by means of an apparatus of the form ordinarily used for distilling alcohol (an oblong chamber divided by horizontal diaphragms, with valves opening upwards, &c.)

The claim is to the application of any apparatus whose construction and use are such as to cause, by means of diaphragms, liquid containing ammonia in a volatile state, and steam, to pass in mutual contact and in opposite directions, whereby a given quantity of heat is made to liberate ammonia from successive portions of ammoniacal liquor.

WILLIAM HENRY FOX TALBOT, OF LAYCOCK ABBEY, WILTS, ESQ., for improvements in coating or covering metals with other metals, and in colouring metallic surfaces.-Enrolment Office, June 9, 1842.

These improvements are four in number: The first consists in adding gallic acid to the metallic solutions intended to be precipitated. Any convenient solution of silver, gold, or platina is taken; and to each of them is added a solution of gallic acid in water, ether or alcohol (the last being preferred). Into any one of these mixtures a clean bright plate of metal is immersed until it becomes coated with silver, gold or platina, as the case may be. A weak or dilute solution is recommended to commence with, and afterwards a stronger one. The acid need not be pure.

The second is a method of silvering metallic surfaces. Freshly precipitated chloride of silver is dissolved in hyposulphite of soda or any other liquid hyposulphite. Into this solution a clean bright plate of metal is immersed, and becomes very quickly coated with bright silver coating. To obtain thicker coats of metal, a galvanic battery is employed, using one of the liquids before described, and taking for one of the poles a piece of metal of the same kind as that intended to be precipitated.

The third is a method of ornamenting surfaces of brass or copper by first gilding them partially, according to some pattern, and then washing them over with a solution of chloride of platina, which gives a dead black appearance to the rest of the surface, and enhances the brilliancy of the parts gilt.

The fourth is a method of colouring polished surfaces of copper by exposing them to the vapour of sulphuretted hydrogen, or of any of the liquid hydrosulphurets, or to the vapours of sulphur, iodine, bromine, or chlorine, or by dipping the metal into liquids containing them.

The claim is to the use of gallic acid, or any liquid containing it, or any analogous vegetable substance for facilitating the precipitation of metals upon other metallic sur

faces, and coating them therewith-to the use of hyposulphite of soda for the silvering of metals and the employing a galvanic battery for obtaining thicker deposits of silver, gold or platina, but only when used in conjunction with one of the liquids before described -and to the colouring of copper surfaces by exposing them to the chemical action of the above-named substances.

JOSIAH TAYLOR, of Birmingham, BRASS FOUNDER, for improvements in the construction of lamps.-Enrolment Office, June 9, 1842.

These improvements relate solely to lamps for burning wax, tallow, or other fatty matter. The improved construction consists in having a vessel to contain the substance to be burned, and a chamber beneath it, for holding hot water, or hot metal to liquidate that substance. As the hot water, or metal is only required to melt the tallow or other fatty substance in the first instance, the tube which supplies the inner part of the wick with air, is furnished with two projections at top, which turn into the flame, and by imparting heat down the tube, the tallow is kept for a continuance in a melted state. The hot water is to be poured in before lighting the lamp. When pieces of heated metal are used, the upper part of the lamp is to be taken off to admit of their being put in the proper place. Outside of the tube for supplying air to the interior of the flame is another tube, containing the wick, having several slits formed therein, through which the liquid tallow flows to the wick. There is also another and larger slit in this outer tube, for the purpose of raising the wickholder, which is of the ordinary construction, having a projecting stud which moves up and down in the slit, and another stud which moves in a spiral round the air tube; so that when the tube is turned round, the wick or cotton rises or falls as desired. On the upper part of the tube are three projections, against which one of the arms of the frame of the glass shade comes, and when that frame is moved round, the tube will also be moved round, and thus raise or lower the wick.

