Varieties put in first be about a quarter less than the bore of the

of Con

case; but let the next star be a little larger, and the struction. third star a little larger than the second, and so on: let them increase in diameter till within two of the top of the case, which two must fit in tight. As the loading of fire-pumps is rather difficult, it will be necessary to make two or three trials before depending on their performance when you fill a number of pumps, take care not to put in each an equal quantity of charge between the stars, so that when they are fired, they may not throw up too many stars together. Cases for fire-pumps should be made very strong, and rolled on four or eight ounce formers, 10 or 12 inches long each.

125 Vertical scroll

wheel.

Fig. 57.

126 Fire-globe.

127 Method of

works to be

A vertical scroll wheel may be made of any diameter, but must be constructed as in fig. 57. to do which proceed thus: Have a block made of a moderate size, in which fix four flat spokes, and on them fix a flat circular fell of wood; round the front of this fell place portfires; then on the front of the spokes form a scroll, either with a hoop or strong iron wire; on this scroll tie cases of brilliant fire, in proportion to the wheel, head to tail, as in the figure. When you fire this wheel, light the first case near the fell; then, as the cases fire successively, the circle of fire will gradually diminish; but whether the illuminations on the fell begin with the scroll or not, is immaterial.

N. B. This wheel may be put in the front of a regulated piece, or fired by itself, occasionally.

There are two sorts of fire-globes; one with projected cases; the other with the cases concealed. For the latter have a globe made of wood, of any diameter, and divide the surface of it into 14 equal parts, and at each division bore a hole perpendicular to the centre: these holes must be in proportion to the cases intended to be used: 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 the other, for leaders which must be carried from case to case, so that they may all be fired together; this done, cover the globe with a single paper, and paint it. These globes may be used to ornament a building.

Fire-globes with projected cases are made thus: the globe being made with 14 holes bored in it as usual, 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, so that they may all take fire at the same time. Fire-globes are supported by a pintle, made to fit the hole in which there is no case.

Nothing adds more to the appearance of fire-works placin, fire than placing them properly; though this chiefly depends exhibited. on the judgment of the maker. The following are the rules generally observed, whether the works are to be fired on a building or on stands: if they are a double set, place one wheel of a sort on each side of the building; and next to each of them, towards the centre, place a fixed piece, then wheels, and so on; leaving a sufficient distance between them for the fire to play from one without burning the other. Having fixed some of the works thus in front, place the rest behind them, in the centre of their intervals: The largest piece, which is generally a regulated or transparent piece, must be placed in the centre of the building, and behind it a sun, which must always stand above all the other works. A Hittle before the building, or stands,, place the large

gerbes; and at the back of the works six marroon bat- Varieties teries, pots des aigrettes, pots des brins, pots des sau- of Coucissons, air-balloons, and flights of rockets: the rocket struction. stands may be fixed behind, or anywhere else, so as not to be in the way of the works.

Single collections are fired on stands; which are made in the same manner as theodolite stands, only the top part must be long or short occasionally: these stands may be fixed up very soon without much trouble. The following order of Firing will serve as a specimen of the Plan to be pursued in an exhibition of Fire

2. Golden glory

3. Octagon vertical wheel
4. Porcupine's quills
5. Cross fires

6. Star-piece with brilliant 7. Six vertical wheels 35. Brilliant sun

36. Large flight of rockets.

rays

When water-works are to be exhibited, divide them into several sets, and fire one set after every fifth or sixth change of land and air-works. Observe this rule in firing a double set of works: Always begin with skyrockets, then two moveable pieces, then two fixed pieces, and so on; ending with a large flight of rockets, or a marroon battery: if a single collection, fire a fixed piece after every wheel or two, and now and then some air and water-works.

