Part 2

Put into a vial 1/2 an ounce of white wax, (bleached bees' wax), pour upon it 5 ounces of mineral naphtha, (coal or gas tar naphtha), keep it tightly corked.

TO MAKE STEARINE SOLUTION.

Dissolve a piece of composite candle in mineral naphtha, in the same way. Mineral naphtha must not be used near a candle or fire, as it gives off an inflammable vapour, at less than 100° Fahrenheit.

TO MAKE GUM SOLUTION.

There is no better way of preparing this than simply to put cold water upon gum arabic, and let it stand till dissolved. If for sticking purposes, as much water as will just cover the gum will be sufficient; but, for making quickmatch, 1 ounce or 1-1/4 ounce of gum to a pint of water. If required in a hurry, put the gum into _cold_ water, in a pipkin, or tin saucepan, set it on the fire, make it boil, and keep stirring till dissolved. When cold, bottle, and cork it.

TO MAKE DEXTRINE SOLUTION.

Take half an ounce of dextrine, and 5 ounces, or a quarter of a pint of cold water, put the dextrine into a cup or basin, add a little of the water, and mix it well with a teaspoon, rubbing it till all is dissolved; then add the remainder of the water, stir well together a second time, pour it into a vial, and cork for use. Dextrine, wetted to the consistency of honey, may be used instead of thick gum-arabic water, for pasting. For this purpose it is advisable to keep either in a wide-mouthed bottle, and to set the bottle in a gallipot containing a little water; the brush, a camel's-hair pencil, or very small sash-tool with 1/3 of the bristles cut away on each side, to render it flat, can then be kept in the water, when not in use; this will prevent it, on the one hand, from becoming dry and hard; and, on the other, from getting clogged and swollen. It can be squeezed between the thumb and fingers, when wanted for use. The flat gum brushes now sold, bound with tin, are not pleasant to use, as the tin oxidises, and turns of a disagreeable brown colour. If there is a difficulty in obtaining a graduated water measure, one sufficiently correct for pyrotechnic purposes may be made with a vial. Paste a narrow strip of paper up the outside of the vial, weigh 4 ounces of water in a cup, in the scales: pour it into the vial, mark the height, and divide it into 4 equal parts, for ounces; of course, it can be graduated into half and quarter ounces, and increased, if large enough, to 5 or more ounces. A gallon of distilled water weighs exactly 10 pounds. Consequently, a pint of pure water weighs a pound and a quarter. This is also near enough for spirit, though, of course, spirit is a trifle lighter. Doctors' vials are often marked with ounce divisions.

TO MAKE PASTE.

Paste is most economically made in a zinc pot, which may be 4 inches deep, and 3-1/2 inches diameter. Any zinc worker will make one to order for about 6_d._ Put into it 2 ounces of wheaten flour, add a little cold water, rub the two together with a spoon till smooth and free from lumps; pour in more water till the pot is full within about an inch; set the pot in half a saucepanful of water, put it on the fire; make the water boil, and keep it and the paste boiling for 4 or 5 minutes, stirring the paste the while. Remove it from the fire, and set it by to cool. The paste is to remain in the zinc pot, in which it will keep good for a length of time, and beautifully white.

Some recommend alum in paste, I think it best avoided, especially in cases intended to receive coloured fires. Alum is a double salt, a sulphate of alumina and potassa; it has an acid reaction; and, coming in contact with chlorate of potash and sulphur, may cause spontaneous combustion. A drop of sulphuric acid instantly ignites stars containing them. At theatres, the clown sometimes fires a cannon, with what appears to be a red hot poker; but which, in reality, is only a piece of wood, painted red. A mixture is made of chlorate of potash and sulphur, or sugar, a glass bead is filled with sulphuric acid, and the hole stopped up with wax. This is laid in the mixture, and when it is struck with the poker, the liquid escapes, and inflames the potash and sulphur. Sulphate of copper is a particularly dangerous salt, and must never be used, as it is almost certain to cause spontaneous combustion. Chertier, to whom pyrotechny otherwise owes so much, introduced an empirical preparation, by dissolving sulphate of copper in water, together with chlorate of potash, drying it, and wetting it with ammonia: but this, however dried, when again wetted, turns litmus paper red. Practicus has named it Chertier's copper. I discommend its use.

