Part 10

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.

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,

No. 23. Chlorate of potash 84 parts. Nitrate of strontia 80 „ Calomel 51 „ Dextrine 22 „ Shellac 18 „ Chertier’s copper 4 „

Of these two formulæ, No. 22 is the one that I generally employ. It produces a very brilliant colour, which is _almost scarlet_, and forms, in my opinion, the best contrast both to the green and purple lights. No. 23 gives a deep rich crimson, which may also be found very effective occasionally. Dextrine, which enters into its composition, is always to be had in very fine powder, and therefore it will give you no trouble to bring it into the proper condition for use. It is very cheap, being sold generally at from 1s. to 1s. 6d. per pound. You will require only a very small quantity of it.

We now come to the last of our colours for making these decorating lights, and that is the purple.

_Purple._ No. 24. Chlorate of potash. 28 parts. Chertier’s copper 28 „ Calomel 13 „ Shellac 8 „ Stearine 1 part.

Or,

No. 25. Chlorate of potash 40 parts. Calomel 28 „ Chertier’s copper 28 „ Dextrine 10 „ Stearine 3 „

No. 26. Chlorate of potash 26 „ Chertier’s copper 24 „ Calomel 14 „ Shellac 7 „

All of these three formulæ produce good colours. I think that I am rather inclined to give the preference to No. 25, on account of the very effective contrast that it makes when employed to burn with the red at No. 22. These three colours are perfectly safe, for the same reason that I stated above when speaking of the red lights.

I trust that the formulæ which I have now given will be found to supply all that you will require in this department of pyrotechny. The compositions have all been used by me, and I can therefore speak from actual experience of their respective merits, and so you will be pleased to remember that if they do not succeed in your hands the fault will lie either in the condition, perhaps the impurity, of your chemicals, or in your own manipulation. I can answer for the receipts; all that is necessary on your part is a scrupulous attention to my directions.

And here let me put in a word of caution. Where you see “_Red Lights, Green Lights, Purple Lights_” written over the formulæ above, you are to remember distinctly that I use the word “LIGHTS” to distinguish this branch of pyrotechny, and these compositions, from those which I mean to treat of under the title of coloured “FIRES.” By coloured lights I mean small cases, of the 1 or 2-oz. size, filled with either of the above compositions from No. 19 to No. 26 inclusive. _These compositions are not adapted for the purpose of producing coloured FIRES, such as are employed to light up gardens, avenues, buildings, &c._ They are to be confined to their own use, which is _the decoration of wheels, or of any large and complicated exhibition fireworks_. For this purpose they _will_ answer _well_, and for the other _they will not answer at all_. And having now explained the distinction between coloured LIGHTS and FIRES, I must ask my readers not to lay the blame upon me if, when employing my compositions for purposes for which they were never intended, they find they do not succeed.

But we have still to speak of the way in which these coloured lights are to be fastened to the pieces which they are designed to decorate. The most common way of doing this is to drive a nail into the wooden framework of the piece at the place where you wish to place the coloured light, and to tie the case which contains it to this nail. Two nails, like “two heads,” are better than one, and the case may be secured as shown in the annexed sketch (fig. 74). A represents the coloured light case; B the string which is passed round its lower clayed end, by means of which it is secured to the two nails, C C, which are driven into the wooden framework. This mode of fastening is very simple and effective for attaching the coloured fire cases to the framework of a _fixed_ piece. But in the case of a wheel, or any piece which has motion, it is, in my opinion, very desirable to give them a position like that of the _wheel-cases_—_i.e._, to let them revolve with their mouths in the opposite direction to that of the motion of the wheel. This is easily done, either by fastening them between the spokes of a large wheel, or, in the case of a small one, by driving in a longer nail than is necessary, and bending down the head of it in the desired direction, and fastening the coloured light case to this bent part (fig. 75).

By this means you will have no difficulty in attaching these little decorations in any place, to any part of the framework of your piece, or in any direction. The object of turning the mouth away from the direction in which the piece moves is that the resistance offered by the air during its revolution may not interfere with the easy combustion of the coloured light.

But we have yet to say a few words about the filling these 1 or 2-oz. cases, and their priming.

The compositions used for this purpose do not require, it must be remembered, to be _rammed_ into the cases; they only need be _pressed in_ so firmly that their motion during combustion shall not shake them out. Of course they should be _uniformly_ pressed in, and this is simply done by pressing in only a small quantity at a time.

With regard to their priming, this may be done in either of the following ways—by smearing into their mouths some wetted meal-powder, or, what is better, by pressing into their mouths a piece of quick-match, and then pressing a little of the coloured composition over that, and allowing the end of the match to project about half-an-inch. But in whatever way they are primed they must have two rounds of some thin paper pasted round their mouths, and projecting an inch or so beyond them, into which the leaders can be tied which are to connect them with the other cases of the piece.

In the case of small wheels, in which only one of these coloured light cases is to be employed, it will be advisable to fill it with compositions of different colours. Press in first enough red-light composition to fill one-third of the case; then enough purple to occupy another third, and fill the remainder of the case with green composition. By this means you will be able to vary your effects to any extent.

