business of a gun-smith, or the art of making fire-arms of the smaller sort, as muskets, fowling-pieces, pistols, &c.

The principal part of these instruments is the barrel, which ought to have the following properties. 1. Lightness, that it may incommode the person who carries it as little as possible. 2. Sufficient strength and other properties requisite to prevent its bursting by a discharge. 3. It ought to be constructed in such a manner as not to recoil with violence. And, 4. It ought to be of sufficient length to carry the shot to as great a distance as the force of the powder employed is capable of doing.

The manufacture of fire-arms is now carried to such a degree of perfection by different European nations, that it may perhaps be justly doubted whether any farther improvement in the requisites just mentioned can be made. For the materials, the softest iron that can be procured is to be made use of. The best in this country are formed of stubs, as they are called, or old horse-shoe nails; which are procured by the gun-smiths from farriers, and from poor people who subsist by picking them up on the great roads leading to London. These are sold at about 10s. per cwt. and 28 pounds are requisite to form a single musket barrel. The method of manufacturing them from this material is as follows: A hoop of about an inch broad, and six or seven inches diameter, is placed in a perpendicular situation, and the stubs, previously well cleaned, piled up in it with their heads outwards on each side, till the hoop is quite filled and wedged tight with them. The whole then resembles a rough circular cake of iron; which being heated to a white heat, and then strongly hammered, coalesces into one solid lump. The hoop is now removed, and the beatings and hammerings repeated till the iron is rendered very tough and close in the grain; when it is drawn out into pieces of about 24 inches in length, half an inch or more in breadth, and half an inch in thickness.

Four of these pieces are employed for one barrel; but in the ordinary way a single bar of the best soft iron is employed. The workmen begin with hammering out this into the form of a flat ruler, having its length... length and breadth proportioned to the dimensions of the intended barrel. By repeated heating and hammering this plate is turned round a tempered iron rod called a mandril, the diameter of which is considerably smaller than the intended bore of the barrel. One of the edges of the plate being laid over the other about half an inch, the whole is heated and welded by two or three inches at a time, hammering it briskly, but with moderate strokes, upon an anvil which has a number of semicircular furrows in it, adapted to barrels of different sizes. Every time the barrel is withdrawn from the fire, the workman strikes it gently against the anvil once or twice in an horizontal direction. By this operation the particles of the metal are more perfectly consolidated, and every appearance of a seam in the barrel is obliterated. The mandril being then again introduced into the cavity of the barrel, the latter is very strongly hammered upon it in one of the semicircular hollows of the anvil, by small portions at a time; the heatings and hammerings being repeated until the whole barrel has undergone the operation, and its parts rendered as perfectly continuous as if they had been formed out of a solid piece. To effect this completely, three welding heats are necessary when the very best iron is made use of, and a greater number for the coarser kinds. The French workmen imagine, that by giving the barrel, while in the fire, slight horizontal strokes with the hammer, so as to communicate a vibratory motion to the iron, those particles are thrown off which are in a state of fusion and cannot easily be converted into malleable iron: but considering the great number of operations already described which the metal has undergone, we can scarce suppose this to be of much consequence.

