Part 12

Take, then, one of the strips of paper, cut as recommended above, and, pasting it all over on one side, roll it evenly round your former, having previously brushed a little paste over the former to prevent the paper sticking to it. Having rolled the strip up evenly and smoothly, take it off from the former, and set it by to dry. It will readily be perceived that these cases are among the easiest to make.

And now we may pass on to the important subject of the compositions with which these cases are to be filled.

The first of these is known as the:—

COMMON BENGAL LIGHT.

53. It has a bluish-white colour, and is called by some pyrotechnists “Artificial Moonlight.” Its composition is:—

No. 1. Nitre 12 parts. Sulphur 4 „ Antimony 1 part.

Orpiment or realgar may be substituted for the antimony, in which case there will be less smoke.

The above is the commonest sort of Bengal light. It gives a pretty effect, but has no great illuminating power.

54. WHITE FIRE.

WHITE FIRE. No. 2. Nitre 32 parts. Sulphur 8 „ Regulus of antimony 12 „ Red lead 11 „

This is a French composition, introduced by Chertier, and is remarkable for its whiteness. It will be found a very useful composition, possessing a fair reflective power.

WHITE FIRE. No. 3. Nitre 24 parts. Sulphur 7 „ Realgar 2 to 3 „ Antimony 1 part.

This I always find the most serviceable composition on the whole. It does not possess the intense whiteness of No. 2, but has a slight tint of blue; and this difference alone would gain it the preference in my judgment. But it has also a greater illuminating power, and is decidedly the best composition that I have yet been able to find.

The red lead recommended in composition No. 2 can be purchased in fine powder, ready for use, at any painter’s or chemist’s shop.

YELLOW FIRE.

55. We may now proceed to the formula for—

YELLOW FIRE. No. 4. Nitrate of baryta 36 parts. Oxalate of soda 6 „ Sulphur 3 „ Shellac 5 „

This composition produces a good colour and has a moderate reflective power. Its principal merit lies in the fact that it will keep good for any length of time after it is mixed, and can be made with samples of nitrate of baryta which will not produce a good green.

YELLOW FIRE. No. 5. Nitrate of soda 48 parts. Sulphur 16 „ Antimony 4 „ Charcoal (fine) 1 part.

This is decidedly the best formula for yellow fires, as far as effect is concerned. But the nitrate of soda is so highly deliquescent that the composition must on no account be made up longer before use than is absolutely necessary. Yellow fires are not much used in pyrotechnic exhibitions. I suppose this is to be accounted for by the extraordinary power that they possess of giving to all objects, especially the human face, a ghastly and death-like appearance, anything but agreeable to behold. I have no doubt, however, that some of my younger readers, knowing this, will set a higher value upon the formulas for yellow fire, for the fun of showing off the spectators of their exhibitions to the greatest possible disadvantage. Especial notice should be taken of the complete annihilation of colour in flowers, dresses, &c., by this yellow light. The effect is, of course, very similar to that produced by the burning of spirits of wine or naptha holding salt in solution. This latter is known as the _monochromatic light_; that is, a light in which only one of the colours of the spectrum is shown.

Although I do not remember ever having seen a yellow fire used in any large exhibition of fireworks, I have given the above formulas in order to render my paper upon the subject as complete as possible.

The next colour with which we shall deal will be the

GREEN FIRE.

56. For this colour I shall give three formulas, all of which I have found good, notwithstanding the universally acknowledged difficulty of obtaining a real green colour. This difficulty has arisen, I believe, solely from the imperfections and impurities in the nitrate of baryta which finds its way into the market. This salt should be prepared from the sulphate of baryta, _and not from the carbonate_; and I think I am right in stating that it is far more generally prepared from the carbonate than from the sulphate. When this is the case you either get a very decent _yellow_ colour from the sample, or you get a salt which burns about as green as a very bad specimen of nitre will burn. My readers will readily understand that nitre ought not to be so green as to admit of this.

And now, before giving the formulas, it only remains for me to say that if you have but a really good sample of _dry_ nitrate of baryta _in fine powder_, you ought to be able to make from the following receipts a green fire which will answer any purpose:—

GREEN FIRE. No. 6. Nitrate of baryta 45 parts. Chlorate of potash 10 „ Sulphur 10 „ Antimony (sulphide) 1 part.

The above formula gives a pure but pale green. It has a most intense illuminating power, and for this cause is very valuable. The addition of a little nitrate of baryta will render the composition more intense in colour, but will detract from its rapidity of combustion, and therefore from its illuminative power.

