272 NEW PATENTS—CORRESPONDENCE, ETC. FIRE-ENGINE. A new Fire-engine has been invented at Berne, by a mechanie named Schenk, which possesses much greater facility than any former machine of the same description. Its force is said to be so extraordinary, that the column of water which it sends out will, at the distance of 100 feet, easily break up the pavement of the street, untile the houses, and demolish their masonry up to the second floor. MACHINE FOR UPROOTING TREES. A Toronto farmer says, in a letter to an American Paper, that he had "just seen a Machine for pulling up the Stumps of Trees, invented by a Mr. Harris, an ingenious mechanic, which is extremely powerful, multiplying the force applied to it 700 or 800 times, which also can be increased or diminished as occasion may require. It is capable of pulling out the largest stumps, and can be moved from place to place by a single yoke of oxen: it is, withal, very simple, and may be worked by either men or horses. The machine will, when delivered and erected, cost about 25 dollars." TO PREVENT MISCHIEF BY ROOKS. Take a straw-rópe, such as is used in some counties for thatching, and stretch it across the field from about the middle towards the fences, supported by stakes fixed in the ground, to raise it a few feet. This is a suf ficient notice to the rooks to keep off. If fields are large, other ropes may be placed at a proper distance; for if food grows scarce, they may, after cautiously reconnoitering for some time, approach to within 200 or 300 yards of the supposed trap. quetry, and other fire-arms. Communicated to him by a certain foreigner residing abroad.--Dated April 23, 1825. Thomas Alexander Roberts, of Monford-place, Kennington-green, gentleman; for a method of preserving potaDated April 23, 1825. toes and certain other vegetables. Samuel Ryder, of No. 40, Gowerplace, Euston-square, coachmaker; for an improvement in carriages, by affixing the pole to the carriage by a newinvented apparatus.-Dated April 28, 1825. Daniel Dunn, of King's-row, Pentonville, manufacturer of essence of coffee and spices; for an improved apseparating the infusion of tea or coffee paratus for the purpose of beneficially from its grounds or dregs. - Dated April 30, 1825. James Fox, of Plymouth, rectifying distiller; for an improved safe to be used in the distillation of ardent spirits. -Dated May 14, 1825. TO CORRESPONDENTS. If J. B. C. D. has really made the discovery he speaks of, there is no doubt he may obtain both profit and honour by it. We would recommend him to apply to the Commissioners of Weights and Mea $ures. Anti-Hippopotamus would be much obliged to Mr. Thomas H. Bell, if he would inform him how to mount his Water-horse without capsizing it? Communications received from-Felix D. D. E.-Plane-J. Walker-Taper— P. Smith-Dick Forge-Samuel SmithIkey Pringle-Timothens-R. W.-D.— A. R. F.-A Reader in the Potteries-A Seaman. Advertisements for the Covers of our Monthly Parts must be sent in to our Publishers before the 20th day of each Month. NEW PATENTS. Augustin Louis Hunout, of Brewerstreet, Golden-square, gentleman; for certain improvements in artillery, mus Communications (post paid) to be addressed to the Editor, at the Publishers', KNIGHT and LACEY, 55, Paternoster-row, London, Printed by Mills, Jowett, and Mills (late Bensley, Bolt-court, Fleet-street APPARATUS FOR RAISING WATER SIR,-As your valuable Magazine appears to be open to experimentalists, as well as to practical men, I trust you will find the following communication worthy your notice. I found, by repeated experiments, that after filling a (wine) bottle with boiling water, and then turning it bottom up, the air that passed into the bottle as the water ran off, became rarefied to double its bulk or volume; for immersing the bottle neck downwards in cold water, it became half full of water in a short time. I then pursued the experiment in the manner described in the prefixed drawing, and found the result similar to that in the bottle. Description of the Drawing. AA, a tin boiler, about twelve inches deep, closed at the top, containing two or three gallons of water kept boiling by the fire in pan BB. CC, a tin pipe, one inch and a half bore, soldered into the top of AA, and passing down about seven inches into the boiling water. At the bottom of CC are several small tubes, intended to make the passing air spread through the boiling water. DD, a nine-gallon beer cask, having two strong additional heads, and the upper original head perforated with holes to let the condensing water spread like a shower bath; the whole cask made air-tight by pasting paper twice over it. E, a small funnel, with a water-tight plug on the top of DD. F, an inverted syphon, kept full of water, which covers a water-tight plug or valve. G, a pair of bellows, with a valve opening upwards; connected below is a copper pipe, one inch and a half bore, passing into the lower part of DD.