A Manual of Pyrotechny; or, A Familiar System of Recreative Fire-works

by G. W. Mortimer

Directions for filling and ramming.

To avoid this disappointment, and to render more certain the ascent of the Rockets, the following directions must be attended to:—

1. Your composition must not be too dry, or it will be liable to disperse, and fly about in a kind of subtile meal or dust, while you are driving it; but if you moisten it a little just to destroy its dusty nature with some of the liquid mentioned in the early part of our Manual, it will cause it to collect, and be more solidly compressed in the case of the Rocket.

2. No more of the composition should be put into the case at each ramming, than will cause it to rise one half of its interior diameter; and the filling must be thus gradually continued, till the charge rises exactly one diameter above the piercer.

3. Much has been said by writers on Pyrotechny respecting the number of blows proper to be given to the rammer, to each ladle full of composition, (a piece of copper made into the form of a scoop, and holding the proper quantity answers best for a ladle;) some have assigned to Rockets of four ounces sixteen strokes with the mallet, to those of one pound twenty-eight strokes, and so increasing the number of strokes by six, to every pound; but in our opinion these rules are more ridiculous than useful; for the same mallet, by possessing a different momentum, might produce an effect, at one time double, treble, or perhaps less, than at another. It is therefore impossible to assign any determinate number of strokes, to be given at each ramming; the only certain rule is, that the composition ought to be driven till it becomes quite firm and compact, and that its density (as near as possible) be the same throughout the whole of the charge. If the rules for the number of strokes assist in any way to impart this property to the charge, we have not the least wish to depreciate them.

4. In ramming, it is best to keep the rammer constantly turning round in the case, and in using the perforated rammer, be sure to knock out the composition from the hollow every ramming, or it will be liable to be split by the piercer.

5. Invert the cartridge at the close of each ramming, in order that the loose particles of the composition which are not compressed may escape, for if suffered to remain in they would prove injurious to the article.

6. Rockets should always be rammed on a solid block, or on a post set fast into the earth; their ramming cannot be properly effected on any table whatever.

7. Rockets must be rammed with mallets somewhat proportionate to their magnitude; that is, if a Rocket of one pound can be properly rammed with a mallet weighing two pounds, a Rocket of two pounds should be rammed with a mallet of four pounds, or nearly in that proportion. Rockets above eight pounds cannot well be rammed by hand; but when wanted of such magnitude they must be rammed by means of a machine similar to that used for driving piles into the earth; Rockets of large dimensions, whose cases are made of a strong material, properly prepared, may be conveniently rammed without being placed in a cylinder, which will be an advantage, as so many moulds will not be required. But for this method of ramming we must be prepared with some brass or iron nipples, of the size proportionate to the Rocket, which should be made to screw into one part of the driving block; and for the purpose of making the case more firm upon it while ramming, a stake or upright piece must be made firm to the block, standing up the height of the case, and at a suitable distance from the nipple; the side of this stake next the case must be fluted out so that the case will fit closely into it; on the opposite side of the case must be applied a loose piece fluted in a similar manner; then with a cord tie the case and two half moulds (which these two pieces will nearly form) together, and the case will be ready for filling. The cartridges being filled to the proper height, i. e. one diameter above the piercer, if the Rocket is to be without furniture, separate with a wire of any kind, half the folds of the paper which remains above, and having turned them back on the composition, press them down with the rod and mallet in order to make them smooth and even. Then pierce three or four holes in the folded paper by means of a piercer, which must be made to penetrate to the composition of the Rocket. These holes are for the purpose of forming a communication between the body of the Rocket and the vacuity at the extremity of the carriage, as it is called, or that part which has been left empty. In small Rockets this vacuity is filled with granulated powder, (which serves to let them off when their charge is consumed;) they are then covered with paper, and either pinched quite close by means of the choaking apparatus, or crowned with a little conical cap, which will cause it to ascend to a greater height. If one hole only is made in the centre of the folded paper, it will answer the purpose of three or four, taking care that it be as straight as possible, and about one-fourth the diameter of the calibre of the case; in this hole a little of the composition of the rocket should be put that the fire may not fail to be communicated:—a Rocket finished after this manner is represented in [fig. 23]. In Rockets of larger dimensions, instead of granulated powder, the coffins, or pot containing the stars, serpents, petards, &c. are adapted to the top of the case: the petard is a small round box of tin-plate united to the diameter of the case, and filled with fine gunpowder; it is deposited on the composition after the ramming, and the remaining paper folded down over it to keep it secure; the petard produces its effect when the Rocket is in the air and the composition is consumed. The other furniture is attached to the Rocket by adjusting to its head an empty pot or cartridge of larger dimensions than itself, in order that it may contain the various appendages, which are to render it so superior to the others, in the beauty and splendour of its emication.