These differ from other rockets only in the head, which contains a parachute for floating a coloured case, attached to the strings. The parachute is best formed of silk, or alpaca; it may also be made of black glazed lining, or of tissue paper, carefully rubbed, till the stiffness is removed. The colour should be dark, that it may be invisible. If of silk, or alpaca, the parachute may be 20 inches square, with 4 strings attached to the corners; or it may be made of 6 triangular pieces, sewed together, like an umbrella. If of tissue paper, the paper may be6⁄8of a circle, or6⁄8of an octagon, as fig. 97. The tissue paper must be strengthened with a piece of crochet cotton, running round the edge, as shown by the dotted lines, fig. 101. It is simply laid on, and the paper snipped at each corner, with the scissors, pasted, and turned back. The radius of the circle may be 15 inches.
For the lance, or colour, roll the case of 3 thicknesses of writing paper, on a5⁄8former: it may be 21⁄2or 3 inches long, and pasted all over. Turn a little wooden pulley, a, fig. 98, of a diameter to nearly fit the cylindrical head of the rocket; a hole in the centre of this pulley receives the colour; round the pulley, in the groove, lay a piece of chenille, fig. 100; twist the wires of the chenille 2 or 3 times together, and cut off flush. To charge the lance, set it on a flat surface, and drive in a film of meal powder, or shell fuse; then1⁄3of an inch of crimson star composition;1⁄3of an inch of green, &c., till nearly full; stop the end with plaster of paris, pressed in flat, with a knife. Paste a strip of paper round the mouth, so as to overhang not more than1⁄8of an inch; lay in two short pieces of match, one across the other, and tuck in, or pressdown, the pasted overhanging edges; this will keep the match from dropping out. Glue the pulley on, about midway of the case; envelope the end b with a bit of glazed lining. Take a piece of string, fig. 99; bring the ends together, and tie in a knot. Insert the knot in the envelope, and tie round above it, as at fig. 100, leaving the loop out, to which to attach the strings of the parachute. Let the strings be 2 feet long: fasten them to the loop; gather them together; wind them round the colour, above the pulley; fold the parachute neatly, and bring the edges down over the strings, nearly to reach the pulley: this will keep the parachute a little open, and help it to expand. Both the tissue paper and the glazed lining should be well rubbed, to get the stiffness out of them. To ascertain how a parachute will act, the learner can take the colour case, and stop one end with plaster, fill up with sand, and stop the other end with plaster. Fire it in the day time. Silk, alpaca, and glazed lining parachutes I can vouch for; tissue paper I have never tried, but am told it answers if it has not remained folded so long as to get set.
Between the top of the rocket and the mouth of the colour is to be a little pad of grain powder. Make a little square or circular paper bag with double-crown, and having put in the grain, and made the joining secure, smear both sides in the usual way, and sift dry meal over. If the rocket is to be fired at home, the parachute may be put into a long cylindrical paper bag, and left quite open at the top; but if intended to be carried to a distance, a thin bung may be put in at top, or a piece of turned wood: or a thin piece of paper may be pasted on it. In this case, be careful that it does not get stuck to the parachute.
Instead of the cylindrical head and the chenilled pulley, the head, fig. 39, may be used; and the protecting power from the fire to the strings supplied by putting a quantity of bran or sawdust. The cone must be held on, with not more than two thicknesses of double-crown.
Fig. 108. A triangular: 3 wheel cases and a case colour, at a. These cases are tied either to a hexagonal piece of deal board, or to three spokes, radiating from a nave. The colour is sometimes tied to a nail, driven in to receive it; or, it may be fixed on to a little peg. The peg is shown, by the side, at b. It is turned with a tenon, c; this tenon is glued in a hole, bored in the spoke; the part b may be half an inch in length; through it bore a small hole; charge the case colour on a foot, that enters the case half-an-inch; this void fits on to the peg b; pierce the case, through the hole in the peg, with a bradawl; push a bit of binding wire through, and twist. This is a far better way than tying it to a nail, as it cannot drop off. If the colour gets blown off, as it often does when tied, the piece is half spoilt. The colour may either stand at right angles, so as to face the spectator; or it may be fixed so as to lie in a plane with the wheel cases, very slightly sloping upwards; the mouth of the colour should point the same way as the mouth of the cases; if it wereplaced in the opposite direction, it would meet the current of air, be blown back upon itself, and burn the case rapidly. With respect to the wheel cases, it is obvious that the mouths must all point in the same direction; the slightest consideration would suggest this; it is necessary, therefore, to have some certain rule of proceeding, so as to avoid mistakes. Now supposing, for the mere sake of illustration, if you had a case in your hand, it were to take fire, you would naturally wish the fire to be directedfromyou. Let this, then, be the guide. You are about to tie the cases on a wheel. Sit, to do so; take the wheel between your knees: place a case upon it, with the choke endfromyou; tie, near the choke, also near the end; turn the wheel, place another case upon it, choke endfromyou; and so forth. Without this certain way of proceeding, you would be very embarrassed with the 12 cases on fig. 112; but, by attending to it, not the slightest difficulty will be experienced. Some of the cases will point obliquely upwards; some downwards; but they will all pointfromyou. In the end of the last case, as at x, fig. 108, put a little dryclay, to prevent a stray spark igniting it, and tie the envelope; or, tuck in the envelope, like as with an ounce of tobacco. Avoid every source of failure. Even the knots of the strings, with which the cases are tied on, are apt to come undone; they should either be touched with a dab of glue, or have a piece of paper pasted over them.
Fig. 109. A double triangular: 3 cases tied to the spokes; 3 to the previous 3. Double triangular frames are also made, with 6 spokes, on a long nave, 3 behind 3.
