glamor- 

 ganshire, has furnished me with the results of some observations 

 made last spring, in three collieries in the neighbourhood of that 

 place. The thermometer was buried for many hours from one 

 to two feet under the ground, at the bottom of each of these 

 colheries : in one of them, which was only 10 fathoms deep, the 

 mercury stood at 50° ; in another, 36 fathoms deep, it stood at 

 58°; and in the third, which was 90 fathoms deep, it stood at 

 62°. The difference between the first and last mentioned col- 

 lieries was 12°, which ratio nearly corresponds with that obtained 

 in our mines. 



It has been surmised that the heat noticed in the mines may 

 be attributed to the presence of metallic, and other inflammable 

 substances ; but when all the facts are considered, no causes, 

 merely local, can be imagined capable of producing such con- 

 stant, extensive, and powerful effects. If the water received its 

 heat from the metalhc veins, while passing through them, it 

 would surely become strongly impregnated with mineral sub- 

 stances ; — this is not, however, the case. I analyzed some from 

 the deepest part of Dolcoath, taken at 82°, immediately from 

 the copper vein, and obtained from a quarter of a pint of it only 

 half a grain of residuum, consisting of sulphuric acid, some oxide 

 of iron, and a little hme. I found a greater proportion of the 

 same substances in some water from a cross level, at a distance 

 from any vein, 200 fathoms deep, in the same mine. 



Water from the bottom of the United Mines, of the tempera- 

 ture of 82°, contained six grains of muriate of hme in a quarter 

 of a pint. Some water taken from the deepest parts of Tres- 

 kerby and Ting-tang, was, from the former mine, very shghtly 

 impregnated with sulphate of iron, and had a trace of muriatic 

 acid ; and that from the latter mine contained a very minute 

 portion of the muriate of lime. 



Since my last communication on the subject of the tempera- 

 ture of mines, I have had a thermometer, four feet long, placed 

 in a hole three feet deep, in a copper vein, at the end of the 

 deepest level, or gallery, in Dolcoath, which is 230 fathoms, or 

 1380 feet, under the surface ; a spot where no workmen were 

 employed, and where the current of air must have been small. 

 The hole was filled with clay round the stem of the thermometer, 

 so as to prevent the circulation of air near the bulb, and in this 

 situation it remained more than eight months. It was often 

 examined during that period, and was always found to indicate 

 a temperature of 75°, or 75^°, unless it had been recently over- 

 flowed by water. This happened several times, in consequence 

 of accidents to the machinery of the mine, and more than once, 

 the water filled the level for some weeks. As soon as it had 

 subsided, so as to permit access to the thermometer, the quick- 

 silver was observed to have risen to 77°, but in two or three days 

 it again fell to 75^°. 



