460 
SIR ANDREW NOBLE: RESEARCHES ON EXPLOSIVES. 
Norwegian 167, for example, gradually approaches the cordite pressure, and at the 
density of 0‘45 apparently equals it. 
The point now to be considered is : Are these slight increments of pressure in the 
Norwegian ballistites, and the much more abnormal increments in Explosives II. 
and VI. at densities of 0'5, real, or are they due either to partial detonation or to 
wave action on the crusher gauge during explosion ? 
Supposing there to be no detonation or violent motion of the gases, the pressure on 
the walls of the explosive cylinder should be dependent, in a vessel impervious to 
heat, solely on the quantity of gas produced and on the amount of heat generated by 
the explosion. 
I have, therefore, calculated for the whole of the explosives the value of the 
products (volume of gas multiplied by units of heat water gaseous) and the results are 
shown in Plate 15. 
It will be observed that the curves, which are very nearly straight lines, practically 
confirm the pressure curves of Explosives I., II., V. and VI., and they equally show 
that the abnormal pressures of II. and VI. at densities of 0'5 are not confirmed. 
To test this latter point further, I repeated the experiments with M.D. and Pt.R. 
at the density of 0‘5, so arranging the lighting of the charge that the rush of the 
nascent gases should not impinge directly on the crusher gauge. At the same time, 
to be certain that the transformation was the same, the usual course of analysing the 
products of explosion was followed. I give the results of R.R. as an illustration. It 
will be seen that the pressure indicated by the gauge was in this experiment normal, 
and, the transformation being the same, it follows that the high pressure obtained in 
the first experiment was due to wave action. 
Experiment 1513. 
Experiment 1607. 
Density. 
. 0-5 
Density. 
. 0-5 
Tons per sq. inch. 
Tons per sq. inch. 
Pressure . 
. 56-00 
Pressure . 
. 46-48 
Atmospheres . . . . 
8535 
Atmospheres . . . . 
7084 
Permanent gases. 
Percentage. 
Permanent gases. 
Percentage. 
C0 3 . 
38-75 
C0 2 . 
38-10 
CO . 
24-75 
CO . 
25-00 
H. 
10-20 
H . 
10-70 
CH 4 . 
12-00 
CH 4 . 
11-85 
N . 
14-30 
N . 
14-35 
The repetition of the same density, 0‘5, with M.D. was not so successful, the 
pressure not being considerably reduced. 
I may point out also that the curves appear to show that the pressures determined 
at the very low densities are too small, although it is true this might have been 
