SCIENTIFIC GLEANINGS. present defective construction of the machinery, and will be corrected as the makers of such carriages gain greater experience. Admitting even that the present engines do work with some noise, the effect on horses has been greatly exaggerated. All the witnesses accustomed to travel in these carriages, even on the crowded roads adjacent to the metropolis, have stated that horses are very seldom frightened in passing. Mr. Farey and Mr. Macneil have given even more favour. able evidence in this respect of the little annoyance. No smoke need arise from such engines. Coke is usually burned in locomotiveengines, on railways, to obviate this annoyance, and those steam-carriages which have been hitherto established also burn it. Their liability to be indicted as nuisances will sufficiently check their using any offensive fuel. There is no reason to fear that waste steam will cause much annoyance. In Mr. Hancock's engine it passes into the fire; and in other locomotive-eugines it is used in aid of the power by creating a quicker draught and more rapid combustion of the fuel. In Mr. Trevithick's engine it will be returned into the boiler. The Committee not having received evidence that gas has been practically employed in propelling carriages on common roads, have not considered it expedient to inquire as to the progress made by several scientific persons who are engaged in making experiments on gases, with the view of procuring a still cheaper and more efficient power than steam. The Committee having satisfied themselves that steam has been successfully adopted as a substitute for horse-power on roads, proceeded to examine whether tolls have been imposed on carriages, thus propelled, so excessive as to require legislative interference, and also to con sider the rate of tolls by which steam carriages should be brought to contribute in a fair proportion, with other carriages, to the maintenance of the roads on which they may be used. They have annexed a list of those local Acts in which tolls have been placed on steam or mechanically-propelled carriages. Mr. Gurney has given the following specimens of the oppressive rate of tolls adopted in several of these Acts :-On the Liverpool and Prescot-road, Mr. Gurney's carriage would be charged £2. 8s., while a loaded stage-coach would only pay 4s. On the Bathgate-road, the same carriage would be charged 1. 7s. Id., while a coach drawn by 4 horses would pay 5s. On the Ashburnham anu Totness-roau Mr. Gurney would have to pay £2., 399 while a coach drawn by 4 horses would be charged only 3s. On the Teignmouth and Dawlish roads this proportion is 12s. to 2s. Such exorbitant tolls on steam-carriages can only be justified on the following grounds: First, because the number of passengers conveyed on, or by, a steam-carriage will be so great as to diminish (at least to the extent of the difference of the rate of toll) the total number of carriages used on the road; or, secondly, because steamcarriages induce additional expense in the repairs of the roads. The Committee see no reason to suppose that, for the present, the substitution of steam-carriages, conveying a greater number of persons than common coaches, will take place to any very material extent; and as to the second, of increased charge, the trustees, in framing their tolls, have probably not minutely calculated the amount of injury to roads likely to arise from them. The Committee are of opinion that the only ground on which a fair claim of toll can be made, on any public road, is to raise a fund, which, with the strictest economy, shall be just sufficient-first, to repay the expense of its original forma, tion; and, secondly, to maintain it in good and sufficient repair. might, by rendering the gelatine and fat of the bones available, snpply 30; or, in other words, four oxen would furnish as much alimentary substance as is now ob tained from five. 2. Toothache-Dr. RYAN. Dr. Ryan, in the London Medical Journal, Vol. ii., p. 56, strongly recommends the nitric acid, as affording almost immediate relief in toothache. The best mode of employing it, is by means of lint wrapped round a probe, and moistened with the nitric acid, which is then to be carefully applied to the cavity of the tooth. - 3. Marking Linen -M. HENRY.Journ. de Pharm. 1831, p. 388. M. Henry recommends the following process as the best for marking the linen of hospitals, &c. in a perfect and durable manner, so as to resist alkalies, soap, &c. One part by weight of iron-filings, and three parts of vinegar, or acetic acid of 1056 spec. grav. Mix the filings with half the vinegar, and agitate; as it thickens, add the rest of the vinegar, and also one of water. Then apply heat; when all the iron is dissolved, add three parts of sulphate of iron, and one of gum arabic, previously dissolved in four parts of water; when to be used, the linen is to be spread on a table, and the preparation applied by means of a hair-brush and stencil plates of copper. 4. Prevention of Falsification of Writ ten Instruments. The Academy of Sciences of Paris appointed a Committee, consisting of M.M. Gay-Lussac, Dulong, Chaptal, Deyeux, Thenard, D'Arcet, Chevreuil, and Serrulas, at the desire of the French Government, for the purpose of finding some means of preventing writing being chemically discharged from papers, and other documents, either for the purpose of falsifying the contents, or for making a second and fraudulent use of old stamps. On the 6th June, M. D'Arcet read a Report to the Academy, of which it will be sufficient to state the conclusions. The Committee found that the falsification of written documents will be fully prevented by the use of ink prepared in either of the two following manners: 1. Indian ink (or, in its absence, the imitation of it made in Europe, with soot, and animal glue, or gum) dissolved in a mixture of water, and muriatic acid of 1010 sp. grav. The ink may be prepared for 4d. per quart. 2. To a solution of acetate of manganese, of 1074 sp. gravity, add half its weight of solution of carbonate of soda crystallized; dissolve Indian ink in the liquid, and writing traced with it will become perfectly indelible on being exposed to the action of the vapour of liquid ammonia. The Committee lay down as a general principle, that no ink, kept in a liquid state, can be indelible ; as the colouring matter, from its excess of density, will necessarilly be deposited. 