From these experiments it appears, that, with regard to the recoil, the distance of the touchhole from the breech is of little importance. The only circumstance, therefore, to be attended to in its situation, is, that it be not placed quite close to the breech-plug; for, although that part of the barrel where the powder is lodged, dirties much less than a few inches farther forward, yet the touch-hole, when close to the breech-plug, is found to be more frequently stopped up than when situated about a quarter of an inch from it. Of the range of barrels.-The lightness of fowl ing pieces of a moderate length, and the ease with which they are managed, are advantages so obvious, and at the same time so considerable, as to give them a general preference at this time; but, as the circumstances upon which only this preference ought to be rested are little known, it is not sufficient that their use is general, and daily increasing, unless it be determined what are the comparative excellencies and defects of long and short barrels, and it be thence shewn whether sportsmen sacrifice one advantage to gain another. The generally-received opinion upon this subject is, that to obtain an increase in the range, the barrel must not only be made longer than usual, but that the length and the diameter of the bore ought to bear a certain proportion to each other, and the charge of powder be suited to this proportion; because, as it is said, when the barrel is too short, the ball of shot quits it before it has received the whole impulse of the powder; and, on the other hand, when the barrel is too long, that the powder is not only all inflamed, but even partly consumed, before the ball or shot arrives at the mouth of the piece. The elastic fluid produced by the firing of gunpowder is found, by experiment, to occupy, when cooled to the temperature of the atmosphere, a space two hundred and forty-four times greater than that taken up by the powder from which it was obtained. But from the heat generated during the explosion, this elastic fluid is rarefied to upwards of four times its former bulk. The expansive force of this fluid, therefore, is, at the moment of inflammation, one thousand times greater than that of common air, or, which is the same, than the pressure of the atmosphere; or, supposing the powder to have occupied the space. of one cubic inch, its expansive force, when fired, is equal to that which would be exerted by one thousand cubic inches of common air compressed into the space of one inch. As the velocity with which the flame of gunpowder expands when uncompressed is much greater than that with which the ball, or shot, moves forward, the flame must continue to press upon the ball, and adds to its velocity, until it quits the mouth of the piece. This pressure, however, becomes less and less, as the ball proceeds, and ceases entirely when it leaves the muzzle, in consequence of the flame being then allowed to expand itself laterally. Thus, for example, if the charge of powder takes up one inch of the barrel, and the whole length of the barrel be thirty inches, then, when the ball arrives at the muzzle of the piece, the inflamed powder (whose expansive effort is in proportion to the smallness of the space it occupies) extends through thirty times the space it did when the ball began to move, and consequently presses forward with but one-thirtieth part the force it possessed at first. Moreover, although the velocity of the bullet is continually increased by this pres VOL. V. sure of the inflamed powder, its acceleration be comes less and less as it proceeds through the barrel; for, besides that the quantity of the pressure diminishes as the flame expands, the bullet, continuing to move faster and faster, must receive continually less and less addition of impulse from the flame pressing behind it. Hence, if two pieces of the same bore, but of different lengths, are charged with the same quantity of powder, the longer piece will, strictly speaking, communicate the greater velocity and force to its ball, or shot. shown to be nearly instantaneous, and as the inBut as the inflammation of the powder has been crease of acceleration, which the ball or shot receives after the first impulse of the powder upon with which two barrels of the same bore, and with it, is not very considerable, it follows that the force the same charge, throw the ball or shot, will be nearly the same, unless their lengths be extremely disproportionate. To prove this, we shall quote what is said by that able mathematician and engineer, the late Mr. Benjamin Robins, to whose work we are indebted for much valuable information. "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 inconsiderable will these alterations of velocity be." When the allowance which Mr. Robins here takes notice of are made in the proportion required for fowling-pieces, the result will be found to correspond exactly with the experiments which we have repeatedly made, with every possible atten. tion to accuracy. We have, at different times, compared barrels of all the intermediate lengths between twenty-eight and forty inches, and of nearly the same caliber; and these trials were made both by firing the piece from the shoulder, and from a firm block, at an equal distance, and with equal weights of the same powder and of the same shot. To avoid every possibility of error, the quires of paper at which we fired were fixed against planks, instead of being placed against a wall. From these trials, frequently repeated, we found that the shot pierced an equal number of sheets, whether it was fired from a barrel of 28, 30, 32, 34, 36, 38, or 40 inches in length. Nay more, we have compared two barrels of the same caliber, but one of them thirty-three and the other