of protection proportionate to its weight. Granting this, he maintained that there were circumstances under which iron alone could not be advantageously used, and that this was one. Dr. Eddy alluded to the difficulty now felt in securing the iron plates on the sides of the vessels without weakening them by perforating holes, and he mentioned a plan of screwing the plates within a railshaped frame, which he said he had been encouraged by Mr. Fairbairn to lay before the Section, and which he thought would obviate the difficulty.

believed it could be done, and if it could be done anywhere it was in England. The construction he would propose was that to which Sir W. Armstrong alluded and approved of on the previous day, the coiling of steel wire round a central cylinder. With a six hundred pound gun of this construction the iron plates would have no chance.

The Chairman remarked that they had better confine their attention to the two hundred pound gun, which was all they had got at present. Capt. Blakely admitted that with the two hundred pound gun the iron plates would have the best of it. He had offered over and over again to make a gun' of the description he had named at his own expense and place it at the service of the Government for trial, and the offer had been refused. With all respect, he must remark that it was not philosophical for the Government to refuse his oft-repeated offer, and to go on building ships with the conviction that such guns could not be made. He, however, announced that since the last meeting of the Association the Ordnance Select Committee had acknowledged the correctness of his theory that in building up cannon each layer must have a definite strain; he therefore asked the meeting to place some confidence in his assurance that guns could and would be made to smash any armor-plate which a ship could carry.

Capt. Blakely R.A. then brought forward his paper "On Artillery versus Armor."He said it was now four years since he first developed at Dublin his ideas with reference to the strength and extent of range which might be obtained with a particular description of cannon. He was happy to think that the principle he then contended for had since been recognized by both the English and Spanish Governments to be correct. With great deference to the opinion of Sir William Armstrong, he must state, as the result of his experiments, that nearly every kind of steel he had used was better than every kind of wrought iron. Cast iron, where weight was no objection, he found to answer admirably. Capt. Blakely exhibited the drawing of the new Spanish gun, and explained its construction. The diameter of the bore was between six and seven inches; more than half of the gun, he said, was of cast iron, the upper portion of the breech only being formed of rings of steel Extensive experiments had been made to determine the proper degree of tension for these rings, because on that point depended the efficiency of the gun. If the rings were too tight, they burst before the central part, and if they were too loose the central parts burst first, and perhaps left the rings whole. He did not think that any limit could be as-was quite so good as some produced in other signed as to the size which would be reached countries. The iron itself was good, but it in the manufacture of guns. The whole ques- had not that uniformity of texture which tion of armor hung on the cannon which it was obtained in foreign countries. Our had to resist. He had read that Sir William iron-masters, he believed, were bestowing Armstrong was engaged in the manufacture attention on the subject, and in a short space of a three hundred pound gun. He (Capt. of time would, he believed, be able to proBlakely) was trying to make a six hundred duce such plates as would have a fair chance pound gun, and by using wire he did not of resisting such artillery as Sir William think there was any insurmountable diffi- Armstrong's. It was the intention of the culty in making a six thousand pound gun, committee to do every thing they could to or even a sixty thousand pound gun. He resist Sir William Armstrong, and he on

Mr. Fairbairn, President of the Association, as one of the Committee (of which Sir J. D. Hay was chairman) appointed to conduct the experiments at Shoeburyness, gave some of the results of the experiments made. Apologizing for his not having been able to prepare a written report, he stated that one of the results of the experiments made was to convince him that, though we had very good iron in this country, yet he did not think that the quality of the wrought iron

broader, five hundred and eighty-two tons additional burden, and twelve hundred and forty-five tons additional displacement; and

his part would of course do every thing he could to smash them up. In the case of armor-plated ships, it was not only necessary to have plates of sufficient thickness, as the displacement was the actual measure but to have sufficient resistance behind to resist the deflexion caused by the shot. In the Warrior and the Black Prince wood was used for this purpose. His own opinion was, that wood was entirely unnecessary, and that every part of the vessel above the water-line would be better of iron. Experiments had been made to test the velocity of the shot from the Armstrong gun, and it was found to be about eleven hundred feet per second. Mr. Fairbairn referred to the necessity of securing toughness and homogeneousness in the plates, and also the desirability of securing a better mode of attachment than the present system of using bolts or screws. They had tried experiments with a target composed of iron bars; but they found that the resistance offered was not nearly so great as by the iron plates. The experiments would be continued, and in a few months the committee hoped to arrive at a definite result with regard to the proper thickness of the plates, the mode of attachment, and the quality of the iron.