Varieties of Con

128

:

Fig. 58. represents a fountain of 30 rockets. Let A be a perpendicular post, 16 feet high from the ground, truction. and 4 inches square. Let the rail, or cross piece C, be one foot six inches long, three inches broad, and one tain of thick. The rail D, at bottom, must be six feet long, y-rockets. one foot broad, and one inch thick. F and Gare the g. 53. two sides which serve to supply the rails D, E, H, I, C: these sides are one foot broad at bottom, and cut in the front with a regular slope, to three inches at top; but their back edges must be parallel with the front of the pots A. The breadth of the rails E, H, I, will be determined by the breadth of the sides all the rails must be fixed at two feet distance from each other, and at right angles with the pots, Having placed the rails thus, bore in the bottom rail Ic holes, at equal distances, large enough to receive the stick of a one pound rocket in the back edge of this rail cut a groove from one end to the other, fit to contain a quick-match; then cut a groove in the top of the rail, from the edge of each hole, into the groove in the back in the same manner cut in the second rail, E, eight holes and grooves; in the third rail, H, six holes and grooves; in the fourth rail, I, four holes and grooves; and in the top rail, two holes and grooves. B, a rail with holes in it to guide the ends of the rocket sticks; this rail must be fixed six feet from the rail D. The fountain frame being thus made, prepare the rockets thus: Tie round the mouth of each a piece of thin paper, large enough to go twice round, and to project about an inch and a half from the mouth of the rocket, which must be rubbed with wet mealpowder; in the mouth of each rocket put a leader, which secure well with the paper that projects from the mouth of the case: these leaders must be carried into the grooves in the back of the rails, in which lay a quick-match from one end to the other, and cover it with pasted paper holes must be made in the rail D, to receive the ends of the sticks of the rockets in the rail E, and so on to the fourth rail; so that the sticks of the rockets at top may go through all the rails. The rockets being so prepared, fix a gerbe, or white flower-pot, on each rail, before the post, with its mouth inclining a little forwards: these gerbes must be lighted all at once. Behind or before each gerbe, fix a case of brilliant or slow fire: these cases must be filled so that they may burn out one after the other, to regulate the fountain; which may be done by carrying a leader from the end of each slow or brilliant fire, into the groove in the back of each rail. Different fixed rockets may be used in these fountains: but it will be best to fill the heads of the rockets on each rail with different sorts of things, in this manner; those at top with crackers, the next with rains, the third with serpents, the fourth with tailed stars, and the last flight with common or brilliant stars.

[29

a tree.

59.

The piece called a palm tree, though made of common fires, and of a simple construction, has a very pleasing effect; from the fires intersecting so often, that they resemble the branches of trees. Let A (fig. 59.) be a perpendicular post, of any thickness, so that it be sufficiently strong to hold the cases; let the distance from B to C be two feet six inches, and from C to D two feet six inches, and let the length of each crovspiece be two fee; on each end of each fix a five-pointed star: then fix, on pegs made for the purpose, twelve inch balf-pound cases of brilliant fire, as in the figure.

All the cases and stars must be fired at once. piece should be fixed high from the ground.

This Varieties

of Construction.

130

Plate CCCCLVI.

An illuminated pyramid, with Archimedian screws, a globe, and vertical sun, may be of any size. One made according to the dimensions of fig. 60. will be of a good Illuminated proportion, whose height is 21 feet; from C to D, six pyramid. feet; from E to F, nine feet: the space between the Fig. 60. rails must be six inches, and the rails as thin as possible : in all the rails stick portfires at four inches distance. The Archimedian screws, G, K, are nothing more than double spiral wheels, with the cases placed on their wheels horizontally instead of obliquely. The vertical sun, I, need not consist of more than 12 rays, to form a single glory. The globe at top must be made in pro-portion to the pyramid; which being prepared according to the preceding directions, place the leaders so that all the illuminating portfires, screws, globe, and sun, may take fire together. The pyramid must be support-ed by the two sides, and by a support brought from a pole, which must be placed two feet from the back of the pyramid, that the wheels may run freely.

131

A rose-piece may be used for a mutation of a regu- Rose piece lated piece, or fired by itself: it makes the best appear- and sun. ance when made large; if its exterior diameter be six Fig. 61.. feet, it will be of a good size. Fig. 61. shows the manner in which it appears before it is fired. Let the outer 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 outer fell place as many half-pound cases of brilliant charge as you think proper, but the more the better; for the nearer the cases are placed, the stronger will be the rays; the illuminations should be placed within three inches of each other: they must all be fired toge-ther, 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.

132

Fig. 62.

