BY WM. FKYAR, INSPECTOR OF MINES, QUEENSLAND. 17 



blasting, and the temperature was here found to be TOdegs., 

 somewhat cooler than the coolest place on the surface at 8 

 o'clock in the morning of a dull day. At 650 feet in a recess in 

 the shaft the temperature was 71 degs. ; and at 240 feet, where 

 communication is opened with another shaft, and to which a 

 strong current of air was passing through, the temperature was 

 66 degs., that at the surface having risen by this time (10 a.m.) 

 to 86 degs. ; so that the effect of this 240 feet of rock on a good 

 current of air passing was to cool it by at least 20 degs., but the 

 difference between it and the exposed air at the surface would 

 be from 40 degs. to oO degs. 



Observations were made on the same day at the No. 3 and 

 4 North Glanmire Company's mine, which is not a deep mine. 

 The temperature at the surface was 86 degs. at 11 a.m., that at 

 160 feet down, 75 deg., in a recess in the shaft, and at the 

 bottom (339 feet), where communication is made with an ad- 

 joining mine, it was also 75 degs. No perceptible current of 

 air was travelling. 



It will be observed that, notwithstanding the taking of the 

 temperature at the coolest part of the day and in the shadiest 

 place to be found on the surface, in all cases that of the shaft at 

 whatever depth tried, was lower — -generally much lower — than 

 the temperature at the surface. But by far the coolest place 

 was where a good current of air was passing through to another 

 mine, shewing, I think, that at lower levels a similar cause 

 would produce a like effect. 



The next series of observations was taken on 27th and 28th 

 March, and on 2nd April, 1889. The temperature on the sur- 

 face was in all cases taken in the most shaded place obtainable 

 near the mine. The weather was dull and cold for the time of 

 the year. In some cases rain was falling, and had fallen during 

 the previous night. At the Golden Crown the first observations 

 were taken, date 27tli March ; time, 3h. 30m. p.m.; ther- 

 mometer, 77 degs. At the 240 feet level, 76 degs., no current 

 passing except that in the shaft, which was imperceptible. At 

 the 830 feet level, 77 degs. ; no men were at work at either of 

 these levels. At the 930 feet level two men were working, 150 

 feet in from the shaft, three shifts are kept on. and no artificial 



