INQUIRIES-ANSWERS TO INQUIRIES. more or less, according to the size of the vessel, thus filling a space of perhaps three feet and a half on each side; and though, by being placed lower, it probably would not increase the width of the vessel more than paddle-wheels now do, yet that circumstance would render it inconvenient in difficult navigations, and may much restrict its use in rivers and canals, though I do not apprehend that this will be a material objection to vessels navigating on the sea. A second objection may be founded on the velocity of the rotatory motion required to produce a given pro gressive motion. It is easily perceived, that the progressive motion acquired in one revolution of the spiral wheel cannot exceed the distance of its threads from each other, but must indeed be somewhat less, owing to the yielding nature of the water; whilst that obtained by one revolution of a paddle-wheel bears a great proportion to its circumference but this objection, I think, will be overbalanced by the diminished force required to turn the spiral wheel, and the small proportion of it that will be inefficient. I will not trouble you with any farther observations, my object being to draw the attention of your Correspondents to this subject, for the 15 engine; or, in other words, what increase in the diameter of the cylinder will compensate a decrease in the stroke? For instance, a cylinder of 24 inches diameter, with a stroke of five feet, equals about 20 horse power; what diameter of cylinder is required if the stroke is only thrée feet? Blackfriars-road. X. NO. 113.-COMPARATIVE COST OF SIR,-I should be thankful to any An Old Correspondent, 17th March, 1825. XX. purpose of ascertaining its practica- ANSWERS TO INQUIRIES. bility. If you think the suggestion worth publicity, a page of your very useful Magazine will oblige, NO. 110. ELECTRIFYING MACHINES. SIR,-Your Correspondent," Junior," may make his caps of wood or brass. I have turned one pair out of box-wood. The cement for fixing them on the necks of the cylinder, is made by melting equal parts of rosin and bees-wax, and one-fourth of their weight of red ochre. It will be necessary to drill a small hole (longitudinally) through the cap that is first fixed (which may be done while the cap is yet in the chuck), to suffer the air in the cylinder to escape, which the heat of the cement will cause to be rarefied, on fixing the second cap, otherwise the cylinder will be in danger of being burst to pieces. The rubber consists of a cushion, stuffed evenly with curled 16 ANSWERS TO INQUIRIES-CORRESPONDENCE. hair, a little concave on the face, I.am, Sir, yours respectfully, Brook-street, Ratcliff. NO. 89. CHESS-MEN. SIR,-I beg leave to send Inquisitor a Composition to make his Chess-Men of: I must state, at the same time, that I have not made a trial of it, though I think it will answer the purpose. close up with paper; dry it by a gen- M. NO. 80.-NEW IMPERIAL MEASURE. SIR, I send you, in answer to T. H.'s proposition (Number 80, p. 382), the following inside dimensions of the Quart, Pint, and Halfpint; also the thickness of metal of the top and bottom, and thickness of the bottoms, all in inches. I must beg leave to observe, that T. H. says, "the top diameter and perpendicular depth of each to be equal to the bottom diameter in proportion to the top as 7 to 10;" whereas, 1 presume, he means the top diameter and perpendicular depth of each to be equal, and the bottom diameter in proportion to the top as 7 to 10. Your constant Reader, Take fine saw-dust of lime-tree B. C. TopDiam. Bottom Thickness of Diameter. Bottoms. 3.46134 0.64262 0.44984 1.28525 Content. 69.3185 Pint Half-pint 3.92466 2.74726 CORRESPONDENCE. We long to hear from T. R. L. J. A. Whitfield will please transmit the plan he has in contemplation. Communications received from-Double Escapement-Mr. Monnom—G. W, -A. B.-W. H. S-e-B. H.-C. G.Mr. Hall-A Resident at Lee-Islington-Phaeton-A Child-H. A. D.~ A. M. F. P.-Mr. Lake Trebor Valentine-A Foremastman--P. Q.-T. Mason-Lux-M. R. Mr. Speer's letter came too late to have a place in our present Number. It shall appear in our next. Two or three other papers intended for insertion this week, are unavoidably deferred. Communication (post paid) to be addressed to ་་ Mechanics' Magazine, MUSEUM, REGISTER, JOURNAL, AND GAZETTE. No. 86.] SATURDAY, APRIL 16, 1825. [Price 3d. "Science clears the obstructions which impede the progress of Art, and Art adorns and smooths the path of Science. No discovery is made without some previous conjectural effort of the mind, some exertion of the imagination; nor is any beauty unfolded where there has not been some preconsideration of probable effects, some exertion of the reasonable faculties."