Part 9

I must next suppose you to have three cases of the 1-oz. size ready filled and primed and papered. Before fastening these on your framework _take especial care that the one which is to burn last has its end stopped up with some incombustible material_. The best plan is to ram some powdered clay upon the composition before removing the case from the nipple, in the same manner as recommended for the ends of rockets. If some precaution of this kind be not taken, the fire issuing from the mouth of the first of your three cases will be communicated to the tail of the third, and thus bring your wheel to a most inglorious end.

Having, then, taken this precaution, proceed to tie on your cases to the edge of your wooden framework. This is easily done if you bore two holes, through which your string can pass, close to each of those sides of the frame on which the cases are to lie. A reference to the sketch of the framework (fig. 59) will show you where these holes should be made.

In tying on your cases, be quite sure that the mouths or choked ends of them lie all in the same direction, in such a manner that the tail of the first case reaches almost to the mouth of the second; the tail of the second to the mouth of the third; the tail of the third to the mouth of the first. When you have secured them firmly in their places with string, you can then proceed to connect them with quick-match—or _clothe_ them, as it is called—so that when one case is burned out it will communicate its fire to the mouth of the next, and so on till they are all consumed.

In cutting your quick-match, bear in mind that about an inch of the black match itself must project uncovered beyond each end of the paper tubes in which it burns. This is to insure its taking and communicating its fire. In the annexed sketch (fig. 63) you will see represented a piece of quick-match as it should be cut for connecting cases. At fig. 64 is represented a wheel-case, such as is to burn second in your single triangle, and has a piece of quick-match, like fig. 63, at each of its ends, to connect it with the first and third case on the wheel. You will observe that the newspaper which projected beyond the ends of the case is simply tied in tightly round the quick-match. You will, after a few trials, be able to get through this “clothing” operation very easily, and with no unnecessary wasting of quick-match.

The mouth of your first case may either be finished off with touch-paper, or may have a short piece of quick-match put into it, to be lighted with a portfire.

Your wheel is now completed and ready for firing. But I may as well suggest here that its beauty and effectiveness will be very much enhanced if the three cases on it be filled with different compositions. For instance, fill the case _which is to burn first_ with composition No. 2; that which is to burn second with No. 4; and the third case with No. 1. This plan of varying the compositions, or any other that suggests itself, may be adopted in the case of _all_ wheels. It is necessary, however, that you should be well acquainted with the character of each composition, in order that you may be able to produce the exact effect that you require at the right time.

Composition No. 1 gives only brilliant sparks, and must be prepared as shortly as possible before use.

Composition No. 2 will give a whitish circle of fire fringed with red sparks.

Composition No. 3 produces less white flame and more sparks than No. 2.

No. 4 is a sparkling composition; by far the best for general use, in my opinion.

No. 5 gives reddish sparks, which fly off in very straight lines from the wheel, and form rays, as it were.

No. 6 gives rays, brilliant sparks, and a centre circle of white fire.

No. 7 gives a moderately good centre, with drossy red sparks of a peculiar shape.

Those compositions which throw out the greatest number of sparks during combustion are the best for larger wheels, but will be found also very effective in the common single triangle.

Those which have a tendency to produce a _flame_, rather than a _jet of sparks_, are very effective as a variety for _small_ wheels, but produce an effect comparatively poor when employed for those of greater dimensions.

For _horizontal_ wheels, _sparkling_ compositions alone are effective, because in them everything depends upon the form that the fire assumes _in its outline_, and not upon the shape of the wheel itself. Compositions which produce but few sparks would be entirely out of place if used to turn horizontal wheels.

DOUBLE TRIANGLE WHEELS.

46. I will now offer a few remarks with respect to the construction of the _Double Triangle Wheel_. This piece may be made by employing two hexagonal frames of wood of the same size, in a centre twice as long as that described in fig. 60. But it may also be made in such a framework as Mr. Darby will supply, which is a nave made of light wood, with six spokes, cut at their ends in such a manner as will allow the cases to be firmly attached. But whether you use the one form or the other, the principle is precisely the same, and the cases must be arranged as shown in the adjoining diagram (fig. 65).

The performance of this wheel is, of course, the same as that of the single triangle wheel, and differs from it only in the matter of duration. But it must be borne in mind that a double triangle wheel, having six cases upon it, would be a very slow sample of pyrotechnic beauty _if all these cases were filled with the same composition_. It would, indeed, be a most meaningless performance. You must therefore take care that some variation is made, using at least two varieties of composition. You will then have an effective piece, capable of lasting a long time in proportion to its size.

VERTICAL WHEELS.

47. Leaving now the triangular form of wheels, we will pass on to those which are called _Vertical_. All triangle wheels are vertical wheels, but all vertical wheels are not triangular; it is of non-triangular vertical wheels that I am now about to speak. These are made with a nave, spokes, and felloe in the same manner as a carriage wheel. The cases may be fastened to the felloe, or the wheel may be made without a felloe, and the cases fastened, in any way that occurs to you, to the extremities of the spokes; either by nailing to their ends pieces of wood at right angles with the spokes, or by cutting a groove in the end of each spoke and tying a case into it with string. As long as the cases be properly arranged and secured firmly to the framework it matters very little which of the above plans is adopted. Select the plan which can most easily be carried out by the means that you have at command, and carry it out in the simplest possible way. Complications are not only unnecessary, but very likely to deprive your pieces of what would otherwise have been their complete success. The accompanying sketch (fig. 66) gives you a representation of another arrangement of six cases, which is, in my opinion, productive of a better effect than the double triangle. The wheel here represented is vastly improved by the addition of a coloured fire placed somewhere near its centre; but I have not yet given any directions or instructions for the preparation of colours for such a purpose, and the making of these additions must be reserved for its proper place.

But perhaps the most satisfactory arrangement of six cases on a vertical wheel is that which the next sketch represents. By the plan adopted there—_that of making the cases incline outwards_—a much larger circle of fire is produced, and the general effect is considerably improved. It will be perceived that the mode of “clothing,” and tying on the cases, for all these different forms of wheels is the same, the only difference being in the shape of the framework. The cases may be fired singly or doubly in this wheel—that is, you may make them burn one at a time till all are consumed by putting the quick-match to them just as my sketch (fig. 67) represents, or you may connect with quick-match the first and fourth cases, so that these take fire simultaneously. By this arrangement the first and fourth cases will work together, the second and fifth, and the third and sixth. Of course the first and fourth cases are the only _pair_ that need be connected by quick-match, for they will severally convey their fire to the second and fifth, and these to the third and sixth. The framework of this wheel may be made of deal or beech (the latter I should prefer) about three-eighths of an inch thick; the wheel altogether should be from 15 to 18 inches in diameter. It should by all means have some centre, like that described at fig. 60, to secure its steady and true movement. This wheel also will be vastly improved by the addition of a coloured fire to its centre.

We will now proceed to speak of

HORIZONTAL WHEELS.

48. These, like the vertical wheels, may be made of almost any shape or design. They have a hole bored in the exact centre of their nave, and up this hole the spindle passes on which they revolve.

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

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

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

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

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

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

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

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

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

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

LANCES—WHITE AND COLOURED.

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

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

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

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

COMPOSITIONS FOR LANCES.

_White._

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

Or,

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

Or,

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

Or,

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

Or,

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

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

_Yellow._

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

Or,

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

_Green._

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

Or,

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

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

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

Or,

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

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

_Red Lances._

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

Or,

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

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

_Rose-coloured Lances._

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

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

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

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

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

Or,

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

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

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

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

Or,

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

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