The next operation in forming the barrels is the boring of them, which is done in the following manner: Two beams of oak, each about six inches in diameter, and six or seven feet long, are placed horizontally and parallel to one another; having each of their extremities mortised upon a strong upright piece about three feet high, and firmly fixed. A space of three or four inches is left between the horizontal pieces, in which a piece of wood is made to slide by having at either end a tenon let into a groove which runs on the inside of each beam throughout its whole length. Through this sliding piece a strong pin or bolt of iron is driven or screwed in a perpendicular direction, having at its upper end a round hole large enough to admit the breach of the barrel, which is secured in it by means of a piece of iron that serves as a wedge, and a vertical screw passing through the upper part of the hole. A chain is fastened to a staple in one side of the sliding piece which runs between the two horizontal beams; and passing over a pulley at one end of the machine, has a weight hooked on to it. An upright piece of timber is fixed above this pulley and between the ends of the beams, having its upper end perforated by the axis of an iron crank furnished with a square socket; the other axis being supported by the wall, or by a strong post, and loaded with a heavy wheel of cast iron to give it force. The axes of this crank are in a line with the hole in the bolt already mentioned.—The borer being then fixed into the socket of the crank, has its other end, previously well oiled, introduced into the barrel, whose breech part is made fast in the hole of the bolt: the chain is then carried over the pulley, and the weight hooked on; the crank being then turned with the hand, the barrel advances as the borer cuts its way, till it has passed through the whole length.—The boring bit consists of an iron rod somewhat longer than the barrel, one end of which fits the socket of the crank; the other is adapted to a cylindrical piece of tempered steel about an inch and a half in length, having its surface cut after the manner of a perpetual screw, with five or six threads, the obliquity of which is very small. The breadth of the furrows is the same with that of the threads, and their depth sufficient to let the metal cut by the threads pass through them easily. Thus the bit gets a very strong hold of the metal; and the threads, being sharp at the edges, scoop out and remove all the inequalities and roughnesses from the inside of the barrel, and render the cavity smooth and equal throughout. A number of bits, each a little larger than the former, are afterwards successively passed through the barrel in the same way, until the bore has acquired the magnitude intended. By this operation the barrel is very much heated, especially the first time the borer is passed through it, by which means it is apt to warp. To prevent this in some measure, the barrel is covered with a cloth kept constantly wetted, which not only preserves the barrel from an excess of heat, but likewise preserves the temper of the bit from being destroyed. The borer itself must also be withdrawn from time to time; both to clean it from the shavings of the metal and to oil it, or repair any damages it may have sustained. Every time a fresh bit has been passed through the barrel, the latter must be carefully examined, to see if it has warped; and, likewise if there are any spots, by the workmen called blacks, on its inside. When warped, it must be straightened on the anvil; for which a few light strokes on the convex parts will be sufficient; and this is termed setting up the barrel. When black spots are perceived, the corresponding part on the outside must be marked, and driven in by gentle strokes with the hammer, when they will be completely removed by passing the borer another time through the piece.

The equality of the bore is of the utmost consequence to the perfection of a barrel; inasmuch that the greatest possible accuracy in every other respect will not make amends for any deficiency in this respect. The method used by gunsmiths to ascertain this is by a cylindrical plug of tempered steel highly polished, about an inch in length, and fitting the bore exactly. This is screwed upon the end of an iron rod, and introduced into the cavity of the barrel, where it is moved backwards and forwards; and the places where it passes with difficulty being marked, the boring bit is repeatedly passed until it moves with equal ease through every part. Any person who wishes to know the merit of his piece in this respect, may do it with tolerable accuracy by means of a plug of lead cast on a rod of iron; or even by a musket ball filed exactly to the bore, and pushed through the barrel by a ramrod; taking care, however, not to use much force lest the ball be flattened, and its passage thus rendered difficult.

The last step towards the perfection of the inside of the barrel is termed fine-boring; by which is meant the smoothing it in such a manner as to remove all marks and inequalities left by the borer. The fine borer resembles GUN

femblies the other in its general construction; but instead of the piece of steel cut in form of a screw which belongs to that, it is furnished with a square broach 10 or 12 inches long, highly polished, and very sharp, by which means it cuts the metal very smoothly. It is found to answer the purpose best when only two of its edges are allowed to work; the other two are covered with slips of oiled paper, one or more additional slips being put on each time that the instrument is passed through the barrel. The fine-borer is frequently passed through, from the muzzle to the breech, and from the breech to the muzzle, until the whole inside presents a perfectly equal and polished surface; the barrel being likewise examined and set up, if requisite, after each time. It is absolutely necessary that this instrument should be perfectly true, and not in the least calf or warped in the tempering.

