Part 5

This is effected by covering them with paste made of flower of sulphur, mixed up with thin starch, and afterwards rolling them in pulverized gunpowder, which will serve as a match or communication; when made after this manner they are called luminous marroons.

7. SAUCISSONS.--These differ only in form from the foregoing articles; till lately no distinction was made between them, nor (in our opinion) ought any to exist, but the French Artists have thought proper to give them the above name from the supposed resemblance they bear to a sausage.

The cases of Marroons are made cubical, those for the present articles are made cylindrical, and in proportion must be about four times their exterior diameter in length; their diameters may be from one to two and a half or three inches, and their cases increasing in strength as their dimensions.

The cases must be choaked or pinched at one end after the manner of rockets, and tied quite close; and afterwards the former, on which they are rolled, should be pressed hard upon the bottom to make it smooth, and to take out the wrinkles left by the choaking; the former, or interior diameter, should not exceed one half of the exterior diameter of the case.

The cases being thus prepared, they are to be filled with coarse powder one diameter, and one fourth high, and the rest of the paper must be folded down tight upon the powder; then bind them tight in every direction with strong packthread dipped in glue, and they are then left to dry as before.

They may be rendered luminous, and the match applied in the same manner as to Marroons.

_Batteries of Marroons_, &c.--These, it has been said, if well managed, will keep time to a march, or a slow piece of music. They must indeed be well managed to do so; I have (with care) made several trials, but in neither was I fortunate enough to produce that uniformity in their intervals, as to mark correctly their commencement of each bar of the music; which, if they do not, they fail entirely as to this property. But, however, much effect may be produced by these noisy pieces by arranging them on several stands, with a number of cross rails, on which they are to be nailed, and connected together by means of leaders &c. of different lengths, according to their distance asunder, observing to use the large and small marroons and saucissons in order to produce a greater variety in the reports, which during the exhibition of other articles is their chief purpose.

A Battery with the leaders complete is represented in Fig. 19.

8. GERBES.--This is a species of Fire-work which, from a cylindrical case, throws up a luminous and sparkling jet of fire, which From its partial resemblance of a water-spout, the French have given it the appellation of Gerbe.

Gerbes consist of a strong cylindrical case made of thick paper or paste-board, and filled with brilliant composition, and sometimes with stars or balls placed at small distances, so that the composition and balls are introduced alternately; immediately below each ball is placed a little grained powder. This last kind of Gerbes are more properly called Roman Candles, which we shall describe in the next article. Gerbes are sometimes made wholly cylindrical, and sometimes with a long narrow neck; the reasons for making them with a neck are deduced from rather philosophical considerations: when fired they exert great force on all parts of the case, especially at the mouth, from which it proceeds with great velocity; the reasons therefore deduced for making them with a long neck are--first, that the particles of iron, which enter into their composition, will have more time to be heated, by meeting with greater resistance in getting out than with a short neck, which would be burnt too wide before the charge be consumed, and spoil the effect; secondly, that with long necks the stars will be thrown to a greater height, and will not fall before they are spent or spread too much; but when made to perfection, will rise and spread in such a manner as to represent pretty exactly the form of a wheat-sheaf.

The diameter of Gerbes is generally estimated by the weight of a leaden ball, which the case is capable of receiving; thus we say Gerbes of eight ounces, of one pound, &c. Their length from the bottom to the top of the neck should be about six diameters; the neck being about one-sixth diameter, and three-fourths diameter long. They are filled in two ways, according as they have a neck, or are wholly cylindrical; the cases of the latter kind are closed below, and are filled like those of serpents, but the composition must be put in by small quantities, and rammed very hard; cases with necks are filled from the bottom, but you must be careful, before you commence ramming, to plug up the aperture of the neck with a piece of wood fitted to its diameter, for if this is not done, the composition will fall into the neck, and leave a vacancy in the case, which will cause it to burst as soon as the fire arrives at that part of it.