thirty-six inches long, by repeatedly firing them, in the same manner as the others, at different distances from forty-five to one hundred paces, and the results have always been the same, i. e. the barrel of thirty-three inches drove its shot through as many sheets of paper as that of sixty-six did. The conclusion from all this is, that the difference of ten inches in the length of the barrel, which seems to be more than is ever insisted upon among sportsmen, produces no sensible difference in the range of the piece; and therefore, that every one may please himself in the length of his barrel, without either detriment or advantage to the range. The circumstance of a duck-gun killing at a greater distance than a fowling-piece is not owing to its length, but to its greater weight and thick ness, allowing the charge of powder to be doubled, trebled, or even quadrupled; which cannot be done in a fowling-piece, though strongly reinforced. For a barrel of five or six feet, such as that of a common duck-gun, weighing five or six pounds, and the whole piece twelve or thirteen pounds, may be fired with a very large charge, without recoiling so much as to hurt the shooter, its weight being sufficient to resist the violent impulse occasioned by the increase of the powder. But in a fowling-piece of three feet barrel, sufficiently strong to withstand such a charge, and whose weight all together does not exceed five or six pounds, the recoil would be insupportable. Besides, they not only double or treble the powder in a thick gun, but they put in a much greater quantity of shot than is ever employed in a fowling-piece. Duckguns are generally bent a little upwards near the muzzle, which the gunsmiths say makes them throw their shot farther than if they were perfectly straight. To obtain, therefore, from a piece of the ordinary length, the same effects as from a duck-gun, nothing more, perhaps, is necessary than to have the barrel sufficiently strong to admit of the charge being doubled or trebled as required, and the whole piece heavy enough to render the recoil supportable. We may here observe, however, that an increase of the powder above the charge generally used, does not produce a proportional increase of range in the ball or shot: thus a double charge of powder will not throw the ball or shot twice the distance, nor a treble charge to three times the distance the single charge does. This arises from the great resistance given by the air to the motion of the ball or shot, and which is proved to be fourfold if the velocity be doubled, and ninefold when it is trebled by an increase of powder; for the resistance of the air is not proportional to the velocity itself, but only to the square of the velocity. Thus Bernoulli, a professor in Basil, discovered from experiment, that a ball, which, being fired, ascended only seven thousand eight hundred and nineteen feet in the air, would ascend fifty-eight thousand seven hun'dred and fifty feet in vacuo. Still we may safely infer, that, if the action of the powder is not diminished by circumstances of defect in the formation of the barrel, the greater the force of the powder, the greater must be the velocity of the ball. So great is the change in opinion of late, with regard to the proper length for gun-barrels, that many gunsmiths will now tell us, that short barrels carry farther than long ones; and the reason they give for this is,the greater friction of the ball or shot in passing through a long barrel, by which their velocity is retarded and their force diminished. If the bar rel be so long that the additional impulse which the ball or shot is continually receiving in its passage becomes less than the friction between them and the sides of the caliber, then, indeed, the barrel by being shortened will shoot with more force: but, as the length of barrel required to produce this effect is vastly greater than can ever be employed for any purpose, the objection does not hold. And it seems clear, that a piece may be Inade so long, that it will not throw a ball with so great a velocity as one that is considerably shorter; and the reason of this decrease of velocity may be, that in very long pieces the increase of the counter pressure of the external air in the cylinder may greatly exceed ti e force of the powder, and that the elastic finid generated by the explosion of the powder is constantly escaping whilst the ball passes along the cylinder, which it not only does at the touch-hole, but also between the ball and the sides of the barrel; and hence may be inferred the necessity of touch-holes which do not prime of themselves, and of wadding that stops the barrel hermetically. Having thrown every light upon this question that is necessary to determine us in our choice of the length, it will, perhaps, be expected that we give our opinion what length of barrel is best calculated for general use. The barrels which are found to answer best for every purpose, are from thirty-two to thirty-eight inches; and whether we consult the appearance of the piece, its lightness, or the ease with which it is managed, we believe that a barrel not exceeding the one, or below the other, of these numbers, is the most eligible. We know that many of the fashionable gunsmiths pique themselves on the proportion they give to the different parts of their fowling-pieces, and thence deduce a superiority over their cotemporaries in favour of their own: to us it appears that the beauty of those proportions is more attended to, than any good reason why they are made so rather than otherwise. Of the causes of scattering shot-From the prejudices which obtain so generally among sportsmen and gunsmiths, respecting the shot of fowlingpieces, it is very natural to suppose, that a variety of means