driving in the end of the eighth case two or three ladlesful of slow fire, to burn till the wheel has stopped 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 you may put a small gerbe; and let the cases on the spokes be short, and filled with a strong brilliant charge.

Illuminated Spiral Wheel.-First have a circular horizontal wheel made two feet diameter, with a hole quite through the nave; then take three thin pieces of deal, three feet long each, and three-fourths of an inch broad each nail one end of each of these pieces 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. The wheel being thus made, have a loop planed down very thin and flat; then nail one end of it into the fell of the wheel, and wind it round the 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 you may place any number of cases, which must incline downwards, and burn two at a time. If the wheel should consist of ten cases, you 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.

Double Spiral Wheels.-For these wheels, the block or nave must be as long as the height of the worms, or spiral lines, but must be made very thin, and as light as possible. In this block must be fixed 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: close these worms with illuminations, the same as those on the single wheels; but the horizontal wheel you may clothe as you like. At the top of the worm place a case of spur-fire, or an amber light.

Balloon Wheels. They are made to turn horizontally: they must be made two feet diameter, without any spokes, and very strong, with any number of sides. On the top.

of a wheel range and fix in pots, three inches diameter and seven inches high each, as many of these as there are cases on the wheel: near the bottom of each pot make a small vent; into each of these vents carry a leader from the tail of each case; load some of the pots with stars, and some with serpents, crackers, &c. As the wheels turn, the pots will successively be fired, and throw into the air a great variety of fires.

BALLOON CASES.

You must have an oval former, turned of smooth wood; then paste a quantity of brown or cartridge-paper, and let it lie till the paste has soaked all through; this done, rub the former with soap or grease, to prevent the paper from sticking to it; then lay the paper on in small slips, till you have made it one third of the thickness of the shell intended. Having thus done, set it to dry; and when dry, cut it round the middle, leaving about one inch not cut, which will make the halves join much better than if quite separated. When you have some ready to join, place the halves even together, and let that dry; then lay on paper all over as before, every where equal. When the shell is thoroughly dry, burn a vent at top with a square iron.

Shells that are designed for stars only, may be made quite round, and the thinner they are at the opening the better; for if they are too strong, the stars are apt to break at the bursting of the shell. Balloons must always be made to go easy into the mortars.

MORTARS.

These mortars must be made of pasteboard, with a small copper chamber at bottom, in which the powder is to be placed, on which the balloon is to be put. In the centre of the bottom of this chamber make a small hole a little down the foot; the hole must be met by another of the same size as the foot. Then putting a quick-match, or touch-string, of touch-paper into the hole, your mortar will be ready to be fired.

To load Air Balloons with Stars, Serpents, &c. &c.— When you fill your shells, you must first put in the serpents,

rains, &c. or whatever they are composed of, then the blowing powder; but the shells must not be quite filled. All those things must be put in at the fuse-hole, but marrons being too large to go in at the fuse-hole, must be put in before the inside shall be joined. When the shells are loaded, glue and drive in the fuses very tight. The number and quantities of each article for the different shells are as follows:

1 oz. driven or rolled stars, or as many as will fill the shell.

MORTARS to throw aigrettes are generally made of pasteboard, of the same thickness as balloon mortars, and two diameters and a half long in the inside from the top of the foot the foot must be made of elm without a chamber, but flat at top, and in the same proportions as those for balloon mortars; these mortars must also be bound round with a cord: sometimes eight or nine of these mortars, of about three or four inches diameter, are bound all together, so as to appear but one; but when they are made for this purpose, the bottom of the foot must be of the same diameter as the mortars, and only half a diameter high. The mortars being bound well together, fix them on a heavy solid block of wood. To load these mortars, first put on the inside bottom of each a piece of paper, and on it spread one ounce and a half of meal and corn-powder mixed; then tie the serpents up in parcels with quickmatch, and put them in the mortar with their mouths downwards; but take care the parcels do not fit too tight in the mortars, and that all the serpents have been well primed with powder wetted with spirit of wine. On the

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top of the serpents in each mortar lay some paper or tow; then carry a leader from one mortar to the other all round, and then from all the outside mortars into that in the middle these leaders must be put between the cases and the sides of the mortar, down to the powder at bottom: in the centre of the middle mortar fix a fire-pump, or brilliant fountain, which must be open at bottom, and long enough to project out of the mouth of the mortar; then paste papers on the tops of all the mortars.

Mortars thus prepared are called a nest of serpents. When these mortars are to be fired, light the fire-pump, which when consumed will communicate to all the mortars at once by means of the leaders. For mortars of 8, 9, orl, 10 inches diameter, the serpents should be made in one' and two-ounce cases, six or seven inches long, and fired by a leader brought out of the mouth of the mortar, and turned down on the outside, and the end of it covered with paper, to prevent the sparks of the other works from setting it on fire. For a six-inch mortar, let the quantity of powder for firing be two ounces; for an eight-inch, two ounces and three quarters; and for a ten-inch, three ounces and three quarters. Care must be taken in these, as well as small mortars, not to put in the serpents too tight, for fear of bursting the mortars. These mortars may be loaded with stars, crackers, &c.

If the mortars, when loaded, are sent to any distance, or liable to be much moved, the firing powder should be secured from getting amongst the serpents, which would endanger the mortars, as well as hurt their performance. To prevent this, load the mortars thus: First put in the firing powder, and spread it equally about; then cut a round piece of blue touch-paper, equal to the exterior diameter of the mortar, and draw on it a circle equal to the interior diameter of the mortar, and notch it all round as far as that circle: then paste that part which is notched, and put it down the mortar close to the powder, and stick the pasted edge to the mortar: this will keep the powder always smooth at bottom, so that it may be moved or carried anywhere without receiving damage. The large single mortars are called pots des aigrettes.

The

spindle put a nut, to keep the wheel from falling off. 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, you must have a post, on which you intend to fire the work, with an iron screw in the top of it, to fit one of the holes in the ball on the screw fix the ball; then in the top hole of the ball put a little meal-powder and some loose quickmatch then 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, and the work will be ready to be fired. By the leader the powder and match in the centre is fired, which will light the match at the ends of the spokes all at once, whereby all the wheels will be lighted at once. There may

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be an addition to this piece, by fixing a small globe on each wheel, or one on the top wheel only. A grey charge will be proper for the wheel-cases..

Stars with Points.

THESE stars are made of different sizes, according to the work for which they are intended; they are made with cases from one ounce to one pound, but in general with four-ounce cases, four or five inches long: the case must be rolled with paste, and twice as thick as that of a rocket of the same bore. Having rolled a case, pinch one end of it quite close; then drive in half a diameter of clay; and when the case is dry, fill it with composition two or three inches to the length of the cases with which it is to burn: at top of the charge drive some clay; as the ends of these cases are seldom pinched, they would be liable to take fire. Having filled a case, divide the circumference of it 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 the other carry a quick-match, and secure it with paper: this paper must be put on in the manner of that on the end of wheel-cases, so that the hollow part,