5o6 



NATURE 



[September i8, 1890 



the Orlando class, one being carried at the fore and one at the 

 after end of each ship. 



As a sufficient proof of the value of these mountings and of 

 thi ability which has been displayed in their design, I may men- 

 tion that practically all countries have adopted these carriages 

 for modern guns, either without any alteration or with compara- 

 tively unimportant modification. 



In discussing our modern ordnance I only alluded to quick- 

 firing guns, because in their case the gun and mounting are so 

 closely connected, the efficiency of the system depending as 

 much upon the one as the other, that a separate description of 

 either would be incomplete, and they are more easily described 

 together. The great success which attended the small Hotch- 

 kiss and Nordenfelt three- and six-pounder guns led me to con- 

 sider whether the same principle could not be applied to large 

 guns, and we designed and made at Elswick the 47 inch and 

 5 '5 inch quick-firing guns which were so successfully tried by 

 the Excellent at Portsmouth. Subsequently, with the co-opera- 

 tion of Mr. Vavasseur, various improvements were made, and 

 for the sake of uniformity in calibre a 6-inch was substituted for 

 the 5*5-inch gun. 



One of the peculiarities of these guns is in the form of the 

 breech-screw which, while on the principle of the interrupted 

 screw, is made conical, so as to simplify the action of opening 

 and closing — the principle of the ordinary rifle cartridge has 

 been extended to the ammunition for these guns. This not only 

 allows extremely rapid loading, but secures safety from ' prema- 

 ture explosions in rapid firing. The cartridges are fired elec- 

 trically, and, not having their own ignition, there is no danger 

 of exploding them either when stowed in the magazine or if 

 accidentally dropped in the handling. 



To follow the rapid movements of a torpedo boat it is essential 

 that there should be the most perfect control o'ver the gun and 

 mounting, and the most effective mode of rapid fire is to keep 

 the gun always on the object aimed at, allowing the gun itself to 

 -fire as the breech is closed. The captain stands at the side of 

 the gun, shielded by a guard-plate from the recoil, his shoulders 

 braced against a shoulder-piece which is unaffected by the 

 recoil ; his eye aligns the sights ; with one hand he works the 

 elevating or training wheel, and with the other grasps the 

 firing-trigger, or, for rapid firing, the training-wheel may be 

 thrown out of gear, and direction given by the shoulder-piece 

 alone. The mounting is a centre pivot, and, being on live 

 rollers, turns with the least effort. The gun has no trunnions, 

 but slides in a carriage which envelopes it like a sleeve. The 

 trunnions are on this carriage, so that the two are together 

 pivoted like an ordinary gun in a fixed lower carriage. There 

 is no preponderance when the gun is in the forward position, 

 and the recoil lasts for so short a time that the disturbance of 

 the centre of gravity is not felt on the elevating-gear or 

 shoulder-piece. The lower side of the carriage is formed into a 

 recoil press, the piston-rod of which is attached to a horn on the 

 rear of the gun. 



There is also a spring-box, with rod attachments to the horn, 

 by which the gun is instantly run out as soon as the recoil is 

 expended. Efficient shields are provided to protect the crew. 

 The revolving weight of the gun and mounting is 5 tons ; yet, 

 with the shoulder against the shoulder-piece, it can be swung 

 through 90° in 2 seconds, and with the gear can be trained 

 through the same arc in 5 seconds. It is possible to fire from 

 this gun at the rate of 10 to 12 rounds per minute, and on one 

 occasion 10 rounds were fired in 47 seconds ; but perhaps the 

 most striking experiment with the gun was made .at Shoebury- 

 ness, when five rounds were fired in 31 seconds at a 6' x 6' 

 target at 1300 yards, all of which struck the object aimed at. 



A trial has also been recently made between two cruisers, the 

 one armed with ordinary breech-loading, the other with quick- 

 firing artillery, from which it appears that when firing at a 

 target the latter, in a given time, was able to discharge about 

 six times the quantity of ammunition fired by the former. I 

 need not impress upon you the significance of these facts or the 

 importance of quick-firing armaments, especially if firing shell, 

 possibly charged with high explosives, against the unarmoured 

 portions of cruisers or other vessels. 



The accuracy and the shell power of rifled guns have naturally 

 had their effect upon the mountings for the land service, experi- 

 ments having conclusively shown that batteries armed with guns 

 placed in ordinary embrasures would soon be rendered untenable. 

