262 
MINUTES OF PROCEEDINGS OF 
It may therefore be taken for granted that the time of burning of one of 
these fuzes increases in the ratio of 0*0011 of its value for each diminution 
of *1 mm. (0*0394 in.) of pressure. 
These facts are very important in a military point of view, and should be 
taken into serious consideration whenever the time of burning of a fuze is 
an essential element of its employment. 
At first sight it would appear as if the increase of time of burning when 
the density of the atmosphere is less, were due to the decrease of oxygen. 
This cannot be so, as the fuze composition contains in itself a sufficiency of 
combustible gas in the form of nitrate. To make quite sure that the supply 
of oxygen from the air does not affect the question, I burnt three fuzes in a 
large bell filled with pure carbonic acid. The fuze was lighted by an electric 
current. The mean time of burning under a pressure of 715 mm. (28*15 in.) 
was 8*57 s. 
It is then the purely physical effect of the change of pressure, which acts 
in such a marked manner on the rate of burning of fuzes. 
