SUGGESTION FOR THE IMPROVEMENT OF MR. PILBROW's ENGINE. 251 Neither are sham Provisional Committees and sham Boards of Directors such novelties in the annals of public delusion, as to make it at all unlikely that something of the sort may be in course of perpetration here. We do but our duty, at all events, in making public what we know of the case; since every share of patronage extended to bubble schemes is not only, so much diverted from the encouragement of legitimate ingenuity and enterprise, but has a tendency to produce an indiscriminate prejudice against all new inventions, to the grievous injury of many of solid worth and unquestionable public utility. CEMENT FOR SILK- HYDROSTATIC PRES SURE ON THE VELOCIPEDE. Sir,-In reply to the question of your correspondent relative to a cement for silk, allow me to give you the result of a successful experiment I have recently made. Having an old silk umbrella much rent and worn, and for which there absolutely seemed no sufficient cure but that of a new cover, I caused a number of odd pieces of silk to be cut into ornamental shapes for covering the various rents, and having procured a small quantity of caoutchouc, in the liquid state, as sold by retail, (I got it at a shop near the S. E. corner of Leicester-square,) I spread with the finger upon each piece a thin layer of the cement, as well as upon the corresponding pieces, at the inside of the open umbrella; when dry I added a second and a third coating, after which the patches were applied to their respective places, and found to adhere very firmly. I have had the umbrella in use for some months, and find it absolutely impervious to rain-in fact better than when purchased new; and from the plan adopted in systematically shaping the patches, the effect is rather favourable than otherwise. I avail myself of this opportunity to suggest to your correspondent of Feb. 26, that if at the end of the lever of his velocipede he could contrive to inclose one or more columns of water, so as to bring to bear the principle of hydrostatic pressure, I think he might prodigiously assist his power of locomotion. The astonishing effect of this principle may be estimated from the Bramah press; and although, as a general rule, what is gained in power is said to be lost in time, it appears to me that the objection may be obviated. I remain, Sir, &c., CASES IN SCREW POWER. 1. Suppose two screws made of metal of the same quality, and passing through nuts of the same thickness, but the threads differing in inclination, and consequently thinner in one than in the other, be opposed in their passage through the nuts by an equal amount of resistance is the thread of one more likely to break than that of the other? If so, why? since, both being half thread and half space between, there will be the same quantity of metal to bear the resisting force. 2. If a screw with a considerable space between the coils of its thread, produce a certain pressure, with a certain force applied to turn it, will a greater pressure be produced with the same force, if one thread or more having the same inclination as the first thread, be inserted between its coils? WILLIAM SPURRELL. Carmarthen, Feb. 19. 1842. WHICH OF THE COMMON WOODS ARE Sir,-If any of your correspondents can inform me which of the common woods, in boards, stand best without shrinking, swelling, or warping, in an atmosphere sometimes dry, sometimes replete with moisture, and at a temperature varying from 100° to 150° Fahr., I shall be greatly obliged by the communication. I do not apologise for this request, conceiving it to be one of general interest to mechanics. If the answer should be found among the deals or pines, it will be necessary to state the kind. Would kyanising, or any other process, be of advantage? I am, Sir, Your humble servant, SUGGESTION FOR THE IMPROVEMENT OF Sir,-Permit me to offer the following suggestion with regard to Mr. Pilbrow's engine it is, that a pipe should be added to connect the upper and lower eduction ways, so that supposing the steam-piston to have completed its down-stroke, the steam may be allowed to flow into the top of the condenser, without giving injection, until the pistons are about half-stroke, when the top valve being closed, the remainder of the steam may be made to pass through the pipe into the lower part of the condenser, and condensed immediately. By these means there would be, for half the stroke, a vacuum in the top of the steam-cylinder, and during the whole stroke, in the bottom of the condensing cylinder, and a certain amount of pressure in the top of the condensing cylinder. Of course the valves would be reversed at the opposite part of the stroke. It is unnecessary to enter into the arrangement of the valves required by this