34 rnePorT— 1890. 
through the agency of these new varieties of explosive agents, employed in 
guns of suitable construction, would appear at first sight to promisea very im- 
portant advance in the power of artillery ; the practical difficulties attending 
the utilisation of these results are, however, sufficiently formidable to place, 
at any rate at present, comparatively narrow limits upon our powers of 
availing ourselves of the advantages in ballistics which they may present. 
The strength of the gun-carriages and the character of the arrangements 
used for absorbing the force of recoil of the gun need considerable modi- 
fications, not easy of application in some instances ; greater strength and 
perfection of manufacture are imperative in the case of the hollow pro- 
jectiles or shells to be used with charges of a propelling agent, by the 
firing of which in the gun they may be submitted to comparatively 
very severe concussions; the increased friction to which portions of the 
explosive contents of the shell are exposed by the more violent setting 
back of the mass may increase the possibility of their accidental ignition 
before the shell has been projected from the gun; the increase of con- 
cussion to which the fuse in the shell is exposed may give rise to a 
similar risk consequent upon an increased liability to a failure of the 
mechanical devices employed for preventing the igniting arrangement, 
designed to come into operation only upon the impact or graze of the 
projected shells, from being set into action prematurely by the shock 
of the discharge; lastly, the circumstance, that the rate of burning 
of the time-fuse which determines the efficiency of a projected shrapnel 
shell is materially altered by an increase in the velocity of flight of the 
shell, also presents a source of difficulty. 
The fallibility of even the most simple forms of fuse, manufactured in 
very large numbers, although it may be remote, must always engender a 
feeling of insecurity, when shells are employed containing an explosive 
agent of the class which, in recent years, it has been sought, by every 
resource of ingenuity, combined with intimate knowledge of the pro- 
perties of these explosives, to apply as substitutes for gunpowder in shells, 
on account of their comparatively great destructive power. 
One of the first uses, for purposes of warfare, to which it was attempted 
to apply gun-cotton, was as a charge for shells. But even when this was 
highly compressed, and accurately fitted the shell-chamber, with the in- 
tervention only of a soft packing between the surfaces of explosive and 
of metal, to guard against friction between the two upon the shock of the 
discharge, no security was attainable against the ignition of the compara- 
tively sensitive explosive by friction established within its mass at the 
moment when the shell is first set in motion. By the premature explosion 
of a shell charged with gunpowder, no important injury is inflicted upon 
the gun, but a similar accidental ignition of a gun-cotton charge must 
almost inevitably burst the arm. The earlier attempts to apply gun- 
cotton as a bursting-charge for shells were several times attended by very 
disastrous accidents of this kind; but the fact, afterwards discovered, 
