VII. OF ROCKETS AND THEIR APPENDAGES
A rocket is a flying fusée, (Fusées Volantes of the French), formed with paper, of a cylindrical shape, and filled with a composition of certain inflammable substances, being pierced in the diameter of its length. It is furnished with a stick, serving as a counter-weight, or balance, to guide it vertically in its ascension. It carries generally different garnishes, or furniture; as stars, serpents, fire-rains, marrons, meteors &c. which are thrown off, and produce an elegant appearance, when it terminates its flight.
Rockets have been applied to several uses. Thus, the war-rocket, as an incendiary, improved by Congreve, and the signal rocket, are some of its applications. These, however, are modified for the purpose, and will be spoken of hereafter. The Indian rockets, called Fougette (Baguette à feu of the French) will also be noticed.
Although as a fire-work for exhibition, the rocket may be considered the most grand, and, especially when furnished with various decorations, the most brilliant, yet its utility for Military and Naval purposes is acknowledged by all.
When treating of sundry preliminary operations in the second part of this work, we had occasion to introduce the subject of rockets, as respects the formation of their cases, the manner of charging and driving them, with the tools required, and the boring of rockets, when they have been driven solid. These subjects may be found in sections iv, v, and viii. We purpose, however, to make such observations as may, with the remarks heretofore offered, furnish the reader with a general knowledge of the making, decorating, and discharging of rockets. On the theory of the ascension of rockets, motion of fire-wheels, &c. and observations on the rocket principle, consult the chapter in the first part of the work, concerning the theory of particular fire-works. For the manner of uniting sheets of paper of several thicknesses, for cases, see Pasteboard.
Sec. I. Of the Caliber and Proportion of Rockets.
Sky-rockets are generally made of seven calibers, from half an inch to three inches. Different opinions have been entertained respecting the proper proportions. Some contend that the height should be always regulated by their exterior diameter. On this subject, several experiments, it seems, have been made by an experienced artist, M. Morel, not only to determine the length, which is best calculated to produce the maximum of ascension, but also with respect to the length compared with the caliber of the case.
The following tables are necessary in the formation of rockets. The first shows the size of the caliber of the mould, for rockets of a pound weight, and below; and the second points out the size required for the caliber of moulds, from one pound to fifty pounds. A lb. rocket, it must be observed, is that which is just capable of admitting a leaden bullet of a pound weight, and so of the rest.
TABLE I. Size of the caliber of moulds of a pound weight, and below to an ounce.
+----------+----------+ |Weight of | | |Rockets in| Diameters| |ounces. | in lines.| +----------+----------+ | 16 | 19½ | | 12 | 17 | | 8 | 15 | | 7 | 14¾ | | 6 | 14¼ | | 5 | 13 | | 4 | 12⅓ | | 3 | 11½ | | 2 | 9⅙ | | 1 | 6½ | +----------+----------+
Here, it is evident, that the mould of a rocket of twelve ounces in weight, ought to be seventeen lines (12 lines to the inch) in diameter; and one of five ounces, will require a mould of thirteen lines in diameter. Hence, we derive an easy method of finding the size, when the weights are given: and, if the diameter of the rocket be given, it will be equally easy to find the weight of the ball, corresponding to the weight of that caliber.
TABLE II. Size of the caliber of moulds, of from one to fifty pound ball.
------+---------+------+---------+------+---------+------+--------- Pounds| Caliber |Pounds| Caliber |Pounds| Caliber |Pounds| Caliber ------+---------+------+---------+------+---------+------+--------- 1 | 100 | 14 | 241 | 27 | 300 | 40 | 341 2 | 126 | 15 | 247 | 28 | 304 | 41 | 344 3 | 144 | 16 | 252 | 29 | 307 | 42 | 347 4 | 158 | 17 | 257 | 30 | 310 | 43 | 350 5 | 171 | 18 | 262 | 31 | 314 | 44 | 353 6 | 181 | 19 | 267 | 32 | 317 | 45 | 355 7 | 191 | 20 | 271 | 33 | 320 | 46 | 358 8 | 200 | 21 | 275 | 34 | 323 | 47 | 361 9 | 208 | 22 | 280 | 35 | 326 | 48 | 363 10 | 215 | 23 | 284 | 36 | 330 | 49 | 366 11 | 222 | 24 | 288 | 37 | 333 | 50 | 368 12 | 228 | 25 | 292 | 38 | 336 | | 13 | 235 | 26 | 296 | 39 | 339 | | ------+---------+------+---------+------+---------+------+---------
By this second table, if the weight of the ball be given, the size of the mould may be found: suppose it be eighteen pounds; opposite to it is the number 262. Then we say, by the rule of proportion, (as 19-1/2, see Table 1, is supposed to be divided into a hundred parts) 100 : 19-1/2 : : 262 to the fourth term sought, viz. 51.09; which gives for the required caliber 52 lines nearly, or four inches and four lines. But if the caliber be given in lines, the weight of the ball may be found: suppose the given caliber be 36 lines, then as 19-1/2 : 100 : : 36 : 184. The nearest number in the table to this is 181, which shows that the weight of the ball will be rather more than 6 lbs; or, in other words, that a rocket, the diameter or caliber of which is thirty-six lines, is a rocket of a 6 lb. ball. See Congreve Rocket.
As to moulds to prevent the rockets from splitting in the act of charging them, Morel observes, that he has never used them. He remarks, that a case which will not resist the force of the charge, cannot resist the violence of the fire.
On the subject of compositions, he observes, that he has only employed one formula, and, of course, but one standard proportion for all sized calibers; and is of opinion, that it is useless to employ an inferior composition, or one with which we are unacquainted, when we have a formula, on which we may rely. This opinion, however, does not agree with that of others.
Certain rockets, it is to be remarked, show tails of fire in their flight, and others again do not. This depends entirely upon the charcoal; for, if we use charcoal, made from tender and light wood, it burns rapidly, without producing a tail of fire; but if we use the charcoal of oak or of beech, or of other hard wood, the rocket will form a brilliant tail of fire, during the whole period of its ascension. It is said, however, that the charcoal of light wood, is lighter and more inflammable, and for that reason, better calculated for rockets; but, so far from producing the effect, we have mentioned, a quick combustion ensues, leaving no ignited coal to be acted upon by atmospheric air.
It is found by experiment, that even a little more or a little less powder, gives to or takes from, the composition its effective power; and, therefore, that the rockets, in their flight, ascend to a greater or less height.
Some writers have asserted, that powder ought not to enter into the composition of rockets; but in lieu thereof, only its component parts. Where, we may inquire, is the difference? The reason, however, assigned, is, that rockets made with gunpowder and the other substances, will not keep any time, owing to the powder becoming damp, and the composition spoiled. But rockets which have been made in France and carried to the East Indies, and brought back, were found, on trial, not to have lost any of their effect.
Different opinions have also been entertained, respecting the composition for the charging of rockets. Some, it appears, would employ a composition for each rocket, according to its caliber, pre-supposing, that the inflamed matter acquired force by the increase of its volume; without considering, that a large rocket has more weight than a small one, and requires more power to raise it. Experience has demonstrated, that a composition which will completely raise a rocket of three-quarters of an inch, will raise, under the same circumstances, a rocket of three inches; and, on the contrary, that the last will ascend more slowly, in consequence of having to encounter a greater resistance in the air, owing to its size.
Sec. II. Of the Composition of Sky-rockets, and Observations on its Preparation, and on other Subjects respecting Rockets.
The formulæ we here give, which we notice separately from the others, are on the authority of Morel, who, by experience, has found them to excel all others. Nevertheless, we purpose to enumerate other formulæ for the information of the reader.
Composition of Sky-Rockets, according to Morel.
For Summer. Another.
1. Saltpetre, 17 oz. 2. Saltpetre, 16 oz. Sulphur, 3½ -- Sulphur, 4 -- Meal-powder, 1½ -- Charcoal, 7½ -- Charcoal of oak, 8 --
For Winter. Another.
3. Saltpetre, 17 oz. 4. Saltpetre, 44 oz. Sulphur, 3 -- Sulphur, 4 -- Meal-powder, 4 -- Charcoal, 16 -- Charcoal of oak, 8 --
Another. Another.
5. Saltpetre, 16 oz. 6. Sulphur, 3 oz. Sulphur, 2 oz. 3 drachms. Saltpetre, 20 -- Charcoal, 6 oz. Charcoal, 8½ --
Chinese Composition for rockets of honour.
Saltpetre, 5 ounces. Sulphur, 1¼ ---- Charcoal, 2½ ---- Meal powder, 1 ---- Pulverized cast iron, 2½ ----
Two compositions for rockets of any caliber are given by Bigot; (p. 122); viz.
Rockets of Honour.
Meal powder, 2 parts. Saltpetre, 10 ---- Sulphur, 2½ ---- Charcoal, 5 ---- Cast iron, pulverized, 5 ----
Particular Composition.
Saltpetre, 16 parts. Sulphur, 4 ---- Charcoal, 9 ---- Antimony, 2 ----
In the old authors on fire-works, there are a variety of formulæ for sky-rockets, which will be found in the following table:
------------------+------+------+------+------+------+----------------- Kinds of Rockets.| Meal |Salt- |Char- |Steel |Sul- | REMARKS. |powder| petre| coal | | phur | ------------------+------+------+------+------+------+----------------- |lb.oz.|lb.oz.|lb.oz.|lb.oz.|lb.oz.| Rockets, 4 oz. | 1 4 | 0 4 | 0 2 | 0 0 | 0 0 | Do. 8 oz. | 1 0 | 0 4 | 0 1½| 0 0 | 0 3 | Do. do. | 1 8 | 0 0 | 0 4½| 0 0 | 0 0 | Do. 1 lb. | 2 0 | 0 8 | 0 2 | 0 1½| 0 4 | Do. in general, | 0 0 | 4 0 | 1 8 | 0 0 | 1 0 | Do. do. | 0 2 | 4 0 | 1 12 | 0 0 | 1 8 | Do. large fly, | 1 0 | 4 0 | 0 0 | 0 0 | 1 0 | Do. of a middling | 3 0 | 8 0 | 0 0 | 0 0 | 3 0 | size | | | | | | Do. do. | 1 0 | 3 0 | 1 0 | 0 0 | 2 0 | Do. water, | 6 0 | 4 0 | 5 0 | 0 0 | 3 0 | The proportion of | | | | | |charcoal is cer- | | | | | |tainly too great. Do. do. | 0 0 | 1 0 | 0 6 | 0 0 | 0 4½| Do. do. | 0 0 | 1 0 | 0 12 | 0 0 | 0 4 | Do. do. | 0 0 | 4 0 | 1 12 | 0 0 | 1 8 | Do. do. | 4 0 | 4 0 | 0 0 | 0 0 | 2 0 | Do. do. | 0 4 | 1 0 | 0 2 | 0 0 | 0 8½| Do. do. | 1 0 | 3 0 | 0 8½| 0 0½| 1 0 | Sea-coal, 1 oz. | | | | | |saw-dust, ¾ oz. | | | | | |coarse char. ¼ oz. Do. do. | 1 12 | 3 0 | 0 12 | 0 0 | 1 8 | Sawdust, 2 oz. Do. do. sinking}| 0 8 | 0 0 | 0 12 | 0 0 | 0 0 | charge, }| | | | | | ------------------+------+------+------+------+------+-----------------
The charcoal ought not to be pulverized very fine. It should be passed through a coarse wire sieve, and the impalpable powder then separated, by submitting the sifted charcoal to the same operation in a finer sieve. The fine charcoal may be used for small fire-works.
The instructions, heretofore given, for the mixture of compositions must be attended to; as, for instance, when we have weighed the powder, nitre, and sulphur, the whole are to be incorporated in a mortar, and then passed three times through a large sieve. Afterwards add the charcoal, which is mixed thoroughly with the hand. (See the Mixture of Substances, part second). With respect to the rammers, the mode of charging, &c. see section iii, of part second.
In charging cases of half an inch caliber, fifteen blows with the mallet must be given; for three-quarters of an inch, twenty blows; for one inch, twenty-five blows; for one and a quarter inches, thirty blows; one and a half inches, thirty-five blows; for two inches, forty blows; and for three inches, fifty blows;--that is to say, the number of blows must be given to each charge put in, which ought to occupy half the interior diameter of the case. The rammer must be frequently taken out, and struck, so as to disengage any of the composition, which may adhere to it. Respecting the accuracy of the charge, see Table rocket, in the chapter on Table fire-works.
The garnishing, or furniture, should not exceed, in any case, one-third the weight of the rocket. The head is made of pasteboard, first moistened, and then rolled round a conical former. It must enter the mould, and, when inserted, ought to be pasted round the juncture with paper. (See sec. iii, and iv.)
With respect to rocket sticks, as they are used for counter-weights, Morel remarks, that, for rockets up to an inch and a quarter, they may be formed of the branches of light wood, as hazle, elder, &c. and for rockets above that caliber, heavy wood, but perfectly straight and without knots, may be used. As a general rule, the sticks are made ten or twelve times the length of the rocket, and in thickness about one-third of the exterior diameter of the case. In the large end of the stick, there is a gutter or groove, formed to receive the rocket. When branches are used, they must also lie straight, and cut flat at the large end, about half their thickness, so that they may be joined to the rockets with a pack-thread, or fine iron wire. If the stick is too weighty, it may be shaved off the whole length. Rockets, we may remark, that are not well balanced by the stick, will not ascend regularly. If the stick be too light, they will rise in a zigzag direction; but, if too heavy, their accelerated force will be diminished, their motion slow, and, when they arrive at a certain height, they will fall in a semicircular position. (See section v, of this chapter, on the Dimensions and Poise of rocket sticks.)
We may further remark, that all rockets are formed and proportioned by the diameter of their orifice. When the height is six and two-thirds diameter, the foot should be one diameter and two-thirds. The choak of the mould, if used, is one diameter and one-third in height, which must be made out of the same piece as the foot, and fit tight in the mould. There must be an iron pin to keep the foot fast. The nipple is half a diameter high, and two-thirds thick, and made of the same metal as the piercer. The height of the piercer is three and a half diameters, and at the bottom one-third of a diameter thick, and from thence tapering to one-sixth of a diameter. The best mode of fixing the piercer in the cylinder, is to make that part below the nipple sufficiently long to go entirely through the foot, and rivet at the bottom. The former or roller, for the cases, is seven and a half diameters from the handle, and its diameter is two-thirds of the bore. The end of the former is one diameter and two-thirds long, and of the thickness given above. The small part, which fits in the hole in the end of the roller, when the case is pinched, is one-sixth and one-fourth of the diameter of the mould thick. The first drift, or rammer, must be six diameters from the handle; and this, as well as all other rammers, must be a little thinner than the former, to prevent the sacking of the paper, when the charge is driven. In the end of this rammer must be a hole to fit over the piercer. Several hollow rammers are used in completing the charge. (See our remarks in part second on Charging of cases.)
