EXTRACT.

"It was one day, shortly after the storming of Magdeburgh-which, thanks to the saints! had fallen before our victorious arms-when our worthy general, Count Tilly, of pious memory, had just inspected Falshimer's regiment, and was in the act of listening most mildly and attentively to Count Pappenheim, who, with his usual impetuosity, was again urging an immediate advance against the Swedes, that an officer of inferior grade stepped forward, and solicited permission to speak to our excellent leader. This man, who was stated by the few cavaliers of rank that knew him to be a mere soldado of fortune, had been present at the onslaught of Werben, and some of the other encounters which had taken place between the Swedes and Imperialists. He was said to have a knowledge of a certain science called tactics, the object of which I pretend not precisely to understand, as it refers to matters below the dignity of men of station and family, who are entitled to military rank and command by their birth alone, and who naturally leave all matters of inferior detail to the care of the trill-meisters and their assistants. This tactician, then, having advanced and made his military obeisance to the general, spoke nearly as follows:- Having served in some of the late onslaughts, I think it right to acquaint your Highness, before you proceed to meet the Swedes, that these heretic soldiers have adopted a system of tactics entirely different from that of the excellent Count George Basta, according to whose method the Imperial armada has been trained and instructed. The Swedes have intermingled small divisions of pikemen and musketeers in a manner I will not here detain your Highness by explaining, but so contrived that they can move with facility from one place to another; and can, without any change in their order de battala, employ either pike or musket as occasion may require. The men are also, individually, expert in the use of arms,—an advantage that has already cost the lives of many of our soldiers, and one that your Highness may perhaps deem it expedient to communicate to the Imperial armada before proceeding to engage these new adversaries. It was by neglecting to render the Macedonian phalanx more moveable, and the men individually more skilful in the use of arms, that Perseus was defeated by the Roman at

"Sir Cavalier,' said Count Tilly, taking off his hat, and making a polite reverence, for Tilly was a courteous man, I also have conned Livy and Polybius, but do not find in either of these writers that the Greeks or Romans knew anything about guns or gunpowder, so I do not see what good we can here derive from their example. As to the other matters you have mentioned, I thank you for the information you have brought me, and laud your zeal in wishing to improve our tactics; but the system that always made us victorious when contending against the bravest enemies in the world, though commanded by such great generals as Anhalt, Mansfield, the Duke of Brunswick, and Christian of Denmark, that system, I say, is quite good enough for me, who am always for letting well alone.'

"The princes, generals, and staff-officers present, taking their tone from the complaisant smile with which Tilly concluded his triumphant reply, were exceedingly facetious at the expense of the obscure soldado. The Butler jested in Irish, the Campbellos and Campo-bellos in Italian, the Macdonells in Gaelic, the rest in German and Slavonic. The

object of these taunts bore himself right calmly, merely saying as he withdrew, that he hoped the valour of the troops and the skill of the officers would amply atone for their tactical deficiency; and that he further trusted the gentlemen present would all be as facetious after their meeting with the Swedes as they were at the present moment; concluding with the French line,

'La raillerie est belle après une victoire.'

"Little was thought of the matter at the time, and it would most likely have soon been forgotten, had not subsequent events too painfully impressed it on our recollection. The facility, in fact, with which the Swedes moved, and the skill with which they used their arms, enabled them alone to defeat our valiant armada, even after their Saxon allies had been routed. Flight alone saved those of our host who escaped. Amongst the most distressed on this occasion, was naturally our hitherto unconquered commander: having performed wonders of generalship, he was at length obliged to fly the field, closely pursued by a Swedish ritt-meister, known, from his length of limb, by the name of Long-legged Frank. The pursuer had already wounded the noble. Tilly by firing a pistol at him, and was endeavouring to despatch our chieftain by striking him on the head with the butt-end of the weapon. At this moment there passed, at full speed, an Irish ensign, a gentleman of ancient family, and who promised to be himself the father of a long line of descendants: his name was Morgan O'Dogherty; and he was well known in our armada for his great discretion, and for the sharpness of his spurs. To him the general applied in his distress, calling upon him for instant aid against the heretic Swede; but the ensign never allowed his chivalrous feelings to get the better of his discretion: he therefore kept on his course, merely replying, Thank your grace, thank you, my own head is quite well, and I am always for following your grace's maxim of letting well alone; long life to your honour! A plague of the Irishman,' said Francis, Duke of Luneburgh, who came up at the time, and saved Tilly by shooting the Swedish ritt-meister through the body; and may the fiend drive his maxims out of his head.' • The butt-end of a Swedish pistol will do that just as well, my dear duke,' answered Tilly; I have just felt its effects, and can answer for its being a knock-down argument-sans réplique.'"

ON TERMS EMPLOYED BY PRACTICAL GUNNERS, AND ON THE IMPORTANCE OF CORRECT PRACTICE-TABLES, &c.