Fig. 110. A vertical wheel, illuminated. This is a wheel, with spokes, and a rim, or felly. The wooden hoops of the toyshops will furnish the latter. The illumination, as it is called, is made by lances, nailed with1⁄2inch Flemish tacks to the nave. The lances should be of different colours, but they ought, as nearly as possible, to keep time with each other. To effect this, it is necessary previously to adjust them; thus. Charge a number of cases, exactly two inches long, with different colours; use the same scoop to all, and give each the same number of blows, that they may be rammed as uniformly as possible.Fasten a string to the end of a leaden bullet, and tie a loop at the other end of the string. Let the length from the top of the bullet to the top of the loop be 39 inches. Suspend this from something, and set it swinging. Light the lances, one after another, and count the number of oscillations each endures. Keep a list of these, and write against them 10, 12, &c., or 5 per inch, 6 per inch. The bullet will indicate seconds, with the length of string recommended; and it matters not whether you give it a start of 6 inches, or 12 inches; for, if it goes twice as far, it goes twice as fast, so that the swings isochronise; the inestimable discovery of Galileo, which led to the invention of the pendulum. In order that the lances may be nailed on, they should be charged upside down, and left with1⁄2an inch vacancy; they can then be pinched flat, to receive the tack. Scrape out a little from the other end, and prime with very slightly damped meal.
Fig. 111. A rainbow wheel. This is a vertical wheel, generally with 3 colours, as drawn; the tail of the second, or mouth of the third, lights a; the mouth of the fourth, band c; but any arrangement may be made. Place the colours, red, green, blue, at different distances from the centre, so as to form rings, equidistant, when burning. Suppose the spoke 12 inches long; place the colours at 3, 6, and 9 inches from the centre. It receives its name from its resemblance to the rainbow.
Fig. 112. A caprice, or furilona, according to the number of the cases. A caprice, from the capricious manner in which it turns, up, down, and round about, now this way, now that. A furilona, possibly, from the fury with which it plays, when 4 cases are burning together, at the end: though some call it a fruiloni, said to be from the name of its inventor. A furilona and caprice wheel are much the same; the former, generally, has fewer cases on it than the latter. A coloured gerbe, placed on the top, is very effective; or, it may have a mine, or jack-in-the-box. The cases are to be placed so that some of them play horizontally, some obliquely upwards, some obliquely downwards; the spokes, which are concave at the end, are glued in, so as to determine the slope of the cases. If there are 10 cases, they may befired thus, h, u, d, hud, hudp; that is, 1 horizontal, 1 up, 1 down; 3 at once, horizontal, up, down; 4 at once, horizontal, up, down, perpendicular. If 13 cases, thus: h, u, d, hu, hd, ud, hudp. While tying the cases on the frame, it should be on a short wire, held perpendicularly in a vice, or block of wood; properly, the wire should be tapering, so that the frame should bite, when dropped on; the tapering will allow it to be turned round, easily, by slightly lifting it. Let the leaders be drawn straight, and not left dangling in curves, nor crossing each other. There must beenoughmatch, but there ought to be no more. Look well to the mouths and tails of the cases; it is best to put a piece of pasted paper over each, for as the piece dashes round with great violence, if a stray spark falls on any composition filtering out, the whole is spoilt.
Fig. 113. A horizontal wheel, with mine and roman candles; the cases on the wheel are to be tied so that some play horizontally; some, obliquely upwards; some, obliquely downwards. To make a case play thus, tie it on the wheel, across the middle of the case;this being done, turn the mouth upwards or downwards, and tie it again, making the strings cross the previous ones, so as to form a letter X.
Fig. 114. A turning sun: two concentric hoops nailed to spokes, or a frame; the cases lying on the hoops, slope; 3 or 4 may light at once; the spokes carry triangular, or vertical wheels; at the centre is a double triangular, or larger vertical.
Fig. 115. A rayonant star piece: a wheel with six spokes; at the end of each spoke, two fixed cases, forming a V, the alternate spokes carrying saxons; at the centre, a double triangular, half-way between the triangles and the saxons, six five-pointed stars. A very beautiful piece.
Fig. 116. A chequer-piece: a true-lover's-knot in the middle, 16 fixed cases, 4 on each side the true-lover's-knot; and 4 saxons at the extremities. The fires cross, and chequer into squares.
Fig. 117. A scroll wheel: six or more cases on the wheel, to play in pairs; lances arranged on cane or hooping to form a scroll as indicated.
Fig. 118. A pyramidical piece: a scroll wheel in the middle; five horizontal wheels, or triangulars, at intervals, as represented by the rings; brilliant fixed cases playing obliquely upwards: at the bottom may be a row of cases playing downwards; these form what is called a cascade. Gerbes make the most effective cascades, but they require to be placed at a great height from the ground, if containing iron: the coke grains will be found suited for 8 or 10 feet.
Fig. 119. A spiral wheel: six cases on a horizontal wheel; lances arranged in a spiral, on cane, or hooping.
Fig. 120. A true-lover's-knot: six6⁄8wheel cases, playing in pairs; three saxons, one carrying a blue; one, a green; one, a crimson colour. Light at a; this leader blows across, and lights the opposite starting case. The tail of this case lights the saxons: the ends of the saxons at c, c, c, before enveloping them, are to be smeared with meal; the end, b, is also to be smeared with wetted meal, to insure the ignition of the leader. This is a most beautiful piece: the colours, on the saxons, form loops, and represent, in a slight degree, thecompound motions of the moon and planets, with regard to the earth. The centres of the saxons are carried round in a circle, like the earth in her orbit; the colours on the saxons revolve round the flying centres, like the moon round the earth. The wheel must not be less than 3 feet diameter.
Fig. 121. A revolving globe. This is, also, a most beautiful piece. The bottom is a horizontal wheel, carrying a strong half hoop, a b c; a skeleton globe, formed with hoops, is suspended in this. This globe is driven by cases placed upon it, round a hoop, crossing the other hoops, at right angles, like the equator, at right angles to the meridians. The meridional hoops are covered with lances, white or coloured. The globe revolves vertically, while the wheel below turns it horizontally; the compound motion produces a peculiar oblique tumbling convolution, exceedingly perplexing to spectators, ignorant of its construction. Instead of a globe, the top piece may be a revolving cylinder.
