HOW TO MAKE PROJECTILES. A variety of new forms of projectiles are required for these guns, as the necessity for large guns comes from the important changes in the mode of constructing ships of war covered with iron armor, and the projectiles for attacking these, successfully, must be the same, whether the enemy were opposed by our guns on ships or fortifications. Those here représented are solid shot and shell, 14 inches in diameter, and 28 inches in length. All these projectiles, it will be noticed, have their greatest displacement (as they are projected through the air) at their rear end. But their center of gravity is forward of their center of form. A shot fired from a rifled gun at high elevation, is inclined to keep the same direction or angle of its axis, about which it revolves, and during the last half of the trajectory this direction comes to be nearly a right angle to the direction of its flight. The resist ance to its forward motion is as its displacement of air. If its greatest displacement be aft, the resistance of the air (when the projectile is moving in the direction of the parallel lines) against its sides, inclines to bring the rear end of the shot backward, so that its axis coincides with the line of flight. The center of gravity being forward of the center of form, would assist in depressing the forward end of the shot, as the line of the trajectory was depressed. The figures show a longitudinal section, and a rear view of one form of my invenDtion, which has the required qualities to an eminent degree, and is thus adapted to the penetration of iron armor plates at a long range with a high trajectory, striking point foremost. The main body A, of the projectile, is of cast iron; the ring B is of steel, hardened. The front of the projectile is concave. The screw bolt C, is of iron, and merely fills a hole which is made by a suitable core in casting, to secure more uniformity in the metal while cooling. The rear portion is provided with projections D, adapted to correspond with, and fill as closely as desirable, the rifle grooves of the gun; and the orward portion is provided with three boutons or projections E, which may as already described. rest upon the lands of the gun, and which compel the forward part of the projectile, though smaller than the bore, to maintain a central position therein. The next figures are a front view and a side view of another form of projectile, intended to operate against iron armor, at short ranges. It is sólid throughout, and differs but little from. the long range projectile described, except that it has not the hollow rear-it is cored and filled with a screw bolt C, in the center, The next four figures are an elevation, and to secure uniformity in the casting, a section of a hollow shell with a rounded front, and a cross section of the same on the line 00 SE. This shell is provided with thirteen plungers aa, etc., adapted to explode by concussion. These radiate in so many directions, that some one may explode if the shell strikes in any position. A time primer is added, when it is required that the shell shall penetrate before explosion. This shell is adapted to be thrown inside of forts on elevated positions, or into cities, where from the height of the trajectory, it has been heretofore difficult to insure the explosion of percussion shells. It will usually explode upon striking, if it is tumbling end over end, and on striking in any position, excepting that of a fair blow with its rear end. Another kind of shell is shown, and the figures are a side view and a front view of Ja projectile intended to act as a time shell, and which is receive an ordinary or any improved form of This shell is constructed according to the theory adapted to herein before stated, and the greater weight in the forward part of this projectile, when the cavity M is filled with powder alone, is very marked, while the greater displacement of the rear portion of the shell, and the boutons to steady the small front portion in the gun, are like the projectiles previously described. AN ACCELERATING GUN. The attainment of a very long range, or the penetration of iron armor, requires the highest velocity possible to be attained. To meet this necessity I have provided a gun, in which the length of the gun is proportioned to the size of an enlarged chamber that contains the powder, from which is evolved a sufficient quantity of gas to keep a high expansive force against the shot a longer than ordinary time, and the use of this device is made practicable by the devices of compensation, and modes of attaining great strength exhibited in the spherical guns hereinbefore described. by his dydisting wed & de no allo dono gaidoned bis 190 best vns vig of bearing oldt sene od oba od binon Fig 3501 murga ai bonimpor anoit thus sit The figures represent a longitudinal section of the gun, and a cross section on line SS; also, an end elevation, the right hand side being an elevation of the rear end with a portion broken away, and the left hand