HUTCHISON'S IRON TALLY-MAN. Sir, I have the pleasure of communicating to you a drawing and description of an ingenious and useful machine-the Numeroatus-matured from the fertile genius of Mr. Hutchison. It is an iron clerk or tally-man, whose business it is to register the amount of coals, &c. that are landed, from time to time, on the wharf belonging to the London Gas Company at Vauxhall, and for which service they used on previous occasions to employ two clerks. The following is a description of the engraving which, no doubt, will be read with interest by your numerous subscribers : The object of this machine, as before stated, is to register the number of waggons which are raised in a day by the coal-hoisting apparatus, and which it registers on the dial A, fig. 1, to any number not exceeding 200. This is effected by the waggons giving motion, in their passage from the barges to the platform, to one of the two levers ab, which they perform just as they arrive at the surface of the stage. As the machine is represented in the drawing, a, fig. 2, will be the lever first acted on. The waggon as it arrives at the surface of the platform comes in contact with the lever a, which it will raise, and cause the tooth-segment c, lever b, and weight d, to revolve in the same direction until the weight d gets a little past the centre of the spindles, when the waggon begins to descend, leaving the weight to continue the motion in the same direction, until it has exactly passed through the tenth of a revolution, when the end of the lever b will be depressed to the level from which the lever a was raised, and in which position it remains until the next waggon is brought up, when it puts in action the weight, tooth-segment, and lever a, in the manner before described. The tooth-segment c puts in motion another tooth-segment e, which is fixed to the spindle f; this spindle is continued through the bevel-wheels g h (which are not fixed to it), loose collar i, and ratchet-wheels kl; these ratchetwheels are fixed to the spindle f, and turn with it. On the back of each of the bevel-wheels g h is fixed a catch m, which is kept into the teeth of the ratchet-wheel by the spring n; when the lever a is raised, the ratchet k carries forward the wheel g the tenth of a revolution, the wheel g acts on the wheel o, which is in gear with the wheel h, and causes it to revolve in the opposite direction to g, which it is enabled to do in consequence of its not being fixed to the spindle, and the teeth of the ratchets being cut in opposite directions; on the contrary, when the lever b is raised, the ratchet / moves the wheel h, which causes the wheel o to revolve in the same direction as when the lever a acted on the wheel g, and which will now be driven in the opposite direction to the wheel h by the wheel o; the wheel o is, therefore, caused to revolve the tenth of a revolution every time either of the levers a or b are acted on by the waggons, and is fixed on the spindle p, which passes through the hollow spindle q, on which is fixed the hand r; the hand s is fixed on the spindle p, and is carried on, the tenth of a revolution every time a waggon is landed on the platform, as before described. The dial A, fig. 1, it will be seen by the engraving, is divided on the outer circle into ten divisions; and as the hand s, fig. 2, is carried forward the tenth of a circle, or one of these divisions, on the landing of every waggon, ten waggons will cause the hands to complete one revolution, and any number less than ten will be registered by it, and all above that number by the hand r, which is acted on in the following manner:- -On the spindle p is a pinion t, which acts on the wheel u, fixed on a spindle v, on the other end of which is a pinion w, acting on a tooth-wheel x, fixed on the hollow spindle q; the teeth of these wheels and pinions are so arranged, that the hollow spindle q, with its hand r, make exactly one revolution, while the hands makes twenty; the hand r is shorter than the hand s, and points to an inner circle on the dial, which is divided into twenty parts. The hand r passes through one of these divisions for every ten waggons raised, two for twenty, and so on to 200. B, fig. 2 is a circular iron box to contain the wheels, and to protect them from injury. C is a stay to support the bearings. DD, fig. 3, two steel stops, which prevent the levers a and b, in conjunction with the weight d, from causing the lever E and spindle_f, fig. 2, to revolve Sir,-It is painful to reflect upon the injurious consequences to the health of a numerous class of society resulting from the contracted position in which a tailor perform his work; and when it is considered that it is not one of those insur mountable evils attendant on some callings, but is the result of indifference, it becomes, I think, a duty we owe to our species to endeavour to remove or alleviate the evil. I have been induced (from a trial made for some years whether the work could be executed in all points by any other me thod than sitting cross-legged, as it is termed) to construct the work-table a drawing of which accompanies this article, the design of which is, to the best of my knowledge, perfectly new. This work-table is designed for a person to sit to, it being but two feet from the ground to the under side of the