Besides the operations above described, another, called 'polishing,' is usually performed on gun-barrels, though it is doubtful whether this last be attended with any good effect or not. It is performed by a cylinder of lead, five or six inches long, cast upon a road of iron, and filed exactly to the bore. The lead being then covered with very fine emery and oil, is wrought backwards and forwards through the whole length of the barrel until the inside has acquired the requisite degree of polish. The disadvantages of this operation are, that it is scarce possible to perform it without pressing more upon one part than another, and thus producing some degree of inequality on the inside, which is of the very worst consequence to fire-arms. The polish thus given is likewise very perishable; so that the fine-boring may justly be considered as the last operation necessary for the inside of a barrel; and it is then proper to give the external form and proportions by means of a file. For this purpose, four faces are first formed upon it, then eight, then 16; and so on till it be quite round, excepting the part next the breech, called the reinforced part, which is always left of an octagonal form. It being absolutely necessary that the barrel should be equally thick on every side, gunsmiths employ, for accomplishing this purpose, a particular tool named a compass. This consists of an iron rod bent in such a manner as to form two parallel branches about an inch distant from one another. One of these branches is introduced into the barrel, and kept closely applied to the side, by means of one or more springs with which it is furnished; the other descends parallel to this on the outside, and has several screws passing through it with their points directed to the barrel. By screwing these until their points touch the surface of the barrel, and then turning the instrument round within the bore, we perceive where the metal is too thick, and how much it must be reduced, in order to render every part perfectly equal throughout its circumference. It may be made long enough to reach the whole length of the barrel, though it will be more convenient to have it only half as much, and to introduce it first at one end and then at the other. Instead of rounding the barrel by means of a file and compass, however, some people do so by turning it in a lathe; which is no doubt more expeditions, though neither so certain nor exact. A spindle as long as a gun-barrel cannot, without great difficulty, be prevented from springing considerably under the tool employed to reduce or smooth it in turn-

GUN

are more frequently warped than by all the borings they undergo; and there is now this farther inconvenience, that they cannot be set up as formerly, without danger of destroying them entirely.

The barrels being thus bored and formed externally, it is customary with the gunsmiths in France to folder on the loops and aim before they breach the barrel. The English, however, do not restrict themselves in this manner; for as soft folder is sufficient for fastening on these, they never use any other; while the French, who use hard folder, must of consequence employ a great heat. Thus the inside is roughened sometimes to considerably, that it is necessary to repeat the fine boring; which could not be done without injuring the threads of the screw formed for the breech, if the barrel were prepared for the latter without foldering on the former.

The first tool employed in forming the breech-screw is a plug of tempered steel, somewhat conical, with the threads of a male screw upon its surface, and by the workman termed a screw tip. This being introduced into the barrel, and worked from left to right and back again, until it has marked out the four first threads of the screw, another less conical tap is introduced; and when this has carried the impression of the screw as far as it is intended to go, a third one, nearly cylindrical, is made use of, scarcely differing from the plug of the breech intended to fill the screw thus formed in the barrel. The plug itself has its screw formed by means of a screw-plate of tempered steel, with several female screws, corresponding with the taps employed for forming that in the barrel. Seven or eight threads are a sufficient length for a plug; they ought to be neat and sharp, so as completely to fill the turns made in the barrel by the tap. The breech-plug is then to be case-hardened, or to have its surface converted into steel, by covering it with shavings of horn, or the parings of the hoofs of horses, and keeping it for some time red hot; after which it is plunged in cold water.

The only thing now requisite for completing the barrels is to give them a proper colour; as a preparation for which their outside is first to be neatly polished with oil and emery. This being done, it was formerly the custom to give such a degree of heat as would make them blue throughout; but as this cannot be effected without a partial calcination of the surface, which of consequence affects the inside also, the blue colour has been for some time disused, and a brown one substituted in its place. To give this colour, the pieces are first rubbed over with aquafortis or spirit of salt diluted with water; after which they are laid by till a complete coat of rust is formed upon them; a little oil is then applied; and the surface being rubbed dry, is polished by means of a hard brush and bees-wax.

Thus the common musket-barrels for the purposes especially of sportsmanship are made; but there are some other methods of manufacture, by which the barrels are made to differ in some respects from those just described, and are thought to be considerably improved. One kind of these are called twisted barrels; and by the English workmen are formed out of the plates made of flubs formerly described. Four of these, of the size already mentioned, are requisite to make one barrel. One of them heated red hot for five or six inches is turned... turned like a cork-screw by means of the hammer and anvil; the remaining parts being treated successively in the same manner until the whole is turned into a spiral, forming a tube the diameter of which corresponds with the bore of the intended barrel. Four are generally sufficient to form a barrel of the ordinary length, i.e., from 32 to 38 inches; and the two which form the breech or strongest part, called the reinforced part, are considerably thicker than those which form the muzzle or fore part of the barrel. One of these tubes is then welded to a part of an old barrel to serve as a handle; after which the turns of the spiral are united by heating the tube two or three inches at a time to a bright white heat, and striking the end of it several times against the anvil in a horizontal direction with considerable strength, which is called jumping the barrel; and the heats given for this purpose are called jumping heats. The next step is to introduce a mandril into the cavity, and to hammer the heated portion lightly in order to flatten the ridges or burrs raised by the jumping at the place where the spirals are joined. As soon as one piece is jumped throughout its whole length, another is welded to it, and treated in the same manner, until the four pieces are united, when the part of the old barrel is cut off, as being no longer of any use. The welding is repeated three times at least, and is performed exactly in the same manner as directed for plain barrels; and the piece may afterwards be finished according to the directions already given.

