CHAPTER X.
OF THE MANNER OF FIXING AND ARRANGING FIRE-WORKS IN GENERAL FOR EXHIBITION.
Having already treated of the formation of various kinds of fire-works, we come now to consider their arrangement in fixed and moveable pieces.
It is obvious, that the order of arrangement, the manner of disposing the work, or establishing pieces for exhibition, may be greatly varied according to taste and fancy. The great variety of fixed and moveable pieces, consisting of suns, moons, stars, &c. which may be either made permanent, or to revolve on, or round a centre; or of wheels, double, single, or treble, either moving round other wheels, or by themselves in a vertical or horizontal order, together with the arrangement of fire-pots, and coloured lights, the management of rockets, the formation of aerial stars, serpents, tourbillons, &c. and the imitation of cascades, girandoles, and water-falls, all depend on the taste and fancy of the artist.
It is our intention, therefore, in the different sections of this chapter, to give the order and arrangement of pieces, as adopted in Europe, and particularly in France; so that the manner of fixing any one piece, or combination of pieces, to produce effects of different kinds, may be seen at one view. The moveable pieces are generally made of wheel-work, the wheel always turning upon an axle, which may pass entirely through and be kept on by a nut or pin. They should revolve without much friction, and, for this reason, the spindle should be of metal, and oiled or greased. Black lead, along with tallow, will diminish the friction very considerably. As to the formation of the wheel, whether it be solid, or formed of spokes and a band or hoop, or made with several concentric bands, placed at given distances apart, &c. the observations on this head will be found under the respective articles, and, generally, on all other pieces for exhibition.
We purpose, in a subsequent chapter, to notice particularly the works, made in and on water, usually denominated _aquatic fire-works_; as their arrangement, in many respects, differs from those on the land. Aquatic works furnish a variety, both in character and effect, and, therefore, are calculated to produce, in conjunction with land works, a brilliant spectacle. Of this, we have an instance, mentioned in the introduction to this part of our work, in the splendid exhibition at the _Pont Neuf_ in Paris.
_Sec. I. Of the Composition of Wheel-Cases, standing and fixed._
It may not be improper, before noticing the arrangement of wheel-cases, to give in this place the compositions, which are used for charging them, reserving, however, the notice of some preparations, when we treat of such works, in which they are particularly employed.
_Wheel-cases from two ounces to four pounds._
1. Meal-powder, 2 lbs. Saltpetre, 4 oz. Iron-filings, 7 --
2. Meal-powder, 2 lbs. Saltpetre, 12 oz. Sulphur, 4 -- Steel-dust, 3 --
3. Meal-powder, 4 lbs. Saltpetre, 1 -- Sulphur, 8 oz. Charcoal, 4½ --
4. Meal-powder, 8 oz. Saltpetre, 4 -- Sawdust, 1½ -- Sea-coal, ¾ --
5. Meal powder, 1 lb. 4 oz. Sulphur, 4 -- 10 dr. Saltpetre, 8 -- Glass-dust, 2½ --
6. Meal-powder, 12 oz. Charcoal, 1 -- Sawdust, ½ --
7. Saltpetre, 1 lb. 9 oz. Sulphur, 4 -- Charcoal, 4½ --
8. Meal-powder, 2 lbs. Saltpetre, 1 -- Sulphur, ½ -- Sea-coal, 2 oz.
9. Saltpetre, 2 lbs. Sulphur, 1 -- Meal-powder, 4 -- Glass-dust, 4 oz.
10. Meal-powder, 1 lb. Saltpetre, 2 oz. Steel-dust, 3½ --
11. Meal-powder, 2 lbs. Steel-dust 2½ oz. Beat iron, 2½ --
12. Saltpetre, 2 lbs. 13 oz. Sulphur 8 -- Charcoal, 4 --
_Slow fire for wheels._
1. Saltpetre, 4 oz. Sulphur, 2 -- Meal-powder, 1½ --
2. Saltpetre, 4 oz. Sulphur, 1 -- Antimony, 1 -- 6 dr.
3. Saltpetre 4½ oz. Sulphur, 1 -- Meal-powder, 1½ --
_Dead fire for wheels._
1. Saltpetre, 1¼ oz. Sulphur, ¼ -- Lapis calaminaris, (prepared calamine,) ¼ -- Antimony, 2 dr.
_Standing, or fixed cases._
1. Meal-powder, 4 lbs. Saltpetre, 2 lbs. Sulphur and charcoal, (together,) 1 --
2. Meal-powder, 2 lbs. Saltpetre, 1 -- Steel-dust, 8 oz.
3. Meal-powder, 1 lb. 4 oz. Charcoal, 4 oz.
4. Meal-powder, 1 lb. Steel-dust, 4 oz.
5. Meal-powder, 2½ lbs. Sulphur, 4 oz. Seacoal, 6 --
6. Meal-powder, 3 lbs. Charcoal, 5 oz. Sawdust, 1½ --
_Sun cases._
1. Meal-powder, 8½ lbs. Saltpetre, 1 -- 2 oz. Steel-dust, 2 -- 10 -- Sulphur, 4 --
2. Meal-powder, 3 lbs. Saltpetre, 6 oz. Steel-dust, 7½ --
_Crowns or globes._
1. Saltpetre, 6 oz. Sulphur, 2 lbs. Antimony, 4 oz. Camphor, 2 --
This view of the compositions used in fixed and turning pieces, exhibits the various compounds which _have been_ employed, and, therefore, may be relied upon. Notwithstanding they are considered the standard formulæ; yet we must observe, that in some, particularly in the turning sun, with variations, changes are required, in order to produce a variety in the effect. This is accomplished, by making, in the first place, a particular composition, and mixing a given quantity of it with meal-powder, which forms the second change. Of this second composition, combined in a given proportion, with meal-powder, we form a third change; and, in like manner, we employ the third along with more powder, to form a fourth, and the fourth to form a fifth. The particular manner of making these changes will be described in a future section.
_Sec. II. Of Single, Vertical, Horizontal, Spiral, and other wheels._
Of the different kinds of _vertical wheels_, we may mention, that some have their fells of a circular form, others, in the form of a hexagon, octagon, or of a figure of a greater number of sides, according to the length of the cases designed for the wheels. The spokes being fixed in the nave, nail slips of tin, with their edges turned up, so as to form grooves for the cases to lie in, from the end of one spoke to another. Then tie the cases in the grooves head to tail, in the same manner as those on the horizontal water-wheel; so that the cases successively taking fire from one to another, will keep the wheel in an equal rotation. Two of these wheels are very often fired together, one on each side of a building, and both lighted at the same time, and all the cases filled alike to make them keep time together. This may be accomplished in the following manner. In all the cases of both wheels, except the first, and on each wheel, drive two or three ladles full of slow fire, in any part of the cases, but be careful to ram the same quantity in each case; and in the end of one of the cases on each wheel, one ladle full of dead-fire composition, which must be very lightly driven. Many charges of fire may be made by the same method.
The hole in the nave of the wheel may be lined with brass, and made to turn on a smooth iron spindle. On the end of this spindle, let there be a nut to screw off and on. When we have placed the wheel on the spindle, screw on the nut, which will keep the wheel from flying off. Let the mouth of the first case be a little raised.
Vertical wheels are made from ten inches, to three feet in diameter, and the size of the cases must vary accordingly. Four-ounce cases will be sufficient for wheels of fourteen or sixteen inches in diameter, which is the proportion generally used. The best wood for wheels of all kinds, is the light and dry beech.
_Horizontal wheels_ are more perfect, when their fells are made circular. In the middle of the top of the nave must be a pintle, turned out of the same piece as the nave, two inches long, and equal in diameter to the bore of one of the cases of the wheel. There must be a hole bored up the centre of the nave, within half an inch of the top of the pintle. Nail at the end of each spoke, of which there should be six or eight, a piece of wood with a groove, cut in it to receive the case. Fix these pieces in such a manner, that half the cases may incline upwards, and half downwards, and that, when they are tied on, their heads and tails, or extremities, may come very near together. From the tail of one case to the mouth of the other, carry a leader, which is necessary to be secured with pasted paper. Besides these pipes, a little meal-powder must be placed in the inside of the pasted paper, to blow off the pipe, that there may be no obstruction to the fire from the cases. By means of these pipes, the cases will successively take fire, burning one upwards, and the other downwards. On the pintle, fix a case of the same sort as those on the wheel. This case must be fired by a leader from the mouth of the last case on the wheel, which case must play downwards. Instead of a common case in the middle, we may put a case of Chinese fire, sufficiently long to burn a given time, or as long as two or three cases on the wheel.
Horizontal wheels are often fired two at a time, and made to keep time, like vertical wheels, only they are prepared without any slow or dead-fire. Ten or twelve inches will be sufficient for the diameter of wheels with six spokes.
With respect to _spiral wheels_, we may remark, that they are only double horizontal wheels, made in the following manner: The nave must be thicker than that of the single sort; and, instead of the pintle at top, a hole is usually made for the case to be fixed in. There are two sets of spokes, one set put near the top of the nave, and the other, near the bottom. At the end of each spoke, cut a groove, in which the cases are to be tied, there being no fell. The spokes should not be more than three and a half inches long from the nave, so that the wheel may not be more than eight or nine inches in diameter. The cases are placed in such a manner, that those at top play down, and those at the bottom play up; but let the third or fourth case burn horizontally. The case in the middle may begin with any of the others. Six spokes will be sufficient for each set; so that the wheel may consist of twelve cases, besides that on the top; the cases six inches each.
_Plural wheels_ are different from the former. They are made to turn horizontally, and consist of three sets of spokes, placed six at top, six at bottom, and four in the middle, which must be a little shorter than the rest. Let the diameter of the wheel be ten inches. The cases must be tied on the ends of the spokes, in grooves, cut on purpose, or in pieces of wood, nailed on the ends of the spokes, with grooves cut in them as usual. In clothing these wheels, make the upper set of cases play obliquely downwards, the bottom set obliquely upwards, and the middle set, horizontally. In placing the leaders, we must so arrange them, as that the case may turn thus: namely, first up, then down, then horizontally, and so on with the rest. But another change may be made, by driving in the end of the eighth case two or three ladles full of slow fire, to burn till the wheel has stopt its course. Then let the other cases be fixed the contrary way, which will make the wheel run back again. For the case at top, we may put a small gerbe, and the cases on the spokes may be short, and filled with the strong brilliant charge.
For forming the _illuminated spiral wheel_, we must proceed thus: First have a circular horizontal wheel, made two feet in diameter, with a hole quite through the nave; then take three thin pieces of light board, three feet long each, and three-fourths of an inch broad. One end of each of these pieces, nail to the fell of the wheel, at an equal distance from one another; and the other end, nail to a block with a hole in its bottom, which must be perpendicular to that in the block of the wheel, but not so large. Plane a hoop down very thin and flat, and nail one end of it to the end of the wheel, and wind it round three sticks in a spiral line, from the wheel to the block at top. On the top of this block, fix a case of Chinese fire. On the wheel may be placed any number of cases, which must incline downwards, and burn two at a time. If the wheel should consist of ten cases, we may let the illuminations and Chinese fire begin with the second cases. The spindle for this wheel must be a little longer than the cone, and made very smooth at top, on which the upper block is to turn, and the whole weight of the wheel to rest.
For making the _double spiral wheel_, the block, or nave, must be as long as the height of the worms, or spiral lines; but must be very thin, and as light as possible. In this block fix several spokes, which must diminish in length from the wheel to the top, so as not to exceed the surface of a cone of the same height. To the ends of these spokes nail the worms, which must cross each other, several times. These worms clothe with the same illuminations as those on the single wheels, but the horizontal wheel may be clothed according to fancy. At the top of the worm, place a case of slow fire, or an amber light.
_Balloon wheels_ turn horizontally. They are usually made two feet in diameter without any spokes, and very strong, with any number of sides. On the top of the wheel, range and fix in pots of three inches in diameter, and seven inches high each, as many as there are cases on the wheel. Near the bottom of each pot, make a small vent; and into each of these vents, carry a leader from the tail of each case. Some of the pots may be charged with stars and some with serpents, crackers, &c. As the wheels turn, the pots will be fired in succession, and throw into the air a great variety of fires.
_Fruiloni wheels_ are made with a nave, nine inches long, and three inches in diameter. Near the bottom of this nave, fix eight spokes with a hole in the end of each, sufficiently large to receive a two or four-ounce case. Each of these spokes may be fourteen inches long from the block. Near the top of this block, fix three more of the same spokes, exactly over the others, but not so long by two inches. As this wheel is to run horizontally, all the cases in the spokes, must play obliquely upwards, and all those in the spokes at bottom, obliquely downwards. This being accomplished, have a small horizontal wheel, made with eight spokes, each five inches long from the block. On the top of this wheel, place a case of brilliant fire. All the cases on this wheel must play in an oblique direction downwards, and burn two at a time; and those on the large wheel, four at a time; i. e. two of those on the top set of spokes, and two of those in the bottom set of spokes.
