The Rate of Explosions in Gases. 



155 



were detonated in an iron bomb 100 mm. in diameter. We 

 have, therefore, positive evidence that in the explosion-wave 

 the combustion cf electrolytic gas is incomplete : it seems, 

 therefore, not unreasonable to assume that in the wave- 

 front — i.e.^ at the highest temperature — a considerable pro- 

 portion of hydrogen and oxygen is uncombined, and the 

 propagation of the wave is retarded accordingly. 



§9. Mixtures of oxygen with the hydro-carbons ethylene 

 and acetylene will explode when largely diluted with 

 nitrogen. It is found both with ethylene and acetylene 

 that the rate of explosion exactly agrees with the calculated 

 velocity of the sound-wave when the mixtures are largely 

 diluted with nitrogen, but not when the gases are exploded 

 without dilution : — 



Table XXI. 



Rate of Explosion of Ethylene a?id Oxygen with excess of 

 Nitrogen compared with calculated velocities. 



