We need not here add any thing respecting the man ner in which all these fireworks may be varied by the addition of lights or stars, as it would be merely to re peat what has been said before on that subject. Neither need we do more than barely suggest, that by a proper disposition of cases, any of these may be caused to throw up stars or serpents at any period that the artist may choose.
But we may as well suggest that a good way of ter minating all these fireworks is by discharges of sky rockets, which, for this purpose, may easily be secured out of danger behind a proper board, and so as to com municate by means of leaders with the last portion of the fixed work Sky rockets may also appear to be thrown up by these at any time For that purpose, it is best to have a case of some slow fire, like a port-fire, which gives little light, arid the burning of which is accurately known. Proper holes being then made in it, at regulated distances, with a leader to each rocket, they can be discharged in succession at any interval which the operator pleases, and without the least diffi culty. It is only necessary to take ewe that, while the leaders are so well secured to the mouths of the rockets as to prevent the entrance of any accidental fire, these may at the same time be so weak as to be easily detached by the blast of the rocket, so as not to impede its ascent.
Of Complicated Fireworks.
To attempt to describe even a very small part of what may be effected by complicating different kinds of fireworks, would in itself require a volume, both of de scriptions and plates ; as, without the latter, no words could render them intelligible. We shall therefore li mit ourselves to a few, which, either from their being in common use, or from their beauty, or from their suggesting hints for the construction of others, may appear most deserving of description We must also confine ourselves to the simpler complications ; because, as these may again be combined without end, there would be no limits to such a treatise. It is an art in which no one will succeed well on a great scale who has not some invention and taste of his own ; and there fore minute and numerous directions would be nearly as superfluous to one class of readers as they would be useless to another.
The general rules for all complications of this nature are the following : An agreeable general outline, in the form of the fire, should always be studied ; as a great deal more than is supposed by vulgar artists de pends on picturesque beauty in these cases. All pyra midal or angular shapes are therefore preferable to pa rallel or square ones, which generally look heavy. Cir cles and ellipses exceed all other forms in beauty ; but the latter has been very much neglected by pyrotech nists, who are too apt to proceed according to old rou tines. No firework of this kind should therefore be con structed without previously making a drawing of it ; as also of its effects, which, for greater security, should be done in colours, so as to resemble the intended fire as nearly as possible in its colours, as well as in its form.
The next thing to be recollected is, that there should be no dullness in the execution, as the essence of all fireworks depends upon their liveliness. If any thing dull appears prudent, which it may sometimes be, for the purpose of being followed by something brilliant, and thus exciting surprise, it should be of short dura tion, that the spectators may not attribute to a failure what is the result of a design. It is a necessary rule also, that a firework of this kind should commence in a tranquil manner, that it should go on increasing in splendour and force, and that it should terminate as suddenly as possible at the height of its strength. It is always very unpleasant to see them expire gradually. Hence it is useful to be provided at the termination with reports, or stars, or explosions of serpents, that the attention may be taken off from the principal work, which. with all the care that the artist can bestow, will not always burn out alike. But all draggling of solitary cases at the end, ought as far as possible, to be avoided, and, for this purpose, the artist must attend to the direc tions formerly given about time.
Lastly, the greatest care must be taken with respect to the management and disposition of the leaders, the freedom of all parts where motion is required, and the general steadiness and accuracy of all the former works.