The operation for the French twisted barrels is very different from that just mentioned, and much more exceptional. It consists in heating the barrel by a few inches at a time to a strong red heat; one end is then screwed into a vice, and a square piece of iron with a handle like an auger is introduced into the other. By means of these the fibres of the heated portion are twisted into a spiral direction, which is supposed to resist the effort of the inflamed powder better than the other. To render this operation complete, however, it must be observed, that when once the several portions of the barrel have been twisted, the subsequent heats ought not to be very great, or the grain of the metal will regain its former state, and the barrel be no better for the twisting than before. To twist a barrel in this manner, also, it will be necessary to forge it at least half a foot longer than it is intended to be, that a sufficient length may be kept cold at each end to give a sufficient purchase to the vice and twisting instrument; and these portions must afterwards be cut off before the barrel is bored, or two pieces of an old barrel may be welded to the muzzle and breech of that which is to be twisted, and cut off when the operation is over. These pieces may also be made stronger than usual to resist the force of the vice and twisting instrument; and in order to give the latter a firmer hold, the cavity of the muzzle may be made of a square form. The English workmen are unanimously of opinion that this method of twisting is really injurious to the barrel, by straining the fibres of the metal. At any rate, from the injudicious methods followed by the French artists, the greatest part of their barrels, said to be twisted, are not so in reality; there being at least six or seven inches at the muzzle, and seven or eight at the breech, which are not affected by the operation.

The French ribbon barrels have a great resemblance to the English twisted ones; but the process for making them is much more operose, though it seems not to possess any real advantage over that used by the English artists. A plate of iron, about the twelfth part of an inch in thickness, is turned round a mandril, and welded its whole length in the same manner as a plain barrel. Upon this flight barrel, which is called the lining, a plate of iron about an inch in breadth, and bevelled off at the edges, is by means of successive heats rolled in a spiral direction; after which it is termed the ribbon, and must have a thickness corresponding with that part of the barrel which it is to form. As it would, however, be difficult to form a ribbon of sufficient length for the whole barrel, it is made in several pieces; and when one piece is rolled on, another is welded to its end, and the operation continued until the lining be entirely covered. The edges are so much bevelled, that the one folds over the other about a quarter of an inch. After the ribbon is all rolled on, the barrel must be heated by two or three inches at a time, and the turns of the spiral united to each other and to the lining by being welded in the same manner as the twisted barrel; though, from what has been said of the construction of these barrels, it is plain that the operation of jumping cannot be admitted in them. The barrel is afterwards bored in such a manner that almost the whole of the lining is cut out, and scarce anything left but the ribbon with which the lining was covered.

The superiority of twisted and ribbon barrels over the plain kind gave occasion to a third sort named wired barrels. These were invented by an ingenious workman at Paris named Barrois; whose method was as follows: Upon a thin barrel, filed and dressed as usual, he rolled, as close as possible, and in a spiral direction, a tempered iron wire about the thickness of a crow-quill, the first layer covering only the reinforced part. The turns of the wire were soldered to each other and to the barrel with a composition which he kept a secret. The wired part was then filed smooth and bright, but not so much as to weaken it; a second layer of wire was applied over the first, extending two-thirds of the length of the barrel; and this being smoothed and brightened like the first, a third layer was applied, which covered the two former and reached quite to the muzzle.