plan, the least complex being generally the best. I am, Sir, Your obedient servant, THROTTLE-valve. make the circumstance known, through your valuable Periodical, to those interested in railway affairs; and if any of your readers should think proper to communicate with me upon the subject, I shall be happy to afford them every information. I remain, Sir, your obedient servant, OLIVER MOORE. Sneuton, near Nottingham. P. S. I have also an entirely new and superior plan of a terminus buffer. MECHANICAL CHIMNEY SWEEPING. Sir, I regret to say indisposition has prevented me from answering Mr. Baddeley's communication in your Journal of the 26th ult., under the head of "Mechanical Chimney Sweeping." As I had no object, beyond that prompted by humanity, in bringing my plan for Mechanical Chimney Sweeping before the public, and as I have stated a sufficiency on the subject, and having no particular argument of Mr. Baddeley's to refute, I shall beg permission to leave the discussion at this point, feeling assured, that to occupy your valuable columns further therewith, would neither be interesting nor instructive to your readers. I am, Sir, respectfully yours, JAMES A. EMSLIE. Newcastle-upon-Tyne, March 18, 1842. PREVENTION OF RAILWAY ACCIDENTS. Sir,-In your valuable Miscellany, Part 228, is an article under the title of the "Modern Mechanical Moloch," in which you dilate in strong and deserved terms upon the carelessness and supineness of railway companies respecting the safety of the lives of passengers, and the evident want of means to remedy this dreadful evil. From perusing the above, and from other causes, I have thought much upon the subject, especially as relates to the frightful consequences of concussions, and I feel convinced, that by a proper application of mechanical power these evils may be removed. I have devised a plan for this purpose, and constructed a working model which answers my most sanguine expectations; the principles of which are an improved buffer apparatus, by which a motion of two yards may be obtained; and in connexion therewith a selfacting break, on a very simple principle, both of which can be applied at a very trifling cost. Not being in a position to give to the world the fruits of my labour by a further elucidation of my plan, my object in now addressing you is, with your permission, to NEWEST CLYDE STEAMERS. Sir, I observe in your last Number 971, page 240, a paragraph beginning thus: What do the champions of Thames supremacy in steam-boat building say now to Clyde-fitted steamers?" and a statement follows in reference to "the theoretical curve" which I (and I venture to say many other of your readers) do not understand. However, I must beg to be allowed to ask, What do the champions of Clyde-fitted steamers say to the fact, that the engines of these fine formed wave line vessels which glide so freely through the water, are consuming from 12 to 14 tons of coal every twenty-four hours more than the Thames-fitted steamers ? It has been found that the consumption of the Thames during her run out and home, has averaged 26 tons per day of 24 hours, while the Clyde and "Solway" are not burning less than 40 tons in the same time. will the advocates of Scotch engines say to this? Here we have engines of the same nominal power employed to propel vessels of the same tonnage, yet one pair costs 141. per day more for coals than the other! What I would again strongly advise the Directors of the Royal Mail Steam Packet Company, to adopt the plan of a log-book, suggested by me in your 958th Number. Those interested in steam-navigation could then judge for themselves, and I am quite sure the London engineers would not object to the result being published. In reference to your observations on the combined cylinder engine erected by Messrs. Rennie, at Mr. Thomas Cubitt's, Thames Bank, I learn that some extensive experiments are being made with this engine, in order to determine the quantity of water passing through it as steam, together with the consumption of fuel and work performed, the results of which I think I shall be able to lay before your readers. I am, March 23, 1842. Sir, Your obedient servant, L. P. SPECIFICATIONS OF RECENT ENGLISH PATENTS. 