198 BELL'S MARINE CRAVATS-CAPTAIN MANBY'S FIRE-ENGINES. The driver is secure from storms; and, in consequence of his being thus protected, can drive any distance necessary for one person to drive-say fifty or more miles. BELL'S MARINE CRAVATS. SIR,-I am convinced that my namesake and former acquaintance, Mr. Thomas Hindmarsh Bell, is, like the renowned Marquess of Worcester, actuated by too honourable motives to knowingly put down other men's inventions, without nominating likewise the inventor," he will therefore not be displeased to learn that his Marine Cravat is only another name for "Scheffer's LifePreserver," the utility of which was so well exemplified by the ingenious inventor last year in the Thames, and witnessed by thousands of admiring spectators. Mr. Scheffer's contrivance does not depend on cork for its buoyancy, being composed of skins without seam, and perfectly air and water tight; it is, when wanted for use, instantly inflated by blowing into a small aperture left for that purpose, and furnished with a stopcock to prevent the egress of the air. This apparatus is of signal service to persons learning to swim, and would, if generally adopted, prevent those painful accidents so prevalent in the bathing season, particularly in the vicinity of the metropolis. It is a common practice for the young swimmer to throw himself upon the cord connecting two pieces of cork-wood; but this is a plan replete with danger, as, in case the float passes down towards the feet, that part of the body will be kept at the surface of the water, whilst the head will descend. I have known two or three valuable lives lost in this manner. I am, Sir, yours heartily, 2, Commercial-road, Whitechapel, ture of J. H. Z., requests to be informed "where the engines or vessels for the speedy extinction of fire, described in the 58th Number of the 'Mechanics' Magazine,' may be had, and the price of them; also of the condensing syringe, from an opinion they may be of infinite service;" I beg leave, in reply, to say, that the person who made them for me, and to whom I paid 201. for the set, is not now in the kingdom: but, as many improvements were found necessary while constructing them, such alterations consequently increased the expense; I therefore have no doubt but they now may be perfected much under that sum. My object in producing the Fire Curt, containing apparatus for the speedy extinction of fire, is thus stated by me to a Select Committee of the House of Commons:"To avert the dreadful calamity arising from fires in London, from a persuasion that the day will arrive, perhaps when I am no more, that a prompt method to check the progress of the flames for the preservation of life and property, will be hailed as important from motives of humanity and policy," Under in view the desire to derive benefit this conviction, and, as I never had from this or any of my productions, the public are at full liberty not only to apply them, but to make any or all for sale for their own advantage. casion to call the attention of the I must avail myself of this ocpublic to the evidence of the late Mr. Fielding, one of the Magistrates of Queen Square Police Office (a copy of which is herewith enclosed), on the subject of a firepatrol in London and in all large towns. With that most intelligent gentleman I had many conferences, and felt, with him, that a wellorganized fire-police would be of the greatest imaginable good. To adduce proofs that some more effectual protection to life and property, from fire, is required than is at present in use, I shall not deem it necessary, in confirmation of the present insufficient system, EGYPTIAN ORE. to expatiate at large on the melancholy and destructive consequences attending it; because, scarcely does a week transpire without presenting to our immediate notice some additional case of distress to excite our commiseration, and demand our best efforts to prevent the recurrence of such calamities. I cannot conclude without saying the public have a right to expect better protection from the Insurance Companies than is at present given. The expense attending the furnishing of Fire Carts for London, I should imagine would not exceed 5000l., that is for 250 sets, to be placed as described by me in the 58th Number of your work, under the superintendence of the fire-police, arranged according to Mr. Fielding's plan. 199 man be provided with his axe and his link or flambeau; then this would be such effective means of security from fire, that the public would be highly pleased with such an establishment. It would be equally beneficial to the offices themselves, for it would be a vast provision against the accidents of fire; for these men, upon the discovery of a fire, might proceed with their axes, and with their lights, into the houses where the accident occurred. Another thing I shall these two men, in their walks about the take the liberty of suggesting, is, that town, should have, under the authority of the Magistrates in the different districts, the office or power of constables." EGYPTIAN ORE. ་ SIR,-In your 91st Number, page 111, your Correspondent Quibus' wishes to know whether the metal manufactured into various articles and sold by Mr. M'Phail, under the name of Egyptian Ore, answers the description given of it by the inventor. I can assure him that it does not, as I will prove. Having heard of the excellent seals which were made of this metal, I was induced to purchase a small one for trial, for which I paid 7s., which, certainly, for five or six days, had every appearance of fine gold; at the expiration of which time it began to change colour, and finally put on the appearance of common brass. Has any plan ever suggested itself to your mind, of establishing a better system of preventive Police, than what at present exists, independent of the one which you have mentioned, namely, a Superintendent Constable in each parish? "Principally my thoughts have been turned upon the efficience of such a superintendent character forming the most beneficial preventive imaginable of crimes, at once simple and most powerful. May I take the liberty of suggesting another thing, which I communicated to Mr. Perceval very shortly before his death; I likewise did so to a Captain Manby, who has been much noticed for his mathematical exertions, desiring him to make use of the idea, or avail himself of it as his own. The suggestion was this: There are upwards of fifteen insurance offices against fires in London; I sug- you may pass your own opinion gested, that if two firemen from every one of those insurance offices were to traverse up and down the streets of the metropolis every night, they would cross one another often and often. Let every If, through the insertion of the above, I may be the means of preventing your Correspondent from being deceived, I shall be much gratified. 