No. 7. Nitrate of baryta 77 parts. Chlorate of potash 5 „ Sulphur 12 „ Charcoal 2 „ Orpiment or realgar 2 „ Shellac 2 „

Composition No. 7 is a very old one, slightly altered to make it burn more freely. It gives a more intensely green colour than No. 6, but has not the same advantage with regard to its illuminative properties. It is, however, a very serviceable and inexpensive receipt to employ.

We now come to the best of all the formulas for green fire that I have been able to meet with, and one which has thoroughly satisfied me. It is almost the same as that recommended by Chertier, the difference consisting in a slight decrease in the quantity of calomel, which enables the composition to burn rather more freely and adds to its reflective power. I have seen a real emerald green produced by this composition when good nitrate of baryta has been used, but in this, as in the case of all other green fires, if you do not succeed you may generally fasten your suspicions upon the nitrate of baryta.

No. 8. Nitrate of baryta 40 parts. Chlorate of potash 4 „ Sulphur 8 „ Calomel 8 „ Charcoal (fine) 2 „ Shellac 1 part.

I do not think that any better formula than this can be needed. It carries with it a better combination of intensity of colour with intensity of illuminating power than any coloured fire composition that I am acquainted with.

PURPLE FIRE.

57. I have next a formula to offer which I think has considerable merits of its own. It produces a purple colour of a very pleasing tint, and has also very considerable illuminating power. I have never seen a colour of this kind employed in any pyrotechnic exhibition, but I believe it to be an effective composition, and one certainly that will make a change from the ordinary routine of white, green, and red. I shall dignify it by the title of—

PURPLE FIRE. No. 9. Nitre 48 parts. Sulphide of copper 12 „ Sulphur 12 „ Calomel 6 „ Arsenic 6 „ Nitrate of strontia 6 „ Chlorate of potash 4 „ Shellac 4 „ Charcoal (fine) 1 part.

I trust that my readers will not be alarmed at the number of ingredients in the above formula. I can only promise them that the colour produced is an extraordinary one, and cannot be produced by ordinary means. You will observe that I have recommended 12 parts of sulphide of copper. This must be the _fused_ sulphide. Or you may substitute for it equal parts of Chertier’s copper and sulphide of copper, or equal parts of Chertier’s, or of sulphide of copper and fine black oxide of copper. The _arsenic_ employed in the formula may be either orpiment or realgar, but by far the best preparation of arsenic for this purpose is the _finely powdered metallic arsenic_. Formula No. 9 is one of my own introduction. It possesses the advantages of being perfectly safe, deep-tinted, and decidedly illuminative. But I do not pretend to say that it can ever be admired to the same extent with the red and the green fires. These latter will always take the precedence, for their effect at night is so thoroughly theatrical and surprising that no other colour, however beautiful or extraordinary, can hope to supersede them. I was once asked by a lady to make a _brown-coloured_ flame. The idea was so rich in theory that I never attempted to dissolve its charm by any failures in experimental practice. But had I succeeded to the utmost with this brown fire, no illuminating properties could ever have been obtained. One might as well have expected a good effect from a _black star_ or a _neutral tinted sun_.

RED FIRE.

58. We come now to the most telling colour of all—the red, or crimson as it is usually called. In the preparation of the _green_ fires the _purity_ of the nitrate of baryta is the most important consideration. In that of the red fires the _dryness_ of the strontia is the main point. This is most especially to be borne in mind, as success or failure depends upon it. A really good red-coloured fire is often the making of an exhibition or its redeeming point, but in any case it is a most important feature, and on that account is worth the expenditure of any trouble on its preparation.

I shall give several formulas for red fires, each having its own characteristic properties. You will have but to determine the particular description of fire that is necessary, and I think you will find all that you need among the following compositions:—

RED FIRE. No. 10. Nitrate of strontia 20 parts. Chlorate of potash 3 „ Sulphur 5 „ Antimony 2 „ Charcoal (fine) 1 part.

This formula gives rather a deep rose-coloured flame, and has a most intense illuminating power. But the composition is one on which the non-dryness of the nitrate of strontia has the most disastrous effects. It is, when properly prepared, a very useful composition for illuminating buildings, &c., &c.

The next is a slower composition, having decidedly more intensity of colour. It is a remarkably good composition, having considerable depth of tint, and a very fair amount of reflective power. Its proportions are these:—

No. 11. Nitrate of strontia 64 parts. Chlorate of potash 4 „ Charcoal (fine) 5 „ Sulphur 24 „

The next formula is one of very slow combustion, but of the greatest depth of colour. It has but a small illuminating power, and can therefore be employed only for certain purposes.

