parachute of strong material folded in the rear of the casing
and the cardboard tube containing the illuminating mixture is attached
to it. The time of burning varies, but is ordinarily less than a minute.
Certain structural details must be such as to endure the stresses of a
high muzzle velocity. Furthermore, a velocity of perhaps 1000 feet per
second still obtains when the star-shell with its parachute is ejected
at the desired point in the air.

The non-parachute illuminating shell is designed to give an intense
light for a brief interval and is especially applicable to defense
against air raids. Such a light aims to reveal the aircraft in order
that the gunners may fire at it effectively. These shells are fitted
with time-fuses which fire the charge of black powder at the desired
interval after the discharge of the shell from the gun. The contents of
the shell are thereby ejected and ignited. The container for the
illuminating material is so designed that there is rapid combustion and
consequently a brilliant light for about ten seconds. The enemy airman
in this short time is unable to obtain any valuable knowledge pertaining
to the earth below and furthermore he is likely to be temporarily
blinded by the brilliant light if it is near him.

The rifle-light which resembles an ordinary rocket, is fired from a
rifle and is designed for short-range use. It consists of a steel
cylindrical shell a few inches long fastened to a steel rod. A parachute
is attached to the cardboard container in which the illuminating mixture
is packed and the whole is stowed away in the steel shell. Shore
delay-fuses are used for starting the usual cycle of events after the
rifle-light has been fired from the gun. The steel rod is injected into
the barrel of a rifle and a blank cartridge is used for ejecting this
rocket-like apparatus. Owing to inertia the firing-pin in the shell
operates and the short delay-fuse is thus fired automatically an instant
after the trigger of the rifle is pulled.

Illuminating "bombs" of the same general principles are used by airmen
in search of a landing for himself or for a destructive bomb; in
signaling to a gunner, and in many other ways. They are simple in
construction because they need not withstand the stresses of being fired
from a gun; they are merely dropped from the aircraft. The mechanism of
ignition and the cycle of events which follow are similar to those of
other illuminating shells.

The val