The whole is so regulated, as to weight of materials, that the machine floats, or, more probably, moves under the surface of the water; so that little more than the heads of the men are seen. This secures the men and the machine from the fire of the enemy; and as the oars must be constantly plied under water, there is less danger of their being discovered by their noise, as they approach.

Infernal machines have also been made, to be used on land. Such is the machine we are told, which was intended for the destruction of Bonaparte. They may be made to explode at a given time, by clock-work, or by a match, calculated to burn a certain time!

Sec. XIX. Of the Catamarin.

The catamarin, properly so called, is a floating raft, originally used in China, and among the Portuguese as a fishing-boat. The Indian catamarin consists of two logs of wood, upon which the natives float, and go through the heaviest surf.

The military or naval catamarin is a different thing. It is properly a case, filled with combustibles, and contrived to remain so low in the water as to be almost imperceptible. This, being towed to the building, or ship, against which the attack is to be directed, is left to explode, by means of machinery within itself, when its operation is sometimes very destructive.

English writers acknowledge, that the catamarin, submitted by the late Mr. Pitt to the English government, and which cost in its construction a considerable sum, was originally invented by our countryman, the late Mr. Fulton, of whose invention we will speak hereafter.

Some observations on a boat, named, by the French, Chelingues, and the Indian catamarin, may be seen in the Dictionnaire de l'Industrie, article Bateau.

Several diving machines have been invented in France and elsewhere. M. Castera (Archives des Découvertes, iii, p. 185) describes a plunging boat, which resembles in figure a cone. It is furnished with a reservoir, calculated to hold water, and may be filled or emptied by means of pumps. By means of glasses and copper handles, the navigator is enabled to see and to take hold of objects. It is also furnished with tubes for the transmission of the air necessary for respiration, that communicate from the interior of the vessel with the atmosphere; and a double bellows, designed as well for receiving, as expelling air. Besides oars or paddles, necessary to move it under water, there is a contrivance for detaching the boat from the reservoir, either wholly or in part, according to circumstances.

M. Castera, in a memoir on sub-marine navigation, has noticed several applications of the plunging boat, which may be seen in the Bulletin de la Société d'Encouragement, No. 71. In No. 61, of the same work, is the first notice of Castera's invention, an extract of which may be seen in the Archives des Découvertes, ii. p. 121. A description of Lutgendorf's boat may be seen in the Magazin der Erfindungen, No. 46.

Sec. XX. Of the American Turtle.

It is well known that the diving-bell, and similar contrivances, have been used for naval purposes, in connection with naval warfare.

Divers, or those who made it a business, by long habit and experience, to remain under water, and go to a great depth, were often employed in war to destroy the works and ships of the enemy. When Alexander was besieging Tyre, divers swam off from the city, under water, to a great distance, and, with long hooks, tore to pieces the mole, with which the besiegers were endeavouring to block up the harbour. The invention of the diving-bell, the campana urinatoria of some, is generally assigned to the sixteenth century; but it is evident, from the writings of Aristotle and others, that, in his time, divers used a kind of kettle to enable them to continue longer under water.

At the pearl fisheries, in the Bay of Condalzchy, in Ceylon, divers usually remain under water two minutes. There are some who can stay five minutes; and a diver from Anjano, engaged in this fishery in 1797, was able to remain six minutes under water. But their efforts are so great, that, when they come up, blood frequently issues from their mouths, ears, and nostrils. Notwithstanding this, they frequently dive from forty to fifty times a day, and bring up in a bag-net a hundred oysters each time.

It may be proper to observe, that the subject of sub-marine navigation was largely descanted upon by Mersennus, (Tractatus de Magnetis Proprietatibus), and by Bishop Wilkins (Mathematical Magic, 1648), who, by the way, is rather visionary. The conveniences and advantages he enumerates, are: 1. 'Privacy, as a man may thus go to any part of the world invisibly, without being discovered or prevented. 2. Safety, from the uncertainty of tides and tempests, &c. 3. It may be used to blow up, or undermine a navy: 4. Or to relieve a blockaded place, &c. But, with regard to the use of sub-marine vessels in war, Mr. David Bushnel, of Saybrook, Connecticut, appears to be entitled to the credit of the invention. His account of it may be seen in the Transactions of the American Philosophical Society. The intended object of this vessel was to destroy shipping, by the explosion of a magazine of gunpowder.

In Silliman's Journal of Science and Arts, vol. II, p. 94, is a communication by Mr. Griswold, on the subject of Bushnel's machine, with an account of the first attempt with it, in August, 1776, by Ezra Lee, a sergeant in the American army, to destroy some of the British ships then lying at New York. Mr. Griswold remarks, that, considering the invention of Mr. Bushnel as the first of its kind, it will be pronounced to be remarkably complete throughout in its construction, and that such an invention furnishes evidence of those resources and creative powers, which must rank him as a mechanical genius of the first order.

He has given a description of it; but the outline which we give is taken from Nicholson's Journal, quarto, iv, p. 229.

It is a decked boat, to go underwater: and several persons have gone under water many leagues. The difficulty is, to provide the persons in the boat with fresh air for respiration; and this is contrived, by having a reservoir of air, of suitable dimensions to the size of the boat, and the number of persons in it. By means of a condensing pump, the air, in this reservoir, is condensed about 400 times; and by a spring, the air is let out at intervals, as circumstances require, the carbonic acid produced by respiration being absorbed by quicklime. Within this boat are flaps, like those of a rundle, to move the boat, two rudders, one vertical, the other horizontal, and a pump to empty the hold, or air reservoir. The person within, can, at pleasure, come to the top of the water. The different experiments made by Mr. Bushnel may be seen in the Transactions referred to, or in Nicholson's Journal, quarto, iv, 229.

During the late war, Mr. Fulton, Mr. Mix, and some others, made various experiments with submarine machines; and during the revolution, the incendiary kegs, well known by the name of the "battle of the kegs," excited no small attention, and, had it not been for some unforeseen circumstance, they would, in all probability, have produced the effect for which they were intended.

Of Bushnel's vessel, we may observe, that, in the fore part of the brim of the crown, as it is called, was a socket, and an iron tube passing through the socket. The tube stood upright, and could slide up and down in the socket, six inches. At the top of the tube was a wood screw, fixed by means of a rod, which passed through the tube, and screwed the wood screw fast upon the top of the tube. By pushing the wood screw up against the bottom of a ship, and turning it at the same time, it would enter the planks. When the wood screw was firmly fixed, it could be cast off by unscrewing the rod, which fixed it upon the top of the tube.