Fig. 122. A mine. This is a cylindrical case, containing serpents. The bottom of the mine should be a circular piece of wood,glued in. On it, place a circular bag, containing F grain powder. The bag is made with two circular pieces of paper, one half-an-inch diameter larger than the other; lay the small one on the top of the large one: paste, or gum, the exposed rim of the bottom piece, and bend it up, and press it down on the small or top piece, all round, leaving a part through which to put the powder; when dry, put in the powder, and stop up the hole. Put it into the mine, smear it with the brush, dipped into meal paste, in the usual way; and, with a pepper-box, shake in a little dry meal. Take a fixed case, charged; envelop it, so that the paper projects about an inch at the bottom: take a piece of squib-case, the same length as the serpents; put through it a piece of match, long enough to protrude at the top, half-an-inch, and to bend over, to form a hook: tie this in the envelope of the fixed case. Fill the mine with serpents, naked primed mouth downwards: with the scissors, or a pair of pliers, draw out the middle serpent; put in the matched squib-case; hold the fixed case upright, in the mine, and ram pieces of torn paper tight round it, to offerresistance, and cause the serpents to be blown higher. To adjust the blowing powder in the bag, use the following formula, I denoting the diameter in inches.
I x 2I = drams.
Required the quantity of powder for a mine 11⁄2inch diameter.
11⁄2x 3 = 41⁄2drams =1⁄4oz.
For 13⁄4inches?—13⁄4x 31⁄2=7⁄4x7⁄2=49⁄8= 61⁄8drams =3⁄8oz.
For 2 inches?—2 x 4 = 8 drams =1⁄2oz.
For 21⁄2inches?—21⁄2x 5 = 121⁄2drams =3⁄4oz.
For 3 inches?—3 x 6 = 18 drams = 11⁄8oz.
It is by no means necessary to be exact; but the formula will serve as a guide.
Fig. 123. A jack-in-the-box. This is a case formed on a square prism of wood. The paper is to be pasted all over, but as it cannot be rolled, it must be folded over, one side at a time, and rubbed smooth with a tooth-brush handle, or pressed with the fingers. The bottom may be formed by bending in, to a right angle, two opposite sides, and pressing them flat; then, upon them, the two remaining sides, like packets of cocoa, &c. Ora square piece of wood may be glued in for a bottom. The same blowing charge as for mines.
Fig. 124. A devil-among-the-tailors: a mixture of crackers and serpents; a roman candle in the middle, having its bottom stopped with shell fuse, instead of plaster of paris: 3, or 4, or any number of roman candles, at regular distances, round the outside: these are to be tied with string, and a strip of pasted paper fastened round.
Fig. 125. A line-rocket: two rockets tied to a piece of roman candle case, head to tail: that is, one rocket tied in one direction, the other, in the reverse. This simply runs up and down a line.
Fig. 126. A pigeon frame (of which fig. 127 is a cross section) may be made by taking a piece of deal, or alder, say 6 inches long, and 11⁄2inch square: bore a hole through the length to receive the line upon which it is to run; plane off the corners, lengthwise, and channel them with a gouge, to form 4 semi-cylinders for the rockets to lie in: in the middle glue 4 spokes, each about 4 inches long; and round the spokes nail a wheel. A piece of canemakes good spokes, light and strong. Tie on the frame, lying in the channels, four6⁄8rockets, two pointing one way; two, the other: the clay or plaster of paris, in these rockets, is not to have a hole through it, as usual, but to remain perfectly closed. On the wheel, tie four5⁄8wheel cases, charged with wheel case fuse, No. 1 or No. 10. Leader it thus: touchpaper the mouth of one wheel case. From the tail of this first wheel case, carry two leaders; one to the next wheel case, and one to the rocket whose mouth is nearest: the tail of the second wheel case lights the third wheel case and second rocket; and so on. A long clothes line must be stretched tight for this to run along; it should start 3 or 4 yards, at least, from the post to which the line is tied: and the rope should be so long that the first rocket could not carry it to the end; otherwise the leaders are apt to snap and spoil the piece. Towards the end, as the piece gets lighter, it will run the whole length of the rope, without injury. It is necessary to indicate the first, or starting rocket, by some means; a piece of red paper may be pasted round the mouth; or, an inch or two of stringmay be tied to it; or the match may be bent and tied so as to project an inch or two longer than the others. On fixing it on the line, in the dark, you can then feel which is the starting rocket, and place its mouthtowardsthe starting post, without hesitation. Of course the pigeon runs away in the opposite direction.
Fig. 128. A pigeon-house, made with lances; this may be fixed in a central position, and have 4 lines running from it: east, west, north, and south. As soon as the lances are well alight, start the pigeons. This is not necessary for amateurs. One pigeon is sufficient, without any pigeon-house.
The piece, fired at the Crystal Palace, termed a comet, is a combination of the pigeon, fig. 126, and the turning sun, fig. 114. Construct a pigeon frame, with two hoops, one at each end; to these hoops, attach brilliant cases, or gerbes, placed obliquely: point the mouths of all the rockets and gerbes in the same direction. The whole of the cases may be lit at once; or a short case may fire the rockets after the piece has partly descended the line, by its own weight.The line, at the Crystal Palace, is stretched from the top of the northern tower to the ground.
Fig. 129. A double guilloché, or windmill piece. This represents two windmills, turning in opposite directions; and imitates the engine turning, on the backs of watches.
Fig. 130. A five-pointed star. This has been already described.
It is desirable, sometimes, to convey the fire from a movable or rotating piece, to a fixed, or second rotating piece, which is effected thus. A leader, a, fig. 131, comes from the tail of the last case of the first rotating piece. This leader is tied, in one or more places, to one of the spokes of the wheel, and to the nave; and is left protruding at b. A tin box, or a bit of a mine case, d e f g, is attached to the fixed, or second movable piece in such a manner, as to surround, but stand clear of, the end of the match, b, as it revolves, with the wheel. A hole is made at c, and the end of a leader, from the second piece, brought through it. The inside surface of the box, d e f g, is smeared with meal-paste. When the leader catches at a, it blows through to b;this lights the smeared surface of the box; the flash communicates the fire to c, and this carries it where desired.
Sometimes a piece is made to drop, which is thus effected. Suppose a cylindrical piece of iron, 6 inches long, 3 inches diameter, standing upright; on this a second cylinder, 12 inches long, 2 inches diameter; and, on this, a third cylinder, 2 inches long, and 1 inch diameter. If now a brass ring 11⁄4or 11⁄2inches diameter be put on the top, it will slip down, and rest on the 2-inch cylinder; if a ring 21⁄2inches diameter be slipped over the top, it will fall, and rest on the bottom 3-inch cylinder. It is obvious that, if a horizontal wheel, having a hole in the nave, 21⁄2inches diameter, be slipped on, it will drop, and rest on the bottom cylinder; and that a second wheel, with a 11⁄2inch hole in the nave, will rest on the second cylinder. The two wheels, then, may be placed on, and held together with a piece of thickly leadered match; the top wheel plays for a while, and carries the second wheel with it; the tail of the first, or other case, lights the bottom wheel, and at the same time blows the match to pieces, and the wheel drops.Of course three or more wheels may drop, one after another. See the design, fig. 166.