board. Description. aaaa, is a firm-made frame of wood, two inches thick, to hold the revolvingboard b, which is for the purpose of suiting any light; it is of wood, one inch thick, and revolves with ease and firmness on an inch projection of the outer frame c; the opening where the workman sits is in the model eighteen inches wide, but may be made any size without affecting the principle. d, the board, which exactly fits the opening. ee, the blocks, holding the cushions, which are wide and flat, for the purpose, when extended along the slide f, of holding the sleeve-board when pressing, and when placed together, as in the engraving, form an appendage to the sewing-cushion g, which has an octagonal plug, made to fit a hole in the board between the cushions for pressing, a small distance from the centre, fastened by a screw to the under part of the block, on which it (the cushion) is fastened; by which double means it can be made higher or lower, or the position altered, to suit the taste or convenience of the workman. hh, the iron, receiving the bolt, having a hinge-joint in it, by which simple method the board may be turned into the opening, or lifted up and removed altogether, in an instant, for the purpose of basting large things. i, the entrance-door. I am, Sir, yours, &c. T. R. CROFT. 19, Moscow-road, Bayswater. M. GUESNEY'S NEW GEOLOGICAL THEORY. Sir, I promised in my letter, No. 686, to make some remarks on the communication of an "Old Correspondent" (No. 682), relative to M. Guesney's new system of geology. I observe that another correspondent (O. N.) has given a solution of a question taken from Leadbetter's "Astronomy," in which he (O. N.) attempts to prove, from the said solution, that in the year 15064, London will be in the latitude of 81° 3′ 11′′ N., and Edinburgh in 76° 37′ 11′′ N.; and, consequently, Edinburgh will be 4° 26' south of London! From Leadbetter's calculation it appears, that the distance of Polaris in the year 1727, was 5o. 14′ 29′′ short of the tropic of Cancer, the latitude of the star then being 66° 4' 11" N., and its declination 88° 33′ 11′′ N.; and assuming the distance between the tropics sof Cancer and Capricorn to be 46° 58′, then 88° 33' 11"-46° 58′ 42°35′ 11′′ N. will be the present pole's declination when in Capricorn; and 51° 32'-420 35 11" 8° 56′ 49" will be the distance of the pole star south of the zenith of London in the year 15064. Some corrections might be made in the above calculation from our present improved astronomical tables; but the principles are correct, and the results are nearly true. But there is one part of the calculation, which is that of finding the latitude of London by having the zenith distance and declination of the star given, on which I must offer a remark. Does Leadbetter, in his Astronomy," Mr. O. N., direct you to subtract the zenith distance from 90° to give the latitude of the place of observation? I am certain I may answer the question myself by saying, No. So that (90°-8° 46′ 49') 81° 3′ 11′′ N. being the latitude of London in the year 15064, is obtained by a rule of O. Ñ.'s own invention. Indeed, by the same rule we might make London to be in any latitude we chose to assign it, by selecting particular stars for that purpose. But Leadbetter's own calculation shows the absurdity of O. N.'s rule; he calculates that the declination of our present North Pole star will in the year 15064, be 42° 5' 11" N., and that the distance of the same star will be 8° 56, 49" south of the zenith of London, or the zenith of London will be 8° 56′ 49′′ north of the said star. Now, every one acquainted with this simple part of astroncmy knows that the sum or difference of the declination and meridian zenith distance of any of the heavenly bodies gives the latitude of the place of observation. Hence 42° 5' 11"+ 8° 56′ 49′′ = 51° 32′ N. will be the latitude of London in the year 15064, the same as it is at present. It, therefore, appears that your correspondent, O. N., has fallen exactly into the same error that M. Guesney has done in the description of his geological globe, communicated by an "Old Correspondent." In conclusion, it may be stated, that the perfect agreement of the latitudes of places deduced from ancient and modern observations, fully establishes the fact, that the earth has always continued to revolve upon the same axis, and that the changes that take place in the right ascension and declination of the fixed stars is caused by a change of position of the earth's axis. It is true, if the moon were to strike the earth, which Mr. Mackintosh predicts will ultimately be the case, it would cause the earth to revolve upon a new axis, and thus would cause an instant change in the latitude of places. But so long as Kepler's laws hold true, no danger can be anticipated from such an event ever taking place. I am, Sir, yours, &c. Sir, I herewith forward you a description of a machine which was constructed by me in the year 1823, with a view to produce a perpetual motion. With this machine, and the studies necessarily connected with it, first originated the suspicion that the planets could not continue in motion unless they gradually b approached the centre of attraction. In the first place, let us describe the machine. Fig. 1, A, is a sectional view of the interior of the wheel, which is "formed in two halves