1847.] 



THE CIVIL ENGINEER AND ARCHITECTS JOURNAL. 



179 



pensating elasticity of siioli springs. The shaft, A, is connpcted or 

 coupled at c, to the sliaft, c, which carries the propelling-blade, D, 

 formed as a cylindrical axis, which passes through the shaft, c, and 

 the boss, E, where it is held by means of the cotter, e. The colter is 

 cut or split in a ditferent direction to that generally practised. This 

 form of cotter is fixed by opening the slit by a drift or wedge, and, 

 wliile open, rivetting in 'the small bolt, which leaves the cotter per- 

 fectly secure and safe. Tlie bladi', D, tl)us supported on the shaft, C, 

 part'ikes of the revolution of such shaft at the same time that it is 

 free and at liberty to move on its own axis ; so that, supposing the 

 shaft, c, to revolve in the direction indicated by the arrows, the re- 

 sistance of the water will place the blade, D, in the position lepre- 

 sented, resting against the shoulder or fice, f, formed in the buss, E, 

 as seen at fig. '2 ; but when the revolution of the shaft, C, is reversed, 

 the blade will vibrate on its axis from the same resistance of the 

 water, and assume the opposite position, resting on the shoulder or 

 face, g. The angles formed by the slioulders,/and g, with the shaft, c, 

 are slightly varied, so that the angle formed by the shoulder, g, being 

 more acute, will drive quicker when required, without any increase 

 of speed in the rotation of the shaft, c. By this arrangement the 

 blade, D, having free play on its axis between the shoulders, / and g, 

 will at all times yield to any adverse pressure which may arise from 

 the superior velocity of the vessel to that generated by the propulsion 

 of the blade, D, itself ; so that, supposing sail to be on the vessel at 

 the same time that the propeller is in action, and that the gale should 

 suddenly carry the vessel beyond the speed due to the propeller, it 

 will instantly yield to the adverse pressure, a>id present no resistance 

 to the course of the vessel. And in like manner, when the vessel is 

 under sail, and no rotation is imparted to the shaft, C, the blade, D, 

 will yield to the adverse pressure of the water, and assume that po- 

 sition which prevents the least resistance to the onward course of the 

 vessel. The shaft, c, is supported in a hollow tube, x, x, passing 

 through, and firmly fixed in, the dead wood of the vessel's stern, and 

 lubricated at various points by means of pipes, marked F, carried to 

 such an elevation as to support a column of oil sutBcient to overcome 

 the pressure of the external water, and ensure the necessary supply of 

 oil where required, which is not always the case in the ordinary ar- 

 rangements of machinery of this nature. It will be also seen, in this 

 figure, that the furce or pressure imjiarted from the rotation ot the 

 blade, D, to the vessel, is received from the boss, e, resting and re- 

 volving against the fixed tube, x, x, which carries the shaft, C, at a 

 point immersed in the external water, which prevents it heating 

 whilst the superior column of od, supplied by the small lube, F, lubri- 

 cates the parts in contact. Tlie shaft, C, is formed of two seuii- 

 cylindrical halves, the centre or flat surface of each being planed or 

 ploughed out, so that when placed face to face, they form a cylindri- 

 cal, hollow shaft, through which is passed a rod or bolt, o, for the 

 purpose of fixing or bolting the blade, D, when in a propelling posi- 

 tion, which bolting or fixing is practised only when backing or stern- 

 way is required. The bolt, or rod, o, is traversed by the lever, G, 

 and may be put into action, or relieved at any moment, while the 

 blade, D, is resting on either one or other ot the shoulders, /, or g. 

 holes being provided in the cylindrical axis of the blade, D, in the 

 proper position to receive the bolt, o, and when bolted, the reverse 

 rotation of the shaft, G, necessarily backs the vessel. 



GUTTA PERCHA SAFETY FUZE. 



George Smith, of Camborne, Cornwall, safet\ -fuze manufacturer, 

 for " ImprovtmetUs in tht manujaclure of saftlyjusts." Granted 

 November 12, 18-16; Enrolled May 8, 1S47. (Reported in the 

 Mtchanici' Magazine.) 



