Aug. 16.] THE NEW ZEALAND GAZETTE. 1563

No. 12830.—2nd August, 1900.—THE GENERAL METAL REDUCTION COMPANY, LIMITED, of 85, Gracechurch Street, London, England (assignees of Guy de Bechi, of 85, Gracechurch Street, London, aforesaid, Chemical Engineer). Improvements in and relating to the treatment of complex ores containing zinc and lead.

Claims.—(1.) A process for the treatment of complex ores containing zinc and lead for the recovery of metals therefrom, which consists in mixing the said ore with a chloride salt of an alkali metal, or with a chloride salt of an alkaline-earth metal, and subjecting this mixture to a combined roasting and smelting operation, substantially as and for the purpose specified. (2.) The treatment of complex ores containing zinc and lead for the recovery of metals therefrom, substantially as and for the purpose specified.
(Specification, 2s. 3d.)

No. 12831.—2nd August, 1900.—THE GENERAL METAL REDUCTION COMPANY, LIMITED, of 85, Gracechurch Street, London, England (assignees of Guy de Bechi, of 85, Gracechurch Street, London, aforesaid, Chemical Engineer). Improvements in and relating to the production of zinc-oxide for the manufacture of spelter.

Claims.—(1.) The method of treating precipitated hydrated oxide of zinc consisting in heating it to a bright-red heat in the pressure of air, and then compressing the calcined residue with or without the previous addition to the said residue of carbon and a binding agent, substantially as and for the purpose specified. (2.) The method of treating hydrated oxide of zinc substantially as described, for the purposes specified.
(Specification, 2s. 9d.)

No. 12832.—2nd August, 1900.—WILLIAM LAWRENCE VOELKER, of 42, Bernard Street, Russell Square, London, England, Electrician. Improvements in the manufacture of incandescent electric lamps.

Claims.—(1.) The described method of manufacturing incandescent electric lamps, consisting in forming a bulbous body with two extensions which project in the same direction and have an air-space between them, then introducing a loop-shaped filament, so that the legs thereof respectively occupy the said extensions and are sealed therein, and finally closing the bulbous part of the chamber and exhausting the same. (2.) An electric incandescent lamp, comprising a vacuous chamber embracing the bend of the filament, and formed with two extensions which project in the same direction and have an air-space between them, each extension enclosing a leg of the filament, and having its extremity separately mounted in a socket common to both extensions. (3.) For use in mounting a filament in an electric-lamp chamber of the character described, a U-shaped carrier formed with laterally turned extremities, wherein are fixed the leading-in wires, substantially as set forth.
(Specification, 3s. 3d.; drawings, 3s.)

No. 12833.—2nd August, 1900.—WILLIAM LAWRENCE VOELKER, of 42, Bernard Street, Russell Square, London, England, Electrician. Improvements in the manufacture of filaments for incandescent electric lamps, and in means applicable for use in such manufacture.

