ANALYSES OF AIR FROM COAL MINES. 53 



that proportion, but with as much more as the inspector shall 

 direct) shall sweep along the airways and be forced as far as the 

 face of and into each and every working place, where man, boy or 

 horse is engaged or passing, main return airways only excepted." 



The quantity of air was not called in question, and in order to 

 test the quality in the return airway used as a travelling road, 

 samples wei e collected as follows : — 



Sample 1. From the Lambton heading return near the double 

 doors, 184 yards from the engine plane. Time 3*50 p.m. Tem- 

 perature 70 degrees F. Quantity of air passing 18,700 cubic feet 

 per minute. This return airway receives part of No. 2 split, and 

 the whole of Nos. 3 and 4 splits, and before passing through the 

 working places comes down the Centennial shaft. It travels over 

 142 men, 14 boys and 14 horses, and consequently each man, boy 

 and horse when travelling in this return at this place would 

 receive 110 cubic feet per minute, if they were all in the return 

 at the same time. The measurement of air was made about 100 

 yards from where the sample was taken. 



A second measurement of air was made about 200 yards inbye 

 (further into the workings) from the first measurement, and gave 

 25,280 cubic feet per minute, or 148 cubic feet for each man, boy 

 and horse. 



Sample 2. This was taken on another day in the place where 

 the first measurement of air referred to above was taken, namely, 

 about 100 yards inbye from where sample No. 1 was taken. 

 Time 1 p.m. Temperature 72 degrees F. Quantity of air 19,320 

 cubic feet per minute, or 114 cubic feet for each individual. 



Sample 3. This was taken on the inbye side of cross-cut, about 

 200 yards inbye from where sample No. 2 was taken. Time 1*45 

 p.m. Temperature 72*5 degrees F. Quantity of air 24,200 cubic 

 feet per minute, or 142 cubic feet for each individual. 



Sample 4. This was taken near the junction of Nos. 3 and 4 

 splits and about 300 yards from the working places. Time 2-10 

 p.m. Temperature 74 degrees F. The shade temperature at the 

 surface taken at 3'30 p.m. was 75 degrees F. 



