better, entirely dissolved, and decanted from any rema ning insoluble matters, is placed into suitable close vessels, and a current of carbonic acid gas, generated by any suitable process, is made to pass into the liquid. A carbonate of the base of the sulphuret employed precipitates, and sulphuretted hydrogen is evolved, which, on being conducted through appropriate apparatus, is either ignited in contact with just sufficient atmospheric air to convert its hydrogen into water (proper precautions being taken to prevent explosion), or the sulphuretted hydrogen is brought into contact with nitrous acid vapours and an excess of atmospheric air. Whichever of these methods be adopted, sulphur will be set free, and deposited by conducting the gases or vapours through suitably-arranged chambers. When it is desired to obtain sulphuric acid, the sulphuretted hydrogen is ignited in an excess of atmospheric air, and is thus converted to sulphurous acid vapours, which are then conducted into apparatus such as usually employed in the manufacture of sulphuric acid, and treated therein in the manner ordinarily adopted in such cases. When the decomposition is completed (which is indicated by the evolution of sulphuretted hydrogen gas ceasing, or by testing the liquid in the decomposing vessel with lead paper, which should not change colour), the liquid is drawn off, and the carbonate withdrawn. To obtain the oxides of barytes and strontia, the carbonates of these bases are subjected to intense heat in a suitable furnace until the entire evolution of their carbonic acid takes place, which will be materially assisted by the injection of steam; by which a hydrated oxide will be produced. Or if, when making the solution of the sulphuret of strontia or barytes, the same be in a boiling state and highly concentrated, and then allowed to cool, almost half of the base will be crystallized in the form of hydrated oxide, and a hydrosulphated sulphuret will remain in solution; this, on being evaporated in close vessels after separation from the crystals, will part with its sulphuretted hydrogen, and a small portion of sulphur will be sublimed. The escaping gas (the watery vapour being first condensed) can be treated and converted into sulphuric acid, as before mentioned. A simple sulphuret of the base employed will remain in the vessel, which, on being re-dissolved, may be passed repeatedly through the same process as above, until the whole of the oxide and sulphate of the base have been obtained; the hydrated crystals can then be purified from the portion of sulphuret adhering to them by washing or re-crystallization, and can then, if thought proper, be converted to carbonate by exposure, in a moist state, to carbonic acid, or by passing a current of that gas into a solution made of the crystals in water. To produce carbonate of soda or potassa, the sulphates of these bases in solution at the ordinary temperature, are brought into contact with the carbonate of barytes, when mutual decomposition takes place, which is greatly accelerated and perfected by passing a current of carbonic acid into the mixture. By this process, sulphate of barytes is formed, and carbonate of soda and potassa remain in solution, and may be obtained by crystallization, or by evaporating the solution to dryness. To obtain hydrated oxides, or caustic soda, or potassa, the oxides of barytes or strontia (the latter being much more readily reducible from the carbonate, is preferable) are slacked with water into a thin paste, to which a proportionate solution of sulphate of soda or potassa is added, when sulphate of barytes or strontia precipitates, and the caustic soda or potassa remains in solution, and may be decanted and used in that state, or evaporated to dryness, and converted to a hydrated oxide by melting it at a lowered temperature. The carbonate of strontia may be also used to decompose the sulphate of soda or potassa, in conjunction with carbonic acid; but this material is very inferior to baryta for the purpose, as, without the aid of carbonic acid, no decomposing effect would be produced. Claims.-1. The combined process of manufacturing sulphur or sulphuric acid, carbonates of barytes and strontia, and their oxides, from the sulphates of these bases, by the before-described methods. 2. The making of carbonates of strontia and barytes and their oxides from the sulphates of these bases by the methods described. 3. The producing of sulphur or sulphuric acid from sulpbates of barytes or strontia by the method above mentioned. 