The four first cases on the large wheel, and the two first on the small, must be fired at the same time, and the brilliant fire at the top, at the beginning of the last cases. The cases of the wheels may be filled with a gray charge. When these wheels are completed, we must have a strong iron spindle, four feet six inches long; and fixed perpendicularly on the top of a stand. On this, we put the large wheel, whose nave must have a hole quite through from the bottom to the top. This hole must be large enough to turn easy round the bottom of the spindle, at which place there must be a shoulder, to keep the wheel from touching the stand. At the top of the spindle, put the small wheel, and join it to a large one with a leader, in order that they may be fired both together.
_Pin wheels_, as they are called, are formed by rolling some paper into pipes of about fourteen inches in length. The paper should be thin, and rolled of three thicknesses. When they are thoroughly dried, procure a tin tube, twelve inches long, to fit easy into the pipes. At one end of this tube, fix a small conical cup, which cone is called a funnel; then bend one end of one of the pipes, and put the funnel in at the other, as far as it will reach, and fill the cup with composition. Draw out the funnel gently, shaking it up and down, and it will fill the pipe, as it comes out. Having filled some pipes, procure some small blocks, about one inch in diameter and half an inch thick. Round one of these blocks, wind and paste a pipe, and to the end of this pipe, join another, which must be done by twisting the end of one pipe to a point, and putting it into the end of the other with a little paste. In this manner, join four or five pipes, winding them one upon another, so as to form a spiral line. Having wound on the pipes, paste two strips of paper across them to hold them together. The pipes must also be pasted together.
The other method of making these wheels is described thus: wind on the pipes without paste, and stick them together with sealing wax at every half turn; so that, when they are fired, the end will fall loose, every time the fire passes the wax, by which means the circle of fire will be considerably increased.
The formers for these pipes are made from 1-1/2 to 4/16ths of an inch in diameter. They may be fired on a large pin, and held in the hand with safety.
_Composition for Pin-Wheels._
Meal-powder, 8 oz. Saltpetre, 2 -- Sulphur, 1 -- Steel-filings, or the powder of cast-iron, ¼ --
The ingredients are to be well mixed, and dry. The mixture need not be very fine, or it will adhere to the funnel.
_Sec. III. Of Revolving Suns._
From what has been said in the preceding section, it is obvious, that revolving or turning suns may be formed, or any piece put in motion, in the manner already described. The most common mode of forming a sun, is to attach to three naves, which proceed from a hub, that revolves on a spindle, from three to six cases, placing them in such a way, that they may be fired successively. The jets, or spouts, proceeding from the cases, constitute the _rays_, the sun being in the centre, which revolves with the cases on an axis. The arrangement of these cases should be such, as that the six (as that number is usually employed,) might form the perimeter.
The cases may be charged with one, or with different compositions, given in the following table. They are attached in such a way, that the head of the first is nearly in contact with the _ray_ of the second, and that to the third, &c. When the first case is finishing, it must, therefore, communicate fire to the second, that to the third, and so on in succession. These cases must be attached firmly by wire; and leaders are used to communicate the fire, as in other works. The end must be enclosed in the neck of the first case, and the other end in that of the second, &c. They are secured in their respective positions, by tying them securely to the cases.
With respect to the composition employed, it may be varied according to pleasure. In most instances, however, the ordinary sun-composition is used; but, in other instances, this is varied according to circumstances. Morel has adopted the following composition for a sun of six cases, the cases being eight-twelfths of an inch in diameter. These cases are mounted on the arms of the sun in the same manner as before described.
_Composition for a sun with variations, the cases of which are eight-twelfths of an inch in caliber._
_No. 1, first change,_
Saltpetre, 16 oz. Sulphur, 6 -- Meal-powder, 3 --
_No. 2, second change,_
Composition No. 1, 2 oz. Meal-powder, 2 --
_No. 3, third change,_
Composition No. 2, 1 oz. Meal-powder, 1 --
_No. 4, fourth change,_
Composition No. 3, 1 oz. Meal-powder, 1 --
_No. 5, fifth change,_
Composition No. 4, 1 oz. Meal-powder, 1 --
_No. 6, sixth change,_
Meal-powder alone, for two changes.
It appears evident, that the changes thus produced are owing to the diminution of the quantity of saltpetre and sulphur, or, in other words, to the increase of the quantity of powder; and that the fourth change must contain but a small quantity of each, whilst the sixth or last change contains none, except that which is in the composition of the powder. The effect, therefore, must be proportionate; for, it must be apparent, that this diminution of nitre and sulphur, and the increase of powder, must render each charge more explosive, or, in other words, the combustion more instantaneous, and that this effect characterizes each of the changes in succession, is a result which necessarily follows.
The instructions given by Morel for employing these changes, in the charging of cases, are thus: We take the above composition for the third case of the sun. The first case is of common fire; the second of silver rain; the third of two charges of common fire, and afterwards a charge of No. 1, the second two charges of No. 2, the third three charges of No. 3, the fourth four charges of No. 4, the fifth four charges of No. 5, and two charges of No. 6. The fourth case is composed of brilliant fire; the fifth the same as the third, and the sixth of large or grand jessamine.
We may merely remark, that the sun must be supported very firmly, and that it ceases to revolve at the fourth, fifth, and sixth numbers.
_Sec. IV. Of Fixed Suns._
Fixed suns are so called, because they remain stationary, and exhibit the appearance of a sun with innumerable rays. A fixed sun is formed by putting eight or more strips of board across each other, so that each arm may proceed from a common centre, in which a sun is painted on silk. To the extremities of these arms are attached, to each one in succession, a case of brilliant fire, which, by means of bodies fixed in the usual manner, go off together. The two arms below, forming right angles with each other, are longer than the rest; so is also the upper and vertical arm. This, however, depends upon fancy. The cases are tied to these arms; and, after the leaders are fixed from the mouth of one case to that of the other, they terminate at the bottom and hang below the vertical arm. Fire is first communicated to the hanging match.
Fixed suns are usually employed as a decoration for other works. They are sometimes sixty feet in diameter, and variously decorated. They are commonly, however, ten feet. The fire extends a considerable distance, sometimes, it is said, to the distance of thirty feet; but this must depend on the size of the cases.
_Sec. V. Of Fixed Suns with Transparent Faces._
Fixed suns may be made with transparent faces in the following manner: Two rows of cases must be fixed in radii from the face of the sun, the sun being in the centre; and these cases, being placed alternately one above the other, and preserving the same distance all round, present what is called a double glory, and make the rays strong and full. The frame or sun-wheel is made thus: Have a circular flat nave, made very strong, 12 inches in diameter, and fix six strong flat spokes, proceeding from the circle that contains the sun's face to the extremity of the wheel, and also two other hoops, placed between it and the sun. To these, and the external wheel, the cases are tied. When the cases are tied on, leaders are attached from the upper to the under cases. The front of these spokes supports a circular fell, five feet in diameter. Within this is another fell, smaller in diameter by the length of one of the sun cases; and within this also is a third fell, whose diameter must be less than the second by the length of one case and one third. The fells are divided into as many equal parts as we employ cases, which may be from twenty-four to forty-four. At each division, fix a flat iron staple. These staples must be made to fix the cases and hold them fast on the wheel. The staples must be so placed, that one row of cases may lie in the middle of the intervals of the other. There is a spindle in the centre of the block of the sun, to which a small hexagonal wheel is put. The cases of this wheel must be filled with the same charge as the cases of the sun. Two cases must burn at a time, and begin with them on the fells. The pipes of communication are to be carried from one to the other, and from one side of the sun to the wheel in the middle, and from thence to the other side of the sun. They will hold the wheel steady, when the sun is fixing up.
A sun thus made is called a brilliant sun, as there appears nothing but sparks of brilliant fire, the wood-work being covered with fire from the wheel in the middle. A transparent face is usually made with pasteboard, by cutting out the eyes, nose, and mouth, for the sparks of the wheel to appear through. A face may be painted on oiled paper, or Persian silk, put over a hoop, and supported by three or four pieces of wire at six inches distance from the wheel in the centre. The silk may be painted according to fancy.
As to the size of cases for a sun of five feet in diameter, half-pound cases, filled ten inches with composition, is considered a good proportion.
_Sec. VI. Of the Rose-Piece and Sun._
This exhibition may be made in such a manner as to produce a pleasing effect. A rose-piece may be used for a mutation, or change of a regulated piece, or fixed by itself. It makes the best appearance, when made large. If its exterior diameter be six feet, it will be a good size. Let the exterior fell be made of wood, and supported by four wooden spokes. All the other parts, on which the illuminations are fixed, must be made of strong iron-wire. On the exterior fell, place as many half pound cases of brilliant charge, as will be sufficient; but the more, the greater will be the effect, for the nearer the cases are placed, the stronger will be the rays of the sun. The illuminations should be placed within three inches of each other. They must all be fired together, and burn some time before the sun is lighted, which may be done by carrying a leader from the middle of one of the illuminations to the mouth of one of the sun cases.
_Sec. VII. Of the Manner of changing a Horizontal to a Vertical Wheel, and representing a Sun in front._
In order to produce this change, the wheel for this purpose should be about three feet in diameter, and its fell circular, on which tie sixteen half-pound cases, filled with brilliant charge. Two of these cases must burn at a time. On each end of the nave is to be a tin barrel of the same construction as those on the regulated piece. We must then have a stand, made of any height, about three or four inches square, and saw off from the top a piece two feet long. This piece is then to be joined again, at the place where it was cut, with a hinge on one side, so that it may lift up and down in the front of the stand. Then fix on the top of the bottom part of the stand, on each side, a bracket, which must project, at right angles with the stand, one foot from the front, for the short piece to rest on. These brackets are to be placed a little above the joint of the post, so that, when the upper stand falls, it may lie between them at right angles with the bottom stand; which may be done by fixing a piece of wood one foot long between the brackets, and even with the top of the bottom stand. Then, as the brackets rise above the bottom stand, they will form a channel for the short post to lie in, and keep it steady without straining the hinge. On the side of the short post, opposite the hinge, nail a piece of wood of such a length, that, when the post is perpendicular, it may reach about one and a half feet down the long post; to which, being tied, it will hold the short stand upright. The stand being thus prepared, in the top of it, fix a spindle ten inches long. On this spindle put the wheel; then fix on a brilliant sun, with a _single glory_. The diameter of this sun must be six inches less than that of the wheel. When we fire this piece, attention must be paid to light the wheel first, and let it run horizontally till four cases are consumed. Then, from the end of the fourth case, carry a leader into the tin barrel that turns over the end of the stand. This leader must be met by another, brought through the top of the post, from a case filled with a strong port-fire charge, and tied to the bottom post, with its mouth facing the pack thread, which holds up the stand; so that, when this case is lighted it will burn the pack thread and let the wheel fall forward, by which means it will become vertical. Then from the last case of the wheel, carry a leader into the barrel, next the sun, which will begin as soon as the wheel is burnt out.
_Sec. VIII. Of Caprices and Fire-Wands._
Caprices are so called from the particular motion they assume, and are regulated according to the order and manner of their firing.
A perpendicular shaft, or post, is first provided, in which are placed two sets of spokes at some distance from each other. At the extremities of these spokes, joints are made, on which the cases are fixed. These cases communicate with each other by leaders. The first which takes fire, discharges upwards; the second, vertically; the third, horizontally; and the fourth, fifth, sixth, and seventh, go off at the same time; _viz._ the fourth, upwards; the fifth, vertically, a little inclined; the sixth, horizontally; and the seventh, vertically. The match of communication is fixed by a port-fire.
The arrangement of this piece, to produce the effect, depends on the construction of the wood work.
The great falling caprice differs from the foregoing in the following particular, that it separates itself in the midst of its fire into three parts. It is formed of three wheels, which appear as one; but at a certain time after the fire is communicated, they separate and occupy certain positions.
Mercury's Wand, as it is called, is formed by placing, across each other, two pieces of wood, and at the extremity of each four lances parallel to each other, and one obliquely. These lances of illumination must be connected by leaders. Circular bands are attached to the extremity of each leg, which terminates in the centre, and the wings or legs move in opposite directions. The double crescents, thus formed, produce, in turning, a variety of figures.
_Sec. IX. Of Palm and other Trees._
The representation of trees is considered an elegant fire-work. Palm trees are shown by fixing an upright piece, which serves as a trunk, and attaching to it a number of pieces, resembling in effect the branches of a tree. The extremities or branches are decorated with gerbes, and sometimes with marrons, arranged in such a manner that they may go off together.
For Yew trees, cases of brilliant fire, jessamine, or Chinese are used. In making this representation, the upright piece is usually four feet in length, two inches in breadth, and one inch thick. At the top we fix, on the flat side, a hoop fourteen inches in diameter, and round its edge and front, place illuminations, and in its centre a five-pointed star. At a foot and a half from the edge of the hoop, two cases of brilliant fire are usually placed, one on each side. These cases should be one foot long each. Below these are usually fixed two more cases, at such a distance that their mouths may almost meet those at top. Two other cases are sometimes added, which ought to be parallel with the last. The cases are then clothed with leaders, so that they, with the illuminations and stars at top, may all take fire together.