253 "THE ANTI-JOHN-SCOTT-RUSSELL," CHAL LENGE TO THE WORLD. Sir,-In your Number of the 19th instant, under the head of Notes and Notices, there is an article upon the "Anti-John-Scott-Russell" steam-boat, which is propelled by a rotary engine, the property of the inventor, Mr. J. T. Beale, which article, I must confess, has surprised me more than any other I ever read in your valuable work. I have the honour of being acquainted with Mr. Beale, and have travelled in his boat on very many occasions. And, as I have had considerable experience in steam-engines generally, I feel that I am better qualified to judge of the properties and power of the engine in that boat, than the writer of the article in question. Sir, I have so much confidence in its performance, that I hereby offer to the anonymous writer of the paragraph, to run the Anti-John-Scott-Russell (having obtained a promise of the use of her for the occasion) from Greenwich to Richmond, and back, against any steam-boat in the world for 201. And, as I do consider the match, if made, would not be for the sake of the money on either side, I propose that the amount be given by the winner, for the benefit of the Dreadnought Seaman's Hospital. If, however, the writer of the article alluded to, should not feel sufficient confidence in the non-performance of Mr. Beale's engine to accept this challenge, I shall construe his silence into a retractation of his statement. As I consider your publication to be intended for the benefit and protection of mechanical science, and not its injury, I trust you will give the above a place in your next Number. By so doing, you will confer a favour upon Your very obedient servant, 28, Jewry-street, Aldgate, ABSTRACTS OF SPECIFICATIONS OF ENGLISH PATENTS RECENTLY ENROLLED. RICHARD WHITAKER, OF CAMBRIDGE, MACHINIST, for improvements in cutting the edges of books, and paper for other purposes; and in impressing ornaments, letters, and figures on the binding of books, and on other surfaces. Enrolment Office, March 4, 1842. The first improvement refers to the cuttingpress. Instead of the sliding cheek being urged forward by two screws, as is usual, there is an endless screw lying horizontally opposite the middle of the cheek, which takes into two horizontal toothed wheels ; these wheels take into two toothed racks, proceeding one from either end of the traversing cheek. On turning the handle, therefore, the cheek traverses backward or forward, according to the direction in which it is turned, being held tight when screwed up by a pall and ratchet. Instead of the common groove on the left-hand cheek, a dove-tailed groove is employed. The books or paper intended to be cut are placed upon a platform or table beneath the press, which is raised or lowered by means of a pinion acting in two racks, very similar to the arrangement submitted to the Society of Arts, in 1832, by Mr. Penny, and described at length in our 22nd volume. The plough adapted to this cutting-press has a brass or other metal sole, with a dovetailed projection which exactly corresponds with the dove-tailed groove before noticed, as applied to the cheek of the cutting-press. A diagonal stay is also introduced, to counteract the springing of the knife. For lettering and ornamenting the backs of books, the following apparatus is employed. The letters, ornaments, &c., employed are those invented by Mr. Baddeley, which are set up like type, within a chase of a new construction, at the back of which there is a box for receiving a heater. The book being placed upon the platform or table, and the press screwed up tight, the chase containing the desired impress is attached to a long lever terminating in a handle; the short arm of the lever is attached to an upright bar, from the lower end of which a cord passes down under a pulley, and thence up to a larger pulley or wheel having several rims or speeds. A large weight, (56 lbs.,) is suspended by a cord from one of these rims, its distance from the centre being regulated by the pressure required. On bringing down the lever, and pressing the ornament, &c., on to the arched back of the book, the shorter end of the lever rises, pulling round the wheel; the weight being thereby raised, reacts with great force upon the lever. In order to insure a level and properly curved surface to receive the impression, the back of the book is rolled, either before or after lining, with a concave metal roller under pressure. The claim is, 1. To the mode of compressing books or paper to be impressed or cut by means of the pressers worked by racks and cog-wheels driven by a screw. 2. To the mode of raising the platform for supporting books or paper, by means of two toothed wheels and toothed bars. 3. To the application of a dove-tailed slide and diagonal stay to the blade of a plough. 4. To the manner of working a chase, or ornamenting impressing surface, by means of the lever and apparatus connected therewith. 5. To the mode of constructing a chase or frame for holding type or ornamenting surfaces for impressing books and other surfaces, whereby such surfaces are securely held in such chases. 