Two paste brushes will be sufficient for an amateur, sash-tools, one about an inch diameter, the other smaller for light purposes. Let them stand in the paste. If they get dry, the bristles fall out. For convenience, one may be kept in the paste, and one in water.

Dry clay, powdered and sifted as fine as possible, is used for plugging, or stopping up the bottoms of cases. I have, for some time, discontinued its use, and employ plaster of paris in preference. Directions will be given for each, so that the learner can adopt which he pleases: but plaster is infinitely preferable. It is an American improvement.

ROMAN CANDLE SCOOPS.

No species of fireworks require greater care in their construction than roman candles. In the first place the stars must be fierce, that they may light thoroughly: next, they must not be driven out with too great velocity. For this purpose the blowing-powder must be carefully adjusted. The stars, also, must be of so easy a fit that when put into the case they may fall to the proper depth of their own accord. If they require pushing, they are too tight, and will probably be blown out blind. When made as directed they will, necessarily, be of an easy fit, as they will be of the inner diameter of the brass tube, while the bore of the case is equal to its external diameter.

To regulate the blowing powder, prepare a number of little scoops, like fig. 5, which is about the right size for the bottom star. They are formed of pieces of tin, zinc, or copper. Cut a long strip of tin, 1/2 an inch broad; cut this across into 7 pieces, of the following lengths, 1-5/8, 1-6/8, 1-7/8, 2, 2-1/8, 2-3/8 and 4 inches. Round off the corners. Take a piece of brass wire, or stair-rod, about 1/4 inch diameter, and with the wooden mallet, before mentioned, fig. 26, bend each of the pieces round the rod into a half cylinder, or gutter. Take up the smallest, and hold 5/8 of an inch of the end of the stair-rod in the end of the semicylinder, to keep it open; put the other part from a to b, fig. 5, in a vice, and pinch it up; it will assume the form represented; the bowl part will be 5/8 long, and the handle 1 inch long. Make the bowl of the next scoop 6/8 of an inch long, the next 7/8, and so on; the handle will always be 1 inch long. The last, for the top star, will have a bowl of 3 inches. The smallest scoop ought to hold as much grain powder as will weigh about 1/12 of the star; but to have the scoops accurate, it will be necessary to charge a roman candle, fire it, and observe whether the stars go a uniform height. For measuring the interval fuse, or fuse between the top of one star and the bottom of the next, a large scoop of the size of fig. 10 will be required. The tin may be an inch broad, and the bowl part 2-1/2 inches long, bent round the rammer, fig. 4. To adjust it, take a roman candle case, fit it on the foot, fig. 9, which is a piece of wood, or brass, turned with a tenon to fit tight in the bottom of the case. Fill the scoop, and strike it level, with a straight-edge; empty it into the case, rest the foot on a flat surface; insert the rammer, fig. 4, and jolt it up and down, a dozen times, or more, lifting it about 1/2 an inch at a time; put in another scoopful, and jolt it in like manner. If the 2 scoopfuls, thus compressed, fill an inch of the case, the scoop will be correct. If more or less, the scoop must be shortened, or lengthened, accordingly.

A piece of writing-paper may be pasted and wound twice round the handle of each scoop, as from a to b, fig. 4. One dot can be put upon the scoop, for the first, or bottom, star; two dots, for the second scoop, &c., or any memorandum can be written upon them, for future guidance. Should they get soiled, they may be cleaned with a soaped damp piece of sponge.

Gunpowder, for fireworks, is used in two forms; meal-powder, and grain-powder. Meal-powder is a fine black dust, and is employed in all cases of mixing. Grain-powder is of three kinds, F, FF, and FFF, fine, double fine, and treble fine. FFF is best for crackers, simply because it runs rapidly down the pipes: for driving stars, shells, &c., F will be sufficient; but FFF may be employed: FF need not be purchased. All kinds of powder may be obtained of Pinnell, 214, Whitechapel Road. If, in any place, there should be a difficulty in obtaining meal-powder, F grain-powder may be crushed in a leather bag, by laying the bag on a hard surface, and beating it with a hammer. The leather should be of the same kind as shoes are made of.

TO CHARGE ROMAN CANDLE CASES.