Behind the submarine vessel, was a place, above the rudder, for carrying a large powder magazine. This was made of two pieces of oak timber, sufficiently large, when hollowed out, to contain 150 lbs. of powder, (130 lbs. according to Griswold,) with the apparatus used in firing it, and was secured in its place by a screw, turned by the operator. A strong piece of rope extended from the magazine to the wood screw above mentioned, and was fastened to both. When the wood screw was fixed, and to be cast off from its tube, the magazine was to be cast off likewise by unscrewing it, leaving it hanging to the wood screw; it was lighter than the water, that it might rise up against the object, and apply itself when fastened.

Mr. Griswold remarks, that the most difficult point of all to be gained, was to fasten this magazine to the bottom of a ship.

Within the magazine, was a machine, constructed to run any proposed length of time under twelve hours. When it had run out its time, it unpinioned a strong lock resembling a gun-lock, which gave fire to the powder. This apparatus was so pinioned, that it could not possibly move, till, by casting off the magazine from the vessel, it was set in motion.

This skilful operator could swim so low on the surface of the water, as to approach very near a ship in the night without fear of discovery, and might, if he chose, approach the stem or stern above water, with very little danger. He could sink very quickly, keep at any depth he pleased, and row a great distance in any direction he desired, without coming to the surface; and, when he rose to the surface, he could soon obtain a fresh supply of air; when, if necessary, he might descend again and pursue his course. The projector found some time and attention to be requisite for the gradual instruction of this operator, and, after various attempts, he found one, on whom he thought he could depend. He sent this man from New York to a 50 gun ship, lying not far from Governor's island. He went under the ship, and attempted to fix the wood screw in her bottom, but struck, as he supposed, a bar of iron, which passes from the rudder's hinge, and is spiked under the ship's quarter. Had he removed a few inches, which he might have done without rowing, the projector has no doubt but he might have found wood, where he might have fixed the screw; or if the ship were sheathed with copper, he might easily have pierced it. But, not being well skilled in the management of the vessel, in attempting to row to another place, he lost the ship. After seeking her in vain some time, he rowed to some distance, and rose to the surface of the water, but found day light had advanced so far, that he durst not renew the attempt. He says, he could easily have fastened the magazine under the stern of the ship above the water, as he rowed up to the stern, and touched it before he descended. Had he fixed it there, the explosion of 150 lbs of gunpowder (the quantity contained in the magazine) must have been fatal to the ship. In his return from the ship to New York, he passed near Governor's island, and thought he was discovered by the enemy on the island. Being in haste to avoid the danger he feared, he cast off the magazine, as he imagined it retarded him in the swell, which was very considerable. After the magazine had been cast off an hour, the time the internal apparatus was set to run, it blew up with great violence.

Mr. Griswold gives an account of an attempt to destroy a ship of war; and having received his information from Mr. Lee, one of the adventurers, we have thought proper to introduce it from that source.

"It was in the month of August, 1776, when Admiral Howe lay with a formidable British fleet in New York bay, a little above the narrows, and a numerous British force upon Staten Island, commanded by General Howe, threatened annihilation to the troops under Washington, that Mr. Bushnel requested General Parsons, of the American army, to furnish him with two or three men to learn the navigation of his new machine, with the view of destroying some of the enemy's shipping.

"General Parsons immediately sent for Lee, then a sergeant, and two others, who had offered their services to go on board a fire ship; and on Bushnel's request being made known to them, they enlisted themselves under him for this novel piece of service. The party went up into Long Island sound with the machine, and made various experiments with it in the different harbours along shore; and after having become pretty thoroughly acquainted with the mode of navigating it, they returned through the sound; but, during their absence, the enemy had got possession of Long Island and Governor's Island. They, therefore, had the machine conveyed by land across from New Rochelle to the Hudson river, and afterwards arrived with it at New York.

"The British fleet now lay to the north of Staten Island, with a large number of transports, and were the objects against which this new mode of warfare was destined to act. The first serene night was fixed upon for the execution of this perilous enterprize, and sergeant Lee was to be the engineer. After a lapse of a few days, a favourable night arrived, and, at 11 o'clock, a party embarked in two or three whale boats, with Bushnel's machine in tow. They rowed down as near the fleet as they dared, when sergeant Lee entered the machine, was cast off, and the boats returned.

"Lee now found the ebb tide rather too strong, and before he was aware, had drifted him down past the men of war. He, however, immediately got the machine about, and by hard labour at the crank for the space of five glasses by the ship's bells, two and a half hours, he arrived under the stern of one of the ships at about slack water. Day had now dawned, and by the light of the moon he could see the people on board, and hear their conversation. This was the moment for diving: he accordingly closed up over head, let in water, and descended under the ship's bottom. He now applied the screw, and did all in his power to make it enter; but owing probably in part to the ship's copper, and the want of an adequate pressure, to enable the screw to get a hold on the bottom, his attempts all failed. At each essay, the machine rebounded from the ship's bottom, not having sufficient power to resist the impulse thus given to it. He next paddled along to a different part of her bottom, but, in this manœuvre, he made a deviation, and instantly rose to the water's surface on the east side of the ship, exposed to the increasing light of the morning, and in imminent hazard of being discovered. He immediately made another descent, with a view of making one more trial; but the fast approach of day, which would expose him to the enemy's boats, and render his escape difficult, if not impossible, deterred him; and he concluded the best generalship would be, to commence an immediate retreat. He now had before him a distance of more than four miles to traverse, but the tide was favourable. At Governor's island, great danger awaited him; for his compass having got out of order, he was under the necessity of looking out from the top of the machine very frequently, to ascertain its course, and at first made a very irregular zigzag track. The soldiers at Governor's island espied the machine, and curiosity drew several hundreds upon the parapet to watch its motions. At last a party came down to the beach, shoved off a barge, and rowed towards it. At that moment, sergeant Lee thought he saw his certain destruction, and as the last act of defence, let go the magazine, expecting they would seize that likewise, and thus all would be blown to atoms together. Providence, however, otherwise directed it: the enemy, after approaching within 50 or 60 yards of the machine, and seeing the magazine detached, began to suspect a yankee trick, took alarm, and returned to the island. Approaching the city, he soon made a signal; the boats came to him, and brought him safe and sound to the shore. The magazine, in the mean time, had drifted past Governor's island into the East river, where it exploded with tremendous violence, throwing large columns of water, and pieces of wood that composed it, high into the air. General Putnam, with many other officers, stood on the shore, spectators of this explosion.