Sometimes a horizontal motion is changed to a vertical, thus. Suppose an upright wooden post, 3 inches square. Saw off the top 18 inches, and fix it on again, with a hinge; drive a staple, on the other side, into the top piece; also one into the bottom piece; and connect the staples with a piece of string, to prevent the top piece falling. In the top drive a spindle, as usual, to receive a horizontal wheel. On the side of the fixed post, against the hinge, fasten an iron bracket, to stand forward, so that the top part, when the string is cut, can fall down, and rest on the bracket. Now slip over the spindle a brass tube, 3 inches long, and almost a fit; then put on it a horizontal wheel, carrying a smeared box, as above described, to convey the fire to a fixed piece; on the top of the spindle screw a nut. To the bottom post, tie a piece of shell fuse, and let the string, that prevents the top piece from falling, be drawn over the mouth of this, and secured. It is obvious that if, after the wheel has played awhile horizontally, the shell fuse is litby a leader, the string will be burnt in two; the top part will fall on to the bracket; and the horizontal motion will be changed to a vertical one.
Roman candles are best fired in bouquets of three or more; connect them with leaders about 3 inches long; and set them in a block of wood, containing three or more holes, diverging right and left; or tie them to struts of wood, nailed together, like the supports for garden flowers.
Two vertical wheels may be made to run round the outside of a table, to imitate the motion of the machine for grinding drugs, crushing clay, &c., like two parallel grindstones going round in a circular trough. Conceive a circular table, 20 inches diameter. With a gimlet bore a hole in the centre, large enough to admit a screw-eye, with liberty to turn easily round; slip through it a stair-rod, 2 feet long; it will overhang 2 inches at each end, and may be swung round. At the distance of about 4 inches from each end of the rod, imagine a cotton reel, or a pulley; when the rod is moved round, the reels or pulleys will roll round in a circle, like the cylinder-crushers, above mentioned. Now, if a vertical wheel were fixed at each end of the rod, so as to hang outside the table, it is obvious that, upon firing it, the wheels would run round. Of course it must not be a screw-eye and a stair-rod; but anyone will understand, from this description, how to effect it.
These contrivances have fallen somewhat into disuse, since the introduction and variety of colours, but it is well to understand them.
Suppose a cubical tea-chest. In the top, bore ten rows of holes, ten in a row, with a centre-bit; the same in the bottom, in such a way that the bottom holes fall perpendicularly under the top holes. Fasten the box upon four legs, one at each corner. Sift from a pepper-box a layer of meal powder over the top; put in the rockets, with their primed mouths, naked, to rest on the sifted meal. It is evident that, upon conveying fire to the meal, by a leader, the flash will ignite the whole of the rockets, at once. Of course it ought not to be a tea-chest, but a box constructed on purpose, with a penthouse lid, tofall over, and protect the rockets, till desired to be fired. It may be furnished with four legs, as in fig. 173. The shelf, fig. 172, fits in at a b c, fig. 173.
Fig. 132. A port-fire holder. This is made of steel, somewhat after the manner of a pair of pliers. The ends a and b are fluted, or channelled (semi-cylindrical) to receive the port-fire: a spring, riveted at c, holds it tight; by pressing on d, the burnt case drops: the end e is pointed, to enter a long stick, bored to receive it, and strengthened with a brass ferrule.
As an instrument of this kind can be obtained only when made to order, the following contrivance will serve the purpose of most amateurs. First charge some little port-fires, 3 inches long and1⁄4inch diameter, till within about 11⁄4inch full: having filled a couple of dozen, or so, invert them, and knock out the dust, as with squibs; then encircle the whole, as if going to bang them; but pour in dry sand instead; empty a little sand from each, and stop the end with plaster of paris.Scrape out a little composition from the other end, and prime it with damped meal. Take two inches of a roman candle case, or a piece of turned wood, with a hole through it, fig. 133, two inches long. Have a long stick, fig. 134; cut the end, a, so that it will fit the hole in fig. 133, and enter half way up. At the other end fix a wire, z, two and a half inches long. By slipping fig. 133 on fig. 134 it is evident one inch vacancy is left to receive the sand end of the port-fire; when this is burnt out, it can be pushed out with the wire, z.
The numerous formulæ for coloured fires, renders the use of very small scales excessively troublesome; and there is perpetual danger of losing the little weights for grains and pennyweights. By constructing a steelyard scale, the greatest facility is attained, one weight answering for all.
Take a piece of deal, fig. 135, about as thick as a venetian-blind lath; it may be 20 or 24 inches long; an inch broad, at the leftend; and about1⁄2an inch broad in the main length. Make a hole at a, twice the diameter of a pin: the same at b. It is necessary to observe that the hole, a, must be on a level with the top of the long arm; if it should be a little higher, it would not be of any consequence; but it must, on no account, be lower. Have a piece of deal, fig. 136, about an inch square, and mortise a hole in it, as drawn. Fix 135 in 136 so as to appear like 137. A bit of a common pin, or needle, is to go through the mortise and through the hole, a, of 135. See that it plays easily. At s, fig. 137, insert a piece of wire, bent like the figure 8; and to it, tie the strings fastened to w, which may be a copper bowl, or a tin patty-pan. The mode of fastening the threads to the figure of 8 wire, is simply to slip them through, bend them down, and tie round with thread, as at z.