The diameter of the nipple should always be equal to that of the former. With regard to the thickness of moulds, it is immaterial, provided they are substantial and strong. Solid driving is more expeditious than charging over a piercer; but great labour and attention is required in boring them, an account of which, with the apparatus required, may be seen in Part second.
The following table of the dimensions of rocket-moulds, if the rockets are rammed solid, may be useful.
-----------+---------------+-----------------+-------------- |Length of their| | Weight of |moulds without |Internal diameter|Height of the rockets. |their feet. | of the moulds. | nipples. -----------+---------------+-----------------+-------------- lbs. oz. | Inches. | Inches. | Inches. -----------+---------------+-----------------+-------------- 6 0 | 34.7 | 3.5 | 1.5 4 0 | 38.6 | 2.9 | 1.4 2 0 | 13.35 | 2.1 | 1.0 1 0 | 12.25 | 1.7 | 0.85 0 8 | 10.125 | 1.333 &c. | 0.6 0 4 | 7.75 | 1.125 | 0.5 0 2 | 6.2 | 0.9 | 0.45 0 1 | 4.9 | 0.7 | 0.35 0 0½ | 3.9 | 0.55 | 0.25 6 drachms.| 3.5 | 0.5 | 0.225 4 drachms.| 2.1 | 0.3 | 0.2 -----------+---------------+-----------------+--------------
Sec. III. Of the Heading of Rockets.
The heads for sky-rockets must always bear a given proportion to the rockets.
A pointed cap, adapted to the summit, will make a rocket ascend to a greater height, as it serves to facilitate its passage through the air. To these rockets may be added several other things; as a petard, which is a box of tin plate, filled with fine gunpowder, placed on the summit. The petard is put on the composition, at the end, when it has been filled, and the remaining paper of the cartridge is folded down over it, to keep it firm. The petard produces its effect, when the rocket is in the air, and the composition is consumed. We have already remarked, that the upper parts of rockets, that is to say, their heads, are generally furnished with some composition, which takes fire, when it has reached its greatest height, emits a considerable blaze, or produces a loud report and whizzing noise. Of this kind are saucissons, marrons, stars, showers of fire, &c. The heads of sky-rockets, are, therefore, furnished with a variety of compositions.
When a rocket is five diameters, and one-sixth in length, the case being cut to this length, after it is filled, the head should be two diameters high, and one diameter 1/6th, and 1/2 in breadth. The perpendicular height of the cone, or cap of the head, must be in diameter, one, and one-third. There is a circular collar, to which the head is fixed, turned out of any light wood; its exterior diameter must be equal to the interior diameter of the head. One-sixth is sufficient for its thickness, and round the outside must be a groove. The interior diameter of the collar should not be quite so wide as the exterior diameter of the rocket. When it is to be glued on the rocket, two or three rounds of paper are to be cut off, which will make a shoulder for it to rest upon. Two or three rounds of paper well pasted, will be sufficient for the head. Put the collar on the mandril, or former, which must fit the inside of the cone when formed; then, with a pinching cord, pinch the bottom of the head into the groove, and tie it with small twine. To make the caps, cut the paper in round pieces, equal in diameter to twice the length of the cone, which is to be made. These pieces, being cut into halves, will make two caps each. Paste over the caps a thin white paper, which must be a little longer than the cone, so as to project about half an inch below the bottom: this projection of paper being matched and pasted, serves to fasten the cap to the head, A conical former is used to shape the head.
Sec. IV. Of the Decorations for Rockets, and the Manner of filling their Heads.
Having, in the preceding section, shown the mode of forming heads, or conical caps, for rockets, we may now remark, that the furniture or decorations for rockets consist of stars of different kinds, such as tailed, brilliant, white, blue, yellow, &c. or gold and silver rain; or serpents, crackers, fire-scrolls, or shining marrons, or small rockets; the kind of the decoration depending entirely upon taste and fancy.
In loading the heads of rockets, a ladleful of powder must be put into each head, along with the decorations. This is absolutely necessary in order to burst the head and disperse the stars, &c.
Various experiments have been instituted, to make rockets, by employing sundry compositions for charging the cases, along with the rocket composition, to produce, like the heads of rockets, when they burst, different appearances. M. Morel informs us, that he made several experiments with that view, but did not succeed. He ascribes the failure to several causes; and, in substance, concludes, that such figures have a greater weight than rockets are able to carry; that their irregular forms and movements produce, in the ascension, a contrariety of effects, which impedes their flight; and that, if they were to succeed, the rapidity, with which the fuse passes through the air, would prevent any thing being distinguished. As such exhibitions are shown with effect, by the bursting of the head of the rocket, after it has ceased to burn; we are of opinion, that the only mode, which can be adopted, with success, is the one already described. For after the rocket has ceased, or finished, the last portion of fire is communicated to the head, containing the decorations, which is blown off, and its contents are inflamed and dispersed. It is true, however, that, in some compositions, stars, previously made, and therefore not mixed with the composition, are put in the cases along with the charge: We have an instance of this in the fire-pump, Roman candle, &c. The cases for these are filled in the following order: first with gunpowder to a certain extent, then a star, then composition; then powder again, then another star, and so on alternately, until the charge is completed; but, in this instance, the star, as well as the gunpowder, is distinct from the composition, which forms the fire-pump. For, while the composition performs one part, the gunpowder acts another, by throwing the stars out, which, by their combustion, give the appearance they are intended to produce. Stars may be formed, or rather exhibited, in this way, which, in fact is much after the manner, in which they are used for the heads of rockets. But the experiments of Morel appear to have been made, with a view to produce that effect from the rocket itself, and altogether by the composition, by varying or otherwise modifying it. Star-composition, it must be observed, is of a greater specific gravity than any ordinary composition, in consequence of the weight, and quantity of metallic and other substances, which enter into it. By arranging stars in cases, in the mode described for the fire-pump, the effect, we have spoken of, always takes place. In rockets, however, which require to be driven with considerable force, and over a piercer, they could not be used.
Sec. V. Of the Dimensions and Poise of Rocket-sticks.
Although we have made some observations on the size, as well as the use of rocket-sticks, in a general way; yet the subject being very important, as rockets, however well made, cannot take a vertical direction without them, we subjoin the following table, which exhibits, at one view, the length, &c. of the stick, compared with the weight of the rocket, and the poise it must necessarily have from the point of the cone. The centre of gravity is a necessary consideration.
---------+------------+-----------+---------+-----------+------------- Weight | | | | | Poise from of the | Length of | Thickness | Breadth | Square at | the point of rocket. | the stick. | at top. | at top. | bottom. | the cone. ---------+------------+-----------+---------+-----------+------------- lbs. oz. | Ft. In. | Inches. | Inches. | Inches. | Ft. In. ---------+------------+-----------+---------+-----------+------------- 6 0 | 14 0 | 1.5 | 1.85 | 0.75 | 4 1.5 4 0 | 12 10 | 1.25 | 1.40 | 0.625 | 3 9. 2 0 | 9 4 | 1.125 | 1. | 0.525 | 2 9. 1 0 | 8 2 | 0.725 | 0.80 | 0.375 | 2 1. 0 8 | 6 6 | 0.5 | 0.70 | 0.25 | 1 10.5 0 4 | 5 3 | 0.3750 | 0.55 | 0.35 | 1 8.5 0 2 | 4 1 | 0.3 | 0.45 | 0.15 | 1 3. 3 1 | 2 6 | 0.25 | 0.35 | 0.10 | 11 0. 0 0½ | 2 4 | 0.125 | 0.20 | 0.16 | 8 0. 0 0¼ | 1 10½ | 0.1 | 0.15 | 0.5 | 5 0.5 ---------+------------+-----------+---------+-----------+-------------
** Transcriber Note: the last three rows of this table have many typos. The rows were probably intended to be as follows:
0 1 | 2 6 | 0.25 | 0.35 | 0.10 | 1 1. 0 0½ | 2 4 | 0.125 | 0.20 | 0.16 | 0 8. 0 0¼ | 1 10½ | 0.1 | 0.15 | 0.5 | 0 5.5 ---------+------------+-----------+---------+-----------+------------- ** end of Transcribers Note **
The last column expresses the distance from the top of the cone, where the stick, when tied on, should balance the rocket, so as to stand in equilibrium on the edge of a knife.
Having given the method of preparing sticks, nothing more is necessary on that head, except that they should be cut and planed according to the dimensions in the table. A groove must be made the length of the rocket, and as broad as the stick will allow. Two notches may be cut on the opposite flat side, for the cord which ties on the rocket. The top of the stick should always touch the head. In fixing on the stick, care must be taken to secure it well.
It is the stick which gives a proper counterpoise, without which the rockets would not ascend; and, unless they were of a proper length and weight, instead of taking a vertical or perpendicular direction, they would describe a parabola, or take an oblique course, and fall to the ground.
A rocket stick may be made for any sized rocket, although not expressed in the table, by assuming the data there given, taking care to find the centre of gravity. For the sticks for war-rockets, see Congreve Rocket.
Sec. VI. Of the Mode of Discharging Rockets.
Having completely prepared the rockets with all their appendages, we consider in the next place the manner of discharging them; in performing which some care is to be observed. The old and heretofore common manner, of setting them off by hanging them on nails and hooks, has many objections. The best mode is to have a ring made of strong iron wire, large enough for the stick to go in, as far as the mouth of the rockets. Then let this ring be supported by a small iron, at some distance from the post or stand, to which it is fixed; and have another ring fixed in the same manner, to receive and guide the small end of the stick. Rockets, thus suspended, will have nothing to obstruct their flight. The upright, to which the rings are fixed by the small iron, must be exactly vertical.
Two, three, or more sky-rockets may be fixed on one stick, and fired together. Their appearance, in this case, is very striking. Their tails will seem but as one of immense size, and the discharge from so many heads, at the same time, will resemble more the effect of an air balloon. Rockets, for this purpose, must be made alike in every particular. If the rockets are half-pounders, whose sticks are six and a half feet long, then two, or three, or six of these are to be fixed to one stick, the length of which must be nine feet and three-quarters. Cut the top of it into as many sides as there are rockets, and let the length of each side be equal to the length of one of the rockets without its head; and in each of these sides, let a groove be made. From this groove, plane it round, down to the end. The rule is, that the stick at top must be sufficiently thick, when the grooves are cut, for all the rockets to lie as near as possible, without pressing each other. When only two rockets are to be fixed on one stick, let the length of the stick be the last given proportion, but shaped after the common method, and the breadth and thickness, double the usual dimensions.
When several rockets are placed upon one stick, there will be some danger of their flying up without the stick. Cases, when tied on all sides of the stick, cannot be secured to it by rope passing over notches as before mentioned. Instead of which, drive a small nail in each side of the stick, between the necks of the cases; and let the cord, which goes round their necks, be brought close under the nails. A quick match, without a pipe, is to be fixed to the mouth of one rocket, and carried to another. This match will communicate fire at one and the same time.
There is a mode of discharging sky-rockets without sticks, which consists in using balls of lead tied to a wire two or three feet long, and fixing the other end of the wire to the neck of the rocket. These balls answer the purpose of sticks, when made of a proper weight, which is about 2/3ds the weight of the rocket. They will balance the rocket at the usual point. To fire rockets, thus equipped, a different mode must be adopted. They are hung, one at a time, between the tops of wires placed for that purpose, letting their heads rest on the wire, and the balls hang down between them. The wires are about three feet long, and inserted in a circle, in a block of wood, which must lie level, and the wires perfectly vertical. The diameter of the circle is two and a half inches; it is divided into three equal parts, and at each one is a rod or wire.
We may introduce here a description of the stands for sky-rockets, and the girandole chests for the flights of rockets. The first is formed of two rails of wood, of any length, supported at each end by a perpendicular leg, so that the rails lie horizontal; and let the distance from one to the other be almost equal to the length of the sticks of the rockets, intended to be fired. Then in the front of the top rail, drive square hooks at eight inches distance, with their points turning sidewise; so that, when the rockets are hung on them, the points will be below the sticks, and keep them from falling or being blown off by the wind. At the front of the rail at the bottom must be staples, driven perpendicularly under the hooks at top. Through these staples put the small ends of the rocket-sticks. They are fired by applying a lighted port-fire to their mouths. Two or three seconds will expire before they ascend.
The girandole chest is composed of four sides of equal dimensions; but may be made of any size, according to the number of rockets to be fired. Its height must be in proportion to the rockets, and higher than the rockets with their sticks. When the sides are joined, fix in the top, as far down the chest as the length of one of the rockets with its cap on. On this top, make as many square or round holes, to receive the rocket-sticks, as the number of rockets to be fired; but let the distance between them be sufficient to prevent their touching each other. From one hole to another cut a groove of a sufficient size for a quick match to lie in. The top being thus fixed, put in the bottom, at about 1-1/2 feet distance from the feet of the chest. In this bottom, make as many holes as at the top, and all to correspond, but not so large as those in the top.
To prepare the chest, a quick match is laid in all the grooves, from hole to hole. Then take the sky-rockets, and prime them with meal-powder, or priming paste, as before-mentioned, and put a bit of match up the cavity of each, which should project out. Put the sticks of the rockets through the holes in the top and bottom of the chest, so that their mouths may rest on the quick match in the grooves. The rockets will then be fired at once. There should be a door in the side of the chest, and also a cover, to secure the rockets until they are required.
The fountain of rockets, an exhibition which frequently accompanies a display of works, is nothing more than a number of rockets discharged at the same time.
There are some improvements on the girandole chest, and on the different modes of discharging a series of rockets.
We may mention one contrivance for this purpose, as described by Morel. It is an oblong box furnished with a double lid, which, when shut, resembles the roof of a house. This box is sixty inches in length, ten inches in breadth, and nine inches in height. It rests upon a frame, and has a bottom in which are one-hundred holes, to receive the same number of rocket-sticks, the rockets resting on the bottom of the box. The lid serves to prevent the access of moisture, and to secure the rockets. No part of the rocket is seen in the box. They are set off by first strewing meal-powder on the bottom, which is then in contact with their mouths, and applying a lighted port-fire. They rise out of the box all together, and at the same time. When fired together, so as to form a flight of rockets, the French use them of three-quarters of an inch caliber.
