j, and k, are so formed, that the jaws will be always opened by their weights, as they go in towards the cloth, and will then be closed by the excentric portions, and moved by the links 7, 7, in the manner before mentioned.

The eleventh improvement relates to an arrangement of revolving temples, by which the cloth is held and stretched out as it is made. Fig. 4, is a side view of the revolving temple. m, is a wheel, provided with a number of spikes n, which move in the slots o, o; the stems of the spikes pass through the boss of the wheel m, and rest against a roller p. Rotary motion being communicated to the wheel m, the spikes n, approach the cloth, in succession, and having penetrated it, are caused by the roller p, to move outwards, and stretch the cloth; they are afterwards withdrawn from it by the inclined surface r, against which they move. is a spike-wheel, wherein the spikes are all fixed;" but why it should be exhibited in connection with the wheel m, is not shewn in the specification, the above words being all that are used with reference to it.

The twelfth improvement is for the purpose of stopping the loom, when any of the warp-threads break, and become entangled with each other. It consists in applying to the shuttle a lever, which forms part of a cutting apparatus, and being acted on by the entangled warp-threads, cuts the shoot, and thus brings into action suitable machinery for stopping the loom when the weft is not properly supplied.

The following are the patentee's claims: First,—the mode of applying springs to the slay of a loom, and arranging the slay that it may move freely on the swords, and be acted on by such springs, as described. Second, the application of springs to connecting-rods, to give elasticity to the beat-up. Third,-the mode of stopping the beat-up of a loom, when the shuttle is not thrown across into the shuttle-box. Fourth,-the mode of stopping a loom, by combining the spring with the fork, and striking such spring with the slay, as described. Fifth, the mode of taking up the cloth, as it is produced, by the application of the wheel, described under the fifth improvement, and parts for moving the same. Sixth, the mode of giving off the

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warp, by means of an endless chain of teeth, and parts connected therewith. Seventh,-the mode of regulating the giving off of the warp, by means of the wheel mentioned under the seventh head, and parts for moving the same. Eighth, the mode of giving off the warp by means of grooved rollers. Ninth, the mode of applying a wheel, and parts connected therewith, for giving motion to the treadles. Tenth,—the mode of giving motion to temples, in addition to closing and opening them. Eleventh,-the mode of constructing revolving temples, by giving motion to the points or spikes. Twelfth,-the mode of applying apparatus, to be acted on by yarn sticking in the shed, in order to cut the shoot.-[Inrolled in the Inrolment Office, August, 1842.]

To EDMUND TUCK, of the Haymarket, in the county of Middlesex, silversmith, for certain improvements in the covering or plating, with silver, various metals and metallic alloys. [Sealed 4th June, 1842.]

THIS invention consists in the use of either of the two carbonates of ammonia, (namely, the sesquicarbonate and the bicarbonate,) as one of the ingredients in the mixtures or compounds employed for covering or plating various metals and metallic alloys with silver, by the action of electricity.

The material of which the articles usually plated with silver are composed, is either copper or its alloys, and of those alloys, that commonly called German silver is most frequently used. The plating or covering is effected by the aid of a solution, composed (according to the present invention) of the sesquicarbonate or bicarbonate of ammonia and a salt of silver; but the patentee finds it advantageous to vary the salt of silver, according to the nature of the metal or alloy to be plated; thus, for the common kinds of German silver, a mixture of a solution of bicarbonate of ammonia with sulphate of silver; and for plating on copper, or good German silver, a mixture of a solution of bicarbonate of ammonia with cyanide of silver, is preferred to be

used.

The plating mixture is prepared by dissolving one equivalent (seventy parts by weight) of bicarbonate of ammonia in distilled water; then adding thereto one equivalent (one hundred and fifty-six parts by weight) of sulphate of silver, or one equivalent (one hundred and thirty-four parts by weight) of cyanide of silver, and boiling the liquor until the salt of silver is entirely dissolved. The strength of the solution, that is, the proportion of water, must be regulated by the strength of the galvanic battery employed. The strongest solution which the patentee has had occasion to use, when coating bad German silver, was composed of half an ounce of sulphate of silver and one hundred and seven grains of bicarbonate of ammonia, dissolved in one pint of water. The battery which the patentee prefers, is a modification of "Daniell's constant battery."