Fig. 62. represents an illuminated star. Let the dia- Transpa meter from A to B be two feet, and from C to D seven rent stars with illumi feet. First make a strong circular back or body of the nated rays.. star, two feet diameter, to which fix the illuminated rays: in the centre of the front of the body fix a spindle, on which put a double triangular wheel, six inches diameter, clothed with two ounce cases of brilliant charge: the cases on this wheel must burn but one at a time. Round the edge of the body, nail a hoop made of thin wood or tin: this hoop 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 and garter may be cut out of strong pasteboard or tin, made in this manner: Cut a round piece of pasteboard or tin, two feet diameter, on which draw a star, and cut it out; then over the vacancy paste Persian silk; paint the letters yellow; four of the rays yellow, and four red; the cross in the middle may be painted half red and half yellow, or yellow and blue. This transparent star must be fastened to the wooden hoop by a screw, made so as to take off and on; the illuminated rays are made of thin wood, with tiu sockets fixed on their sides within four inches of each other; in these sockets stick illuminating portfires: behind the point of each ray fix a half pound case of gray, black, or Chinese fire.

N. B. The illuminated rays are to be lighted at the

same

Varieties same time as the triangular wheel, or after it is burnt of Con- out; which may be done by a tin barrel being fixed to struction. the wheel, after the manner of those in the regulated pieces. Into this barrel carry a leader from the illuminated rays, through the back of the star; and this leader must be met by another, brought from the tail of the last case on the wheel.

nated table

star.

Fig. 63.

133 Transpa- Fig. 63. represents a table star, whose diameter from rent illumi- E to F, is 12 feet; and from E to I, four feet. This proportion, observed on each side, will make the centre frame four feet square in this square fix a transparent star, as in the figure. This star may be painted blue, and its rays made as those of the flaming stars described before. The wheel for this star may be composed of different coloured fires, with a charge or two of slow fire; the wheels a, a, a, a, may be clothed with any number of cases, so that the star-wheel consist of the same: the illuminating portfires, which must be placed very near each other on the frames, must be so managed as to burn as long as the wheels, and lighted at the same time.

134 Regulated The regulated illuminated spiral piece, with a projected illuminated star-wheel illuminated, is represented by fig. 64. and is spiral piece. thus made. Have a block made eight inches diameter; Fig. 64.

135 Illuminated

in this block screw six iron spokes, which must serve for spindles for the spiral wheels: these wheels are made as usual, each one foot and a half diameter, and three feet in height the spindles must be long enough to keep the wheels four or five inches from one another at the end of each spindle must be a screw-nut, on which the wheels that hang downwards will run; and on the spindles which stand upwards must be a shoulder, for the blocks of the wheels to run on.

The projected star-wheel must turn on the same spindle on which the large block is fixed; this spindle must be long enough to allow the star-wheel to project a little before the spiral wheels: the exterior diameter of the star-wheel must be three feet five inches. On this wheel fix three circles of iron wire, and on them portfires; on the block place a transparent star, or a large five-pointed brilliant star. The cases on this wheel may burn four at once, as it will contain nearly twice the number of one of the spiral wheels: the cases on the spiral wheels must be placed parallel to their fells, and burn two at a time.

A figure piece illuminated with five-pointed stars. figure piece. The construction of this piece is very easy, as shown by Fig. 65. fig. 65. whose diameter from B to Ĉ is eight feet, and from D to F two feet: the vertical wheel in the centre must be one foot diameter, and consist of six four-ounce cases of different coloured charge, which cases must burn double on the frames fix five-pointed brilliant or blue stars, rammed four inches with composition: let the space between each star be eight inches; at each point fix a gerbe, or case of Chinese fire. When to be fired, let the gerbe, stars, and wheel, be lighted at the same time.

136 Illuminated The star-wheel illuminated, is shown by fig. 66. Its star-wheel. exterior fell is made of wood, three feet six inches or Fig. 66. four feet diameter; within this fell, form with iron wire three circles, one less than the other, so that the diameter of the least may be about 10 inches: place the portfires on these fells with their mouths inclining outwards, and the portfires on the points of the star with their mouths projecting in front; let the exterior

I

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 posts, 1; the bottom rail must be six feet long: all the mortars must incline a little forwards, that they may be easily discharged; and the spur-fires rammed exactly alike, that the mortars may all be fired at the same time. Having prepared the pyramid according to the preceding directions, carry pipes of communication from one spur-fire to the other.