You must observe, too, that the first ramming or two be of some weaker composition than the body of the case. When filled the plug must be removed, and the neck filled with some slow charge, and capped with touch-paper; a foot of wood is afterwards to be fixed to the Gerbe and well secured, either by a cylinder fixed to the outside of the case, or by having in it a hole, into which the case may be inserted; when either of these methods is employed the foot must be firmly attached.

Sometimes sparks (Article 5,) are introduced during the filling of the cases, but in this case special care must be taken that they are not broken by hard ramming; their number should be regulated by the size of the case, and when carefully used, they produce a pleasing effect, but they are most adapted to such Gerbes as are wholly cylindrical.

The following method of finding the interior diameter of Gerbes is generally employed:--supposing the exterior diameter of the case at bottom (which is usually made somewhat larger than the top) to be four inches, then by taking two-fourths for the sides of the case, there will remain two inches for the bore, which will be a tolerable good size, and from the rules given for the height the same will be about twenty-four inches to the top of the neck. Fig. 20 represents a wooden former; and fig. 21 a Gerbe with its foot complete. The composition for filling will be found in the Table, Section 7.

In ramming large Gerbes an external mould will not be requisite, the cases being sufficiently strong to support themselves.

SMALL GERBES.--These are frequently called “White Fountains;” they differ but little, when used as Gerbes, from the foregoing: they are made of four, eight, or twelve ounce cases, of any length, pasted and made very strong: before they are filled, drive in about one diameter of their orifice high some good stiff clay, and when the case is filled, bore through the centre of the clay to the composition a vent-hole of common proportion, which must be primed and capped as before.

These cases are sometimes filled with Chinese fire, in this case the clay must not be used, but filled the same as cylindrical cases, and footed and primed in the same manner.

9. ROMAN CANDLES.--Roman Candles are constructed nearly after the manner of Gerbes; their cases are made perfectly cylindrical, as above described, and between the layers of composition, are interposed balls, or stars, which are prepared as directed in Article 4. In filling and ramming Roman Candles, especial care must be taken that the stars are not broken in the operation. When the cases have been properly rolled and dried, and their bottoms firmly secured by tying them with some strong twine, it is best, previous to putting in the composition, to ram a little dry clay, which will fill up the hollow, and leave a better bottom to the case. This being properly done, put in a small quantity of corn powder, and over this a small piece of paper, just to prevent the composition from mixing with the powder; then as much of the composition is to be put in as will, when rammed hard down, fill the case about one sixth of its height; then over this a small piece of paper (covering about two thirds of the diameter) as before, then a little corn powder, and upon that a ball is to be placed, observing to let the ball be somewhat less than the diameter of the case. Over this first ball more of the composition is to be introduced, and pressed lightly down, till the case is about one third full, when it may be rammed, but with some gentle strokes, lest the ball is broken by it; then a piece of paper, a little corn powder, and upon it another ball, as before; so that the case after this manner will contain five or six balls with regular beds of composition between them, and have about the same length of composition above the highest ball. When the case is thus filled it is to be capped with touch-paper by pasting it round the orifice, and a little priming of mealed powder being added, the piece is rendered complete.

In regard to the stars or balls, it is best that their form be flat and circular, or even square rather than spherical, as they will be less liable to be injured in the filling; they should also be somewhat different in size, which is found to add much to their effect; that is, let the first star be about two thirds the diameter of the case, let the next be a little larger, and so on increasing to the fourth, fifth, or sixth, which last should fit tight into the case.

Observe also to let the quantity of powder at the bottom of each ball increase as the balls increase in diameter, or as they come nearer the top of the case; not on account of the additional weight of the ball, but, as on those balls situate near the top, the force of the powder ceases to act on the ball, sooner than on those situate lower in the case, consequently the force to throw the ball to the same distance must increase proportionally; another reason for decreasing the quantity of powder towards the bottom is, that the same quantity used with the bottom as with the top ball, would cause the case to burst, and destroy all the effect which they are intended to produce.