"In a few days, the American army evacuated New York, and the machine was taken up the North river. Another attempt was afterwards made by Lee, upon a frigate that lay opposite Bloomingsdale. His object now was to fasten the magazine to the stern of the ship, close at the water's edge. But while attempting this, the watch discovered him, raised an alarm, and compelled him to abandon his enterprize. He then endeavoured to get under the frigate's bottom; but in this he failed, having descended too deep. This terminated his experiments."

With regard to diving bells, several machines, for the purpose of descending under water, &c. have been invented. Some experiments have been made by the French with similar contrivances, without any adequate result; and the difficulty of carrying them into execution, in real practice, will prevent their introduction.

Dr. Caustic, (Terrible Tractoration, p. 65), in a note, in reference to Bushnel's invention, observes, that if you consult the Transactions of the American Philosophical Society, "you will see what Mr. D. Bushnel, of Connecticut, has done, and had like to have done, by virtue of submarine explosions. You will find, that several English ships have been put in jeopardy, and one schooner actually blown up and demolished by Mr. Bushnel's submarine explosions."[33]

Sec. XXI. Of the Torpedo.

The late Mr. Fulton applied himself to the improvement of the Turtle during the late war, and brought it to such perfection, that if it came in contact with a ship's bottom, it would inevitably blow up the vessel. From the account we have given of the turtle, we may readily imagine the construction of the torpedo. These were of several kinds; some (or rather the magazine attached to them,) were designed to be screwed under the bottom, and others to explode by coming in contact with the vessel, or any resisting body. The time of explosion was so determined, by clock-work machinery, in the manner of Bushnel's contrivance that it would invariably explode at the minute or second required.

Mr. Fulton wrote a number of essays on this torpedo, and other contrivances for annoying the enemy, such as the harpoon, &c. The torpedo, at which the British ships, stationed on our coast, were so much alarmed, is in fact a powerful weapon of destruction. It is to be observed, that the magazine, accompanying the bell, in some instances, was detached; so that the latter was removed out of danger, when the former was fixed to the ship's bottom. In order to prevent the torpedo from floating against the sides of a vessel, the precaution of having netting spread at some considerable distance round the vessel, and of keeping up a constant guard of boats, which were rowed round the ship both day and night, was used. Not having the writings of Mr. Fulton before us, we can give no precise description of his improvements. They are described to be an apparatus, of which the principal piece is a copper box, and prepared with an interior spring, which sets fire to the powder; at the same time that the whole is enclosed in a covering of cork, or some other light wood, to make the torpedo float under the surface of the water.

It will be sufficient to remark, that they have produced the effect of causing a constant, and, in our opinion, painful anxiety to the British. Of this we have abundant proof. We may add, however, the result of some of the experiments, by which it will appear, that they are eminently calculated, like the infernal machine, to produce death and destruction.

In consequence of some essays, published by Mr. Fulton, on the practicability of destroying ships by torpedoes, several persons turned their attention to this subject; among whom was a Mr. Mix of the navy. Mr. Mix's intention was to destroy the ship of war Plantagenet, of 74 guns, lying in Lynnhaven bay. Having made a torpedo, Mr. Mix, accompanied by two gentlemen, one of whom was a midshipman, proceeded in a boat, on the night of the 24th of July, 1813, and, having reached within 100 yards of the ship, dropped the torpedo. It was swept along by the side, but exploded a few seconds before it would have come in contact with the vessel. It produced, however, great consternation and confusion on board the vessel, and induced several of the crew to take to their boats. The ship was greatly agitated, and some damage done by the violent motion of the water. The noise, occasioned by the explosion, was loud and tremendous; and the appearance of the water, thrown up in a column of thirty or forty feet high, awfully sublime. It has not been ascertained, that any lives were lost.

The case of a Mr. Penny, of Easthampton, Long Island, is connected with the subject of torpedoes. He was carried on board the Ramilies, and put in irons; because his name had been entered on the books of one of the frigates, as having been "employed in a boat, contrived for the purpose, under the command of Thomas Welling, prepared with a torpedo, to destroy this (Capt. Hardy's) ship."

The affair of Stonington, also, shows, that the British were determined to punish the inhabitants for having, as captain Hardy expresses it, prepared torpedoes; and the captain stated, in his reply to the deputation from the town, that the bombardment should cease, in case the inhabitants would engage that no torpedoes should be fitted out by them. No torpedoes, however, were fitted out at Stonington.[34]

Mr. Fulton made a number of experiments with the torpedo, in the harbour of New York; and one vessel was completely cut in two. These experiments were very satisfactory to all who witnessed them.

The greatest difficulty he experienced was in giving them a proper direction, so as to hit the vessel intended to be destroyed. This he acknowledged to a friend, professor Eaton, of Troy, who informed us of the fact. He entertained no doubt whatever of the effect of the torpedo, when once brought in contact with a vessel.

At Havre, in France, Mr. Fulton constructed a sub-marine boat, sufficient to contain several men, and air for eight hours, and strong enough to bear submersion to the depth of one hundred feet, if necessary. In this boat, he remained an hour under water, made half a league of way in that time, with his boat horizontally situated, and at various depths, where he found that the compass traversed exactly, as on the surface. To the boat he attached a machine, by means of which he blew up a lighter in Brest Harbour.

While in France, in the time of the Republic, Mr. F. directed his attention to this subject. His Bateau-poisson, described in the Dictionnaire de l'Industrie, vol. i, p. 265, is of the same character. A number of experiments performed with it are given.

Sec. XXII. Of the Marine Incendiary Kegs, &c.

We purpose to notice, under this head, two contrivances, which have been used, the one in the revolution, and the other, during the late war with Great Britain.

The piece of poetry, called the Battle of the Kegs, written by the late Francis Hopkinson, Esq. of Philadelphia, narrating the incendiary kegs, is founded on this contrivance.