Fire trees may be formed by placing cases at an angle of 45 degrees, inclining upwards from the trunk, and at certain distances from each other. The two last cases may incline downwards. Cases may also be placed on the trunk itself, so that the whole will resemble a body of fire. Fire trees are commonly made about six feet long and three inches in diameter. The cases are generally fixed to pegs. At the top of the tree, a four-inch mortar is fixed, which is loaded with stars, rains, or crackers. In the middle of this mortar, we may place a case filled with any sort of charge, which must be fired with the other cases. Brilliant fire is generally employed. The fire is communicated, as in other works, by means of leaders, which are fired at the bottom.
There is also another exhibition often made with the so called _illuminated yew-tree_. The middle piece or stem on which the branches are placed, is generally eight feet six inches high. The branches all incline downward, and shorten as they go up. The number of branches on each side is six, and their length is determined according to judgment. When the branches are fixed, place illuminating port-fires on the top of each, as many as are required. Behind the top of the stem, fasten a gerbe or fountain of Chinese fire, which must be fired at the beginning of the illuminations on the tree.
Fires are often made to intersect each other, which has a good effect. For this purpose a perpendicular post is provided, of any thickness, so that it is sufficiently strong to hold the cases. There are two pieces of wood which go across the post, two feet six inches apart and two feet in length. On the end of each of these pieces there is usually a five-pointed star. Six stars are mostly employed. Pegs are fixed to the post in such a way that two of them incline upwards and two downwards, both forming an angle of ninety degrees, or forty-five degrees with the post. To these pegs are fixed half pound cases of brilliant fire. All the cases and stars must be fired at once. It is obvious that by this arrangement of the cases, the fires must cross, and thus by intersecting each other afford a greater variety.
_Sec. X. Of the Pyramid of Flower Pots._
This piece is formed by attaching to a post, ten or twelve feet high, and placed perpendicularly in the ground, four rails or pieces, two feet apart, which must diminish in length, so as to represent a pyramid. The bottom rail must be six feet long. On the bottom rail fix five paper mortars, each three and a half inches in diameter. Let one be opposite the post, and the other four equally distant on each side. Load these mortars with serpents, crackers, stars, &c. In the centre of each mortar fix a case of spur-fire. On the second rail fix four mortars so as to stand exactly in the middle of the intervals of those on the bottom rail. On the third rail, place three mortars, on the fourth, two; and on the top of the post, one. All the mortars must incline a little forwards, that they may easily discharge; and the spur-fire rammed exactly alike, that the mortars may all be fired at the same time. The pipes of communication being prepared, carry them from one spur-fire to the other.
_Sec. XI. Of the Dodecaedron._
The piece, required in forming a twelve sided figure, is prepared in the following manner: A ball must be turned out of solid wood, fourteen inches in diameter, and its surface is to be divided into fourteen equal parts. In each division bore holes of a half inch in diameter, perpendicular to the centre, so that they may all meet in the middle. In the inside of each hole, let there be turned a female screw. To all the holes but one must be made a round spoke, five feet long, with four inches of the screw at one end to fit the holes. In the screw end of all the spokes, bore a hole five inches up, which must be bored slanting so as to come out at one side a little above the screw. From these holes cut a small groove along the spoke, within six inches of the other end, where another hole through to the other side of the spoke is made. To this end fix a spindle, on which put a small wheel of three or four sides, each side six or seven inches long; these sides must have grooves cut in them, large enough to receive a two or four-ounce case. When these wheels are clothed put them on the spindles, and at the end of each spindle attach a nut to keep the wheel from falling off.
The wheels being thus fixed, carry a pipe from the mouth of the first case on each wheel through the hole in the side of the spoke, and from thence along the groove and through the other hole, so as to hang out at the screw end about an inch. The spokes being all prepared in this manner, a post must be provided on which the piece is to be fired, having an iron screw in the top of it to fit one of the holes in the ball. On the screw attach the ball and then in the top hole of the ball put a little meal-powder, and some loose quick-match. After this, screw in all the spokes, and in one side of the ball bore a hole, in which put a leader and secure it at the end. By this leader the powder and match in the centre are fired, which will light the match at the end of the spokes all at once, and by which all the wheels will be lighted at the same time. There may be an addition to this piece by fixing a small globe on each wheel, or one on the top wheel only. Gray charge may be used for the wheel cases.
_Sec. XII. Of Cascades of Fire._
Cascades of fire may be made of any size, and with cases from a half pound to a pound, or more. Half pound cases are usually the size employed. Cascades may be made either fixed, or turning. The former are an assemblage of pieces of wood, furnished with cases charged with Chinese fire, and placed one above the other. The distance may be more or less; sometimes from eight to fifteen feet. The latter, or turning cascades, are constructed about four feet in diameter. The wheel is made to turn on a pivot, and is put in motion by attaching to it, in the usual manner, cases of white fire. These play horizontally. The cases of Chinese fire, which play downwards, are fixed to the wheel, or to another wheel below this, or above it, according to fancy, and are placed with their mouths downwards. Sometimes in fact they play upwards, and for that purpose are made to incline outwards. In the centre, there is a case or two of brilliant fire.
It is obvious, that this arrangement not only gives a motion to the wheel, and to the cases of Chinese fire, but produces in effect a circular sheet, which falls like a cascade.
By having an upright piece, stuck in the ground, on which are fixed three or more horizontal wheels, or segments of a circle, made permanent, and at about three feet from each other, diminishing, however, as they go up, and also in their diameter, a frame will be formed capable of holding a great number of cases. The first segment may be four feet in diameter. The top pieces may be of any length, so as to hold the cases at a little distance from each other. All the cross pieces are to be fixed horizontally, and supported by brackets. The bottom cross piece, or segment, should be about one foot six inches broad in the middle; the second, one foot; the third, nine inches; and the top piece, four inches. The cases may be made of any length, but must be filled with a brilliant charge. Bits of wood ought to be nailed on the edges of the cross pieces, having a groove cut in each piece, and sufficiently large for a case to lie in. These bits of wood are fixed, so as to incline downwards, and that the fire from one tier of cases may play over the other. Leaders are carried from one to the other, as before mentioned. Let there be a pipe, hung from the mouth of one of these cases, covered at the end with a single paper, which is burnt to fire the cascade. Nine cases generally form the first tier; seven, the second, four, the third; and three, the last. These cases play downwards, except the three at top, one of which is vertical and the other two inclining at an angle of about forty-five degrees. The arrangement may be varied at pleasure. The only thing to be attended to is, to fix the cases in such a way, that the fire which proceeds from them may pass over the tier immediately underneath, that the effect may be general and uniform. Chinese fire may be used, as in the former instance.
_Sec. XIII. Of Chinese Fountains, and Parasols._
The manner of constructing the wood work of a Chinese fountain is as follows: Procure a perpendicular piece of wood, seven feet long, and two and a half inches square. At sixteen inches from the top, fix on the front a cross piece, one inch thick, and two and a half inches broad; with the broad side up. Below this, fix three more pieces of the same width and thickness, at sixteen inches from each other. Let the bottom rail be five feet long, and the others of such a length as to allow the fire-pumps to stand in the middle of the intervals of each other. The pyramid being thus made, fix in the holes, made in the bottom rail, five fire-pumps, at equal distances: on the second rail, place four pumps; on the third, three; on the fourth, two; and on the top of the post, one. Place them all, however, to incline a little forward, so that when they throw out the stars, they may not strike against the cross rails. The fire-pumps are to be clothed with leaders, in order that they may all be fired together.
Cases for _Fire-pumps_ are made in the same manner as those for tourbillons. See _Fire-pump_, and also _Fire-pots_ of various kinds.
The effect of these cases depends entirely on the star-composition. Stars, previously moulded, are introduced into them along with meal-powder.
Parasols are also formed with Chinese fire. A horizontal wheel is provided, and its circumference is clothed with eight or ten cases of that fire. These cases may be five-sixths of an inch in diameter, and, when inflamed, should throw their fire horizontally. The fire, in this instance, is made to resemble a _sheaf_; but the ordinary composition is generally used. The cases, however, should play horizontally. To make the wheel turn on its pivot, two cases of white fire are attached to it. The parasol, produced by the fire, is from twenty-five to thirty feet in diameter. It is formed in consequence of the fire coming in contact, and producing a concave sheet in its fall, resembling a parasol when extended.
_Sec. XIV. Of Wings or Cross Fire._
Nearly similar to one of the pieces described, that of the representation of a tree, is the cross-fire, or _wings_, a name given to it, because it resembles the sails, or wings of a windmill.
In forming this piece, two sticks, eight feet in length, are provided, and through the centre of each, a square hole is made, to receive a piece of iron of the same size, through which is a hole to admit a pivot.
When these sticks are put together, there must be a sufficient distance between them to prevent their rubbing each other. Five cases, charged with the composition of brilliant fire, are fixed to each extremity, proceeding towards the centre, at a short distance apart, and making in all twenty cases. Four of these cases are placed at each end, nearly horizontally, resembling the rounds of a ladder, the sticks being nearly vertical; and the one nearest the centre is placed almost vertically, or rather obliquely. The cases, being connected with leaders, when fired, turn with the sticks in an _opposite_ direction to each other.
When three wheels are each furnished with two rounds of white and coloured fire, and are so arranged, that the periphery of each should pass over in succession at the distance of ninety degrees of the perimeter, this piece is then called by the whimsical name of the _love-knot_.
_Sec. XV. Of Galleries of Fire, and Batteries of Roman and Mosaic Candles._
Galleries of fire are formed by attaching, to long strips of wood, at convenient distances from each other, cases of Chinese fire, which go off together. At the end of each case, is put a marron, which, when the case is burnt, ends with an explosion.
To form batteries with marrons, in connection with Roman candles, they are tied at two feet distance from each other, on long sticks, leaders being attached. These batteries, like the fire gallery, usually accompany other fire-works.
We may here remark, that _thunder_ is imitated by marrons, which are fixed in the same way two feet apart. To produce the effect, and increase the report, it is necessary to use them of different sizes, from a quarter of an inch to three inches caliber. They should be preceded by flashes of _lightning_, which is imitated either with powdered rosin, or lycopodium, in the manner described in our chapter on _Theatrical Fire-Works_.
_Sec. XVI. Of Girandoles, and their Modifications._
Girandoles, for the purpose here noticed, are nothing more than wheels which turn on a pivot. They are made of light wood, with a rim similar to that of a sieve, and are clothed with cases. Two cases are fired at a time, which burn in an opposite direction.
Girandoles may be made to imitate a parasol, by placing, horizontally, cases charged with the blue-fire composition, or with that of the Chinese fire. Cascades may be formed, by arranging them vertically, horizontally, and some at an angle of ten or fifteen degrees from the horizon. The _bunch of flowers_ is represented by using, at the same time, cases of 10/12ths, 11/12ths, and one inch, charged with Chinese composition, as given in the table for calibers of that diameter. See _Chinese Fire_. Crackers are formed by attaching Roman candles and Mosaic simples, and the sheaf is shown by fixing in the centre some empty cases, on which are strung small rockets, which are fired by the last case.
There are different modes of varying the effect of the girandole. They may imitate the fire-rain, by employing cases charged with that composition, which is given in the chapter on _Theatrical Fire-Works_.
_Sec. XVII. Of Cracking Caprices._
For this piece, a circular table is formed about twenty inches in diameter, and one inch and a quarter thick. There is a hole made in the centre, which is furnished with a pivot.
Twelve inches from the circumference, and at equal distances, eight holes are to be bored, to receive the same number of pots, of two inches caliber; and, in the immediate vicinity of the centre hole, which receives the pivot, four more are made, for four other pots.
Eight arms, three inches long, project from the table at equal distances, on which is fastened a hoop one inch in width. The fire-pots are now put in the different apertures, which are made sometimes to screw in; and the frame, of which we have spoken, is furnished with cases of brilliant fire.
It is necessary that this piece should go off at three fires; but the order of firing may be varied according to circumstances.
_Sec. XVIII. Of the Projected Regulated Piece of Nine Mutations._
A regulated piece, if well executed, is considered as curious in its effect as any other in pyrotechny. It consists of fixed and moveable pieces on one spindle, representing various figures, which take fire successively one upon another, without any assistance after lighting the first mutation.
I. Names of the mutations, with the colour of fire, and size of the case, belonging to each.
_First Mutation._--This is a hexagon vertical wheel, illuminated in front with small port-fires, tied on the spokes. This wheel must be clothed with two-ounce cases, filled with black charge. The length of these cases is determined by the size of the wheel, but each must burn singly.
_Second Mutation._--This is a fixed piece, called a golden glory, by reason of the cases being filled with spur fire. The cases must stand perpendicular to the block, on which they are fixed, so that, when burning, they may represent a _glory_ of fire. This mutation is generally composed of five, or seven two-ounce cases.
_Third Mutation._--This is moveable, and is only an octagon vertical wheel, clothed with four-ounce cases, filled with brilliant charge. Two of these cases must burn at a time. In this wheel, we may make changes of fire.
_Fourth Mutation._--This is a fixed sun of brilliant fire, consisting of twelve four-ounce cases. The necks of these cases must be a little larger than those of four-ounce wheel cases. In this mutation, may be made a change of fire, by filling the cases half with brilliant charge, and half with gray.
