The following recipes are from the United States Ordnance Manual, and may be considered reliable. The composition for signal lights is packed in shallow vessels of large diameter so as to expose considerable surface. Where the burning surface is large, the light attains great intensity, but the material burns out rapidly. In arranging the size and shape of the case, therefore, regard must be had to the time the light is expected to burn and the brilliancy that is wanted. [See caution at end of this article.]
Antimony, 2; sulphur, 4; mealed powder, 4; nitrate of soda, 16.
Black sulphuret of antimony, 1; sulphur, 2; pure nitre, 6. Grind to a very fine powder and mix thoroughly. See that the nitre is perfectly dry. This composition gives a bluish white light; a deeper blue may be had by the addition of a little finely pulverized zinc.
1. Saltpetre, 5; sulphur, 6; nitrate of strontia, 20; lampblack, 1.
2. Nitrate of strontia, 20; chlorate of potassa, 8; Sulphur, 6; charcoal, 1.
Saltpetre, 16; sulphur, 8; mealed powder, 4, Grind to a very fine powder and mix well.
The following have been very highly recommended:
Sulphide of antimony, 4; chlorate of potassa, 5; powdered roll brimstone, 13; dry nitrate of strontia, 10 parts.
A very little charcoal added to the above makes it burn quicker.
Fine charcoal, 3; sulphur, 13; chlorate of potassa, 8; nitrate of baryta, 77.
1. Nitrate of potassa (saltpetre), 24; sulphur 7; charcoal, 1.
2. Nitre, 6; sulphur, 2; yellow sulphuret of arsenic, 1. [Note. - This light is a very brilliant one and a very pure white, but the fumes are highly poisonous. It should be used only in the open air and the wind should blow the vapors away from the spectators - not towards them.]
3. Chlorate of potash, 10; nitre, 5; lycopodium, 3; charcoal 2.
4. Metallic magnesium in the form of ribbon or wire. This is the best and most easily used. It may be purchased of most dealers in chemicals. A few inches of magnesium ribbon coiled into a spiral (like a spiral spring) and ignited by means of a spirit lamp, or even by a little tuft of cotton soaked in alcohol and fired with a lucifer match, makes a light of surpassing brilliancy and power. It requires a slight knack to ignite the ribbon. Hold the end of it steadily in the outer edge of the flame and it will soon take fire. The Light given out by a small ribbon of magnesium is clearly visible at a distance of thirty miles.