It is possible to attach two or even three rockets to one stick, so as to produce as many ascending streams of fire, and this project is recommended in the books of pyrotechny. In this case a much larger stick is of course required. But we cannot recommend this con trivance It is very difficult to make it succeed in the firing, and the cffect, when it is attained, is so little better than that of a rocket of larger size, as not to be worth the risk of failure. A similar attempt, with a slight variation, has been made to fire many rockets in one mass. These are known by the name of chained rockets. To do this, six or more rockets are fastened parallel to each other by means of packthread or other wise, each having its separate stick ; and the whole are fired by one leader. It has also been attempted to connect them loosely together, so that they may be in a certain degree independent of each other. This also is done by means of packthread. But in all these schemes we must remark that the chances of failure are so great, that they arc not worth trying, particularly as the effect, should it succeed, is not very good, Where they are strung loosely together, in the manner last mentioned, they are particularly subject to become en tangled and go wrong.
Simple rockets may be used with reports only in stead of ornaments, and their effect is good, while they serve to excite the attention of the spectators, where that is necessary, preparatory to some general display. In making this kind, after the clay has been driven on the top of the composition and the priming hole bored, a diameter and a half of the bore .must be filled with powder above it. The case must then be secured above this bouncing charge with a wadding of tow and glue, as it would destroy the explosive property of the pow der were it to be hard driven with clay, and as it is impossible to choke the case above it. A cone is then added for the usual reason of diminishing the resistance of the air.
There are two methods of carrying a single light by means of a rocket, instead of using the common or nament of stars, which are quite practicable, and have a very good effect, although not mentioned in the books of pyrotechny. For both, two diameters of the case must be left empty above the clay. This is to be filled with the same antimonial composition which is used for signal lights, or with that from zinc, both of which will be found mentioned in their proper places, accord ing as it is wished that the light should be white or blue. It must also be rammed in pretty firm, so that it may not fall out when the rocket oversets to descend. This light may be caused to descend after the rocket is burnt out, in which case the effect of it is very agreeably prolonged ; but care must be taken that it may not alight on the ground where it could do any harm, as the white light produces a very strong fire. If this
practice is to be adopted, a hole must as usual be bored through the clay on the top of the rocket charge, and also through the white light, that it may take fire at the surface : this hole is to be filled with mewled powder, but if the rocket is to early the light upwards in as cending, such a hole is unnecessary. instead of it, a leader must be conducted from the mouth of the rocket to the head, which, in this case, will not require a cone ; or else the light on the head may be fired before the rocket, which answers the purpose equally well. It is also easy to make the light of sufficient duration to last through all the time of the ascent and descent both.
Rockets may be ornamented in some other ways during their ascent, and be thus made productive of additional vat iety. Thus they may be made to dis charge serpents during their flight, either at one or more intervals, without interfering with the final dis charge from the heads. To effect this, a ring or more of small serpents, as the artist may desire, may be fastened round the rocket case by means of cotton slow-match. The loose end of that must be fired at the same time as the rocket, and its length so calculat ed as to burn three, four, or more seconds, according to the part of its ascent where it is desired that the serpents should be discharged. This cotton match must also communicate with a quick-match priming to each serpent. Thus when the fire arrives at the serpents, it not only lights the whole ring, but, by burning the match which attaches them, sets them at liberty. If two or more discharges are wanted, as many rings of serpents may be placed round the rocket, and the match duly proportioned so as to light each set in succession.
As a powerful rocket will carry conaiderably more weight than its own stick, advantage may also be taken of that, so as to add to its ornamental appearance. Thus a small case with a sparkling composition may be at tached to the end of the stick, with the mouth down wards, which must be lighted independently of the rocket; but the operator must of course take care, in adopting any of these contrivances, to ascertain previously what weight his rocket is really able to carry. Another pleasing ornament may be produced, by placing a few illumination lights or speckles, along the stick, or by attaching a larger one to its end ; but whichever of these several plans is adopted, care must be taken that the rocket has great freedom in quitting the support on which it is fired.