upon one shaft; "each half or section is furnished with a projecting ledge, and an opening is left between the two ledges sufficiently wide to admit of a magnet being introduced between them. By which arrangement the magnet may be brought as near to the ball as may be necessary (see fig. 2.) Bisa magnet, whose line of attraction acts at right angles with the line of gravity. C is an iron ball, under the action of two forces. The magnet continually drawing the ball up the inclined plane within the wheel, and gravity continually drawing it to the bottom, by their united action it was supposed the wheel would revolve for ever, or till it was worn out; upon the same principle that a wheel revolves by the animal force or muscular action of a mouse or squirrel, which carries it up the inclined plane, whilst it is continually drawn to the bottom by the action of gravity, thereby causing the wheel to revolve by the weight of its body. The model was taken from the earth's motion round the sun; and the following process of reasoning seemed to justify the assumption that the wheel would move on till it was worn out;"The earth is carried round the sun by the action of two forces, one of which is momentum, which is not, in reality, a force or cause of motion, but an effect derived from an original impulse; and that impulse, or the momentum derived from it, is not destroyed, because there is. no resistance to the moving body, that is, there is no friction. Well, I cannot make this machine without having resistance to the motion, that is, friction; but to compensate for this, I have two real forces, two causes of motion, each of them capable of imparting momentum to a body; they are both constant forces; and from one of them, the magnet, I can obtain any power that may be required within certain limits." This reasoning appeared conclusive, and the wheel was made; but when the magnet was applied, instead of the ball rolling up the inclined plane, the wheel moved backwards upon its centre. It occurred to me, that by placing a small ratchet upon the wheel, as shown at D, this backward motion of the wheel on its centre might be prevented, in which case the ball must roll up the inclined plane, and that a perpetual motion might then ensue; but this ratchet I never tried, having about that time begun to perceive that the idea of a perpetual mechanical motion, either on the earth or in the heavens, involves an absurdity-and that, therefore, the motions of the planets must necessarily carry them continually nearer and nearer to the centre of attrac tion. However, if any of the readers of the Mechanics' Magazine should feel disposed to try what can be done by adding the ratchet, I hope I have stated the principle plain enough to enable them to proceed. Your obedient servant, Sept. 1836. THOS. S. MACKINTOSH. MESSRS. SYMINGTON AND HOWARD'S SYSTEMS OF CONDENSATION. Sir, I might perhaps be well satisfied to let the correspondence in your journal between Mr. Symington and myself remain as it is; but one word more. Mr. Symington, I regret to notice, has swerved, more particularly in his last communication, from a fair disputation of the subject, and descended to almost personal scurrility. Nevertheless, with him self I would willingly adopt the suaviter in modo; but with the subject I shall not abandon the fortiter in re. When, therefore, I find any persons practising condensation by "the withdrawal of the warm water from the vessel in which the steam is condensed, and injecting it again amidst the steam, the heat in the mean time having been abstracted from the water," or, according to Mr. Syming ton's version, "by cooling down the water in the hot-well to the temperature of the external water, in order that condensation may be effected by injecting, again and again, a portion of the same water"-I shall deem such a direct infringement on the process set forth, and which has been fully realised in practice, under my patent, and shall, of course, act accordingly. The position of the refrigerating-pipe, or other surface, as duly noted in the specification, matters not. In the Vesta a still is added to each vaporiser, and its refrigerating-pipe is placed outside the vessel, exposed to the wash of the paddles, by which means a supply of very pure water is obtained for the use of the engines, &c., and the salt is prevented from accumulating in the stills by allowing a small stream of water to run from the lower part of them into the ash-pit, which at the same time cuts off the communication of the heat from the ship's bottom. But the distillation of sea-water not being my invention, I consider such details or petty arrangements as altogether unworthy of a patent; and yet Mr. Symington's external refrigerating-pipe bears precisely the same relation to the process of condensation just described. Lastly, excepting the position of this pipe, the points of difference noted by Mr. Symington have already, as I before informed him, been put in practice in the Vesta, and are, in fact, but parts of the ordinary plan of condensation, and not at all new in themselves, as Mr. Symington must be well aware. Thus taking leave of a discussion drawn out to a greater length than many, or perhaps most of your readers may approve, Your most obedient servant, THOMAS HOWARD. 7, Tokenhouse-yard, Nov. 22, 1836. |