Pour some F grain-powder into a wooden bowl, or platter, represented by fig. 11. Round the edge lay the little blowing-powder scoops, side by side, beginning with the smallest at a, the next at b, and so on to g. Put some roman candle fuse into a large tin scoop, made to stand on a flat bottom, like fig. 12, the same, in shape, as used by tea-dealers; and, on the right-hand of it, lay the charging-fuse scoop, fig. 10. If the roman candle is to contain different-coloured stars, set seven in a row, in the order desired. When the cases are intended to be fired in threes or fours, the stars in one may be all blue, in another crimson, in another green, in another white. Fit the foot, fig. 9, in the bottom of the case, put in a scoopful of clay, insert the rammer, fig. 4, and jolt it till the clay is well compressed. The clay should fill 1/2 an inch. This being done, invert it, and shake out any little dust that may remain. Put in the little scoopful a, of F grain-powder; then lay the scoop at A. Now put in a star. As previously stated it ought to fall of its own accord; but make sure that it has reached the blowing-powder, by putting in the rammer. Having ascertained this, put in a scoop of fuse, fig. 10; lay the scoop on the left of fig. 12; insert the rammer and jolt it; put in another scoop of fuse, fig. 10; lay the scoop on the right of fig. 12; insert the rammer and jolt it, as before. Then proceed with the scoop b of grain-powder, and lay it at B, and so on, till the case is filled. The fuse on the top star is best driven in with a short solid rammer and mallet, as it is difficult to jolt the long rammer in so small a space. The last 1/8 of an inch, near the mouth of the case, should be fine meal-powder, as it binds better than the roman-candle fuse, and also blows off the leader pipe.

The blowing-powder scoops, having been laid at A, B, &c., all that is required is to turn the bowl or platter, a little round to the left, and they will come in rotation, ready for the next case. Also, by putting the scoop, fig. 10, alternately to the left and right of the scoop, fig. 12, it will always be known whether the proper quantity of fuse has been put in.

Coloured stars, from their fierceness, have a tendency to burn in the cases. This defect may be remedied by putting upon each star a small scoopful of Starting Fire, No. 1, before putting in the interval fuse; as much as will fill round the sides of the star. This composition is somewhat fiercer than would suit for the regular fuse, so catches the blowing-powder sooner.

A roman candle is well charged when the stars isochronise, or come out at equal intervals of time: they should, also, theoretically, ascend to equal heights; but, with coloured stars, this cannot be perfectly insured, as some shrink more than others in drying, and, of course, fit more loosely; some are heavier, some fiercer than others.

The interval fuse must always be driven in at twice, never at once. Each star, with its blowing-powder and fuse, occupies about an inch and a half; perhaps a trifle more.

Instead of driving in clay at the bottom, plaster of paris may be used, and then the foot, fig. 9, will not be required. Have some plaster of paris in a wide-mouthed bottle; a glass of cold water with a salt-spoon in it; and a number of pieces of paper, about 4 inches square. Put a small quantity of the plaster on one of the pieces of paper; indent the middle with the finger; put to it a little water, and work it up with a dessert-knife. Just as it gets to the consistency of mortar, and is about to set, mould it with the fingers, to the shape of a cork; push it into the end of the case; rest the case on a flat surface; insert the rammer, and give it two or three slight jolts; turn it round a few times, and withdraw it. If the plaster sticks to the end of the rammer, it shows, either that you have used the plaster too wet, or have not turned the rammer round a sufficient number of times.

No more plaster must be mixed at a time than will suffice for one case. When plaster has once set, it cannot be mixed up a second time; therefore take a fresh piece of paper, and let the knife be cleaned every time. It is advisable to have two dessert-knives, then one can be used with which to scrape the other. As much plaster should be used as will fill the case up about 1/2 an inch. They must be set by to dry; their not requiring the use of the foot will be found a great convenience.

Roman candles are usually made from 3/8 to 6/8; but 5/8 is a very satisfactory size. If a roman candle is intended to be fired singly, twist a piece of touchpaper round the mouth. If the cases are intended to be fired in threes, fours, &c., to form a bouquet, or to be placed round a mine, jack-in-the-box, or devil-among-the-tailors, omit the touchpaper, and envelope the case in double crown, made to project an inch beyond the mouth, to receive the leader, or quickmatch.