— There is an air-tight cock added to this pipe at Q, and another on the pipe HH (connected with the tin boiler, AA), which passes into the upper part of DD. The copper tube, II, conveyed the raised water into DD, near the top, in order to complete the condensation; I then began by letting a little water in from the funnel, E, above, still keeping its plug under water. Then followed the Operation. The boiler, AA, being close, and having no communication with the atmosphere but through its pipe, CC, I first opened my air-tight cock, QQ, then made a few strokes with the bel lows, G. The moment hot air came out of its valve, I stopped the air-tight cocks, then let in a little water from the funnel, E, and the water rushed up instantly through the tube, II, and filled the nine-gallon cask about onehalf. To let the water off, I opened the cock in the pipe H, and it all ran off through F. I made some strokes very rapidly after the pipe, II, became full. I have given you the experiment as I made it, but it now appears to me that the bellows had better blow into CC; then both the air-tight cocks might be removed, and a much simpler mode substituted in lieu of them. I am, Sir, Your obedient servant, Z. The writer adds, in another communication to us-"I believe this experiment to be original. It succeeded beyond my most sanguine expectation, the work not being of the best kind, and my workman a carpenter's apprentice. Its simplicity is obvious for raising water, because any quantity of atmospheric air may be rarefied and condensed by keeping about ten gallons of water boiling: the steam-engine requires a boiler proportionate to the power produced." ELASTIC GUM. SIR,-Your Correspondent, "Mechanicus," seems not to be aware, that the title, "Elastic Gum," is emphatically applied to Gum Caoutchouc, or India Rubber; but as he may not know how to obtain it in a fluid state, it will, perhaps, be acceptable to state the method he must pursue. Put a small quantity of caoutchouc, sliced very small, into a three or four ounce bottle, and nearly fill the bottle with spirits of turpentine; place the whole in a large saucepan containing water; keep the water boiling, and often shake up the ingredients. When the turpentine seems to be saturated, strain the fluid SIR H. DAVY'S METHOD OF PROTECTING THE COPPER OF SHIPS. 275 through a rag into another bottle; Bradford, July 18th, 1825. FACTS PROVING THE EFFICACY OF (From the Annals of Philosophy.) gle adhesion of any kind, and, as far as could be judged from the smoothness and appearance of the copper, it had not been at all worn by any chemical corrosion. The iron, which was about an inch and half in thickness, is considered a sufficient protector for two voyages more. 2. The Elizabeth yacht, belonging to the Earl of Darnley, was protected by two pieces of malleable iron in the stern, in May last, equal to about 1-125th of the surface of the copper. After being employed in sailing during the summer, she was examined in November, when her bottom was found free from adhesions of any kind, and apparently untouched. The copper was bright, and even the nails not tarnished. In the course of the summer a few small barnacles had adhered to the rust of iron, which were easily and immediately washed off; but no weed or shell-fish had ever fixed on the copper, which appeared in the same state as when she left the dock. The following examples we owe to the kindness of Dr. Traill: The ship Huskisson, belonging to Mr. Horsfall, was lately in dock, after a voyage to and from Demerara, where she lay some weeks, in a river remarkably favourable to the adhesion of parasitical animals and weeds; yet, when I examined this vessel, her copper appeared perfectly clean, as far as it could be seen, when she was purposely set by the stern in unloading, in order to show her copper at the bows as low as possible. The Captain stated, that before coming into port, while