Some realization of the development in pyrotechnic construction due to the war may be had by considering the latest French products for the 35-millimeter signal cartridge, which are enumerated in the following list:

Trail of black smoke.

Bed star.

Green star.

Two white stars.

Three white stars.

Six white stars.

Six red stars.

Red smoke.

Yellow smoke.

White caterpillar.

Red caterpillar.

Green caterpillar.

Changing-color cartridges.

Message cartridges. Before the outbreak of the war the art of pyrotechny had reached such a point that there was little difficulty to be encountered in securing adequate star mixtures for the various colors required in signaling. The use of various lights had by no means been limited to merely spectacular display. The certainty of the coloring had been tested in many practical ways and found efficient as a working agent. Thus, the railroad companies regularly employed such pyrotechnic devices, with results wholly satisfactory, after the manner to which reference has been made in a previous chapter.

So, too, the pilots of Boston and New York are familiar from actual experience with the blue light.

The military artificer, therefore, had ready to his need formulas for the making of compositions to produce whatever color he might desire. The following will serve by way of illustration:

Aluminum White Star

Aluminum ...............

2 1/2

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

14

Sulphur.....................

4

Antimony sulphide....................

3 1/2

Dextrin

1

Meal powder....................

1 1/2

Aluminum Green Star

Barium chlorate..................

8

Aluminum........................

6

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

4

Fine charcoal.......................

1 1/2

Dextrin............................

1

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

8

Red gum.............................

2

Aluminum Blue Star

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

16

Paris green..........................

8

Shellac..........................

1/2

Aluminum.............................

4

Dextrin..................................

1

Aluminum Gold Star

Aluminum..........................

2

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

3

Barium chlorate......................

2

Shellac ..........................

1

Sodium oxalate

1

Magnesium carbonate............................

1/2

Brilliant Aluminum Flash

Aluminum..............................

5

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

5

Aluminum Red Star

Strontium carbonate...........................

2

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

12

Aluminum......................

4

Shellac..........................

1

Fine charcoal.......................

1/2

Dextrin.............................

1

Aluminum Hand Lights

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

17

Aluminum.....................

5 1/2

Sulphur........................

3

Aluminum Granule

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

7

Sulphur..................

2

Antimony sulphide................

1 3/4

Aluminum.................................

1 1/2

Dextrin...........................

1/2

Marine Flare Torch

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

24

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

12

Sulphur...........................

3

Red gum .............................

3

Strontium carbonate................................

1 1/2

Pilot's Blue Light

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

11 1/2

Calomel......................

3/4

Shellac......................

12

Sulphur.....................

7

Copper oxychloride ........................

8

Railroad Fusee Signal (Red)

Strontium nitrate.....................

180

Sulphur.......................

25

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

30

Red gum..............................

10

Sawdust and grease mixture............................

10

Calcium carbonate..........................................

2 1/2

Potassium perchlorate may be largely substituted for potassium chlorate.

French White Fire

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

36

Antimony, regulus ............................

12

Red lead..........................

11

Sulphur...................................

4

White Smoke

Calomel..........................

4

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

3

Copper oxychloride.................................

2 3/4

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

2

Sugar................................

1

Sulphur.......................................

1/4

The Germans used a signal-pistol light having a star contained in a metal cylinder. The mixture used was of barium nitrate and aluminum dust, together with a small amount of binding material. In other pistol signals, a small cartridge was employed for a flash of illumination, which had its body sometimes of cardboard, sometimes of copper, with the mixture inclosed within a zinc tube. Still a third form was a small cartridge with a long fuse. This was distinguished by a more powerful firing charge. A zinc cylinder within the cartridge contained two free stars, which were surrounded with priming powder. At the base, a compact mass of black powder and aluminum powder assisted in the propulsion.

The Germans used also long cardboard cartridges that carried either two- or four-star signals, contained in zinc cylinders. One style of cartridge, fitted with a parachute, served for bearing aloft either a signal or a message. This had a shell of cardboard. The dimensions were 78 millimeters of length and 26 millimeters of diameter, the diameter of the base having an additional 4 millimeters. A smaller cardboard cylinder, 18 centimeters in length, was introduced into this shell. It contained the parachute and fuse. The parachute was of paper, somewhat similar to the Japanese, with a diameter of about 20 centimeters. A propelling charge was placed in the lower part of the cylinder, which communicated with the charge of the small cartridge by means of a match. This construction is of especial interest since it points the way for a pistol light carrying the desired number of stars, which can be fired from ordinary 10- or 12-gauge cardboard shotgun shells, readily available in any desired quantity.

The Eizfelds signal cartridge, employed by the Germans, was made up of a metallic case loaded with powder, and carrying a cylindrical block of illuminating mixture, of which the composition was:

Barium chlorate.............................

84

Gumlac................................

16

It should be remarked that in this instance barium chlorate serves in place of the nitrate. Thus, the Germans effected a necessary economy. This substitution was made possible by perfecting the electrolytic manufacture of barium chlorate through development from the chloride.