Chapter V: Part 5

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.

Fig. 74.
]

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).

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.

Fig. 82.—Block to receive the tourbillon while it is being bored.
_m_—Groove in it to receive the quick-match. Fig. 83.—Block, with
settle (_n_) over which tourbillons are rammed. _Q Q Q Q_—Wooden
cylinder to enclose tourbillon case. _O O O O_—Iron rings to tighten
cylinder. _P P_—Pin to pass through cylinder, and settle to connect
them. Fig. 84.—Tourbillon complete, with stick attached. Fig.
85.—Revolving cradle from which tourbillons are fired. _s_—Iron
spike, with tubular top, in which the cradle revolves. Fig.
86.—Metal tourbillon scale.
]

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.

We must first of all know how to make the cases. These are to be _of the quarter-pound size_. You will derive little advantage from adopting a larger size than this, and you will find smaller sizes unworthy of such an exhibition as I trust you will be able to make by following my directions in these papers.

From each sheet of your 70-lb. brown paper you will only be able to cut two strips of sufficient width and length to make the ¼lb. tourbillon cases. These two strips are represented at _A_ and _B_ in the annexed diagram (fig. 80). _These strips must be eight inches wide._ Your sheets of paper measure about twenty-two inches on their short side; so that if _A_ and _B_ are eight inches wide, the remaining strip _C_ will be only _six_ inches wide, and useless, therefore, for tourbillon cases of our present size. But these spare strips are sure to prove useful for some purposes, and so no waste will be incurred.

Fig. 80.
]

The imperial board for these cases must be cut as in the adjoining illustration. Each sheet of board will provide four strips of a size proper for our purpose, each of which will be eight inches wide and fourteen inches long. Those marked _a_ _b_ _c_ _d_ are intended to represent the pieces to be used (fig. 81). Those marked _e_ _e_ should be kept with the spare strip marked _C_ in fig. 80, and will make you a good ¼lb. case for Chinese fire.

Fig. 81.
]

I will now suppose you to have divided your paper according to the above directions. In the next place you must paste both paper and board all over thoroughly. Brush some paste upon your ¼lb former (the one used for making rocket-cases, which is three-quarters of an inch in diameter), and then roll on your paper and board in the manner described at p. 77. Especial care must be taken that the innermost end of the strip of paper (that which lies next to the former) is so thoroughly saturated with paste that it cannot become separated or loose. If this precaution be not taken, some of the composition will, in the process of filling, drift behind it—will form a quick-match, as it were, inside your case, and will infallibly cause the tourbillon over which you have otherwise taken so much pains to vanish in a neat sharp report, and you will discover to your annoyance that in the place of a tourbillon you have only made an inferior kind of marroon.

Well, your cases are now made, and are eight inches in length, and three-quarters of an inch in their bore. Their external diameter will be found to be about one inch and an eighth.

We must next speak of the composition proper for filling tourbillons. For this purpose I employ the following formulæ, which I think will be found to answer well:—

No. 1.
FOR PLAIN
TOURBILLONS.
Nitre 8 parts.
Meal-powder 16 „
Sulphur 4 „
Charcoal 4 „

The charcoal that I use in making up this formula is the same that I recommended for rocket purposes—that is, it should be partly fine and partly coarse. If the above composition be found too strong, more charcoal may be added until the desired strength be gained.

No. 2.
FOR BRILLIANT TOURBILLONS.
Meal-powder 16 parts.
Nitre 8 „
Sulphur 3 to 4 „
Charcoal (fine) 3 „
Steel filings 6 „

The effect produced by this composition is very good indeed, and in my hands leaves nothing to be desired. It is advisable not to fill the cases with composition No. 2 longer than necessary before use, as the steel is sure to become corroded to some extent, and then much of the brilliancy of the sparks is lost.

Some pyrotechnists use _iron borings_ instead of steel filings for tourbillons. I cannot say that I have ever succeeded well with them. Iron particles will not work well in rapidly-revolving pieces, as far as my experience goes. They seem to me to become chilled too soon by their motion through the air, and produce hardly any scintillation. I, therefore, always use steel filings for all fireworks which are intended to revolve, and employ iron only in those that are stationary. Now, having prepared your composition, you will be ready to ram it into your cases. For this purpose you will require a simple piece of apparatus, which Mr. Newman will make for you at a small cost. You will find a drawing of it on my page of illustrations (fig. 83). It consists of a block of wood provided with a “settle,” on which one end of the tourbillon case is placed, and over which the composition is rammed. Then there is a wooden mould capable of inclosing the case and supporting it tightly and firmly while the operation of ramming is being performed. This mould consists of a hollow cylinder of wood pierced throughout, and of such a size in its bore as will just admit the tourbillon case. The mould is divided longitudinally in halves, and these halves are kept together by means of iron rings, which encircle the whole. You will find a full description given with the drawing.

