through the riband and the round wire, he will find them conducted with equal facility; of course, as Mr. Hill is so well versed in electricity I need not point out methods of proving the amount of conduction through each wire. I have the honour, &c., MARTYN ROBERTS. FIRE-BASKETS. Sir, The present fire-baskets are adverse to perfect combustion, to good draught, to steadiness, to warmth, and to facility of mending the fire. A fire-basket should be of thinnish cast iron (thinnish for lightness, but not in too great a degree, for fear of unsteadiness); the backing, and the sides, should have holes in them, like the inner back of most register grates, but much more numerous and smaller, (this ensures perfect combustion); the bottom to be grated in like manner and of the same thickness, (for steadiness,) as ordinary grates, and the front to have very slender bars like the present fire-baskets. The dimensions to be as follows: height 6 inches; width in front, 8 inches; at back, 5 inches; and the internal depth from front to back 44 inches. Some of your readers may perhaps manufacture such for the present season. A CONSTANT Reader. THE GREAT BRITAIN STEAMER. Sir,-Your publication has given an able description of the "Great Britain" steamship, which has materially assisted to excite great interest in the public mind; and imagining your pages are still open to any observations, whether in approval of the merit (if any) of the management pursued, or in denunciation of the indiscreet expenditure of the company's resources, I beg leave to request a place for a few remarks on these points. I am one of the unfortunate shareholders, and am now become so sick of the continued demands, and want of money, that I feel almost reckless of the consequences. In August last, we were told that the cost of the new ship would not exceed 76,1167.; but at the meeting held at Bristol, on Friday last, just three short months after, we are told that the estimated cost is not to exceed 100,000. Surely, this is arithmetical progression with a vengeance, being at the rate of nearly 96,0007. per annum. I respectfully and most feelingly put it to my brother shareholders, whether it is not better, instead of reducing the weekly wages, from 3671. to 3001. as proposed, to increase them, and get the thing done, if possible, before another three months pass over our heads, or we may be told that the estimated cost will then not exceed 123,8847. A suggestion was made that the services of Mr. Guppy, who officiates as engineer, should be dispensed with, and thereby save 5007. a year; but I say no! If we are to finish the ship, let us procure the additional assistance of a real, practical, industrious engineer, in whose ability we may place confidence for the short time we are to remain a company, and that the 3007. or 4007. paid weekly be properly spent, and that the system of making, altering, and re-making, which has been so long practised to our cost, and of advantage to none but our salaried servants, be put an end to. I wish not to be understood as hinting at any incapacity in Mr. Guppy as engineer, seeing that the title and diploma may be had even easier than by setting one's legs under the office table of a C. E. in chief, for a couple of years. If 20,000l. is to be borrowed, let it be done at once; let the 17,000l. calls be enforced, the ship finished and sold, if possible; wind up the concern, and dismiss the living, as well as dead incumbrances. Judging from past experience, I dread to anticipate, that the more we spend the more we shall be required to supply. An attempt was made to comfort us by the prospect of realizing 27811. by the sale of timber and stores, but what the stores are, does not appear. Presuming it to be secondhand timber, sold at a good price, it would require, I am informed, about 55,620 cube feet, equal in bulk to fully one quarter of the bulk of the vessel. One cannot but think that the people of Bristol, with the exception of two, are perfectly innocent of sleeping with one eye open;" to me it appears that they keep both shut. I am, Sir, A LUCKLESS SHAREHOLDER. Bath, November 15, 1842. DOMESTIC PUMP. Sir,-Some time ago, on perusing your useful and instructive Magazine, I noticed with pleasure an account of a small pumping-engine to be fixed on board steamers, in order to relieve the poor stokers from their arduous duties in pumping up the boilers when the engines that work the vessel are not in motion. I beg now to call your attention to a new mode of raising water, invented by a Mr. Egeldine, for an equally laudable purpose, namely, the ease and com fort of the domestic servant. This talented gentleman has lately erected one of the machines at Mr. Harmer's seat, Ingress Park, Greenhithe, which is now in daily use, and the performances, I should say, are perfectly