The girandole may be considered an assemblage of a large number of rockets of various calibers, arranged in gradation; the largest, occupying the first range, &c. The girandole constitutes, as a fire-work, in the language of Morel, the feux de gouvernement.
Similar to this is a contrivance for the same purpose, but not so extensive, and rather differently formed. It consists of a case, in which there are holes to receive the sticks and support the rockets. The case is supported by legs; two of which, working upon a joint, may be extended, and thus the rockets be made to move in any angular direction. The inclination given is hardly ever more than 55 degrees. The legs are pointed, so as to retain their position. If the rockets are to ascend vertically, the two legs, which move in a joint, are closed. They are stuck in the ground at the same place.
For the mode of discharging the Congreve Rocket, see the article on Congreve Rockets.
Sec. VII. Of the Appendages, and Combinations of Rockets.
We purpose to notice, in this section, some of the modes of arranging, combining, and also of varying the effects of rockets.
When a sky-rocket is fixed with its stick on the top of another, a fresh tail of fire will be observable, when the second rocket takes fire, which will mount to a great height. The preparation of these rockets consists in filling a two pounder only half a diameter above the piercer, (which must be observed in this instance,) and its head with not more than ten or twelve stars; adapting a stick as usual, which must be made a little thicker than customary. This stick must be cut in half the way flat, and in each half a groove, so that, when joined together, they will receive, and be large enough to hold the stick of a half pound rocket. The heading is then performed as before described. The stick of this small rocket is to be fixed in the hollow of the large one, so far that the mouth of the rocket may rest on the head of the two pounder; and, from the head of the two pounder, a leader is to be carried into the mouth of the small rocket.
When sky-rockets are fixed one on the top of another, they are called towering rockets, on account of the great height to which they ascend. They are made in the following manner: Fix on a pound rocket, a head without a collar; then take a four-ounce rocket, which may be headed or bounced, and rub the mouth of it with priming paste, or meal-powder and spirits of wine. Put it into the head of a large rocket with its mouth downwards, previously, however, inserting a bit of quick match in the hole made through the clay of the pound-rocket, which match should be of a sufficient length to go a small distance up the bore of the small rocket, to fire it when the large one is burnt out. The four-ounce rocket being too small to fill the head of the other, roll round it as much tow as will make it stand upright in the centre of the head. Then paste a single paper round the opening of the top of the head of the large rocket. The large rocket must have only half a diameter of charge rammed above the piercer; for, if filled to the usual height, it would turn before the small one takes fire, and entirely destroy the intended effect. When one rocket is headed with another, there will be no occasion for any blowing powder; for the force with which it flies off will be sufficient to disengage it from the head of the first fired rocket. The sticks for these rockets must be a little longer than for those headed with stars, rain, &c.
The caduceus rockets are formed of two rockets. When attached, one on each side at the top of the stick, they form a right angle, their mouths being equidistant from the stick. The sticks, for this purpose, must have all their sides alike, which should be equal to the breadth of a stick, proper for a sky-rocket of the same weight as those intended to be used, and to taper downwards as usual. They must be long enough to balance them, and one length of a rocket from the cross-stick. The cross-stick is that to which the cases are tied, and serves to preserve them steady in that position. Each rocket, when tied on, should form either an angle of 45, or 60 degrees with the large stick, or both together an angle of 90 or 120 degrees. The last, however, is considered a preferable angle. When tying on the rockets, attention ought to be paid to place their heads on the opposite sides of the cross-stick, and their ends on the opposite sides of the long stick. Quick-match is then to be carried from the mouth of one into that of the other. When these rockets are to be fired, suspend them between two hooks or nails, and apply fire to the leader in the middle, and both will take fire at the same time.
The particular effect of this rocket is, that, in rising, it forms two spiral lines, or double worms, in consequence of their oblique position; and the counterpoise in the middle (the stick) causes them to ascend vertically. Rockets, for this purpose, must have their ends choaked close, without either head or bounce; for a weight at top would be an obstruction to their mounting. They do not rise so high as single rockets, because of their serpentine motion, and the resistance they meet with in passing through the air. This resistance is greater than two rockets of the same size fired singly.
Honorary rockets are nothing more than sky-rockets, except that they carry neither head nor report. They are closed at top, to which is attached a cone. On the case, close to the top of the stick, a two-ounce case is tied. This last is filled with a strong charge, and is usually about five or six inches in length, and pinched close at both ends. At the opposite sides, at each end, a hole must be bored, in the same manner as in tourbillons; and from each hole, a leader must be carried into the top of the rocket. When the rocket is fired, and has arrived at its proper height, it will communicate fire to the case at the top, which will cause the rocket and stick to descend very fast to the ground, and, in its descent, will represent a worm of fire.
There are several modes of placing the small case, so as to produce the best effect. One is by letting the stick rise a little above the top of the rocket, and tying the case to it, so as to rest on the rocket. These rockets are not furnished with cones. Another method is also recommended; namely, in the top of the rocket, fix a piece of wood, in which drive a small iron spindle; then make a hole in the middle of the small case, through which put the spindle, and fix, on the top of it, a nut, to keep the case from falling off. The case, by this means, will turn very fast, without the rocket. This method, however, is not preferred.
One-pound rockets are considered the best size for this purpose.
Chained rockets, as they are sometimes called, are another modification of the manner of fixing rockets; for the intention is to make several sky-rockets rise in the same direction, and equally distant from each other. This effect is produced in the following manner: Take six, or any number of sky-rockets, of any size; then cut some strong pack-thread into pieces of three or four yards long, and tie each end of these pieces to a rocket in this way;--after tying one end of the pack-thread round the body of one rocket, and the other end to another, take a second piece of pack-thread, and make one end of it fast to one of the rockets already tied, and the other end to a third rocket; so that all the rockets, except the outside, will be fastened to two pieces of pack thread. The length of thread, from one rocket to the other, is indeterminate. They must all be of a size, and their heads filled with the same weight of stars, or other decorations.
In the mouth of each rocket, a leader is to be fixed of the same length, and when fixed, they may be hung almost close. Tie the ends of the leaders together, and prime them: When this is fixed, all the rockets will mount at the same time, and separate as far as the strings will admit. They will preserve the same order and distance, if they are rammed alike, and equally well made.
The manner of dividing the tail of a sky-rocket, so as to form an arch when ascending, is thus performed. Having some rockets made, and headed according to fancy, and tied on their sticks, get some sheet tin, and cut it into round pieces of about three or four inches in diameter. Then, on the stick of each rocket, under the mouth of the case, fix one of these pieces of tin, sixteen inches from the head of the rocket, and support it by a wooden bracket as strong as possible. The use of this is, that, when the rocket is ascending, the fire will play with great force on the tin, which will divide the tail in such a manner, as to form an arch. If there is a short piece of port-fire, of a strong charge, tied to the end of the stick, it will add greatly to the appearance; but this must be lighted before fire is put to the rocket.
Sec. VIII. Of Swarmers, or Small Rockets.
Although swarmers are nothing more than rockets of a smaller size, as from two ounces downwards, and are charged with the usual rocket composition, which we have described; yet it may be necessary to make some remarks respecting them.
Swarmers are sometimes fired in flights, or in a volley, and in large aquatic fire-works. They are bored in the same manner as large rockets, or pierced in the act of charging them. This is the case with those of one and two ounces. All rockets, however, under one ounce, are not bored, but must be filled to the usual height with composition. The number of strokes for ramming these small swarmers is not material, provided they are rammed true and moderately hard. The necks of unbored rockets must be in the same proportion as in common cases. The composition, with which small swarmers are charged, generally consists of
Meal-powder, 4 oz. Charcoal, or steel-dust, ¼ oz.
As to the swarmers which are pierced, or bored, viz. those of one and two ounces; they are made, we observed, in the same manner as large rockets, with the exception, that, when headed, their heads must be put on without a collar. The number of strokes for driving one-ounce cases must be eight, and for two-ounce, twelve.
Sec. IX. Of Scrolls for Sky-Rockets, and of Strung, Tailed, Drove, and Rolling Stars.
We have given, in a preceding chapter, the composition of various stars, which are used for the decoration of sky-rockets, and other species of fire-works. We shall, therefore, confine ourselves to their application, and the different modes of preparing them for this purpose.
Scrolls are used as furniture, or decorations for sky-rockets, and are so named from the spiral form they assume, when fired very quick in the air. We may put into the head of a rocket, as many of the cases as it will contain. Cases for scrolls should be four or five inches in length, and their interior diameter, three-eighths of an inch. One end of these cases must be pinched quite close before it is filled; and, when filled, the other end must also be closed. Then, in the opposite sides, make a small hole at each end, in the same manner as in tourbillons, and prime them with priming paste, or meal-powder and brandy.
Strung Stars, so named from having a cotton quick match run through them, are formed by taking some thin paper, and cutting it into pieces of about one and a half inches square, and laying on each piece, as much dry star composition as the paper, when folded, will easily contain. The paper, with its contents, is then twisted up as hard as possible. When done, rub some paste between the hands, and roll the stars between them, and afterwards dry them. They are then covered with tow, and primed with a paste composed of meal powder, and brandy, in which they may be rolled in the same manner as described when treating of stars. They are then dried and strung on cotton quickmatch, by piercing a hole through them, taking care to put but ten or twelve on each match, and placing them at the distance of three or four inches apart.
Tailed stars are those which produce a great many sparks, representing a tail like that of a comet. Of these, there are two kinds, the rolled and the drove. The operation for the rolling of stars, we have sufficiently explained; it consists in mixing the composition with brandy, or, if it can be had, with spirit of wine, and either weak gum water, or isinglass size, sufficient to make a thick paste; and then rolling it.
When tailed stars are to be driven, the composition must be moistened with spirit of wine, or if it cannot be had, with fourth proof brandy, without the gum, or gelatin, and not made so wet as for rolling. One or two-ounce cases, rolled dry, are best for this purpose; and when they are filled, unroll the cases within three or four rounds of the charge, and all that is unrolled must be cut off. Then paste down the loose edge; and in two or three days afterwards, cut them in pieces of five or six-eighths of an inch in length; then melt some wax, and dip one end of each piece into it, so as to cover the composition. The other end must be covered with priming paste.
Drove stars are so designated, because the composition is always drove, and used in cases. They are seldom put in rockets, but are chiefly used for air-balloons. They are put in cases, to prevent the composition from being broken, by the force of the blowing powder in the shell. See Air-Balloons.
With respect to rolling stars, we gave, in our chapter on star compositions, not only the proportion of their constituent parts, but ample instructions for preparing them for use. They are usually about the size of a musket ball; but sometimes they are made an inch in diameter. When very small, they are called sparks. See Stars.
Sec. X. Of Line-Rockets and their Decorations.
Line-rockets are the same as the courantines of the French, or rockets that fly along a rope. If a rocket be attached to an empty case, and a rope passed through the latter, and stretched horizontally; and if the rocket be then set on fire, it will run along the rope, without stopping till the matter it contains is exhausted.
Line-rockets do not differ materially from sky-rockets, as they are made and driven like them; but they are without heads, and the cases are cut close to the clay. They are sometimes made with six or seven changes. Four or five, however, are the most common. We must first have a piece of light wood, turned round, about two and a half inches in diameter, with a hole through the middle, lengthwise, and sufficiently large for a wire to go easily through. If four changes are required, four grooves must be cut in the swivel, one opposite the other, to lay the rockets in.
Having rubbed the mouths of the rockets with wet meal powder, lay them in the grooves, head to tail, and tie them fast. From the tail of the first rocket, carry a leader to the mouth of the second, and from the second to the third, and so on to as many as there are on the swivel, making every leader very secure; but in fixing these pipes, care must be taken, that the quick match does not enter the calibers of the rockets. The rockets being fixed on the swivel and ready to be fired, have a line, 100 yards long, stretched, and fixed up tight, at any height from the ground, but placed perfectly horizontal. This length of line will answer for half-pound rockets, but, if larger, the line must be longer. One end of the line, before it is put up, is to be put through the swivel; and when the line-rocket is fired, let the mouth of that rocket, which is set off first, face that end of the line where the operator stands, and the effect will follow in succession, viz: the first rocket will carry the rest to the other end of the line, the second will bring them back, and they will continue running out and in, according to the number of rockets. At each end of the line, there must be a piece of wood for the rocket to strike against, to prevent injury to the line. Let the line be well soaped, and the hole in the swivel very smooth.
In order to vary the appearance, different decorations may be used with the line-rockets; of these, flying dragons, Mercuries, &c. are the most conspicuous. Another motion may be given to them, that of revolving, in the following manner: Have a flat swivel, made very exact, and tie on it two rockets obliquely, one on each side; which will make it turn the whole length of the line, and form a circle of fire. The charge for these rockets, should be a little weaker than that usually employed.
It is apparent, that a variety of figures may be put in motion, and consequently new appearances formed, by different contrivances. To represent, for instance, two fighting dragons, we must have two swivels, made square; and on each swivel, tie three rockets together, on the under side. Then having two flying dragons, made of tin, fix one of them on the top of each swivel, so as to stand upright, and in the mouth of each dragon, put a case of common fire; and another at the end of the tail. Two or three port-fires may also be put on the sides of their bodies to illuminate them Put them on the line, one at each end; but let there be a swivel in the middle of the line, to keep the figures from striking together. Before the rockets are fired, light the cases on the dragons, and, if care be taken in firing both at the same time, they will meet in the middle of the line. They will then turn, and run back with great violence. The line for these rockets, must be very long.
Sec. XI. Of Signal Sky-Rockets.
Signal rockets seldom exceed a pound in weight. Those which are employed in the land and sea service, are sometimes capped, or headed, and contain stars, serpents, &c. Two sorts of signals are used when artificial works are to be exhibited; namely, one with serpents, and the other without. Rockets which are to be bounced, must have their cases made one and a half or two diameters longer than the common proportion, and, after they are filled, a small quantity of clay is put in. Then bounce and pinch them in the usual manner, and fix on each a cap. Signal sky-rockets, without bouncers, are only sky-rockets closed and capped. These are very light, and, therefore, do not require such heavy sticks as those with loaded heads. Signal rockets, with reports, are fired in small flights; and are often, as well as those without reports, used for signals of the commencement of an exhibition of fire-works.