In order to fill the cases, squeeze one end of one of them over the projecting piece at the top of the settle. Then fit on the two halves of the cylindrical mould, and drive down the iron rings until they are tight. The exterior of the cylinder is made to _taper_, in order that the rings may always fit tightly over it. And, lastly, put in the pin which secures the cylinder to the block and settle. You will now require a straight wooden drift, eight inches long (independently of its handle), and nearly three-quarters of an inch in diameter—one, in fact, that will pass _easily_ into your tourbillon case. The tools you have already—viz., a scoop for the composition, a mallet, and the short _solid_ drift which you used for driving in the clay over the composition in your quarter-pound rockets. First put into your tourbillon case as much clay as will, when rammed very hard, occupy _three-eighths of an inch in the length of the case_. The settle projects into the case about one-eighth of an inch, and thus half-an-inch at each end of the case is left for the purpose of insuring a very firm ending, which cannot be blown out by the combustion of the composition.

When the clay has been rammed in as tightly as possible, drive in the composition, a ladleful at a time, as uniformly as you can, until you have only half-an-inch at the upper end of the case unoccupied by it. Into this vacant space drive the same quantity of clay that you put into the lower end, and be sure that it is rammed in very firmly indeed.

The ramming of your tourbillon is now completed, but the most important part of its manufacture has yet to come. Open your penknife, and lay its blade on the table, back downwards and edge upwards. Place your filled tourbillon case across the edge of the knife, and _find the exact central point at which it balances on it, and mark that point by making a hole there with a small bradawl_. Now, having found the centre of its balance, you have next to mark the places at which the holes are to be made, and by far the best way to save yourself trouble in this respect, and to insure the proper marking out of all your tourbillons, is to follow my plan, which I am now about to describe. At fig. 86 I have drawn out for you a shape which you must get copied exactly in tin or zinc sheet. This piece of sheet metal, _when bent into the form of a trough of such a size as to fit tightly round your tourbillon case_, will give you the true position of the holes. In using it you will have to put the filled tourbillon case into it, and make pencil marks through the holes that correspond to those drawn in my sketch, and you will then have got over the entire difficulty. In the middle of the scale which I have drawn is one small hole marked _H_. _This hole is to come exactly over the mark which you made with your bradawl at the balancing point_, and if this be done all the rest must come right.

Having thus marked the position of the holes, the next thing is to bore them. They should be as nearly as possible three-sixteenths of an inch in size. I use a large bradawl for boring the holes, and it is better to drive it into the case with a mallet than to work it in with the hand. It must not be driven in farther than necessary, the object being merely to make a clear hole through the case, and not to disturb the composition. If you drive in the bradawl with your mallet you will require a small block of wood with a groove cut in it, in which you can lay the case while making the holes. I have given you a sketch of such a block at fig. 82. If it is two inches square or rather more it will be quite large enough. You will find the block very useful afterwards in attaching the stick to the tourbillon.

The plan that I have given for the _tin or zinc tourbillon scale_, as I shall call it, is drawn out _quarter size_, and the dimensions, marked, so that no tinman can have any difficulty in copying it accurately. Your tourbillon case is 8 inches in length. Half-an-inch at each end is taken up by the clay endings, so that you have seven inches of composition in the case. The two extreme holes, _which are on opposite sides of the case_, are made at the ends of the composition. The fire issuing from these gives the tourbillon a horizontal revolution round its centre of balance. The two inner holes, which are on the under side of the case, should be the same distance from one another that they are from the extreme holes. The fire issuing from these gives the tourbillon its ascending power.

But we have now to connect all these holes with quick-match, in order that the composition may take fire at all the four points simultaneously. To do this, begin at one of the under holes (those marked _F_ in the scale), and press into it the end of a piece of _uncased_ quick-match, taking care that the match reaches the composition. Then carry the match on to the nearest _side hole, and press it into it_. Then carry on the quick-match _over the upper side of the tourbillon_ to the side hole at the other end of the case, and press it in there; and, lastly, carry it on to the remaining under hole, and press it into it.

Having completed this operation, cut some strips of thin paper, about an inch wide, paste them well all over, and cover the quick-match with them, holes and all. A very little practice will enable you to adapt this pasted paper very neatly.

The tourbillon, if now ignited, will be sure to go somewhere, but probably not in the direction which we should like it to take. In order to regulate its flight we must do as we did with the rockets, adjust a stick to it, which shall have the effect of keeping its under side downwards, and so of compelling it to move upwards perpendicularly, if at all.