No. 12. Nitrate of strontia 48 parts. Chlorate of potash 4 „ Sulphur 12 „ Calomel 8 „ Chertier’s copper 2 „ Charcoal (fine) 1 part.

This composition, burns so slowly that if it be very much compressed, or its case be at all thick, much of its effect is lost. I should therefore recommend that it be laid in a heap upon a tile in order to be fired. Its beauty will then be seen to the greatest advantage.

The following composition for red fire is the one which I have always found the most generally useful:—

No. 13. Nitrate of strontia 70 parts. Chlorate of potash 6 „ Sulphur 24 „ Charcoal (fine) 2 „ Shellac 2 „

This composition, when employed in a case 1¾ inch in diameter, produces a magnificent effect, and is at the same time a very economical composition to make up. Its combustion does not appear rapid, and yet there seems to be no lack of illuminating power combined with intensity of colour. It is, of all the compositions which I give, the one best adapted for the use of young aspiring pyrotechnists, as very certain in its results, very inexpensive, and very easy to prepare.

Thus we are brought to the close of our list of compositions for Coloured Bengal Fires. I trust that this list will be found to contain all that you require, and contain it, too, in variety and abundance.

But we have still to consider how these compositions are to be encased and fired.

COLOURED FIRES (To Encase).

59. The cases, made as directed above, I will now suppose to be dry and ready for use. Your drift, with which the composition is to be compressed into the cases, is one-sixteenth of an inch smaller in diameter than your former. It will therefore pass easily within the cases which were made upon “the former.” Now cut some pieces of newspaper, or thin brown paper, into squares or circles about 3 inches in diameter. Place the flat end of your drift in the centre of these, and turn down the papers round its sides in the same way that papers or bladders are turned down over bottles or jars when these are to be capped or covered. Then insert the drift with the paper cap over it into one end of the coloured fire case and push it through to the other end. Now withdraw the drift, and leave the paper cap in the end of the coloured fire case. Next place the case upright upon your driving-block with the end, thus filled up, downwards, and put into it as much powdered clay as will, when driven, occupy about half-an-inch in the end of the case. Drive this clay down firmly with a few blows of the mallet, taking care, however, not to rupture the case by exerting too great a force.

The case is now ready to be filled with composition. This operation is to be done as follows:—First put in enough of the composition to occupy about half-an-inch in the case, and ram this down with a few light blows of the mallet. Then put in another quantity, and ram that down in the same way; and so on till the case is filled. I strongly recommend you not to put in more composition at a time than will ram down into the space of half-an-inch. You will find it easy to compress the whole of the composition equally and uniformly by attending to this simple piece of advice; and you will soon discover, if you do not already know, the advantage of uniform compression.

When you have charged the case as far as you can with the drift and mallet, that is, to about a quarter of an inch from the top of the case, press the mouth of the case into the composition (from which you were filling it) until the case becomes full up to the brim. Over the flat surface of composition thus left, paste a piece of touch-paper, or any thin paper, taking care not to paste that part of the paper which lies against the composition, but only that which is to stick to the sides of the case.

COLOURED FIRES (To Fire).

60. Your coloured fire is now complete and ready for firing. This is the usual and most convenient way of preparing colours for exhibitions. But for your own experiments you may place a small quantity of the composition to be tried upon a tile or brick, not spreading it about, but piling it into a pyramidal heap, to be lighted at the top. Many persons adopt this plan for exhibitions, but it is not good, because several of the best compositions burn too rapidly when unconfined by a case. I only beg that you will do me the justice to remember that the formulas which I have given above are intended to furnish compositions suitable for burning in such cases as I have described, and not, as a general rule, adapted for open and loose burning. My plan all along has been this—to find compositions of sufficient freedom of combustion to enable them to consume their case, to give a powerful light, and not to burn out too rapidly. I think I have succeeded in gaining the first two of these qualities in the compositions themselves, and the third by compressing them closely in cases.

It is very much better to put into each case two different sorts or colours of fire, making the fire, for instance, change from white to red, or from green to purple. But if this be done, and more than one case is to be burning at a time, of course an especial regard must be had to the contrast of colour. You should never burn a yellow with a red fire, or a yellow with a white; green with red, yellow with purple, white with red make the best contrasts.