_Fifth Mutation._--This is a fixed piece called the _porcupine quills_. This piece consists of twelve spokes, standing perpendicular to the block in which they are fixed. On each of these spokes, near the end, must be placed a four-ounce case of brilliant fire. All these cases must incline either to the right or left, so that they may all play one way.
_Sixth Mutation._--This is a standing piece called the cross fire. This mutation consists of eight spokes fixed in a block. Near the end of each of the spokes, must be tied two four-ounce cases of white charge, one across the other; so that the fires from the cases on one spoke may intersect the fire from the cases on the other.
_Seventh Mutation._--This is a fixed wheel with two circular fells, on which are placed sixteen eight-ounce cases of brilliant fire, in the form of a star. This piece is called a fixed star of _wild fire_.
_Eighth Mutation._--This is a beautiful piece, called a brilliant star piece. It consists of six spokes, which are strengthened by two fells of a hexagon form, at some distance from each other. At the end of each spoke, in the front, is fixed a brilliant star of five points; and on each side of every star is placed a four-ounce case of black or gray charge. These cases must be placed with their mouths sidewise, so that their fires may cross each other.
_Ninth Mutation._--This is a wheel piece. It is composed of six long spokes, with a hexagon vertical wheel at the end of each. These wheels run on spindles in front of the spokes. All the wheels are lighted together. Two-ounce cases will be sufficient for these wheels, and may be filled with any coloured charge.
II. With respect to the proportion of these mutations, with the method of conveying the fire from one to the other, and the distance they stand from each other on the spindle, the following general remarks will be sufficient.
The _first mutation_ must be a hexagon vertical wheel fourteen inches in diameter. On one side of the block, whose diameter is two and one-fourth inches, is fixed a tin barrel. This barrel must be a little less in diameter than the nave. Let the length of the barrel, and block be six inches. Having fixed the cases on the wheel, carry a leader, from the tail of the last case, into the tin barrel, through a hole, made on purpose, two inches from the block. At the end of this leader, let there be about one inch, or two, of loose match; but be careful to secure the hole, in which the pipe is put, to prevent any sparks falling in, which would light the second mutation before its time, and confuse the whole.
The _second mutation_ is thus made. Have a nave, turned two and a half inches in diameter, and three long; then let half an inch of that end, which faces the first wheel, be turned, so as to fit easy into the tin barrel of the first mutation, which must turn round it without touching. On the other end of the block, fix a tin barrel No. 2. This barrel must be six inches long, and only half an inch of it to fit on the block. Round the nave, fix five spokes, one inch and a half long each. The diameter of the spokes must be equal to a two-ounce former. On these spokes, put five seven-inch two-ounce cases of spur-fire, and carry leaders from the mouth of one to the other, that they may all light together. Then, from the mouth of one of these cases, carry a leader through a hole bored slantwise in the nave, from between the spokes to the front of the block, near the spindle hole. The end of this leader must project out of the hole into the barrel of the first mutation; so that, when the pipe, which comes from the end of the last case on the first wheel, flashes, it may take fire and light the second mutation. To communicate the fire to the third mutation, bore a hole near the bottom of one of the five cases to the composition; and from thence carry a leader into a hole, made in the middle of the barrel. This hole must be covered with pasted paper.
The _third mutation_ may be either an octagon or hexagon wheel, twenty inches in diameter. Let the nave be three and a quarter inches in diameter, and three and a half in length. One and a half inches of the front of the nave must be made to fit in the barrel No. 2. On the other end of the block, fix a tin barrel No. 3. This barrel must be six and a half inches in length, one inch of which must fit over the block. The cases of this wheel must burn two at a time, and, from the mouths of the two first cases, carry a leader through holes in the nave, into the barrel of the second mutation, after the usual manner. But besides these leaders, let a pipe go across the wheel from one of the first cases to the other. Then, from the tail of one of the last cases, carry a pipe into a hole in the middle of the barrel No. 3: at the end of this pipe, let there be some loose quick match.
_Fourth and Fifth Mutations._--Their naves are made of one piece, which, from the barrel of the fourth, to the commencement of the sixth, is fourteen inches. The block of the fourth is four inches in diameter, having ten or twelve short spokes, on which are fixed eleven inch eight-ounce cases. The front of this block must fit easy in the barrel of the third wheel. Clothe the cases, so that they may all light together; and let a pipe be carried through a hole in the block into the barrel No. 3, in order to receive the fire from the leader, brought from the last case on the wheel. The nave of the fifth mutation must be four and a half inches in diameter, and furnished with ten or twelve spokes, eighteen inches in length each. These spokes must stand seven inches distant from the spokes of the fourth mutation, and, at the end of each spoke, tie a four-ounce case as No. 5. All these cases are to be lighted together, by a leader brought from the end of one of the cases on No. 4.
_Sixth and Seventh Mutations._--The blocks of these two mutations are turned out of one piece of wood, whose length from the barrel of the fifth wheel, to the block of the eighth wheel, is fifteen inches. The block of the sixth wheel is five inches in diameter, having eight spokes, each two feet four inches long. At the end of each spoke, tie two four-ounce cases, as in No. 6. All these cases must be fired at the same time, by a pipe brought from the end of one of the cases on the fifth mutation. Let the distance between the spokes of the sixth, and those in the fifth mutation, be seven inches. The nave of the seventh mutation must be five and a half inches in diameter, and furnished with eight spokes. On the front of them, two circular fells, one of four feet eight inches in diameter, and the other, three feet eleven inches, are to be fixed. On these fells, tie sixteen eight-ounce cases, or pound cases, as in No. 7, and carry leaders from one to the other, so that they may be fired at the same time. This mutation must be fired by a leader, brought from the tail of one of the cases on the sixth mutation.
_Eighth and Ninth Mutations._--The blocks of these may be turned out of one piece, whose length from the barrel of the seventh mutation to the block of the ninth, must be twelve inches. The block of the eighth, six inches in diameter, must contain six spokes, each three feet in length, and strengthened by an hexagon fell, within three or four inches of the ends of the spokes. Close to the end of each spoke, in the front, fix a five-pointed brilliant star, and seven inches below each star, attach two ten-inch eight-ounce cases, so that the upper ends of the cases may rest on the fells, and their ends on the spokes. Each of these cases must be placed parallel to the opposite fell.
_Ninth Mutation._--The block of the ninth mutation is seven inches in diameter, and holds six spokes, six feet long each, with holes and grooves for leaders, as those in the dodecaedron. At the end of each spoke in the front, fix a spindle for a hexagon vertical wheel, ten inches in diameter, as in No. 9. When these wheels are on, carry a leader from each into the block, so that they may all meet. Then lead a pipe from the end of one of the cases of the eighth mutation, through a hole bored in the block of the ninth, to meet the leaders from the vertical wheels, in order that they may be fired together.
Having thus given a brief description of this complicated work, the performance of which depends so much on the accuracy of its parts, we will now add a few remarks respecting the formation of spindles.
For the larger pieces, the spindles should be made very strong and exact. The instructions on this head are, that for a piece of nine mutations, let the spindle be, at the large end, one inch in diameter, and continue that thickness as far as the seventh mutation, and from thence to the fifth, let its diameter be three-quarters of an inch. The other proportions, then, are, from the fourth to the second, half an inch; and from the second to the end, three-eighths of an inch. At the small end must be a nut, to keep on the first wheel, and at the thick end, a large nut; so that the screw part of the spindle being put through a post, and a nut screwed on tight, the spindle will be held fast and steady. The wheels, however, ought to run easy and without sticking. The fixed pieces are made on different blocks, and the leaders must be joined, after they are fixed on the spindle. The best method of preventing the fixed mutations from moving on the spindle, is to bore a hole a little larger than the diameter of the spindle; and, at each end of the block, over the hole, fasten a piece of brass, with a square hole in it to fit the spindle.
Similar to this piece of nine mutations is the _Pièce Pyrique_ of the French, which consists of a great variety of fixed and moving pieces, that are fired alternately, but in regular succession. This piece we purpose to describe in the following section.
_Sec. XIX. Of the Pyric or Fire-Piece._
This, we have remarked, is a combination of pieces, calculated, like the one we have described, to produce a variety of fires, variously arranged and distributed.
The pyric piece commonly commences with a turning sun. This sun consists of three cases, fixed to three arms proceeding from the centre. They are attached by means of a string, and have leaders which go from one to the other of the cases. See _Sun_. This sun communicates its fire to a fixed sun, formed of eight or nine strips of board, crossing each other, or as many spokes from a hub, to which are attached, lengthwise, as many cases, whose mouths are made to communicate fire by means of leaders; so that each case presents the appearance we have before described. Then follows a wheel consisting of two or more concentric circles, and round which are placed eight cases, with their mouths inclining a little upwards. These cases are generally charged with brilliant fire. They communicate with each other in the usual manner, and afterwards with a fixed star, placed on a stick, proceeding from the horizontal axis. This star is made of two cases, charged with Chinese fire, with their mouths upwards, and forming, with each other, an angle of forty-five degrees. This fire is then communicated to another wheel, and from that to one, on which, at certain distances, are fixed six smaller wheels, furnished with six cases each; so that the whole are put in motion at one time, the fire being communicated at the same period. The appearance of these smaller wheels, as the cases may be charged with the coloured fire-composition, is such as to exhibit the motion of a screw; which, however, depends on the structure of the wheel. The fire from this may then communicate to other wheels of the same kind, to cases of brilliant fire, to marrons and the like, differently arranged according to fancy. Cylinders of copper or tin, called _barrels_ by some, are used in the arrangement, in the manner already described. In fact, the remarks we have before made on the regulated piece of nine mutations, the manner of forming as well as of executing it, will apply to the Pyric-piece.
_Sec. XX. Of Sundry Illuminated Figures._
There are various illuminated pieces, some of which we purpose to notice in this section.
The illuminated pyramid, with Archimedean screws, a globe, and vertical sun, may be exhibited in the following manner: Let a pyramid be made twenty-one feet in height, and the height of the pedestal six feet, and breadth nine feet, having a space between the rails of six inches. They must be made as thin as possible, and in all put port-fires at intervals of four inches. The Archimedean screws are placed on the pedestal. They are nothing more than double spiral wheels, on which the cases are placed, but horizontally instead of obliquely. The vertical sun, placed four feet below the top of the pyramid, may consist of twelve rays. The globe on the top may be made in proportion to the pyramid. The leaders must be prepared and arranged in such a manner, that all the illuminating port-fires, or lances, screws, globe, and sun may take fire together.
Transparent stars with illuminated rays are formed, by making a strong circular block or body for the star, two feet in diameter, and attaching to it illuminated rays. In the centre of the front of the body, fix a spindle, on which put a double triangular wheel, six inches in diameter, clothed with two-ounce cases of brilliant charge. The cases on this wheel must burn only one at a time.
Round the edge of the body, nail a hoop made of thin wood or tin, which must project in front six or seven inches. In this hoop, cut three or four holes to let out the smoke from the wheel. The star may be cut out of strong pasteboard or tin in the following manner: Cut a round piece of pasteboard, two feet in diameter, on which draw a star, and cut it out. Over the vacancy, paste Persian silk, and paint the letters yellow; and also four of the rays yellow, and four red. This transparent star is to be fixed to the wooden hoop by a screw, to take off and on. The illuminated rays are made of thin wood, with tin sockets, fixed on their sides, within four inches of each other. In these rockets, put the illuminating port-fires, or lances; and behind the point of each ray, attach a half pound case of gray, black, or Chinese fire. The illuminated rays are to be lighted at the same time as the triangular wheel, or after it is burnt out. This may be done by a tin barrel, in the manner described in the regulated piece. Into this barrel, carry a leader from the illuminated rays, through the back of the star, which must be met by another leader, brought from the tail of the last case on the wheel.
The regulated illuminated spiral piece, with a projected star wheel, also illuminated, is made by procuring a block, eight inches in diameter, and putting in six iron spokes, which serve for spindles for the spiral wheels. These wheels are made one and a half feet in diameter, and three feet in height. The spindles must be of sufficient length to keep the wheels four or five inches from one another. At the end of each spindle, put a screw nut. On these spindles, the wheels, that hang downwards, are to run. On the spindles, which stand upwards, must be a shoulder, for the blocks of the wheels to run on. The projected star wheel turns on the same spindle on which the large block is fixed. This spindle must be long enough to admit the star-wheel to project a little before the spiral wheels. The exterior diameter of the star wheel is five feet five inches. On this wheel, three circles of iron wire are to be fixed, to which attach either port, or other illuminating fires. On the block, place a transparent star, or a large five-pointed brilliant star. The cases on this wheel may burn four at once. The cases on the spiral wheels must be placed parallel to their fells and burn two at a time.
In order to make a figure-piece, with five-pointed stars, illuminated, all that is necessary is to have a vertical wheel about one foot in diameter, and furnished with six four-ounce cases of different coloured charge, which must burn double. On the frame of the figure piece, fix five-pointed brilliant or blue stars, rammed four inches with composition. Let the space between each star be eight inches, and, at each point, fix a gerbe or case of Chinese fire. The gerbe, stars, and wheel are to be lighted at the same time.
