ANALYSES OF AIR FROM COAL MINES. 57 



Sample No. 3 taken from No. 32 A bord, being the fifth from 

 the return end of the split. Time 12*55 p.m. Temperature 

 79 degrees F. 



Sample No. 4 taken from No. 6 bord, Merewether's east boun- 

 dary crosscut district. Time 1-30 p.m. Temperature 78 degrees 

 F. Air current about 7,500 cubic feet per minute for 44 men, 4 

 boys and 4 horses, or 105 cubic feet per minute for each individual. 



Analyses of samples from Burwood Colliery. 



Oxygen 



Carbon dioxide 

 Nitrogen 



1. 



20-42 



0-08 



79-50 



2. 

 20-77 

 004 

 79-19 



3. 



20-83 



0-07 



4. 



20-34 



0-13 



79-53 





100-00 



100-00 



0-13 

 0-01 



100-00 



Deficiency in oxygen 

 Excess of CO o 



0-48 

 0-06 



0-56 

 0-10 



Carbon monoxide and marsh gas were absent in all cases. 

 Marsh gas was tested for in the mine by means of Clowes' hydrogen 

 lamp. The determination of carbon dioxide in sample No. 3 was 

 unfortunately spoilt owing to an accident, there being insufficient 

 of the sample to repeat the experiment. The amount, however, 

 was certainly no greater than was found in No. 2. 



In the case of samples 2 or 3, the air cannot be said to be con- 

 taminated at all, and is practically as pure as the air in the streets 

 of a town. In the other samples there is an excess of carbon 

 dioxide and a deficiency of oxygen when compared with ordinary 

 air, but not sufficient to produce ill effects upon anybody breathing 

 it. 



Samples of Air from Gunnedah Colliery. 

 On the 10th May, 1900, a tire was discovered in this colliery, 

 about 200 yards from the tunnel mouth, in consequence of which 

 it was decided to seal it off, in order if possible, to extinguish the 

 fire. Whilst this was being done, an explosion took place, injur- 

 ing several men engaged in the work of building stoppings, etc. 