4. The manufacture or improvement in the process of producing carbonates of soda and potassa, by treating or decomposing the sulphates of these bases by the carbonates of barytes or strontia, employing in aid thereof a current or sufficient quantity of carbonic acid, as described; the use of carbonic acid being optional with baryta, but imperative with scrontia. The patentee does not claim the production of the oxides of barytes or strontia by the calcination of the carbonates of these bases, when the carbonates are produced or obtained in any other than the method or manner before described. HERBERT MINTON, of Hart's-hill, gen tleman, and AUGUSTUS JOHN HOFFSTAEDT, of Bridge street, Blackfriars, gentleman. For improvements in the manufacture of faces or dials for clocks, watches, barometers, gas meters, and mariners' compasses, or other articles requiring such faces or dials. (Partly a communication.) Patent dated March 17, 1851. This invention consists in the substitution of porcelain or earthenware for the wood or metal and enamel, employed in the manufacture of faces or dials for watches, clocks, and other articles requiring such faces or dials. In carrying their invention into effect, the patentees either press clay or other suitable plastic material into moulds of the required shape, or they throw the faces on the wheel, and afterwards turn them down to the proper form, after which they are passed through the usual firing processes, and subsequently the devices or figures are printed on the biscuit in the manner adopted when ornamenting articles of earthenware, or painted by hand after the glazing, and passed through the enamelling kiln in order to cause the colours to adhere. Or the faces may be manufactured from powdered clay by pressure, and subsequently have the required devices or figures printed or painted thereon as above described. These devices may be also obtained on the faces or dials according to the methods practised when manufacturing encaustic tiles, is which hollows corresponding to the figures are formed and subsequently filled in with coloured clay in the state of paste or in strips. Faces manufactured in this manner do not require glazing, but they may be subjected to that operation, by which the brilliancy of the colours employed in producing the figures or devices thereon will be much in reased. Claims.-1. Manufacturing faces or dials of plastic clay or other analogous plastic material, having devices or figures thereon, suitable for the purposes to which they may be applied. 2. Manufacturing faces or dials for watches, clocks, and other articles requiring such faces or dials, from powdered clay, or other analogous compound, by pressure, and applying the requisite devices thereto by any of the well-known printing or painting processes 3. The application of the process now employed in the manufacture of encaustic tiles to the manufacture of faces or dials for watches, clocks, and other articles to which faces or dials may be applied. JAMES HART, of Seymour-place. For improvements in the manufacture of bricks, tiles, and other articles made from plastic materials, and in the means of making parts of the machinery used therein. Patent dated March 17, 1851. Under the first head of his invention, which consists mainly of improvements on a machine which formed the subject of a patent granted to Mr. Hart in 1848, the patentee claims: 1. The making of the moulds used in this machine larger at the bottom than at the top, or part where the clay or plastic material is forced in, so as to insure uniformity of substance and form after the shrinkage caused by baking. 2. The application of a flange projecting from the top sides of the ends of the moulds to facilitate the removal of the mould and brick contained therein from the machine. 3. The application of additional stops to the endless chains (which form the bottoms of the moulds) to prevent the moulds from slipping during the moulding; and the employment of suitable means to retain the chain of plates in position during the same operation. 4. The arranging of the hexagonal or chain wheels, so that one or more of them shall revolve freely on their axes. 5. The application of projections to pugmills for guiding the moulds as they enter the machine. 6. The supporting of the road or way over which the moulds travel on a seating resting on springs adjustable to suit the thickness of the moulds and the pressure to be sustained by them. 7. The employment of clutch-boxes to throw the chain into and out of action, and for starting and stopping the machine. 8. An arrangement of wheels for giving motion to the chain of plates which form the bottom of the moulds. 9. The employment of revolving scrapers and apparatus working therewith to remove the superfluous plastic material. 10. The application of stuffing-boxes to the shafts which pass through the sides of the pug-mill, and the application of a dividing-plate, or partition, in pug-mills between the two rows of moulds, and the flanges on the moulds, in order to keep the material in its proper position. 11. An improved door to the sand barrel, and an additional riddle or sieve for distributing the sand more evenly over the surface of the moulds. 12. The application of leather or other packing to the road wheel-shaft to prevent injury to the machinery when travelling. 13. A mode of applying or connecting shafts to the machine, so that they may be readily applied or removed. 14. The application of a screw or screws to move a piston or pistons for the purpose of forcing clay or other plastic material through moulding orifices. 15. Causing the crushing rollers to move with different surface speeds. 