Part 9

The annexed fig. 68 gives you one of the simplest forms of the horizontal wheel. A wheel made according to this plan will require four wheel-cases and a case of Chinese fire long enough to last during the combustion of two of the wheel-cases. The quick-match is put to it in the following manner:—Simply connect the first and second wheel-cases by carrying a quick-match from the tail of the first to the mouth of the second. Then from the tail of the second carry two “leaders” (as these pieces of quick-match are called), one to the third wheel-case and the other to the perpendicular case of Chinese fire, which will thus be ignited at the same moment with the third wheel-case; and to complete the wheel carry a leader from the tail of the third to the mouth of the fourth case.

[Illustration:

Fig. 68. ]

The case of Chinese fire which I should recommend you to make for this and for other horizontal wheels is one of the 2-oz. size, nine or ten inches in length, and filled with composition No. 4, given in paragraph 41. It is to be affixed to the wheel thus:—There must be a small projecting piece of wood left by the turner at the top of the nave of the wheel, about an inch in height and five-eighths of an inch in diameter, and if an inch of the case be left unoccupied by the composition at its unchoked end, this end can be squeezed over the wooden point mentioned above, or can be glued on to it if you think it desirable.

Another and very amusing variety of the horizontal wheel is that which my next illustration represents, and which is sometimes called the “capricious” wheel. This carries six wheel-cases and one Chinese fire case. The wheel-cases are arranged in the following manner:—All the cases are placed at an angle with the plane of the wheel’s revolution; the three upper ones have their mouths inclined upwards, the three lower ones downwards. Care of course must be taken that all the mouths, whether inclining upwards or downwards, be turned _in the same direction_. They are connected thus:—Make one of the lower cases the first to be fired; from the tail of this carry a leader to the nearest of the upper cases, which will then burn second; from the second carry a leader to another of the lower cases; then from this to another of the upper ones. From this fourth case carry three leaders—one to the remaining upper case, one to the remaining lower case, and one to the case of Chinese fire.

[Illustration:

Fig. 69. ]

The effect of this wheel is exceedingly laughable. It does not revolve so rapidly as the simple horizontal wheel mentioned above, the cases of which are perfectly horizontal. The impression that its performance always gives one is, that it is determined to do something violent: that if one direction of fire will not answer it will try another. Each succeeding case sends it round more rapidly than the last, on account of the decreasing weight as the cases burn out; and if the two cases which are to burn with the case of Chinese fire be filled with composition No. 1, given in paragraph 44, the fury of the wheel will at the last seem to know no bounds.

It is necessary, however, to see that the hole into which the iron spindle is to pass is truly bored and is long enough, and that the spindle _at the top_ of the post is straight and strong. This spindle should pass into the nave of the wheel five inches at least.

Let me press upon you one or two important hints. _The case, or cases, that burn last on each wheel must always have their ends closed with clay, or some incombustible substance._ If this advice be neglected your wheel is pretty certain to fail.

I have drawn at fig. 70, a fac-simile of the spindle which I use for all vertical wheels. It is made to screw into an iron which is represented at fig. 71, which iron is fixed by screws to my post in the manner shown at fig. 72. The post I employ stands about ten feet out of the ground. Into its top is driven another spindle, on which my horizontal wheels turn. Both these iron spindles should be made of quarter inch iron rod.

You will find the spindle drawn at fig. 70 very much more convenient than one simply driven into the post, and having a “nut” at its end to screw and unscrew; for it is more than probable that on a dark night, when you are taking down one wheel that has been fired, and putting up another, you will drop the “nut,” and feel considerably at a loss without it. And besides this, you can by this means always remove the spindle, and protect it from rust. Your post should be very steady.

Mr. Darby will supply you with any frameworks of wheels, made to any pattern that you please.

I shall speak of some other wheels when we are sufficiently advanced in pyrotechnic proficiency to be able to attempt the manufacture of _all_ their component parts.

LANCES—WHITE AND COLOURED.

49. We have now, in the course of our pyrotechnic investigations, arrived at a point where it becomes necessary to know something more than we have already learned about _coloured fires_. I have spoken hitherto only of those coloured compositions which are employed in the manufacture of rocket and Roman-candle stars. These compositions must for the most part be confined in their use to that purpose, because they are, in almost all cases, far too rapid in their combustion for the purposes of which I am now about to speak.

I now proceed to treat of Lances, white and coloured, for making up devices, such as names, crests, mottoes, wreaths, &c., &c.

Now, there are a great many formulæ given for compositions employed to decorate other fireworks, or to form designs of any kind in white or coloured fire, with which it may be advisable for my readers to be acquainted, in order that they may have the opportunity of selecting for themselves, and of providing themselves with, a colour of that particular shade and character which is best adapted for the working out of the design determined upon.