This stick is usually made of a curved shape in the manner represented at _I I_, in fig. 86. Those that I use I get from Mr. Darby; they are eight inches long, about an eighth of an inch thick, and are made of beech. There is a small hole in their centre through which a _flat_-headed nail is driven into the tourbillon at its balance point, which you marked with your bradawl. The stick must, of course, lie at right angles with the case in the manner represented at fig. 84. It is a very good plan to put a drop or two of glue at the point where the stick touches the case, as it will then be prevented from shifting its position.

In driving the nail through the stick into the tourbillon, make use of the block represented at fig. 82, having previously cut at the bottom of its rounded groove another small groove diagonally, so that when the tourbillon is lying upside down in the large groove, for the purpose of having the nail driven into it, the quick-match that extends across it may lie in the smaller groove, and may not be injured by being crushed, as would otherwise be the case.

The nails used should be about three-quarters of an inch long, and should have a smooth, flat head.

To fire the tourbillon, place it stick downwards on a level board, and see that it spins easily and freely on the head of the nail. Then with a portfire burn through the quick-match _in the middle on the upper side_. The tourbillon will make a few revolutions on the board before it begins to rise.

I have known several tourbillons fail, when I had reason to believe that there was nothing faulty in their make. They all behaved in the same unaccountable manner, jumping off the board and falling bottom upwards upon the ground. Of course, after this freak they could not right themselves. They appeared to sink into a kind of blustering, sulky fit, and when exhausted went out. Some time elapsed before I could assign any satisfactory cause for this remarkable behaviour, but at last I began to suspect the board on which the tourbillons were placed to fire them. It occurred to me that there was not room enough for the rush of fire from the under holes between the tourbillon and the board, that as soon as the fire had been conveyed to these under holes the force generated then and there was sufficient to throw the tourbillon over on its back, and thus effectually to prevent any further performance. Now this was by no means satisfactory, for if there is any single firework which requires care, exactness, and attention in its preparation, it is the tourbillon. I have often felt that I would much rather have a rocket than a tourbillon, for in the first place the latter takes much longer to make, and one feels that one should have some remuneration for one’s trouble; and in the next place a good tourbillon, though it is a species of firework not by any means so necessary to an exhibition as the rocket, is still one capable of producing a very unique and grand effect. I began to suspect that the board was the cause of my failure, and after a little consideration I came to the conclusions here enumerated:—

1st. That a board of proper size, shape, and level was a thing not always to be found when one wanted it, particularly if away from home.

2nd. That it was a very lumbering piece of luggage to carry with one when about to take an exhibition to a distance.

3rd. That, if warped by damp, or put out of its level in any way, it would be rather worse than useless.

4th. That something better might be contrived.

Whether I was right in blaming the poor board I do not know; but one thing is certain—that I have never, since the adoption of my new plan, had any failures at all with tourbillons.

I wanted something from which to fire the tourbillon which would leave it no excuse for turning on its back, which would be small and portable, and always ready for use.

I first made a brass cross of the shape and size indicated in fig. 87. In the ends of the arms I drilled holes, into which I soldered pieces of stout brass wire about two inches and a-half long. Thus a sort of cradle was formed like that which is represented at fig. 85 in the plate. The next thing to be done was to enable the cradle to revolve very easily. To do this I soldered on to the centre of the under side of the cross a piece of brass rod of the size generally used for stair-rods. This piece was about six inches in length, and was filed at its lower extremity to a point on which it might revolve. I thus had made a thing like that in fig. 88. Now all that I had to do was to get a piece of glass tubing, into which my piece of rod at _a a_ would fit easily, and in which it would turn freely. This I did, and procured also a piece of iron rod half-an-inch in diameter and about eighteen inches long. I had this forged into a kind of spike point at its lower end, and filed at its other end, to pass about an inch into the brass tube, and then I had the tube and iron spike soldered together. This iron spike I press into the ground, taking care that it is upright, and then drop the brass rod which is soldered to the cradle into the brass tube at the top of the spike. The cradle will be found to revolve freely. In it I lay the tourbillon, with its stick downwards. When it is fired the holes at its _sides_ are first ignited, and so its _horizontal_ revolutions begin before any ascending power is given to it. The cradle of course revolves with it, and, if properly made, can offer no obstruction of any kind to its free play. But as soon as the fire is communicated to the _lower_ holes, the force there developed will lift the tourbillon out of the cradle, and will send it on its upward flight.

My description of this little piece of apparatus may, perhaps, incline my readers to imagine that its manufacture is difficult. I can only assure them that it is not so, and that, if they will only give it a trial, they will be convinced of the advantages which it possesses over the old plan of the board. Probably some modification of its principle will occur to you which may render it still more easy to be made. The means at your own command are, after all, the best referees as to which is the shortest and readiest method of carrying out any plan. I have given you the method by which I obviated the difficulty that met me. I need only add that if you use the board I hope that your tourbillons will not disappoint you as mine did me.