The barrels made after this manner are supposed to be much superior to others, though the supposition seems not to be well founded. It is certain that wire is not preferable to other iron as a material for gun-barrels; and the folder used by M. Barrois in a quantity nearly equal to the wire itself, must be accounted a defect as far as it was used; for no metal has yet been found equal to iron for the purposes of gunsmiths: so that by the use of so much of this folder in the composition of the barrel, it must be undoubtedly weaker than if it had been all made of iron. We are not to suppose the wire absolutely free from flaws; and even though it were, there will always be small cavities between its turns, which the folder cannot fill completely. Besides, as the operation of wiring was performed by M. Barrois upon a barrel that had been previously bored and dressed within, the repeated heats to which it was afterwards subjected in soldering, if they did not cause it warp, at least rendered it so rough. The only advantage therefore which these barrels were found to possess was their beautiful appearance; which was greatly overbalanced by the circumstances just mentioned, as well as by the extravagant prices at which they were sold; a single barrel being sold at £1, and a double one at twice that sum; whence the sale of them never answered the expectation of the inventor, and after his death no body thought of making them.

The Spanish barrels have long been held in great estimation, both on account of their being formed of better iron than those of other countries, and likewise from an opinion of their being more perfectly forged and bored. Those made at Madrid are the best, and even of these such as have been made by former gunsmiths are in the greatest estimation. The most celebrated Spanish gunsmiths were Nicolas Biz, who lived in the beginning of the present century, and died in 1724; and the barrels fabricated by him in the former part of his life are held in greatest estimation. Those of his contemporaries, Juan Belan and Juan Fernandez, are no less valued; all of their barrels selling in France at 1000 livres, or £45.15s. sterling. The successors of these great artists were Diego Esquibal, Alonzo Martinez, Agustin Ortiz, Matthias Vacra, Luis Santos, Juan Santos, Francisco Garcia, Francisco Targarone, Joseph Cano, and N. Zelaya. The most celebrated now in life are Francisco Loper, Salvador Cenarro, Miguel Zeguerra, Ilidoro Soler, and Juan de Soto. The three first are gunsmiths to the king; and the barrels made by all of them sell for £31. sterling. Almost all the Madrid barrels are composed of the old shoes of horses and mules, which are collected for the purpose. They are manufactured first by welding longitudinally, and then being joined together in four or five pieces like the English barrels made from stubs, as already mentioned. In this, and indeed all other operations for making gun-barrels, an immense waste of the iron takes place; but that of the Spanish iron is by far the greatest, a mass of 40 or 45 pounds being required to make one barrel, which when rough from the forge weighs only six or seven pounds; so that from 30 to 38 pounds are lost in the hammerings. It may perhaps, however, be doubted, whether the iron be really purified by this waste; for it is certain, that by long continued working in the fire it may be rendered totally useless and destroyed; neither can we be assured that the other advantages pretended to result from their method of manufacture are of any consequence. The Spanish artists likewise value themselves on giving the inside of their barrels a very high polish; but the advantage of this, as has already been observed, is extremely dubious. The only thing requisite in a gun-barrel is that it do not lead; that is, that the mark of the bullet be not perceived on the inside after it has been discharged, by some of the lead rubbed off as it passes through. In the opinion of very good judges, therefore, it is better to take a barrel immediately after it has undergone the operation of fine-boring than to give it any higher polish; and in support of this opinion, M. de Marolles, an author of great reputation, informs us, that he has seen a barrel rough from the borer throw a charge of shot deeper into a quire of paper than one which was highly polished within, though the length, bore, and charge, were the same in both.

As the Spanish iron is universally allowed to be excellent, it has not been unreasonably supposed that the superiority of the barrels manufactured in that kingdom is owing more to the goodness of the materials than to the skill of the workmen. It must be observed, however, that instead of making the plates overlap a little in the place where they join, they give one of them a complete turn; so that every Spanish barrel may be said to be double throughout its whole length. The different portions of the iron are also forged in such a manner, that the grain of the iron is disposed in a spiral manner; whence it has the same effect with a ribbon or twisted barrel. The outside is finished by turning them in a lathe; whence probably they are always less elegantly wrought than the French and English pieces. The great value put upon them is also thought to be more owing to fancy than to any real good qualities they possess. Formerly they were made from three to three feet and a half long; their bore being such as to admit a bullet from 22 to 24 inches in diameter; and their weight from three to three pounds and a half. The reinforced part extends two-fifths of the length; and at 10 or 12 inches from the breech is placed a sight, such as is usually put upon rifle-barrels or those intended only for ball. According to Espinas, arquebus-bearer to Philip IV., the weight of a Spanish barrel ought to be four pounds and a half when their length is 42 inches; but both weight and length are now much reduced, they seldom exceeding the dimension already mentioned. Next to the barrels made at Madrid, the most esteemed are those of Buttingui and St Olabe at Placentia in Biscay; and of Jean and Clement Padwetteva, Eudal Pous, and Martin Marechal, at Barcelona; the usual price of them being about £1.10s. sterling.

