18 EEM.UtKS OX TE5IPEEATURE OF THE EARTH IN MINES. 



ventilation provided ; tlie temperature would" therefore be much 

 above the normal condition, it was78degs, ; and at 1200 feet 

 two men were at work 150 feet in from the shaft (three shifts are 

 kept at work) ; the thermometer here stood at 80 degs. It may 

 reasonably be assumed that a current of air strong enough to 

 carry off the heating effects of the workmen and their lights 

 would cause a great decrease of heat at these greater depths. 



At the Great Monkland, 9 h. 45 m. a.m., 28th March, rain 

 had fallen, the air was moist, sua clouded, weather dull, 

 thermometer 74 degs. in the shade. Two men were working in 

 the bottom, the centering being 35 feet above them, three shifts 

 are kept at work, consequently, with no artificial ventilation, the 

 temperature would be abnormally high. At the 240 feet level 

 a strong current was passmg through to another outlet, and the 

 thermometer indicated 64 degs. ; this is 2 degs. less than on the 

 previous occasion, as were those m the Golden Crown shaft, 

 except that in the bottom, which was the same. At 650 and 

 900 feet, thermometer 72 degs.; at 1400 feet it indicated 75 degs.; 

 and at 1490 feet, 78 degs. Here again the avoidable causes of 

 heat more than accounting for the trifling increase in the bottom 

 of the shaft over that at the surface, although that was 30 degs. 

 less than the shade temperature in our hottest days of summer,, 

 and at least 50 degs. below the temperature of our summer's 

 sun, under which many out-door workers pursue their avocations. 



At the Inglewood ^line at noon of same day, the 

 thermometer stood at 71 degs., the weather having become 

 inordinately cold ; 71 degs. in the shade at noon being most un- 

 usual in March. Showers were falliiig occasionally. At 350 feet 

 and 620 feet down the shaft the thermometer showed 72 degs., and 

 at 1,200 feet, 75 degs. Two men were working m a cross-cut from 

 the shaft, 370 feet distant. The shaft was centered to the bottom 

 but no division in the cross-cut ; the temperature at the face 

 was 92 degs., so that the bottom of the shaft would be affected 

 by this heat, which with a fair current of air would be dissipated 

 rapidly, leaving the normal temperature as low as in any portion 

 of the shaft. 



On 2nd April, when the weather had assumed a somewhat 

 normal condition, the temperature, at 1 p.m., in the shade 