:

Fig. 68. represents one half of the illuminated regu-Illuminated lating piece.-A, A, A, A, are flat wooden spokes, each regulating five feet long at the end of each place a vertical wheel, piece. Fig 68. 10 inches diameter, clothed with six four-ounce cases of Plate brilliant fire these cases must burn but one at a time: CCCCLVII. on two of the spokes of each wheel place two portfires, which must be lighted with the first case of the wheel: on each spoke A, A, &c. 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 all one way, and be made to take fire successively one after the other, so that they may assist the whole piece to turn round.

The diameter of the large wheel must be two feet and a half; and its fell made of wood, which must be fixed to the large spokes: on this wheel place 24 cases of the same sort with those on the small wheels; these cases must burn four at a time in this wheel make three circles with iron wire, and on them place illuminating portfires, as in the figure: the star-points on the large spokes may be made of thin ash-hoops; the diameter of these points close to the centre-wheel must be 11 inches on these points place portfires, at three inches and a half distance one from the other.

Fig. 69. represents the blocks of this piece. The dia- Fig. 6 meters of these blocks, at A and B, must be eight inches; and C and D, four inches and a half: the length of each of those blocks must be six inches: at the small ends of these blocks fix an iron wheel, five inches diameter, and these wheels must have teeth, to turn the wheel F.: this wheel is fixed on a small spindle screwed into the large spindle, which goes through the two blocks, and on which they run.

Supposing fig. 68. to be on the block A, in fig. 69. and to turn to the right, and another piece of the same construction on the block B, with its fires placed so as to turn it to the left; you will find them move very true and fast, by the help of the three iron wheels, which serve to regulate their motions, as well as to assist them in turning let the iron circles in the front of the great wheels be of different diameters, so that when fired there may appear six circles. When this piece is fired all the wheels and illuminations must be lighted at one time.

Aquatic

Aquatic Fireworks.

139

140 Water-rockets.

142 Horizontal waterwheels.

Aquatic Fireworks.

Works that sport in the water are much esteemed by most admirers of fire-works, particularly water-rockets; and as they seem of a very extraordinary nature to those who are unacquainted with this art, they merit a particular explanation.

Water-rockets, may be made from four ounces to two pounds. If larger, they are too heavy; so that it will be difficult to make them keep above water without a cork float, which must be tied to the neck of the case; but the rockets will not dive so well with as without floats.

pro

Cases for these are made in the same manner and portion as sky-rockets, only a little thicker of paper. When you fill those which are driven solid, put in first one ladleful of slow fire, then two of the proper charge, and on that one or two ladles of sinking charge, then the proper charge, then the sinking charge again, and so on, till you have filled the case within three diameters; then drive on the composition one ladleful of clay; through which make a small hole to the charge; then fill the case, within balf a diameter, with corn-powder, on which turn down two or three rounds of the case in the inside; then pinch and tie the end very tight; having filled the rockets (according to the above directions), dip their ends in melted rosin or sealing-wax, or else secure them well with grease. When you fire those rockets, throw in six or eight at a time; but, if you would have them all sink, or swim, at the same time, you must fill them with an equal quantity of composition, and fire them altogether.

Pipes of communication, which may be used under water, must be a little thicker in the paper than those for land. Having rolled a sufficient number of pipes, and kept them till dry, wash them over with drying oil, and set them to dry; but when you oil them, leave about an inch and a half at each end dry, for joints; as if they were oiled all over, when you come to join them, the paste would not stick where the paper is greasy; after the leaders are joined, and the paste dry, oil the joints. These pipes will lie many hours under water, without receiving any damage.