-Ferro. SIR, The drawing and description, &c. of a Washing Machine, which I take the liberty of transmitting herewith, I shall be glad to see inserted in the Mechanics Magazine. I am, Sir, Yours respectfully, J. ARMSTRONG. Northumberland House Academy, Norwood. VOL IV. Description. A is the washing-trough, supported upon four legs, BBBB, by two iron straps, screwed through the legs, by the nuts, CCCC; at the end of the trough is a a; the legs are let into the frame, cock, G, to carry off the soap suds; in the trough is a washer similar to F, perforated with holes, and borne by the beam, H, upon the cross bars, hh, by the spindles, aa. Upon the beam, H, are two iron pillars, EE, with a joint C near the beam, H; on each side of the iron pillars are strong springs, DD, of four or five leaves, set very proud at the top against the iron pillars, and bolted together at the bottom upon a stout piece of irou. The tops of the iron pillars are attached by a bolt to the beam, I, of the crank, J; and upon the axle-tree of the crank is a tooth-wheel, K, turned by a small pinion, L, upon the axle-tree of the fly-wheel, M, which is turned by the handle, N. If a machine upon this plan be made with a trough three feet long, and the pinion, L, to revolve three times for the wheel K's once, it will first fourteen or sixteen gentlemen's shirts in fifteen minutes, and second them in five minutes, making in all but twenty minutes, and the machine may be turned by a boy of ten or eleven years of age, as it would require no more strength than one of Mr. Baker's patent mangles. The inventor of this machine does not assert that the whole is original; a trough and washer similar to this he saw when a boy at school, but all the rest is original. He has made two machines upon this principle, the second having some improvements upon the first, and they both answer well when properly managed. This machine would be found most valuable where there is much washing; it is simple, and easily managed when there is a will that it should answer the purpose; but if the use of it be left to careless servants, or washerwomen, the machine, in such cases, will have to bear the blame of bad washing; whereas, when used with even moderate skill, it will wash more linen in six hours than six women can wash in twelve hours. of the same thickness or quantity; for, if linen be laid thick in one place and thin in auother, the thick part will be cleansed, and the thin but little. Ladies' dresses, laces, caps, and any thing delicately fine, should be put into a porous linen bag, or a fine meshed net (indeed, if all small things were put into a small meshed net, so much the better, as it would prevent them being entangled by being washed over the top of the washer), then no accident can happen to the linen. When you have put your linen into the machine, pour upon it as much of the dissolved soap as may be deemed necessary to cleanse the quantity of linen in the machine; then pour in the water or soap suds, boiling hot, and after you have fixed your cover on the trough, turn the machine for one quarter of an hour, and your linen will be cleansed, unless it is very foul indeed, in which case a little more time must be allowed; then take the linen out, and at the same time draw off the soap suds, and charge your machine as before. Whilst the machine is washing the second charge, get your cleansed linen wrung and the soap suds boiled,, ready for the third charge; and when you have gone through the firsting of all your linen in this manner, commence and pursue your secondfive minutes for each machine full. Be ing in the same manner, allowing about sure never to put any dry foul linen into the machine, as the boiling liquor will fix the dirt, which will never afterwards be wholly eradicated this is a very common error in cleansing linen, where machines or washing-dollies are used. One of these machines may be seen by applying at Mr. W. Richards's, measuremaker, No. 16, William's-court, Great Guildford-street, Southwark, London. The savings of this machine aretwo-thirds of the usual time, half the usual fire, soap, and, what is very desirable, the linen; for the machine does not wear