GARFORTH : DEEP MINING. 
473 
air conies in contact witli a large area of freshly wrought coal at long- 
long distances from the shaft. When a large volume of fresh air is 
passing through tlie mine, it is considerably influenced in lowering 
the temperature, but at long distances in-bye, and where coal roads 
exist, the cooling effect of tlie ventilation is small. As the air in 
circulation is gradually increased, so the temperature of the strata is 
reduced by the absorption of heat from it. Evidence was given 
before the Commission of the temperature endured in the stoke-holes 
of steamers, and places where glassblowers work. In some cases 
labour liad been carried on where the thermometer indicated 180 
degrees, but in such cases it was radiated heat and did not accurately 
indicate the temperature. It was also proved by the experience 
obtained in foreign climates that a temperature of 125 degrees in the 
shade was more endurable by reason of the dryness of the air than 
moist air of 86 degrees. In certain cotton mills the temperature 
often exceeds 90 degrees, and in this atmosphere some operatives are 
engaged for ten consecutive hours. The depth stated by the Com- 
mission at which the temperature of the air would amount to 98 
degrees, or blood-heat, was about 3,000 feet. From experiments 
conducted by medical men and scientists it has been shown that at 
a temperature of 84 degrees Fahr. workmen are not inconvenienced, 
and can continue their occupation for years without interruption. 
Complaints of languor are, however, made. From 100 to 110 degrees 
tliis feeling is increased, and manifests itself in diminished muscular 
power, resulting finall)^ in further muscular disturbance and paralysis 
of the heart. It has also been proved by experiment that man's 
skin is better adapted and can withstand a greater heat than certain 
animals. This is due to increased respiration, circulation, and eva- 
poration, by which the body is prevented from rising above the 
natural temperature. If a man's body couldnot lose by evaporation, &c., 
the heat which may be produced within him it would intensify and 
result in death. 
As regards increased barometric pressure, some men are capable 
of bearing a pressure of 38 or 40 inches of mercury without serious 
results, and medical men are of opinion that increased pressure is not 
likely to reduce the powder of enduring increased temperature, or that 
it will affect evaporation. 
