ON THE APPLICATION OF GUN-COTTON TO WARLIKE PURPOSES. 31 
that with harder and more resisting metal than bronze, the great power of 
gun-cotton might unhesitatingly be made use of to obtain a more energetic 
projectile force than would have been compatible with the use of gunpowder, 
The results are as follows:— 
A Krupp 6-pounder, cast steel, charged ‘with | 1338 feet per second initial 
30 oz. of normal powder ...,....---++:,-+> velocity of shot. 
A Krupp 6-pounder, cast steel, charged with | 1563 feet per second initial 
134 02. of gun-cotton ........-.+eeeeees } velocity of shot. 
In practice it is necessary with the use of gun-cotton to reduce the 
“ windage” to a minimum ; otherwise larger charges must be used, and with 
no corresponding advantage. 
c. Application of gun-cotton to rifled ordnance.—The time may have ar- 
rived for breech-loaders, which have lately come into use under such good 
auspices, to be set aside in favour of muzzle-loaders, for the service of which 
gun-cotton offers such facilities, because of its leaving no solid residue after 
combustion, and because windage admits of reduction to a minimum, 
The method of determining the condition of charge differs from the data 
given for smooth bores, in so far that the vehemence of explosion may be 
decreased by mechanical means—such as variation of length of chamber, 
regulating the mode of ignition so as to attain a sufficiently favourable con- 
dition of starting of the projectile from rest. This result was easily achieved 
(as demonstrated by experiments conducted in Austria) within the degrees 
of velocity hitherto deemed sufficient, as by the gun shown, Pl. I. fig. 1, 
and cartridges, Pl. II. fig. 1. 
To what extent these deductions may hold good ai higher velocities, must 
be determined by further experiments, which may be expected, judging from 
present data, to give fayourable results. 
The Austrian breech-loading guns (cast iron) of three service calibres 
(6, 12, and 24-pounders charged with 13, 30, and 60 lbs. weight projectiles 
respectively) answer perfectly when charged with gun-cotton, provided the 
chambers are enlarged to 1-1 of the original capacity for powder. For larger 
charges, cartridges made in the form of a hollow rope, similar to those used for 
blasting, would answer; however, I have to remark that it is more necessary 
in rifled than in smooth-bore guns to reduce the windage to a minimum; 
this, on account of the surprising exactness of work in English factories, would 
_ be easy of accomplishment, and would raise the effect of gun-cotton. Expe- 
riments performed with a cast-steel gun of 3 inches diameter, weighing only 
50 Ibs., firing hollow projectiles with effect to 3000 yards, demonstrate that, on 
account of the short length of tube necessary and the slight recoil, very light 
pieces can be made, Pl. I. fig. 3; the carriage was about 40 lbs. weight. 
d. Application of gun-cotton to small arms.—In this respect it is important 
to observe that the plasters used with the old round-ball rifles were com- 
pletely torn so long as short cartridges were used. When I elongated the 
cartridges the plasters resisted perfectly, and practice was very accurate ; 
hence it is demonstrated that length is a very important element in the con- 
struction of small-arm cartridges. Experiment only can determine the ro- 
per length. 
One circumstance is not to be lost sight of—that w'th a very long cartridge 
the ignition of it in proper time may be difficult to achieve. Fractice in the 
application of mechanical means is requisite to secure the proper explosion 
of long cartridges by igniting them well in front. Lastly, experience proves 
that in small-arm cartridges separation of the cotton into several layers, by the 
