fine, suspending wire, which is sheared by the inertia of the pellet on
discharge, a needle lighting a percussion patch of composition and the
composition ring, B B, which burns round at a given rate until it reaches
the communication passage, C, when it flashes through the percussion
pellet, E, and ignites the magazine, D, and so ignites the primer shown in
Fig. 6, flashes down the central tube of the shell, and explodes the
bursting charge in the base, Fig. 5. The length of time during which the
fuse burns depends on how far the composition ring is turned round, and
what length it consequently has to burn before it reaches the communication
passage, C. If the fuse should be set too long, or from any other cause
the shell strikes before the fuse fires the charge, the percussion action
fires the shell on graze by the following arrangement: The heavy metal
piece containing the magazine, D, constitutes a striker, which is held in
place by a plain ball, G, near the axis of the fuse and by a safety pellet,
H. On first movement in the gun, this latter by inertia shears a suspending
wire and leaves the ball free to escape above it, which it does by
centrifugal force, leaving the magazine striker, D, free to fire itself by
momentum on the needle shown above it, on impact. There is a second safety
arrangement, not shown in the figure, consisting of a cross pin, held by a
weak spiral spring, which is compressed by centrifugal force during flight,
leaving the magazine pellet free to act, as above described, on impact.

The armor-piercing projectile is shown in Fig. 7. It is to be made of
forged steel, and supplied by Elswick. In appearance it very closely
resembles those fired from the 100 ton gun at Spezia, but if it is made on
the Firmini system, it will differ from it in the composition of its metal,
inasmuch as it will contain a large proportion of chromium, probably from 1
to 2 per cent., whereas an analysis of Krupp's shell gives none. In fact,
as Krupp's agent at Spezia predicted, the analysis is less instructive than
we could wish.--_The Engineer_.