The composition for filling will be found in the Table, Section 7.

The best way of exhibiting these Roman Candles is to place them in rows on a stand, some fixed quite perpendicular, others declining at different angles, that the balls may be projected to various distances, and produce a more beautiful effect. The greatest angle of declination should not exceed forty-five or fifty degrees.

A very pleasing variety of Gerbes may be produced by filling the cylindrical cases with the compositions called Chinese fire, (see next article,) being filled with red or white, and used with different proportions of the ingredients, they may be cast into many and various shades of colours.

10. CHINESE FIRE.--The principal ingredient which forms this beautiful composition, has been already described in article 6, section 2, under the name of Iron-sand; what we have to give in this place is, the proportion in which it is used with the other ingredients; the composition is rendered into two particular distinctions, namely, red and white, and each of them made with different proportions of the ingredients according to the calibres of the cases intended to be filled with it, which calibre is estimated by the weight of lead balls, which will just fill out their diameter, as was taught in the Article Gerbes.

_For Red Chinese Fire._

Calibres. Salt- Sulphur. Charcoal. Sand 1st petre. order. I. 12 to 16 lb. 1 lb. 3 ozs. 4 ozs. 7 ozs. II. 16 to 22 lb. 1 lb. 3 ozs. 5 ozs. 7 ozs. 8 drs. III. 22 to 36 lb. 1 lb. 4 ozs. 6 ozs. 8 ozs.

_For White Chinese Fire._

Calibres. Salt- Bruised Charcoal. Sand 3d petre. powder. order. I. 12 to 16 lb. 1 lb. 12 ozs. 7 ozs. 8 drs. 11 ozs. II. 16 to 22 lb. 1 lb. 11 ozs. 8 ozs. 11 ozs. 8 drs. III. 22 to 36 lb. 1 lb. 11 ozs. 8 ozs. 8 drs. 12 ozs.

After carefully weighing the several ingredients, observe to sift the salt-petre and charcoal two or three times through a hair sieve in order that they may be well mixed; the iron-sand is then to be moistened a little with brandy or spirits of wine, which will make the sulphur adhere, and they must be well incorporated. The sand now said to be sulphured, must be put to the mixture of salt-petre and charcoal, and then stirred and turned about till the parts are thoroughly incorporated.

SECTION VI.

ROCKETS.

We come now to that part of our work which treats on the most beautiful of all Pyrotechnic productions.

Rockets have ever held the first place among single fire-works since the invention of the art; and to which they are justly entitled, both for the pleasing appearance they produce when fired by themselves, and the extensive application of them to increase the beauty of the other exhibitions.

They are called by the Italians _Rochette_ and _Raggi_; by the Germans _Raketen_ and _Drachetten_; by the French _Fusées_; and by the Latins _Rochetæ_; from which appears to be derived the name given them by the English; so much for their names:--as to their invention it is most probable that it took place at a very early period, if not among the first productions of the art. By the ancient Pyrotechnicians, they were considered as the most difficult articles of manufacture, insomuch that it was the first task enjoined to the disciples of Prometheus,[8] or professors of the art; and the goodness of the article, furnished a criterion of their pretensions.

It is to be questioned whether the ancients had such a variety of these articles, as we now have; but it is pretty certain that they were well acquainted with the proper proportions of the moulds requisite for their manufacture, insomuch that in many of their treatises, we find them employing the most difficult mathematical calculations, and giving intricate algebraic formulæ, for the purpose of finding their true proportion; but many of such useless difficulties we shall endeavour to evade, and essay to render our explications familiar without wholly sacrificing scientific investigations.