Signal rockets may be seen at a great distance, and observed instantly, when neither flags nor telegraphs could be observed without glasses; and may be so formed, as even to communicate particular orders or intelligence, by varying their decorations, their mode of ascension, as in the caduceus rocket, and by several other means.
VIII. OF SUNDRY FIRE-WORKS, DENOMINATED AIR-WORKS
Before we notice the various kinds of wheel-works, and their appendages, we purpose to consider the formation of gerbes, air-balloons, mortars, bombs, tourbillons, aigrettes, and some other works.
Sec. I. Of the Composition and Mode of forming large and small Gerbes.
In preparing cases for gerbes, it is necessary that they should be made strong; as they would be liable to burst, on account of the strength of the composition, which comes out with great velocity. They should be of the same thickness at top and bottom, and the paper well pasted. Their necks should be long, in which case, the iron would have more time to be heated, by meeting with more resistance in its disengagement, than if the neck was shorter; for then it would be burnt too wide before the charge was consumed. Long necks will throw the stars to a greater height, which will not fall before they are spent. They should rise and spread in such a manner as to resemble a wheat-sheaf.
Gerbes are generally made about six diameters long, from the bottom to the top of the neck. Their caliber must be one-fifth narrower at top than at bottom. Their neck is one-sixth diameter, and three-fourths long. There is a wooden foot or stand, on which the gerbe rests. This may be made with a choak or cylinder, four or five inches long, to fit the inside of the case, or with a hole in it to put in the gerbe: both these methods will answer the same end. In the charging of gerbes, there will be no need of a mould, the cases being sufficiently strong to support themselves. Before this operation is commenced, we must be provided with a piece of wood made to fit in the neck. If this precaution is not used, the composition will fall into the neck, and occasion a vacancy in the case, which will inevitably burst it, the moment the fire reaches the air. A weak composition should be put in at first, to the quantity of one or two ladles full. After the case is filled, take out the piece of wood, and fill the neck with slow charge.
Small gerbes, or white fountains, as they are sometimes called, are usually made of four, eight, or sixteen ounce cases, of any length, taking care to paste, and otherwise make them very strong. Before they are filled, however, drive in clay one diameter of their orifice high. When filled, bore a hole through the centre of the clay to the composition. The ordinary proportion will answer for the vent, which must be primed with a slow charge. Large gerbes are made by their diameters, and their cases at bottom one-fourth thick. The interior diameter of a gerbe is found, by supposing the exterior diameter of the case, when made, to be five inches, by taking two-fourths for the sides of the case, and there will remain two and a half inches for the bore.
Gerbes produce a brilliant fire, and appear remarkably beautiful, when a number of them are fixed in front of a building.
The composition of gerbes is similar to that of the Chinese fire. It is to the cast-iron, which enters into it, that its beautiful effects are to be ascribed. In fact, the composition of Chinese fire differs considerably, as we shall notice, when we treat of it, according to the purpose for which it is employed. It is adapted, for instance, in various proportions of its constituent parts, to calibers of different diameters, cascades, representation of palm trees, as well as for large and small gerbes. The old formula for gerbes is the following.
Composition for Gerbes.
Meal-powder, 6 lbs. Beat cast-iron, 2 lbs. 1½ oz.
The present formula, as we remarked when speaking of compositions for calibers from three-quarters of an inch to an inch, is saltpetre 1 oz, sulphur 1 oz, meal-powder 8 oz, charcoal 1 oz, and pulverized cast-iron 8 oz.
The vivid and rapid combustion which ensues, when this composition is inflamed, cannot be accounted for in any other way, than that the nitre is acted upon by the sulphur, the charcoal, and the iron; that the gunpowder, during its combustion, raises the temperature to the degree necessary for the decomposition of the nitre by the substances mentioned; that sulphurous and probably sulphuric acid, as well as carbonic acid, are generated, by the union of the sulphur and carbon with a part of the oxygen of the nitre; that the iron undergoes a combustion, both in contact with the nitre and with atmospheric air; and, lastly, that the effect, which characterizes this composition, and other similar compositions, into which cast-iron enters, as in the celebrated Chinese fire, is to be attributed to the iron; and the appearance which iron assumes, when in a state of combustion, is owing to no other cause than its rapid combination with oxygen, by which the metal is oxidized. (See Iron, in Part I.)
Sec. II. Of Paper Mortars.
It may not be improper, in this place, to give the manner of forming paper mortars. These mortars are necessary for a variety of exhibitions, as will appear hereafter.
Mortars are made of stout paper; or several sheets are pasted together, and made into pasteboard, in the manner before described. (See Pasteboard.) The preparations are various according to the size required. For a coehorn mortar, which is 4 inches and 2/5ths in diameter, roll the pasteboard on the former, on which it is made, 1/6th of its diameter thick, and, when dry, cut one end smooth and even; then nail and glue it on the upper part of the foot. Afterwards cut off the pasteboard at the top, allowing for the length of the mortar, two and a half diameters from the mouth of the powder chamber.
The mortar is then bound round with a strong cord, wetted with glue. The bottom of the foot, it being turned out of elm, is one diameter and two thirds broad, and one diameter high, and the part which goes into the mortar is two-thirds of its diameter in height. The copper chamber for the powder, which is separate from this, is made in a conical form, and is one-third of the diameter wide, and one and a half of its own diameter long. In the centre of the bottom of this chamber, make a small hole, a short distance down the foot; this hole must be met by another of the same size, made in the side of the foot. If these holes are made true, and a copper pipe fitted into both, the mortar, when loaded, will prime itself; for the powder will naturally fall to the bottom of the first hole. By putting a piece of quick match to the side, it will be prepared for firing.
When mortars of a larger size than ten inches in diameter are required, it is better to have them made of brass. See further observations on this subject in section seventh of this chapter, in the article on fire-pots.
Sec. III. Of Mortars to throw Aigrettes, &c.
Shells are filled with a variety of pyro-preparations, as stars, rains, serpents, &c. These are put in first, and then the blowing powder, as it is called; but the shells must not be quite filled. They must be introduced into the shells through the fuse hole. Some substances, however, as marrons, being too large to go through the fuse hole, must be put in before the shell is closed. When the shells are loaded, glue and drive in the fuses very tight. With respect to the diameter of the fuse hole; for a coehorn balloon, let the diameter be seven-eighths of an inch; for a balloon, five and a half inches in diameter, make the fuse hole one inch and one-sixth in diameter; for an eight-inch balloon, one inch and three-eighths; and for a ten-inch balloon, one inch and five-eighths.
Air-balloons are divided, according to the substances they contain, or the effect they are to produce, and are usually of four kinds; namely, 1. Illuminated air-balloons, 2. Balloons of serpents, 3. Balloons of reports, marrons, and crackers, 4. Compound balloons. Balloons and shells, in fire-works, are the same.
In the following view of the different balloons, we have given the number and quantity of each article for the different shells, designating their kind and character:
Coehorn balloon Illuminated.
Meal-powder, 1½ oz. Grain, do. ½ -- Powder for the mortar, 2 --
Length of the fuse composition, three-quarters of an inch: 1 oz. drove or rolled stars, as many as will nearly fill the shell.
Coehorn balloon of Serpents.
Meal-powder, 1½ oz. Grain, do. ½ -- Powder for the mortar, 2¼ --
Length of the fuse composition 13/16ths of an inch: half-ounce cases, driven three diameters, and bounced three diameters, and half-ounce cases, driven two diameters and bounced four diameters, of each, an equal quantity; and as many of them as will fit in easily, placed head to tail.
Coehorn balloons of Crackers and Reports.
Meal-powder, 1¼ oz. Grain, do. ¾ do. Powder for the mortar, 2 do.
Length of the fuse composition 3/4 of an inch; reports 4, and crackers of six bounces, as many as will fill the shell.
Compound Coehorn Balloons.
oz. dr. Meal-powder, 1 4 Corn, do. 0 12 Powder for the mortar, 2 4
Length of the fuse composition 13/16ths of an inch: 1/2 oz. cases driven 3-1/2 diameters, and bounced 2, 16; 1/2 ounce cases driven 4 diameters and not bounced, 10; rolled stars, as many as will complete the balloon.
Balloons illuminated (Republican).
oz. dr. Meal-powder, 1 8 Grain, do. 0 12 Powder for the mortar, 3 0
Length of the fuse composition 15/16ths of an inch; 2 oz. strung stars, 34; rolled stars, as many as the shell will contain, allowing for the length of the fuse.
Balloon for Serpents, (Republican).
oz. dr. Meal-powder, 1 Grain, do. 1 8 Powder for the mortar, 3 8
Length of the fuse composition, 1 inch; 1 oz. cases driven 3-1/2 and 4 diameters, and bounced 2, of each an equal quantity, sufficient to load the shell.
Balloons with crackers and Marrons. (Rep.)
oz. dr. Meal-powder, 1 8 Corn powder, 1 4 Powder for the mortar, 3
Length of the fuse composition 14/16ths of an inch; reports 12; to be completed with crackers of 8 bounces.
Compound balloons (Republican).
oz. dr. Meal-powder, 1 5 Corn powder, 1 6 Powder for the mortar, 3 12
Length of the fuse composition, one-inch; 1/2 ounce cases driven and bounced 2 diameters, 8; 2 oz. cases filled 3/8ths of an inch with star-composition, and bounced 2 diameters, 8; silver rain falls, ten; 2 oz. tailed stars, 16; rolled brilliant stars, 30. If this should not be sufficient to load the shell, it may be completed with gold rain falls.
Eight-inch balloons Illuminated.
oz. dr. Meal-powder, 2 8 Grain powder, 1 4 Powder for the mortar, 9
Length of the fuse composition, one inch and 1/8th; 2 oz. drove stars, 48; 2 oz. cases, driven with star composition, 3/8ths of an inch, and bounced 3 diameters, 12; and the balloon completed with 2 oz. drove brilliant stars.
Eight-inch Balloons of Serpents.
oz. dr. Meal-powder, 2 0 Corn powder, 2 0 Powder for the mortar, 9 8
Length of the fuse composition, 1 inch and 3/16ths; 2 oz. cases driven one and a half diameters, and bounced 2, and one-ounce cases driven 2 diameters, and bounced 2-1/2; of each an equal quantity, sufficient for the shell.
We may remark, that the star composition, driven in bounced cases, must be managed in the following manner: First, the cases must be pinched close at one end, then the corn-powder put in for a report, and the case pinched again close to the powder, only leaving a small vent for the star-composition, which is driven at top, to communicate to the powder at the bounce end.
Compound eight-inch Balloon.
oz. dr. Meal-powder, 2 8 Corn powder, 1 12 Powder for the mortar, 9 4
Length of the fuse composition, 1/8th of an inch; 4 oz. cases, driven with star composition, 3/8th of an inch, and bounced 3 diameters, 16; 2 oz. tailed stars, 16; 2 oz. drove brilliant stars, 12; silver rain falls, 20; 1 oz. drove blue stars 20; and 1 oz. cases driven and bounced, two diameters, as many as will fill the shell.
Another of eight-inches.
oz. dr. Meal-powder, 2 8 Corn, do. 1 12 Powder for the mortar, 9 4
Length of the fuse composition, 1 inch and 1/8th; crackers of six reports, 10; gold rains, 14; 2 oz. cases driven with star composition, 3/16ths of an inch, and bounced 2 diameters, 16; 2 oz. tailed stars, 16; 2 oz. drove brilliant stars, 12; silver rains, 10; 1 oz. drove blue stars, 20; and 1 ounce cases, driven with brilliant charge, 2 diameters, and bounced 3, as many as the shell will hold.
A compound ten-inch Balloon.
oz. dr. Meal-powder, 3 4 Corn powder, 2 8 Powder for the mortar, 12 8
Length of the fuse composition 15/16ths of an inch; 1 oz. cases driven and bounced 3 diameters, 16; crackers of eight reports, 12; 4 oz. cases, driven 1/2 an inch with star composition, and bounced 2 diameters, 14; 2 oz. cases driven with brilliant fire 1 and 1/4th diameters, and bounced 2 diameters, 16; 2 oz. drove brilliant stars, 30; 2 oz. drove blue stars, 3; gold rains, 20; silver rains 20. After all these are put in, fill the remainder of the case with tailed and rolled stars.
Ten inch balloons of three charges.
oz. dr. Meal-powder, 3 0 Corn-powder, 3 2 Powder for the mortar, 13 0
Length of the fuse composition, 1 inch: the shell must be loaded with 2 oz. cases, driven with star composition 1/4th of an inch, and on that one diameter of gold-fire, then bounced three diameters; or with 2 oz. cases, first filled one diameter with gold fire, then one and one-fourth diameters of brilliant fire. These cases must be well secured at top of the charge, lest they should take fire at both ends: but their necks must be larger than the common proportion. For the manner of forming balloon cases of paper, consult the article on that subject, in a preceding chapter.
Balloons, the bombs of some, may be formed of different sizes, and made proportionably strong.
Bombs may be formed of wood by turning it round, and hollow, of a sufficient thickness, and in two parts, which fit each other like a common snuff box. The inferior or lower part must be made thicker than the upper, as it rests upon the powder; and for the same reason, that iron bombs are cast thicker at their bottom. One-twelfth of the diameter is considered a sufficient thickness for the under part, and one-fifteenth for the upper part, which is pierced with a hole to receive the fuse. This hole is called the eye of the bomb.
When balloons, or bombs, are to be charged, the decorations may be varied in the same manner as for sky-rockets. Stars, golden rain, and meteors, are considered the best, as they produce the most brilliant effect.
After the addition of the furniture or decorations, we finish the charge by putting in coarse grain powder, which is introduced through the eye. The fuse is then driven in. It is glued, in order to secure it. The bomb is now covered with three or four turns of canvass, and over this some paper, to secure it. In this state, it ought not to be more than 1/11th of an inch smaller than the caliber of the mortar. This leaves what is denominated the windage.
When the bombs are well dried, the fuse is primed with a double match, and priming paste. A cup, made with two turns of paper, is then attached to the fuse, which receives the double match.
The bomb, thus prepared, is then placed in a cone made of pasteboard, which contains the powder of the charge, or that required for its ascension, and is put into the mortar. One of the matches above described, communicates the fire to the fuse, and the other at the same time to the powder in the cone. The match, it is to be observed, comes out of the mouth of the mortar, and serves to fire it. This mode of discharging the mortar, differs from the one we have previously given.