To make horizontal wheels for the water, first get a large wooden bowl without a handle; then have an eight-sided wheel made of a flat board 18 inches diameter, so that the length of each side may be near seven inches: in all the sides cut a groove for the cases to lie in. This wheel being made, nail it on the top of the bowl; then take four eight-ounce cases, filled with a proper charge, each about six inches in length. Now, to clothe the wheel with these cases, get some whitishbrown paper, and cut it into slips four or five inches broad and seven or eight long: these slips being pasted all over on one side, take one of the cases, and roll one of the slips of paper about an inch and a half on its end, so that there will remain about two inches and a half of the paper hollow from the end of the case: tie this case on one of the sides of the wheel, near the corners of which must be holes bored, through which put the packthread to tie the cases: having tied on the first case at the neck and end, put a little meal powder in the hollow paper; then paste a slip of paper on the end of another case, the head of which put into the hollow paper on the first, allowing a sufficient distance from the tail

of one to the head of the other for the pasted paper to Aquatic bend without tearing: tie on the second case as you did Fireworks. the first: and so on with the rest, except the last, which must be closed at the end, unless it is to communicate to any thing on the top of the wheel, such as fire-pumps or brilliant fires, fixed in holes cut in the wheel, and fired by the last or second case, as the fancy directs: six, eight, or any number, may be placed on the top of the wheel, provided they be not too heavy for the bowl.

Before tying on the cases, cut the upper part of all their ends, except the last, a little shelving, that the fire from one may play over the other, without being obstructed by the case. Wheel cases have no clay drove in their ends, no pinched, but are always left open, only the last, or those which are not to lead fire, which must be well secured.

143

mines.

For water mines you must have a bowl with a wheel Water on it, made in the same manner as the water-wheel; only in its middle there must be a hole, of the same diameter as that of the intended mine. These mines are tin pots, with strong bottoms, and a little more than two diameters in length: the mine must be fixed in the hole in the wheel, with its bottom resting on the bowl; then loaded with serpents, crackers, stars, small waterrockets, &c. in the same manner as pots of aigrettes; but in their centre fix a case of Chinese fire, or a small gerbe, which must be lighted at the beginning of the last case on the wheel. These wheels are to be clothed as usual.

144

Bowls for water-globes must be very large, and the Fire-globes wheels on them of ten sides; on each side nail a piece for the waof wood four inches long; and on the outside of each ter piece cut a groove, wide enough to receive about onefourth of the thickness of a four-ounce case: these pieces of wood must be nailed in the middle of each face of the wheel, and fixed in an oblique direction, so that the fire from the cases may incline upwards: the wheel be-ing thus prepared, tie in each groove a four-ounce case filled with a gray charge; then carry a leader from the tail of one case to the mouth of the other.

Globes for these wheels are made of two tin hoops, with their edges outwards, fixed one within the other, at right angles. The diameter of these hoops must be rather less than that of the wheel. Having made the globe, drive in the centre of a wheel an iron spindle, which must stand perpendicular, and its length four or six inches more than the diameter of the globe.

:

The spindle serves for an axis, on which is fixed the globe, which must staad four or six inches from the wheel round one side of each boop must be soldered little bits of tin, two inches and a half distance from each other; which pieces must be two inches in length each, and only fastened at one end, the other ends being left loose, to turn round the small portfires, and hold them on these portfires must be made of such a length as will last out the cases on the wheel. There need not be any portfires at the bottom of the globe within four inches of the spindle; as they would have no effect, but to burn the wheel: all the portfires must be placed perpendicularly from the centre of the globe, with their mouths outwards; and must be clothed with leaders so as all to take fire with the second case of the wheel; and the cases must burn two at a time, one opposite the other. When two cases of a wheel begin together, two will

Aquatic will end together; therefore the two opposite end cases Fireworks. must have their ends pinched and secured from fire. The method of firing such wheels is, by carrying a leader from the mouth of one of the first cases to that of the other; and the leader being burnt through the middle, 145 will give fire to both at the same time.

Odoriferous

loons.

Odoriferous water balloons are made in the same manwater-bal- ner as air balloons, but very thin of paper, and in diameter one inch and three-fourths, with a vent of half an inch diameter. The shells being made, and quite dry, fill them with any of the following compositions, which must be rammed in tight: these balloons must be fired at the vent, and put into a bowl of water. Odoriferous works are generally fired in rooms.

Composition I. Saltpetre two ounces, flour of sulphur one ounce, camphor half an ounce, yellow amber half an ounce, charcoal-dust three-fourths of an ounce, salt of benjamin half an ounce, all powdered very fine and well mixed.