6. To the mode of combining a chase containing impressing surfaces, with a heater-box. 7. To the mode of preparing the backs of books, in order to insure uniformity of impressing the backs. WILLIAM CROSSKILL, OF BEVERLEY, IRON-FOUNDER AND ENGINEER, for improvements in machinery for rolling and crushing land; and in machinery to be used in the culture of land. Enrolment Office, March 8, 1842. The machine for the first-named purpose consists of a strong framing fitted with a pair of shafts for drawing by horses. Upon an axis within the framing are mounted, so as to turn freely and independently of each other, a series of rolling surfaces, the outer circumference of which is indented, so as to form angular teeth around it. Other teeth are fitted with their points in the hollows of the angular indents, at right angles to the rolling surface; these latter teeth are not placed in the line of the radius of the rolling surface, but inclined to it, so that they enter the ground more perpendicularly, and thereby have an increased tendency to penetrate and break up heavy lands, clods of earth, &c. Each rolling surface being free to turn upon the common axis, independently of the others, will, it is said, be found much more useful and effective than those heretofore made. When the machine is to travel on roads, &c., two large running wheels are put on the ends of the working axis, and removed when the operation of the machine is to commence. The machine to be used in the culture of grass land consists of a strong framing mounted on four running wheels, the front pair having a locking motion; the object of this machine is to cause narrow cuts or trenches to be formed, at short intervals, through the turf down into the soil, and to deposit seeds and manure in such cuts or trenches. An axis or shaft lies across the front of the machine, and carries two arms, which, by connecting links, move bars that slide in grooves at the ends; these bars are affixed to a series of blades or cutters, (six in number,) by passing through an opening formed in the upper part of each cutter. These cutters pass down through slots or openings in a horizontal plate; by this ar rangement, whenever the cutters become clogged, (which they are very likely to do,) the man attending the machine lifts the cutters through the plate, which instantly clears them from the accumulated soil or turf. In order to lift the cutters, and also to regulate the depth to which they shall work into the ground, there are two side levers attached to the axis or shaft, having sliding weights, in order to regulate the pressure used to force the cutters through the turf. Other levers connected to the foregoing pass over them to the hinder part of the machine, where they terminate in handles within reach of the attendant. An ordinary drill is placed upon the machine, and motion communicated to it from the driving wheels by toothed gearing, in the usual manner. The claim is, 1. To the mode of applying the teeth of the rolling surfaces for rolling and crushing land; also, the placing rolling surfaces having teeth on the outer circumference, in such manner as to turn independently of each other. 2. To the mode of arranging a series of cutters in a suitable carriage, for producing narrow trenches or cuts through the turf of grass land, whereby such cutters can be lifted and cleared from time to time, and combining therewith suitable drills for sowing seed and manure in such cuts or trenches, as above described. THEOPHILE ANTOINE WILHELME, Count DE HOMPESCH, RURICH CASTLE, AIXLA-CHAPELLE, for improvements in obtaining oils and other products from bituminous matters, and in purifying and rectifying oils so obtained. Enrolment Office, March 1, 1842. The matters to which this invention refers are schiste, or clay slate, and asphalte. The invention consists of an improved process whereby a greater quantity of oil is produced, the quality improved, and the smell removed, or greatly modified; it further consists of a method of subjecting the refuse matter of these substances to a process, whereby it is rendered available for other useful purposes. The inventor states that the oil possesses three different characters, viz., essential oil, intermediary fat oil, and thick oil, and which SPECIFCATIONS OF RECENT ENGLISH PATENTS. re separated by the following methods. The schiste, after having been cleaned, reluced to powder, and sifted, is put into a eservoir placed over the end of a retort. Between the reservoir and the retort is an ron box with two doors, one at the top communicating with the reservoir, and one at the bottom communicating with the reCort. When the schiste is placed in the reservoir, the upper door is opened to allow it to descend into the box; the lower door is then opened to allow it to pass into the retort, the upper one being closed to prevent the escape of the vapour. In the retortwhich is a circular pipe-is placed an Archimedean screw, by turning which the