58 
CAPTAIN NOBLE AND ME. F. A. ABEL ON FIRED GUNPOWDER, 
M. von Karolyi’s method of obtaining the products of combustion consisted in 
suspending in a spherical shell a small case containing a charge of the powder to be 
experimented with. Before firing the charge, the air contained in the shell was 
exhausted ; the powder was fired by electricity. 
The arrangement will readily be understood from the sketch shown in fig. 3, Plate 15. 
After combustion, the gases were obtained for examination by means of the stop- 
cock, while the solid residue remaining in the shell was removed with water and filtered. 
The composition of the powders used is given in Table II., and the results of analysis 
in Table III. Yon Karolyi computed that the gases resulting from 1 gramme of small- 
arm powder generated 226-6 cubic centims., and from 1 gramme of ordnance-powder 
200*9 cub. centims. 
The Astronomer Royal, Sir G. B. Aiey, in a paper* published in 1863, “On the 
Numerical Expression of the Destructive Energy in the Explosions of Steam-boilers, 
and on its comparison with the Destructive Energy of Gunpowder,” considers that “ the 
destructive energy of 1 cubic foot of water (62-23 lb. =28*23 kilos.) at the temperature 
which produces the pressure of 60 lb. to the square inch is equal to that of 1 pound of 
gunpowder, and that the destructive energy of 1 cubic foot of water at the temperature 
which produces the pressure of 60 lb. to the square inch, surrounded by hot iron, is 
precisely equal to the destructive energy of 2 lb. of gunpowder as fired in a cannon.” 
Aiey takes the energy of a kilogramme of powder as fired from a gun at 56,656 
kilogrammetres= 82-894 foot-tons per lb. of powder; so that the total energy of 
gunpowder would be somewhat less than double the above value. He states, however, 
that this estimate does not pretend to be very accurate. 
In 1869 were published, in the ‘Zeitschrift fiir Chemie’f, the results of some 
experiments made by Colonel Fedoeow to determine whether the products varied 
materially with the mode of combustion. 
Fedoeow experimented (1) by firing a pistol with a blank charge into a glass tube 
4 feet long, (2) and by firing a shotted 9-pounder bronze gun with 3 lb. of powder ; the 
residues were in each case dissolved in water and analyzed. 
The composition of the powder employed by Fedoeow is given in Table II., and his 
analytical results are shown in Table III. 
From the experiments with the gun, Fedoeow calculated that the gaseous products 
were 82-6 cub. centims. N, 162-1 cub. centims. C0 2 , and 14 cub. centims. S0 2 and O. 
He considers that several successive reactions take place during combustion, that 
potassium sulphate and carbonic anhydride are first formed, while the excess of carbon 
reduces the sulphate to carbonate, hyposulphite, and carbonic anhydride. 
In 1871 Captain Noble $, one of the present writers, in detailing to the Royal 
Institution his earlier researches on the tension of fired gunpowder, stated that the 
conclusion at which he had arrived from the results of his experiments, where the 
* Philosophical Magazine, ser. 4, vol. xxvi. p. 329. , f Yol. v. p. 12. 
t Proceedings of Royal Institution, yol. vi. p. 282.. Revue Scientifique, No. 48, p. 1125. 
