OF THE FLAME IN THE EXPLOSION OF GASES. 
331 
to a steel bomb, C, in which a small charge of fnlmiiiate could be fired. The bomb 
and connecting pij^e were filled with air, while A was filled with a mixture of 
cyanogen with two volumes of oxygen. The fulminate in its copper case, f, was 
Inserted through a rubber stopper in the end of the steel tube, cl, which was screwed 
into the bomb. A and cl were connected with tubes fitted with firing wires, so that 
an explosion could be set up simultaneously in the cyanogen mixture in A and the 
electrolytic gas in cl, the connecting tap being turned on immediately l)efore the 
explosion. The lengths of the tube were so adjusted that the sound-wave started in, 
the bomb by the detonation of the fulminate should be propagated through the air 
and cyanogen mixture so as to meet the detonation-wave coming in the contrary 
direction before the latter reached the end of the tube A. The detonation-wave was 
then photographed as it met the sound-wave. 
In fig. 19 (Plate 12) the detonation-wave is seen advancing from riglit to left. The 
sound-wave strikes it jiear the centre of its path across the field of view, and the 
progress of the sound-wave is made visible as it traverses the Iieated gases from left 
to right. After meeting the sound-wave, the detonation proceeds some distance at 
full speed, and then its velocity slackens—as it meets the rush of air driven on to it 
from the detonation in the bomb. A second sound-wave, an echo of the first 
reflected from the ends of the bomb, next traverses the heated gas; and higher up 
the passage of a third sound-wave is registered on the photograph. The first sound¬ 
wave is no doubt retarded by the movement of the gas in the opposite direction, but 
the second wave appears to travel in almost stationary gas, while the third is only 
slightly retarded. The rates of these sound-waves have been measured, and the 
corresponding temperatures calculated. These values are given in Table V., on the 
assumption that the combustion was complete. 
Table V. 
Number. 
Velocity of sound-waves in 
exploded mixture C 2 N 2 + 2 O 2 . 
Calculated temperatures. 
y for diatomic gases = 1 Ml. 
y for triatomic gases = 1 • 28. 
1 st 
1116 metres per second 
“ C. 
4100 
2 nd 
1014 „ „ „ 
3330 
3rd 
893 ,, ,, ,, 
2530 
2 u 2 