Many persons make _six_ holes in their tourbillons—four on the under side, and one at each end or opposite side. For my own part, I never could see the advantage of this plan. I have tried it and succeeded with it, but the effect has been always to convince me more firmly of the superiority of the four-hole system. I know one or two very successful pyrotechnists whose experiments have led them to the same conclusion.

It is possible to ram tourbillons without a cylindrical mould, but it is neither advisable nor convenient. The cases require some very substantial support while they are being filled, for the composition cannot easily be driven too hard. The cylindrical mould cannot be an expensive apparatus if made as I have suggested. Mr. Newman has such facilities for boring blocks of wood and turning them, that I strongly recommend you to get him to make you one, as it will considerably lighten the trouble of preparing tourbillons, besides giving them, when prepared, a much better chance of success.

I beg here to give my readers the size of 70-lb. paper and imperial board, that there may be no difficulty in knowing what to purchase. The sheets of 70-lb. brown paper and imperial board are of precisely the same size, which is 22½ × 29 inches.

I must conclude the subject of tourbillons with one hint. The person who fires a tourbillon with a portfire will generally fail to get a good view of its performance. The plan that I commonly adopt is to cut an inch of quick-match and twist some touch-paper round one end of it, and lay the other end next to the match on the tourbillon at the point _r_ in fig. 84, pasting a piece of thin paper over it to secure it, and leaving its other end free, with the touch-paper round it.

COLOURED FIRES.

52. _Coloured fires_, such as are employed for illuminating gardens, shrubberies, avenues, buildings, &c., will now occupy our attention.

Fig. 90.—Former for Coloured Fire Cases.

Fig. 91.—Iron Fork to support Coloured Fires while burning.
]

This species of firework is of very simple construction, and requires only an ordinary amount of care in order to insure its success. And it is very fortunate that so necessary an item in the programme of a pyrotechnic display is one which can be relied upon for producing so beautiful and surprising an effect. I have known spectators more pleased with the coloured fires in an exhibition than with any other of its features; and I am convinced, that by a well-contrived introduction and arrangement of them, results may be produced at least as effective and satisfactory as by any combination of a much more elaborate character.

But before entering upon the description of their manufacture, it will be necessary for me to remind you of some information that I have already given in the portion devoted to coloured stars, in order that you may be induced not to prepare your colours for an exhibition until you know _what you are going to prepare them for_—that is, what sort of a place they are required to light up.

What I have before said under the head of Coloured _Stars_ with regard to the illuminating or reflective properties of this or that composition, must more than ever be borne in mind in the matter of coloured _fires_. There are two kinds of fires used in pyrotechny—one burning with a considerable depth and richness of tint, but possessing a very moderate illuminating power, the other having great brilliancy and reflective power, but not the same depth of colour. Now with this plain distinction before us, there will be no difficulty in selecting such composition as will produce the desired effect. You have simply to make up your mind beforehand whether you require a colour of considerable intensity, _which you may gaze at while it burns_, or one whose beauty will be seen to advantage, _not in itself_, but in its reflection upon those objects which are within reach of its illumination.

The formulas which I shall give will be characterised as “reflective,” or “intense in colour,” and if they are only made up with pure, dry, and fine ingredients, will, I am sure, give as good results as need be desired.

In the first place the preparation of the cases is to be considered. With regard to these it must be remembered that they are required _to burn with the composition_, and must not be made too thick or hard on that account. The thicker they are, the more will their consumption interfere with the burning of, and impair the colour produced by, the composition. A sheet of 60lb. or 70-lb. brown paper cut up into nine strips in the manner represented at fig. 89 will furnish you some very good cases for the purpose. Each of these strips will be a little over three inches in width, which, in my opinion, is quite sufficient. The former for these cases is made of wood, and should be from an inch and a-half to an inch and three-quarters in diameter, and about four inches long, irrespectively of its handle. The drift for filling the cases may be of the same length, and _one-sixteenth of an inch smaller in diameter_, so as to admit of its passing easily in and out of the case.

Fig. 89.
]

The difficulty that I have always experienced with regard to these cases has been this—they must be made of a certain thickness, in order that they may not be broken during the process of ramming in the composition. This process is, I believe, indispensable. At all events, I find it so, for _if the composition be only pressed in loosely, and not rammed, it will fall to the ground in burning lumps_, instead of burning slowly and evenly in and with its case; and if the cases be made unnecessarily thick, either the composition will not burn freely enough, or its colour will be impaired (and this will be particularly the case with regard to _green_ fires), or, what is more probable still, both these calamities will happen at once, and render your production doubly ineffective.

Now my plan for obviating the difficulty has been to increase the _diameter_ of the cases, and thereby to gain a greater body of composition in proportion to their _thickness_. This plan I have found to answer very well, and so I can conscientiously recommend it to you.

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).