II. Saltpetre 12 ounces, meal-powder three ounces, frankincense one ounce, myrrh half an ounce, camphor half an ounce, charcoal three ounces, all moistened with the oil of spike.

III. Saltpetre two ounces, sulphur half an ounce, antimony half an ounce, amber half an ounce, cedar raspings one-fourth of an ounce, all mixed with the oil of roses and a few drops of bergamot.

IV. Saltpetre four ounces, sulphur one ounce, sawdust of juniper half an ounce, saw-dust of cypress one ounce, camphor one-fourth of an ounce, myrrh two drams, dried rosemary one-fourth of an ounce, all moisteued a little with the oil of roses.

N. B. Water-rockets may be made with any of the above compositions, with a little alteration, to make them weaker or stronger, according to the size of the

cases.

146 A sea-fight Having procured four or five small ships, of two or with small three feet in length, make a number of small reports, ships and a fire-ship. which are to serve for guns. Of these range as many as you please on each side of the upper decks; then at the head and stern of each ship fix a two-ounce case, eight inches long, filled with a slow portfire composition; but take care to place it in such a manner that the fire may fall in the water, and not burn the rigging: in these cases bore holes at unequal distances from one another, but make as many in each case as half the number of reports, so that one case may fire the guns on one side, and the other those on the opposite. The method of firing the guns is, by carrying a leader from the holes in the cases to the reports on the decks; you must make these leaders very small, and be careful in calculating the burning of the slow fire in the regulating cases, that more than two guns be not fired at a time. When you would have a broadside given, let a leader be carried to a cracker, placed on the outside of the ship; which cracker must be tied loose, or the reports will be too slow in all the ships put artificial guns at the portholes (A).

Having filled and bored holes in two portfires for

regulating the guns in one ship, make all the rest exact- Aquatic ly the same; then, when you begin the engagement, Fireworks light one ship first, and set it a sailing, and so on with the rest, sending them out singly, which will make them fire regularly, at different times, without confusion; for the time between the firing of each gun will be equal to that of lighting the slow fires.

The fire-ship may be of any size; and need not be very good, for it is always lost in the action. To prepare a ship for this purpose, make a portfire equal in size with those in the other ships, and place it at the stern; in every port place a large portfire, filled with a very strong composition, and painted in imitation of a gun, and let them all be fired at once by a leader from the slow fire, within two or three diameters of its bottom; all along both sides, on the top of the upper deck, lay star-composition about half an inch thick and one broad, which must be wetted with thin size, then primed with meal-powder, and secured from fire by pasting paper over it; in the place where you lay this composition, drive some little tacks with flat heads, to hold it fast to the deck: this must be fired just after the sham guns, and when burning will show a flame all round the ship: at the bead take up the decks, and put in a tin mortar loaded with crackers, which mortar must be fired by a pipe from the end of the slow fire; the firing of this mortar will sink the ship, and make a pretty conclusion. The regulating portfire of this ship must be lighted at the same time with the first fighting ship.

Having prepared all the ships for fighting, we shall next proceed with the management of them when on the water. At one end of the pond, just under the surface of the water, fix two running blocks, at what distance you choose the ships should fight; and at the other end of the pond, opposite to each of these blocks, under the water, fix a double block; then on the land, by each of the double blocks, place two small windlasses; round one of them turn one end of a small cord, and put the other end through one of the blocks; then carry it through the single one at the opposite end of the pond, and bring it back through the double block again, and round the other windlass to this cord, near the double block, tie as many small strings as half the number of the ships, at any distance; but these strings must not be more than two feet long each: make fast the loose end of each to a ship, just under her bowsprit ; for if tied to the keel, or too near the water, it will overset the ship. Half the ships being thus prepared, near the other double block fix two more windlasses, to which fasten a cord, and to it tie the other half of the ships as before: when you fire the ships, pull in the cord with one of the windlasses, to get all the ships together; and when you have set fire to the first, turn that windlass which draws them out, and so on with the rest, till they are all out in the middle of the pond; then, by turning the other windlass, you will draw them back again; by which method you may make them change sides, and tack about backwards and forwards at pleasure. For the fire ship fix the blocks and windlasses between the others;