The following table exhibits the calibers for bombs, the length of the fuse for each caliber, and the weight of the powder required for the charge.
Caliber for bombs. | Length of the fuse. | Weight of the charge. ---------------------+---------------------+---------------------- Bombs of 4 in. diam. | 1¼ inches. | 2 oz. cannon powder. ---- 6 do. -- | 1⅔ do. | 5 oz. do. ---- do. ---- 9 do. -- | 2 do. | 6 oz. do. ---- do. ---- 12 do. -- | 2 do. | 9 oz. do. ---- do.
Having made some remarks respecting bombs, we will now offer a few observations concerning mortars; and although we have, on a former occasion, mentioned something respecting them, yet we deem a few remarks on this head not improper at this time.
Mortars, from five to six inches bore, are usually made of pasteboard and canvass. The canvass is first soaked in a gelato-amylaceous paste, or paste composed of half glue and half flour; and, when put on, is covered with sheets of pasteboard, which are glued or pasted. For various kinds of paste, see Pasteboard.
When the case, or mortar is to be formed, cylinders of wood as formers are employed. They are of different diameters, according to the size of the mortars, that are to be made. For four-inch mortars, inch formers; for six-inch, one and a half inch formers, &c. After they are rolled and pasted on the former, they are dried on it. As to their strength, this depends on the thickness of the case. A mortar of four inches in interior diameter, ought to be six inches in exterior diameter, and those of six in interior, should be nine, exterior. The cases being formed, we next have turned as many cylinders of walnut, as cases or pots. These cylinders are short. In each is formed a conical chamber, in the shape of the letter V, which is afterwards lined with tin or brass, to prevent the action of the powder. They are then glued and put into the end of each pot, about the length of an inch, and further secured by nails.
The chamber is designed to receive the powder, and its conical form enables it to act with all its force immediately on the bomb. A flat bottom would not have this advantage, as the powder in that case would have more room, and consequently its force be divided. They are sometimes, however, made flat.
The charge for these mortars, as a general rule, is 1/30th part of the weight of the bomb.
When mortars are to be larger than the sizes we have mentioned, it is necessary to have them of metal, and for this purpose copper is generally employed. Its thickness should be one-fourth of an inch, for a nine-inch mortar; and half an inch, for twelve-inch mortars. A cone of copper is to be made in the same way as above mentioned. This is secured, and made solid by means of lead.
In experiments and exhibitions, the powder, we may observe, must be of the same strength.
We find then, that mortars, for the discharge of bombs, or balloons, are differently made from those which are used for throwing iron-shells. In fire-works, the design of mortars is to project the balloon in a vertical direction, which, being furnished with a fuse as in ordinary shells, receives the fire from the gun-powder; and at a given time, according to the length of the fuse, the fire is communicated to the balloon, which bursts and scatters its contents in the atmosphere. The furniture for balloons being various, and in a larger quantity than could be contained in the heads of rockets, (except the Congreve,) the appearance is more grand and impressive. It is obvious, that, when they burst, fire is communicated to the whole at the same time; and the quantity of powder is usually sufficient, not only to burst the shell, but also to throw the contents to some distance. The height, to which balloons ascend, depends, of course, on the quantity of gunpowder put in the mortar. The quantity is generally regulated.
We find, also, that two modes are used for discharging the mortars. The one consists in having a communication from without to the bottom of the cone, which contains the powder, and applying the match to this vent, on the same principle as that for firing a cannon, or common mortar. The other, by firing a quick-match in the conical cavity, and putting in the charge with the balloon; letting the match, however, be of a sufficient length to come out of the mouth of the mortar, and fall over its side. This match, when fired, will communicate fire to the powder in the cone, and produce the same effect. Metallic cylinders, and especially copper, however small, are certainly preferable to those made in the usual manner.
Sec. IV. Of making Balloon Fuses.
Wood, particularly beech, is generally employed for forming fuses, which is turned of the shape required. If made with pasted paper, they will answer for the purpose of fire-works. The diameter of the former for fuses for coehorn balloons must be half an inch; for a republican fuse, five-eighths of an inch; for an eight-inch fuse, three-fourths of an inch; and for a ten inch fuse, seven-eighths of an inch. Having rolled the cases, pinch and tie them almost close at one end; then drive them down, and let them dry. Before they are filled, mark on the outside of the case, the length of the charge required, allowing for the thickness of the bottom; and when the composition is rammed in, take two pieces of quick-match about six inches long, and lay one end of each on the charge, and then a little meal-powder, which is to be rammed down loose. The loose ends of the match, double up, and place in the top of the fuse. This top must be covered with a proper cap to keep it dry. When the shells are put into the mortars, uncap the fuses, and pull out the loose ends of the match, and let them hang on the sides of the balloon. The use of the match is to receive the fire from the powder in the chamber of the mortar, in order to light the fuse. When the shell is put in the mortar, its fuse must be uppermost, and exactly in the centre. Some meal-powder is usually sprinkled upon it.
Fuses of wood are longer than those of paper, and not bored through, but left solid about 1/2 an inch at bottom; so that, when used, this end is cut off. They are sawed, however, at a proper length, measuring the charge from the cup at top. On the subject of Fuses, see the last part of the work.
Fuses for bombs, Morel remarks, are formed of five thicknesses of paper, or of pasteboard, made of that thickness; and the former, on which the fuse case is rolled, should be one-third diameter. The composition is put in with a spoon, and each charge is driven with twenty strokes of a moderate size mallet.
Composition for the fuses of bombs or balloons.
1. Meal powder, 12 oz. Sulphur, 4 -- Charcoal, 6 --
2. Saltpetre, 1 lb. 10 -- Sulphur, 8 -- Meal powder, 1 lb. 6 --
3. Saltpetre, 1 lb. 8 -- Sulphur, 8 -- Meal powder, 1 lb. 8 --
Sec. V. Of the Mosaic and Common Tourbillon.
The tourbillon de feu of the French, or whirlwind of fire, is the same as the soleil montant; because it ascends in full illumination, and scatters fire in various directions. The tourbillon, therefore, receives its name from the effect it produces. It raises itself very high, and forms a whirl of fire and terminates in two coronal figures, or crowns, which descend in what are called parasols. It does not, however, produce crowns, except when it is charged with Chinese fire.
There are two kinds of tourbillons, which we will describe, namely, the mosaic and the common. The mosaic produces a tail of some length, and after whirling round, finishes with a report. This effect is owing to its particular structure and formation, as it differs from the common tourbillon. In preparing the cases for mosaic tourbillons, pasteboard, formed of five sheets of paper, is used. They are made seven inches in length upon a roller or former 5/12ths of an inch in diameter. Their thickness, when rolled, is 1/8th of an inch. They are choaked in the usual manner, and the excess of the string is cut off. After having put a quarter of an inch of earth into a case, and beating it with ten or twelve blows with the mallet, we mark the height of the earth on the outside of the case. We then load it to the height of 7/12ths with the composition heretofore mentioned. Another quarter of a spoonful of earth is then put in. We then choak, and bind the case in this place. Two fingers of grain powder are now added; we again choak, and bind it above this. We put in the same composition, after the last operation, to the height of 7/12ths of an inch. The choaking, it is to be observed, must not wholly close the case; so that the composition can set fire to the powder.
We now introduce a spoonful of earth, and choak and bind as before. It is then finished by charging it with 7/12ths of an inch of composition. The remainder of the case is cut, and the composition primed.
Cases, thus prepared, are afterwards treated in the following manner: We pierce three holes in the sides of each, one a little above the last choak, another through, or into the case, to penetrate the last charge, and the third through the first charge. These holes have a communication with each other by means of quickmatch; so that, when the match is set on fire, the two extremes are inflamed at the same time, and being opposed to each other, give a rotary motion to the tourbillon, which, when the powder inflames, terminates by an explosion. The holes ought to be covered with three or four turns of pasted paper. It is then ready to be put into the pots de chasse. When completed, the tourbillon should not exceed 10/12ths of an inch in diameter.
The pots de chasse (mortars somewhat similar to those described) should be made of pasteboard, prepared with eight thicknesses of paper, and moulded upon a roller of 11/12ths of an inch in diameter. They are mounted in the same manner as fire-pots, and are also primed in the same way.
Into each pot there is put four drachms of broken grain powder, and a slip of pasteboard, pierced with five or six holes, which is introduced by means of a stick. A little meal-powder is then put into the pot, and afterwards the tourbillon, the primed end of which must be above the chasse. It is then closed with paper, made into a wad or ball, and the pot is secured with a slip of pasteboard, pasted on it.
Composition of Mosaic Tourbillons.
1. Meal powder, 16 oz. Charcoal, 3 or 4 dr.
2. Meal powder, 16 parts. Charcoal, 3⅓ ----
Common tourbillons differ in many respects from the mosaic, although their motion is the same. There are two methods of forming them as well as their appendages, both of which we purpose to describe. The first is the following: Having filled some cases within about 1-1/2 diameters, drive in a handful of clay, prepared, of course, in the manner described in the first part of the work; then pinch their ends close, and drive them down with a mallet. Then find the centre of gravity of each case; where you nail and tie a stick, which should be 1/2 an inch broad at the middle, and run a little narrower to the ends; these sticks must have their ends turned upwards, so that the cases may turn horizontally on their centres. At the opposite sides of the cases, at each end, bore a hole close to the clay, with a gimblet the size of the neck of a common case of the same nature. From these holes, draw a line round the case, and, at the under part of the case, bore a hole with the same gimblet, within half a diameter of each line, towards the centre; then from one hole to the other, draw a right line. This line divide into three equal parts, and bore a hole near to each of the ends; then from these holes to the other two, lead a quick-match, over which paste a thin paper.
It is to be observed, that there is a stick about the length of the case, which goes across it, and is securely fastened by a cord, that the whole lies flat upon a table before it is fired, and hence, it is sometimes named the table tourbillon; and, that the leader should be carried from one side hole to the other, the holes being made at the opposite sides, as before mentioned. When tourbillons are fired, they must lay upon a smooth table, with their sticks downwards, the leader being set on fire in the middle with a port fire. They should spin two, three, or four seconds round the table, before they rise, which is about the time the composition will be burning from the side holes to those at the bottom.
Reports, or detonating cases, may be fixed to tourbillons, if so required. In this case, we make a small hole in the centre of the case at top, and in the middle of the report make another. Then place them together, and tie on the report, and, with a single paper, secure it from fire. By this method, small cases of stars, rains, &c. may be fixed on tourbillons, being careful, nevertheless, that they are not overloaded.
One-eighth will be a sufficient thickness for the sticks, and their length equal to that of the cases.
The other mode of forming common tourbillons, is the following: They are made with cases of an inch, which are choaked and bound in the usual manner. In filling, we make two wads of paper of the same size, and put one of them into the case, and ram it with fifteen or twenty blows. We then mark upon the case, the height of this wad, which is afterwards driven with the composition, given at the end of this section. To each charge, thirty strokes of a moderate size mallet, will be required; and each charge should not be more in height in the case than nine exterior diameters. We mark, on the outside of the case, the height of this charge, and put in a wad of the same kind and size as the former one. We drive this in the same manner as the first, and then choak and bind the case. After cutting off the excess of the ligature, with which we bound the case, we again introduce the rammer, and give it eighteen blows with the mallet, in order to flatten the choak.
We afterwards divide the case parallel to each end, into four equal parts, and mark the height of the wads. That of the middle, which becomes in fact the bottom of the case, (from the manner it is fixed for ascension), we divide into five equal parts from one point to the other, and pierce a hole in each division to the composition. We then make, on a level with the wads, upon the lateral lines, two similar holes; one upon one side, and the other on the other side, at the opposite ends. These holes are so made as that the case has four holes on one line, and one upon each of the other two. Each hole is then primed with a piece of quick match, and priming paste. One of these matches must pass over all the other holes; so that the fire may be communicated from one to the other at the same time. The matches are then covered with a band of pasted paper. To hold the tourbillon in a horizontal position, we procure a hoop of the same thickness and diameter as the length of the case; and on the plate, we make a groove for the match of communication, which is supported between the four holes with an iron wire. If the case whirls round with a uniform motion, it is well balanced.
The four holes beneath, serve to raise it in the air, and the two lateral apertures give it a revolving motion.
When tourbillons are to be set off, they must be balanced either by a cross stick, as in the first instance, or some other contrivance. The effect is the same as before described.
Composition for Tourbillons, or Table Fusées, of different Calibers.
-------------+----------------+-------------------+------------------ Substances. |Calibers of ⅓d |Of ⅔ds of an inch |Of ⅚ths of an inch | of an inch. |with Chinese fire. | with Chinese fire. -------------+----------------+-------------------+------------------ Saltpetre, | 8 oz. | 16 oz. | 16 oz. Sulphur, | 4 oz. | 8 oz. | 8 oz. Meal-powder, | 16 oz. | 18 oz. | 16 oz. Charcoal, | 1 oz. | | Pulverized | | | cast iron, | | 10 oz. | 12 oz.
Another composition for a caliber of half an inch, of common fire.
Saltpetre, 16 oz. Sulphur, 4 -- Meal-powder, 7 -- Charcoal, 4 --
The following formulæ are sometimes used;
For four-ounce tourbillons.
Meal-powder, 2 lbs. 4 oz. Charcoal, -- 4½ --
For eight-ounce tourbillons.
Meal powder, 2 lbs. Charcoal, 4¾ oz.
For large tourbillons.
Meal-powder, 2 lbs. Saltpetre, 1 do. Sulphur, 8 oz. Beat-iron, 8 oz.
As a general rule, we may remark, that the larger tourbillons are made, employing, if necessary, different coloured fires, the weaker must be the charge; and, on the contrary, the smaller, the stronger their charge.
Sec. VI. Of Mortars for throwing Aigrettes, and the manner of loading and firing them.
Pots of aigrette, when inflamed, exhibit the appearance of an aigrette, or cluster of rays, such as are produced by diamonds, when they are arranged in a particular way. The aigrette takes its name from a bird, whose feathers serve to make up an ornament for the head. It was given in diamonds, as a particular mark of distinction, by the Grand Signior, to Lord Nelson, after the battle of the Nile. There are aigrettes made of glass.