The safety fuze is to be made in such manner and material, to ren- 

 der them less liable to injury from changes of atmos|iheric tempera- 

 ture, damp, or the action and pressure of water, when employed in 

 subiuarine operations, by employing gutta percha to enclose an inte- 

 rior cylinder of genpowder ; or as a coating, or covering, for the or- 

 dinary hempen fuzes. The cylinder for gunpowder is made with 

 gutta percha in the following manner: — A cylinder of iron, capable of 

 supporting a pressure of 5UU lb. to the square inch, and made at its 

 lower extremity of the form of an inverted cone, is surrounded with 

 a casing, between which and tlie cylinder steam is allowed to circu- 

 late. The lower part of the cylinder — that is, the apex of the in- 

 verted cone — terminates in a pipe, which is carried down through a 

 cistern of cold water. A gunpowder chamber, or funnel, is supported 

 by suitable bearings in the centre of the cylinder, and, passing through 

 the inverted cone, terminates in the pipe below the joint. The funnel 

 is filled with gunpowder, having a thread through the centre thereof, 

 to facilitate its passage; an J the cylinder with gutta percha. The 



steam is made to circulate between the cylinder and outside casing, 

 until the gutta percha assumes the consistency of putty. It is then 

 pressed through the pipe, and, passing round the gunpowder funnel, 

 takes the form of a hollow tube, while it becomes filled with gunpow- 

 der. The fuze, in passing through the cold water cistern, acquires a 

 degree of firmness, which may be increased by causing it to pass be- 

 tween two rollers, grooved on their peripheries, and made to revolve 

 in opposite directions. The ordinary hempen fuzes are also coated 

 with gutta percha in the following manner: — An iron cylinder, simi- 

 lar to the preceding, and heated in like manner, is filled witli gutta 

 percha, %vhich is subjected to the pressure of about 300 lb. to the 

 square inch. The sides of the cylinders are bored with holes of dif- 

 ferent diameters, to suit the size of different fuzes, to wdiich inlet and 

 corresponding outlet pipes are attached. When the gutta percha is 

 sufficiently softened, a wire, hooked at the end, is made to enter one 

 of the inlet pipes, and, passing through the mass of gutta percha, to 

 come out at the exit one opposite. The fuze is cooled in its passage 

 through the exit pipe by an arrangement similar to the one described. 



SHIPS' ANCHORS AND MASTS. 



John James Alexander Maccarthy, of Sidney Terrace, Bromp- 

 ton, gentleman, for " Imjjioremeiits in anchors, and Jids for masts for 

 vessels." Granted Oct. •22nd, 1846 ; Enrolled April 22nd, 1847. 



The improvements relate, firstly, to an improved form of anchor 

 for ships, as shown in the annexed engraving. It is made with only 

 one fluke, and a stem or shank of the form shown iu the engraving, 



in order that the centre of gravity of the mass shall be as near as 

 possible to a line drawn from the point of the fluke to that part of the 

 shank where the stock is attached. The stock is of a heart shape, 

 made of iron, welded to the shank, or it may be formed separately, 

 and secured by any suitable means. This stock is constructed with 

 the greatest proportion of metal nearest tlie shank, to render it 

 stronger, and more capable of resisting the shocks and strains it may 

 be subjected to, and, at the same time, it keeps the greater proportion 

 of the weight near the desired point. If an anchor be constructed as 

 described, whicliever way it may fall, it will, by its own gravity, take 

 the position shown in the engraving. 



The second part of the improvements consists in introducing a 

 ratchet and pall for supporting the top-masts of vessels ; the ratchet, 

 being secured to the top-mast, and the pall hinged to the lower mast, 

 the mast is raised and lowered in the usual way by a pulley let into 

 the lower end thereof, the mast as usual passing through holes in the 

 cap and cross-tree ; when it is desired to lower the mast, the pall is 

 withdrawn from the ratchet, by means of a cord or rope fastened to 

 the back of the pall, and passes over a pulley in the mast down to 

 the deck. In raising the mast, the rope is slacked ; the pall, falling 

 by its own gravity against the top-mast, enters the teeth of the rat- 

 chet on the mast's attaining the requisite height, and securely holds 

 it in the required position till again released by removi.ig the pall as 

 before described. Another improvement consists in using a hoop, 

 supported from the cross-tree by staples or hinges, iu such a maimer 

 that it may be drawn towards the lower mast and from under the 

 upper mast by a chain, the same being lowered by the pulley as usual. 

 When the mast is raised, the chain is slacked, and the hoop or fid 

 falling by its own gravity in a perpendicular position, receives the 

 weight of the mast, and in order to retain it in a proper position, that 

 part of the end of the mast which rests on the fill is cut somewhat 

 shorter, the fid being drawn by the chain against the shoulder thus 

 formed, and retains it securely in the desired position. 



IRON TUBING. 



James Roose, of Darlaston, in the county of StaiTord, tube manu- 

 facturer, for " Certain impronments in wMtd iron tubing." Granted 

 August 29, 1846 ; Enrolled February 27, 1847. 



The improvements consist, first, in taking a strip of iron of a re- 

 quired length, breadth, and tluckness, according to the size of tube, 

 and bevilling or chamfering the two edges of the lap joint, as is well 

 understood amongst tube manufacturers ; then turning the two sides 