I now wish to give you directions for making a very beautiful and effective firework, in which these coloured lights play a prominent part. I must refer you to the page of illustrations which accompanies this paper, in order that you may have no difficulty in understanding the directions which I am now about to offer.

In its general working the piece is very similar to that which I have described under the name of “Brilliant Wheel” at paragraph 43. But it is at the same time a great improvement upon the one there spoken of. Cut a piece of deal or beech board into the shape drawn at _A A_. (fig. 76). This should be at least half-an-inch in thickness, and not less than three feet in length. When you have shaped it as you intend to leave it, find its centre, the point at which it balances. Through this point bore a hole of such a size as will easily admit the iron spindle which screws into your firework post (fig. 70). At each end of this wooden frame place three wheel-cases, taking care that the position of the mouths of these cases is so arranged that their driving power shall all be in one direction. A quick-match leader is to be carried from the _tail of the extreme case at each end to the mouth of the next_, and then from the tail of these to the mouths of the third at each end.

Two more pieces of wood (represented at _B B_. fig. 76) will now be required, each about twelve inches long, five-eighths of an inch wide, and three-eighths of an inch thick. They must have a hole bored through them, into which a spindle or smooth round nail can pass easily. _But this hole must not be in their centre_; it should be bored about four inches from one end, which will leave eight inches on the other side of the hole. Through these holes drive a smooth round nail into the long framework of the piece, exactly half-way between its centre and the innermost wheel-cases. The object of hanging these two pieces _not_ by their centre of balance is that one end being longer, and therefore heavier, than the other, may cause the pieces to fall round by their own weight, as the firework makes its revolutions. To these two pieces coloured lights are attached at each end in such a position that they shall project horizontally at right angles with the pieces _B B_. This will be seen clearly by reference to the drawing at _C C_. (fig. 77), which is intended to give you a side view of the same piece. It must not be forgotten that the satisfactory performance of this firework depends mainly upon the exactness and true adjustment of the woodwork. Unless the revolving pieces are neatly hung, and the balance of the main framework is true, you must not expect success.

The coloured lights may be arranged as follows:—A green and a red light on one of the revolving pieces, and a purple and red on the other. These coloured lights are all to be connected together and with the mouths of the two extreme wheel-cases by quick-match. It will be obvious, then, that the coloured lights must be so prepared as to last during the combustion of the three driving cases.

The drawing at (fig. 78) represents a rather better position for the wheel-cases than that given at (fig. 76).

The diagram (fig. 79) represents a wheel frame, to which are attached at _f f f_ coloured lights. The position there indicated is a very good one for coloured lights when required for wheels of any such make as that in the drawing. You must not forget that they are all to be placed at _different distances from the centre of the wheel_. They may, of course, be made to play their part at any period of the wheel’s revolution. The coloured lights, for whose manufacture I have given directions above, are very valuable auxiliaries in nearly all exhibition pieces, and that we shall have occasion to call them in frequently to our aid as our practical pyrotechny becomes more advanced, and our enthusiasm in the art leads us to search for new combinations and effects.

TOURBILLONS—PLAIN AND BRILLIANT.

51. The tourbillon is a species of firework very ingeniously contrived to represent a spiral column of fire. Its performance is of short duration, but while it lasts it produces a very striking effect, and is, moreover, entirely different from any other pyrotechnic piece.

The preparation of tourbillons requires a considerable degree of nicety and precision, for unless the several proportions of the piece be accurately preserved, the true and intended effect will certainly be lost, and the operator not merely lose a feature, but a very beautiful feature, in his exhibition.

Since, then, it is utterly impossible to prepare successful tourbillons by careless manipulation, and to hurry over any part of their manufacture without some deterioration to their performance, I must beg that my readers will carefully follow my directions in every particular. They will then be able to make these tourbillons as successfully as I do. But if they prefer to work out some principle of their own, they must not hold me responsible for its results.

For the benefit of those of my readers who may know little or nothing of what a tourbillon is, I will first endeavour to explain the principle upon which it is constructed, and then give in detail the various operations necessary for its completion.

A tourbillon consists of a stout case filled with a strong sparkling composition, and closed very tightly at both ends. In this case are bored four holes, at which the fire is to find vent. Two of these holes are made underneath the case; from these the fire issues in a downward direction, and gives the piece the power of ascending perpendicularly. The other two holes are made in opposite sides of the case near each end; the fire issuing from these causes the case to revolve in a horizontal direction while it is ascending.

Now, it will be obvious that to gain an exact counterbalancing of these two forces considerable care and precision will be necessary. In order to make my directions as clear as possible, I intend to speak only of one size of tourbillon. You may make them of any size, from the 1-oz. up to the ½-lb. size, if you please; but you will find it by far the most _economical_ and _certain_ plan to keep to one effective size, and thus avoid all confusion and expense arising from the multiplication of tools and measurements.