Rockets consist of strong paper cylinders, which being filled with the proper composition rammed hard, and fire being applied to their apertures they are caused to ascend into the air, or in any required directions; they have generally a head fixed to them containing corn powder, sparks, and many other decorations, which, when the body of the Rocket is consumed, take fire, burst in the air, and produce a most beautiful appearance; these are called Sky-rockets. Others are made to run with great velocity along a line, and are therefore called Line-rockets, or Courantines. Some are fixed on the circumference, or on the axle of a wheel, and are denominated Wheel-rockets; while another kind have their cases made perfectly water-tight, and being filled with stronger composition, admit of being plunged in and under water without retarding their inflammation; these receive the significant appellation of Water-rockets.

1. _Sky-rockets._--Sky-rockets, in regard to size, are divided into three kinds, namely, those the calibre or internal diameter of which does not exceed that of a pound bullet; or having their orifice equal to a leaden bullet, which weighs exactly one pound; for the relative magnitude of Rockets is estimated by the diameter of lead balls or bullets, after the manner taught in the Article Gerbes. Those, therefore, the calibre of which does not exceed a pound bullet, are termed small-size Rockets; those whose calibre is from one to three pounds are of the middle size; and those whose calibres exceed the last dimensions, are termed Rockets of the largest size; or are named after their weight, estimated as above.

We now proceed to describe the moulds and apparatus requisite for making Rockets, for on the due proportion of which (as was before observed) depends much of the goodness of the article. These moulds are also requisite in order that any number of Rockets may be prepared of the same size and force. As Rockets are made of various sizes, it is evident that moulds of different diameters must be produced.

Fig. 1, plate 1, represents a mould made and proportioned by the diameter of its calibre, which is divided into equal parts and rendered into scale, by which the relative proportions may be understood, merely by a contemplation of the figure. Thus A B is the calibre, or diameter; C D its whole height, including the foot complete, and equal to eight diameters, as per scale: E is the thickness of the mould, and may be about half a diameter; it should be made of some hard wood, such as lignum vitæ, or box, and may be either ornamented or plain; F is an iron pin, which serves to fix the cylinder firm to its foot. Fig. 2, is the foot detached from the cylinder, and drawn in true proportion as per scale; G, H, I, J, is the base, and may be about one and half diameter high; K, the choak, which serves to connect the cylinder to the foot; L is the nipple, which is half a diameter high, and in thickness equal to the former, or five-eighths diameter; M is the piercer, whose height is three diameters and a-half from the nipple, and at the bottom one third or fourth diameter, from thence tapering to one-sixth diameter in thickness. This piercer should be of iron, and inserted firmly into the foot; its purpose is to preserve a vacuity in the centre of the charge, the nature of which we shall hereafter explain. Fig. 3, is a former in two pieces, connected by an iron pin, (in diameter equal to the bottom of the piercer,) to which both ends are rounded off, in order that the choak or contraction in the cartridge may be effected more easily; the diameter of this former must be the same as that of the nipple, or suppose the diameter of the mould be divided into eight equal parts, (which is done on one part of the scale,) then the diameter of the former must be equal to five of these parts.

The length of this former, or roller, is not particular, providing it be long enough to admit of good hand-hold in the rolling of the cases; the short part of the former A may be two diameters in length, and should have a line B marked round it in the middle, or one diameter from the end; the longer part may be seven or eight diameters, which will give good hand-hold in the rolling.

Fig. 4 and 5, are rammers, or drift pins, used in loading the cases, which must be pierced lengthwise to fit on to the piercer.

Fig. 4. The first rammer should be pierced the whole length of the piercer, the second rammer should be pierced one and a half diameter; when the case is loaded and rammed above the piercer, a short solid rammer must be used, and these rammers should be a little less than the former, to prevent injury to the inside of the cartridge, when driving in the charge. They should be made of some hard wood, and their extremities secured by ferrels of brass, or any other metal, which will keep them from splitting or extending: their lengths are of little consequence, providing they do not much exceed the relative depths of the cartridge; for, as the workmen say, the longer the rammer the less will be the pressure on the composition by the blow given by the mallet.