Having now described the method of forging barrels, we shall next proceed to give an account of those imperfections to which they are sometimes liable, and which render them apt to burst or recoil with violence. The principal of these are the chink, crack, and flaw. The first is a small rent in the direction of the length of the barrel; the second across it; and the third is a kind of scale or small plate adhering to the barrel by a narrow base, from which it spreads out like the head of a nail from its shank; and when separated leaves a pit or hollow in the metal. The chink or flaw are of much worse consequence than the crack in fire-arms, the force of the powder being exerted more upon the circumference than the length of the barrel. The flaw is much more frequent than the chink, the latter scarcely ever occurring but in plain barrels formed out of a single plate of iron, and then only when the metal is deficient in quality. When flaws happen on the outside, they are of no great consequence; but in the inside they are apt to lodge moisture and foulness which corrode the iron, and thus the cavity enlarges continually till the piece bursts. This accident, however, may arise from many other causes besides the defect of the barrel itself. The best pieces will burst when the ball is not sufficiently rammed home, so that a space is left between it and the powder. A very small windage or passage for the inflamed powder between the sides of the barrel and ball will be sufficient to prevent the... the accident; but if the ball has been forcibly driven down with an iron ramrod, so as to fill up the cavity of the barrel very exactly, the piece will almost certainly burst, if only a very small space be left between it and the powder; and the greater the space is, the more certainly does the event take place. Of this Mr Robins gives a remarkable instance, accounting at the same time for the phenomenon. "A moderate charge of powder (says he), when it has expanded itself through the vacant space and reaches the ball, will, by the velocity each part has acquired, accumulate itself behind the ball, and will thereby be condensed prodigiously: whence, if the barrel be not of an extraordinary strength in that part, it must infallibly burst. The truth of this I have experienced in a very good Tower musket, forged of very tough iron: for charging it with 12 pennyweight of powder, and placing the ball loosely 16 inches from the breech; on the firing of it, the part of the barrel just behind the bullet was swelled out to double its diameter like a blown bladder, and two large pieces of two inches in length were burst out of it." A piece will frequently burst from having its mouth flopped up with earth or snow; which accident sometimes happens to sportsmen in leaping a ditch, in which they have affixed themselves with their fowling-piece, putting the mouth of it to the ground; and when this does not happen, it is only to be accounted for from the stoppage being extremely tight. For the same reason a musket will certainly burst if it be fired with the muzzle immersed only a very little way in water. It will also burst from an overcharge; but when such an accident happens in other circumstances, it is most probably to be attributed to a defect in the workmanship, or in the iron itself. These defects are principally an imperfection in the welding, a deep flaw having taken place, or an inequality in the bore; which last is the most common of any, especially in the low-priced barrels. The reason of a barrel's bursting from an inequality in the bore is, that the elastic fluid, set loose by the inflammation of the powder, and endeavouring to expand itself in every direction, being repelled by the stronger parts, acts with additional force against the weaker ones, and frequently bursts through them, which it would not have done had the sides been equally thick and strong throughout. With regard to defects arising from the bad quality of the iron, it is impossible to say anything certain. As the choice of the materials depends entirely on the gunsmith, the only way to be assured of having a barrel made of proper metal is to purchase it from an artist of known reputation, and to give a considerable price for the piece.