The article to be plated is cleaned before submitting it to the action of the battery, by immersing it, for two or three hours, in a cold solution of carbonate of potash in water, then washing it in cold water, and afterwards dipping it into a mixture of aquafortis and water; the proper strength of which depends on the nature of the metal or alloy used in the manufacture of the article. After this it is washed and dried, and then well rubbed with rotten-stone on a rag, or piece of leather; and immediately before it is immersed in the plating liquid, it must be dipped into a solution of common salt, in which a little gum has been dissolved. The quality of the alloy of German silver may be known by its appearance when taken out of the pickle, or mixture of aquafortis and water; the best kinds having a perfectly white surface, and the inferior kinds being more or less darkly colored.

The patentee claims the use of either of the two carbonates of ammonia, namely, the sesquicarbonate, and the bicarbonate, as one of the ingredients in the mixtures or compounds employed for covering or plating with silver various metals and metallic alloys, by the action of electricity.-[Inrolled in the Rolls Chapel Office, December, 1842.]

To JOHN STEPHEN WOOLRICH, of Birmingham, in the county of Warwick, chemist, for improvements in coating with metal the surface of articles formed of metal or metallic alloys.-[Sealed 1st August, 1842.]

THESE improvements consist in giving a metallic coating to articles made of metal or metallic alloys, by means of a magnetic apparatus, used in combination with metallic solutions.

The magnetic apparatus is represented in Plate XIX., fig. 1, being a side view; fig. 2, a plan view; and fig. 3, an end view of the same. à, is a compound horse-shoe magnet, fixed upon the table b; and c, is an armature, fixed upon the shaft d, opposite the poles e, e, of the magnet. The armature is formed out of a flat bar of soft iron, and around each of its ends about fifty yards of copper wire f, g, onetenth of an inch thick, and covered with silk thread, are wound in a spiral direction; the wires are soldered together at h, and their other ends are connected to what the patentee terms a divider. It is shewn detached from the apparatus at fig. 4, and consists of a brass tube i, rivetted to a bent piece of brass j, which is attached to the armature by screws; at the other end of the tube i, is a cylinder of box-wood k, and on each end of it is a curved piece of copper, situated diametrically opposite to each other. Each of these pieces l, extends nearly half-way round the cylinder k, and the wires f, g, are attached to them; the wire f, being fastened to that piece of copper which is nearest to the magnet, and the wire g, after passing through the tube i, is fastened to the other piece. m, m, are four brass springs, secured by screws to four brass pillars n, n, fixed on the table b; these springs press upon the cylinder k, and its pieces of copper, and they are so adjusted, that while two of them are pressing upon the pieces of copper, the other two are pressing upon the surface of the cylinder k. In the lower part of each pillar a hole is drilled, and a piece of copper wire, one-tenth of an inch thick, is passed through the holes of the two pillars on each side of the

divider, and secured by binding screws; these wires are marked o, and p.

The mode of using this apparatus, for coating articles with metal, is as follows:-The article to be coated is connected with the wire o, and immersed in a suitable metallic solution, (hereafter described,) contained in an earthenware vessel; then a plate of metal, similar to the metal of which the solution is composed, is connected with the wire p, and rotary motion is communicated to the shaft d, with its armature and divider, by means of an endless band, passing round the pulley r.

The metallic solutions, employed by the patentee, are three in number, viz., the silvering liquor, the gilding liquor, and the coppering liquor, which are all produced by the aid of a fourth, termed the solvent. The solvent is made by boiling twenty-eight pounds (avoirdupois) of the pearlash of commerce with thirty pounds (avoirdupois) of water, in an iron vessel, until the pearlash is dissolved; the solution is then poured into an earthenware or other suitable vessel, and, when cold, fourteen pounds (avoirdupois) of distilled water is added thereto; after which it is saturated with sulphurous acid gas, and, having been again filtered, is ready for use.

The silvering liquor is prepared by dissolving twelve ounces (avoirdupois) of crystallized nitrate of silver in three pounds of distilled water, in an earthenware vessel, and then gradually adding the above-mentioned solvent to the solution, so long as a whitish-colored precipitate is produced. The supernatant liquor being then drawn off, the precipitate is washed in distilled water, and mixed with as much of the above solvent as will dissolve it, and one-sixth more, so that the solvent may be in excess. After this, the mixture is allowed to rest for twenty-four hours, and is then filtered.

In order to make the gilding liquor, four ounces (troy) of fine gold are dissolved in a mixture of eleven ounces of nitric acid, of specific gravity 1.45; thirteen ounces of muriatic acid, of specific gravity 1.15; and twelve ounces of distilled water; the solution is then evaporated and crys