yet in clear water, he had seen her bottom even to the keel, and it seemed to him quite clean. This ship was defended by two bars of malleable iron bolted along the sides of her keel by copper fastenings, which cover about 1-90th of the surface of 'aer copper. The Elizabeth, a vessel defended exactly in the same manner, with metals in the same proportions, had made the same voyage. Both had been newly coppered when they last left Liverpool; and the Elizabeth's 276 SIR H. DAVY'S METHOD OF PROTECTING THE COPPER OF SHIPS. copper appeared equally clean as that of the Huskisson when unloaded; but as she did not enter a graving dock, we cannot absolutely say whether she was quite clean, especially as the copper of the Dorothy (about to be mentioned) appeared equally so, until she was seen in the graving dock, when the flat part of her bottom was found to be quite covered with barnacles. The copper of the Huskisson, there is reason to believe, was perfectly clean, as was proved in the next case. The ship Dee-A very large vessel belonging to my relative, Mr. Sandbach. The ship was newly coppered about twelve months ago, and a bar of malleable iron, about 7-8ths of an inch thick, and three jinches broad, was fastened on each side of the keel by iron spikes. It covered about 1-90th of the surface of her copper. Since that period she has made two voyages to Demerara, and was, at the conclusion of the last, put into a graving dock, when her copper was found perfectly free from corrosion, and there were scarcely any substances adhering to it, except a very few minute barnacles, near the keel fore and aft. This case shows, that over defence was not the cause of the foulness of the bottom of the Tickler, for both in this vessel and in the Huskisson the proportion of iron to the copper was greater than in that ship. The iron spikes employed to fasten the iron on the keel of the Dee, were so much corroded, as to endanger the falling off of the bars; copper nails are, therefore, to be preferred. The Dorothy.-Dr. Traill states, that the following particulars of the Dorothy's outfit and return, were communicated to him by his intelligent friend Mr. Horsfall, one of the owners of the ship, in the beginning of May : far preserve the copper from corrosion, that it might be permitted to run a second voyage to India without being renewed, which can seldom be done with perfect safety. The iron extended from one end of the keel to the other, and was fastened on with copper nails with large heads. The Dorothy, thus defended, sailed again for Bombay in June, and returned to Liverpool about a month since. She was put into the graving dock yesterday (May 3), and an examination of her bottom took place as soon as the water had left her. "The copper appeared no more reduced than at the termination of the first voyage. The iron was diminished generally about three-quarters of an inch in breadth, and from one quarter to half an inch in thickAt the ends of the vessel, for about two or three feet, the iron was much more reduced than at any other part. ness. It was covered with the usual rust, not at all resembling cast iron, under similar circumstances. The flat of the ship's bottom, from end to end, and from six to eight feet in breadth, was full of fleshy barnacles (lepas anatifera) of uncommon length, and a few of the large hard shell species (balanus tintinñabulum).* Note by Dr. Traill. We remarked that the specimens of the lepas anatifera were considerably larger on the starboard than on the larboard side of the ship. On noticing this to the Captain, he informed us that the larboard had been the lee side of the vessel, almost constantly during the passage to Europe, and consequently most deeply immersed in the water a circumstance in the economy of these animals not unworthy of notice. It is evident that in all these last cases, particularly in the ship Dorothy, the proportion of iron has been too large, and the quantity of calcareous earth on the bottom of this "The Dorothy had been coppered about a year, and had made one voyage to Bombay and back to this port, when, in May, 1824, it was determined to place bars of iron, four inches broad, and one inch thick, along her keel, covering about 1-70thpart of the copper, in the expectation that the iron would at least so ship proves that the electro-negative action has been in excess. *Sulphuric acid was used to loosen and detach the shells. |