For the purpose of destroying the shipping at Philadelphia, which was then in possession of the British, some forty or more kegs were fitted up at Burlington, N. J. or in its neighbourhood, containing a quantity of gunpowder. These kegs were connected in such a manner, that, while they formed one float, when one exploded, the whole would go off. This arrangement was also made with another, if our information is correct, which consisted in a trigger connected with a gun-lock, (one or more kegs having the same); so that, when the triggers went off, by the casks coming against any thing, in floating down the tide, the whole would explode at the same time. There is one of the original kegs in the magazine of Fort Mifflin. We apprehend, however, that the contrivance was more like that of clock-work, set to a given time, like the torpedo of Fulton; but of this we have no certain account. These kegs were towed down the river, within a mile or two of the city, and were seen about sunrise opposite to it. They did no execution; but, if they had been taken to a given spot, instead of being left to the direction of the running current, and then properly adjusted, no doubt the effect would have been as the contriver calculated. It excited, however, no small sensation at the time.

Of the other contrivance, we have the following account: A Mr. Scudder (History of the late War, &c. p. 187) formed a design of destroying the British ship Ramilies, of 74 guns, off New London. For this purpose, 10 kegs of powder were put into a strong cask, with a quantity of sulphur mixed into it. At the head of the cask were, fixed two gun-locks, with cords fastened to the triggers, and to the under side of the barrels in the hatchway; so that it was impossible to hoist the barrels, without springing the locks each side of the powder. On the top were placed a quantity of turpentine and spirits of turpentine, which in all probability were sufficient to destroy any vessel that ever floated. These kegs were put on board the smack Eagle, which sailed from New York on the 15th of June, for New London; but which the crew abandoned, on being pursued by the boats of the enemy. It was expected, that the vessel would be brought alongside the Ramilies, and, by exploding, destroy that ship. The wind dying away, and the tide being against them, she could not, very fortunately for the enemy, be brought alongside. When the Eagle exploded, there were four boats alongside, and a great many men on board of her. After the explosion, there was not a vestige of the boats to be seen. A body of fire rose to a vast height, and then burst like a rocket. Every man, near or about her, was probably lost, as the boats sent from the Ramilies were seen to return without picking up anything.

In relation to similar enterprizes, what could have been a more daring and hazardous enterprize, than that of lieutenants Wadsworth, Summers, &c. who, by a previous agreement, determined, if they were likely to be captured by the Turks, to blow themselves up in the fire-ship, which they had prepared to destroy the enemy's shipping, in the harbour of Tripoli? Their fate is too well known, lamentable as it is!

The marquis of Worcester, in his Century of Inventions, inventions nine and ten, speaks of certain contrivances for the destruction of vessels, which seem to have been of the kind mentioned: viz. "An engine, portable in one's pocket, which may be carried and fastened on the inside of the greatest ship, tanquam aliud agens; and, at an appointed minute, though a week after, either of a day or night, it shall irrecoverably sink that ship;" and "a way from a mile off, to drive and fasten a like engine to any ship, so as it may punctually work the same effect, either for time or execution."

Sec. XXIII. Of Sea Lights.

The fanaux de mer, or sea lights, are so called, from the particular application of this fire.

It is sometimes required at sea to throw light upon the water, and around the vessel, in order to perceive the approach of an enemy. This is effected by the composition for sea lights.

A tube must be formed of not less than three inches in diameter, and eleven inches in length. A shield is then adapted, of four times the exterior diameter of the tube or case, which shield is to be made of wood, and attached at about the distance of one-fourth of the length of the tube, and near the end of the orifice.

The case or tube is then charged with the following composition:

Composition for Sea Lights.

The tube, which may be made of iron, pasteboard, or wood, by boring it out, after being charged, is primed in the usual manner, inserting in the end, at the same time, a piece of quick-match. When dried, it is wrapped in paper for better preservation.

Sec. XXIV. Of Signal and War-Rockets.

Rockets, we have said, are cylindrical cases, formed generally of pasteboard, and filled with a peculiar composition, made of meal-powder, saltpetre, sulphur, and charcoal; or without powder, and sometimes with the addition of pulverized cast iron. In some, as the Congreve rocket, iron cases are substituted for those of paper. The outer diameter is usually from one and a half to two inches, the length of the charge five diameters, and the interior diameter two-thirds as much as the exterior. The tools necessary are, a rod or former of wood, to mould the case upon; an artificer's tool to roll the paper close; a conical spit or piercer, by means of which the rocket when loaded has a hollow through the middle, which piercer should be four and two-thirds times as long as the outer diameter of the rocket, one-third of this diameter at the base, and one-sixth at the small end; three rods for loading, having a conical aperture to receive the piercer, and one massive; and a ladle or measure, whose diameter is equal to that of the inside of the rocket, and its length three times as much. The construction of the cartouch case, or paper cylinder, consists in using pasteboard of three or more thicknesses, which is rolled on the former, until the case becomes sufficiently thick. The choaking of the cylinder is performed by means of a cord, of three lines in diameter, one end of which is firmly fixed into a wall, and the other tied to a stick, against which the artificer who bestrides the cord rests. The rocket is loaded or charged, by introducing at a time, a ladle full of composition, first fixing the case over the piercer, and using the appropriate rammer and mallet, in the manner stated, &c.[35]

Signal rockets are sometimes trimmed with serpents, stars, and petards. The serpents are made of cases in the manner already mentioned; viz. by rolling playing cards in the direction of their length, upon a former, three lines in diameter, and covered with three coats of paper, the last of which is pasted. The cases are choaked at one end, and in the niche is placed a strand of tow, and a priming of meal-powder, moistened with brandy. They are loaded, by means of a rod, three-fourths full of the composition, and again choaked at half their height. The remainder is filled up with powder, to make a report. If a serpent with stars is to be made, only half the case is filled with the serpent-composition, and the rest with that for stars. Serpents are placed upright in the pot, the priming down.

Composition for Serpents, for trimming Signal Rockets.

The star composition is the same as before given.[36] It is mixed and made into balls or cubes, in the same manner. The petards or crackers are small cubes of paper, filled with grained gunpowder. They are wrapped with two layers of good thread, which is drawn tight in every direction. They are dipped in tar to give them more consistence, and pierced and primed with quick match. We have already given the theory of the flight of rockets in the first part of this work; and also the opinions of Mariotte and Dr. Desaguliers. On this head, therefore, further observation seems unnecessary We have said, however, that it is necessary, for giving the rocket a sufficient degree of motion, that the powder within the rocket be bored with a tapering cavity from the choke, and at the choke this cavity must be as wide as the choke itself, and at the further end, not more than half that width. The length of this bore must be but one inner diameter of the rocket, short of the whole height to which the rocket is rammed. The use of this bore, it is to be observed, is to increase the surface, that takes fire at once; that a greater body of fire may issue out of the mouth of the rocket. From the vehemence with which the fire issues out, the rocket receives its motion. We have seen, that rockets are used in all fire-works that have motion; for cases charged give motion to wheels of various kinds, and act on the same principle. Such works as are thrown into the air after the manner of bombs, are, however, an exception.