In the first place I will speak of those fireworks which are properly called “lances.” These are small cases, generally made about three-sixteenths of an inch in diameter, that is round a piece of glass or brass rod or tube of that size (tubes are always best for these small formers). The cases are about two or two and a-half inches long, with one end pinched or turned in. Two rounds of thin demy or double crown white paper, pasted, will give sufficient thickness and substance for the case. The cases, when dry, are to be filled with either of the following compositions by means of the funnel and wire apparatus illustrated at figs. 34 and 35:—

COMPOSITIONS FOR LANCES.

_White._

No. 1. Nitre 16 parts. Sulphur 8 „ Meal-powder 6 „

Or,

No. 2. Nitre 16 „ Sulphur 4 „ Meal-powder 6 „

Or,

No. 3. Nitre 12 „ Sulphur 4 „ Sulphide of antimony 3 „

Or,

No. 4. Nitre 72 „ Sulphur 18 „ Regulus of antimony 33 „ Realgar 1 part. Shellac 1 „

Or,

No. 5. Nitre 96 parts. Sulphur 24 „ Regulus of antimony 48 „ Realgar 6 „ Shellac 1 part.

These for the most part give a bluish-white flame, and when employed in cases of the size mentioned above, burn slowly, and will last as long as this species of firework is required to last.

_Yellow._

No. 6. Chlorate of potash 72 parts. Oxalate of soda 60 „ Stearine 6 „ Sulphur 6 „

Or,

No. 7. Chlorate of potash 40 „ Oxalate of soda 16 „ Shellac 8 „ Stearine 3 „

_Green._

No. 8. Chlorate of potash 60 „ Nitrate of baryta 41 „ Calomel 49 „ Powdered sugar 30 „ Shellac 1 part.

Or,

No. 9. Chlorate of potash 63 parts. Nitrate of baryta 50 „ Calomel 50 „ Sugar 32 „ Shellac 1 part.

The green colour is never very decided when the compositions are employed in cases so small as those spoken of above. But by far the best composition to be used in these small cases is one containing a rather costly ingredient, which is the chlorate of baryta. The usual price of this salt is about 8s. per lb., or rather less. It gives a magnificent colour if it is pure, but if not, it is not worth buying. I give you the formulæ in which it may be employed, in case you should require a very brilliant emerald green in these small lances. They are—

No. 10. Chlorate of baryta 18 parts. Calomel 7 „ Shellac (very fine) 3 „

Or,

No. 11. Chlorate of baryta 24 „ Stearine 3 „ Sugar (very fine) 1 part.

Compositions containing chlorate of baryta are perfectly safe _where no sulphur is employed_. The salt itself is not at all deliquescent. A very good formula besides the above is one containing three proportions of chlorate of baryta, and one of powdered sugar. We will next speak of RED LANCES.

_Red Lances._

No. 12. Chlorate of potash 13 parts. Nitrate of strontia 10 „ Calomel 8 „ Shellac 3 „ Dextrine 1 part. Chertier’s copper 1 „

Or,

No. 13. Chlorate of potash 12 parts. Nitrate of strontia 12 „ Calomel 6 „ Shellac 4 „ Chertier’s copper 1 part. Charcoal (fine) 1 „

A good rose-coloured fire may be produced by a composition containing the oxalate of strontia, which, though not to be met with everywhere, is a valuable salt on account of its extreme dryness and fineness. The formula given next has the merit of being rapid in its combustion. Should it be thought _too quick_, decrease the proportion of chlorate of potash, or increase that of calomel. The increase of calomel has the effect of deepening the colour, but, at the same time, of diminishing the reflective power of the light.

_Rose-coloured Lances._

No. 14. Chlorate of potash 24 parts. Sulphur 2 „ Stearine 3 „ Oxalate of strontia 4 „

This composition will remain good for any length of time, and has therefore a great advantage over those which contain the nitrate of strontia. And here I may as well remind you of the importance and necessity of having this latter salt perfectly dry and fine, otherwise you will be disappointed of your intended effect in the ordinary red-fire compositions.

For the blue lances you may use composition No. 8, given in paragraph 23.

But there are also two other formulæ which you will find very serviceable and effective:—

No. 15. Chlorate of potash 32 parts Chertier’s copper 12 „ Calomel 40 „ Sugar 25 „

Or,

No. 16. Chlorate of potash 6 „ Chertier’s copper 1 part. Calomel 5 parts. Sugar 4 „

For the preparation of a purple fire for these little cases, you cannot do better than use that given for Purple Rocket Stars.

