The British have developed also a 3-inch paper mortar for projecting signal bombs. Bombs of this variety when aloft release three colored stars that remain suspended in the air by means of a parachute. The stars are held together by 12 feet of asbestos thread. The convenience of the device is increased by the fact that the package containing it is easy to carry. A similar contrivance has been adapted to rifle grenades.

The Germans made use of a green position light, which was contained in a cylindrical zinc box, 205 millimeters in diameter and 30 millimeters in height. The illuminating charge was provided with an igniter, which was acted on by a function striker. The edges of the cover were extended over almost the entire lateral cylindrical surface of the box. The joints were protected by a band of gummed paper. A short tube, 40 millimeters in diameter and 30 millimeters in height, penetrated the cover in the center. This was soldered on the outside, and threaded to receive a zinc cap forming the plug. A function striker was set on the exterior face of this cap. A match stick was placed in the center of the tube, head upward. The head was protected by a felt washer in the bottom of the cap. The upper part of the tube contained a layer of black powder around the match, which aided in the ignition of the charge below.

The illuminating charge for one such light was as follows:

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

82.5

Tar..........................

14.5

Rough nitrate (lime salts, magnesium salts, etc.)......................

3

Another composition was as follows:

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

66.4

Potassium nitrate.....................

9.5

Powdered aluminum.......................

7.5

Resin (wood-tar pitch), with some oil and wood fiber.............

15.8

Volatile matter ........................

.8

The paste covering the head of the wooden match stick was of the following composition:

Potassium chlorate.......................

48

Clay.............................

40

Glue.............................

12

This coating was topped with a red paste having a phosphorus base.

In the operation of the light, the first effect of combustion within was to melt the zinc cover. The burning then proceeded with great rapidity, and a vivid greenish-white flame was produced, with very little accompanying smoke. The containing box itself was consumed. The whole period of combustion was nearly a minute.

The Germans employed also a lighting device of calcium phosphide contained in a metal basket. When this was released from an airship no special effect resulted if the basket fell to the ground. But if it fell into water it was instantly rendered active. Phosphoreted hydrogen was thus generated, which ignited spontaneously in the air. The combustion was easily visible to the personnel of the airship. The effect was to reveal the fact that the flight was over water.

This bomb consisted of a cylindrical tin box, having a length of 20 centimeters, and a diameter of 7 centimeters, which was divided into three compartments by means of two transverse partitions. The outside compartments were left empty, and thus served as floats. The metal covering the center compartment was cut into a latticework over a portion of its extent. This same part was provided with a hole in the center, which was closed by a lead plate, soldered on. The plate served also as ballast for the device when in the water. One end of the basket was equipped with a ring, by which it was supported before the launching. A tin band was soldered over the latticework. When the bomb was to be released, this band was removed by a pull on a ring fixed in one of its ends. The middle compartment of the basket was filled with grains of calcium phosphide having a chocolate color. The total weight of the contrivance was 470 grams, of which 250 grams were for the charge.

The construction of this device was such that, on falling into water, it immediately rose to the surface, and the effect of immersion on the calcium phosphide was the generation of phosphoreted hydrogen, which instantly burst into flame on contact with the air.

A German torch flare, in a zinc case 20 millimeters in diameter, used a mixture of barium nitrate, potassium chlorate, shellac, and aluminum powder. One of these flares burned quickly with a fairly brilliant green flame for seven and one-quarter minutes. The zinc tube of this torch, 1.5 millimeters thick, was consumed during the process of combustion, partly by melting and partly by oxidation.

Another variety of German flare was formed from a red cardboard cylinder closed at the top end with a brass cover, in which was set the percussion cap. The base of the cylinder contained two thick felt wads, on which the incendiary candle rested. A third felt wad was set in the cylinder above the top of the candle. This was perforated in order to afford communication between the candle and the cavity immediately below the percussion cap. The cavity was filled with coarse black powder, 1.9 grams. Priming paste was smeared over the lower surface of the cap. The incendiary candle itself was a red Very light, of cylindrical shape. It was marked with two lateral grooves. It was also perforated centrally. Six strands of non-nitrated cotton wick were thrust into the hollowed-out part of the candle. The ends of these strands projected upward outside the candle tip. An additional two strands of non-nitrated twine were tied lengthwise around the candle, running in the lateral grooves. These lateral grooves were thickly smeared (with priming paste, as were also both the top and base of the candle. The weight of the candle itself was 21.7 grams. Its composition was as follows:

Potassium chlorate....................

52.30

Strontium oxalate...........................

14.85

Resin (soluble in ether) .......................

18.85

Pitch and resin (insoluble in ether).....................

14.00

Still another flare was contained in a white cardboard cylinder, painted black. This contained a candle nearly three times as large as the other, having a weight of 58.35 grams. The composition was as follows:

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

40.9

Magnesium.............................

12.5

Potassium nitrate......................

37.8

Resin and wax.............................

8.8