satisfactory, though the inventor still thinks he can improve it considerably. One of the servants, when I was there, was procuring more water with it than I ever saw raised with a pump in the same space of time, and certainly with not a quarter the labour of a common pump handle. Much praise is due to the inventor, for the simplicity of its construction, and also for the taste he has displayed in its appearance, which is both light and elegant. It is to be hoped, that as soon as he has secured his patent, he will make this valuable invention known to the public, who cannot fail shortly to adopt these machines generally, more especially as the cost is very trifling. Knowing how willing you are to make known any new invention, I hope you will favour me with a corner for this notice at your earliest convenience. Yours, &c. &c., A CONSTANT Reader. WORKING FIRE-ENGINES. Sir,-In the present volume of the Mechanics' Magazine, page 364, your intelligent correspondent, Mr. Baddeley says, "In working fire-engines, under certain circumstances, a very striking and somewhat inconvenient illustration is afforded of the vis inertia of fluids. This happens when the hose is led to the top of a high building, or has by other means a great altitude given to it. So long as the engine is worked, and the ascending column of water kept in motion, the jet is delivered from the branch pipe in the usual way; but, should the engine be stopped for a few minutes, to shift the hose, &c., the pressure of the quiescent column of water cannot be overcome. beginning again to work the engine, the delivery valves become set in an open position; the engine handles fly freely up and down, as the water passes from one barrel to the other, which is the only effect that can be produced. The vis inertia of the high column of water contained in the elevated hose cannot be thus overcome, but must be got rid of in another way." On Now, Sir, I do not see what the vis inertia of fluids has to do with the effect your correspondent complains of; for, in my humble opinion, it arises from quite a different cause; and I should think there is scarcely a practical fireman but is aware of it, and has a remedy at hand. The cause generally originates from the more or less unsound state of the cock, feed or suction pipe, particularly when more than one length is on, which admits a portion of air through the seams, joints, &c., yet not sufficient to prevent the engine fetching, or charging itself at first. The consequence is, that on any stoppage of the engine for a short time, to shift the hose, &c,, the air so admitted into the feed-pipe displaces the water therein, and on the order "Go on," the air must first be extracted and allowed to escape through the main valves, before the barrels will be charged with water, and work. But the main valves are firmly closed by the superior weight of the column of water, instead of being set in an open position, as Mr. Baddeley says; and, by the motion of the piston up and down, a portion of the air in the feed pipe gets into the barrels, and is there alternately expanded and condensed, without any discharge of water from the branch pipe; the spring or force of the air so condensed not being sufficient to open the main valves and escape. To remedy the evil complained of, without any addition to the engine, all that is necessary is, previously to discharging the water on the fire, to pump some water into the cistern of the engine, (which I have frequently done,) say till it is half full, and when the engine becomes affected by the vis inertia of the fluid, to turn the handle of the cock a few seconds to feed from the cistern, when the barrels will become charged with water. Immediately turn the handle back, and the engine will work from the feed pipe as usual. I have tried this several times, and always succeeded. If the feed pipes, cocks, &c., always continued sound, or when working from the cistern, the engine would always work after any stoppage, whether fitted with angular valves or others. Trusting to your kindness for an early insertion of this in your valuable Magazine, I am, Sir, your obedient servant, AN OLD SUBSCRIBER. Maidstone, Nov. 10, 1842. OPTICAL DELUSION IN RAIN DROPS. Sir,-While under a shower of rain, 1 have stooped my head to allow the rain to run from my hat, and thus looking down perpendicularly on the drops as they fell, they appeared to be as black as ink; so much so, that at first I thought they were discoloured from the black 'dye of the hat. The same rain drops, looked at horizontally, while yet hanging to the leaf of the hat, sparkled like diamonds. J. N. MR. READMAN'S BAROMETER. Sir,-Having read the communication of Mr. Coathupe, in your Journal for October 22, relative to my improvements in barometers, in which he lays claim to priority of invention, on the