The rocket-stick is a necessary appendage. When very heavy, to prevent mischief by their fall, they now bore the sticks, and fill them with powder, that they may shiver in the air before they fall.

That the stick keeps the rocket perpendicular is obvious. If the rocket should begin to tumble, moving round a point in the choke, as being the common centre of gravity of rocket and stick, there would be so much friction against the air, by the stick between the centre and the point, and the point would beat against the air with so much velocity, that the reaction of the medium would restore it to its perpendicularity. When the composition is burnt out, and the impulse upwards has ceased, the common centre of gravity is brought lower towards the middle of the stick. Hence the velocity of the point of the stick is decreased, and that of the point of the rocket increased; so that the whole will tumble down, with the rocket end foremost. During the combustion of the rocket, the common centre of gravity is shifting and getting downwards, and faster and lower as the stick is lighter.

In the Philosophical Transactions, (vol. xlvi, p. 578) and Robins's Mathematical Tracts, (vol. i, p. 317, &c.) are sundry experiments, and observations concerning the flight of rockets; and as these experiments appertain more to military purposes, the following extracts may, on that account, be useful.

Mr. Robins, considering the great use that may be made of rockets, in determining the position of distant places, and in giving signals for naval and military purposes, procured some, with a view of ascertaining the height to which they rise, and the distance at which they may be seen. The greatest part of them did not rise to above four hundred yards; one to about five hundred; and one to six hundred yards nearly. The greatest distance at which these were observed, was from thirty-five to thirty-eight miles. Others were fired at a different time, one of which rose to six hundred and ninety yards; and it was observed, that the largest, which were about two and a half inches in diameter, rose the highest. In some subsequent experiments, conducted by Mr. Da Costa, Mr. Banks, &c. it was found, that, of two rockets, of about three and a half inches in diameter, one rose to about eight hundred and thirty-three, and the other to 915 yards. In another trial, a rocket of four inches in diameter rose to one thousand one hundred and ninety yards. In other experiments, a rocket of one and a half inches rose to seven hundred and forty-three yards; one of two inches to six hundred and fifty nine; one of two and a half inches to eight hundred and eighty; another of the same size to one thousand and seventy-one; one of three inches to one thousand two hundred and fifty-four; one of three and a half inches to one thousand one hundred and nine; and one of four inches rose to seven hundred yards, and, turning, fell to the ground before it went out. Besides these, there was one of the rockets of "twenty-four inches in diameter,"[37] which rose to seven hundred and eighty four yards, and another of the same size, to eight hundred and thirty-three yards. From these experiments, it is inferred, that rockets from two and a half to three and a half inches in diameter, are sufficient to answer all the purposes for which they are intended; and they may be made to rise to a height, and to afford a light capable of being seen to considerably greater distances than those just mentioned.

Before we mention the war-rockets of Congreve, it may not be improper to speak of the Indian rockets, which are used by the native troops of India, and which were employed against the British, with great effect, during the seige of Seringapatam in 1799. These rockets are made of iron, and are lashed to a bamboo cane. The weight is seldom more than two pounds, or less than one. The fougette, or Indian rocket, resembles in shape a sky-rocket, whose flight is gradually brought to run along a horizontal direction. By throwing several fougettes into parks of artillery, and upon caissons, &c. considerable damage might be occasioned from the fire, which would inevitably be communicated to some part. A fougette forces itself immediately forward, cuts as it penetrates, by the formation of its sides, which are filled with small spikes, becomes combustible, and on fire at all its points, and possesses within itself a thousand different means, by which it can adhere to whatever object it is destined to set on fire or destroy. A French writer even asserts, that this weapon would be more effectual, because it might be more variously applied, to defend the mouth of a harbour against an enemy's shipping, than red-hot balls can ever prove; and we are also told, that, by means of their natural velocity, they would do more execution, in a less space of time, than the most active piece of ordnance could effect; and they would also require fewer hands, as the only necessary operation would be to light and dart them forward.

The fougette, called also in French the Baguette à feu, has received improvements in France, which we will notice hereafter. In favour of these improvements and their application, we are told, that, to do execution at a distance, especially in sea-fights, fougettes may be so made as that they may reach shipping at a great distance, and with a given velocity.

The Congreve rocket is a new species of war-rocket, invented by Sir William Congreve. This incendiary rocket drew the attention of the European nations, after the attack of the British on Copenhagen; where, we are informed, they did incredible execution. This rocket may be considered to be a carrier of fire. Their effect, however, in the Chesapeake, and elsewhere, during the late war, was very trifling. They seemed, in fact, little calculated to injure and more to intimidate.[38] They differ from the common rocket as well in their magnitude and construction, as in the powerful nature of their composition; which is such, that without the encumbrance of any ordnance, (the rocket containing the propelling power wholly within itself), balls, shells, case-shot and carcasses, may be projected to the distance of one thousand to three thousand yards. The principle of projectile force is so greatly increased, as not only to triple the flight of small rockets so formed, but also to allow of the construction of rockets of such dimensions, as, on the ordinary principles of combination, would not even rise from the ground, and of such powers of flight and burthen, as have hitherto been considered altogether impracticable.

On the basis of this increase of power, Congreve has succeeded in making this rocket. They are formed of various dimensions, as well in length as in caliber, and are differently armed, according as they are intended for the field, or for bombardment and conflagration; carrying in the first instance either shells or case shot, and in the second, for the purpose of destroying shipping, buildings, stores, &c. a peculiar species of composition, which never fails of destroying every combustible material with which it comes in contact. The latter are called carcass-rockets, and were first used at Boulogne in 1805, after many experiments, which were made by Congreve, at Woolwich. The attack in 1806 was merely desultory, in which not more than 200 rockets were fired. The town was set on fire by the first discharge, and continued burning for near two days. After the affair at Copenhagen, which established their reputation, it appears that a committee of officers, who had witnessed their effect in that bombardment, pronounced them to be "a powerful auxiliary to the present system of artillery."