There are still two other colours which you may perhaps find useful and ornamental, and without which my list would not be complete. They are the violet and the lilac tints. The violet is at No. 17, and the lilac at No. 18:—

No. 17. Chlorate of potash 26 parts. Calomel 24 „ Carbonate of strontia 4 „ Chertier’s copper 3 „ Sugar 14 „

Or,

No. 18. Chlorate of potash 12 „ Prepared chalk 4 „ Sulphur 5 „ Calomel 3 „ Sulphide of copper 10 „

With regard to the use of sugar in pyrotechnic compositions it must be borne in mind that it is a substance which readily attracts damp, so that it must be kept in a closely-corked or stoppered bottle. It should be reduced to powder in a very dry mortar, and then sifted through very fine muslin, to fit it for pyrotechnic uses. And the mention of muslin here reminds me of a fact which experience has brought to light, and which you will find it highly convenient to remember. All those powdered salts and pyrotechnic ingredients which clog the meshes of a wire sieve will easily pass through a sieve made of muslin. For instance, powdered stearine, shellac, sugar, and the salts of strontia and baryta will be found to sift much more readily through muslin, _provided the muslin be dry and clean_. This will enable the amateur pyrotechnist to fit himself up with sieves of any fineness at a very small cost. He will require only a tin or zinc drum, about 6 inches in diameter, and 4 inches high, with a wire ring round each end. Over one of these ends he can stretch a piece of muslin of the required thickness, and fasten it with a strong elastic band. Or he may have a metal ring made large enough to fit over the muslin and round one end of the drum, which he can remove when a change of muslin is necessary. I do not by any means recommend this kind of sieve for sifting such things as meal-powder, charcoal, or sulphur; for I consider a receiver, made to fit on to the sieve, indispensable in the case of sifting these articles. The dust arising from this operation will otherwise find its way into your eyes, and nose, and clothes, and over everything in your room.

It is, perhaps, unnecessary for me to add that all the above compositions must be made up with the greatest exactness, and no ingredients must be used but such as are thoroughly dry and in the finest powder. The most successful pyrotechnists have never been able to produce proper effects, even with the purest and best materials and chemicals, unless those materials have been first reduced to the necessary state of fineness and dryness, and then mixed till they have become most intimately incorporated.

We will now suppose a sufficient number of these lances to be filled with the selected compositions. They must be primed precisely in the manner described under the head of “Golden Rains.” When finished they will be about two and a-half inches long, and about equal in size to an ordinary drawing-pencil.

[Illustration:

Fig. 73. ]

The first thing to be done is to decide upon your design. This, I presume, will not be very large. I need not furnish you with a series of suggestions for these designs, for the chance is, that, after all I can say, the one which you wish to execute will be one of your own conception, or at all events, one which you would rather carry out in your own way. But I give here a plain sample of the work (fig. 73), which is merely intended to make clearer my verbal directions. _The letters should not be less than ten inches high._

In the first place you must either procure a board of sufficient size for your design, or you must make a wooden framework of the shape that you require. Suppose the design to be a V.R.: now either sketch this out upon one side of your board, or, if you wish to have it larger than a board will allow, make a plain rough framework describing the letters. When this is done, decide upon the distance at which you can place the lances one from another. This distance is generally about two inches, but no exact rule can be laid down, for so much depends upon the sort of design that you think of executing, and upon the scale of its size.

I will now suppose that you have your design carefully drawn upon the board or framework. Upon the outlines of your sketch make little pencil circles wherever you intend to place a lance; and, as far as it is possible, arrange that the lances shall be equidistant one from another. Of course the prime object of the arrangement must be to make the outline of the letters, figures, &c., as plain and bold as possible. Now with a centre-bit, or, what is better, a pin-bit, _bore a hole about a quarter of an inch deep_ where your circles are pencilled. These holes must be of such a size that the closed ends of the lances will fit easily into them. When you have completed this operation, get either some glue or some of the mixture of size and red lead which I have recommended before; and when it is liquid, dip into it the closed end of each of the lances. Enough of the mixture will adhere to the lances to allow of their being secured firmly in the holes that you have bored. In a very short time all will be hard and dry, and you will then have a series of lances projecting at right angles with your board or framework, each having its mouth primed, and all being of the same length.

The only thing that remains now to be done is to clothe these primed mouths with quick-match. This is by no means difficult, but requires a certain amount of patience. Take a length of match in its case, and, having exposed one end of the black match itself, put a small pin through it into the priming of one of the lances. This will fasten it down, and at the same time will insure its ignition. Then lead the quick-match on to the next lance, cutting away with scissors a piece of the under side of its case, to allow the match in passing to touch its priming. Put a pin through the match into the priming of this lance also, and so on till all are clothed. If more of the casing of the match has been cut away than is necessary, it will be well to paste small strips of paper wherever this has happened, as any exposure of the black match will endanger the piece, rendering it liable to ignition from the sparks of other fireworks. This piece of caution must be carefully attended to, because lance-work is generally employed with the finale of an exhibition, when a great many pieces are going off at once, and when the effect of the whole may be easily spoiled by the untimely firing of one part.