have been sought after and practised, in order to remedy this real or pretended effect of scattering the charge. Mr. de Marolles mentions several methods employed for this purpose, none of which, however, appear to be practised in England. One of the methods he describes is as follows: An iron or wooden mandril, fitted to the caliber, is furnished at one end with small files, which are cut transversely only; this instrument being introduced into the barrel is turned round by means of a cross-handle, and forms a great number of superficial scratches in the metal, by which, they pretend, the defect of scattering the shot is remedied. One obvious effect of this operation, is, that of destroying the smoothness of the barrel within, and thereby reir dering it liable to dirty the sooner; but we cannot conceive how the shot should be thrown closer by having the friction increased between it and the sides of the caliber; and that this will be the case, is evident from a rough barrel being always found leaded considerably after every discharge. Some make the barrel wider for three or four inches at the muzzle; and this bell-mouthed form is of very ancient date. Espinar says he has generally found this succeed in inaking barrels throw their shot closer. Were this true, we should expect to find this form of the barrel more generally used than it is at present, and not hear so many complaints among sportsmen about their pieces. When we consider that the grains of shot which are in actual contact with the sides of the barrel compose upwards of half the charge, we cannot be surprised if enlarging the surface of the caliber at the muzzle, and thereby increasing the number of grains that touch it, will tend to make the shot be scattered more widely. Espinar says, that the fault of scattering the shot is not owing to the hand of the workman, the barrels of the best masters being equally subject to it as those of others. He is of opinion, that it arises from the different quality of the iron composing the several portions a view to the shot being thereby thrown farther, as, by so doing, the increase of the range will be very trifling, whilst the dispersion of the shot will be greatly increased. The only expedient in this case, is, to employ shot of a larger size, the quan of the barrel. Thus he says, it may happen that the reinforced part is formed of iron which is harder, and closer in the grain, than that forming the fore part of the barrel; in consequence of which, and also from the fore part being so much thinner, the latter is the more shaken by the pow-tity of it, and of the powder, being kept the same der, and by that means produces a dispersion of the shot. He therefore pretends, that widening the muzzle in the manner already spoken of, by facilitating the explosion, diminishes the force of the powder upon this part, and causes the shot to be thrown more closely together. This opinion of Espinar, however, not only appears absurd in itself, but there is not even the smallest ground for it in the greater number of instances; the barrels which are forged in separate pieces being very few indeed, compared with those that are forged in a single piece, and are consequently of the same quality throughout: nor does it appear that the former are more liable to the fault in question than the latter are. Some gunsmiths, says Mons. de Marolles, pretend, that a barrel, in order to throw its shot closely, ought to have a caliber narrower in the middle than at either breech or muzzle; whilst others, again, insist that the caliber ought to contract gradually from the breech to the muzzle. With respect to these contrivances, however, we shall only observe, that they are both admirably calculated to make the piece recoil, if not to burst it. Of all these contrivances, not one appears cal culated to answer the end for which it was proposed. The greater number of gunsmiths are sensible of this, and therefore very seldom practise them, unless to indulge the whim of their custom ers. As far as our reason and experience are sufficient for enabling us to determine upon the matter, we would reject all the expedients that have been hitherto proposed, and give a decided preference to the barrels as they are usually made, i e. to those whose caliber is very smooth and perfectly cylindrical throughout. Barrels of this kind have long supported their credit among the best sportsmen, whilst the pretended improvements have all experienced but a very temporary reputation, and are now almost entirely neglected. Would sportsmen only forbear to determine upon the merits or defects of their pieces, until they had given them a patient and impartial trial, by varying the quantity of powder and shot in different ways, we are inclined to think there would be fewer complaints made of the modern fowlingpieces. The chief source of error appears to be that of overcharging. Every barrel, according to its caliber and weight, has a certain quantity of lead, and a suitable one of powder, which will be attended with greater certainty and effect than any others; and these must be determined by repeated trials. If we increase the quantity of shot above this, we lessen the force of discharge, and at the same time increase the recoil: and if we increase the charge of powder, that of the shot remaining the same, we also increase the recoil, and disperse the shot much more than before. In every species of fire-arms, large charges of powder are found to disperse the shot very much, whilst with smaller charges than are generally employed it is thrown more steadily and closely. If the object, therefore, which we are about to fire at, be at too great a distance for the shot to take effect, and it happens that we cannot approach nearer to it, we ought not