of the ship's size, they would thus be more than 1,000 tons larger than the Warrior. As the engines of the new vessels were only to be of the same power, their speed would probably be much less than that of the Warrior. This diminished speed was one of the penalties we must pay for clothing both extremities of the vessel with iron plates. Another penalty would probably be a great tendency to chop and plunge in a sea-way. The cost of these new vessels would exceed the cost of those of the Warrior class by £20,000 or £30,000. They would certainly be noble specimens of war ships. A vessel built throughout of iron four hundred feet long and nearly sixty feet broad, enveloped from end to end in armor impervious to all shell and to nearly all shot, furnished with the most powerful ordnance, with ports nine feet six inches above the water-line, steaming at a rate of twelve or thirteen knots an hour, would indeed prove a most formidable engine of destruction. If the present intentions of the Admiralty were carried "On the Iron-cased ships of the British out, we should have six of such vessels Admiralty," by E. J. Reed.-He enumer- added to the navy in the next year or two. ated and described the vessels at present con- In vessels of this kind all beautifying destructed; and stated that the construction vices must be dispensed with. Their stems of six other vessels had been determined were to be upright, or nearly so, without upon, the contracts for three of this number that forward reach, the "knee of the head," having already been issued. It was impor- which added so much to the beauty of the tant to observe that, notwithstanding the present vessels. Their sterns would also be long delay on the part of the Admiralty before upright, and as devoid of adornment as the they commenced the construction of vessels bows. It should also be stated, as a distinof this class, the determination of Parlia- guishing mark of these six ships, that their ment to have a fleet of iron-cased ships had thick plate would not be extended to the even now overtaken the Admiralty, and no bow at the upper part, but would stop at the experiments on a large scale had yet taken junction with the transverse plated bulkplace. The great expense it would be nec- head, some little distance from the stem, essary to incur to conduct target experi- and this bulkhead would rise to a sufficient ments on a large scale had probably much height to prevent the spar deck from being to do with the delay. A committee of emi- raked by shot. They would be armed with nent ship-builders had lately estimated that fifty 100-pounder Armstrong guns, forty on the cost of a target large enough to test the main deck and ten on the upper. It was half a dozen modes of construction would not yet determined, he believed, whether be no less than £45,000, and another £45,- these new ships were to be backed up with 000 would have to be expended in the con- teak, as in the previous ships, or whether struction of a floating hull on which to the plates should be six and a half inches place the target. The three new ships in thick, without wood. This would not be decourse of construction would be twenty feet cided upon until after the termination of the longer than the Warrior, fifteen inches experiments with the large targets suggested

A vote of thanks to the readers of the papers, proposed by the Chairman, was carried by acclamation.

by the President and others. All that was on the Southampton Water; and in some yet definitely determined was, that whether other favorable places. At present we had the armor be made of iron alone or of iron no docks fitted in all respects to receive such and wood, its weight should be equal to iron ships, whereas the French had many. Mr. plates six and a half inches thick. He now Reed contrasted the English and French came to notice a very different class of ves-docks; and stated that it had been prosels, of which the hull was mainly timber posed to increase the French works by the with armor plated upon it. The Royal Al-establishment of an immense steam arsenal, fred, Royal Oak, Caledonia, Ocean, and Tri- protected by a series of impregnable forumph were all vessels of this class. Their tresses at Lezardrieux. length was to be two hundred and seventytwo feet, breadth fifty-eight feet, and displacement 6,839 tons. Each would be fitted with engines of one thousand horses' power. Sir J. D. Hay rose, at the request of the They were formed with timber originally de- President of the Association, to supplement signed for wooden line-of-battle ships, but his remarks on the experiments at Shoehad been lengthened eighteen feet. The buryness with some observations of his own. whole of these ships, it was believed, as well The committee, he said, in order to ascertain as the iron-plated ships, would match La the best quality of material, the best thickGloire in speed, provided they were fitted ness of metal, and the best mode of manuwith the engines at first proposed. It was facturing iron plates, invited the leading necessary to make this proviso, because there manufacturers of the country to place bewas a probability of smaller engines being fore them specimens of iron plates which put into some of them. He could not pre- they considered best adapted for the purtend to compare the French and English poses required. Plates, varying in thickships with each other in detail; but he mightness from one-fourth inch to ten inches were mention that a friend of his, who had just sent in. The committee found on making returned from France, had furnished him experiments, that the steely description of with the dimensions of the Solferino, one of metal, that was to say, metal which had the largest of the French iron-cased ships, been hardened, and went by the names of as follows: Length two hundred and eighty- semi-steel, homogeneous iron, etc., up to a two feet, breadth fifty-four feet, draught of thickness of three-fourths of an inch, poswater twenty-six feet, burden 6,820 tons. sessed great resisting powers, but after that The vessel will be plated with 4 3-4-inch thickness, this description of metal was not plates, right fore and aft at the water-line, so well qualified to resist a blow of a proand over two decks amidships. With ref-jectile as wrought iron of the best kind. erence to the cost of iron-plated vessels, Mr. Reed said that, assuming the average cost of the ships to be £50 per ton, and the engines £60 per horse power, then the eighteen ships we were now building would cost about £4,700,000, and their engines above £1,150,000 together nearly £6,000,000 sterling; and when masted, rigged, and fully equipped, £8,000,000 would have been expended upon them. He referred, in conclusion, to the extensive dock changes which this revolution in ship-building rendered necessary, and urged the serious importance of at once supplying increased dock accommodation in the south of England for these ships. He argued that whether in peace or in war such accommodation would be required; that it would be in the highest degree perilous longer to defer the establishment of colossal docks