The proportion between the length of Rockets and their calibre, is not the same in Rockets of greater or less dimensions than those given above, but should vary nearly as their magnitude; that is to say, their length should be diminished as their calibre is increased. The length of the mould for small Rockets should be six times the calibre, but for Rockets of the mean and larger size, it will be sufficient if the length of the mould be five times, or even four times that of the calibre.

The following is a table computed to regulate the height and diameter of the mould according to the weight of the Rockets, when they are driven solid, or without the use of a piercer. It is extracted from an old treatise on fire-works by Lieutenant Robert Jones; and inserted for the assistance of those who may wish to construct Rockets without the piercer, a practice we would never recommend to those for whom our “Manual” is designed. To those who manufacture fire-works for sale it is certainly the most expeditious method to ram them solid, and with the machine to bore or pierce them afterwards; but to those who make Rockets for their own private recreation, it is by far the most eligible to load them over a piercer, for by the other method it will require a very expensive apparatus,[9] and at first more skill to use it than what the Tyro will possess, and at last he will never be certain that he has made a good article.

TABLE I.

DIMENSIONS OF ROCKETS.

Length of the Weight of moulds without Interior diameter Heights of the Rockets. their feet. of the moulds. nipples. 6 lbs. 34.7 inches. 3.5 inches. 1.5 inches. 4 do. 31.6 do. 2.9 do. 1.4 do. 2 do. 13.3 do. 2.1 do. 1.0 do. 1 do. 12.2 do. 1.7 do. 0.85 do. 8 ozs. 10.12 do. 1.3 do. 0.6 do. 4 do. 7.75 do. 1.12 do. 0.5 do. 2 do. 6.2 do. 0.9 do. 0.45 do. 1 do. 4.9 do. 0.7 do. 0.33 do. ½ do. 3.7 do. 0.55 do. 0.25 do. 6 drs. 3.5 do. 0.5 do. 0.22 do. 4 do. 2.2 do. 0.3 do. 0.2 do.

By this table we find that a six-pound Rocket rammed solid, must be thirty-four inches, seven-tenths in length; its external diameter three inches five-tenths or three and half inches, and the height of the nipple one inch and a-half. The diameter of the nipple in this and all other cases must be equal to that of the former, and in regard to its height I have never found it to answer better than when the cavity which it formed at the mouth of the Rocket was hemispherical, or equal in height to half its diameter.

We shall now, by the following table, shew the method of finding the calibre of Rockets according to their weight, which is computed by the principles already given; that is, a pound Rocket is such that its aperture will just admit a bullet of a pound weight, and so of the rest.

TABLE II.

OF THE CALIBRE OF ROCKETS OF A POUND WEIGHT AND BELOW.

16 ounces. 19½ lines.[10] 14 drams. 7¼ lines. 12 do. 17 do. 12 do. 7 do. 8 do. 15 do. 10 do. 6⅓ do. 7 do. 14¾ do. 8 do. 6¼ do. 6 do. 14¼ do. 6 do. 5⅔ do. 5 do. 13 do. 4 do. 4½ do. 4 do. 12⅓ do. 2 do. 3¾ do. 3 do. 11½ do. 2 do. 9⅙ do. 1 do. 6½ do.

The use of _this_ table will be easily understood, for, as in the first instance, if a Rocket of 16 ounces ought to be nineteen and a-half lines in diameter, one of 12 must be 17 lines, one of 8 ounces 15 lines, one of 8 drams six and a-quarter lines; and so of the others.

If the diameter of the Rocket be given, we can as easily, by the reverse method, find the weight of the ball corresponding to that calibre. For example, if the diameter be 15 lines, it will be immediately seen, by seeking for that number in the column of lines, that it answers to a ball of eight ounces.

As the foregoing table extends only to Rockets of 16 ounces, or one pound, and from that downwards, the following will be found equally useful for those of superior dimensions.

TABLE III.

OF THE CALIBRE OF MOULDS FROM 1 TO 57 POUNDS BALL.