Illuminating Fires And Bengal Fires

These fires serve to illuminate objects of a small or larger compass; hence, intensity of light is principally to be aimed at, besides, there is a condition that there be but little smoke, and that the mixture burn off slowly and regularly. The mode of using the mixtures is either to place them open on a flat dish, or to put them into stiff paper capsules prepared in the manner of rockets, but of very thin paper. These two modes require different mixtures, and produce different effects. The former gives off a larger light, but, even in large quantities of short duration, while the latter, though smaller, burns longer and with more regularity.

Open Fires

Among the many recipes for these, bat few deserve to be recommended, and these have been selected. The white and red fires only show a clear distinct color. The green is generally pale, and shows off easily when burnt after a red. A pure blue is very difficult to obtain.

The following should be observed as general rules: The ingredients for the fires are dried singly at a slightly elevated temperature, finely powdered, and preserved in well-stopped bottles until required for use. The mixing of the ingredients is best performed on a sheet of paper by means of a card, and should be done very carefully, so as to insure a complete mixture. Siding is in most cases admissible, while triturating in a mortar is, above all, to be avoided.

After mixing, the powder is piled in small heaps in open vessels, for which purpose small flower-pot dishes are well adapted. On top of these several piles some gunpowder is placed to facilitate the lighting. The vessels should be arranged in such a manner that the flame may illuminate the intended object without being seen by the spectators. The distribution of the material into a greater or less number of dishes is governed by circumstances. A great number of small flames from a given quantity of mixture generally gives a more intense, but so much shorter lived light than the same quantity distributed in larger portions. Beyond a certain limit, however, even that intensity is not materially heightened by a few more lights. If the fire is to continue for some time, it must further be considered that large quantities of the mixture form a correspondingly greater amount of slags which greatly mar the effect. It is, therefore, best in such cases to burn off a number of small charges successively.

White Fire

The following mixture is the best for white lights, being unsurpassed in brilliancy and power by any other.

I

Take-Saltpetre . 18 ounces.

Sulphur..... 10 "

Black sulphuret of antimony • 3 "

Burnt lime . • • 4 "

The sulphur is used in the form of flowers previously dried; the lime is not to be slalked, but must be' finely powdered; it must be fresh and be powdered immediately before use.

All other mixtures for white fires have either a blush tinge, or contain deleterious ingredients, which latter render them at least unsuitable for in-door use. Of this latter class we will mention only one.

II

Take-Saltpetre • • .12 ounces. Sulphu 4 " Sulphuret of tin . . 1 ounce.

Two other mixtures deserve mention, while not equal to No. 1.

III

Take-Saltpetre • . . 24 ounces. Sulphur . . . 6 1/2 " Sulphuret of sodium . 3 1/2 "

IV

Take-Saltpetre • • 32 ounces. Sulphur . . . 10 1/2 " Gunpowder . 7 1/2 "

Blue Fires

The only mixture to be relied on, though the light is not purely blue but bluish-white, is the following: -

Saltpetre.....3 ounces.

Sulphur.....1 ounce.

Black sulphuret of antimony ...... 1/4 "

Red Fires

The following mixture is the best in use; its composition may be altered by various ad-mixtures.

I

Take-Nitrate of strontia . 13 ounces. Sulphur . 1 ounce. Powder dust . . 1 "

The latter ingredient is prepared from gunpowder, rubbed up carefully in a mortar, and then sifted through a hair sieve.

II

Take-Nitrate of strontia • 12 ounces. Chlorate of potash . 8 " Stearin 2 " Powdered charcoal • 1/2 ounce.

In using chlorate of potash, the precautions we have indicated in other chapters must be strictly observed, and all pounding and rubbing avoided.

III

Take -Nitrate of strontia . . 10 ounces. Chlorate of potash 2 " Sulphur .... 2 1/2 " Black sulphuret of antimony . 1 ounce. Powdered charcoal 1/2 "

This gives a very strong light.

The nitrate of strontia for these fires, as the ingredients for all others, must be well but carefully dried.

Yellow Fire

This color, which is very little used, is produced by the following mixture: -

Nitrate of soda . . . . 3 lbs.

Sulphur . . . . . 1 lb.

Black sulphuret of antimony . 1/4 "

Powdered charcoal . . . 1 ounce.

Green Fires

The coloring ingredients for these lights are the salts of baryta; the color is generally not very deep.

I

Take-Nitrate of baryta . 22 1/2 ounces. Sulphur ... 5 " Chlorate of potash . .10 "

Calomel 1 ounce.

Lampblack • • 1/2 "

II

Nitrate of baryta • • 80 ounces.

Chlorate of potash • 9 "

Sulphur . . . . 11 "

III

Chlorate of baryta • 8 ounces.

Sulphur • • . 1 ounce.

IV

Chlorate of baryta . 1 1/2 pound.

Stearin • • 3 ounces.

Sugar of milk • 1 ounce.

V

Chlorate of baryta • 8 ounces.

Sugar of milk • • 1 ounce.