The illuminated star wheel may be formed by procuring a fell about four feet in diameter, and placing, within this fell, three circles of iron wire, one smaller than the other, so that the diameter of the least may be about ten inches. Place the port, or other fires on these fells, with their mouths inclining outwards, and the port-fires on the points of the star, with their mouths projecting in front. The exterior fell must be clothed with four-ounce cases of gray charge. They must burn four at a time and be lighted at the same time with the illuminations.
The illuminated regulating piece as it is called, consists of flat wooden spokes, each five feet long, and at the end of each, a vertical wheel, ten inches diameter, and clothed with six four-ounce cases of brilliant fire. These cases burn one at a time. On two of the spokes of each wheel, two port-fires are attached, which must be lighted with the first case of the wheel. On each spoke, behind the wheels, place six cases of the same size with those on the wheels. These cases must be tied across the spokes with their mouths in one direction, and be made to take fire in succession.
The diameter of the large wheel must be two and a half feet, and its fell made of wood, which is to be fixed to the large spokes. Twenty-four cases of the same kind are fixed on this wheel, and burn four at a time. On the circles of iron-wire, already mentioned, illuminating port-fires are attached. The star-points on the large spokes may be made of thin ash-hoops. The diameter of these points, close to the centre wheel, is usually eleven inches. On these, port-fires are placed, three and a half inches distant from each other.
The illuminated double cone-wheel is nothing more than a double cone, formed of a number of hoops, and supported by three or four pieces of wood, in the manner of the spiral wheels. The wheel to which the cones are attached, base to base, is two feet six inches in diameter, and the height of each cone is three feet six inches. Port-fires, or lances, are tied to each of the hoops, in a horizontal direction, with their mouths outwards. The cases are eight-ounce, and play horizontally, two at a time. The spindle for this piece must rise three feet above the point of the cone at top; so that its length will be ten feet four inches from the top of the post, in which it is fixed, allowing four inches for the thickness of the block of the wheel. The whole weight of the wheel and cones must be made to bear on a shoulder in the spindle, on which the block of the wheel is to turn. On the top of the spindle, fix a sun, composed of sixteen four-ounce cases of brilliant fire. These cases must be stuck into a block, six inches in diameter. In the front of this sun, put a circular vertical wheel, sixteen inches in diameter. On the front of this wheel, form a spiral with wire, to which attach illuminations in the usual manner. This wheel is to be fired, when the cones are burnt out, which may be done as before described. The sun must not be fired, until the vertical wheel is burnt out. Three vertical wheels illuminated, which turn on their own naves upon a horizontal table, is a piece readily formed. It consists in having a table, three feet in diameter fixed horizontally on the top of a post, with three wheels that turn round on it. There are three spokes, joined to a triangular flat piece of wood, in the middle of which, a hole is made to fit easily over a spindle placed in the centre of the table. There are three pieces of wood four or five inches long, and two inches square, fixed on the under sides of the spokes. In these pieces, holes are made lengthwise, to receive the thin parts of the blocks of the wheels, which, when in, are prevented from coming out by a small iron pin that runs through the end of each. The three vertical octagon wheels, each eighteen inches in diameter, have blocks sufficiently long, for three or four inches to rest on the table. Round these a number of sharp points of wire are driven, (which must not project out of the blocks more than 1/16th of an inch), and the clothing is affixed in the usual manner. The use of the points is this, that, when the blocks turn round, they will stick in the table and assist in giving a uniform motion to the wheel. On the front of the wheels, make four or five circles of strong wire, or flat hoops, and tie, on these circles, as many illuminations, as they will hold, at two inches from each other. Spiral lines may be made instead of circles. When illuminations are fixed in a spiral line, in the front of a wheel, they ought to be placed on the slant. The cases for these wheels may be filled with any coloured charge, but must burn only one at a time. A globe, or spiral wheel may be put on the spindle, so that its fire may play over the vertical wheels. The wheels must be lighted at the same time, and the illuminations, after two cases of each wheel are consumed.
The vertical scroll wheel is formed by taking a block of a moderate size, and fixing in it four flat spokes, and, on them, a flat circular fell of wood. Round the front of this fell, port-fires are placed; and on the front of the spokes a scroll is formed either with a hoop or strong iron-wire. On this scroll, tie cases of brilliant fire in proportion to the wheel, head to tail. When the first case near the fell is lighted, the fire is communicated in succession. The grand volute, with a projected wheel in front, is made in the following manner: Two hoops are formed of strong iron wire, one of six feet in diameter, and the other of four feet two inches. These hoops must be joined to scrolls, formed according to fancy, of the same kind of wire. On these, tie, with iron wire, as many illuminating port-fires, as they will carry, at two inches distance. Prepare then a circular wheel of four spokes, three feet six inches in diameter, and, on its fell, tie as many four-ounce cases, head to tail, as will complete the circle, only allowing a sufficient distance between the cases, that the fire may pass free. On each spoke, fix a four-ounce case, about three inches from the fell of the wheel. These cases are to burn one at a time, and the first of them to begin with those on the fell, of which four are to burn at a time. On the front of the wheel, form a spiral line with strong wire, on which tie port-fires, with their mouths to face the same way as the cases on the wheel. All these port-fires must be fired with the second cases on the wheel.
The spokes of the wheel must be formed of wood, and made to screw into a block in the centre, and each spoke should be four feet six inches in length. In the top of each, fix a spindle, and, in each spindle, put a spiral wheel of eight spokes. The blocks of these wheels must have a hole at top for the centre cases, and the spindle must be furnished with nuts, screwed on their ends, which should fit in the holes at the top of the blocks. The cases of these wheels are to burn double; and the method of firing them, is by carrying a leader from each down the spokes into the block in the centre, as in the dodecaedron; but the centre cases of each wheel must begin with the two last cases as usual. The large circular wheel in front ought to have a tin barrel on its block; into which a pipe must be carried from one of the second cases on the wheel. This pipe, being met by another from the large block, in which the eight spokes are screwed, will fire all the spiral wheels, and the illuminating port-fires at the same time. The cases of the projected wheel may be filled with a white charge, and those of the spiral wheels with a gray.
_Sec. XXI. Of the Spiral or Endless Screw, and Waved Fire._
This piece is formed in the same manner as the single and double cones; and, in fact, is the same as the Archimedean screw, which we have already described. The serpentine form which characterizes the spiral piece, is given to it by the particular arrangement of the lances of illumination. The cone receives its motion from the cases of white-fire; the fire of which is communicated by leaders to the cases of port-fire, or lances of illumination. They must burn the same length of time.
The waved fire is produced by having two wheels of a similar size, turning in a contrary direction on the same axis, and furnished with cases, which are inclined about 45 degrees from the level of the table. These wheels carry four cases each, and burn at the same time. They have been made to carry forty-eight cases, and furnished, at their centres, with lances, bent in a particular manner, so as to represent the motion of serpents.
_Sec. XXII. Of the Decoration of Wheels._
Wheels, we have seen, may be made of different dimensions, according to the purpose to which they are applied. The most common are three or four feet in diameter, with a nave of hard wood, and spokes of light wood. They are sometimes surmounted with a fell, and frequently by several concentric hoops, placed at different distances from each other.
Wheels, in general, are furnished with cases, and various decorations. Some have two, three, four, and more fires; but, if they are _finished_ too much, the weight they thus acquire would retard the velocity of the wheel. Their centres may be finished in several ways; as, for instance, by attaching, to the inner fells or circles, cases filled with white lance-composition, placed at the distance of two inches from each other, or alternately, white, blue, and yellow, or Chinese gerbes, or cases of blue fire. We may also attach small turning suns, the axes of which being placed upon the spokes. They may also be made to resemble a mirror, by furnishing all the spokes with white lances; and for the last fire, we may attach four cases to the centre, or in its vicinity, placed in such a manner, that their fire may issue from the interior of the wheel. To this, we may add, two other cases, which may cross the former. Leaders are fixed, and they are lighted at the same time.
Automatons with all their joints, or articulations, have been added to exhibitions of this kind, and with particular effect. They are clothed with cases after the usual manner.
_Sec. XXIII. Of Globes, with their Various Decorations._
The first we purpose to treat of are the illuminated globes with horizontal wheels.
The hoops for these globes may be made of wood, tin, or iron wire, about two feet in diameter. For a single globe, take two hoops and tie them together, one within the other, at right angles; then have a horizontal wheel made, whose diameter must be a little wider than the globe, and its nave six inches long; on the top of which, the globe is fixed so as to stand three or four inches from the wheel. On this wheel may be put any number of cases, filled with any of the ordinary charges, as the white fire composition. Two of these cases must burn at a time. They may be placed horizontally, or inclining downwards. When the wheel is clothed, fix on the hoops as many illuminations as will stand, within two and a half inches of each other, which are fastened on the hoops with small iron wire. Attach the pipes of communication, and arrange them so as to carry the fire to all at the same time, with the exception of one or two, which are to receive their fire for the last. The spindle, on which the globe is to turn, must go through the block of the wheel up to the inside of the top of the globe; at this place must be fixed a bit of brass or iron, with a hole in it, to receive the point of the spindle, on which the whole weight of the wheel is to bear. When the globe is to be stationary and the wheel to run by itself, the block of the wheel must not be so long, or the spindle any longer than to raise the globe a little above the wheel.
We may remark, that, while the cases of white fire composition give to the piece a rotary motion, those of the lance or illuminating port-fire produce the effect, which characterizes in particular this fire-work.
With respect to fire globes, there are two kinds; namely, one with projected cases, and the other with concealed cases. If we have a globe made of wood, of any diameter, and divide its surface into twenty-four equal parts, and bore a perpendicular hole in each of these divisions to the centre, we may then represent this piece in the following manner: In every hole, except one, put a case filled with brilliant or any other charge, and let the mouths of the cases be even with the surface of the globe. Then cut in the globe a groove from the mouth of one case to that of another for leaders, which must be carried from case to case, so that they may all be fired together. The globe is then covered with a single paper and painted.
Fire globes with projected cases are made in the following way: Prepare a globe with fourteen holes, and fix in every hole except one, a case, and let each case project from the globe two-thirds of its length. Then clothe all the cases with leaders. It must be supported by a spindle made to fit the hole in which there is no case.
The _bursting-globe_ is nothing more than a globe prepared in a particular way. It turns on a pivot, and is made by uniting four segments. These segments or parts are fixed to hinges, which open on the inside, and, when brought together, are kept in their place by a match which goes round the globe. The globe, it is to be observed, is furnished in the inside with several steel springs, which, unless the globe itself were tied, would force it open. When the match is burnt, this effect follows and the globe separates into four parts. It is furnished with lances and cases in the same manner as those already described. The last effect is that we have noticed.
_Globes, which leap or roll on the ground_, may be formed by procuring a wooden globe, furnished with a cylinder; and, having loaded it with the composition hereafter mentioned, introduce into it four or more petards loaded with grain powder to their orifices, which must be well stopped with paper or tow. If a globe prepared in this manner be fired by means of a match at the mouth of the cylinder, it will leap about as it burns on a smooth horizontal plane, according as the petards are set on fire. The petards may be affixed to the exterior surface of the globes, which they will cause to roll and leap as they catch fire.
_Composition._
Grained powder, 1 lb. Saltpetre, 32 -- Sulphur, 8 -- Scraped ivory, 1 oz. Sawdust, (boiled in saltpetre and dried,) 8 lbs.
_Sec. XXIV. Of the Representation of the Moon and Stars._
The moon and stars are represented in the following manner: Make a wheel eighteen inches in diameter, by fixing eight or more spokes in the nave; and then adapt a fell to it. To the fell fasten eight cases of the black or gray composition, and let the fire communicate from one to the other. These cases give motion to the wheel. Furnish the spokes of this wheel with cases charged with the white lance composition. Make now a crescent of iron and attach it to the spokes, or a little before the spokes of the wheel. In order to fix stars to this piece, eight strips of wood, seven feet in length, are made to cross each other at equal distances, and nailed to each other in the middle; so that when this frame is put behind and secured to the moon-piece, its arms will extend some distance beyond the perimeter of the wheel. These projections are furnished with five-pointed stars, eight inches apart, and there is usually in all thirty-two. They are made to communicate with each other by means of the cotton match, as before described. The light of the lances renders the moon very apparent, and the fixed stars resemble those in the firmament. The representation of the moon and seven stars may be performed by procuring a smooth, circular board, six feet in diameter. Out of the middle of it cut a circular piece twelve or fourteen inches in diameter, and cover the hole formed with Persian silk, on which is to be painted a moon's face. Also cut out of the board stars of four or five inches in diameter. These stars are cut out with five points and covered with oiled silk. On the front of the large circular board draw a seven-pointed star, as large as the circle will admit, and on the lines which form this star, make several perforations, in which six-pointed stars are to be fixed. A wheel of brilliant fire is placed behind the moon, which renders the moon and stars transparent. They will disappear when the wheel is burnt out; but then in consequence of the communication of the fire to the large star in front, which is formed of pointed stars, the appearance of this star succeeds, and finishes the piece.
A large fixed star may be made thus. To each extremity of the pieces of wood, arranged so as to cross each other, attach two cases of the black charge. Their fire must communicate. Near these cases, on each arm, place a turning sun of three cases. These five suns are fixed at the same time, and when they cease, the cases commence. These cases form the star.