side an elevation of the front end. A is the inner lining of steel constructed in the form represented; so that there is a chamber M larger than the main bore of the gun. This chamber M is bored without difficulty, by means known to workers in metal, and contains, in a form adapted to facilitate its rapid: ignition, a much larger quantity of powder than can be burned, with advantage, behind a shot in guns of the ordinary construction. B is a covering of bronze forced tightly upon the lining A. The inner surface of B and the outer surface of A are tapered slightly; the rear end of A being largest. This facilitates the production of a very tight fit of these parts, but care must be taken that the thickest part of the steel lining A be not too great. I prefer to make this thickness, if the gun be large, about three and a half inches, as otherwise the difference in the temperature between the inner and outer particles induces a serious strain. C, D, E and F are heavy washers of steel, prepared with a spring temper, and touching each other only at a few points by the aid of the projections, d, e and ƒ, arranged each in a different part of the circle from the next, so as not to coincide in position, but to differ as widely each from the other as possible. This, as will be readily understood from the drawing, allows the elasticity of the washers to be brought into play. G is a nut fitted upon the steel A by a screw thread, as represented. This is applied against a washer F, with considerable force, so as to compress or bend, slightly, all the washers between itself and the washer C, resting against the bronze B. H is the inner shell, and H2 the outer shell of a bronze casting which is forced, or shrunk on, over the parts before described. This casting is filled with lead, J, and compressed, and is provided with braces, H1, which connect the inner shell H, with the outer shell H2. A quantity of lead, K, is also introduced between this casting and the spherical chamber, and held by a screw, L. It will be seen that this gun possesses compenstion for unequal heating, which forms so conspicuous a feature in some of the guns before described, and, in addition, stores in its capacious chamber M, so large a quantity of powder, and allows it to burn so quickly, that the great initial pressure, which is usually felt by the projectile during the early portion of its movement, is continued further than usual toward the muzzle, acting a greater length of time against the shot to accelerate its motion, analogous to the motion of mercury in the tube of a common thermometer, due to the expansion of the large quantity of mercury contained in the bulb. If a thermometer was constructed without the bulb, the expansion of the mercury in the tube, only, would not be sufficiently apparent to give room for graduations, but by the addition of the quantity in the bulb, affected by the change of temperature, the motion along the tube is very great, and can be proportioned to give any required amount of motion in the tube, if the bulb could be made to resist the forces acting upon it. And these are exactly the conditions required in a gun, to attain the highest velocity. I believe my mode of constructing this gun, will allow the successful use of this idea, but without my plan of compensation, the structure would be destroyed by the joint effects of the high mechanical pressure and the heat to which it would be subjected. Figure 35 represents an implement I have designed, for loading such a gun. N is a cylinder of copper, and n, is a hollow wooden stock, by which it may be reached into the gun. n1, is a stop which rests in and against the muzzle, when the loader is fully in place. The cubical contents of N, are equal to that of the chamber M, of the gun. An elastic disk, or wad O, is placed upon the convex face of the plunger P, then the powder for a charge is introduced into N, next a sheet of paper R, is placed over the end of N, and, lastly, a ring S, is slipped over the edges of the paper, holding it strongly to P. The loader and its contents are next introduced into the gun, until the stop n1, rests on the muzzle. The plunger P, is then forced inward by the rod p, passing through the stock n, bursting A pivot carriage adapts this gun to be used on the deck of such ships as the Vanderbilt or the Niagara; and if the speed of the ship was greater than any iron clad, this gun would enable us to defeat all the ironclads in the world. The gun is susceptible of such adaptation, by increasing the size of the chamber, and proportionately the length of bore, as to give the highest possible velocity to the shot; and, by the principle of compensation, can be made of any required size practicable to be carried on a ship with perfect immunity from bursting. By placing the nut of the elevating screw on a spring, the muzzle of the gun can conform to the direction of the shot as it passes along the bore without breaking off the muzzle, heretofore shown to be a fault of guns as ordinarily mounted. |