1 I am, Sir, yours truly, P.S.-I have enclosed the seal above alluded to, in order that upon it. [It is exactly of the description given of it by our Correspondent.-EDIT.] SIR, I herewith send you a description of a Filtering Apparatus, which I tried for rain water for several years, and founu to answer extremely well.. It has, I think, several advantages over the one described in No. 22, page 21, and is as complete, perhaps, as can be made. The name of the inventor. I do not recollect. Description. A, the vessel containing the unfiltered water. B, the filtering vessel. C, the vessel to contain the filtered water. A leaden pipe, of small bore, communicates from A to B, in the manner represented in the drawing, in which, at D, is a cock, to regulate the quantity of water passing through it in a given time. By having the handle of this cock a lever, six inches or a foot long, and the end which is farthest from the cock terminating in a point, and a scale fixed behind it, to show how far it is turned, the rate of filtration may be regulated with great exactness. STEAM VESSEL WITHOUT PADDLES, CYLINDER, PISTON, ETC. 201 E is a ball-cock fitted in the pipe, the ball of which being in C, stops the process when C is filled. F is a cock, which will draw water from this pipe. G is a false bottom, filled with holes, and fixed in B, a few inches from the bottom, immediately above the entrance of the pipe communicating with A. From the top of B, a small pipe conveys to C the filtered water. On the false bottom, G, are several strata of cleun washed gravel, the coarsest at the bottom, and the finest at the top; the whole occupying, perhaps, one-third of the space between G and the pipe at the top. On the top of the gravel is a piece of strong flannel, secured by nails to the sides of the tub, and the tub is filled to within two inches of the pipe with fine clean washed sand, or, if it be preferred, for the sake of sweetening the water, as well as clearing it, with sand and charcoal, in separate layers; taking care that the uppermost is of sand, and that another piece of flannel is placed on the surface of the charcoal, the more effectually to secure it from rising, in consequence of its lightness. B should have a loose cover, to keep out the dust, &c. I had one for C also, with an aperture for the ballcock to work. The principal advantage of this apparatus over the one before-mentioned, as described in your work, is, that by stopping the cock D, and opening F, and thereby changing the direction of the water in B, the sand and gravel are easily and effectually cleaned from the impurities they may have acquired. Another advantage is, that by the regulating cock, D, the rate of filtration cannot exceed any desired limit; whereas, by the other plan, the rate depends entirely on the quantity of filtered water drawn off for use. I am, Sir, yours, &c. J. S. M. P.S. As some of your readers may not be aware of it, I may mention, for their information, that rain water is much better preserved sweet during the summer, by being kept in an underground reservoir, than when exposed to the variations of the temperature of night and day. PLAN OF A STEAM VESSEL WITHOUT PADDLES, CYLINDER, PISTON, ETC. SIR,-This figure is intended to show the probability of Steam Vessels being propelled without paddles, and the usual cumbrous machinery of cylinder, piston, &c. by the action of the steam, almost immediately against the resistance of the water, at any convenient depth. The part below the line AAA represents the lower outside part of the vessel; above that is the inside. B shows the upper part of the boiler, with the safety valve. CC, a pipe fixed over a hole in the top of the boiler to convey the steam into an air vessel,D,which has two valves opening inwards: one, a, to admit air after each stroke; the other, b, to receive the steam. The latter is to be kept shut by a bar fixed on a spindle turning inside, having one end coming through the air vessel, with a bent handle, having a ball, E, sufficiently heavy to keep the valve, b, shut, at any pressure the steam is to work at, yet so adjusted to that pressure, that a man may constantly open 202 STEAM VESSEL WITHOUT PADDLES, CYLINDER, PISTON, ETC. and shut it, in order to work the vessel. At the bottom of the air vessel, D, are two pipes, passing through the sides of the vessel above water-level, one on each side, as at F; to these are joined the conducting pipes, G; through these pipes is conveyed the impulse of the steam into a trunk on each side, and as near as may be to the keel of the vessel; the mouths of these trunks may be of any form, and should make an angle of about 450 with the keel. A valve opens inwards at the highest end of the trunk, to let the water pass after each stroke; there is a valve also to keep the water below it,, in order to gain all the resistance at once. The dotted lines show a piece of wood brought to an acute angle, to prevent the trunks checking the motion of the vessel.. Operation. When the steam is produced in the boiler, B, by lifting the weighted ball, E, the steam will rush into the air vessel, D, and drive the air out of it (being heavier than steam) down through the pipe, G, into the trunks, one on each side the keel; there it will be resisted by the pressure of the water outside the trunks, and that resistance will be thrown against the valve, I, and thus propel the vessel. The continual opening and shutting the valve, b, in the air vessel, D, will cause a continual reaction of the water, which will open the valve, a, in D, and let in fresh air at cach stroke, 'while the waste steam will escape through this valve, a. If there were no air vessel, D, the steam would probably be too soon condensed, by coming in contact with the water in the trunks, otherwise this were the better mode; and then a swingplate, opening outwards at the mouth of the trunks, would close after each stroke, and a considerable suction would be felt at the valve, I, which would draw the vessel forward almost as much as the impulse of the steam would force her at each stroke, because then the air vessel being away, and the only valve, b, working in the steam pipe, the condensation of the steam in the trunks at each stroke would produce a vacuum in the steam pipe, which would be felt immediately by the valve, I, opening, and the vessel being drawn towards the front water in the same ratio as that water is drawn towards the trunks caused by the vacuum. There might be two trunks on each side the vessel, acting alternately. The trunks may be made of strong oak; and suppose each of them to be three feet high by two feet and a half, and six feet below water-level on an average, I take the gross pressure at about 3 lbs. to each square inch of the mouth of the trunks. Then, 3 feet, or 36 inches x 30 inches 1080 inches x 3 lbs. =3240lbs. |