schiste is drawn forward; heat is then applied at the end of the retort until the temperature reaches 100° Reaumur, when essential oil will rise in vapour through a vertical tube placed near the end of the retort, and thence through other tubes into a condenser where essential oil is obtained. The charge having been subjected to this temperature for half an hour, the workman passes it by the application of the screw, farther along the retort, where it is then subjected to a heat of 200° Reaumur; by this increased heat the vapour is given off as before through a separate tube placed near the centre of the retort, thence through other pipes into another refrigerator, where the intermediary or fat oil is obtained. After having subjected the charge to this temperature for about half an hour, the workman again pushes the charge on to the further end of the retort, where it becomes of a red heat, and the vapour given out passes, as before, through its separate tubes, into another refrigerator yielding the thick oil. Every time the workman propels the schiste forward he opens the doors of the reservoir, so that the process is continued in its different stages without interruption. The refuse is passed on to the end of the retort, from which it falls into a box beneath, where it is left to cool. As asphalte becomes liquid by the application of heat, it requires a different treatment from schiste, and the difficulty of distillation is considerable, because the bottom of the retort becomes covered with charcoal. To effect the distillation the inventor uses small iron retorts placed in a reverberatory furnace, so that the heat may act upon them on all sides. Each retort is 12 feet long, and 1 foot in diameter, and contains from two to three hundred pounds weight of asphalte. Five retorts are placed horizontally in one furnace, which is of a semicircular form. The projecting end of each retort has an ascending and descending tube attached thereto; the ascending tube conducts the vapour containing the most volatile oil into another tube whence it passes into its condenser; 255 the descending tube conducts the vapour containing thick oil into another condenser. For obtaining essential oil from asphalte a heat of 130° Reaumur is necessary, and for thick oil 250°. The refuse of the carbonized asphalte is a hard black coal, which may be employed for the same purpose as the refuse of the schiste. Thus two oils are obtained, viz., essential and thick; to obtain the intermediary, the thick kind is subjected to distillation in iron retorts, by which means the intermediary is separated from the tar, which is very fine, and can be employed in the preparation of varnish, and for all purposes where the bitumen of India is now used. The third part of this invention relates to a method of rectifying the oil thus obtained for manufacturing purposes. The fat oil is subjected to a pressure of steam, by which means any essential oil that may remain will be forced out, and any empyreumatic smell removed. The oil thus prepared requires to be passed through an ordinary filter, and is then ready for application to all kinds of machinery. The essential oils obtained by the different temperatures may be used as solvents for caoutchouc, the manufacture of varnishes, the preparation of colours, and other similar purposes. The aci The fourth part of the invention relates to the treatment of the refuse arising from the several operations above described. The ammoniacal water formed in the distillation of the schiste is used in the manufacture of ammonia by the ordinary means. dulated tar will be found applicable to the production of the sulphate of soda, &c., by an addition of chloride of sodium in the ordinary manner. The coal or carbon, which contains pyrites when taken from the retorts, is placed in closed boxes to prevent the contact of the air, which whitens it; when cold and well dried, it is placed for twenty-four hours in a leaden vessel with water acidulated with sulphuric acid, which penetrates through all the pores, and attacks the iron; after having soaked twenty-four hours it is washed with cold water until no trace of the acid is left; it is then subjected to renewed carbonization; the refuse thus recarbonized is withdrawn, broken, reduced to powder, and sifted, and may be employed as a discolourant in sugar refinery, as a manure, and as a black colour. GEORGE WILDES, COLEMAN - STREET, LONDON, for improvements in the manufacture of white lead. Enrolment Office, March 4. The lead is melted and poured through a metallic sieve into water; 200lbs. weight of the lead thus granulated is then placed in a hexagonal or square tub of wood lined with sheet lead. A hollow axis goes through the centre of this tub, and revolves with it; at |