ground of a letter which he addressed to the editor of the Meteorological Journal, in February last, I beg leave to inform that gentleman, that, in addition to your testimony, Mr. Editor, in my favour, I am able to bring forward evidence to prove that my invention had been matured by me full half-a-year before the publication of his letter. From the concluding paragraph of Mr. C.'s communication, the reader would be apt to infer that the inventions of that gentleman and myself were identical, whereas the principle of suspending or placing the cistern of the barometer on a spring or balance is the only point in which they do agree; the purposes to which that principle is applied being totally different. The use to which I have applied this principle, and which constitutes the chief value of my invention, consists in the substitution of the weight of the mercury in the cistern, instead of the length of the barometric column, as the index of the atmospheric pressure, by which means several defects in the barometer are obviated. Now, the sole use to which Mr. Coathupe, in his letter, proposes to apply the same principle consists in the selfadjustment of the surface of the mercury in the cistern to the zero point of the scale. The identity of the two inventions, therefore, the reader will perceive, extends no farther than to the principle on which they are founded. ABSTRACTS OF SPECIFICATIONS OF ENGLISH PATENTS RECENTLY ENROLLED. JAMES CLEMENTS, OF LIVERPOOL, for certain improvements in composition for ornamenting glass and picture frames, and articles for interior and other decorations; also, for the manufacture of toys and other carriages. Patent dated, March 4, 1842. The pulp of potatoes, boiled, roasted, or steamed, is to be mixed with some suitable binding material, as fine saw-dust, ground brick, &c., and this, it is said, will form a composition, which may be cast in moulds of any ornamental form desired. EDWARD SLAUGHTER, OF BRISTOL, ENGINEER, for improvements in the construction of iron wheels for railway, and other fancy articles. March 4, 1842. The spokes and tire are to be of malleable iron, and dovetailed the one into the other; after which, the nave is to be cast on the ends of the spokes. The patentee also gives his spokes a peculiarly curved form; but to this he makes no claim. THOMAS HEDLEY, OF NEWCASTLE-ONTYNE, GENTLEMAN, AND CUTHBERT RODHAM, OF GATESHEAD, MILLWRIGHT, for an apparatus for purifying the smoke, gases, and nauseous vapours, arising from certain fires, stoves, and furnaces. March 7, 1842. A revival of the plan, patented (we rather think, more than once,) many years ago. The smoke or vapours are caused to traverse two shafts, one ascending and the other descending, from the top of the latter of which a shower of water is constantly falling, which washes the smoke or vapours free from all impurities. The only difference between this and the former plan is, that six flues are employed instead of two; that is to say, three ascending flues, and three descending, or shower flues. HENRY BARRON RODWAY, OF BIRMINGHAM, WINE MERCHANT, for improvements in the manufacture of horse-shoes. March 7, 1842. 44 Every person must have noticed that, in a horse-shoe, as commonly made, there is a small groove towards the outer edge, to receive the heads of the nails, by which the shoe is secured to the foot of the horse; and, if he has a nice eye for proportions, he may also be able to call to mind that this groove is commonly about a quarter of an inch wide-never so much as three-eighths. On these rather minute premises there is here built an astonishingly sweeping patent.. Nobody," quoth Mr. Rodway, "has made horse-shoes with a groove exceeding three-eighths of an inch. I will, therefore, (happy thought!) monopolize to myself that width, and all beyond it." His actual words, in the specification before us-duly signed, sealed, and enrolled-are these: "I do not claim the making of horse-shoes with grooves, generally, but only such grooves as are at least three-eighths of an inch wide.” Make them of ths, or ndths, or 4ths of an inch, or of any size, however small, less than ths of an inch, and you are safe; but only make them of the patent ths width, or one hair's-breadth beyond it, and you shall have a costly, perhaps ruinous law-suit for your pains. By such patents as this, the encouragement given by the law of the country to new inventions is not used for its legitimate purposes, but most grossly abused. CHARLES WILLIAM.FIRCHILD, OF WESLEY PARK, WORCESTERSHIRE, Farmer, for an improved propelling apparatus for marine and other purposes. March 14, 1842. A pair of steam-engines are to be employed, as usual in steam-vessels, but the cylinders are to be fixed horizontally in the stern of the vessel, and the piston-rods are to pass through the cylinder both at