This having been ascertained, another law had been pointed out to them which they were not yet in a position fully to recognize. It was that the resistance of the plating increased with the square of its thickness. Thus, if the resistance of a plate one inch in thickness was equal to one, the resistance of a plate two inches in thickness would be four; four inches in thickness, sixteen; and six inches in thickness, thirty-six. Considerable difficulty was felt in fastening the plates upon the sides of the vessels, as it was felt that all holes drilled in them were a source of weakness. Mr. Scott Russell had a plan of fastening the plates, which, perhaps, he would explain to the meeting. Their great fear was not of a solid missile being driven through the ships' sides, but of the possible materials the shot might con

tain. They could scarcely hope effectually through which it is propelled. In short, it to exclude cold shot, but they did think it has a longer and truer flight. The essential was possible so to construct a ship and so to condition to the efficiency of the long projecplate it, that a hollow missile impinging tile is, that it shall move onwards with its upon its sides would be broken to pieces, point foremost; if it turns over in its path, and consequently they hoped to be able to it presents a large surface to the action of exclude all shells, red-hot shot and shot filled the air, its flight at once becomes irregular, with liquid iron, which were amongst the and is rapidly retarded. The action of the most terrible weapons of modern warfare. common spinning-top suggests at once the In the course of their experiments they had idea that the best mode of making the elontried the effect of the shells upon an old gated projectile move steadily through the brig, the Hussar. At the twelfth round the air with its point foremost is to give it rotabrig was on fire beyond the possibility of ex- tion round its axis of progression. The tinction. He thought it a misfortune that rapid revolution of the body causes its inthe stem and stern of the Warrior were not herent inequalities to be rapidly carried better protected—and the steering apparatus round a constant axis in regular order, and was placed in that part of the ship from a kind of balance is thereby established, which the missiles were scarcely excluded which gives the body a steady motion. Vaat all. He thought it a wise determination rious plans have been from time to time on the part of the Admiralty to convert the tried with the object of imparting to long wooden line-of-battle ships laid down into projectiles a steady flight; they have been armor-plated vessels of great size and speed. made with spiral grooves cut externally on In the course of the Shoeburyness experi- their periphery, or internally from front to ments they had found that at whatever angle rear, in the expectation that the resisting acthe targets were placed the fracture made tion of the atmosphere acting on the inby the Armstrong gun was just as large, clined surfaces would give the requisite spinthough it differed somewhat in shape, accord- ning motion. Again, they have been made ing to the angle. He could only account for very long and furnished with fins or feathers, this fact by supposing that the damage was in order that they may be propelled on the done by the instantaneous concussion, and principle of the arrow, but no practically not by the shot boring or punching a hole successful results have as yet brought prothrough. jectiles of this kind into use. The required object is, as is well known, readily and successfully effected by propelling the elongated projectile from a rifled barrel, that is, a tube having its interior made of such a spiral form that the projectile while it is propelled from the breech to the muzzle is turned round its axis of progression: a rotatory motion is thus imparted, which is retained by the advancing projectile and gives it the required steady motion. The elongated bullet was first used with rifled small-arms, either poly-grooved or fluted, or, like the Enfield, having three grooves. The length, however, was limited : and various attempts were made to fire longer projectiles compounded of various metals and of various shapes, so that by changing the position of the centre of gravity they might be propelled point foremost. But if made beyond a certain length they were always found to turn over at moderately long ranges. Mr. Whitworth . was the first to enunciate the principle that projectiles of any requisite length could be

