The two descriptions of fuzes, fist. 3 and 4, are thus described by Sir W. Armstrong. " The body of the time fuze, fu. 3, is made of a directions, but only takes effect at one extremity, where it communi cates with a small quantity of powder in the centre.' The fuze is surrounded by a scale paper graduated to accord with the elevation of the gun, so that when the range of a distant object is found by trial, it is only necessary to turn the igniting aperture of the cover to the point on the fuze scale corresponding with the degrees and minutes of elevation on the tangent scale.
The concussion fuze (fig. 4.) is on nearly the same principle. " A striker with a point presented upwards is secured in n tube by it wiro fastening, which is broken on the firing of the gun; the striker being thus liberated recedes through a email space, and rests on the bottom of the tube, but as soon as the shell meets with any check in its motion, the striker nine forward and presses the detonator in front, by which means the bursting charge is ignited." To show the extreme accuracy of the Armstrong shell and fuzes, we may mention an experi ment which took place before the Duke of Cambridge and a number of distinguished officers. Two targets, each of 9 feet square, were placed at a distance of 1500 yards from the gun, and 7 shells were fired at them ; the effect of these 7 shells WM, that the targets were struck in 596 places. Similar effects were produced at 3000 yards with shells, and a target 9 feet square has been struck with shot 5 timer out of 10 shots. At 600 yards an object. the size of the muzzle of a gun can be struck almost every time with the shot or shelL The tabular statement. below will explain the advantages of rifled ordnance at long ranges, while the short ranges at low angles of elevation will be easily understood, for the reasons given under GUNNEILT and Riesz, when we remember that the initial velocity of the Armstrong 12-pounder shot is less than 1100 feet per second, while that of the ordinary 12-pounder is about 1800 feet rer second.
mature of lead and tin, cast to the required form in a mould. The fuze composition is stamped into a channel forming nearly an entire circle round the body of the fuze, and is afterwards papered and varnished on the external surface. As the shell fits accurately into the gun, there Is no passage of flame by which the fuze could be ignited. The effect is therefore produced in the following manner : A small quantity of detonating composition is deposited at the bottom of the cylindrical cavity In the centre of the fuze, and above this is placed a small weight or striker terminating in a sharp point relented downwards. This striker is secured in its place by a pin, which, when the gun is fired, Is broken by reason of the tit inertia of the striker, The detonator is then instantly pierced by thepoint and Is thus The name thus produced pulses into an annular space formed within the revolving cover, which rests on the upper surface of the fuze coin. positicm, and From this snnular space it is directed outwards through an opening, so as to impinge on and to ignite the fuze composition at any required part of the circle. The fuze thus ignited burns in both The first form of carriage employed for the Armstrong gun was the bracket carriage with recoil slide. The recoil slide is however abolished for field service pieces, though we believe it is intended to employ it. still for garrison, siege, and naval guns. 'rho field servico carriage is now in form very similar to the old block trail carriage. The trunnions of the gun however rest in moveable trunnion holes. These trunnion holes being connected together by a band of iron, a horizontal motion can be given to them round a centre or pivot. between them 117 moans of a bar, which, passing to the rear almost as far as the elevating screw, has motion given to it by a horizontal screw palming through its end. By this means the gun carriage having been brought Into the general direction of lino of fire, the gun can be most accurately laid by merely turning the handle attached to this screw without further shifting of the carriage.
The following extract from Sir W. Armstrong's speech at Newcastle, will show the great labour it cost him to bring it to perfection, and its great. power now as a siege-gun ;—" To go back to the commencement of my experiments, I may tell you that they began upwards of four years ago, my first gun having been commenced in December, 1854, and completed early in the following spriog; although this gun was constructed upon the seine principle as those which I am now making, it did not in the first instance afford satisfactory results. Schemers,
whose inrentions merely figure upon paper, have little idea of the &Beebe. that are encountered by those who carry inventions Into practice. For my part, 1 had toy full share of such tiflieultics, and it reek me nearly three years of continual application to surmount them. In the height of summer my experiments were for the most part tarried DO at the stes-east, between the hours of 3 o'clock in the morning and d ; for after that time people begau to move about and were apt to get in the way. At other 1 availed myself of the end moors belonging to my friend Mr. Ikeutnont, at Alleilieada, and there 1 bad a hut constructed on a mountain ridge, 2000 feet above the level of the ma. My targets were placed upon the opposite side of a deep A-alley, where nothing more valuable thee grouse or lean sheep ran the risk of being shot ; and well it was that such was the came fur I had constructed an inetniment for maintaining a fire upon an ebjeet (a breach, for example) after darkness had set in, and I used to awaken the denizens of the heath by firing shells at my distant target in the middle of the night ; and I may oleerve in passing that, when this instrument was fully perfected, 1 was enabled to strike a distant objet in a pitch dark night with the Mine accuracy as in broad day light. At the end of the three years I had enceeeded in bringing to maturity loth guns and projectiles. Several new guns had been made en my own neponsibility, and comitlemble expense incurred on CXpelitatnts; but all my disbursement; were refunded by the Govern ment as osesn as the results were ascertained." We have entered thus fully into the description of the Armstrong pm as tt is the gun adopted in the service. It only remains briefly to notice the Whitworth gun and the French rifled glut. The Whitworth gun hes, like the rifle [Rime), a hexagonal bore, the angles of the hexagon being roundel off. As the projectiles are very long, the inclioation of the grooves is very great. The guns with which the experiments were made in the spring of 1860, near Liverpool, were breech loaders. The following description and table of dimensions is taken from the Lectures on Artillery before quoted. "The breech is defied by a cap which screws on outside, and works in an iron hoop attached by a hinge to the side of the breech; the cap is opened back for loading, after which it is shut-to, like a door, and then screwed on to the breech by a handle fur the purpose; the vent is in the centre of the cap, and therefore in liue with the axis of the bore. For smaller ailed guns, Mr. Whitworth uses homogeneous iron, the larger guns are made of the same material, but strengthened with wrought iron hoops fixed on by hydraulic premure. The Whitworth projectile Ir hexagonal, its form cot responding to that of the bore, and it is made of cast iron accurately turned by machinery (jiy. 5); for penetrating haul eubstamess as wrought iron plates, the projectile is flat headed and made of homogeneous iron (fiy. 6). The charge is 1th the weight than itny other projectile. Mr. Whitworth has found that decreasing the hinder part of the projectile has greatly increased its range.
The French 9-pounder field piece is a muzzle loading 6-grooved bronze gun weighing about 6 cwt. The calibre is about inches, the grooves making one turn in 60 inches. The projectile is shown in tiy. 7. It has 12 leaden buttons on its exterior, that is,2 for each groove. Though undoubtedly not nearly so perfect a weapon as either the Armstrong or Whit worth, it appears to have dons good service in the late Italian campaign. It is also very simple in construction.
The French have also a bronze rifled siege gun of about the calibre of 12-pounders, and have rifled some of their heavy iron ship guns. The success of the latter is doubt ful, for iu all the experiments in this country, unless strengthened, east iron rifled guns have burst when fired except with very small charges.