MINING CAMPS AND DYNAMITE 393 



the breast. Several miners started into the tun- 

 nel with him, partly impressed by my own confi- 

 dence but yet more by the hissing of the air wher- 

 ever the pipe leaked which warned them that 

 something was doing. 



"How is the ventilation, now?" I asked the 

 foreman as he came back with his eyes bulging. 



"Never saw anything like it. We'll have to 

 chain the drills to the breast to keep 'em out of 

 the pipe." 



The principle was simple enough, being that of 

 the Sprengel air pump which I had employed in 

 many ways in my laboratory and which is in use 

 for exhausting the air in the glass bulbs used for 

 electric lighting. 



Ned and I varied the monotony of our work 

 by doing a little mining ourselves. Our drilling 

 was single-handed for although I had the nerve 

 to hold the drill while my companion wielded the 

 sledge, I could never strike an efficient blow while 

 he held the drill. Then I never acquired the true 

 miner's nonchalant air as I crimped with my 

 teeth the fulminating cap on the fuse. I couldn't 