As a confusion of terms in the theory or practice of gunnery is to be deprecated as having a direct tendency to perplex inquirers, it is believed that any attempt to apply new meanings to old terms must be pernicious in the degree in which such attempt prevails; and it is imagined, that the truth of this proposition is so axiomatic, that any deviation from the rule resulting from it must be attributable to inadvertence, since it is not to be supposed that any man taking the trouble, or attempting to elucidate difficulties, would, in the very effort to do so, intentionally and unnecessarily generate others. It is therefore trusted, that the observations which may follow will be attributed, not to captious criticism, but to a desire to assist,

in a degree however limited, in promoting the benefit of the United Service.

The term range, in the British service, as applied to the effect of guns, has hitherto, at all elevations, conveyed an idea of the first graze of the shot on the plane which coincides with that tangent to the gun-wheel or truck which would be parallel to the axis of the bore were it laid at 0 elevation.

At page 367 of this Journal, (No. for July) J. H. has inserted a practice. table for 32-pounders, in which range is made to express, at all elevations, what the French term le but en blanc artificiel, at elevations exceeding that of the line of metal; that is, the point where the trajectory of the shot cuts for the second time the plane coincident with the centre of the mouth of the gun. So long as terms are not apt to be misunderstood, their selection is a matter of no essential consequence: perhaps the sense applied to range by J. H., if universally adopted, or rather, if adopted from the first, might have obviated some difficulties which now present themselves, particularly as the height of the bore of the gun above the plane on which the range is measured, would cease to be an object of consideration; but it would be difficult, from practice, to establish ranges upon this principle; the shot not telling upon the object aimed at, would afford no criterion, as the height of the trajectory at a particular point, not the amplitude of the curve, would be the subject of enquiry. A series of screens would, therefore, at all times be necessary; and it must be obvious, that the adoption of this change would lead to confusion, for by comparing the table of J. H. with previous practice, a great disparity must appear, particularly at elevations under 3o, since the ranges measured on the plane on which the gun stands, ought to be greater than those measured " by a line supposed to be extended horizontally from the mouth of the piece," exactly to that extent which the shot would pass over in descending the space between the parallel planes.

The naval service, in adopting tables constructed from practice made ashore and according to the ordinary acceptation of the terms range and point-blank, have only to lay their guns at a point in their adversary's side three feet and a half above the water line; then, supposing the results follow which the practice-tables promise, will the shot take effect exactly upon the water-line?

J. H. has also revived the idea of a right-line range, the limits of which he fixes at one hundred yards, as, he observes, the shot's trajectory at that distance nearly coincides with the horizontal line; and he asserts, "that the term point-blank conveys, generally, a notion of a right-line projection; and that most practical gunners understand it to be so much of the first portion of a shot's trajectory as coincides, or nearly coincides with_a_right line, when the piece is directed horizontally. Now, it is apprehended that, with the present race of practical gunners serving in the artillery, the term point-blank has never conveyed such a notion. The point-blank range is understood by them to be the range ascertained by the point whereat the shot, by its first graze, cuts the plane which coincides with that tangent to the gun-wheel which is parallel to the axis of the gun. If the axis of the bore be horizontal, the point-blank range is defined by the first graze on the horizontal plane on which the gun stands*.

J. H. may probably be a naval officer, and therefore have referred to that respectable body of men, naval gunners, who have hitherto, perhaps, been more remarkable for bravery and seamanship, than for any knowledge of the principles which influence the trajectory of shot, although the establishment recently instituted for their instruction will, no doubt, speedily anticipate every desire which might be formed for their improvement.

* We have before attempted a definition of point-blank; it may, therefore, be less incumbent on us to enlarge on this term. See Vol. vii. p. 76. At page 78 of that volume, 24th line from the top, for first, read for the second time; and at page 478, 4th line from the top, for 2384, read 3384,

It is said, that the idea of a right-line range is revived, because, towards the close of the seventeenth century, such an idea was very prevalent. Anderson, in the year 1713, published a work, in which he contended, that the first part of the course of a shot was actually in a right line; that this right-line projection was equal at all angles, and that from the end of it, the trajectory bent into a parabola. However inconsistent with a right-line projection, he was equally strenuous in support of the parabolic system, but it would be difficult, in the present day, to produce many practical gunners who would attempt to maintain either one theory or the other.

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That a cannon-shot does not descend in the ratio which the laws of gravity would ascribe to it has been long admitted. J. H. properly observes, that it cannot be adequately accounted for, from the resistance produced by the velocity of the shot's descent," by gravity, and he suggests the idea that it may be attributable to the density of the air by compression, arising from the great velocity with which shot are projected, and the resistance opposed to this dense air by the unyielding material of the earth's surface. It is very possible to imagine that the cause here suggested may influence the trajectory of the shot; if established, it would, in a great measure, account for the difficult and uncommon, though well-attested fact, that persons when standing near some unyielding material, as the mast of a ship, have been killed by what has been termed the wind of a shot; the shot having passed between them and the unyielding substance.