the, linen a tenth part so much as the hands, neither does it tear the linen. One has been in use for eight or nine years, and it has never been known to tear or injure any thing, although it has cleansed the most delicate parts of dress. This machine may easily be made to wash in any pressure of steam; and if constructed for that intent, it would (in the humble opinion of the inventor) far surpass any steamwashing machine yet made; for without pressure linen cannot be cleansed in any moderate time, and cylindrical wheels, revolving in a case, may, ADVICE TO STAMMERERS-BROWN'S GAS VACUUM ENGINE. by the linen constantly falling from the centre, chafe the cloth nearly, if not quite as much as the hands. One proof that this machine does not wear the linen is this: if you put in stockings with holes in them, the holes will not be in the least enlarged by the machine, nor will it make holes in thin places; where linen, on the contrary, is cleansed by chafing, and not pressure, enlargement of the holes in stockings, and holes made in thin places, are sure consequences; this is a fact known to every domestic female. Should any person or persons wish any farther information, with respect to the mechanical construction of this machine, either to wash in a pressure of steam, or otherwise, it will be cheerfully given, on addressing a line to J. Armstrong, Northumberland House Academy, Norwood, Surrey. for ADVICE TO STAMMERERS. It has been observed, in regard to stammerers, or those who have a defective utterance, that they can sing, or even read, without hesitation, although they cannot speak. What is the rationale of this fact? It will be found to depend on the following principle: Continuous muscular action is far more easily effected than that which is interrupted. This principle is even general in physiology. It has been remarked, that a drunken man, or a person affected with that disorder termed St. Vitus's dance, can run, though he cannot walk, or stand still. In the same manner, a stammerer can sing, which is continuous motion, although he cannot speak, which is interrupted. Continued muscular motion is also attended with less fatigue than that which is interrupted; and this is particularly observed in regard to speech. It is on this account that there is a tendency, in those who speak much in public, to acquire a sort of sing-song mode of delivery, which it requires good taste and con stant exertion to correct. It is on this account, too, that those who cry in the streets, actually acquire a sort of tune, or cry, as it is termed; the 19. continued action of the muscles of speech being so much more easy than the interrupted. The same is constantly observed in children on their first attempts to read. Let a stammerer, then, observe this rule :—Always to speak in a continued or flowing manner, avoiding carefully all positive interruption in his speech; and if he cannot effect his purpose in this manner, let him even half sing what he says, until he shall, by long habit and effort, have overcome his impediment; then let him gradually, as he may be able, resume the more usual mode of speaking, by interrupted enunciation. It is understood that this is the principal means employed by those gentlemen who have undertaken to correct impediments in the speech, and it is undoubtedly the most rational. In addition to this rule, let the stammerer endeavour to speak in as calm and soft a tone as possible; for in this way the muscles of speech will be called least forcibly into action, and that action will be least liable to those violent checks or interruptions in which stammering appears to consist. It is scarcely necessary to remark that there are other inducing causes of stammering, such as nervousness, which must be cured by different means. Of these it would be necessary to treat in an essay written expressly on this interesting subject. BROWN'S GAS VACUUM ENGINE. We are informed that Mr. Brown has tried his engine with a piston, and that it is found to answer his most sanguine expectations. A Company, we perceive, has been formed for applying this engine to the purposes of boat and barge navigation. They have begun by offering a premium of one hundred guineas for the best model, exemplifying the power when applied to the head, stern, or sides of a vessel, both in shallow and deep water, in canals and rivers. A premium of thirty guineas is also to be given for the second best, and twenty for the third best models. |