Take a piece of brass tube, an inch, or so, long, fig. 138, and with some lead, melted in the bowl of a pipe, fix a bit of wire in it, bent like a staple, or the capital letter U, as drawn. This is for a weight. Slip it on the arm of fig. 137; put a wooden pin in the hole y, tokeep the weight from falling off. Slip the weight along, till it balances the patty-pan w: suppose this point is at m. This will be the starting-point. From m to y lay off a number of equal distances, as eighths of an inch. Number them, and the scale is complete. If it be desired that 100 of these divisions should weigh 1 ounce, an ounce weight must be put in the patty-pan w, and the weight shifted along, until it balances; the intervening space must, then, be divided into 100 equal parts. It is desirable to construct two; one with a large weight, that will weigh 8 or 10 ounces; one with a small weight, to weigh the1⁄100th part of an ounce. This may be of wood, with a wire staple, about the thickness of a patent short-white pin. Nothing can be more convenient than these steelyard scales, as one weight answers for all, and never drops, and gets lost. It is well to have even a third steelyard scale. This may be made very thin, with a piece of wire, bent to the shape of fig. 171, for a weight. It may be made to weigh only the fifth part of an ounce; so that if divided into 100 equal parts, it will weigh the1⁄500th part of an ounce; so that intrying a new colour, as little can be mixed as will charge only one or two pill-boxes. A little notch should be made, at every division, with a fine, triangular file, to prevent the weight from slipping: every tenth division can be numbered; this is best done with a blacklead pencil, as ink runs; and on the end s, fig. 137, mark how many to the ounce. Possibly the trade, if desired, would make them to order. There is an instrument, somewhat similar, the chondrometer, for estimating the quality of grain; only this is constructed upon the principle of the log; the leverage and counterpoise showing the weight of a pint, but indicating that of a bushel; as the half-minute sand-glass times the running out of the knots of the line, and indicates nautical miles. Goods-weighing-machines, at the railways, are on the steelyard, or shifting leverage principle; also the machines warranted to furnish you with "your correct weight."
To project a pattern gore. With a radius of 5 inches, fig. 139, from the point a, on the line b o, describe a semicircle; divide the upper quadrant into three equal parts, in the points g, e, c. Carry the same distance, once down, to k. Draw the lines f g, d e, a c, h k, parallel to each other, and at right angles to the line b o. Draw the line a k, and prolong it to s, so that the distance k s shall be 10 inches,viz., twice the radius. From s, with the radius s k of 10 inches, describe the arc k n p. Draw o s parallel to h k; and, halfway between, m n.
As the distance from a to c is 5 inches, twice this will be 10, for the equatorial breadth of the gore; and, as it is intended to have 12 sheets of tissue paper (3 of each colour, yellow, blue, green, and red), and, consequently, 12 gores, 12 times 10 = 120, the half of which is 60, for the semi-circumference. Tissue paper is a very thin double-crown, 30 by 20. Lay down a straight line, b x, fig. 140, 60 inches in length, and divideit into 6 parts of 10 inches each; and draw parallels f g, d e, &c., at right angles to the meridian line b x. Measure the distance f g, fig. 139, and make f g, fig. 140, twice as much, half on each side; the same with d e, &c. Draw lines, connecting the extremities, till the fig. 140 is complete.
Instead of taking the trouble to construct fig. 139 with the compasses, the following measures will describe the pattern gore, fig. 140, at once; f g will be 5 inches, half to the left, half to the right, of the line b x; d e = 82⁄3inches; a c = 10 inches; h k = 82⁄3inches; m n = 7 inches; and o p = 63⁄4inches.
These numbers are chosen to suit the size of the paper, to get the gores as large as possible, with the least waste: 60 inches are selected as the length of the gore, being twice the length of a sheet; 10 inches are1⁄6the length, and exactly half the breadth of the sheet; so the length and breadth are both employed, without the slightest waste.
The pattern gore should be of cartridge or imperial brown.
Lay the twelve sheets of tissue paper flat upon each other, as at fig. 141; cut the pattern gore into two pieces, along the line a c, fig. 140, and lay them on the tissue paper, fig. 141. Mark round them with a blacklead pencil, and cut them through with a strong pair of scissors.
Lay the bottom part of the gore, fig. 142, flat upon the table, and the top part upon it, so as to leave1⁄4of an inch along the edge exposed, as shown by the shaded part. Paste this; and, without removing either piece, bend the pasted part of the lower half gore upon the top, and press it smooth down.
Lay one gore with the point towards thelefthand, and another upon it, a quarter of an inch back, as in fig. 143. Paste the shaded part of the lower gore, bend it over, and press as before. One of the gores, having been drawn in by pasting, is now narrower than the other. Finish the six pairs, and lay them by to dry.
Lay one pair with the points towards therighthand, thus keeping the widest gore upwards; and another upon it, in the same manner, as fig. 144. Bend the top gore back upon itself, by folding it down the middle, as shown by the bottom shaded part, and lay a book or weight upon it, to keep it out of the way; paste, and double, as before; and so proceed, till the whole twelve are finished, and lying upon each other. Be careful to disturb none of the gores.
Turn the points towards thelefthand: lift up the top, and bend the ten inner gores back upon themselves: draw the top gore over, so as to make it lie upon the bottom. Paste as before. This is a somewhat troublesome operation, and it is advisable to have the assistance of a second person.
Select a coil of iron wire, a little thicker than a pin; and remove the elasticity, as recommended with coloured gerbes. Beforeapplying it to the balloon, practise the method of making a joining, as shown by fig. 145, simply bringing the ends together, crossing them about an inch from the extremity, and winding them tight round each other. Now lay the balloon, as in fig. 146, with a book, or a flat weight, upon it, to keep it down: curve the wire to the shape of the bottom of the balloon, and lay it about half an inch from the edge. Notch the paper, at the joinings of the gores; paste, and fold back. When perfectly dry, not before, turn the balloon over: cut the wire 2 inches longer than to meet; bend the ends together, and make the joining; paste, and bend over, the remaining half; and shape the wire to a circle. A star, of double-crown, may be pasted on the top, and a thread passed through it, to hold it by. To effect this, open the balloon, pass a book up it, spread the top flat on the book, and paste on it a star, or a circular piece of paper, the size of a penny. If a hole gets torn in it, it can be repaired in the same way.
Take two straight pieces of wire, a little longer than the diameter of the mouth of theballoon; pass them, half way, through a piece of sponge, at right angles to each other; fasten these wires across the mouth; saturate the sponge with wood naphtha, or methylated spirit, taking especial care that not a drop falls on the balloon; get someone to set fire to some pieces of paper on the ground; hold the balloon at a good height above the flame, to prevent the spirit, in the sponge, from catching. Three persons ought to assist in the start: one to manage the burning paper; two to hold the balloon steady, and to keep the mouth open, for the hot air to inflate it. As soon as the balloon gets expanded, set fire to the spirit; and directly it begins to pull against the hand, which it will do, let it go. A balloon of this size will require an ounce of spirit, and as much sponge as will absorb it. See fig. 167.
