Lieutenant Graydon's Big Gun.

Daily Telegraph (Napier), Issue 6065, 4 February 1891, Page 3

Lieutenant Graydon's Big Gun.

. « Messrs Taunton, Delmard, Lane, and Co., of Birmingham, are just finishing the largest dynamite Kirn which has yet been made. The explosive contents are made up for greater safety iv tiny waxen pellets, and iodged in a shell, the true flight of which is secured, by a tapering telescopic tail; and the. gun is to be.discharged by the expansion of condensed air at a pressure of 50001b par square inch, the impulse of which is a safer propelling energy than the ignition of any kind of powder, because it does not operate so suddenly as to cause a danger of the premature explosion of the missile. The telescopic tail enables Lieut. Graydon to shorten his shell by one-half, and to reduce proportionately the length of the impulse tube or gun proper ; while the use of a pneumatic charge makes it possible, withocit danger, to construct the shell more fiimsily than would otherwise be the case. The contract with Messrs Taunton and Co. is for a loin torpedo-projector which will thro v a charge of 6001b of dynamite a distance of three miles ; but it i-i expected that this contract will be followed h, orders for still larger weapons. As foou as the gun now in hand i.s delivered there will be a trial of its powers in Portsmouth against the Zalinski gun, not with duminy_ shells, as in the case of the American experiments, but with actual charges of dynamite The noise of the discharge being small, the projectile raij;ht be dropped into a fort or ou to a ship without giving the besieged any intimation of the quarter from which the attack came. The concussion when the dynamite exploded would in all probability be violent enough to put a large garrison hors de combat, even if they were r.ot wounded by debris; and, truly aimed, a eingle shell would destroy an ironclad. The barrel, or pneumatic tube of the gur,. is of Wbitworth forged steel, and weighs about eleven tons. It is supported at the breech end on fixed triunnious loin iv diameter, whifch are hollowed for the passage of the coir.pi-essod air. Towards the muzzle it io carriedon movable trunnions engaged with two forged stojl arni.s or levers. Thet-e levers have sliding fulurums, and are actuated by a hydraulic plunger for the purpose of elevatiug or depressing the gun The breech is closed by means of asteelscvew-block with interrupted threads, as in heavy servics ordnance. A peculiar feature of this particular Graydon gun is that it can be loaded i)t any decree of elevation within its working range. Pivotted to tho breech trunnions there is a loading slide or tray for the reception of the projectile or torpedo, the weight of which is about one ton. This elide, at all times when the barrel is elevated above the horizontal line, rises by hydraulic pressure to receive the projectile from a tram trolley. By opening a valve the slide is then made to descend with its load, and becomes lineable with the barrel of the gun. On each side of the barrel is fixed a small doubleacting hydraulic cylinder, the plungers of which noc only control the movement of the loading eljde, hut also, by their continued action, draw the projectile up into the barrel, where it is held. The breech-closing block, suspended absve the trunnions by counter-weights, theu dcs ends, ami is also drawn iuto the breech by the crosshaad of the hydraulic plungers, and locked. The gun is now ready for discharge. The compressed air reservoirs, a .complement of which numbers thirty-two, tire 4ft long and lOin in diametoi-, are made of metal fm thick, and are the invention of Mr Laiie. They are tested to a, pressure of four tons; to tho square inch. They aro carried with the gun in four sections of eight each, tvv.) on each side of the gun-carriage. Filled wi»h air compressed to 50001b. per square inch, or ab'jut l-340th of its original volume, the capacity of each at tho working pressure is 17,000 cubic feet of air, weighing llcwt in its compressed condition. Any number out of the four sections may be discharged, according to the range desired or tho weight of the projectile. The discharging yajves area peculiar urrar.gcmiril; of the pjston type, and are packed on t'ii* hydraulic system. All va'ves and piped, wore not forged, are of WhitworLh east steel. The carriage on jyhjoh the barrel is motinted_ is COii-trii.cU.-d of heavy steel plates, witii missive trunnion -hearings of cast iron, secured to it by means ;>t numerous turned bolts. The carriage is supported! oa the roller path with conical rollers geared together and. iotuaUrd by a Her.n.in and Froude spherical engine, the power of which also is air. The roller path, which will ultimately U iy.n bedded in concrete, is made in sections of east iron. If is 21ft in diameter, and i.s planed on it* surface. The air from tho compressors if passed to tho reservoirs on the gun-carriage throu"h a central piv it or Kwivel tube. The gun can be loaded, elevated, trained, and discharged by one person. With tho gun there is ot oluirfe. v special air-compressor This is 'a modification of the hL-h-pressurt machines designed by Mr H- Lane (now ]ar' r oly in use in this country, aiid adoptee by "several foreign governments) for oxygen hydrogen, and carbonic acid. The air it compressed in four operations, tho pistons decreasing in diameter at each stage. Thi first, which draws the air from the atmosphere, is 12in in diameter, and the last which delivers it to the reservoirs, is 2\\a Aftfr each operation tho air is cooled by i tubular coil, surrounded with water. The designing and construction of th< pneumatic gun has been carried out by M Lane engineer to the company, under tin supervision of the inventor, Lieutenant J W. Graydou, .of the United States Navy who has been residing in Birmingham witl that object. It is in some of the measure due to him that the apparatus for throwing highly-explosive shells considerabledistance with accuracy is at present engaging th serious attention of all the Powers. J, pneumatic gun is now being erected a Shoeburyness for trial by the British Go veirnment, and tho United States Govern ment has not only spent already a grea deal of money on this c!a,ss of weapon, bu has set aside funds for the purchase of 25 of them. Five European Governments hay sent representatives to Birmingham to se and report upon the G r aydon projecto ' during ltd construction ; aud the Chinese Japanese, and South Ar erican Govern mehts profttis themselves greatly iutercste in its sueee.sn. Post.

A PERMANENT CURE GUARANTEED. —An Eminent French Hospital Physician, thirty years a Parisian Specialist (now retired), will inform sufferers how they may cure themselves of Nervous Debility, Weak Vitality, AH Impediments to Marriage, &a., &c, without consulting a I Medical Man. Send Sixpence m Stamps ! for Sealed Treatise and tiome Cure. AdJ dress:—-Parisian Agency Co., P.O. Box j 766, Sydney

The Five O'Clock Tea is Perfection. Davidson, Irvine, and Co., agents.