1950.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



15 



blowinjj in air at the bottom, the same result may be obtained by 

 exhaustion from the top or funnel mouth, tlie outer space of which 

 must be inclosed and connected w ith some suitable exhaust appa- 

 ratus, and in which case the annular chest at the bottom will be 

 dispensed with, and free vent given for the ingress of air. 



IRON CASKS OR VESSELS. 



Solomon Isbael Da Costa, of Great St. Helens, city of London, 

 civil engineer, for '■'■ improvenientu in vessels for holilingsolidKorfuids^ 

 and in macliinerii for manufacturing siivh res.vt'Av." — Granted May 22; 

 linroUed November 21, 18+9. [Reported in the Patent Journal.'] 



This invention relates — first, to an improved mode of construct- 

 ing barrel-shaped vessels of iron, and also to machinery used in 

 the construction of such vessels. 



In the manufacture of these vessels the patentee forms the body 

 part by bending the plate or sheet iron by means of rollers, some- 

 what similar to plate- bending rollers used for boiler purposes; the 

 plate used being either such as will form either one-half of the 

 vessel, or complete the entire circle. The upper bending or 

 shaping roller, for this purpose, is formed of a barrel-shape (that 

 is, larger at the centre than at the ends), more or less, according 

 to the shape to be given to the plate, while the under roller is the 

 reverse of the upper, so as to receive it and squeeze the ])late 

 between them. On the ends of the upper roller are two cutting 

 discs, or edges, which pare the edges of the plate as it is passed 

 between the rollers. A third roller is employed to guide and give 

 the direction to the plate under operation, its proximity to and 

 position with regard to the other rollers being adjustable for the 

 purpose of bending the plate, more or less, according to the size of 

 the vessel to be made, as well understood in tlie bending of boiler 

 plates. The plate, after being heated red hot, is passed through 

 the rollers, which, at one and the same operation, bend, shape, and 

 trim the body part of the vessel. 



The plate, after being bent, encircles the upper roller; and in 

 order to remove it readily, the patentee forms one of the be.irings 

 of a spherical shape, which allocs the opposite end to be raised, 

 for the purpose of removing the bent plate. The rollers are so 

 formed as to set back a small portion of the plate at each end, so 

 as to form an enlargement for the reception of the ends of the 

 cask; the enlarged end is of a cylindrical form, or rather slightly 

 coned outwards, to render the ends more easily introduced and 

 fitted. The ends are formed of plate- iron, having an edge turned 

 up, which fits the enlarged part of the end, and is, after being 

 fitted, brazed in its place; these casks are furnished with thickness 

 rings at the bung and tap holes, such bungs being rivetted, or 

 otherwise secured, in their position. 



The annexed engraving represents in elevation a set of rollers 

 of a different construction; instead of one lower roller being em- 

 ployed, two are substituted, the third or bending roller being the 

 same as before described, but which is not shown in the engraving; 

 these three rollers are geared together in such manner as to pro- 

 duce a like motion of their periplieries, or, as near as possible, 

 taking the medium of their diameter. The cutters are here repre- 

 sented at either end of the upper roller, but the portion wliich is 

 set back to form the enlargement of the end is omitted. The 

 superfluous metal is cut off by the cutters passing or crossing the 

 ends of the upper rollers. The action of these rollers will be 

 sufficiently understood without further description. A third ma- 

 chine for this purpose consists of two blocks, having semicircular 



cavities, opposed to each other, and which are drawn together or 

 expanded by means of right and left hand screws, on a shaft; the 

 plate having been partially bent, is introduced between the two 

 blocks, and by drawing them together, completes nearly the entire 

 circle. The hollows or cavities of these blocks are of the same 

 barrel form, and in order to press the bent plate into which, the 

 patentee employs a shaft, concentric with the hollow blocks, cariy- 

 ing between two crank-arms and a barrel-shaped roller; after the 

 plate has been partially formed, the shaft is caused to rotate, by 

 which the roller will be pressed and rolled round the interior sur- 

 face of the vessel under formation, causing it to be compressed 

 into the form or cavity in the blocks. The plate, while under 

 operation, is made red hot as before. 



The second part has reference to the manufacture of such 

 articles as are usually struck or stamped in metal, for which purpose 

 the patentee em])loys a press very similar to the (udinary screw- 

 press, with dies — that is, male and female of the ordinary kind. 

 But instead of using sheets or plates of metal, the patentee uses 

 the metal in a molten or semi-molten state, which is deposited in 

 the bottom of the female die, in sufheient quantity to produce the 

 article required. The upper die is then brought down while the 

 metal is still soft or in a molten state, by which it is caused to rise 

 up and fill the space between the dies; a second depression of the 

 up|ier die further imparting the impression to be imparted to the 

 urticle. M'here the impression is required to be sharper tlian can 

 be obtained by this means, such articles may be again struck in the 

 ordinary manner, by which much finer and sharper lines may be 

 obtained, and with much less work than heretofore. 



The third part refers to the manufacture of hollow-formed 

 vessels in clay, cement, or other plastic material, which is some- 

 what similar to the foregoing mode of stamping metals, the object 

 being to prevent the formation of bubbles or honeycomb in the 

 articles so manufactured. The clay or other ]ilast;c material is 

 placed in the bottom of the hollow mould, which, as in the last 

 case, rises wlien the plunger or die is depressed, so as to fill the 

 space for its reception, and give the required form to the article to 

 be produced, and by which all bubbles or imperfections resulting 

 from the confinement of air in the moulds are avoided. 



The patentee claims : First — The improved vessel or cask, 

 manufactured in the manner described; and also the machinery or 

 ap])aratus for making the same. 



Secondly — The mode of pressing up in moulds or dies, vessels 

 or hollow forms, made in molten or semi-molten metal of any kind 

 suitable for the purpose, so as to produce wholly or in part the 

 shape required, and which shape may be again struck in another 

 die or dies in the ordinary manner of striking up hollow metal 

 goods, by which means a still sharper outline or finer impression 

 may be obtained. 



Thirdly — The method of making vessels or shapes of hollow 

 forms in clay, cement, or other plastic material suitable for such 

 hollow forms, and pressed upwards from below, which will prevent 

 in a great measure the formation of air bubbles, such bubbles pro- 

 ducing the vessel of a honeycomb and defective character; which 

 mode of manufacture does not require the centre disc die, which 

 in certain articles is necessary, and is usually placed at the bottom, 

 and held by one or more cross-pieces, which separate the plastic 

 form as it passes through, as for instance, in clay pipes. 



ELASTICITY OF VAPOURS. 



Sir — In reprinting, in your Journal for December, the principal 

 portions of my paper on the Elasticity of Vapours (originally pub- 

 lished in the Edinburgh New Pliilosuphical Jvvrnal for July), I ob- 

 serve that the co-etficients of the formula for calculating the 

 elasticity of the vapour of mercury have been omitted. 



As that formula is of considerable utility in delicate observations 

 of the elasticity of other va|)ours, 1 annex the co-efficients, in case 

 you may wish to publish them. 



The formula being Log P = a ■ 



r 



a for millimetres of mercury ^ 



„ for English inches of mercury = 



Log 'ii for the centigrade scale = 



,, for Fahrenheit's scale =: 



7-5305 

 fi-1259 

 3-t(irt55n 

 3-723S23G 



I am, &c. 

 Edinburgh, Dec. 10, 1849. W. 



J. Macqiorn Raxkine. 