 Among the expedients that have been adopted or suggested to 

 meet the altered conditions, the system of making the gun dis- 



NO. 1090, VOL. 42] 



appear behind a parapet or into a pit, with which the name of 

 Colonel Moncrieff has been so long and so honourably asso- 

 ciated, is more and more coming into favour as the most 

 effective mode of protection for the gun and its mounting, as 

 well as for the gun detachment. During the last ten years much 

 attention has been devoted to the designing of various mountings 

 on this system for all weights of guns from 3 up to 68 tons. 



In the earliest carriages of this type the gun was raised by the 

 descent of a balance weight, but the most successful arrange- 

 ment is that in which compressed air is employed for the 

 purpose. The 9 •2-inch and lo-inch hydro-pneumatic mountings 

 are the largest sizes as yet adopted into the English service, and 

 a description of them will serve for that of the type generally. 



The gun on this system is raised by compressed air stored in 

 several chambers, and acting through the medium of a fluid 

 upon a recoil ram. 



On the recoil of the gun the liquid is driven from the cylinder 

 by the incoming ram into the lower parts of the air chambers, 

 so that as much as is required of the energy of recoil is stored 

 up by the compression of the air, and is used to raise the gun for 

 the next round. The gun is raised up and lowered on two 

 heavy beams pivoted to the lower carriage. Two long light 

 elevating rods, pivoted at one end to the breech of the gun, at 

 the other to the lower carriage, hold the gun in correct position 

 as it rises or falls ; the elevation is changed by moving the 

 position of the lower ends of the elevating rods. This can be 

 done when the gun is down without disturbing it, and con- 

 sequently with very little labour. The effect of the change is 

 apparent after the gun rises, when any slight correction can be 

 made if desired. Generally these mountings have been made 

 with overhead shields placed a little below the level of the top 

 of the gun pit, and entirely closing it. There is an aperture 

 through which the gun rises, but which can be closed when the 

 gun is out of action. 



In the case of the lo-inch gun the total weight of the revolving 

 mass is 80 tons. Only two men are required at the hand-wheels 

 to revolve it — in fact, it is within the power of one man to do 

 the whole work. The ordinary speed of training is 90° in 

 1 3 minute, while the time required to raise the gun to the firing 

 position is 20 seconds. The speed of rising might be consider- 

 ably increased, but, taking the weight of the mass in motion into 

 account, it does not appear to be desirable to accelerate it. 



At Maralunga, Spezia, in March of the present year, the first 

 68-ton disappearing mounting, manufactured for the Italian 

 Government, was tried with most satisfactory results. Fifteen 

 rounds were fired in all, some of them being made to give 

 greatly increased energy of recoil, with the view of proving the 

 gun and mounting. 



The gun was worked entirely by hand-power, and on land no 

 difficulty is experienced in thus dealing with it, while the 

 system possesses the advantage that it is always ready for use 

 should it be required, but no great alteration is necessary to 

 adapt the mounting for use with hydraulic power. 



In this case the water from the recoil press is driven through 

 spring-loaded valves instead of into air chambers. There is, 

 therefore, no storing up of the recoil energy, and to raise the gun 

 to the firing position, water pressure from an accumulator kept 

 charged by a steam-pumping engine in the usual way is em- 

 ployed. These guns and mountings are too large to be easily 

 covered by an overhead shield, but they are provided with 

 shields at the front and rear to protect the gun detachments. 



Another very successful mounting for land service has been 

 made for guns when the site is such that it is permissible to 

 place them en barbette. The gun is entirely above the parapet, 

 but the detachment is protected while loading and working the 

 gun by a broad sloping shield carried on the gun carriage and 

 recoiling with it. The shield is inclined so that any splinters, 

 &c., striking it, may be deflected in an upward direction. 



The carriage runs back on a long slide inclined at 5°, and at 

 the end of the recoil is caught by a spring catch, which retains it 

 in the run in position until the loading is finished. To load, 

 the gun is put at extreme elevation, so that the breech may be as 

 much under protection as possible, the charge being rammed 

 home with a hand rammer worked by rope tackle. The slide is 

 mounted on front and rear rollers, and has an actual central 

 pivot. The recoil is controlled by a single Vavasseur recoil 

 cylinder placed in the centre of the slide, and giving a constant 

 length of recoil for all charges, so that the spring catch to retain 

 the gun at extreme recoil for loading is always reached. 



To run out after loading, the spring catch is released, and the 



