282 CARBURETTED HYDROGEN. 



Q. What kind of thing is the SAFETY LAMP ? 



A. It is a kind of lantern covered 

 with a fine gauze wire, instead of glass 

 or horn. 



Q. How does this fine GAUZE WIRE prevent 

 an EXPLOSION in the coal mine ? 



1st Because flame will never pass 

 through fine gauze wire : and 



2ndly Though the wire get red-hot, 

 it will not ignite the gas ; for carburetted 

 hydrogen gas can be ignited only by 



flame. 



i 



(N. B. The interstices -of the gauze wire must not 

 exceed the 7th of an inch in diameter.) 



Q. Why will not FLAME PASS THROUGH very 

 fine wire- GAUZE ? 



A. Because the metal wire is a very 

 rapid conductor of heal ; and when the 

 flame of burning gas in the lamp reaches 

 the wire gauze, the heat (which is 

 needful to produce flame) is conducted 

 away by the wire, and the flame is 

 extinguished. 



Q. Does the gas of the COAL-PIT get THROUGH 

 the wire gauze INTO the LANTERN ? 



A. Yes; but the inflammable gas 