A steel-pen inserted, nib backwards, in the end of a small paper tube, rolled round the end of a penholder, makes a neat little scoop. It may be fastened in with a little plaster of paris. A scoop may also be made with a quill.

Cracks in wooden bowls may be stopped with the same material; and, if painted over with linseed oil, after getting dry, will remain waterproof for a long time. A screw may be made to hold in brickwork, by drilling a hole in the brick, and pushing in the screw, covered with plaster.

TO MAKE TOUCHPAPER.

Dissolve 1/2 an ounce of nitre in 1/2 a pint of hot water. Procure some 12 lb. double crown blue; cut each sheet into four equal parts, 15 by 10. Lay them smooth upon each other, and, with a sash-tool dipped into the nitre solution, wash them over on one side, and hang them up to dry.

TO MAKE SLOWMATCH.

Dissolve 1 dram of nitrate of lead in 1/2 an ounce of boiling water. Cut a sheet of blotting paper into six equal parts, and wet them on both sides, with a sash-tool, with the solution. When dry, paste a piece all over, and upon it smoothly press another piece; upon this, pasted, put a third piece; and so on, till all the six form a stiff board. Lay them under a heavy weight; and, when dry, with a sharp knife and straight-edge, cut the whole into strips 1/4 of an inch broad. Four inches will burn about a quarter of an hour. Narrow tape, boiled in the solution, makes excellent slowmatch.

TO MAKE QUICKMATCH.

Put into a pan 1 lb. of grain-powder, or meal-powder; pour upon it some thin hot starch, and stir it well about, breaking all lumps, till the mixture is of the consistency of paint. Procure some lamp-cotton, such as forms the wicks of candles. It will probably consist of sixteen or twenty-four strands. Divide it carefully into lengths of eight strands. This is not so easy a task as might appear. The best way is to act the reverse of a man spinning string. Divide the end of the cotton, say of sixteen strands, into two of eight each; fasten them to two screw-hooks, a few inches apart. Take one in each hand, and walk backwards, gently pulling them apart, and when they catch, untwist them: with care they will separate without breaking or entangling. Drop the end of one of the pieces into the pan; and, as it keeps falling, coil it round and round in the mixture, and press it down with an iron spoon, until as much is pressed in as the quantity can saturate. Be very particular that it is thoroughly soaked. Have ready a wooden frame, fig. 13, of deal, resembling a swing looking-glass, with the glass taken out. It may be 5 feet by 4. The frame is to be supported on pivots between two uprights. Fix a nail or hook at the left-hand corner of the frame, and tie the end of the cotton to it which has been hanging outside the pan. Get a person to slowly turn the frame and hold it steady. Take hold of the cotton in the right hand, shut the hand, and allow the cotton to slip gradually and slowly through it, as the frame is turned; squeeze it very gently, so as to allow it to come out well coated, and contrive to make it as round as possible. When all the cotton is wound upon the frame, spread some sheets of paper--old newspapers--on the floor; at each corner place a brick; lay the four corners of the frame upon the four bricks; sift dry meal-powder all over the match, turn it over and sift over the other side. Prop the frame against the wall, and leave it to dry. One ounce of white starch will be sufficient for a pint and a half of water. Rub the starch up smooth with a little of the water, then add the rest, and boil it.

A NEW METHOD.