The recoil of a piece becomes an object of importance only when it is very great; for every piece recoils in some degree when it is discharged. The most frequent cause of an excessive recoil is an inequality in the bore of the barrel; and by this it will be occasioned even when the inequality is too small to be perceived by the eye. The explanation of this upon mechanical principles indeed is not very easy: for as it is there an inevitable law, that action and reaction are equal to one another, we should be apt to suppose that every time a piece is discharged it should recoil with the whole difference between the velocity of the bullet and that of the inflamed powder. But were this the case, no man could fire a musket without being destroyed; for the bullet flies out only with a velocity of 1700 feet in a second, or not much more, while that of the powder, as calculated by Mr Robins, is not less than 7000 feet in the same space. But was the recoil to be made with the difference of these velocities, or with one half of it, it is plain that no man could bear it. The same thing therefore must take place in the recoil of a musket which Dr Priestley observed in his experiments on the explosion of inflammable and dephlogisticated air, viz. that the force is exerted much more upon the part farther from that where the inflammation begins than upon that next to it. At any rate, however, the strength of the recoil will always be found proportionate to the weight of the piece; that is, the lighter the piece is, the greater the recoil, and vice versa. The recoil may be increased by any thing which retards the passage of the shot; whence it is also augmented by the fouling of the barrel by repeated firing. M. de Marolles informs us also, that a piece will recoil, if from the breech-plug being made too short, some turns of the screw remain empty; as in these a part of the powder is lodged which forms an obstacle to the explosion; though in what manner this takes place is not very apparent, as though the powder lodged there might contribute little or nothing to the force of the explosion, it can scarce be shown to stand in the way of it. The same author likewise informs us, that a barrel mounted upon a very straight stock will recoil more than upon one that is considerably bent. Sometimes also a fowling-piece will recoil from the sportsman applying it improperly to his shoulder; though this last circumstance seems likewise inexplicable. It is most probable therefore that the supposed greater recoil taken notice of in this case, arises only from the usual recoil being more sensibly felt in one position than another.

The cause to which too great a recoil in muskets has been usually attributed, is the placing of the touch-hole at some distance from the breech plug; so that the powder is fired about the middle, or towards its fore-part, rather than at its base. To avoid this, some artists form a groove or channel in the breech plug as deep as the second or third turn of the screw; the touch-hole opening into this channel, and thus firing the powder at its very lowest part. It appears, however, from a number of experiments made upon this subject by M. le Clez gunsmith to the king of France, that it made very little difference with regard to the recoil, whether the touch-hole was close to the breech or an inch distant from it. The only circumstance to be attended to with respect to its situation therefore is, that it be not quite close to the breech plug; as in such a case it is found to be more apt to be choked up than when placed about a quarter of an inch from it.

The only other circumstance now to be determined with regard to musket-barrels is their proper length. Formerly it was supposed that the longer they were made, the greater would be the distance to which they carried the shot, and that without any limitation. This opinion continued to prevail till about half a century ago, when it was first proposed as a doubt whether long barrels carried farther than short ones. With regard to cannon, indeed, it had long before this time been been known that they might be made too long; and Balthazar Killar, a celebrated cannon-founder in the reign of Louis XIV., was able to account for it. When asked by Mons. Surily de St Remy, why the culverin of Nancy, which is 22 feet long, did not carry a ball equally far with a shorter piece? he replied, that "the powder, when inflamed, ought to quit the cavity of the piece in a certain time, in order to exert its whole force upon the bullet: by a longer stay, part of the force is lost; and the same cause may produce an inequality in the shots, by giving a variation to the bullet, so as to destroy its rectilinear course, and throw it to one side or other of the mark." Mr. Robins, who on this as well as every other question in gunnery has almost exhausted the subject, informs us, that "if a musket-barrel, of the common length and bore, be fired with a leaden bullet and half its weight of powder, and if the same barrel be afterwards shortened one half and fired with the same charge, the velocity of the bullet in this shortened barrel will be about one-sixth less than what it was when the barrel was entire; and if, instead of shortening the barrel, it be increased to twice its usual length, when it will be near eight feet long, the velocity of the bullet will not hereby be augmented more than one-eighth part. And the greater the length of the barrel is in proportion to the diameter of the bullet, and the smaller the quantity of powder, the more unconsiderable will these alterations of velocity be." From these considerations it appears, that the advantages gained by long barrels are by no means equivalent to the disadvantages arising from the weight and incumbrance of using them; and from a multitude of experiments it is now apparent, that every one may choose what length he pleases, without any sensible detriment to the range of his piece. The most approved lengths are from 32 to 38 inches.