For the purpose of throwing aigrettes, the mortars are generally made of pasteboard, of the same thickness as balloon mortars, and two and a half diameters long in the inside from the top of the foot. The latter must be made of elm without a chamber, but flat at top, in the same proportion as those for balloon mortars. These mortars must be bound round with a cord as before mentioned. Sometimes eight or nine of these mortars, of about three or four inches in diameter, are bound altogether, so as to appear as one; but when they are prepared for this purpose, the bottom of the foot must be of the same diameter as the mortars, and only one-half a diameter high. Having bound the mortars together, fix them on a heavy solid block of wood. To load them, place over the inside bottom of each, a piece of paper, and spread on it one and a half ounces of meal and grain powder mixed; then tie the serpents up in parcels with quickmatch, and put them in with their mouths downwards. Care must be taken, that the parcels do not fit too tight in the mortars, and that all the serpents have been well primed, or wetted with the paste of meal powder and spirit of wine.
On the top of the serpents, in each mortar, lay some paper or tow; then carry a leader from one mortar to the other, and from all the outside mortars to that in the middle. These leaders are to be put between the cases and the sides of the mortar, down to the powder at bottom. In the centre of the middle mortar, fix a fire pump, or brilliant fountain, and sufficiently long to project out of the mouth of the mortar. Then secure the mortars, by pasting paper over their tops.
The nest of serpents (as mortars thus prepared are called) is fired by lighting the fire-pump, which, when consumed, will communicate to all the mortars at once by means of the leaders.
Single mortars are called pots des aigrettes. If the mortars, when loaded, are sent to any distance, or liable to be much moved, the firing powder should be secured from getting amongst the serpents, which would endanger the mortars, as well as injure their performance. To prevent this accident, the mortars are to be loaded in the following manner; First, put in the firing powder, and spread it equally; then cut a round piece of blue touch paper, equal to the exterior diameter of the mortar, and draw a circle on it equal to its interior diameter, and notch it as far as that circle: then paste that part, which is notched, and put it in the mortar close to the powder, and stick the pasted edge to the mortar. This will secure the powder at the bottom, so that it may be moved and carried without receiving any damage.
For mortars of six, eight, or ten inches diameter, the serpents should be made in one and two-ounce cases, six or seven inches long, and fired by a leader, brought out of the mouth of the mortar, and turned down the outside; its end being covered with paper, to prevent the sparks of the other works from setting it on fire. For a six-inch mortar, let the quantity of powder for firing be two ounces; for an eight-inch, two ounces and three-quarters; and for a ten-inch, three ounces and three-quarters. Care must be taken in these, as well as small mortars, not to put the serpents in tight, for fear of bursting the mortars. These mortars may be loaded with stars, crackers, &c.
Sec. VII. Of Making, Loading, and Firing Pots des Brins.
These are formed of pasteboard, and must be rolled pretty thick. They are usually made three or four inches in diameter, and four diameters long; and pinched at one end like common cases. A number of these are placed on a plank in the following manner: Having fixed on a plank two rows of wooden pegs, cut, in the bottom of the plank, a groove the whole length, under each row of pegs. Then through the centre of each peg, bore a hole down to the groove at bottom, and, on every peg, fix and glue a pot, whose mouth must fit tight on the peg. Through all the holes, run a quick-match, one end of which must go into the pot, and the other into the groove, having a match laid in the groove from end to end, and covered with paper; so that, when lighted at one end, it may discharge the whole almost at the same instant. In all the pots, put about one ounce of meal and grained powder. Then in some put stars, and in others rains, snakes, serpents, crackers, &c. When they are all loaded, paste paper over their mouths. Two or three hundred of these pots being fired together, make a brilliant appearance by affording so great a variety of fires.
Sec. VIII. Remarks respecting Fire Pots.
Fire pots, called also pots of ordnance, in pyrotechny, are nothing more than vessels used in, as well as for, the exhibition of artificial fire-works. They are generally formed of thick pasteboard, made by pasting together six or eight sheets of paper, of two inches interior diameter, three inches exterior diameter, and fifteen inches long. They are always placed upon a solid block or plank, and preserved in a firm position. There is a stopper or plug made of wood, which goes one inch into each case or pot, and is there glued and secured by nails. This plug is turned with a screw, which enters the plank, and preserves the pot in a steady position. The plank, on which the pots rest, is usually three inches wide, an inch and a half thick, and sufficiently long to receive twelve pots, placed at the distance of half an inch apart. Before the pots are fixed on, a hole is made through each plug in its centre, to receive a quick match, which passes through to the composition. A groove is also made in the plank, in its length, one-third of an inch square; and in such a manner, that the holes, which communicate to the interior of the pots through the plugs, must come in the middle of the groove. When the quick-match is put through the plugs, to communicate with the interior of the pots, we must leave about two inches on the outside. At each hole, also, we put some priming paste, and then permit it to dry.
If it is required to discharge them all at once, this may be done by making a communication through the groove, by means of leaders in the manner before mentioned; and covering the leaders with four or five bands of paper, and setting the match or leader on fire. If, on the contrary, they are to go off in succession, the groove is filled with bran, which is pressed with the fingers, and is then covered with paper. The match of communication with the pots must, however, be preserved. The bran causes the fire to communicate gradually from one to the other.
Pots are charged in the following manner: We first make the sacs of powder. For this purpose, we have as many squares of paper as there are pots, which are made into cylinders on the same roller that formed the pots. Into each is put about an ounce of the charge-composition, hereafter mentioned, with two pieces of match, sufficiently long to come out an inch. They are then closed and tied, and the excess is cut off. One of these sacs is put into each pot, having previously pierced it with several small holes, and sprinkled it with meal powder. After this, the garnishing, furniture, or decoration is added, always observing to put the primed part downwards. A wad of paper is then put over the whole, and the mouth is closed with pasted paper.
Composition of the charge for fire pots.
Gunpowder, in broken grains, 16 oz. Charcoal, 3 --
Fire pots are discharged in the way we have described, which is considered the best and most certain; or they may be fired by communicating the fire with a match, passing out of the mouth, and hanging over the sides. Another mode may be used, similar to that for discharging balloons or bombs, but on a scale proportionate thereto. Pots may be discharged in any direction; hence two pieces, or sets, may be fired adversely, like rockets from the regulated rocket case. Their effect depends, as we have frequently observed, on their furniture or decorations.
The strength of fire pots is also to be considered. If they are made three inches in interior diameter, it is prudent to cover them with stout canvass, or small cord, wrapped round and covered with a coat of glue, in the same manner as for tourbillons.
Fire pots are calculated to throw serpents, &c. in the air. Mortars, it will be recollected, are designed to discharge shells or balloons, which are thrown to a considerable height, by the powder placed in the conical cavity; whereas fire pots, although their contents are thrown out by blowing powder, are differently made at the bottom, and merely designed to project serpents, stars, &c. to a small distance. Being primed, they take fire as they pass out of the pot. The charge is sometimes gunpowder, and, as above, composed of gunpowder and charcoal, to lessen the power of the former. The principle, on which they are discharged, is the same. Fire pots are called pots of ordnance, because they are used for discharging sundry substances, by means of gunpowder.
IX. OF PARTICULAR COMPOSITIONS
Sec. I. Of Fire-Jets, or Fire-Spouts.
Fire-jets are produced by certain compositions, which are employed in cases, and are charged solid. They are formed and used according to taste or fancy.
The jets are made with a caliber of from one-third of an inch, to one inch and one-third, in interior diameter. They are seven or eight exterior diameters in length, and are charged in the usual manner with the composition, hereafter mentioned, driving each charge with twenty blows with a small mallet. The first charge must be the common fire composition.
Some of the compositions in the following table have already been mentioned, when treating of certain fire-works; but we deem it of importance to notice them in a connected manner, so that we may have the formulæ in one view.
Fire-jets, it must be remembered, are calculated as well for turning, as for fixed pieces.
Common Fire for calibers of one-third of an inch.
Meal-powder, 16 oz. Charcoal, 3 --
Common Fire for calibers of five-twelfths to half an inch.
Meal-powder, 16 oz. Charcoal, 3 -- 4 dr.
Common fire for calibers above half an inch.
Meal-powder, 16 oz. Charcoal, 4 --
Brilliant fire for ordinary calibers.
Meal-powder, 16 oz. Filings of iron, 4 --
Another, more beautiful.
Meal powder, 16 oz. Filings of steel, 4 --
Another, more brilliant, for any caliber.
Meal powder, 18 oz. Saltpetre, 2 -- Filings of steel, 5 --
Another, very brilliant, for two-thirds of an inch caliber, and above.
Meal powder, 16 oz. Saltpetre, 1 -- Sulphur, 1 -- Filings of steel, 7 --
Brilliant fire, more clear, for any caliber.
Meal powder, 16 oz. Filings of needles, or of needle steel, 3 --
Silver-rain for calibers above two-thirds of an inch.
Meal powder, 16 oz. Saltpetre, 1 -- Sulphur, 1 -- Filings of steel, fine, 4 -- 4 dr.
Grand jessamine, for any caliber.
Meal powder, 16 oz. Saltpetre 1 -- Sulphur, 1 -- Filings of spring steel, 6 --
Small jessamine, idem.
Meal powder, 16 oz. Saltpetre, 1 -- Sulphur, 1 -- Filings of steel, the best, 5 --
White fire, idem.
Meal powder, 16 oz. Saltpetre, 8 -- Sulphur, 2 --
White fire, idem.
Meal powder, 16 oz. Sulphur, 3 --
Blue fire, for parasols and cascades.
Meal powder, 8 oz. Saltpetre, 4 -- Sulphur, 6 -- Zinc, 6 --
Another blue fire, for calibers of half an inch, and upwards.
Saltpetre, 8 oz. Meal powder, 4 -- Sulphur, 4 -- Zinc, 17 --
The cases charged with this composition are only employed for furnishing the centre of some pieces, the movement of which depends on other cases; for these, having no force, would not move the piece.
Blue Fire, for any caliber.
Meal powder, 16 oz. Saltpetre, 2 -- Sulphur, 8 --
Radiant Fire, idem.
Meal powder, 16 oz. Filings of pins, (d'epingles) 3 --
Green Fire, idem.
Meal powder, 16 oz. Filings of copper, 3 -- 2 dr.
Aurora Fire, idem.
Meal powder, 16 oz. Gold powder, (Poudre d'or) 3 --
For Italian roses or fixed stars.
Meal powder, 2 oz. Saltpetre, 4 -- Sulphur, 1 --
Another, for the same.
Meal-powder, 12 oz. Saltpetre, 16 -- Sulphur, 10 -- Antimony, 1 --
The jets of fire, which are various according to the composition employed, may appear under several forms, sometimes in one and sometimes in another; and hence they may put on an asteroid appearance, or that of a fountain, or water spout, or the form of rain. The effect, however, is very elegant; and, in conjunction with other species of fire-works, cannot fail to change the general appearance, by modifying the whole, or rendering it more various.
These compositions are generally used in the manner before mentioned, in cases of different sizes; but they may, under particular circumstances, be employed otherwise. In fact, the forms which may be given to the flame of gunpowder, or the substances which compose it, either by increasing or retarding its combustion, or changing the appearance of the flame, and giving it the form of jets, stars, rain, &c. are so numerous, that it furnishes alone an important branch of Pyrotechny. These effects will be detailed, when we treat of the formation of compound works.
_Sec. II. Of Priming and Whitening Cases, and Remarks concerning Spunk and Touch Paper._
When the cases are charged, we pierce them with a small awl, or make a hole with a gimblet in the end, if it should be stopped with clay, or probe them with a drill, as fire-workers call it, in the hole which had been filled, in which we put some more of the composition. This precaution is considered necessary, in order that the earth should not cover internally the hole of the piercer. A piece of match is then introduced, which extends on the outside, and is secured there with a plug of wood.
Brown paper, made either of linen or cotton, but not of woollen cloth, when soaked in a concentrated solution of saltpetre, is, we have said, rendered very combustible, and will convey fire for small works with much facility. It is this paper, called touch, or more properly match, paper, that is used for capping, &c. Paper of this kind may sometimes be used, as for crackers, serpents, &c. Cotton quick-match, however, is used more generally; and, for large works, when employed as a leader, it is usually confined in a proper tube, the better to preserve it entire, and to keep it dry. Spunk, made by soaking certain species of fungus in a solution of saltpetre, takes fire very readily by the least spark, and, therefore, is used for collecting and preserving the fire from flint and steel. This spunk, when well made, and particularly of the proper kind of fungus, may be cut into slips, and employed advantageously in some fire-works. In all cases, however, the object is the same, to communicate fire with facility to the powder, or composition; and this object may be attained by all those methods, which we have had occasion frequently to mention. See Pyrotechnical Sponge.
To whiten cases is an operation, which merely consists in covering them with paper, and is performed in the following manner. We procure as many half-sheets of paper as we have cases, and put them on a table one upon another. We paste the paper, and roll each case in one of these sheets, which is named the covering. The paper is cut in such a manner, that it passes over the end of each case an inch and a half. There is no particular use in this covering, the case being made sufficiently strong without it; it makes, however, a handsome finish. In the Chinese fire-works, their cases are covered with different coloured papers, and frequently ornamented with gilding. In all that I have seen, with some of which I have made experiments, the match of communication is nothing more than twisted match-paper. The figures are made of paper, painted, and ornamented in the same way; some resembling animals, &c. but on a small scale. The leaders are fixed in the usual manner, and the works are fired in the same way. Tourbillons, serpents, and crackers are chiefly the kind which we have seen.
Sec. III. Of Chinese Fire.
The composition for producing this fire, as it is peculiar, and therefore distinct from all others, was invented by the Chinese, and hence bears that name. The substance, which produces the peculiar effect is cast or crude iron. See Iron.
It was the brilliant light, produced when iron filings are thrown into the fire, that gave rise to an improvement in the fire of rockets, rendering it much more beautiful, than when gunpowder, or the substances of which it is composed, are alone employed. The Chinese have long been in possession of a method of rendering fire brilliant, and variegated in its colours. Cast-iron, reduced to a powder more or less fine, is called iron-sand, because it answers to the name given to it by the Chinese. They use old iron pots, which they pulverize, till the grains are not larger than radish seed; and these they separate into sizes or numbers, for particular purposes.
It should be observed, that rockets, into the composition of which, iron-filings and iron-sand enter, cannot be long preserved, owing to the change which the iron undergoes in consequence of moisture.
It may be proper to introduce here two tables, which exhibit the proportions of the different ingredients for rockets of this kind from 12 to 33 lbs.