The representation of flaming stars, with brilliant wheels, is made in the following manner. After procuring a circular piece of wood, about one inch thick, and two feet in diameter, fix round it eight points, each two feet and a half long, four of which must be straight and four waved, or flaming. These points being joined on very strong, and even with the surface of the wood, nail tin or pasteboard on their edges, from the wood to the end of each, where they must be joined. This tin is to project in front eight inches, and be joined where they meet at the block. Round the front of the wood, fix four pieces of thick iron wire, eight inches long each, equally distant from each other. Cut a piece of pasteboard round, two feet in diameter, and draw on it a star; then cut out this star, and on the back of it, place oiled paper. Paint half red and half yellow, lengthwise. The body of the star must be left open in which must be seen a brilliant wheel. This wheel is formed by having a block turned nine inches long, and fixing in it six spokes. At the end of each spoke, put a two-ounce case of brilliant fire. The length of these cases is made in proportion to the wheel, and the diameter of the wheel, when the cases are on, must be less than the diameter of the body of the small star. The cases on the spokes in front must have their mouths inclined outwards, and those on the inside spokes, placed so as to form a vertical circle of fire.
Carry the first leader, from the tail of one of the cases in front, to the mouth of one of the inside cases, and from the tail of that to another in front, and in the same order to all of them. Put on a spindle in the centre of the star. This spindle must be furnished with a shoulder at bottom, to keep the wheel at a little distance from the block, which is kept on the spindle by a nut at the end. Having fixed on the wheel, fasten the transparent star to four pieces of wire. When fired, a common horizontal wheel will only be seen; but when the first case is burnt out, it will fire one of the vertical cases, which will show the transparent star and fill the large flames and points with fire. It will then appear like a common wheel, and represent the same appearance for twelve changes.
With respect to the formation of stars for regulated pieces, we may remark, that they are made of different sizes according to the work for which they are intended. They are prepared with cases from one ounce to one pound; but, in general, with four-ounce cases, four or five inches long. The cases should be rolled with paste, and twice as thick of paper as a rocket of the same caliber. Having rolled a case, let one end of it be pinched quite close; then drive in half a diameter of clay, and, when dry, fill it with composition to two or three inches of the length of the case. At the top of the charge, drive some clay; as the ends of these cases, being seldom pinched, would be likely to take fire. Divide the case, when filled, at the pinched end close to the clay, into five equal parts; then bore five holes with a gimblet, about the size of the neck of a common four-ounce case, into the composition. From one hole to another, carry a quick match, and secure it with paper, in the same manner as the ends of wheel cases; so that the hollow part, which projects from the end of the case, may serve to receive a leader from any other work, to give fire to the points of the stars. These stars may be made with any number of points.
_Sec. XXV. Of the Representation of Sundry Figures in Fire._
Animals and various figures may be represented in fire by the following method: Take sulphur, reduced to a very fine powder, and, having formed it into a paste with starch, cover the figure of the thing to be represented, with this mixture, having first coated it with clay to prevent it from being burnt. After the figure is covered with paste, it must be sprinkled, while moist, with gunpowder; and, when the whole is perfectly dry, arrange about it several small matches, that the fire may be speedily communicated to it on all sides. In this way, all sorts of garlands, festoons, and other ornaments may be imitated by fire of different colours.
A shower of fire may be connected with this representation, by using cases of one-third of an inch in diameter, charged with any of the following compositions. These cases should be two inches and a half in length. They must not be choaked, it being sufficient to twist the end of the cartridge. The effect of these cases is to fill the surrounding air with an undulating fire. The compositions are similar to those already noticed; viz. for _Chinese Fire_, take gunpowder one pound, sulphur two ounces, pulverized cast-iron of No. 1. five ounces; for _ancient fire_, meal-powder one pound, charcoal two ounces; and for _brilliant fire_, meal-powder one pound, and iron filings four ounces. Sparks are also sometimes employed. These are made in the usual manner.
Besides the common mode of forming sparks, as they differ from stars only in their size and duration, (being formed into small balls about the size of peas), they may be made by the following method: Take sawdust of fir, poplar, &c. and boil it in water, in which saltpetre has been dissolved. When the water has boiled some time, it is to be poured off, that the sawdust may remain in the vessel. When nearly dry, spread it out on a table, and sprinkle it with sulphur, sifted through a very fine sieve, to which may be added a little meal-powder.
If it be required to accompany the exhibition with bearded rockets, (_fusées chevelues_ of the French), so called from the circumstance, that, when they fall, they make small undulations in the air like frizzled hair, we may form them in the following manner: Fill the barrels of some goose-quills with the composition of sky-rockets, and place upon the mouth of each a little moist gunpowder, both to keep in the composition, and to serve as a match. If a flying-rocket be then loaded with these quills, they will produce, at the end, a beautiful shower of fire.
_Sec. XXVI. Of the Representation of Flat Stars, with a large Body of Fire._
A star of five points, about two feet from point to point, is to be made, and, in its centre, is placed a turning sun, composed of three cases, and altogether not more than six or eight inches in diameter. To this star five branches are fixed, each of which is three feet in length; and, to the extremity of each, are attached seven cases, with their mouths outwards, and inclining about thirty-five degrees. One case is then attached lengthwise, and forms the very extremity of each projection. On each leg or branch, nearer, however, the centre of the star, must be three cases, fixed in an hexangular form. The border of the large star is decorated with Italian or fixed stars. The fire is communicated to the star by means of a leader, then to the sun and the cases on the branches.
_Sec. XXVII. Of the Single, Double, and Triple Table Wheel._
We have spoken of an arrangement of fire-works, which moves a wheel on a circular board. That contrivance is similar to the one we now purpose to describe.
The table-wheel is a kind of girandole, which turns circularly on a round table, by having its axis connected with a perpendicular pin, fixed in the table; so that its motion is vertical, while it moves in a circular position round the table.
The table, as well as the wheel, may be of any size, according to fancy. Eight or nine cases are usually attached to the fell of the wheel, and in the direction of the fell. These cases turn it with great velocity. The centre of the wheel may be decorated with lances, or illuminating port-fires. When double or treble wheels are to be arranged on the same table, this is done by having the iron so lengthened, as to extend over the table, and receive another wheel of the same size; and by using a contrivance of iron, having three projections, at equal distances apart, and turning in the same manner on a pivot, or pin, fixed in the centre of the table, three wheels may be put in motion at the same time. When two wheels are employed, we may decorate one with blue lances, and the other with yellow. When three wheels form the same piece, it is usual to illuminate them, severally, with white, blue, and yellow lances. The wheels of coloured fire augment the beauty of the exhibition. In the centre of the table, may be placed a pyramid, decorated in the usual manner. Spiral wheels, globes, &c. may be attached, if so required.
_Sec. XXVIII. Of Decorations, Transparencies, and Illuminations._
Cut-work, as it is called, is often employed in decorations. Various figures, letters, garlands, &c. may be represented. This may also be accomplished in tambour-work. Several methods have been used to produce the same effect. Cut-work, made in pasteboard, and the pasteboard blackened and suspended in a frame, will, by the aid of lights placed behind it, exhibit the design very perfectly. A figure of a sun cut out of pasteboard, either fixed or made to revolve in the manner before described, and illuminated by fixed lights or revolving cases, is considered to be the best mode of forming such pieces. In all instances, the more brilliant the fire, the more perfect is the representation. Tambour decorations are variously arranged; and, frequently, in the termination of an exhibition, six or more are shown at once, and sometimes with cascades, and turning suns.
In the place of cut-work, painted transparencies, made with fine colours, and on Florence Taffeta, are usually employed. Transparent paintings however, are not preferred by some, as the effect, it is said, is not so perfect as when cut-work is employed. Morel gives a preference to the latter.
Transparencies may be formed with silk, or fine linen, and even with paper, if previously prepared, by means of the spirit of turpentine. The colours are painted in turpentine, and transparent varnish is then applied.
Transparent screens may be prepared, by spreading white wax, dissolved in spirits of turpentine, over thin muslin. A screen, thus prepared, will roll up without injury. A clearer screen may be produced, by having the muslin stretched upon a rectangular frame, and prepared with turpentine instead of wax.
In the _Œuvres de Diderot_, t. xv, p. 349, are observations respecting transparencies, and the manner of preparing them. The process described is nothing more than we have noticed. It consists in using the oil of turpentine, and sometimes a solution of wax in turpentine. The colours are prepared mostly with turpentine. Canada balsam, thinned by the addition of the spirit, is also employed. Moveable transparencies were exhibited with great effect in Paris. Transparent figures were made to move continually in every direction, which had a singular appearance. Artificial fire-works were very accurately imitated, by producing a variety of movements with different pieces of transparencies, variously coloured. The sun, moon, and stars, revolving wheels, &c. composed a part of this exhibition.
With respect to decorations in white and coloured lances, we may observe, that artificial fire-works are usually terminated by some decoration, which corresponds with the subject. For this purpose, triumphal arches, fronts of palaces, colonades, rocks, &c. are formed, and represented in wood-work. These are usually clothed, and painted in water-colours. From the rocks, water is made to issue, forming cascades, and a number of figures are put in motion. The jets of water are terminated by jets of Chinese fire, or brilliant fire-rain.
The furniture, or decorations, may be various, either with white or coloured lances of illumination, hung four inches apart, and attached to different parts of the figure, or building. If it is in front of a temple, the columns are ornamented with emblems, &c. the fire-work being thus arranged: _viz._ blue lances are attached to the columns, white lances to their entablature, and to the emblems, yellow lights. This however, depends on taste.
Decorations are also made with matches; but this mode is not preferred, because so much smoke is thereby produced.
Figures, cut in paper, are illuminated in the manner before described. But for this purpose, muslin is first stretched on a frame, and its sides are covered with two or three thicknesses of paper, which are pasted on. It is then blackened. After tracing the design, or the subject of the illumination, and cutting it out with exactness, the frame is put in a case, sufficiently deep to contain a number of lights.
Illuminations, as an expression, of public feeling for some event or memorable occasion, are by no means a recent thing. Various modes have been adopted to render such exhibitions more elegant, as well as more expressive. Hence, with the usual display of lights, arranged according to taste and fancy, transparencies, decorations, such as we have described, &c. have been more or less customary.
We mentioned, in the first part of our work, something in relation to the antiquity of illuminations; but, as this subject may be interesting, we deem the following brief remarks not irrelevant.
Beckman assures us, (_History of Inventions_), that the origin of illuminations is very ancient. The feasts, or holy-days were celebrated in the days of antiquity, in various ways, among which, that with lamps was very common in Egypt. It was called the feast of the lamps, (_Fête des Lampes_), and the inhabitants of some cities in Egypt were obliged to illuminate, with a great number of lamps, placed before their houses. Herodotus (_lib._ ii, _chap._ 62), remarks, that, at a particular festival of the Egyptians, lamps were placed before all the houses throughout the country, and kept burning the whole night. During the _festum encæniorum_, the Feast of the Dedication of the Temple, which, according to common opinion, was celebrated in December, and continued eight days, a number of lamps were lighted before each of their houses. Such illuminations were used, also, in Greece and Rome, and were called _Lampadaria_. An infinite number of lamps were burnt in honour of Minerva, Vulcan, Prometheus, Bacchus, &c. On the last occasion, the illumination was called _Lamptericæ_. It seems that the lighting of streets had not been adopted at that period.[25] At Rome, the forum was lighted, when games were exhibited in the night-time; and Caligula, on a like occasion, caused the whole city to be lighted. As Cicero was returning home late at night, after Cataline's conspiracy had been defeated, lamps and torches were lighted in all the streets, in honour of that great orator. The emperor Constantine caused the whole city of Constantinople to be illuminated with lamps and wax candles on Easter-eve. The first christians often illuminated their houses on idolatrous festivals, in a more elegant manner than the heathens. This was dictated by policy. The houses of the ancients were illuminated on birth-days, by suspending lamps from chains.
For illuminations at the present day, tallow is chiefly used. It is clarified, for the making of candles, by means of alum. M. Olaine in 1710 presented to the academy of sciences an apparatus for the manufacture of candles. The _bougie economique_ of the French is described in the _Journal de Paris_ for 1782. The outline of the process for preparing them is as follows: Take eight parts of suet, and melt it with one quart of water; and after straining it, and returning it to the same boiler, add the same quantity of water, in which was dissolved half an ounce of saltpetre, as much sal ammoniac, and one ounce of alum. The boiling is continued to evaporate the water. The wick is made of cotton or flax, and rolled in a solution of camphor in petroleum, and afterwards covered in the usual manner with the above composition.