An opinion has generally prevailed among sportsmen, that by some unknown manoeuvre the gunsmith is able to make a piece, loaded with small shot, throw the contents so close together, that even at the distance of 40 or 50 paces the whole will be confined within the breadth of a hat. From such experiments as have been made on this subject, however, it appears, that the closeness or wideness with which a piece throws its shot is liable to innumerable variations from causes which no skill in the gunsmith can possibly reach. So variable are these causes, that there is no possibility of making the same piece throw its shot equally close twice successively. In general, however, the closer the wadding is, the better disposed the shot seems to be to fall within a small compass. The closeness of the shot therefore would seem to depend in a great measure on preventing the flame of the powder from infusing itself among its particles: whence the following method is said to be practised with success by those who shoot for a wager at a mark with small shot; viz. to put in the shot by small quantities at a time, ramming down a little tow or thin paper over each; so as to fill the interstices of the grains, and thus prevent the flame from getting in amongst the grains and scattering them. In firing with small shot, a curious circumstance sometimes occurs, viz. that the grains, instead of being equally distributed over the space they strike, are thrown in clumps of 10, 12, 15, or more; whilst several considerable spaces are left without a grain in them. Sometimes one-third or one half of the charge will be collected into a cluster of this kind; nay, sometimes, though much more rarely, the whole charge will be collected into one mass, so as to pierce a board near an inch thick at the distance of 40 or 45 paces. Small barrels are said to be more liable to this clustering than large ones; and M. de Marolles informs us, that this is especially the case when the barrels are new, and likewise when they are fresh-washed; though he acknowledges that it did not always happen with the barrels he employed even after they were washed. It is probable, therefore, that the closeness of the shot depends on some circumstance relative to the wadding rather than to the mechanism of the barrel.

Some pieces are composed of two or more barrels joined together; in which case the thickness of each of the barrels is somewhat less than in single-barrelled pieces. After being properly dressed, each of them is filed flat on the side where they are to join each other, so that they may fit more closely together. Two corresponding notches are then made at the muzzle and breech of each barrel; and into these are fitted two small pieces of iron to hold them more strongly together. Being then united by tinning the contiguous parts, a triangular piece of iron called the rib is fastened on in like manner, running the whole length on the upper side; which serves to hold them more strongly together. After this they are to be polished and coloured in the manner described for single barrels. Great care should be taken that the barrels joined in this manner should be quite equal in strength to one another, and that both should be quite upright, or of an equal thickness throughout. If any inequality takes place in the strength of the barrels, the weaker will be warped by the action of the stronger; and the warping from this cause has sometimes been so considerable as to render one of the barrels useless. To bring every part of the circumference of each barrel to an equal strength as nearly as possible, so that no part may be strained by the explosion, that side where they touch each other must be so reduced, that the partition between the two calibers may be no thicker than either barrel was at the same place before it was filed to join in this manner. Formerly the double-barrelled pieces were made with one barrel lying over the other, each barrel having a separate pan, hammer, and hammer-spring, but only one cock for both. The barrels were therefore made to turn round at the place where the breeches joined with the flock; so that as soon as one was fired off, the other could be brought into its place by pressing a spring moved by the guard with the right hand, while with the left the barrels were turned upon their common axis; and as soon as the charged barrel was thus brought into its proper situation, the spring descended into a notch and kept it firm. But this method was found to be too complicated and embarrassed, though upon the same plan three and four barrels were sometimes mounted upon one flock; but these pieces were intolerably heavy, and have no real superiority over the double-barrelled pieces which do not turn round, and which of consequence are now only made use of.

In forging barrels of all kinds, it is of considerable importance to have them made at first as near as possible ble to the weight intended when they are finished, so that very little be taken away by the boring and filing: for as the outer surface, by having undergone the action of the hammer more immediately than any other part, is rendered the most compact and pure, we should be careful to remove as little of it as possible; and the same holds, though in a less degree, with the inside, which is to be cut with the borer. Pistol-barrels are forged in one piece, two at a time, joined by their muzzles, and are bored before they are cut astern; by which means there is not only a saving of time and labour, but a greater certainty of the bore being the same in both.