This is adapted for small lights. If large lights are wanted, the powder may be omitted, and the composi tion be altered as follows: Of Stars.
These are an essential ingredient in sky rockets, in Roman candles, and for explosions from mortars; and, as they produce very brilliant effects, they deserve the care and attention of the artist.
A necessary property of all stars is, that they should be hard enough to bear the explosion of the powder which is to set them on fire, and that their light should be bright and showy. Hence, although we have given some of the least exceptionable of the usual receipts for them, we do not recommend any but those from anti mony and from zinc ; the former of which burns with a blue flame, and the latter with a white one. We se !eel the following as that in most genZral use, and as sufficient for most purposes.
But besides these stars, which arc made up naked, they are sometimes made in paper cases, which must not however consist of more than two turns of paper, and which are open at both ends. The use of,this con trivance is to protect them from the violence of the ex plosion, when hired out of puts or mortars.
Stars may be strung together in chains by passing a strong piece of twine through the middle of a great nun,ber «hole they are wet, or rolling them upon the twine. By means of this contrivance, they do not at first disperse when exploded ; but as this happens almost immediately afterwards from the buroing'of the twine, the effect gained in this way is very transitory.
There is a variety mentioned in the books called tailed stars, and which ate said to show a tail of sparks' like a comet." This is one of the fictitious inventions in which all these books abound, and which seem often to have been put down by gu,_ss. We think it right to mention the names oh a tvw of these, partly that our readers may not think that we had hirgotten them, or were ignorant of them, and partly as a caution to the in experienced who, in follow ing such directions, can only lose their money and their lalour. It is impossible to cause a star to show a tail of sparks, as a case is requisite for that purpose ; and if there is to be such a train of fire, it is no longer a star but a squib.
This composition must be made into a paste, with a solution of gum arable. It may be rolled into balls about the size of a pistol or musket bullet ; or what is better, it may be forced into metal cylinders formed of two longitudinal pieces. When dry, it can be cut into convenient lengths. It must be of a stony hardness when dry, or it will not bear the force of the explosion. If there is too much gum, it is apt to miss fire. Isin glass, dissolved in spirit of wine, is recommended in the books; but it will not dissolve in that fluid.
Serpents for Sky Rockets.
Many compositions for this purpose will be found in the table, but the present one answers as well as any : it is as follows :— This is rammed into paper cases of about three lines in diameter, made with three folds of cartridge paper, the last turn being pasted. In the further end there must be some corned powder for a cracker. But the best way is to choke the case first, as for sky rockets; then to drive in the composition till it is three quarters full ; after which it is to be choked above the charge still closer, and then filled with loose powder. After that it is choked quite close, and secured at the top, the serpents arc placed in the rocket head with the mouth downwards, upon the requisite priming. The same is done if used for fixed discharges f serpents. In these there is no limit to the number that may be used at once, and as they may easily be placed in any part of a complicated firework, the effect is very lively and ornamental. When used in this manner, the paper cases must be made very strung at the sides and bot tom, and covered with a weak cover above, that they may get out easily. A little powder is placed in the bottom of the case, into which the open ends of the serpents are plunged, and there is a touch-hole bored near it, through which the quick match of the leader is introduced. The lengths should not exceed three inches for the largest diameter, or else they are apt to overset and fall to the ground. In sky rockets, how ever, their lengths may he unlimited.