At the seige of Flushing, they appear to have been used with success, and general Monnet, the French commandant, made a formal remonstrance to lord Chatham respecting the use of them in that bombardment. The rocket system was also tried with success, and the crown prince of Sweden was the first general, who bore testimony to their effects in this service. At the memorable battle of Leipzig, they proved, we are informed, a powerful weapon, and also, when the British army under Wellington, crossed the Adour. In 1814, a rocket-corps was established in the British service.

General de Grave transmitted, to the Society of Encouragement of Paris, a Congreve rocket, or an English incendiary rocket, which was found on the French coast. M. Gay-Lussac examined it. The case was made with gray paper, and painted. The inflammable matter was of a yellowish-gray, and the sulphur was distinguishable with the naked eye. It burnt with a quick flame, and exhaled sulphurous acid gas.

According to his analysis, (Archives des Découvertes, ii, 303), the composition gave

Gay-Lussac, after determining the proportions of the constituent parts, made a composition of a similar kind, and charged a case, which exhibited the same properties as the English rocket.

The great general point of excellence of the rocket system, if we may judge from the account of English writers, is the facility with which all the natures of this weapon may be conveyed and applied. Its peculiar applicability to naval bombardment is said to rest on this property, that there is no reaction, no recoil in the firing of the largest rocket; so that by this means carcasses, equal to those projected by the largest mortars, may be thrown from the smallest boats. Its peculiar fitness for land service is, that it is a description of extremely powerful ammunition without ordnance, so that the burthen of mortars and guns is dispensed with, and all that is to be carried is actual available missile matter, capable of range, and of many of the most important effects of the heaviest artillery. The rocket system, as a system of ammunition without ordnance, is highly extolled by British writers.

We will now speak of their construction. All rockets designed for service are cylindrical, having strong metallic cases, and armed, as we before observed, either with carcass composition for bombardment and conflagration, or with shells and case shot for field service. They are, however, of various weights and dimensions, from the eight-inch carcass or explosion rocket, weighing nearly three hundred weight, to the six pound shell rocket, which is the smallest size, used in the field. The sticks, which are employed for regulating their flight, are also of different lengths, according to the size and service of the rocket; and which, for the convenience of carriage, are stowed apart from the rocket, and so contrived as to consist of two or more parts, which are connected to it, and to each other, when requisite, with the utmost expedition. The 32 pounder rocket carcass, which is the nature hitherto chiefly used for bombardment, will range 3000 yards with the same quantity of combustible matter as that contained in the 10 inch spherical carcass, and 2500 yards with the same quantity as that of the 13 inch spherical carcass. The 12 pounder rocket case shot, which is so portable that it may be used with the facility of musketry, has a range nearly double that of field artillery, carrying as many bullets as the 6 pounder spherical case. We may remark here, that the projectile force of the rocket is well calculated for the conveyance of case shot to great distances; because, as it proceeds, its velocity is accelerated instead of being retarded, as happens with any other projectile; while the average velocity of the shell is greater than that of the rocket only in the ratio of 9 to 8. Independent of this, the case shot conveyed by the rocket admits of any desired increase of velocity in its range by the bursting of powder, which cannot be obtained in any other description of case.

Rocket ammunition is divided into three classes, heavy, medium, and light; the former including all those above 42 lbs., which are denominated according to their caliber, as eight-inch, seven-inch, &c. rockets; the medium including all those from 42 lbs. to 24 lbs.; and the light embracing from 18 pounder to 6 pounder inclusive.

The carcass-rockets are armed with strong iron conical heads, containing a composition as hard and solid as iron itself, and which, when once inflamed, cannot be extinguished. A 32 pounder carcass rocket will penetrate 9 feet in common ground. They have been known to pierce through several floors, and through the sides of houses. For field service, the 24, 18, 12, and 6 pounders are commonly used. The ranges of the eight-inch, seven-inch, and six-inch rockets, are from 2000 to 2500 yards, and the quantity of combustible matter, or bursting powder, from 25 lbs. to 50 lbs. These sized rockets are equally efficient for the destruction of bomb proofs, or the demolition of strong buildings. The largest rocket that has yet been constructed has not exceeded 300 weight. It is proposed, however, to make them from half a ton to a ton in weight.

The 42 and 32 pounders, which are used in bombardment, will convey from 7 lbs. to 10 lbs. of combustible matter each, and have a range of upwards of 3000 yards. The 24 pounder is equal to the propelling of the coehorn shell, or 12 pounder shot. It is, from the saving in weight, generally preferred to the 32 pounder. The eighteen-pounder, which is the first of the light nature of rockets, is armed with a nine pound shot or shell; the twelve-pounder, with a six do.; the nine-pounder, with a grenade; and the six-pounder, with a 3 lb. shot or shell.

The following table presents a general view of the ranges, elevations, and other particulars of several of the most useful descriptions of Congreve rockets.

From the preceding table, it will be seen, that the 32 pounder carcass rocket will range 3000 yards, with the same quantity of combustible matter as that contained in a ten-inch spherical case, and 2500 yards, with the same quantity as that of the thirteen-inch spherical carcass. The twelve pounder case-shot rocket, which is so portable that it may be used with the facility of musquetry, has a range nearly double that of field artillery, carrying as many bullets as the six pounder spherical case: add to which, that, from the nature of the combination of the rocket, these bullets are projected from it in any part of its track, with an increase of velocity, by which its operation becomes frequently more destructive at that point, where any different species of ammunition ceases to be effective. Of this description of rocket-case-shot, one hundred soldiers will carry into action, in any situation where musquetry can act, 300 rounds, and 10 frames for discharging them; from each of which, four rounds may be fired in a minute. Of the same description of case-shot, four horses will carry 72 rounds, and four frames; from which may be fired 16 rounds in a minute. The rockets used by cavalry are twelve pounders, armed with a 6 pounder shell or case shot; each horse carrying four of these rockets. To detail the arrangement of the rocket corps, the weight of ammunition carried by the troop horse, and other particulars, would require more space than we can conveniently appropriate to these subjects.

We may remark, however, that the heavier species of rockets, as the 32 pounder or 24 pounder, as also the 18 and 12 pounders, are sometimes carried in cars of a peculiar description; which not only convey the ammunition, but are contrived also to discharge each two rockets in a volley, from a double iron-plate trough. This trough is of the same length as the boxes for the sticks, and travels between them; but being moveable, may, when the car is unlimbered, be shifted into its fighting position, at any angle from the ground ranges, or point blank, up to 45°, without being detached from the carriage. The limbers are always in the rear. The rockets are fired with a port-fire and long stick.

