Manufacturers do not adhere closely to any one definite composition, although there is a marked similarity in all the compositions used. The two representative compositions are given as follows -

Per cent.

A. Barium chlorate...................

90

Powdered orange shellac ..................

10

B. Barium chlorate................

55.5

Barium nitrate..................

33.3

Powdered orange shellac....................

11.2

The substitution of barium nitrate for part of the barium chlorate is not an essential difference as both barium chlorate and barium nitrate function in very much the same manner when used in combination with powdered orange shellac since each of them gives up its oxygen which aids in the burning of the organic factor, the powdered shellac.

Ignition match tied in place.

Fig. 54. - Ignition match tied in place.

These compositions are prepared in much the same manner as has been previously described, namely, hand mixing and screening through a sieve in order to insure a homogeneous and uniform mixture. The composition marked A may be either briquetted or handled in the method described as the "older method." Composition B is used exclusively for the older method.

It is to be noted here that a certain amount of binder is necessary where the composition is briquetted, which usually consists of a mixture of one pound of gum arabic dissolved in one quart of water. Enough of this solution is taken to dampen the composition.

Parachute cord tied in place.

Fig. 55. - Parachute cord tied in place.

In reference to the assembly of this light, it is similar to the method explained previously for the assembly of the white signal light. The carton has slightly different dimensions from the carton used to hold the white light, being 1 5/8 inches in diameter and 2 1/4 inches long. One other difference also should be noted, namely, that there is no necessity for a first-fire charge such as has been discussed under the white light. In other respects the methods of assembly are the same as for the white light.

The green signal light burns from 25 to 30 seconds, giving an illumination of approximately 400 candlepower.