16. The employment of ground coal or cinder instead of sifted ashes as now usually employed in the manufacture of bricks. The second head of the invention relates to a drilling machine for boring holes in the ends of the moulds and plates which form the revolving chain, in which two drills, acting simultaneously on the opposite ends of the plate or mould, and caused to approach each gradually as the operation of boring progresses, are employed. ALEXANDER ROBERTSON, of Holloway, engineer, and JAMES GLOVER, of the same place. For improvements in the rolling and laminating of metals, and in the manufacture of metallic cases and coverings. Patent dated March 20, 1851. The object of the improvements specified under the first head of this invention is to produce as may be required a uniform elastic pressure, or a uniform dead pressure on both ends of the rolls employed for rolling and laminating metals. For this purpose a crosshead of the same length as the rolls, and capable of sliding up and down immediately over them, is mounted in the same frame, and to each end of this crosshead is attached by keys a rod or plunger, which bears against the brasses fixed at the ends of the rolls. The centre of the crosshead is hollowed out of a cylindrical form, and a coiled spring is inserted and inclosed by a plain disc of metal. A nut is tapped through the centre of the bridge-piece at the top of the frame, in which works a screw turned by a hand. wheel, and bearing upon the disc over the spring in the centre of the crosshead. By turning the band-wheel, the screw may be lowered, and the crosshead and rods attached thereto caused to descend and act on the rolls so as to produce a uniform elastic pressure at both ends, which may be increased to any desired extent by lowering the screw. When a dead pressure is required the spring in the crosshead is dispensed with, and the screw made to act against a solid abutment. Another method of producing an elastic pressure on the rolls is by the application of hydraulic power, and in this case the cylinder in the crosshead is to be connected with a force-pump, and the pressure produced in the ordinary The method of making boxes or coverings Claims.-1. The producing a uniform elastic pressure on each end of the rolls in the rolling and laminating of metal. 2. The producing a uniform dead pressure on each end of the rolls in the rolling and laminating of metals, by means of the arrangements described. 3. The manufacture of William Betts's patent metal in the manner described. 4. The manufacture of metallic coverings made wholly or partly of tinfoil, or of William Betts's patent metal, pasted or glued on paper, and embossed, painted, or otherwise ornamented, as described. WEEKLY LIST OF NEW ENGLISH PATENTS. Frederick Hale Thomson, of Berner's-street, Middlesex, gentleman, and George Foord, of Wardour-street, in the same county, chemist, for improvements in bending and annealing glass. September 25; six months. Charles Green, of Birmingham, Warwick, for improvements in the manufacture of brass tubes. September 25; six months. Richard Archibald Brooman, of the firm of J. C. Robertson and Co., of Fleet-street, London, patent agents, for improvements in presses and in pressing. (Being a communication.) September 25; six months. Robert Roberts, of Dolgelly, Merioneth, mine agent, for an improved method of quarrying certain substances. September 25, six months. Charles Watt, of Kennington, Surrey, chemist, for improvements in the decomposing of saline and other substances, and in separating their compo nent parts, or some of them, from each other; also in the forming of certain compounds or combinations of substances, and also in the separating of metals from each other, and in freeing them from impurities. September 25; six months. James Garforth, of Dukinfield, Chester, engineer, for certain improvements in locomotive steam engines. September 25; six months. David Stephens Brown, of the Old Kent-road, Surrey, gentleman, for an improved agricultural implement. September 25; six months. Ernst Kaemmerer, of Blomberg, in the kingdom of Prussia, iron-founder, for his invention of improvements in sowing, depositing, or distributing seeds over land. September 25; six months. WEEKLY LIST OF DESIGNS FOR ARTICLES OF UTILITY REGISTERED. Date of Registra- the Re tion. gister. Proprietors' Names. Henry S. Rogers......... New Oxford-street.................. Eye renovator. and T. A. Sorby Sheffield.......... R. Sorby, R. Sorby, jun., Point for scythes. and T. A. Sorby ...... Sheffield................................. Point for a reaping-hook. W. Scott..................... Exeter The Grangemouth Coal Company 2951 T. Cook " 2952 Robert Hammond James Guest....... The Rev. E. H. John Air-regulator, with air-strainer for the admission of pure air into apartments without a draught. Alarum for houses. Kirkgate, York.............................................................. General two horse reaping Birmingham... Grangemouth, Falkirk ............ Drain-pipe, chair, and sleeper. Lindfield, Sussex..................... Skim plough. Beach and Minte......... Birmingham.... WEEKLY LIST OF PROVISIONAL REGISTRATIONS. Henry Maling............... Home-office, Whitehall............ Elevation sight for rifles. Wendling, Norfolk .................. Economic heating apparatus Ebenezer Poulson, sen... Monkswearmouth, Sunderland.. Life-boat. Camberwell LONDON: Edited, Printed, and Published by Joseph Clinton Robertson, of No. 166, Fleet-street, in the City of London- Sold by A. and W. Galignani, Rue Vivienne, Patis; Machin and Co., Dublin; W. C. Campbell and Co., Hamburg. |