When used by infantry, one man in ten, carries a frame of a very simple construction, standing on three legs like a theodolite, when spread. It is mounted at top with an open cradle, from which the rockets are discharged, either for ground ranges, or at any required elevation.

When they are used for bombardment, they are discharged from frames of a different, though simple, construction; and, in many cases, the frames are dispensed with, as they are thrown from a battery, erected for the purpose.

For the defence of a pass, or for covering the retreat of an army, the rockets are laid in batteries of 100 or 500 in a row, according to the extent of the ground to be protected. One man may fire the whole.

With regard to their use in the naval service, some additional remarks may be interesting.

We observed, that, in consequence of there being no reaction in these projectiles on the point of discharge, rockets may be used in the smallest boats of the navy. These rockets carry a quantity of combustible matter, and, according to the ordinary system, would require to be thrown from the largest mortars, and from ships of very heavy tonnage. The 12 and 18 pounder have been fired from a four-oared gig. They may be made to ricochet in the water at low angles. In boarding, they have been recommended, to be thrown into the port holes of the enemy. They have also been recommended for fire-ships, in order to produce an extensive and devastating fire among the ships of the enemy.

Besides the advantages, which rockets possess, and of which we have spoken; namely, that it is a species of projectile, containing within itself the propelling power, by which heavy ordnance is dispensed with, and that an extensive fire may be kept up, by a few men, against any important point; there is another advantage said to be peculiar to them; viz. that they may be employed in a variety of cases, in which the usual artillery, from the nature of the ground, or other impediments, cannot be rendered effective; and that, in several bombardments, in consequence of their trifling reaction, they may be thrown from cutters and small boats, and, therefore, from points, which could never be approached by the vessels, usually employed in that service. With respect to the expense of the formation of war-rockets, calculations have been made, by which it appears, that their cost is less than the usual expense of carcasses.

We are informed on this head, that it is the cheapest of all ammunition, depending on the projectile force of gunpowder. For a 32 pounder carcass rocket costs only 1l. 1s. 11d. complete for service, and its equivalent, the 10 inch spherical carcass, with the charge of powder necessary to convey it 3000 yards, which power is contained in the rocket, costs 1l. 2s. 7d., independent of any charge for the mortar, mortar bed, platform, difference of transport, &c. A vessel of 300 tons will carry 5000 of them at least. But the comparison, as to the expense, is still more in favour of the rocket, when compared with the larger nature of carcasses. The 15 inch spherical carcass costs 1l. 17s. 11¹/₂d. to throw 2500 yards; while its equivalent rocket costs but 1l. 5s. being a saving on the first cost, of 12s. 11¹/₂d.

Notwithstanding all the encomiums, bestowed on the Congreve rockets by the English, the French entertain a different opinion of them. For the following remarks, we are indebted to Ruggeri, (Pyrotechnie Militaire, p. 278), by which it appears, that Congreve was not the original inventor. He acknowledges, however, that they experienced the sad effects of them; and we do not offer this remark with any sort of prejudice, but as an acknowledgment, that the French experienced their "sad effects." Ruggeri says, that the Congreve rocket is nothing more than he described in his Elements of Pyrotechny five years before they were known to the English. It is, therefore, wrong, he adds, that we regard it as an English invention. It was invented, says he, by a naval officer at Bordeaux, and ought not, he further remarks, to be regarded as a useful weapon in war. The reason he gives is, that its utility must depend upon places and circumstances. If it is required, he adds, to attack a fleet, we must employ two or three hundred before making any impression; because we cannot direct a firing rocket, as a cannon or ball. This is certainly a great inconvenience. He makes the cost also much greater than the English calculation; namely, for a single one of them ten times more than for a red-hot shot. Ruggeri, however, is candid enough to say, that, notwithstanding he differs in opinion, he is far from opposing any trials or experiments, made with the view of improving or perfecting it; but is decidedly of opinion, that it can never be employed at sea with the same advantage as bombs and cannon-ball.

Ruggeri published, in the Journal of Paris, in September, 1809, a letter, in reply to a writer, who had published some reflections on incendiary rockets, from which, as it throws some light on this subject, we shall here introduce a few extracts:

"Although Monsieur, the cannonier of Ostend, may not have given the precise construction of the rocket, which we name the sky-rocket, and of which the English have made so criminal a use, I will commence at first by assuring you, that I coincide perfectly with him, in the preference he gives to howitzes, bombs, and other projectiles, which are used by civilized nations. He has very satisfactorily demonstrated their advantages over the Congreve rocket. I will only add, that bombs and howitzes have also the advantage of being one-fifth cheaper, and projected with greater facility.

"The Congreve rocket cannot be of any particular advantage, because it only carries fire to the place where it falls; and if we wish to use them against any vessel whatever, it is impossible to assure ourselves of a direction on a given point, as many difficulties occur in projecting them.

"The merit of the invention of these rockets does not belong to the English.

"This invention was made by a Frenchman, a captain of a privateer, who made the first attempt to use them about seventeen years since, (1795).

"The English have perfected, or rather have modified this rocket.

"It is sometime since I offered a kind of bomb, which may be used with more facility than the common kind. This bomb has the advantage over the Congreve rocket: 1st, Because it is less troublesome to use; 2dly, It may be made of any diameter or size, and consequently suited to all calibers; 3dly, The place and time of its fall is readily determined; and fourth, and lastly, It bursts into pieces, and attaches itself to all combustible bodies, with which it meets.

"It remains for me to say, that it is not the powder which moves the rocket, but a composition almost as strong. The powder, which is used in the Congreve rocket, is intended to destroy the machine after it has produced its destructive effects." See Pyrotechnie Militaire, p. 278.

The difference between incendiary rockets, and common signal rockets, is in the interior. Instead of the furniture, or garnishing pot and head, a conical head of sheet iron is substituted, in which several holes are made to suffer the composition it contains to burn more readily. The composition is the same as that for fire-rockets; but is coarsely pulverized, and mixed with an equal quantity of the composition of fire-lances. These rockets are employed with advantage to burn a city, or vessels in a harbour. The cone, with which they are capped, enables them to penetrate the roofs of houses, and set them on fire.

Sec. XXV. Sky-Rockets (Meurtrières.)

