THE ROYAL ARTILLERY INSTITUTION. 
71 
tliat breathing became almost impossible, and the doctors in attendance 
declared that to remain there any longer would be attended with the highest 
danger to the gun detachment. The fifty rounds lasted eighty minutes. 
After a much greater number of rounds had been fired with gun-cotton 
there was only a thin light cloud which did not impede the aiming of the 
piece or the breathing of the men in the slightest degree. No one com¬ 
plained of any uncomfortable sensation, and the medical men were of opinion 
that the firing might have been continued much longer without any harm 
arising. Gun-cotton was likewise fired from the lower decks of men-of-war 
with similar results. 
Effects on the sides of embrasures .—It is well known that the firing of a 
gun with a large charge of powder through an embrasure causes such a 
concussion that the embrasure becomes, in the course of time, considerably 
damaged, and the fact is of sufficient importance to render desirable that the 
comparative effect of gun-cotton should not be overlooked. A trial was 
accordingly made by the Austrian committee (in 1853) in which gun-cotton 
was put under a disadvantage, by being fired from shorter guns and 
through embrasures with narrower openings. The embrasures for the 
powder guns were of a bad construction, in order that the damage might 
soon be apparent, but they were of the ordinary width. After no very 
great number of rounds (niclit ubergrossen zalil) these embrasures became 
positively unserviceable, the sides, soles, and tops being all in such a state 
that the firing could not have been continued without rebuilding them. With 
the gun-cotton, notwithstanding that the guns were shorter and the openings 
narrower, an equal number of rounds were fired without causing more than a 
very slight injury (nur die mindeste Beschadigung) and the firing might 
have been continued much longer without rendering necessary any repairs to 
the embrasures. 
Effect on the materials of the gun. —This depends very much on the 
manner in which the cartridge is made up, the strain upon the gun being 
enormously increased if the rate of explosion is not adapted to the resistance 
which the shot offers. Previous to the discovery that the rate of explosion 
might be regulated by the mechanical arrangement of the cartridge the bores 
of the guns were very much injured, and this was one of the great objections 
to the use of gun-cotton. What practical importance it may still have can 
only be determined by experiment, but it appears that gun-cotton may be 
used without leaving any trace of its action. Baron von Lenk states that 
about one thousand 12-pr. shots were fired with a charge of 17 oz. of cotton 
from a bronze gun, without affecting the bore in the slightest degree. In 
this case the cartridges were hollow; in other instances solid cartridges, 
slightly compressed, were used, and a considerable enlargement of the bore 
was caused, although the actual quantity of cotton was less. With a harder 
metal than bronze the gun-cotton has less effect on the bore, and it may 
be employed in a manner which will produce a more energetic force. 
Effect on the range and velocity of the shot. —It has been already 
mentioned that 1 lb. of gun-cotton produces about the same range as 3 lbs. 
of gunpowder, and the resultant initial velocity is about equal, but the 
reports on these points do not give that precise information on various 