For Red Chinese Fire.
-----------+------------+----------+-----------+------------------ Calibers. | Saltpetre. | Sulphur. | Charcoal. | Pulv. cast iron. | | | | No. 1. -----------+------------+----------+-----------+------------------ lbs. | lbs. | oz. | oz. | oz. dr. 12 to 15 | 1 | 3 | 4 | 7 0 18 -- 21 | 1 | 3 | 5 | 7 8 24 -- 36 | 1 | 4 | 6 | 8 0 -----------+------------+----------+-----------+------------------
For White Chinese Fire.
-----------+------------+--------------+-----------+----------------- Calibers. | Saltpetre. | Meal-powder. | Charcoal. | Pulv. cast iron. | | | | No. 2. -----------+------------+--------------+-----------+----------------- lbs. | lbs. | oz. | oz. dr. | oz. dr. 12 to 15 | 1 | 12 | 7 8 | 11 0 18 -- 21 | 1 | 11 | 8 0 | 11 8 24 -- 36 | 1 | 11 | 8 8 | 12 0 -----------+------------+--------------+-----------+-----------------
These substances are incorporated together in the manner already stated.
The cast-iron, we observed, is reduced to a fine powder, or rather sand, as the French fire-workers call it, and is then passed through a sieve. For the method of reducing it to powder, consult the article on Iron. That the brilliancy of the fire is owing to the iron in its crude state, without being converted into soft or malleable iron, a process which carries off a large quantity of carbon, oxygen, &c. and increases its specific gravity,--is very evident from the effect produced. Wrought iron will occasion scintillations, somewhat of the same appearance, and steel, also, in greater abundance; and hence both are employed in sundry compositions. But the particular character, beauty, and brilliancy of Chinese fire must be attributed, first to the iron, and secondly to its peculiar state of combination with carbon and oxygen; for, we have said, that malleable iron, (which is deprived in a great measure of these substances in the operation required for its preparation), produces an effect far inferior to cast iron. This difference then can only arise from the quality, character, composition, or properties of these two kinds of iron. Steel, on the contrary, having a more vivid effect than wrought iron, owes its properties to another state of combination of the iron and carbon.
Hence we account for the difference in the appearance of the flame, and consequently the effect, in the different mixtures of crude iron, malleable iron, and steel. We have already remarked, in treating of iron, and in explaining the action of bodies in the process of combustion, in the section on the theory of fire-works, that the effect of some substances was to produce sparks, stars, &c. In the present instance, namely, the effect of the composition of the Chinese fire by combustion, the iron is first ignited by the powerful heat created by the combustion of the powder, nitre, charcoal, and sulphur, and in this state, is thrown out with violence, and is itself consumed. The combustion of iron is nothing more than its oxidizement, during which a brilliant fire, which characterizes so pre-eminently the Chinese fire, is produced. This oxidizement of the metal, in proportion as it is more rapid, necessarily gives rise to the phenomena of combustion, which, in this, and the generality of instances, presupposes a combination with oxygen. The fire is, therefore, more brilliant, as the combustion is more rapid, and the metal may be oxidized in a greater or lesser degree, but not to a maximum. From the effect taking place in the air, as it does not ensue, or is not seen, in the case, it follows, that the iron receives for the support of its combustion the oxygen of the air.
We have said, that the substances which compose cast-iron, are iron, carbon, and oxygen, in a peculiar state of combination. We may also conclude, therefore, that, as carbon, by combustion in oxygen gas, or in atmospheric air, which contains about twenty-two per cent. produces carbonic acid, the carbon of the iron during its combustion, is changed, by its union with oxygen, into this acid. The products, then, are oxide of iron, and carbonic acid, the latter existing in the gaseous state. With respect to the other products of combustion, arising from the gunpowder, saltpetre, sulphur, and charcoal, we have before noticed them. See Gunpowder, and the General Theory of Fire-Works.
We may remark, at the same time, that the intense heat, produced as well by the combustion of the gunpowder, as by the combustion of charcoal and sulphur, in contact with the nitrate of potassa, brings the metal almost to a state of fusion; which, being thrown off in this state, and considerably divided, is acted upon by the oxygen on all sides, causing the effect to be uniform and general.
The quantity of iron, it will be seen, which enters into the different compositions, is various, according to the particular purpose to which the composition is applied. The effect, therefore, may be varied, as we employ more or less of the iron; and the state of ignition may be affected, as the proportions of nitre and charcoal are increased or diminished. These facts are obvious, by referring to the respective formulæ, and the application of the several compositions. It is, besides, no less true, that as much care is required in selecting pure materials for every kind of artificial fire, as scrupulous accuracy, in following the proportions prescribed. Nor is this all; the mixture must be intimately made, or the effect would be doubtful and uncertain.
There is a particular manner required for preparing the composition of Chinese fire. All the substances must be passed three times through a sieve, except the sulphur, and the pulverized cast-iron. These are mixed by themselves, and afterwards with the other substances. They are turned over frequently with the hand. Cases are filled with it in the same manner as other compositions.
In order to make the mixture of the sulphur with the iron more intimate, the latter may be wetted occasionally with spirit of wine, which should contain no water, as water would tend to rust the metal, and injure its effect. The sulphur would then mix with more freedom, and the composition be more perfect. The spirit of wine, acting merely as a vehicle, afterwards evaporates; and, as it has no chemical action on either the sulphur or the metal, they would remain unaltered.
By proceeding in this manner; namely, first mixing the other substances by themselves, and afterwards the iron and sulphur, and then the whole, we form an intimate mixture throughout.
The composition, prepared in this way, makes the fire more brilliant; giving it a greater lustre than by proceeding in a contrary manner.
We are informed, that spontaneous combustion has frequently taken place, by suffering the iron and alcohol, or spirit of wine, to remain in contact; and, although this appears an anomaly, which we will not attempt to explain, yet that it is a fact, and that it has occurred at Paris, we have the authority of M. Morel.
When the cast-iron is reduced to powder, or sand, it is divided into several sorts, which are proportioned to the caliber employed. These sorts are marked or numbered, and are used as follows: For calibers under 7/12ths of an inch in diameter, No. 1; for those of 7/12ths to 10/12ths, No. 2; and for larger calibers, No. 3.
In charging with the composition, care must be taken to turn it over repeatedly at every other ladle full; because the iron, which is the heaviest substance, is liable to fall to the bottom. If the composition be not equally diffused, the fire would be irregular, and go out by puffs. This is a defect which ought to be guarded against.
The mixture of the composition for Jessamine is made in the same manner.
Chinese fire, in cases, is commonly employed in garnishing, as it is called, the circumference of a decoration, or in forming pyramids, galleries, yew trees, cascades, palm trees, or in short, in producing a variety of figures, according to taste and fancy. They are often employed in turning pieces for their last fire, in consequence of the brilliancy of their effect.
We are told, that nothing is more elegant than Chinese fire; and that it forms, in its descent, flowers of variegated beauty, which, being scattered about by the rotation of the piece, resemble the hydraulic girandole in the rays of the sun.
Chinese fire, however, has little force; and hence, when it is used, it is accompanied with other fire, as two or more jets of white fire. The latter is only employed, when the Chinese fire is to be exhibited on wheels, or turning pieces. When it is on fixed pieces, there is no occasion for them. Cases of Chinese fire, when burnt alone, will not turn a wheel.
As the effect of Chinese fire on wheels depends greatly on the motion of the wheel, its velocity should therefore be accelerated; which, although the duration of its effect would be shorter and more brilliant, may be produced by employing several cases of white fire, and communicating their fire one to the other by leaders in the usual manner.
There is no doubt, that the accelerated motion of the wheel causes the composition to burn more rapidly, in the same way as a bellows excites the heat of a blast-furnace; and, therefore, the increased brilliancy of the fire may be attributed to the greater rapidity of the combustion, which necessarily produces, in a shorter time, the oxidizement of the iron, and, at the same time, the combustion of the other substances.
With respect to the comparative force of compositions, or that power by which cases, as rockets, &c. ascend, or which gives motion to vertical and horizontal wheels, we may observe generally, that these effects depend on the compositions employed; and that the recoil, in such instances, is proportionate to the impelling power; for the resistance with which the fire meets from the air, in the immediate vicinity of the caliber of the case, causes a reaction, which produces the recoil, and consequently the motion of the wheel. That this effect depends, in a greater or less degree, on the composition we use, and the manner the case is charged, is very evident. (See General Theory of Fire-Works. Part 1.)
Composition of Chinese Fire for calibers under ten-twelfths of an inch.
Meal-powder, 16 oz. Saltpetre, 16 -- Sulphur, 4 -- Charcoal, 4 -- Pulverized cast iron, 14 --
Another of the same.
Meal-powder, 16 oz. Sulphur, 3 -- Charcoal, 3 -- Pulverized cast iron, 7 --
Another, for Palm-trees and Cascades.
Saltpetre, 12 oz. Meal-powder, 16 -- Sulphur, 8 -- Charcoal, 4 -- Pulverized cast iron, 10 --
Another, white, for calibers of eight and ten-twelfths of an inch.
Saltpetre, 16 oz. Sulphur, 8 -- Meal-powder, 16 -- Pulverized cast iron, 12 --
Another, for Gerbes of ten, and eleven-twelfths and one inch caliber.
Saltpetre, 1 oz. Sulphur, 1 -- Meal-powder, 8 -- Charcoal, 1 -- Pulverized cast iron, 8 --
It may be proper to remark, that the above formulæ are all approved; as they have been used in France, and are given on the authority of Morel and Bigot. We are informed, indeed, that these proportions produce the most perfect fire, which surpasses the fire of the Chinese. From the many experiments made in France, instituted with the view of determining the best proportions, and leading, in fact, to the improvement of the original composition, we do not hesitate to give them the preference over all others.
In the composition of wheel-cases, Chinese fire is sometimes used, and then only for decoration; but in nearly all the compositions employed, in wheel-works, for standing or fixed cases, sun-cases, &c. steel-dust forms a constituent part. The proportion it bears to other substances is various: viz. to meal-powder, as one to five, one to ten, &c. In one of the formulæ for brilliant fire, the proportion is still greater, and in another less; but by mixing seven and a half ounces of steel-dust with meal-powder, saltpetre, and sulphur in the proportion of eleven pounds, one pound two ounces, and four ounces respectively, a composition is formed, calculated to produce a brilliant fire. But as this subject will be considered, when we treat of wheel-works, standing pieces, &c. and the different compositions appertaining thereto, we would only observe, that Chinese fire should always be preferred, where the object is decidedly appearance, with brilliancy and splendour.
Sec. IV. Of Bengal Lights.
We have had occasion to mention heretofore, that metallic as well as the crude, or sulphuret of, antimony, entered as a component part into some compositions, in order to vary the effect and appearance of the flame. That this is the effect, in the composition, which constitutes the Bengal lights, is a fact well known, and to which its particular character is owing.
Bengal lights, in consequence of the whiteness and brilliancy of their flame, are considered as highly important in fire-works. The composition was a long time kept secret, and artists were at a loss to compound it, for those who possessed the secret, it appears, would not divulge it. Simple as it is, it was not known, until many experiments were made, which proved its identity with the original Bengal composition; and, since that time, it has been confirmed by the original formula. Morel assures us, that he purchased the secret.
Composition of Bengal Lights.
Saltpetre, 3 lbs. Sulphur, 13 oz. 4 dr. Antimony, 7 oz. 4 dr.
They are pulverized and mixed in the usual manner, and passed three times through a hair sieve. Any quantity may be made at one time. The composition is usually put in earthen vessels, without decorations. They may be of different sizes, and, in fact, as broad as they are high, sufficiently large, however, to contain the composition. A small quantity of dry meal-powder is scattered over its surface, and a sheet of paper is tied on to secure it. It is primed with port fire match.
The effect of this mixture is evidently that of the combustion of the sulphuret of antimony, as well as of the sulphur. The nitre furnishes the oxygen to both, and, as the combustion is rapid, the metal is oxidized, probably forming the antimonic acid, as the antimony may be oxidized to the maximum. There is another view, in which this combustion may be considered. According to the present theory of the formation of sulphuric acid, by the combustion of sulphur, and nitre in leaden chambers, it appears, that sulphurous acid is first produced, and nitric oxide gas, (deutoxide of azote), is also formed; and that the latter by uniting with the oxygen of the air is changed into nitrous acid, which is then acted upon by the sulphurous acid, and is decomposed. Part of its oxygen combines with the sulphurous acid, changing it into the sulphuric, and deutoxide of azote is reproduced. In all probability, then, in the combustion of the composition of Bengal lights, the nitric oxide itself may affect the combustion of the antimony, which, as it would be enveloped in nitrous acid vapour, arising from the union of nitrous gas and oxygen, may present, in a measure, one of those cases of combustion, in which nitric oxide acts as a supporter, affording on that account a particular phenomenon. Reasoning a posteriori, this may be affected again by the formation of sulphuric acid; for a part of the sulphurous acid may be changed into sulphuric, not by its immediate union with the oxygen of the nitre, according to the old theory, but by the decomposition of the vapour of nitrous acid. This conclusion, however, is sufficient, that the nitre is decomposed, and during its decomposition, the sulphur and antimony are brought into action; that a large quantity of caloric and light is evolved, whether from the oxygen gas of the atmosphere, or the substances themselves we will not stop to inquire; and, that, in the act of combustion, the sulphur and antimony are acidified, forming new products.
It will be seen, by examining the formulæ for the composition of the white and blue-lances, that they both contain antimony, but in different proportions: thus, in the white lance, the proportion of antimony is as one to eight of sulphur, as one to sixteen of saltpetre, and as one to four of meal-powder; and in the blue-lance, as it is composed only of saltpetre and antimony, the proportion of the latter to the former is as eight to sixteen. In the composition of Italian roses, or fixed stars, the proportion of antimony is still smaller, and is as one to ten of sulphur, one to sixteen of saltpetre, and one to twelve of meal-powder. Now, by comparing these proportions with those which constitute the Bengal light composition, they will be found to differ from those compositions, into which the same substances enter; for, in the Bengal lights, the proportion of the antimony to the sulphur is as five to nine, and to the saltpetre, as five to thirty-two, or thereabout.
