'The views and opinions of Brigadier General John Jacob, CB. Aide-decamp to the Queen; Aide-de-camp to the Governor General of India, &c. &c. &c.; late commanding in chief the British forces in Persia; at present commanding the Sind Irregular Horse, and Political Superintendent of the North-West frontier of Sind.' [‎262] (292/481)

262
required so far. But, on the other hand, the shape of the
Minie ball is by no means well adapted for overcoming the
resistance of the air; while its want of solidity, owing to
the hollow in its after-part, also very much lessens its
virtual specific gravity and momentum, and thus adds to
the effect of the air's resistance on its fore-part.
The shape of the ball used by me (those of two and a
half diameters in length are, I think, best) is that which 1
find by experience to be the best adapted for overcoming
the resistance of the air, and, being perfectly solid behind,
this ball is capable of sustaining the shocks of any charge
of powder whatever.
It has, however, a strong tendency to fly with the wrong
end first, exactly contrary to the behaviour of the Minie;
and to counteract this perversity, a great twist in the rille
grooves, giving a rapid spiral motion to the ball in its flight,
is necessary.
In proportion to its calibre, this ball is very much heavier
than the Minie ; to give it the same velocity, then, it is
necessary to use a larger charge: but the advantage of
the shape of its fore-part in overcoming the resistance of
the air, as compared with other projectiles, is only fully
developed at high velocities, which cannot be economi
cally used with round-ended balls like the mlnie,
on account of the excessive increase of resistance which
they sustain. With my projectiles, then, a higher velo
city than that given to the Minie is proper ; the charge,
therefore, must be still further increased for this purpose ;
wherefore the barrel of the rifle must be very strong.
Again, the ball is capable of standing the force of any
sudden shock, so that a large charge of the best powder
procurable may be used to advantage; and no great
time is required in which to impress the necessary pro-