to increase the quantity of powder with as has been already found best suited to the piece. We cannot venture to determine what degree of closeness or dispersion in the shot will entitle any piece to the name of a good or a bad one; but would observe, that if a fowling-piece, charged with an ounce of No. 2, patent-shot, and a drachm of powder, throws sixty grains into a sheet of paper eighteen inches by twenty-four, at the distance of fifty paces, we may consider it as very capital, although these are only about one-third of the charge; and that the same piece continuing to be fired at the same mark and distance, will not, in the mean of four or five successive discharges, throw thirty-six grains into the paper; in short, that, when due attention is paid to finding the suitable quantity of powder and of shot, one piece will perform nearly as well as another. Of rifle barrels. It has been found that the flight of balls, both from cannon and small arms, is liable to very considerable variations; and that the piece, notwithstanding it was firmly fixed, and fired with the same weight of powder, sometimes threw the ball to the right, sometimes to the left,' sometimes above, and at other times below the mark. It has also been observed, that the degree of deflection increases in a much greater proportion than the distance of the object fired at: thus, at double the distance the deflection of the ball from the line on which the piece is pointed is considerably more than double, and at treble the distance more than treble what it was in the first. Mr. Robins secured a musket barrel upon a block of wood, and firing it with a ball, at a board of a foot square, sixty yards distant, found that it missed the board only once in sixteen successive discharges; yet when fired with a smaller charge, at the distance of seven hundred and sixty yards, it sometimes threw the ball one hundred yards to the right, and at other times one hundred to the left of the line it was pointed in. The direction upwards and downwards also was found equally uncertain, the ball sometimes bending so much downwards as to fall two hundred yards short of its range at other times. Yet the nicest examination could not discover that the barrel bad started in the least from the position in which it was first fixed. It is impossible to fit a ball so accurately to any plain piece, but that it will rub more against one side of the barrel than another, in its passage` through it. Whatever side, therefore, it rubs against on its quitting the muzz e, it will acquire a whirling motion towards that side, and will be found to bend the line of its flight in the same direction, whether it be to the right or the left, upwards, downwards, or obliquely. This deflection from a straight line arises from the resistance which the air gives to the flight of the bullet, it being greatest on that side where the whirling motion conspires with the progressive one, and least on that side where it is opposed to it: thus, if the ball, in its passage out, rubs against the left side of the barrel, it will whirl towards that side; and, as the right side of the ball will therefore turn up against the air during its flight, the resistance of the air will become greatest on the right side, and G 2 the ball be forced away to the left, which was the direction it whirled in. If the axis round which the ball whirls preserved its position during the whole of the flight, the deflection would be in the same direction from the one endof the track to the other. But, from accidents that are unavoidable, the axis of the whirl frequently changes its position several times during the flight; so that the ball, instead of bending its course uniformly in the same direction, often describes a track that is variously contorted. So great, however, is the tendency of the ball to deflect itself towards the side it rubs against, that although, when fired out of a barrel that is bent towards the left hand, it will be thrown from the piece in the direction of the bend, yet as the ball in this case will be forced to rub against the right side of the muzzle, and thus turn its left side up against the air, so it will be found to alter its course during the flight, and bend away towards the right hand, so as to fall a considerable way to the right of the line in which the piece was pointed. From what has been said, it will readily appear, that these variations will be more frequent and considerable when the ball runs very loose in the piece; or when, from any roughness on its surface, or on the inside of the barrel, a considerable degree of friction takes place between them. With a view to prevent friction, it has been proposed to grease the ball; but this will be of little service. All that can be done in a plain barrel, is, to have the balls cast very solid and true, and afterwards milled in the same manner as is now practised upon shot: the barrel also should be very smooth on the inside, and the ball fit it very accurately, so as to leave scarcely any windage. And yet, with the help of all these, it will still be very difficult to prevent it altogether; for gravity will constantly act, and friction on the under side will naturally be occasioned by the weight of the ball. From considering the causes of this aberration in the flight of bullets, it will be pretty evident, that the only means of correcting it is by preventing the ball from rubbing more against one side of the barrel than another in passing through it; and by giving to the bullet a motion, which will counteract every accidental one, and preserve its direction by making the resistance of the air upon its fore part continue the same in every part of the flight. The contrivance for this purpose is termed rifling, and consists in