138 
CAPTAIN NOBLE AND MB. E. A. ABEL ON FIBED OUNPOWDEB. 
ABSTBACT OF EXPERIMENTS. 
In this abstract the following abbreviations are used : — 
l to represent the mean density of the products of explosion ; A the area of the 
piston of the crusher-gauge ; a, the sectional area of the crushing-cylinder. 
Experiment 1, April 20, 1871. — The cylinder (fig. 2, Plate 14) having been prepared 
for the experiments, was calibrated and found to contain 14,000 grs. (907-2Q grms). 
A charge of 1400 grs. (90-72 grms.) It. L. G. powder was then placed in the cylinder 
and fired. 
The gaseous products of combustion were collected in tubes and sealed. 
On opening the cylinder the solid products of combustion were found adhering to 
the sides pretty uniformly, but thicker at the bottom ; they had to be scraped off for 
collection. 
_ . Crush, copper Pressure per 
cylinder. square inch. 
•0940 -1667 -0417 -009 1-6 ton. 
Experiment 2, April 4, 1871. — Fired 3500 grs. (226-80 grms.) It. L. G. powder as 
above, in a similar cylinder, the powder exactly filling the space in which it was 
confined. 
The gas was retained in the cylinder for about a second, and then, owing to a want 
of accurate fit in the collecting-screw, made its escape with a considerable explosion, 
completely, so to speak, washing away every trace both of the male and female screw 
along the channel it cut out for itself. 
On opening the cylinder but little solid residue was found, and that uniformly 
distributed over the surface, and about -07 inch thick. 
Its colour was of a very bright vermilion red, rapidly changing to black on the 
surface, and was similar in all respects to the deposit so often seen in the powder- 
chambers of heavy guns. 
Residue collected and sealed up in a test-tube. 
- . Crush, copper Pressure per 
cylinder. square inch. 
•915 -1667 -0833 -293 34-5 tons. 
Experiment 3, April 29, 1871. — Cylinder No. 6 calibrated and found to contain 
14,702 grs. (952-68 grms.). 2940 grs. R. L. G. (190-54 grms.) were fired and the gases 
collected within fifteen minutes after firing. 
On opening the cylinder the solid products were found to be collected at the bottom, 
only a very thin light-coloured deposit being on the sides. 
The appearance of the deposit was very different from any yet obtained, being grey 
on the smooth surface and very bright yellow in fracture. It was exceedingly hard 
and very deliquescent. 
The interior surface of the cylinder appeared quite bright when the deposit was 
removed. 