In addition to the ordinary resistance of the air, it may be considered, that at the velocities with which shot are commonly projected from long guns, a vacuum is created behind the ball, which, as it advances, will occasion a rush of the particles of air at a velocity exceeding 1300 feet; and, when attempting to make any inference from the laws of gravity, it may be well to remember that the theory which supposes that spaces descended are as the squares of the times of descent, also premises that the body descends freely by its own weight, and that the motion commences from a state of rest. Now it cannot be contended (setting aside the ordinary resistance of the air) that a projectile descends freely by its own weight when urged in any direction with the velocity given to cannon-shot; neither can it be asserted that the motion commenced from a state of rest, since it is certain that the gravitating force commences when the shot possesses the utmost velocity with which it is discharged from the gun. Notwithstanding the great advances made by Mr. Robins and Dr. Hutton in ascertaining the true trajectory of the shot, the truth of the assertion of the Genevese philosophers must still be admitted: " Vera trajectoriæ descriptionem adeo perplexam esse, ut ex illa vix quidquam ad usus philosophia aut mechanicos accommodatum possit deduci." Dr. Hutton has no doubt gone far to fix the laws of the resistance of the air, and to establish rules by which we may obtain very near approximation as to the velocity and range of shot, but he does not appear to have entered upon the movement of shot horizontally, in connection or combined with the vertical descent by gravitation.

From the practice on Sutton Heath in 1810, under that best of good fel-lows, Sir George Adam Wood, which was conducted, as to ascertaining the exact range, with more than ordinary care, each ten yards being pegged on an horizontal plane, it appears, by the average, that the point-blank range, or first graze of a 24-pounder, at O elevation, is 297 yards. The gun being loaded with the weight of the shot, the initial velocity may be taken at 1640 feet, which, at 297 yards, would be reduced to about 1300; the time of flight may be considered of a second; the vertical descent by gravity due to which would be 5 feet but as the gun was mounted on a garrison carriage, the height of its axis above the plane on which the graze was measured was only 3 feet. Again, the flight of the shot would be, as before observed, very near of a second, whereas the time corresponding to the vertical descent of 3 feet, is somewhat less than. It is very easy to show aided by the discoveries which have been made as to the velocity

of shot, and the resistance of the air, that a shot does not move in a parabola, but the endeavour to trace its true course and to reduce it to fixed rules is beset with very great difficulties; it has baffled such men as Newton, Galileo, Bernouilli, Halley, Robins, Euler, Lombard, Hutton. It is not on this account to be despaired of, but ought rather to excite the inquiry and to stimulate the exertions of men of science; and it is in the power of practical men, de nous autres, to aid their endeavours, by affording minute and correct returns of practice, such as, it is to be regretted, do not now exist.

The practice at Sutton Heath, however carefully the ranges might have been determined, may, notwithstanding, be quoted to illustrate the little advantage which can be derived from the data commonly afforded by practice-tables, and may corroborate the opinion formerly offered in this Journal, that the windage and the éprouvette strength of powder, as well as other particulars, should be noted. We have seen, that the point-blank-range of a 24-pounder, charged with weight of shot, is 297 yards; now the pointblank of an 18-pounder, also charged with weight of shot is, by the same authority, 385 yards. By theory, and indeed by actual experiment, guns alike charged, that is where the weight of powder for each gun is in the same ratio as their shot, should have equal velocities: how then is this difference in the range to be accounted for? It may be conjectured, perhaps relied on, that it arose from a difference of windage. The old and new guages for 24-pound shot vary 109 of an inch; the 18-pounder only 031. The windage of a 24-pounder, with old or new pattern shot, may vary from 239 to 348; of the 18-pounder, from 218 to 249 only. Unsatisfactory as the information afforded by the practice in question is, in some respects, it tends very powerfully to confirm one principle of considerable importance: heavy shot with less velocities may, with certain elevations, range farther than lighter shot with greater velocity. The following is an abstract of the media of the practice of the 24-pounder and 18-pounder, the charge being one-third the weight of shot; the metal on garrison-carriages, and therefore equally, or nearly so, above the plane on which the ranges were measured; the length of each gun nine feet six inches.

Elevation. P.B. 1°

2o

3° 4°

5° 10° 15° 21°

297 720 1000 1240 1538

1807 2870 3510 4000 385 881 1060 1340 1603 1730 2632 3190 3610

At 5° it may be observed, that the range from each gun was equal; at 10° that of the 24-pounder exceeded more than 200 yards; at 15° more than 300 yards; and at 21°, nearly 400 yards. These results are perfectly accordant with theory, and depend upon the well established rules, that the resistance of the air is as the surfaces or as the squares of the diameters of shot; but the weights of shot (or their power to oppose the resistance of the air) as their cubes.

Σ.