But, for my own part, I never burn two Bengal fires of different colours at once. If the fires have any illuminative power at all, they are pretty certain to neutralise one another’s effect, and so give you a very poor and unsatisfactory return for your outlay. It is very true that red and green are _complementary_ colours, as they are called, and look very well side by side, but the effect produced upon an object by illuminating it with a red and green light is anything but complementary to the object or to the coloured fires themselves. If you wish, however, to try the effect of the contrast, use compositions possessing the greatest depth of colour and the least reflective power; in this case the fires themselves will be complementary one to another, and their non-illuminative properties will effectually prevent any confusion of reflection. That what I have said above is true any one may discover by getting two pieces of stained glass, one of a rich red, the other of a rich green colour. Let these colours be thoroughly _transparent_, and if you place one before the other and attempt to look through them, you will find that you have a medium through which very little can be seen at all.

The cases of coloured fire, made as directed above, must not be placed perpendicularly to be fired, but _horizontally_. The reason of this is very simple. While they are burning a sort of boiling lava is formed, which is the refuse of the combustion, and this will considerably clog the flame and rob it of much of its light if allowed to remain at the mouth of the case. Now if the cases be placed horizontally, this lava will fall away as it forms, and leave the fire to burn without impediment.

All that it is necessary to do to give the cases this horizontal position is to drive two long, stout nails into a post horizontally, about an inch and a-half apart, and lay the case on these. Coloured fires should, as a general rule, be fired at a distance of about three or four feet from the ground.

But as one cannot always find nails of the proper sort for these purposes, especially when at a distance from one’s own stores, I have sketched for you an iron which I always use, fig. 91, and which I am sure you will find convenient. It is made in the shape of a tuning-fork, with a screw at its handle; this screw is simply twisted into a gimlet-hole in a post, and is easily put up or removed.

I must not omit to say a few words with regard to the placing of coloured fires. This must depend mainly upon individual taste, but a few hints may not be out of place. I cannot help thinking that the best and most effective way of displaying coloured fires is _to conceal the fire itself, and let only its illumination or reflection be seen_. Let any of my readers keep his spectators at a distance of twenty or thirty yards from the coloured fire, and hold up a tray or piece of board in front of the fire, of such a size as will conceal only the fire itself. I think it will be generally admitted that the beauty of the piece is much enhanced by this simple contrivance, and if it be thought so, then it becomes a consideration whether it would not be better to use the most illuminative colours always out of sight, in such a position that their effect only can be seen. For instance, if there be a large tree conveniently at hand, place your colour on that side of it which is away from the spectators, so that the trunk of the tree is between them and the coloured fire. This plan I have always found to give a most charming result.

But it must be remembered that anything but highly illuminative colours cannot be employed in this manner. You will of course find objectors to the plan mentioned above. There are many people who will tell you, “No, I like to see the light itself,” as if gazing on the sun or moon, except for astronomical purposes, could ever give half the pleasure that the sight of a fine sunlit or moonlit landscape can impart.

What would a fairy scene in a pantomime be worth if you saw some of the green-room myrmidons, with a pot of beer in one hand and a lucifer-match in the other, lighting a heap of composition on a tile beside the stage, and then saw the composition burst into a smoky flame, but were prevented from seeing the effects of its colour?

This suggests to me another branch of my present subject, which some of my readers may consider an important one.

COLOURED FIRES FOR THEATRICAL PURPOSES.

61. In the event of private theatricals you may not, or your friends may not, like their drawing-room to be filled with a strong sulphurous smoke, which is pretty certain to hang about the drapery of the room and the dresses of the company for some unpleasantly long time. I shall therefore give you now two or three formulas for coloured fires which may be safely used in a room, and which contain no sulphur.

But first let me give you this caution, which it is most highly important that you should attend to:—

NEVER BURN ANY COLOURED FIRE COMPOSITION INDOORS, OR IN ANY INCLOSED SPACE, WHICH CONTAINS ORPIMENT, REALGAR, OR ANY PREPARATION OF ARSENIC AMONGST ITS INGREDIENTS. THE FUMES FROM SUCH COMPOSITIONS MUST BE VERY INJURIOUS. THEY CAN ONLY BE USED WITH SAFETY OUT-OF-DOORS.

COLOURED FIRES FOR THEATRICAL PURPOSES. WHITE. No. 14. Chlorate of potash 12 parts. Nitre 4 „ Sugar 4 „ Stearine 1 part. Carbonate of baryta 1 „

This does not give a pure white light, for it is impossible to get a real white without sulphur, but when used to overpower theatrical lamplight, it is to all intents and purposes white.

YELLOW FIRE. No. 15. Chlorate of potash 6 parts. Nitre 6 „ Oxalate of soda 5 „ Shellac 3 „