In using tallow generally, quicklime is recommended to be added to it in fusion. When the quicklime subsides, it is poured off. Another mode recommended is to melt the tallow with vinegar, and to add to it a decoction of rosemary, sage, laurel, and a small quantity of turmeric; the whole being boiled until the water is evaporated. This communicates, it is said, an agreeable odour, and a yellow colour. Different modes of preparing tallow for candles have been used. See _sal ammoniac_. With respect to ancient lamps, some account of them has been published in the _Antiquities_, by Montfaucon and by Passeri; and the _Journal des Savants_ 1682 and 1685 mentions the two lamps of Boyle and Sturmius, and some account of the celebrated lamp of Callimacus in the temple of Minerva. On the formation of lamps, and the purification of oil, sundry patents have been granted both in France and England. The argand lamp for burning its own smoke, which it effects by a glass cylinder placed over the flame, is one of the best improvements of the kind. The principle of these lamps is the same, although variously modified in shape and structure. For chemical purposes, an iron cylinder is substituted for glass. A lamp, for the burning of tar and turpentine, with steam, has lately been invented by Mr. Morey, (_see Silliman's Journal Vol. II._) Mr. E. Clarke obtained a patent for a lamp calculated to burn tallow; the principle of which is, that by the heat of the flame, the caloric is conducted to the tallow by means of a piece of iron, which is heated by it, and the tallow melts as it is wanted. This lamp may be economically used, when common lamp oil is scarce and high in price. A lamp is described in the _Repository of Arts_, to burn tallow.
As a wick, besides cotton, several substances have been recommended. The filaments of amianthus, for instance, while they perform the office of a wick, are incombustible. The _Journal de Verdun_ for 1748, announced incombustible wick by sieur Lespar. Touch wood, the _tussilago sarfara_, and the _verbascum tapsus_ of Linnæus, are also recommended. In 1783, Leger announced, in the _Journal de la Blancherie_, that he had invented a match which would burn without smoke and odour.
Lamps have been furnished with fixed and moveable mirrors, to throw the light forward by reflection. The reverberatory lamps, revolving lights for light houses, &c. are of this kind. Many patents have been obtained for such contrivances, which we have not room to notice.
The inflammable air lamp for the table, described in the _Dictionnaire de l'Industrie_, is nothing more than a spirit of wine lamp, and used in lieu of hot bricks, or vessels filled with boiling water for the warming of dishes, &c. In 1780, M. Ehrman, in his _Description et usage de quelques lampes à air inflammable_, describes a chafing dish with inflammable air, invented by Nevet, which operates by the combustion of hydrogen gas.[26]
Fixed illuminations are more brilliant and more magnificent; as the lights are more numerous, as well as more diversified. Wax, spermaceti, or tallow candles, or oil burnt in tin lamps, or in glass cups suspended by wire, are all used for the purpose. If the wick be dipped in spirit of turpentine, it will take fire instantaneously. It is unnecessary to make any remarks as to the arrangement of lights.
Large dishes containing melted tallow, and a wick proportionally thick and suspended by means of a simple contrivance of tin, are recommended for the same purpose. Coloured lights afford a variety. The appearance of coloured flame may be produced by burning the oil in coloured glasses, so disposed as to let the light pass through the glass, or by placing lamps behind bottles filled with coloured water.[27]
The coloured glasses which are sold in Paris for the purpose, are formed with facets on the outside, which not only produce the appearance of coloured flame, but also, according to the number of facets, the refraction and reflection of the light. Arches, pyramids, obelisks, &c. are lighted up in this manner.
The Pont Neuf, and the Seine in 1739, were illuminated at the time of the splendid exhibition of fire-works. It is unnecessary, however, to particularize on this head. We all remember the splendid illuminations in all our cities during the late war, which were indeed a true expression of our national and individual feeling. Illuminations, in this country, before that time were very rare; none we think since the peace of 1783, and the union under the federal compact.
Phosphuret of lime, of the size of peas, thrown into water, will afford, at short intervals, a brilliant flame of fire; for the phosphuretted hydrogen gas thus produced has the property of inflaming spontaneously in atmospheric air. Alcohol, containing sundry salts in solution, will give a flame of various colours, according to the salt it holds in solution. See _Alcohol_.
Illuminated works are much admired by the Italians, and particularly the _Illuminated chandelier_, which is considered a great addition to a collection of works. An illuminated chandelier is formed of thin wood with arms extending on each side. Holes are bored in the front of the branches and in the body, and also in the eagle (if it be added,) at top, and distant from each other about three inches. In these holes, we put illuminations, filled with white, blue and brilliant charge. Having fixed in the port-fires, they must be clothed with leaders, so that the chandelier and eagle may light together.
We may also observe, that, for the speedy lighting of a number of lamps, at one and the same time, quick-match enclosed in paper tubes has been used. This quick-match is sometimes made to communicate its fire to a sulphur match, prepared by dipping strands of cotton in melted sulphur, and from this to the lamp. Several methods are recommended for this purpose; one of which consists in dipping cotton wick in the oil of spike, and arranging it along the wicks of the different lamps, so that when inflamed the fire may pass rapidly from one lamp to another. In 1772, M. Renault, a Parisian, announced in the public papers, that he possessed a secret, by which he could light 2000 lamps in five minutes, by means of a match of communication.
We have some experiments and observations on coloured flame, by Mr. Morey, in his essay on heat and light, in the second volume of Silliman's _Journal of Science and Arts_, p. 120. The experiments are curious, and worthy of remark. If water, he observes, be put into one cylinder, and made to boil, and the steam be led to the bottom of another included cylinder, containing spirits of turpentine, the steam, when let out under a moderate pressure, carries off with it a sufficient quantity of the spirit to burn with a pleasant _white_ flame, free from smoke; but if the pressure be increased, the flame will become in part or wholly blue. "Here," he adds, "as in many other experiments, I have noticed, that different coloured flames may be produced from the same materials--are the products of combustion different?" He further observes, that "if the steam of water, containing a small proportion of the vapour of rosin, be driven against iron, at or below a red heat, it burns with a pleasant _blue_ flame, which will be extended some way back into the column of the vapour, intermixed with innumerable sparks of very white flame, evidently particles of the rosin. If the vapours, when the proportion of the rosin is very small, are made to pass between two plates of iron, at or near a red heat, they can be inflamed on the opposite sides of the plates, and will then, sometimes, burn with an entirely _blue_ flame, although the vapour can not be inflamed, without the intervention of the plates." He states other experiments, made with tallow and steam, producing a _blue_ flame. The _blue_ colour seems to be owing to the pressure made use of; for, in his second communication, (page 122, of the same volume), he mentions white flame being produced by the vapour of water; and when it is in a sufficient quantity, there is _no smoke_. If too great, combustion ceases. Speaking of the colour of the flame, produced by mixed vapours, (of the combustible and water), such as blue, blue and white, white and intense white, he adds, that they may be imitated, at pleasure, with the patent lamp stove, by burning tar, pitch pine, or mineral coal and water. Newly made charcoal will take up about three times its weight of water. "Sand, ashes, or fine clay," he observes, "answers well for mixing with the tar, &c. If the latter be made into a paste with equal parts of spirit of turpentine and water, and cold lumps of it, of a conical form, be placed on a table, and a flame applied, the vapours burn without smoke for a short time, &c. If enclosed in a tin cylinder, and the vapour be made to issue through small holes at the top, placed as before stated, or on a plate over a chafing dish of coals, it burns with a very bright light, free from smoke. If the cylinder be tight at the top and the vapour be led from the inside at the top, down and through the bottom, and there be made to issue in an oblique direction, and from a number of small openings, it will burn with a beautiful flame and supports and regulates, very accurately, its own evaporation. The oblique direction carries the heat, in part, beyond the cylinder, when the evaporation is too great.
"Every effect may be produced in consuming the smoke, and giving an intense white flame, by using a certain proportion of water, intimately blended or mixed with these vapours, that can be from an access of oxygen furnished, by creating a very strong current of air, with a high flue." The description of Morey's lamp stove, may be seen in the same work. The steam, he observes, may be furnished by a small tin boiler, and directed to or near the bottom of the tar. An _intense white flame free from smoke_, may be thus produced from tar, rosin, rough turpentine or the spirit, alcohol, oil, fat, tallow, mineral coal, pitch pine wood, and the knots, birch bark, and pumpkin, sun-flower, flax, and other seeds. With regard to pine wood, he adds, it is the easiest managed, evaporates at a lower temperature, consumes a greater proportion of water in its combustion, contains the water within itself, and gives a brighter light than common candles or lamps, and without smoke. The more volatile parts are evaporated at a temperature below that of boiling water, and burn well with three parts of the vapour of water; the flame then, however, is nearly _blue_. Observations on the application of this mode of producing light and heat, may be seen in Silliman, p. 131, &c. It appears, that Gay-Lussac (_Annales de Chimie_, for June, 1819,) has commented on Mr. Morey's plan.
Professor Hare (_Silliman's Journal_, vol. 2d, p. 172) also observes, that the flame of hydrogen gas is rendered luminous, like that of oil, by adding a small quantity of oil of turpentine to the usual mixture for generating this gas; and that the addition of 1/17 of the same fluid to alcohol, will give it the property of burning with a highly luminous flame; and there is a certain point in the proportions, at which the mixture burns without smoke, like a gas light. In the first instance, he observes, when the ingredients are at the proper temperature, the light is greater than that produced by carburetted hydrogen gas. Speaking of this application of spirits, the professor judiciously adds: "It might be serviceable to _morals_, if the value of this article could be enhanced by _a new_ mode of consumption." We find, also, that the effect of vapour on flame has been noticed by Dr. Dana, in the same Journal, vol. 1, p. 40; by which it appears, that when a jet of steam is made to pass into a charcoal fire, the vividness of the combustion is increased, and also the low attenuated flame of the coal; that it prevents the smoke of a common oil lamp, and makes the flame brighter; that the flame of spirit of turpentine, which is usually dull and reddish, is rendered bright, and no smoke is formed; or when the vapour of both are made to issue together from the same orifice, and inflamed, no smoke appears; that a jet of steam, thrown into the flame of a spirit of wine lamp, or into flames which evolve no smoke or carbonaceous matter, produces the same effect as a current of air; but that, in all flames which evolve smoke, steam produces an increased brightness and a more perfect combustion. Dr. Dana further suggests, that steam might be introduced into the flames of street lamps, which might be so contrived as to keep water boiling, to produce the steam, and thereby cause a more perfect combustion, and a greater quantity of light from the same materials.
Count Rumford has shown, that the quantity of light, emitted by a given portion of inflammable matter in combustion, is proportional, in some high ratio, to the elevation of temperature; and that a lamp, having many wicks near each other, so as mutually to increase their heat, burns with infinitely more brilliancy than the Argand lamps in common use. To measure the proportional intensities of two or more lights; place them a few inches asunder, and at the distance of a few feet or yards from a screen of white paper, or a white wall. On holding a small card near the wall two shadows will be projected on it, the darker one by the interception of the brighter light, and the lighter shadow, by the interception of the duller light. Bring the fainter light nearer to the card, or remove the brighter one further from it, till both shadows acquire the same intensity. Measure now the distances of the two lights, from the wall or screen, square them, and you have the ratio of illumination. Thus, if an Argand flame and a candle, stand at the distances of 10 feet and 4 feet, respectively, when their shadows are equally deep, we have 10^2 and 4^2, or 100 and 16, or 6-1/4 and 1, for their relative quantities of light.
The author of the _Dictionnaire de l'Industrie_, vol. iii, p. 365, in treating on the subject of illumination, mentions different modes of illuminating, both with and without transparencies. We know that various mixtures will produce different coloured flame. Thus, arsenic will burn with a beautiful white flame in oxygen gas; iron and steel will burn also, affording a brilliant light; phosphorus and charcoal with a white, and sulphur with a beautiful blue flame; zinc with a green colour, &c.
Again, we know that a mixture of nitrate of strontia and charcoal will burn with a rose coloured flame; one part of boracic acid, and three of charcoal, with a green flame; one of nitrate of barytes, and four of charcoal, with a yellow flame; and equal parts of nitrate of lime and charcoal powder, with an orange flame. We also know, that cotton dipt in oil of turpentine, or ardent spirit, rosin, camphor, &c. will burn extremely vivid and beautiful.
The author, whom we have just quoted, gives some remarks on the various coloured flames, that may interest the reader.
_Felt_ (_Feutre_, Fr.) he remarks, if put in the fire, will give most beautiful colours, a golden yellow and a brilliant blue. And this, he adds, may be proved by throwing pieces of old hats into the fire; for these colours depend on the substances used in dying the hat. He further remarks, that green oak wood gives a yellow flame, and alcohol with sedative salt, (boracic acid), a blue, and that, by uniting the flame of both, the product, as to colour, will be a green.
The flame of alcohol is changed of various colours, according to the salt it holds in solution. Of this circumstance, Schatt was apprised, when he gave some formula many years ago, on the manner of forming coloured flame. Reaumur remarked also, the different colours which some metals assume, when submitted to the action of heat, which is known now to be the effect of oxidizement.
As respects the phenomena with felt, we are told, that, if we throw into the fire the cuttings of hats, we will perceive at first a white flame, and then in succession a blue, green, and violet colour; all which, our author observes, proceeds from the verdigris and other substances, employed in the composition of the dye stuff. There is one fact, which he has asserted, which may probably be explained on the _materiality_ of light, so far as regards the _formation_ of colour, (not considering, however, the theory of Bancroft, given in his _Philosophy of Permanent Colours_, or the more philosophical one of Dr. Samuel Conover, of Philadelphia, in the Transactions of the _American Philosophical Society_), and this fact is, that the flame carries the colour to the object which it illuminates, and that the object itself actually partakes of the colour, in order to produce any particular appearance. That colours, as visible to the eye, are all formed in the solar light, and their appearance depends upon the _absorption_ of some of the rays of light, and the _reflection_ of others, is a doctrine which followed the discoveries of Sir Isaac Newton. We have not room to notice this subject, however interesting it may be in a philosophical point of view.