The sanguinary or murdering rocket is made in the same manner as the preceding. They have neither head nor pot; but, in their place, they are furnished with a cone of beaten or solid iron. This cone is the appendage, or weapon, which produces such destructive effects. These rockets, when they fall upon the troops of an enemy, wound them very dangerously, without their being able to prevent it. The advantage, more particularly derived, is, that they may be projected from under cover, and to double the distance of ordinary musketry. To make use of these rockets, a box is constructed, whose interior is so arranged as to receive the rockets in regular order. They should be placed in it with their sticks; and, therefore, the case must be made sufficiently large to admit them. By this contrivance, the rockets are sheltered from the fire and water. To discharge them, the box is first inclined on the side next to the heads of the rockets, and in the direction of the place, to which they are to be thrown. A communication is made by leaders, in the manner already mentioned in the preceding part of this work; so that, when the match is fired, or a single rocket, they all are discharged at the same time. The mode of firing rockets either singly or in numbers, the manner of preparing the cases, the different compositions, and the operation of filling, and of furnishing them, &c. are given in the preceding part.

Sec. XXVI. Of the Rocket Light-Ball.

Congreve also invented a species of light-ball, which, when thrown into the air by means of one of his rockets, and having reached the elevation of the rockets' ascent, is detached from it with an explosion, and remains suspended in the air by a small parachute, to which it is connected by a chain. Thus, in lieu of the transient momentary gleam, obtained by the common light ball, a permanent and brilliant light is obtained, and suspended in the air for five minutes at least, so as to afford time and light sufficient to observe the motions of an enemy, either on shore or at sea; where it is particularly useful in chasing, and for giving distant and more extensive night signals. It is to be observed, that nothing of this kind can be obtained by the projectile force of either guns or mortars; because the explosion infallibly destroys any construction, that could be made to produce the suspension in the air.

We have seen no account of any experiments, which have been made with it.

Sec. XXVII. Of the Floating Rocket Carcass.

Congreve also applied his rocket, and the parachute, for the purpose of conveying combustible matter to distances far beyond the range of any known projectile force, at the same time that it is cheap, simple, and portable. The floating carcass, like the light-ball, is thrown into the air, attached to a rocket, from which being liberated at its greatest altitude, and suspended to a small parachute, it is driven forward by the wind, and will, in a moderate breeze, afford ranges at least double those of the common carcass. It may, therefore, for naval purposes, be thrown from a blockading squadron, in great quantities, by a fair wind, against any fleet or arsenal, without the smallest risk, or without approaching within range of either guns or mortars. The rocket containing the carcass is no larger than the 32 pounder carcass rocket; and the whole expense, added to the rocket, does not exceed five shillings. Nor are the approaches of the carcass itself necessarily visible by night; as it may be so arranged, as not to inflame, till some time after it has settled. It is evidently, therefore, capable of becoming a harassing weapon, if the account of it be true; and, among large fleets and flotillas, it may do as much injury as any other carcass, by lodging unperceived in the rigging, or lighting on extensive arsenals, in such situations, where other means of annoyance could not be used.

Sec. XXVIII. Observations on Rockets.

The following remarks on the subject of rockets by M. Bigot, (Traité d'Artifice de Guerre, p. 131,) may be interesting to the reader.

Authors, who have written on rockets, are of opinion, that the height of the different kinds of rockets should not be increased on account of their diameter; because, as the diameter increases, the rocket also increases in weight and surface; and if augmented in height in the same ratio, its power of ascension would be feeble. It is from this reasoning, together with practice, that they have determined the height of empty cases. Some have given the proportion of six times their exterior diameter, and others again have made them a third longer than the piercer. There has resulted from this difference of opinion, such an irregularity in the formation of rockets, that artificers or fire-workers were left in uncertainty as to the best mode to be pursued. To avoid, however, this embarrassment, if we consider the diameter of the base of the piercer of any kind of rocket as one-third of the exterior diameter of the case, the small end must be the one-sixth part of it; and the piercer and the cone are of the same diameter, and the surface of the one is equal to the surface of the other. We might conclude, accordingly, that the increase of the height of the case, should be the same with all kinds of rockets. It appears by different authors, that the ancient and modern fire-workers have fixed the dimensions of rockets and their piercers, by various experiments. If we take for granted all the heights of the piercers, or the rockets themselves, we obtain a curve of double or treble reflection, which is very evidently in opposition to the above principles, and of the law which results from them.

Experiments prove, that to make a good rocket of half an inch in diameter, the piercer must be five times and a third of the same diameter; and for a rocket of three inches, the piercer, or broach, as it is sometimes called, is only four times the diameter in height. To determine, however, the height of the piercer in general, greater than the preceding, it is found necessary to have some satisfactory result, in order to employ, mathematically speaking, less times of the exterior diameter of the rocket. The half-inch and three-inch rocket are the extremes of an increasing arithmetical progression; and their equivalents, 5¹/₃ and 4 diameters is the extreme of a similar, but decreasing progress; but if we insert the same number of arithmetical mean between the two extremes of each of these two progressions, and then continue them indifferently, the terms of the first will express the diameter of as many different cases; and those of the second, the height of the corresponding piercers. They will be, for instance, in the two following proportions:

The first of which has unity for its common difference. It has been found, that, by inserting in each, a mean of 29, the height of the piercers will correspond with the superior diameter, which is less, or regulated by their respective diameters. Besides, as the diameters go on augmenting, the rockets are proportionably increased in height, but only in an inverse order, until the 58th term included, and beyond which they decrease, until they become negative, which appears to indicate that the term appertains to the diameter of the rocket, and without any uncertainty.

It results from the intimate relation of these two progressions, that, in stopping at the 58th term, if we bring back on an axis as it were, the height of the piercers, we obtain a straight instead of a curved line.

Bigot has given two tables relative to the construction of rockets, and, as their use is seen by mere inspection, we here introduce them without remark.

They comprehend the dimensions of rockets of different calibers, compared with the exterior and respective diameter of each kind; and relative to the dimensions of the tools of sky-rockets of different calibers, and also compared with the exterior and respective diameter of each.

It will be seen, on an examination of these tables, that all the data are satisfactorily given; so that, in the construction of rockets, the artificer will find them extremely useful, if not absolutely necessary.

The principles on which these tables are founded, may be depended on, inasmuch as M. Bigot has taken considerable pains on that head; and, consequently, the calculations, which follow, and the proportions, established for the construction of rockets in general, are sufficiently conclusive.