Put into a gallipot, or basin, some hot starch, made as before directed, or some cold gum-water, or cold dextrine solution; and with a small stencil-brush, or a 3/8 sash-tool, cut across the middle to make the bristles short and stubby, stir in some meal-powder, till it is well mixed and looks like black paint. To avoid repetition, it will be convenient to refer to this under the name of Meal-paste. Take two towel-horses, fig. 14, and set them parallel 5, 10, or 20 feet apart. In the top rail of each, drive four nails 1/2 an inch asunder. Fix the dry cotton to the nail a, carry it across to the opposite nail b, pass it round the second nail c, bring it to the opposite second nail, and so on, till the cotton lies in four parallel lines, like the strings of a harp placed horizontally. Hitch the cotton, without cutting it, to the hook of the weight, fig. 15. This weight is made by taking a piece of brass tube, 1 inch diameter, and 4 inches long. Stop one end with a bung, fill it with melted lead; and before it sets push in a lucifer match, having previously cut off the priming. As soon as the lead is cold, pull out the match, which having been partially burnt smaller, will come out easily, and in the hole left by it screw a cup-hook, as drawn. Invert the weight, pick out the bung, and fill its place with more melted lead. Now procure two pieces of planed deal board; one 4 inches square, the other 6 inches square. With the left hand hold the smaller piece close underneath the cotton; and with the sash-tool or stencil-brush, work the meal-paste _well into the fibres of the threads_, pressing the cotton on the board till it is thoroughly soaked, and rolling it over, laterally, to make it as round and smooth as possible. It is best to begin on the left, and work towards the right. If the wetting slackens the threads, pull them tight. Now brush some meal-powder through a fine sieve, to free it from lumps; put a tablespoonful or two upon the larger board; hold it close under the four threads, as the other, with the left hand, and move it laterally forwards and backwards, and down the whole length, at the same time brushing the meal over the threads, with a soft, dry, sash-tool, till they are smothered, and giving them an occasional jar to shake off the superfluous meal. By a little practice they may be made as smooth and as round as a piece of wire. Leave the weight hanging to them till they are dry. Instead of four nails on each rail, a dozen may be put; and if the towel-horses are set 12 yards apart, 144 yards may be soon made. In this case, three or four heavier weights would be required. These contrivances, however, are by no means necessary for an amateur; four hooks or nails opposite four others, anyhow supported, will be sufficient; and six or eight feet apart is a good distance. A small quantity may thus be made one day, and a small quantity another; and for this purpose it is best to use gum-water, as it is always ready, and a little can be added to the dry left the day before, and a little fresh meal stirred in. Three or four threads of white darning-cotton, which is of two twists, make very good match; knitting or crochet cotton, which is of three twists, produces, alone, excellent match; two or three pieces of the first, or two of the latter, put into a leader pipe, side by side, blow through with a violent report. Match may also be made of the very narrowest white tape, 3/16 of an inch broad; this, from its flatness, is peculiarly suited for enveloped stars. For general purposes, however, lamp cotton is decidedly the best, as it is most loosely twisted, and therefore the most absorbent. If match is liable to be exposed to damp, it should be cased in thick leaders, and be prepared with starch; in other respects, nothing can surpass gum-water. Of course iron pound-weights, with a ring in them, will answer the purpose, or an iron pestle tied to the cotton, or anything heavy; but the kind I have advised are most convenient. They will weigh about a pound and a quarter each. The weight may hang over a chair-back.

Match, to be perfect, ought, when cut across, to look black throughout; it should, also, be stiff, straight, and round; but, to test it, cut off about 10 inches; put one end of this into a leader pipe, so that 5 inches will be in the pipe, and 5 out. Hold the end of the leader with a pair of tongs, or lay it on the ground; light the naked end. If the match is good it will burn gradually, though swiftly, till it gets to the pipe; it will then blow through with a bang. The nearer the leader pipe fits the match the better, only it ought to be large enough to allow it to go easily in, without force: if laid in a roman candle case it would hardly puff: the smaller and smaller the tube becomes the louder and louder the report: the increase of power being in the inverse ratio of the diminution of space. A train of gunpowder laid in the open air, or confined in a tube, comports itself in the same way, as is well known. Match, when dry, should be kept straight; for, if it gets broken, it acts like a cracker, snapping at every break.

A piece of zinc rainwater pipe, of suitable length, furnished with a bottom and lid, or a couple of bungs, is convenient for keeping it in; but a far better contrivance is a deal box, 5 feet long, 3 inches deep, and 3 broad, made of 1/2-inch pine. The lid of this box can be readily furnished with three or five hinges, like a piano, only made with string instead of brass. Take two pieces of string, fig. 57, and tie them in a knot near the end, as at k. At x, fig. 58, make a bradawl hole through the back of the box, near the top, and push the strings through it; make another hole through the lid, put the string through it, and tie in a knot on the top, as at z: and so with the other four. This will render the explanation easier to understand; but, practically, a single piece of thicker string is best, if you can manage to tie the second knot in the exact spot you wish. The knots must not be too close to each other, as the lid requires a little play. For safety, the box ought to be furnished with a lock.

_ROCKETS._