forming upon the inside of barrels a number of furrows, either in a straight or spiral direction; into these the ball is moulded, and any rolling motion along the sides of the barrel, in its passage out, thereby prevented. Barrels of this construction have been in use upon the continent since the middle of the sixteenth century, but were little known, and still less employed in England, until within these fifty years. The spiral rifled barrels, however, have entirely superseded the straight rifled ones, because although the latter prevented the rolling motion of the ball that takes place in a plain barrel, yet they do not communicate any other motion, that could serve to correct the variations that may occur during the flight. The furrows, or channels, which are termed the rifles, vary in number according to the fancy of the workman, or that of the purchaser, but are never less than six, or more than twelve, in a common-sized piece. Their depth is equally sub ject to variation; but the breadth of the furrows and of the threads is generally the same. In some pieces, the spirals make a half turn, in others three-fourths, and in others, again, an entire revolution in the length of the barrel: an entire revolution, however, is the most common, though, from the great difference in the length of rifle barrels, there should be some standard assigned for the obliquity of the spiral. There is, without doubt, a certain obliquity of the spirals which would communicate a rotary motion to the ball, sufficient to correct any aberration in its flight; and this might be determined by comparing the effects of a number of pieces, that differed only in the obliquity of the rifles. Barrels intended to be rided are previously bored and smoothed within, in the manner already described: they are, however, forged as much thicker than plain barrels as the depth of the rifles; for, although the threads of the spiral add to the weight of the barrel they do not increase its strength in the least, with regard to the force exerted upon it by the powder. These pieces are charged in various ways. In general, the ball, which is somewhat larger than the caliber before it was rifled, is driven down to the powder, by means of an iron rammer, struck with a mallet, whereby that zone of the ball which is in contact with the sides of the barrel becomes indented all round, and is moulded to the form of the rifles. When the piece is fired, the projec tions of the ball which fill the rifles, being obliged to follow the sweep of the spiral, the ball thereby acquires a rotary motion upon an axis that corresponds with the line of its direction; so that the side of the bullet which lay foremost in the barrel continues foremost during the whole of the flight. By this means the resistance of the air is opposed directly to the bullet's progress, and not exerted more against one part than another of that side which moves foremost; and accordingly the bullet preserves the line of its direction with very great steadiness. It appears that neither the inventors of spiral rifle barrels, nor the persons who first used them, were at all acquainted with the principles upon which they produced their effects. Some were of opinion, tlfat, owing to the ball not passing out so quickly as out of a plain barrel, the powder was more completely inflamed, and thereby exerted a greater force upon it. Others, and these by far the greater number, thought that the ball, by combining the rotary with the progressive motion, did, as it were, bore the air; thereby flying much farther, and penetrating solid bodies to a greater depth, than when discharged from a plain barrel. But Robins asserts, that as the bullet meets with a greater resistance in its passage through a rifled barrel than through a plain one; so neither its velocity, nor the distance to which it is thrown, is so great when fired from the former as when fired from the latter: and this difference will be very remarkable if the rifles be deep, and the ball fills them up completely; the friction, in that case, bearing a considerable proportion to the force of the powder. For the same reason, he says that barrels which are newly rifled, and, consequently somewhat rough within, do not throw their balls so far as they will be found to do after being used for some time, and thereby rendered smoother; and, that the mistake of those who supposed that ride barrels threw their balls to a greater distance than plain barrels did, arose from their finding, that, with the former, they could hit a mark at three or four times the distance they could do with a plain barrel. Besides the method of loading a rifle-barrel gun, by driving down the ball with an iron rammer, there are several others which we shall mention. In Germany they sometimes charge them in the following manner: a piece of thin leather or fustian is cut into a circular shape, and so large as to cover a little more than half of the ball; this piece is then greased on one side, and, being placed over the muzzle, the ball is laid upon it, and both thrust down together; by this means the lea ther or fustian enters into the rifles, and the bullet, being firmly embraced by it, acquires the proper rotary motion in its passage through the barrel. If this method be equally effectual, it is certainly much more easy and expeditious than that already described. Some of the old pieces of this construction were charged by taking out the breech every time; and we are informed, that the pieces used by the Hessian yagers are charged the same as the common screw-barrel pistols. By far the most expeditious way of charging rifled pieces, however, is, by means of an ingenious contrivance which now generally goes under the name of Ferguson's rife-barrels, from its having