If stars are to be projected, either alone, or with ser pents and crackers, a sufficient charge of grain powder for the intended or, osc is also required; and it is to be managed in the same manner. To prevent dis turbance in the carriage, the pasteboard division or wadding may be pasted at the margin slightly to the case, by means of a hit of thin paper ; but it is a gene ral rule to avoid oversetting these fireworks in the carriage, as the mealed powder might get into the chokes of the serpents, and cause them to burst in the cases. For stars, this is of no consequence. It may indeed be preferable generally to keep these cases filled, all excepting the 'mated powder, which may be intro duced just before the time of firing. In this way, the paper which is to cover and secure the serpents, must be pasted in a cylindrical manner round the case, so as to be twisted up at the top loosely. Otherwise it may be fastened down like the head of a drum ; hut in every way it must be made slender, so that it may easily blow up Such cases as we have now described, if used alone, may be fired by a leader of quick match inserted into the top, and furnished at the extremity with a hit of slow match, so as to allow the operator time to retire. But it is usual in public displays to fire many at once; in which case all the leaders must communicate with a common one, which may also be conveniently attached to some case of ordinary fire that may burn first, and thus give time.
It is further easy to sec how these may be united to Roman candles, or gerbes, or white lights, or any other class of fires. But for this purpose they' must all be fixed together in frames; and the leaders, which are to communicate to the pots of serpents, should enter by a hole at the bottom. A conical, hard, but loose cup should also be placed over the mouths, to prevent chance of a spark falling into them and inflaming them before their time. All these pots may be used in the water by means of proper floats, and the serpents when thrown on the water, have a good effect if they are made light enough to swim.
Of Balloons.
These are contrivances for carrying squibs, or ser pents, or stars, or crackers, high up into the air before bursting. Being thus dispersed from a single point, they produce a strong effect. Directions have already been given for making the cases, and those for the fuses will be found under the head of military fire works. A sufficient quantity of powder must be in troduced to burst the shell and inflame the contents, and the morter used to fire them must be regulated in the same way to throw them as high as may be de sired.
Balloons may also be used upon the water; hut with out any particular advantage. It is recommended in the books of pyrotechny to sink them under the water and inflame them by means of a projecting case. But so far from any thing being gained in this way, the con tents will be half lost by sinking in the water. This is one of the schemes so common in the books on this art, which seem to have. been entered among others without any consideration.
Single Crackers and Maroons.
These are an essential part of all fireworks, and may be attached in various ways to other kinds of cases, as we have already suggested. The one or two ounce case, is sufficiently large for ordinary purposes ; hut crackers may be made of any dimensions which the operator may think fit. The length may vary from
two inches to four, and the cases must be unusually strong, as the effect depends entirely on that circum stance. They must be filled with grain powder, pressed in, but not bruised. When full, the cases are to be choked at the upper end in the engine as closely as possible ; introducing a bit of wood at the same time to preserve a touch hole. They are then primed with a bit of quick match, fastened in by a bit of pasted paper, when they are ready to be attached wherever they may be wanted.
This is the practice for crackers that are to be fasten ed to other fireworks. But if they arc required to be thrown out of pots or mortars, about a diameter of the case above the vent must be left unfilled when it is choked. Into this a slow charcoal composition is to be introduced, and rammed firmly down, that it may burn for a second after the cracker has been thrown out, so as to allow it time to explode in the air ; and no priming is required in this case, as it is lighted by the blast of We explosion.
When crackers are required for separate firing and merely for the sake of the reports, they are made nett stronger, and are then called maroons. The case being filled in the same manner as before, the ends of the folds of paper at the open part are turned down upon the charge in succession, and pressed firmly on it with the aid of a little glue, so that it is entirely closed. It is then covered with numerous turns of waxed twine and paper in succession, till it becomes a ball as strong and thick as the operator chooses. Theloudness of the report depends on this circumstance. As maroons are generally used for the purpose of firing salutes, they must be connected together to the requisite num ber, and in such a way that they may fire in succession without the risk of disabling each other. To do this conveniently, a priming hole must be bored in each with a small gimblet, and a piece of quick match in serted and properly secured in a paper tube, tied on with a string and pasted paper to the maroon. A single leader is then made, so as to burn for any length of time that the operator pleases, that a sufficient in terval may be allowed for the explosion of each cracker. This must first be well secured to a wooden frame by Rails or twine; and holes being then made in it at pro per distances, the leader of each maroon is fixed to one of these by a sufficiently strong joint of pasted paper. The most convenient way is to allow each maroon to hang louse by means of its own tail or leader from the main conductor. Thus, when this is fired, each ma roon is detached in succession as it explodes, so as not to burn or disturb the rest ; and thus the whole may be caused to make their reports at very regular inter vals, provided the main leaders be well made. The snatch for this leader must be intermediate in quickness, between slow and quick match, and is easily made by a mixture of three parts of saltpetre to one of charcoal ; or else the leader may be filled in the manner of a case, with a charcoal composition of moderate force, which may be rammed down sufficiently hard without a mould, by means of an iron wire. The leader case must not be too strong if it is of any considerable length, that it may burst occasionally without much effort, at each joint or thereabouts, so as to give vent to the fire without any disturbance.