muzzle-loading as regards ballistic effect. With a shot loaded from the
front, it is clear that it must be smaller all over than the bore, or it
would not pass down to its seat. A shot thrust in from behind, on the
contrary, may be furnished with a band or sheath of comparatively soft
metal larger than the bore; the gas then acting on the base of the
projectile, forces the band through the grooves, sealing the escape,
entering the projectile, and, to a great extent, mitigating the erosion
of surface. This is, of course, universally known. It is also pretty
generally known among artillerists that the effect of the resistance
offered by the band or sheathing on the powder is to cause more complete
combustion of the charge before the shot moves, and therefore to raise
the velocity and the pressure. But I believe it escaped notice, till
observed in May, 1880, in the Royal Gun Factory, that this circumstance
affords a most steady and convenient mode of regulating the consumption
of the charge, so as to obtain the best results with the powder
employed.

Supposing the projectile to start, as in a muzzle loader, without
offering any resistance beyond that due to inertia, it is necessary to
employ a powder which shall burn quickly enough to give off most of
its gas before the shot has proceeded far down the bore; otherwise the
velocity at the muzzle will be low. To control this comparatively quick
burning powder, a large air space is given to the cartridge, which,
therefore, is placed in a chamber considerably too big for it.
Supposing, on the other hand, the projectile to be furnished with a
stout band, giving a high resistance to initial motion, a much slower
powder can be used, since the combustion proceeds as if in a closed
vessel, until sufficient pressure is developed to overcome the
resistance of the band. This enables us to put a larger quantity of
slower burning powder into the chamber, and in fact to use, instead of a