To project a gore for 24 sheets of tissue paper, let the radius be 71⁄2inches; for 48 sheets, 10 inches. The shape of the balloon, when expanded, will be the same as fig. 139, rotating on the axis b o. If the pattern gore be projected from fig. 147, the balloon will be pear-shaped, and may be filled with gas,like those started from the Crystal Palace. The paper, 16-lb. double-crown, must have a coat of boiled linseed oil. The bottom should be open, and fitted with a cylindrical neck, about an inch diameter, and 3 inches long, made of writing paper of three thicknesses. Fig. 168 shows the magnesium light attached.
A flat weight may be constructed by making a thin deal box, the size and shape of a lucifer-match box; fill it with melted lead; nail a lid on it, and cover it with pasted paper. The same will serve for a paper-weight.
A spindle, on which to fire wheels, is shown at fig. 148; it is furnished with a fly-nut, which can be taken off, and put on, without trouble. As there is considerable difficulty in obtaining an article of this kind, its place may be supplied by a carriage-bolt, of which hundreds, if necessary, may be procured at the ironmonger's, of lengths varying from 1 inch to 12, or more. One of 6 inches will be suitable for most purposes. As the nut is small, and would be difficult to find, if dropped on the ground, on a dark night, proceed as follows. Turn a piece of beech, about 11⁄2inch square,and 21⁄2inches long, into a cylinder, with hemispherical ends, and a hole through it, like a popgun. Cut it, while yet in the lathe, or saw it across into two pieces, one an inch long, the other, an inch and a half. In the flat end of the inch length, mortise a hole, and sink the nut in it; take a circular piece of wood, with a hole bored in the middle, and screw it flat on, over the nut. Fig. 150, a, shows the turned piece; b, the circular piece, screwed on, to keep the nut from falling out. This serves the purpose of the fly-nut of fig. 148. The carriage-bolt is shown, first at fig. 149; then at fig. 150, with the nut screwed on. Take a piece of deal, fig. 155, about 11⁄2inch square, and 20 inches long: make a hole through at a, and drive the carriage-bolt from behind; the shoulder, being square, will hold firm; in front, at c, slip on the above turned piece of wood, an inch and a half long: the piece, with the nut embedded in it, is, of course, put on at the end, b. The hole through this inch piece should be1⁄8of an inch, or more, larger in diameter than the female (or counter) screw of the nut, in order that it may slip on and off with ease. Atthe top fix a strong wire, d, and file the end round and smooth: at s and x, in the side, fix two screw-eyes, or staples, to receive rocket sticks. At m and n bore two holes, through which it can be screwed to a post. The screw-eye at s ought to be about level with the top of the post. If there is too great a space between w and z, pieces of a roman candle case may be slipped on; but a popgun, sawed into short lengths, is better. Several should be kept in readiness, of different lengths, to suit the naves of different wheels. A piece of iron rod, about half an inch long, and to fit the hole, ought to be driven up furilonas, &c., to rest on the top of d, fig. 155; and the wire should be a little longer than the hole, that the piece may play clear of the upright, the top of which should be hemispherical, as drawn. Fig. 151 is a screw-ring; 152, a screw-eye: 153, a screw-hook; 154, a cup-hook. If a little bit, s, of 152 be sawed, or filed out, it makes a stronger cup-hook than the brass, for match-weights.
An8⁄8rocket is the smallest size worth making: it is, also, sufficiently large; and, as it requires a machine to fire it from, it is best to keep to one size. The head, fig. 156, may be the same as the external diameter of the case, or it may be slightly enlarged: to receive a parachute, it may be 12, or even 16 inches high; and the top may be closed with a lid, fig. 163, formed of a case choked tight; or by simply stopping it with a piece of turned wood, or with a thin bung, pushed in, as a cork into a bottle. A bung may be readily sawed thin with a fine-toothed saw; if required to be made smaller in diameter, it must be cut round sidewise, not longitudinally. If the head is to receive stars, it must not be above 8 inches high. To construct the wings, take a thin piece of deal, or tin, and cut out a right-angled triangle, fig. 157. Make a b = 71⁄2inches, b c = 11⁄2inch. Take a piece of imperial brown paper, 8 inches long, 4 broad, and fold it down the middle lengthwise, so as to become 8 by 2. Lay the sloping edge, a c,of fig. 157 along the folded edge of the paper, a c, fig. 158, and mark round it, with a pencil. About3⁄8of an inch distant, draw the line d e parallel to a b. Cut through with the scissors, and the paper will be of the shape of fig. 158. Bend the shaded parts flat, to form a flap, or kind of hinge. Paste the surface of the two triangles, and press them together to form a double thickness. If this does not make the wing stiff enough, insert, between them, a triangular piece of cardboard, to make it of three folds, like a shirt-collar. Take a piece of sheet tin, or a piece of cardboard, fig. 161. Let m n be 7 inches; and m p such that it shall exactly wind round the rocket. Divide it into 3 equal parts, by the parallel lines r and s, and at each end cut out little pieces, as shown at a a, &c. Now, if this be wound round the rocket, marks can be made through the slits a a, with a blacklead pencil, or with a stencil-brush, dipped into blacklead powder, such as used for polishing grates. These marks will indicate the places for the wings. Paste or glue them on, and secure the joinings with another slip of paper pasted over them, as shown by the dotted lines, beside the wings,fig. 156. The wings will branch out at angles of 120° divergence from each other, like the lines a a, b b, c c, fig. 162. The rocket is thus winged; and, so far, complete.
