ry field pieces, as does also the automatic
breech-closing and firing mechanism. In fact there is no pronounced
deviation from the prevailing Krupp system, and only such modifications
as are necessary to adapt the arm to its special duty. When the gun
is elevated to high angles the shell, after insertion the breech is
prevented from slipping out by means of a special device, so that the
proper and automatic closing of the breech is not impaired in any way.

In such an arm as this, which is designed essentially for high-angle
firing, the sighting and training facilities require to be carried
out upon special lines, inasmuch as the objective is necessarily at a
considerable altitude above the horizon of the gun. In other words, in
firing at a high inclination, distance between the gun and the target
cannot be utilised directly for the back sight. On the other hand, it is
essential that in proportion as the angle from the horizontal increases,
the back sight should be lowered progressively in a manner corresponding
to the distance.

To assist the range-finder in his task of sighting it is necessary that
he should be provided with firing tables set out in a convenient form,
which, in conjunction with the telemeter, serve to facilitate training
for each successive round. In this way it is possible to pick up the
range quickly and to keep the objective in the line of fire until it
either has been put hors de combat, or has succeeded in retiring beyond
the range of the gun.

The sighting arrangements of these Krupp anti-aircraft guns are carried
out upon these lines. Beneath the barrel of the back-sight is an
observing glass with an eye-piece for the artillerist, while above
and behind the observing glass is another eye-piece, to be used in
conjunction with the manipulation of the back-sight. The eye-piece
of the observation glass is so made that it can be turned through a
vertical plane in proportion as the angle of fire increases in relation
to the horizontal. The determination of the distance from the objective
and from the corresponding back-sight as well as the observation of
the altitude is carried out with the aid of the telemeter. This again
carries an observation glass fitted with an eye-piece which can
be turned in the vertical plane in the same manner as that of the
fore-sight. By means of this ingenious sighting device it is possible to
ascertain the range and angle of fire very easily and speedily.

The weight