Claims.—(1.) In the manufacture of incandescent-electric-lamp filaments, the described method of producing carbides of the metals, consisting in taking two parts by weight of chemically pure nitrate of the metal, and one part by weight of pure cane sugar, dissolving the same in a minimum quantity of distilled water, and heating the solution in a suitable evaporating-dish to boiling-point, then withdrawing the source of heat, and allowing the mass to assume the condition at which spontaneous combustion takes place, and then, the evolution of nitrous fumes having ceased, and the resulting black, porous mass having cooled, compressing the same into cakes of a size to fit the hearth of an electric furnace, and there reducing the same to a molten fluid by a large volume of current at a relatively low pressure, substantially as set forth. (2.) The described method of producing carbide filaments for incandescent electric lamps, consisting in reducing to impalpable powder the carbide of the metal or metals employed, by grinding same in a suitable mill, under benzole or naphtha, between grinding-surfaces of the like carbide, separating the powder from the benzole or naphtha, mixing the former with a viscous compound of gun-cotton and oil of cassia, rolling the mass between hard polished rollers, squirting the same through jewel dies, dry-
ing the filaments so formed, heating the latter to a bright-red colour by means of an electric current of high voltage, in an atmosphere of a purified and attenuated gas, then volatilising at a very high temperature and in vacuo the surface carbon deposited from the gas, and finally completing the union of any uncombined carbon with the carbide in the core of the filaments by bringing them to their highest degree of incandescence, substantially as set forth. (3.) In the manufacture of incandescent filaments from carbides of metals, the employment of grinding-surfaces composed of the same carbide as that in course of being ground, the material treated being meanwhile covered with benzol, naphtha, or like fluid hydrocarbon, deterioration by contamination with impurities and by oxidation being thereby prevented. (4.) In the manufacture of filaments for incandescent electric lamps from carbide of titanium, the described means for varying the colour of the light emitted by the filament; same consisting in adding to the titanium-nitrate and cane-sugar solution a suitable proportion of uranium-nitrate, or uranium-nitrate in conjunction with thorium-nitrate, the mass being ultimately reduced in the electric furnace, substantially as set forth. (5.) In the manufacture of incandescent-electric-lamp filaments from carbide or carbides of metal or metals, electrically heating an unbaked carbon filament prepared from pure powdered carbon and a suitable binding mixture in a vapour of the metal desired to form the base of the carbide, substantially as set forth. (6.) An electric furnace whereof the parts exposed to the direct action of the heat are composed of the oxide or oxides which, by means of the electric current, is or are to be decomposed, substantially as and for the purpose set forth. (7.) Filaments for incandescent electric lamps, composed of a carbide of a metal or of metals, and produced substantially as described.
(Specification, 11s. 6d.; drawings, 10s. 6d.)

No. 12834.—2nd August, 1900.—CHARLES CLAMOND, of 15 Rue Picot, Paris, France, Engineer. Improvements in gas stoves.

Claims.—(1.) In gas stoves, effecting the combustion of the fuel within refractory tubes pierced with small holes, substantially as described. (2.) In a gas stove of the type referred to in the first claim, the arrangement of the tubes in the manner shown in Fig. 3 and Fig. 5 so as to prevent smell. (3.) In gas stoves of the type referred to in the first claim, the use of the devices described for the purpose of rendering the supply of the gaseous mixture equal throughout the apparatus. (4.) In gas stoves of the type referred to in the first claim, the use of the burners set forth. (5.) The gas stoves described and shown in the drawings.
(Specification, 6s. 3d.; drawings, 13s.)

No. 12836.—2nd August, 1900.—WILLIAM KINGSLAND, of 8, Bream’s Buildings, Chancery Lane, London, England, Electrical Engineer. A new or improved method of and devices for regulating or controlling electrical switches.

Extract from Specification.—In electrical switches which are employed to connect and disconnect an electrical circuit, and are operated by means of a tappet action, it may, and frequently does, happen that the moving part or parts of the switch acquire, as the result of such tappet action, greater momentum than is necessary to carry out the required amount of movement of the switch; and that amount of the momentum which is unrequired to effect the requisite change in position of the switch is detrimental, in that it may carry the moving part of the switch beyond the position which it is desired it should assume, or cause injury to the switch-mechanism, and the objects of my present invention are to devise a method of and provide means for overcoming these disadvantages. With these objects in view, I provide mechanism, as described, to regulate and control the motion of a rotative shaft by which the switch is operated, the rotative shaft receiving its motion by the impact of a moving tappet bar or bars. Such regulating and controlling mechanisms I so arrange or construct that the switch-shaft during its motion is subjected to a frictional braking action, while the braking-mechanism is so fitted that the impact of the tappet is taken up by springs or equivalent devices, which latter are also arranged so as to effect the return of the moving part or parts to the position it or they should be caused to assume in cases where the said part or parts are carried by the impact beyond such required positions, such return or adjustment being effected by the resilient or other accumulated power. In some cases, instead of, or in addition to, the mechanism being fitted to permit of a resilient or yielding motion to the action of the tappet, and a return motion by the power so stored up, I so arrange and construct same that a braking action is produced, combined with a stop action, which takes