Procure 3 pieces of planed deal,1⁄2an inch thick, 2 inches broad: let one piece be 6 feet 3 inches long; the other two, each 6 feet. Get a smith to make 4 triangular iron holdfasts, k m n, fig. 162, 5 inches along each side; the iron may be a trifle above1⁄8of an inch thick, and6⁄8broad: in each side, let two holes be made, as in the usual holdfasts, to receive screws. The screws are represented at z z, fig. 162, which is a cross section of the tube. Fasten the 4 iron holdfasts round the 3 pieces of deal, as represented by w w, fig. 160, at equal distances. The pieces of wood will thus form a triangular spout, with open corners. The pieces are to be level at the top; the longest one, of 6ft. 3in., will, thus, be 3 inches below the other two, as at r r, fig. 160. At s s bore two holes, about1⁄8of an inch diameter. Take a small piece of deal, fig. 159, and fix in it two pieces of wire, so as to have the appearance of a tuning-fork. These wires are to go through the holes s s, of fig. 160, to form a resting-place, or support for the rocket, after it has been pushed up the tube. At the top of one of the short pieces, is to be a hook, k, by which to suspend it from a post. This post ought to be 9 or 10 feet high, that the rocket may be fired without having to stoop. Everything being ready, the rocket is to be put up through the bottom of the tube, and the wires of fig. 159 pushed through, for it to rest upon. It may then be fired.
These rockets are peculiarly fitted for asteroids, as, from their lightness, they rise to great heights, with immense rapidity, not in a continuous curve, of uniform flexure, but with a sweeping serpentine motion, as indicated by the line, fig. 164. They might be employed, with great advantage, for distress rockets at sea.
They could also be made with four wings, and fired in volleys, from batteries constructed with square tubes. See the design, fig. 165.
Sublimation is the volatilization of solid substances by heat, and their crystallization by cold again into solids.
The products of sublimation (sublimates) have received the name of flowers from their soft efflorescence, or aggregation of minute spicular crystals into flakes; as flowers of sulphur, the crystallized refrigerated vapour of burning brimstone; flowers of benzoin, benzoic acid; corrosive sublimate, bichloride of mercury; sublimed arsenic, camphor, sal-ammoniac; vegetable and lamp black, the condensed fumes of burning oils and resins; soot, the flakes deposited in chimneys from the smoke of burnt wood and coals.
Distillation is the evaporation of liquid substances by heat, and their condensation by cold again into liquids.
The products of distillation (distillates) are usually termed spirits; as spirit of wine, alcohol or brandy; spirit of grain, gin, hollands, or whiskey; spirit of molasses, rum; spirit of naphtha; benzine, &c.
Water heated and cooled, combines in resemblance the effects of sublimation and distillation; aqueous vapour by congelation crystallizing into snow; and by condensation liquefying into water.
The condensation of steam into water is familiar to everyone. It is stated that in St. Petersburg, upon the sudden admission of a current of cold air into a crowded assembly-room, the vapour in the air was immediately congealed, and fell in the form of snow flakes. Probably snow might be produced artificially by driving steam into a vessel preparatively cooled below the freezing point.
Gums are the exudation of trees, vegetable mucilage thickened by exposure to the atmosphere; as gum from cherry and plum trees; gum arabic, from varieties of the acacia, Turkey, East India, Senegal, or Barbary; Turkey gum arabic is the best.
Resins are the exudation of trees, generally evergreens, essential oils inspissated by oxygenation: as mastic, sandarac, benzoin.
Gums are soluble in water; resins in alcohol and essential oils.
Gums dry and swell up by heat; resins soften and melt.
Gum resins are partly resinous and partly mucilaginous; as lac, assafœtida, galbanum. In submitting shellac to the action of alcohol, the whole is never entirely dissolved; as the lac contains, besides the resin, a mucilage which floats about in the liquid, and renders it turbid.
Many substances which go under the name of gums in commerce, are in reality resins or gum-resins.
Native turpentine, the juice of trees of the fir tribe, of the consistency of honey, yields on distillation spirit of turpentine, called also oil of turpentine, and by painters turps; the dry mass left behind in the retort is colophony or rosin. Rosin is soluble in alcohol, and is therefore a resin; rosin and resin, however, are not synonymous; all rosin is a resin; but all resins are not rosin. Rosin has been tried in pyrotechny, but is of no use: a solution of it in spirit will bind stars; but it renders them white and smoky.
Volatile, ethereal, or essential oils are obtained from plants by distillation withwater; as oil of roses, lavender, thyme, peppermint, aniseed, &c.
Fixed oils are obtained from animal fat by heat; and from seeds of plants by pressure and percussion; as, train oil, cod-liver oil; palm oil, croton, linseed, cottonseed, &c.
Oxychloride of copper, if difficult to procure, may be made by laying thin pieces of copper in a dish, and pouring upon them a mixture of half water, and half hydrochloric or muriatic acid. The next day remove them, and lay them on a board in the shade to dry. When dry, brush off the green powder which will be found on the outside, with a toothbrush, into a basin of water. After a quantity is obtained, wash it as directed for sulphur, and dry it in the bag, fig. 33. Test it with litmus paper to ascertain if free from acid.
Saw a piece of coke or charcoal in two, and on the flat surface place a few copper filings; direct upon them the flame of a lamp or candle with the blow-pipe; they will simply become red-hot. Lay a few more filings, and on them a little calomel or sal-ammoniac: now direct the flame, and a beautiful blue colour will be produced. Any of the salts of copper maybe used to obtain the same effect, the chlorine gas liberated from the calomel (chloride of mercury) or from the sal-ammoniac (ammonic chloride) giving a blue colour to all preparations of copper burnt in it.
Weights for quickmatch may be made by nearly filling the brass tube with useless rusty old nails, tacks, screws, or odd bits of iron, or brass; then pouring in melted lead. If the ladle will not hold enough lead to fill it at once, it may be poured in at twice, thrice, four or more times. A tube 11⁄4inch diameter and 6 inches long will weigh 21⁄2lb. This will keep a great length of match tight and straight. Half-an-inch at each end of the tube should be solid lead, one to receive the screw, and one to make a firm bottom.
If at any time the basil end of a pinwheel pipe should be too small to admit the nose of the funnel, it may be enlarged by binding a gum strip round it. If pinwheels are too dry, they break in winding, from the hardness of the composition; if too damp, from the softness of the paper. As paper cannot be relied upon for being always of uniform thickness, if it be found that a pinwheel pipe is too thin,cut the strip a little broader. Discretion may be used in all cases.