The claim is to the mode of constructing lamps for burning tallow, or other fatty matters, or wax, by combining with a vessel to hold the tallow or other substance, a vessel to contain hot water or heated pieces of metal.

sends corresponding letters down to the receiving spout-the action of the levers on the columns of types being so adjusted that only one type can be detached at a time. The spout is curved downwards towards its termination for about 10 or 12 inches, and when the machine commences work, is filled with quadrats the whole length of such curve, which serve as a support for the letters to fall on, till a sufficient number of letters have accumulated to furnish an abutment for those which follow. Each type as it reaches the termination of the straight part of the spout is pressed forward by a small vibrating beater acted upon by an eccentric, which is put in motion by a small train of wheels driven by a boy (as shown in fig. 2.) From the spout the types are

passed forward along a horizontal brass rail, E, to the justifying box F, where they are placed in lines, and spaced out, or, as it is technically called, justified, by an assistant composer. This justifying-box answers in every respect to the ordinary composing-stick, and is used with equal, if not greater facility. When the proper number of lines have been justified, they are taken out and placed in a galley, in the same way exactly as a composing stick is usually emptied. With the subsequent processes of imposing, or arranging the set-up matter in chases for printing from, the present invention docs not interfere.

After types have been printed from, the present practice is for the compositor to distribute them, that is, return them to

their original repositories in the case at which he stands; but with the machine the task of distribution is performed by two boys, while two others, as before stated, are occupied in setting the types in lines with which they fill the different channels.

The number of persons required to work a machine is seven altogether; namely, one to play the keys, another to justify, a third to work the eccentric movement, two to supply the channels, and two to distribute; and it is herein at first sight that the machine suffers most in comparison with the ordinary mode of composition by a single hand. Of these seven persons, however, two are females, and five very young boys; and they can set up, after three months' practice only, 6000 types an hour, while a good compositor cannot in the ordinary way, set up on an average more than 1700. The seven female and infant hands, therefore, do the work of at least three able-bodied men, and in consequence of requiring less wages, the average cost per thousand (brevier) is only twopence, which is at least onehalf less than the most ordinary bookwork can now be done for with the help of apprentices.

But when the young women employed in playing the keys and justifying, have acquired the greater dexterity which length of practice alone can give, we make no doubt that they will be able to set a great many more than 6000 types an hour. The labour, too, of the boy employed in working the eccentric may be wholly saved; for he does nothing which might not be equally well performed by a pedal movement, acted on by the person who plays the keys, (after the manner of the old spinning-wheel,) or by connecting the eccentric movement by means of a band, to the steam engine (where one is employed to work the press, as is now so usually the case).

The maker of the machine now exhibiting in Chancery-lane, is Mr. J. G. Wilson, of Clerkenwell, and to the assistance which the patentees have derived from his skill and ingenuity, much of the perfection at which they have rerecently arrived is, we understand, owing. The cost of a machine is about 1007., in addition to which the patentees propose to charge a small sum annually for licence to use it.

Sir,The following description of a new method or process in engraving, I hope you will find a place for in the Mechanics' Magazine, as it affords great facilities, and probably may become useful to some of your readers who practise this beautiful art.

First provide a square wood or metal frame (see fig.) about 7 inches each way in dimensions; next take a quantity of fine needles, all of one size and height, and arrange them in rows parallel to each other, similar to the lines of a printed book, each succeeding line being placed in contact with the one previously set up, and alternately pushed half the diameter of a needle forward, so that they will present this appearance. which represents eight needles arranged, the first one in the top line falling midway between the other two below-that disposition being kept up all the way. When a sufficient mass of them is formed to fill the cavity of the frame A, they are placed therein, made even at their sharp ends, and then fastened by means of the screw B turned by means of a milled head. When all this is accomplished, a flat and polished plate of copper, or steel, previously covered with engraver's "ground," is laid on the pointed surface of the mass of needles, and carefully pressed thereon by means of a screw, or other power. It will be found on inspection that the ground will be cut through, and the copper exposed at every point the needles have touched, provided the process has been properly conducted. The effect is now put in by corroding the plate with a mixture of nitric acid and water, stopping out the lights, &c., with varnish in the usual manner, so as to produce the required depth of tone. A second (but indiscriminate) application of the mass of needles to the plate previous to its being etched, is also a great