The inference we draw, therefore, is, that the white lance composition differs from the blue, in containing meal-powder and sulphur, and the latter from the former, in containing no sulphur, but eight times as much antimony; that the white-lance composition varies from the Bengal light, by containing one-half less of saltpetre, one-fifth less of antimony, and one-ninth less of sulphur; and that the Bengal composition differs from the blue lance composition, in having double the quantity of saltpetre, nine parts of sulphur, (the blue-light having none,) and nearly one-third less of antimony. If we attend to these proportions of the antimony, with the other ingredients, in the respective preparations, we will find, that the difference, in the proportions of the antimony, produces, with the presence or absence of the meal-powder and sulphur, and the difference also in the quantity of the latter, the phenomena or effects which characterise them. It is thus, therefore, with this, as with other preparations; only vary the proportions, and institute new equivalents, as it were, in any particular preparation, and adopt some and reject other substances, and the effects are varied agreeably thereto; and, if improvements are to be made in any composition, they can only be effected by experiment, and the investigation of the effects of new proportions, a comparison of which, with the effect of any particular composition, prepared according to a given formula, can alone determine the relative value of any new formula.
Sec. V. Of Roman Candles.
Roman candles are formed on a roller seven-twelfths of an inch in diameter, and are generally fifteen inches in length. They are choaked at one end, and tied in the usual manner. According to the nature of the charge, which we shall mention, their effect is to throw out brilliant stars, to the height of one hundred and more feet, and when arranged with marrons, they finish with a report.
After the cases are formed, and ready to be filled, the operation is performed with expedition, by tying a number of them together, and charging them in that manner. The cases are charged with the rocket composition, heretofore described, in the following way: A ladleful of composition is put in, and rammed, using seven or eight blows with the mallet; a small spoonful of powder is then added, and afterwards a moulded star. This star should fit the caliber of the case. More of the composition is then added, then meal-powder, and afterwards a star, and these are repeated in the same order, till the case is completely charged. Care must be taken in observing this order, otherwise the effect would be destroyed. In striking with the mallet, attention must also be paid, that the blows are not too violent, or the star might be destroyed. When the cases, or candles, are charged, we untie them, and roll some coarse paper round each end of them, at the extremity, and round the choak.
We may remark, that in the charging of Roman candles, as their effect depends greatly on the appearance of the stars, which issue out in succession, too much care cannot be used in preserving the star composition entire. To do this, much art is required in putting in, and ramming, the rocket composition, so as not to injure or break it. The quantity of gunpowder to each star must be small, otherwise it might burst the case. Roman candles may be fired singly or several at a time, according to the effect required. To fire one in a chandelier, for instance, it is only necessary to prime it with priming paste; but, if we wish to form batteries in an artificial fire-work, in order to produce a variety, or to mount them on fixed or moveable pieces, we may, if necessary, terminate their effect with marrons, which may be effected by uniting them in such a way as to make the fire of the one, at a given time, communicate to the other. This communication is usually made through the choak, by attaching a match, which is carried to the mouth of the marron; so that, when the candle has burnt out, the last portion of the fire may pass to the marron, the effect of which is instantaneous. If necessary, priming paste may be used to facilitate the communication of the fire. The marron may be fixed directly under the bottom of the candle, by making the whole solid by a paper cylinder, which fits over the ends of both.
The mosaic candles, as well as mosaic simples, are formed in cases of the same thickness as sky-rockets, from which they differ in the introduction of stars along with the composition. We may remark, also, that they are rolled without pasting; and although Morel recommends choaking the cases, yet a writer of more recent date, M. Bigot, whose practical knowledge must be great, recommends plugging them on the stick or roller. This is done by merely turning the end down about half an inch, and then beating it. Before the composition is added, he advises, also, the introduction of two or three fingers' thickness of clay, which is rammed very solid. This answers for a base, and supersedes the necessity of choaking. If, as we before remarked, it is necessary to communicate fire from this end to a marron or any other case, the clay must be bored to the composition, and quickmatch inserted; or, instead of this, the case itself, above the clay, may be perforated, and a communication in this way made.
Besides the ordinary Roman candles, intended expressly for exhibition, there is another preparation, which goes under the name of the incendiary Roman candle, used for the purposes of war. This preparation is composed of three parts of sulphur, four parts of saltpetre, one part of antimony, and half a part of meal-powder; but this, together with the incendiary stars, we purpose to consider when we treat of Military Fire-works.
Sec. VI. Of Mosaic Simples.
Mosaic simples are in reality nothing more than a variety of the Roman candle, being formed in the same manner, and of the same composition, except that the moulded stars are different, and produce another effect. The mosaic simples produce merely a tail, or spout of fire; whereas the Roman candle throws out a brilliant star. They may be used with marrons in the same manner as the Roman candle. The length of the case is fifteen inches, and seven-twelfths of an inch in diameter. Mosaic simples are very appropriate to terminate a piece. A number of cases may be used by placing them in such a manner, that their fires may cross each other, an effect more striking than the ordinary mode of exhibition. This may be accomplished by arranging them, two and two, to a horizontal stick, observing that their mouths are up, and that they cross each other. They are lashed to the stick, and leaders are carried from the mouth of one to the mouth of another. This communication is so managed, that two pieces discharge at the same time. They may be employed in a variety of ways, according to fancy.
Sometimes pyramids forty or fifty feet high are furnished on each side, with cases of mosaic simples, with a star at the summit, and white and coloured lances differently dispersed.
The curtain of fire, produced by so many cases, the height to which it rises, the appearance of the star with the variegated and diversified effect of the coloured lances, all contribute to the splendour of this arrangement.
Composition of the Mosaic Moulded Stars.
Saltpetre, 4 oz. Sulphur, 4 dr. Meal-powder, 16 oz. Charcoal, 3 --
Or in proportional parts: saltpetre, four parts; sulphur, half a part; meal-powder, sixteen parts; and charcoal, three parts.
These substances, being finely pulverized, and intimately mixed in the usual manner, are combined with gum-water, &c. as directed for preparing stars, and cut into lozenges, which are then rolled in priming powder, and dried in the shade.
Sec. VII. Of Mosaic Tourbillons.
We may merely remark, as we have mentioned tourbillons heretofore, that the cases for the mosaic tourbillons, by which name they are designated, are seven inches in length, five-twelfths of an inch in interior diameter, and nine-twelfths in exterior diameter; and that the composition with which they are charged, is composed of sixteen parts of meal-powder, and three and a half parts of pulverized charcoal. See Tourbillon.
Sec. VIII. Of Hydrogen Gas in Fire-Works.
M. Diller, some years since, exhibited at the pantheon of Paris, artificial fire produced by the combustion of hydrogen gas. From the short account we have of this exhibition in the Dictionnaire de l'Industrie, vol. iii, p. 39, it seems, that he employed three different airs, or gases, and produced three different flames: viz. white, blue, and green, which were made by the mixture of the three gases; and that he represented very perfectly, suns, stars, triangles, the cross of Malta, and sundry figures of animals in motion.
We may remark, that, if hydrogen gas be pure, the flame is of a yellowish-white; but this, however, is seldom the case, as the gas is always more or less impure, and, according to the substances it may hold in solution, so is the flame tinged. It is most usually reddish, because the gas holds in solution a little charcoal. In Cartwright's fire, ether is always mixed with the whole, or a part of the gas, which is brought to the state of vapour by the application of a gentle heat, or even by immersing the bladder of gas, which contains the liquid ether, in hot water.
When combined with arsenic, in the form of arsenuretted hydrogen gas, hydrogen burns with a blue flame; combined with phosphorus it takes fire spontaneously, producing a white flame with a beautiful corona, caused by the formation of water; and when combined with sulphur, forming sulphuretted hydrogen or hepatic gas, it burns with a bluish-red flame, and a quantity of sulphur is deposited. Various mixtures of hydrogen with other gases, in due proportions, will produce different coloured flames; so that, by paying attention to this circumstance, the same variety of appearances may be produced, as in Diller's exhibition.
Bladders, (or sacks made of oiled silk, which are preferable), when filled with gas, and connected with tubes, revolving jets, &c. bent in different directions, and formed into various figures, and pierced with holes of different sizes, will, when pressure is applied, allow the gas to pass through the different tubes, jets, &c. which, when inflamed, will represent the sun and stars. If to this be added, triangular tubes, tubes in the form of the cross of Malta, or any other figure, they being pierced in their sides with a great number of holes not larger than the point of a pin; it is obvious, that fixed pieces may be represented, as well as revolving ones. In this manner, Diller must have made his exhibition.
Hydrogen gas is usually made, by pouring on zinc, or iron filings, in a gas bottle, sulphuric acid diluted with six times its weight of water. The latter is decomposed; its oxygen unites with the metal, and while the oxide is taken up by the acid, the hydrogen passes off in the form of gas. The gas may be received directly in the bladder or bag.
The inflammable air pistol is nothing more than a hollow metallic cylinder, or an instrument in the shape of two cones joined base to base, and furnished with a touch-hole, and handle. This pistol is filled with a mixture of hydrogen and oxygen gases, or in lieu of the latter, atmospheric air; a plug or stopper is put in the caliber, and, when the touch-hole is brought in contact with a lighted taper, an explosion will take place, and the plug be sent out with much force. The same effect may be shown by passing the electric spark over the touch-hole, and hence, on an insulated stool, a person, charged with electricity, may set it off by the finger or nose. This pistol is usually called the Voltaic pistol, from Volta, who is said to have invented it.
M. Biot (Traité de Physique Experimentale, &c. tome ii, p. 435) describes the Voltaic pistol as a metallic vessel of a spheroid shape, furnished with an aperture and pipe, and with a conductor for the electric fluid, which passes through the middle of the vessel. This conductor is insulated, as it goes through a glass tube, and extends to within an eighth of an inch of the middle; and directly opposite to this conductor is a metallic wire, having, like the first conductor, a small metallic ball on its end. This conductor is placed a short distance from the first; so that, when the electric fluid is conducted, it passes from one ball to the other within the pistol, and hence inflames the hydrogen gas. With respect to the form of the pistol, it is of no moment whether it be cylindrical, conical, or globular, as the effect is the same, provided that it contain a sufficient quantity of gas, and the spark is conveyed through the gas, or the gas is inflamed by a vent. The air pistol described by Brande (Brande's Chemistry) is cylindrical, or rather in the shape of a cannon, and, where the touch-hole should be, there is an insulated conductor, which conveys the spark to the interior.
The Voltaic lamp is also a contrivance by which hydrogen gas is inflamed by the electric spark, which sets fire to a taper. The original lamp has been greatly improved, and simplified. The eudiometer of Volta is another contrivance by which hydrogen gas is burnt, in a strong tube, by the electric spark.
The detonation of inflammable air may be shown over a pneumatic tub, by filling metallic gas-holders with a mixture of hydrogen gas and atmospheric air. When flame is brought in contact with the mouth of the gas-holder, an explosion will immediately take place. Soap-bubbles, blown with hydrogen gas, mixed with atmospheric air, will take fire, on presenting a lighted taper, and give a slight explosion. The ascension of these bubbles demonstrates, that the gas is lighter than atmospheric air, and it is its extreme levity that fits it for the purpose of filling balloons. It may be made twelve times specifically lighter than atmospheric air, by passing it over dry muriate of lime, in order to absorb the moisture it may contain, provided the gas be free from carbon, or carbonic acid.
Light carburetted hydrogen gas, or fire-damp of miners, is that gas, which so often formerly produced many dreadful accidents by its explosion. The invention, by Sir H. Davy, of the safety-lamp prevents this effect.
The principle of this most valuable discovery, appears to be altogether in the fine metallic gauze case, which surrounds the flame of the lamp; so that, as it is found by numerous and repeated experiments, the inflammable air, if present, cannot take fire outside of the gauze; in other words, the flame, in the interior of the case, is prevented from setting fire to the exterior atmosphere, however explosive it may be.
Hydrogen gas, in combination with carbon, is not only generated in mines and coal pits, (in the latter of which, it is the most abundant), but is frequently found on the surface of springs in the form of bubbles, usually however combined with sulphur; and in many places on the surface of the earth. It may be inflamed by a candle. The burning springs consist of this gas which is set on fire, and the combustion is kept up by a constant supply of gas from the same source. In the East, this gas is very often conveyed under ground through hollow reeds, and is constantly kept burning. At other times, it is conveyed to the sacred temples, as with the Zoroasters, and burnt as holy fire; and in some countries, it is so abundant, that the natives employ it as fuel for boiling their pots. It is found in different parts of the United States. A striking incident, showing its effects, occurred lately near Cincinnati, in the state of Ohio. It appears, that, in making an excavation, and boring for salt water, the workmen penetrated their augur into a cavity, which contained an abundance of gas, and which, with the water, made its way to the excavation. Not suspecting that the gas was inflammable, or being unacquainted with it, and apprehending no danger, they brought a lighted taper; and the gas, being mixed with atmospheric air, exploded with a noise so considerable, that it was heard several miles in the neighbourhood. The men were much burnt, some of them dangerously.
The gas was afterwards inflamed by applying a taper, as it rose in bubbles from the surface of the water.
The philosophical candle is nothing more than hydrogen gas set on fire as it proceeds from a capillary tube, being formed in a bottle to which the tube is attached. The most brilliant flame, however, is produced by hydroguret of carbon, or olefiant gas.
Inflammable air is often generated in the stomachs of dead persons, for, on applying a lighted candle, the vapour has been known to take fire. Dr. Swediaur relates some instances of the same kind, but in living persons, in which the urine of the by standers was made use of. According to several authorities, combustion has been known to take place spontaneously in living persons. Lair, however, is of opinion, that, in these cases, it must have occurred by some slight external cause, such as the fire of a candle, taper, or pipe. There can be no question as to the developement of hydrogen gas.
Morse, (Universal Geography, article Persia, p. 588), after mentioning the Persian guebres, the disciples and successors of the ancient magi, and followers of Zoroaster, speaks of a combustible ground about ten miles distant from Baku, a city in the north of Persia, as the place for their devotion. This ground contains several old temples, and is remarkable for the quantity of inflammable air it emits, which is employed to produce the sacred flame of universal fire. If the ground be penetrated with a stick, there will issue out such a prodigious quantity of inflammable air, as, when lighted, will burn for a considerable time. This gas, we remarked, is employed there for lighting, cooking, and other purposes. The naphtha districts, in Persia, furnish this gas in abundance. See Naphtha.
A Sandusky (Ohio) paper states, that, about one mile and a quarter from Milan, is a place just in the edge of the water of Huron river, where there is a current of inflammable gas, that burns with a clear bright blaze, and is in sufficient quantity to light ten houses.