Coloured lances may be primed with meal powder very slightly damped with thin lac solution. Leader pipes may, if preferred, be fastened to lances with patent short whites: they may be procured at the haberdasher's; the price of them is 2d.per oz. Push the pin through the side of the leader, down into the side of the lance; then make a triangular hole through the middle of the leader, down into the middle of the lance, turning the tool round to break the priming, and secure the leader with a gum strip. The gum strip, bent round, assumes the shape of the capital letterT. The best tool for making the holes is a steel bradawl, ground triangular and to a sharp point; another bradawl ground to a tapering point like a needle, about3⁄4of an inch long, may be used for making holes up the lances to receive the wires. Scissor-grinders will shape them, if you have not a grindstone; or they may be rubbed on a stone, such as used by mowers to whet their scythes. Afterwards set them sharp on a hone.
Fig 169 is a wasp-light. The proper composition will be found among the fuses: drive it into a roman candle case with the rammer, fig. 4. Bring the leader from the mouth b, backwards along the outside of the case, and tie it in a couple of places, as drawn. Evening is the best time to use it: push the end b into the nest, light at a, and retire.
Instead of a five-pointed star, a seven-lance star, fig. 170, may be employed. To form it, have a piece of deal board, half-an-inch thick, 61⁄2inches square: draw the diagonals, to find the centre; and, with a pair of compasses, stretched to a 3-inch radius, describe a circle. Carry the radius 6 times round it; and in the points and the centre drive 7 French nails; cut off their heads, and fix on them 7 lances: the middle one, crimson; the others, 3 green and 3 blue, placed alternately.
In forming a rocket spindle, taper it no more than will just make it deliver: the thicker it is left at the top, the stronger of course it will be. For small rockets,3⁄8or4⁄8, a brass, iron, or steel wire, with a few notches filed in it, or made jagged with a cold chisel and hammer, driven into a block, will holdfirm without a screw. I have seen them driven into a piece of thick plank, and the nipple formed with an inch-length of wood, cut cylindrical, bored and slipped over the spindle, like c in fig. 155. Indeed, a spindle might be formed from a 5-inch or 6-inch carriage-bolt. At Woolwich Arsenal rockets are charged solid. The fuse is shaped into pellets, something like large peppermint lozenges, or cylindrical cakes of paste blacking, by hydraulic pressure in a mould. These pellets, discs, or cakes, which are almost as hard as a stone, are put into the case, and pressed in tight: the rocket is then fixed upright, and slowly drilled, as I have seen, with a conical borer, working vertically, to let the dust fall and clear itself. This mode must not be imitated by an amateur; indeed, without accurate machinery, the desired object could not be effected, and there is constant liability to danger.
The fuse of a rocket, when consolidated, assumes the form of fig. 18, with the head sawn off, except that the hollow is tapering, instead of cylindrical; and the rocket stands thus—
1⁄3cup + 6 choke & hollow + 11⁄3solid +1⁄3plaster = 8 diameters.
In the trade, meal powder, saltpetre, and charcoal, go by the names of meal, petre, and coal. Common coal, for burning in fires, is never employed in pyrotechny; it would produce only dull red sparks and smoke.
Meal, or petre, added to a fuse quickens it; sulphur slackens it. 6 meal, 1 sulphur, make a quickmatch that blows through a leader with great violence. 1 meal, 1 sulphur, will scarcely burn; pure meal only should be used for match, or grain powder with hot starch. It has already been stated that nitre in powder is sometimes adulterated with salt, and that it is impossible to make a rocket with such stuff. Powdered chlorate of potash is sometimes adulterated with nitre: with such mixture it is equally impossible to produce good colours: nitre whitens flame, and overpowers colour.
Chlorate of potash, charcoal, sulphur, stearine, used separately, with discretion, vivify colours; calomel deepens the colour, but slackens the flame.
Star compositions which inflame vigorously in dry summer weather, will often scarcely burn at all in damp weather; this is especiallythe case with stars containing nitrate of strontian.
In washing sulphur, stir it with a wooden spoon; if a silver one were used, a black sulphide would be formed on the surface, very difficult to remove. If silver coins in the pocket get tarnished while using sulphur, rub them with salt, or chalk, or whiting.
A magnet is convenient for lifting tacks, small screws, &c., from divisions in nail boxes.
If the brass tube formers get tarnished, scrape off the lacquer with a knife, sand paper them anew, and give them a fresh coat of lacquer.
Let all wheel frames and woodwork be coloured black, either with paint, or with a mixture of vegetable or lamp black and size, or thin glue, to prevent their being seen. A white thread hung upon a bush, is visible many yards off; a black one can scarcely be seen a few feet distant. Black is not only invisible, but it throws the brilliancy of sparks, and the vividness of colours, into stronger relief.
Let every article be dried, reduced to a finepowder, put into a clean bottle, and carefully corked: also let every bottle be labelled: the labels are best stuck on with paste, not gum: gum labels are apt to drop off in damp weather.
Let all metallic articles, liable to rust, be wiped with a rag dipped into olive oil, before being laid by for future use.
Before putting aside the six-inch circular frying-pan, set it over the fire till warm, put into it a lump of tallow, and smear it with a rag: when wanted for use, set it on the fire, put into it a cupful of water and a piece of soda; make the water boil, and stir it well round; pour away the water, and dry the pan over the fire.
Let muslin sieves always be dried before being put aside; also, again, before use. Zinc sieves may simply be wiped dry.
Have a place for everything; and keep everything in its place.
Faraday, the great master in experimental lectures, always devoted many hours to the preparation of his experiments for each lecture. No point, however trifling, bearing upon the success of the experiment, was consideredunimportant: he used to try the stoppers of all the bottles he had to use, to see that they had not become fixed, and thus would cause delay by requiring forcible opening. His example cannot be too carefully copied. Before firing a display, all posts, spindles, lines, staples, screws, touch-paper, portfires, pieces of leadered quickmatch, &c., should be carefully provided. A yard of tape slowmatch, hung to a nail at the top of a post, will supply fire for a long time.
A book should be kept for future guidance, in which should be written the quantity of composition required to make a certain number of articles of a certain size: by attending to this, much waste will be prevented.
Never, upon any account, leave compositions lying about; and let nothing be done by candlelight, except making cases. Quickmatch, especially, ought to be kept locked up, so that nobody can get to it.
Never put squibs, crackers, &c., into the pockets: a stray spark might ignite the whole, and cause most serious mischief.