top and bottom. The inner ends of the pistons are to be connected with a. crank-shaft, and the outer ends with a secondary pair of pistons, of a square form, which are to work in two hollow square chambers open to the water behind. The notion (evidently a very foolish one) of the patentee is, that the alternate action of his circular pistons on his square pistons, and of his square pistons against the columns of water admitted from behind, will propel a vessel forward much more effectually than paddles, screws, or any thing else, we presume, yet invented for the pur pose. M. S. BEACH, OF NORFOLK-STREET, LONDON, PRINTER, for improvements in machinery used for printing with type, and in the construction of type for printing. March 23, 1842. The general object of these improvements is, to extend what may be called the cylindrical system more generally to the art of letter-press printing than has yet been done. With this view, the patentee proposes that the types, instead of being set up, as at present, in flat composing-sticks, should be set up in sticks of a circular, or partly circular form, and the types themselves be tapered to suit that form; that, besides using rollers for feeding the paper and inking the types, as in the present machine printing, the types also should be adjusted on rollers; and, finally, that the paper, instead of being supplied, as it now is, in separate sheets, should be supplied in continuous lengths, of as many yards as a shaft will conveniently carry, and cut off, at any distances required, by knives suitably placed and acted upon for the purpose. Subordinate to these principal improvements there is an apparatus for damping and pressing the paper; and also a new sort of hand-press, for taking proofs. The specification of the patentee is illustrated by no less than thirty-two drawings; and it needs them, for, taken by itself, ti is very confused, (what printers would call of the pie order,) and any thing but intelligible. Of Mr. Beach's improvements themselves it is impossible to speak in terms of too high praise; they are all of them exceedingly ingenious, all more or less feasible, and some, (the supply of the paper, for example, in continuous lengths,) of obvious and unquestionable utility. JULIUS SEYBEL, OF GOLDEN-Square, MANUFACTURING CHEMIST, for improvements in the manufacture of sulphate of soda and chlorine. March 31, 1842. These improvements consist, first, in manufacturing the sulphate of soda by adding to 20 cwt. of common salt, contained in a close leaden vessel, 30 cwt. of sulphuric acid, “of 171," and heating the said vessel, externally, to from 300° to 330° Fahr.; and, secondly, in manufacturing chlorine, by employing "the vapours of muriatic acid to act on manganese immersed in water, such vapour being conducted below, and permitted to escape upward, through the water and manganese." JOSEPH CLISOLD DANIELL, OF TIVERTON MILLS, for improvements in making and preparing food for cattle. March 31, 1842. Birch brooms, or furze fences, are to be made good food for cattle, by grinding them to a fine powder, and mixing them with some corn and a good deal of chaff. Straw and hay is also to be made as fresh and succulent as new-mown grass or clover, by throwing a bundle of the former and two bundles of the latter into a close vat or tank, and steaming them together for twenty-four hours. Mr. Daniell is a great dealer in agricul tural nostrums. RAOUL ARMAND JOSEPH JEAN COMTE DE LA CHARITE, RICHARD TAPPIN CLARIDGE, OF WEYMOUTH-STREET, GENTLEMAN, AND ROBERT HODGSON, OF SALISBURY-STREET, Strand, GENTLEMAN, for improvements in preparing surfaces of fabrics to be used in covering roofs, floors, and other surfaces. April 26, 1842. These improvements consist in coating canvas with a composition called by the patentees, "Oropholithe." It consists of the following ingredients, well mixed together: Linseed-oil, 8 parts; Litharge, or white-lead, 4 parts; If If a light-coloured oropholithe be required, then unboiled linseed-oil must be used. a particularly tenacious cement be not required, or if of a darker cast, boiled linseedoil is used. Any colour can be given to the oropholithe, by using colouring matter of the required shade. The whiting and sand must be quite dry, and passed through a fine sieve previous to mixing. The thickness of the composition depends on the service for which it is required. If for places not exposed to wet, the composi tion is only laid on one side of the fabric, to the extent of th of an inch; if for places exposed to the wet, it is then laid on both sides. The claim is to the composition for covering roofs, floors, and other surfaces, consisting of the materials before mentioned, in the proportions specified. JOSEPH WARREN, OF HEYBRIDGE, for certain improvements in ploughs. May 9, 1842. The present improvements