been used by major Ferguson's corps of rifle-men during the last American war. In these pieces, there is an opening on the upper part of the barrel, and close to the breech, which is large enough to admit the ball. This opening is filled by a rising screw which passes up from the lower side of the barrel, and has its threads cut with so little obliquity, that, when screwed up close, a half-turn sinks the top of it down to a level with the lower side of the caliber. For, when the ball is forced through the rifles by the effort of the powder, the friction must be considerably more than when it is moulded to them in the ramming down. It appears, however, that in whatever way the piece is charged, this friction might be much diminished, by making the channels or furrows very broad in proportion to the breadth of the threads, and, instead of leaving the latter flat on the top, to have them terminating in a sharp edge, whereby they would cut easily into the ball. This would also serve to lessen the additional quantity of metal in the barrel, which, as the rifles are now formed, bears a very considerable proportion to the weight of the whole piece. The depth of the rifles, likewise, need not be great, as a very slight hold of the ball is sufficient to communicate the desired motion: deep rifles are particularly detrimental when the piece is charged at the breech; for, if the ball be large enough to fill them up entirely, the resistance, and consequently the recoil, will be very great; and, if it does not fill the rifles, there will be so much windage, that a considerable portion of the flame will escape past it, and the force of the discharge be thereby greatly lessened. To render rifle barrels as complete as possible, we should endeavour, by every means in our power, to diminish the friction between the bullet and the sides of the barrel. We have already mentioned some alterations which we think would conduce to this. The turns of the spiral being exactly parallel to each other, and both the threads and the furrows being made perfectly smooth, are circumstances absolutely essential to perfection; as thereby the bullet, when once put in motion, will pass through the barrel with very little friction. The most accurate method of as certaining this is, by pouring melted lead into the barrel so as to form a cylinder of two or three inches in length, and which is exactly fitted to one portion of the caliber: if the cylinder, when moved a little, passes without stop or difficulty, from one end of the barrel to the other, by being pushed gently, the rifling may be pronounced very exact. The same thing may be tried with a plug or ball of lead, driven into one end of the barrel so as to fill the rifles, and pushed forward with a ramrod. From the imperfect manner in which any instru ment works in a spiral direction within the barrel, the furrows are generally left very rough; and hence rifled pieces are found to throw their ball to a greater distance, though with equal accuracy, after being used for some time, and thereby hav ing the bottom of the furrows, and edges of the threads, worn smooth. These might be rendered smooth at first, by means of a plug of lead or pewter, made to fit the rifles, being fixed to an iron rod, and wrought backwards and forwards in the barrel with fine emery and oil: or the leaden plug might be employed as a pattern to form one of brass or steel by, for the same purpose. As the pieces which are charged at the breech are considerably dearer than the others, and, excepting the expedition with which they can be charged, are really inferior to those charged at the muzzle; we are of opinion, that the latter might, by a very simple means, be rendered equally serviceable with the former. This is nothing more than having the balls cast with projections that answer to the rifles; which may be done with great ease and accuracy by making corresponding hollows round a zone of the bullet-mould: by this the ball may be fitted so accurately to the rifles, as to leave scarcely any windage; whilst the friction will be less than it is either when the ball is put in at the breech, or forced in by the muzzle. In treating of the causes of aberration in the flight of balls, we have supposed the air to be perfectly still, it being evident, that the force of the wind will affect balls considerably, whether they are fired from a plain, or from a rifled barrel; but, for the reasons already given, will affect the former in a much greater degree than the latter. Pieces intended for shooting with ball, whether they be plain or rifled, ought to be of much more equal thickness from the breech to the muzzle, than those that are intended for shot only. In every barrel, there is an undulating vibration communicated to the metal by the explosion. This is most remarkable in a thin barrel, and when the charge is great; and may be rendered very evident by the following easy experiment: Take a piece of fine steel or iron wire, that is tempered so as not to stretch readily; pass it once round the thin part of the barrel, and twist it tight. The piece being then charged and fired, the wire will be found burst asunder, or considerably untwisted. It is evident that such a degree of vibration in the barrel must have an effect upon the ball in its passage through it; and that the only means of preventing it is, by having an additional quantity of metal in the barrel, and especially in the fore part of it. The same circumstance certainly obtains, though in a much less degree, in fowling-pieces; and, on this account, as well as on that of the recoil, a barrel which is strong enough to withstand any charge that is required, may yet have too small a quantity of metal in it. Having now fully explained the principles upon |