52 REPORT—1904. 
Mons. L. Possigue, in the ‘ Bulletin de la Société de l’Industrie Minérale’ 
for 1903. The first 764 metres belong to the New Red Sandstone series, 
including Lias and Permian. The remainder include 112 m. of Upper 
Coal Measures, 66 m. of Lower Coal Measures, and 68 m. of Schists. The 
following rock temperatures were observed during the sinking :— 
Depth Temp. C. Depth Temp. C. Depth Temp. C. 
M. o | M. 2 M. 2 
10 10°5 830 39°6 930 44°6 
300 21:0 850 10°7 950 45:2 
400 24:5 860 41:0 960 45°5 
600. 31°1 870 41°5 970 45-7 
700 34:2 890 42-9 990 46°4 
750 36°8 900 43°5 1000 46°8 
800 38°3 910 43°8 1009 47-4 
The shallowest, compared with the deepest, gives an increase of 
36°:9 C. in 999 m., which is at the rate of 1° C. in 27:1 m.,, or 1° F. in 
49-4 feet. 
When the observations are plotted they show nearly a straight line 
from 10 m. to 600 m., its gradient being 1° C. in 28-6 m. (1° F. in 52 feet), 
and the remaining portion from 600 m. to 1,009 m. oscillates about a line 
whose gradient is 1° C. in 25-1 m. (1° F. in 46 feet). 
Regular observations of temperature have been taken in the Simplon 
Tunnel, of which only about half a kilometre remains to be pierced. On 
its completion Mr. Francis Fox promises a full account of the tempera- 
tures, which will probably be communicated to one of the London societies 
before the end of the present year. 
A large body of evidence on temperatures in deep coal mines is con- 
tained in the report recently published by the Royal Commission on 
Coal Supplies. The chief element of uncertainty in discussing the observa- 
tions is the mean surface temperature, which has in most cases not been 
directly observed, and is doubtful to the extent of 1° or more. The 
following list of well-determined mean surface temperatures (chiefly from 
the publications of the Royal Meteorological Society) seems to constitute 
the best material for forming a judgment. They are for . moderate 
elevations, except where otherwise stated :— 
Camden Square, London : : : : é > AGS? 
Bolton . : ~ : : . - 49P2 
North Thoresby (Line.) , ; ‘ : . ‘ .  G49P2: 
Rounton (North Yorks.) z . ¥ » AFP 3: 
Ashton-under-Lyne (elevation 405 feet) - : -, £OaD 
At Pendleton, near Manchester, Mr. H. Bramall took observations 
in the Rams mine and in the Agecroft Colliery. The deepest observation 
was at 3483 feet from the surface in the Rams mine, the temperature 
found being 100°, as shown by a thermometer left for three hours in a 
hole bored 35 feet into the rock and covered with a piece of cotton waste. 
Assuming a surface temperature 47°, we have an increase of 53° in 
3,483 feet, a: 1° in 66 feet. If we take the surface temperature as 48°, 
it is 1° in 67 teet. 
At Agecroft Colliery the deepest observation was 92°°5 at 2,940 feet ; 
which with an assumed surface temperature 47°°5 gives 1° in 65 feet. 
The above-named temperature in the Rams mine was checked by 