are six in number. The first consists in regulating the depth to which the share of the plough is inserted in the ground by means of a wedge (acted on by a screw) which is passed under the ploughshare from behind, and in proportion as it raises it at the back, depresses it in front; also in regulating the height and elevation of the beam, to suit the general line of draught by a peculiar combination of shifting bolts and screws. The second improvement is a modification of the second branch of the first. The third consists in a mode of raising at pleasure, the frame of the plough at the back part so as to depress the ploughshare in front. An upright rod connects the sole at the after part with the top and bottom parts of the frame, which rod is screwed at that part where it passes through the bottom part of the frame, so that by turning it round (by a spanner, or any other convenient means,) the back part of the frame is detached from and raised above the sole, and the ploughshare in front is proportionally depressed. The fourth improvement consists in giving the ploughshare, when intended to be used in the tilling of stony land, a more elongated and pointed form than usual. The fifth improvement consists in a double breasted plough, of which the chief peculiarity is, that the mould boards are so curved that they present an outline continually receding or diverging outwards from the base to the upper extremity. The sixth and last improvement consists in a wheel plough for making drains, which seems likely to answer the purpose well, but the construction of which, could not be made clear to the reader without the aid of the explanatory drawings. WILLIAM RICHARD, THE ELDER, OF BARLEY-MILLs, Leeds, ManUFACTURER, for an improved method of preventing and consuming smoke, and economizing fuel in steam-engines. July 7, 1842. A pneumatic apparatus, precisely similar in principle and action to the well-known (station) gasometer, is here applied to the purpose of supplying atmospheric air to a furnace. Every time the door of the furnace is opened to throw on fresh coals, it acts on certain levers which simultaneously open the passage to a number of air-holes, formed at the back of the bridge, (à la Williams,) and set the gasometer-like apparatus or bellows to work; and this air-feeding apparatus is provided with certain other ap pliances, by means of which (after the furnace-door is closed) it is gradually brought to a state of equilibrium or rest, and the airpassages to the furnace closed. RECENT AMERICAN PATENTS. [Selected and abridged from the Franklin Journal for September, 1842.] Jo IMPROVEMENT IN FIRE-ENGINES. seph B. Babcock.-The cylinders and pistons, or plungers, are placed horizontally, and these cylinders, with the part of the apparatus to which they are attached, are secured down to the bottom of the eistern. The pistons, or plungers are hollow, and are proIvided with valves for the admission of the water into the cylinders; they are attached to the ends of a square frame, inside, the side pieces of which are provided with racks, into which the teeth of two segment cog wheels work, said segments being attached to the brake. IMPROVEMENT IN BEE-HIVES. John M. Weeks. What is claimed as constituting this invention, and not previously known in bee-hives, is a mode of regulating the ventilation of the hive by means of tubes lined with wire gauze, and having apertures to which adjustable caps, perforated with similar apertures, are adapted. Also, combining a central box, and one or more collateral boxes, containing smaller hives, with a mode of ascertaining and regulating the temperature of the hives, by means of a thermometrical and ventilating apparatus. CANAL LOCK. Robert English.-The patentee calls this "the air and water-acting sympathetic canal lock-gate." At the upper end of the lock, which is the subject of this patent, there is to be an airtight chamber, provided with what the patentee calls "sympathetic gates," which are hinged to the lock in such a manner as to shut one upon the other, the lowermost being provided with an air-tight float. Below these two gates there are two valves, one of which communicates with the water in the upper chamber of the lock, and the other with a culvert leading to a lower level. When the first-named valve is opened, the chamber below the gates is filled with water, which acting on the float, forces up the gates, and thus closes the lock; and when this valve is closed, and that leading to the calvert opened, the water running out of the chamber to a lower level, leaves a partial vaccuum below the gates, which are consequently forced down by the pressure of the atmosphere, aided by their own gravity; a communication is thus opened between the upper and lower levels. Where the water discharges from the upper to the lower level, |