The arrangement of colours in lance-work must, of course, be left entirely to the artist himself. It matters not what the arrangement is, if the colours be only properly contrasted. Remember that the most effective and striking contrasts are blue with yellow, red with green, purple with red, white with violet or red.

In the case of letters, or a monogram, a border of an oval or circular shape adds very much to the effect. This border should be of a different colour to that used for the letters, &c.

Lance-work is not very largely used in pyrotechnic exhibitions; one specimen of it in each display is quite as much as is generally seen. But it certainly is a pyrotechnic feature, and on that account must not be passed over. Lance-work is generally accompanied in its exhibition with Roman candles, or with some arrangement of gerbes to take off what would otherwise be its bare appearance. When introduced as a centre to some framework of sparkling fire it is very beautiful, particularly if colours be employed in it.

I need hardly add that when it is fired the framework is to be placed vertically, and _the lances are to burn horizontally_. It is a good plan to paint the framework black.

COLOURED LIGHTS.

50. We may now go on to deal with another branch of this part of our subject—viz., that which concerns the manufacture of coloured lights for illuminating wheels, or set-pieces, or any larger kind of firework. This species of colour is perhaps more useful in exhibition work than any single firework that can be named, for there are few set-pieces, or wheels, or designs of any pretensions to which these coloured lights cannot be adapted, and adapted, too, with a very enhancing effect.

Their preparation is exceedingly simple. They are generally made in two sizes only; these are the two-ounce and the one-ounce sizes. The cases are made of cartridge or foolscap paper and are about two inches long for the two-ounce size and one inch and three-quarters for the one-ounce size. Used-up copy-books furnish excellent paper for making these coloured light cases. Three or four rounds of the paper will give you ample thickness for the case. The paper should be pasted _all the way along the strips_. When the cases are thoroughly dry, ram into the bottom of them some dry powdered clay; this will make a close end, and will also furnish an incombustible part by which the case may be tied or fastened to its place. The clay is often rammed so as to fill the case nearly half-way up; but, of course, the space left for the composition will depend upon the length of time that you wish the colour to burn.

There is some exactness and nicety, besides a certain amount of actual experience, required for the proper adjustment of these colours to the cases in combination with which they are to burn. The coloured light should be under control, so that it makes its appearance and introduces its intended effect at the right time, and lasts only as long as it is required to last. I will now give a few formulæ for these larger coloured lights. These, if made up with ordinary care and their ingredients thoroughly mixed will produce magnificent colours, both as regards depth of tint and brilliancy of reflective power. The compositions given above for lances are for the most part of too rapid combustion to answer well in these larger and more open cases, but the following will be found to succeed admirably if the chemicals used be only pure and dry, and properly incorporated:—

WHITE LIGHTS FOR DECORATION. No. 19. Nitre 4 parts. Sulphur 1 part. Sulphide of antimony 1 „

Or,

No. 20. Nitre 4 parts. Sulphur 1 part. Meal-powder 1 „

These will give the ordinary bluish-white light, and compositions made from them will remain good for any length of time.

The yellow lights may be made from the formulæ given under the head of Lances.

The following will produce the _green_:—

No. 21. Nitrate of baryta 80 parts. Chlorate of potash 32 „ Sulphur 24 „ Calomel 16 „ Charcoal (fine) 3 „ Shellac 2 „

The drawback to all green colours burnt in cases is that the combustion of the case itself impairs to some extent the purity of the tint of the flame. Cases, therefore, which are to contain green fire must not be made unnecessarily thick. Composition No. 21 gives by far the best colour that I have yet seen for this purpose, and when contrasted with a good red is all that one need desire.

The two next compositions will furnish exceedingly beautiful red colours. It is best to make them up only a short time before using them, as their effect is much more brilliant when quite freshly mixed; and, besides, the nitrate of strontia becomes damp after a time, particularly in the autumn and winter months, in which case it will produce only the effect of disappointing you. The compositions are both perfectly safe, since they contain no sulphur, and are on that account entirely free from all liability to spontaneous combustion:—

_Red Lights._ No. 22. Chlorate of potash 32 parts. Nitrate of strontia 48 „ Calomel 20 „ Shellac 12 „ Chertier’s copper 4 „ Charcoal (fine) 1 part.

Or,