There can be no doubt, that the art of colouring flame was known for a long time. We are told, that the philosopher Anaxilaus even pretended, that, by putting ink with the oil of a lamp, or the liquor of the cuttle fish, the faces of the bystanders will appear _black_ by the light of this lamp! Sulphur has the effect of rendering the visage pale and cadaverous. Other persons, as Simon Sethe, advanced an opinion, that, if we moisten the wick of a lamp with ink, or in a mixture of the rust of copper, and having lighted the wick, and placed other lights around it, the faces will appear, some black, and some of a brass colour. Others, such as Cardan, say, that, by making a mixture of wine and salt, and then reducing it two-thirds by evaporation, the flame, which the wine will then give, will make the _living_ put on a cadaverous appearance, if they remain in one posture. Malina also observes, that, by burning a piece of woollen cloth well soaked in a solution of salt in vinegar, the visage will appear frightful by the light of the flame. But the process of J. B. Porta is not less worthy of note. If good old wine, he observes, be put into a bowl with a handful of salt, and set on live coals, but not in the flame, and as soon as it begins to boil, is set on fire, (the other lights in the room being extinguished), the figure of each person will appear so hideous, as to produce a mutual dread. The author of the _Dictionnaire de l'Industrie_, iii, p. 433, observes, that he has repeated this experiment, sometimes with brandy, and at other times with alcohol, with perfect success.
A cadaverous appearance is said to be given, by mixing common salt with alcohol, in which some saffron had been infused. When set on fire, and the other lights extinguished, the effect, we are told, is very striking.
The so called _miraculous luminaries_, are nothing else than solar phosphori, which are very numerous. Their effect is to emit light in the dark, but not heat. Almost every thing in nature possesses this property in a greater or less degree, which depends on the absorption and subsequent transmission of light. The eyes of various animals have this property; cats and owls in particular. Snow possesses it in a considerable degree. Putrid animal matter, fish, for example, rotten wood, &c. partake also of this property.
It may not be improper to notice, in a general way, some of the substances, which are denominated solar phosphori. The _Bolognian phosphorus_ is the calcined baroselenite, (sulphate of barytes), which, when exposed a few minutes to the light, shines when taken into the dark like burning coals. In water it emits the same light. This property, as is the case with all other solar phosphori, it loses gradually; but by heating it again, imbibes light. _Canton's phosphorus_ is calcined oyster shells. It is used in the same manner. _Baldwin's phosphorus_ is fused nitrate of lime. Various saline and other bodies, as diamonds and precious gems, possess the same property. Expressed oils and animal fats, when heated to 450°, become phosphorescent.
Hanzelet (_Traité des Feux d'Artifice_) remarks, that a _stone_ may be made to give light by water, if prepared in the following manner. Take quicklime, tutty, and saltpetre, of each one part; reduce them to powder, and expose them to the action of heat. On the addition of water, light is said to be given out.
When quicklime is mixed with essential oil, and brought in contact with water, spontaneous combustion is said to take place.
Fluor or Derbyshire spar, (fluate of lime), when pulverized and heated to 212° Fahr., and then removed to the dark, is very luminous. If writing be made on a copper or iron plate, with thin mucilage or white of egg, and powdered fluor spar, sprinkled on it; when the plate is removed to a gentle coal fire, the delineated objects will become luminous, and opaque again when the plate becomes cold. The lapis lazuli has the same effect.
The phosphoric substances, which become luminous by attrition or percussion, are numerous. _Homberg's phosphorus_, which is nothing more than calcined muriate of lime, is of this character. When struck it emits light. Without either light or fire, a number of bodies will give out light. Flints, and other siliceous stones, struck against one another, appear luminous in the dark. Various other minerals have the same property. Wedgwood (_Phil. Trans._ 179,) Coates (_Nich. Jour._ 1799,) Westrumb (_Crell's Chem. Annals_, 1784,) have written on this subject; to which enumeration we may add the interesting remarks of Dr. Hulme, (_Phil. Trans._ 1800,) and the observations of Cabarris, in his Memoir, read before the National Institute.
It may be sufficient to remark, that the shell-fish called _pholas_; the _meduca_ phosphorea, and other _molluscsæ_; several insects of the species _fulgora_, or lantern-fly; the _lampyris_, or glowworm; the _scolopendra electrica_; the _cancer fulgens_; the medullary substance of the human brain, &c. are all phosphorescent.
M. Dessaignes (_Bulletin de la Société Philomatique, Octobre_, 1810) made a number of experiments on solid, liquid, and aeriform bodies, relative to the disengagement of light by compression. Among other conclusions, he adds, that water is the cause of the spontaneous phosphorescence of bodies, such as quicklime, Canton's phosphorus, dry muriate of lime, &c. all which, when brought in contact with water, emit light, which he attributes to the consolidation of that fluid. The absorption of moisture, and its subsequent consolidation, may, in some instances, give rise to luminous appearances.
The _lapis solaris_, Bolognian stone, or the present sulphate of barytes, was discovered in 1602, by Casciorolus, a shoemaker of Bologna. He came to Scipio Begatello, who at that time was particularly known by his attachment to the art of gold-making, and showed him this stone, under the mystical name of _lapis solaris_, on account of its attracting the _golden_ light of the sun, and its boasted fitness for converting the _semi-metals_ into gold, the _sol_ of the alchemists!
Dr. Brewster (_Edinburgh Philosophical Journal_) made a number of experiments on the colour and intensity of light, evolved by different minerals, by which it appears, that the yellow sulphate of barytes gives a pale light, while fluate of lime, a blue and green light. Cellini (_Treatise on Jewelry_, published near the beginning of the 16th century) was the first who observed the phosphorescence of minerals; it does not appear that he knew of the Bolognian stone. Grimshire (_Nicholson's Journal_, 8vo. vols. 15, 16, 19,) made a number of experiments on the emission of light by bodies, when subjected to the electrical influence; and, when thus treated, sulphate of barytes gave a brilliant green light.
The _cawk_ of the miners, as it is also a sulphate of barytes, phosphoresces when previously exposed to heat.
There are two water fountains, both set in motion by the action of heat on confined air, which, as it expands, forces the water from an under vessel in jets. The first is called the _illuminated fountain_, and plays when the candles are lighted, stopping when they are extinguished. The other is a fountain, which acts on the same principle, but by the heat of the sun. The effect of the first is more or less considerable according to the pressure of the air upon the water, and consequently, to the degree of rarefaction which the air undergoes.
The _chemical illumination_ of some writers, by using oil of vitriol, iron filings, and water, and inflaming the vapour as it proceeds from a bottle, is nothing else than the inflammation of hydrogen gas. The "white vapours," which they describe, is the gas in question.
Having noticed the use of candles and lamps for illumination, we purpose, in concluding this article, to give the result of some experiments on the relative intensities of light, and duration of different candles, made by Dr. Ure, which we extract from his _Dictionary of Chemistry_.
----------+----------+---------+----------+---------+---------+--------- Number | Duration | Weight | Consump. | Propor- | Economy | Candles in a | of a | in | per hour:| tion of| of |equal one pound. | candle. | grains. | grains. | light. | light. | argand. ----------+----------+---------+----------+---------+---------+--------- 10 mould | 5 h. 9 m.| 682 | 132 | 12¼ | 68 | 5.7 10 dipped | 4 36 | 672 | 150 | 13 | 65½ | 5.25 8 mould | 6 31 | 856 | 132 | 10½ | 59½ | 6.6 6 do. | 7 2½ | 1160 | 163 | 14⅔ | 66 | 5.0 4 do. | 9 36 | 1787 | 186 | 20¼ | 80 | 3.5 Argand | | | | | | Oil Flame | | | 512 | 69.4 | 100 | ----------+----------+---------+----------+---------+---------+---------
The doctor remarks, that 1/8th of a gallon of good seal-oil, weighs 6010 gr. or 13 and 1/10th oz. avoirdupois, and lasts, in a bright argand lamp, 11 hours 44 minutes. The weight of oil it consumes per hour, is equal to four times the weight of tallow in candles, 8 to the pound, and three and one-seventh times the weight of tallow in candles, 6 to the pound. But its light being equal to that of 5 of the latter candles, it appears, from the above table, that 2 lbs. weight of oil, in an argand, are equivalent, in illuminating power, to three pounds of tallow candles. The larger the flames in the above candles the greater the economy of light.[28]
_Sec. XXIX. Of Imitative Fire-Works._
Imitative fire-works are nearly of the same character as the transparencies and illuminations mentioned in the last section; but, as this subject may be interesting to some of our readers, we thought proper for that reason to appropriate a section to its consideration.
Imitative fire-works are formed in the following manner: Take a paper that is blacked on both sides, or instead of black, let it be coloured on each side with a deep blue, which will be still better for such as are to be seen through transparent papers. It must be of a proper size for the figure intended to be exhibited. In this paper, cut with a pen-knife several spaces, and with a piercer make a great number of holes, rather long than round, and at no regular distance from each other.
To represent revolving pyramids and globes, the paper must be cut through with a pen-knife, and the space cut out between each spiral should be three or four times as wide as the spirals themselves. They must be so cut, that the pyramid or globe may appear to turn on its axis. The columns that are represented in pieces of architecture, or in jets of fire, must be cut in the same manner as if they are to be represented as turning on their axis.
In like manner may be exhibited a great variety of ornaments, cyphers, and medallions, which, when properly coloured, cannot fail of producing a most pleasing effect. There should not be a very great diversity of colours, as that would not produce the most agreeable appearance.
When these pieces are drawn upon a large scale, the architecture or ornaments may be shaded; and to represent different shades, pieces of coloured paper must be pasted over each other, which will produce an effect that would not be expected from transparent paintings. Five or six pieces of paper, pasted over each other, will be sufficient to represent the strongest shades. To give these pieces the different motions they require, we must first consider the nature of each piece: if, for example, we have cut out the figure of the sun, or of a star, we must construct a wire wheel of the same diameter with those pieces. Over this wheel a very thin paper is to be pasted, on which is drawn with black ink the spiral figure. The wheel thus prepared, is to be placed behind the sun or star, in such a manner that its axis may be exactly opposite the centre of either of those figures. This wheel may be turned by any contrivance.
Now, the wheel being placed directly behind the sun, for example, and very near to it, is to be turned regularly round and strongly illuminated by candles placed behind it. The lines that form the spiral will then appear through the spaces cut from the sun, to proceed from its centre to its circumference; and will resemble sparks of fire that incessantly succeed each other. The same effect will be produced by the star, or by any other figure, where the fire is not to appear as proceeding from the circumference to the centre.
These two pieces, as well as those that follow, may be of any size, provided we observe the proportion between the parts of the figure and the spiral, which must be wider in large figures than in small. If the sun, for example, have from six to twelve inches diameter, the width of the strokes that form the spiral need not be more than one-twentieth part of an inch, and the spaces between them that form the transparent parts, about two-tenths of an inch. If the sun be two feet in diameter, the strokes should be one-eighth of an inch, and the space between, one quarter of an inch; and if the figure be six feet in diameter, the strokes should be one-fourth of an inch, and the spaces, five-twelfths of an inch. These pieces have a pleasing effect, when represented of a small size; but the deception is more striking when they are of larger dimensions.
It will be proper to place these pieces, when of a small size, in a box quite close on every side, that none of the light may be diffused in the chamber; for which purpose it will be convenient to have a tin door behind the box, to which the candlesticks may be soldered, and the candles more easily lighted.
The several figures cut out should be placed in frames, that they may be put alternately in a groove in the forepart of the box, or there may be two grooves, that the second piece may be put in before the first is taken out.
The wheel must be carefully concealed from the eye of the spectator. Where there is an opportunity of representing these artificial fires by a hole in the partition, they will doubtless have a much more striking effect, as the spectator cannot then conjecture by what means they are produced.
It is easy to conceive, that, by extending this method, wheels may be constructed with three or four spirals, to which may be given different directions. It is manifest, also, that, on the same principle, a great variety of transparent figures may be contrived, which may be all placed before the same spiral lines.
In representing cascades of fire, it is necessary to observe, that, in cutting out the cascades, care must be taken to preserve a natural inequality in the parts cut out; for if to save time, all the holes are made with the same pointed tool, the uniformity of the parts will produce a disagreeable effect.
To produce the apparent motion of these cascades, instead of drawing a spiral, a slip of strong paper is to be provided, in which there must be made a great number of holes near each other, and made with pointed tools of different dimensions.
At each end of the paper, a part, of the same size with the cascade, must be left uncut; and towards those parts the holes must be made a greater distance from each other.
When the cascade that is cut out is placed before the scroll of paper just mentioned, and it is entirely wound upon the roller, the part of the paper that is then between, being quite opaque, no part of the cascade will be visible; but, as the wheel is turned gently and regularly round, the transparent part of the paper will give to the cascade the appearance of fire that descends in the same direction; and the illusion will be so strong, as to appear as a real cascade of fire.