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Mr. T. Aston read a paper " On Elongated Projectiles for Rifled Fire-arms."After alluding to the improvements that have been made in war projectiles, which have resulted in the elongated form, he proceeded to notice the advantages which it possesses over the old spherical shape. The elongated projectile, presenting to the resisting atmosphere a sectional area considerably less than the spherical of the same weight, is less retarded in its progress through the air. It follows, therefore, that although the spherical projectile with a similar charge of gunpowder is more easily set in motion, and has a greater initial velocity than the elongated form, and to that extent has at the outset an advantage, the elongated form is much better able to overcome the resistance of the atmosphere, and owing to its superiority of momentum preserves its progressive power for a much longer period, -at the same time it is less disturbed by the varying conditions of the elastic medium

successfully fixed by giving them rapid ve- conditions most favorable to precision and locity of rotation, which should be increased range. He, after numerous corroborating in proportion with their increased length. experiments, decided that the projectile of He, as is well known, uses rifles having a the form exhibited to the meeting was the spiral polygonal bore, in which all the in- best. It has a taper front, having nearly terior surfaces are made effective as rifling the external section of what mathematicians surfaces. The success of the elongated pro- term the solid of least resistance, the curve jectile having been established in the case being somewhat rounded; the rear is made of small-arms, their employment with ord- to taper in such proportion that the air disnance followed as a natural consequence. placed by the front is allowed readily to close Rifled ordnance were, therefore, called into in behind upon the inclined surfaces of the existence to meet the requirements of the rear part. The middle part is left parallel time. In fact, the rifled cannon may be to the required distance, to provide rifling considered as a rifled musket made with en- surfaces and obviate windage. The results larged proportions. Directing our attention of long and repeated trials show that this more particularly to the two systems of Arm- form of projectile gives much greater prestrong and Whitworth, we see in the former cision and a superiority of range, varying the coiled barrel and fluted bore formerly from fifteen to twenty-five and thirty per used for the rifled small-arm, applied on an cent (according to the elevation and conseenlarged scale. In the Whitworth cannon quent length of range), as compared with a the same system and form of rifling are used projectile of the common rounded front and which are employed for the Whitworth mus- parallel rear end. At low elevations, where ket. There is, however, a change required the range is comparatively short and the for the projectiles; they cannot, like the velocities great, the difference in the result small-arms bullets, be made of lead, for ob- of the taper and non-taper rear is not so vious reasons, such as the cost of the metal, marked as at the higher elevations, where its liability to distortion of form, and un- the mean velocities of the projectiles are resuitableness for shells. Sir William Arm- duced. But at all ranges the superiority exstrong uses a compound projectile, formed ists both in precision and velocity, as the of an iron case surrounded with a leaden elongated projectile at no practical range has coating, the rifling being effected by the a mean velocity so great as to prevent the force of the explosion in the barrel, which is atmosphere closing in behind it. One of the thus partly expended in forcing the lead most important advantages attending the through the grooves. Mr. Whitworth uses use of the taper rear is, that it gives a lower a simple hard-metal projectile, made of the trajectory, which renders errors in judging requisite shape tc fit the rifled bore by ma- distance of minor importance, as the prochine labor in the manufactory, so that the jectile which skims along near to the ground whole force of the explosion is employed to is more likely to hit a mark, especially a propel the projectile. After giving a de- moving one, than a projectile which, moving scription of the two projectiles, and point- in a more curved path, has to drop, as it ing out that the Armstrong projectile nec- were, upon the object aimed at, whose disessarily required a breech-loading cannon, tance therefore must be accurately guessed. and that the Whitworth is used at pleasure The taper shape of the rear is peculiarly for muzzle-loading or breech-loading can- well adapted for the proper lubrication of the non, Mr. Aston proceeded to notice the ex-gun, which is most essential for good shootternal shape of the projectiles. The impor- ing. With the Whitworth gun a wad made tance of giving to ships intended for high wholly of lubricating material was introspeed the shape best suited to facilitate their progress through water is now universally acknowledged; and Mr. Whitworth considered that it was necessary to ascertain, by reasoning upon similar grounds, and by ex.perimental research, what was the proper shape to give to his projectile, so that it might be propelled through the air under

duced; it obviates the necessity of washing out the piece, and the subsequent adoption of a similar wad for the Armstrong gun enabled that piece also to be used without washing out, which was at first necessary, and found to be a very inconvenient operation for a service gun. Various forms of elongated Whitworth projectiles suited for