5. Destruction of Weeds by Sulphate of Lime. 100 lbs. water, 20 quick lime, 2 flour of sulphur, boiled in an iron vessel. Dilute the clear solution, and use for watering alleys and pavements. 6. Defence against Flies. It is said, that the butchers of Geneva have, for a long time, used the oil of laurel as a substance, which prevent flies from approaching meat.-Recueil Industrielle, xv. p. 247. 7, Native Country of the Potato.-Mr. CRUIKSHAN KS. In Dr. Hooker's Botanical Miscellany, Mr. Cruikshanks proves that this important vegetable is really indigenous to Chili. T. H. B. Feb. 3, 1832. INTERIM NOTICES. Philo-Mechanicus's friendly letter, has reminded us of our having omitted to say, that we shall be glad to hear from him again on the subject which formerly exercised his pen. Communications received from Pro Bono Publico-Dunbar-Philo-Fair Play-A Female Reader -Mr. Mackinnon-R. S. LONDON: Published by M. SALMON, at the Mechanics' Magazine Office, Wine-Office-court, (between 145 and 146) Fleet Street, where Communications (post paid) are requested to be addressed. Sold by G. BENNIS, 55, Rue Neuve, St. Augustin, Paris. GRAY and BOWEN, Boston (U. S. M. SALMON, Printer, Fleet Street. OF COUNTING MACHINE, INVENTED BY MR. Sir,-At the desire of my brother, Mr. George White, Glasgow, inventor of the new power-loom, &c., of which an account is given in your 424th No., I send you for publication a description of a Counting Machine, which he has invented. The accompanying drawing exhibits a horizontal view of the machine. It consists of an upper frame-work A, and a lower B, connected by the four pillars or feet, H H H H (not, of course, shown in this bird's-eye view). Between the two parts of the frame-work is placed a wheel C, which works into the pinion E. To the pivot of the wheel C there is attached an arm P, which points to an outer circle S S, on which should be engraven as many numbers, in regular succession from 1 to 500, or more, as it will conveniently hold. D is a quadrant screwed to the upper part of the frame A, and on which the numbers 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, are engraved. When the operator is going to commence the addition of a sum, he places the pointer of the index at o, and putting his finger on the arm of the pinion, which points to the first figure of the sum, he brings it down to the stop at o; so many teeth of the wheel are turned, and, of course, the pointer will point to as many, or as great a number on the outer circle S. Suppose the sum to be added were 345967910219, the operator, after having placed the pointer of the index at o, puts his finger on the pinion pointer at 9, which is the first figure in the sum, and brings it down to the stop at o. Then, the second figure, which is 1, and of course only one tooth is turned. Then, the third, which is 2; the fourth, which is 10; and so on to the last, as fast as the fingers can move them, when the index pointer will be found to stand at 65, the sum total of the question. If it be pence which the operator is summing, the index pointer at every twelfth digit, will turn out a small hand, on which is engraved 1, that is one shilling; and at the second twelfth digit, 2 shillings, and so on to the end of the sum. If it be any other sum than money upon which the machine is operating, these lesser hands are turned out of the way of the pointer by a screw in the index cir cle, and another set turned in by the same means to divide the whole into as many parts as the nature of the division requires. In performing by the machine, it will be observed that the accuracy of the product is certain. The machine, too, is simple-merely a wheel and pinion-it is convenient and expeditious, and not expensive. In heavy columns, as of numbers of yarn in mills, and in deep sums, as in large pay sheets, it will be found exceedingly useful. The whole will be summed up as quickly as it can be read, and thrown into pounds, shillings, and pence; or into other divisions, according to the nature of the sum, in one operation. It will go through more work under the guidance of a clerk, than the clerk can do alone; and what is of much importance, it will not require from him so much attention. He will. not, indeed, have the least occasion to be anxious about the result. In cases where the sum is great, it may far exceed the number on the index circle, and to meet cases of this sort, two or three index circles should be attached to the machine-the one placed outside of the other, and the numbers continuous from the one to the other. The index pointer should be of two pieces (telescope-wise) formed so as to extend out to describe the circle to which it is pointing. Yours, &c. J. WHITE. London, Oct. 13, 1832. [We venture to pronounce this an excellent invention. To shopkeepers, and all persons liable to frequent interruptions, a machine by which they may add up sums of any amount, with infallible accuracy, without the least aid from memory, and may stop in any part of the process, without ever having to retrace a single step, must be invaluable. An enterprising speculator might, we think, make a fortune by manufacturing such counting-machines for sale; and if he were, at the same time, an honourable man, he would not leave the ingenuity which contrived them, to go unrewarded. The description is not, in some parts, as distinct as we could have wished-that which regards the minor arms or divisors especially; but the principle of the invention is so clear, that no expert mechanic could be at any loss to give it the largest possible practical application.-ED. M. M.] LONDON AND GREENWICH RAILWAY. When we first saw the project of this railway announced, we thought its success, as a pecuniary speculation, extremely questionable; first, because the traffic in goods between London and Greenwich is inconsiderable; and, secondly, because persons could not, with THE ARCANA OF SCIENCE FOR 1832. out great difficulty and inconvenience, avail themselves of it, for the transport of goods to or from such shorter distances as Rotherhithe, Bermondsey, or Deptford. From the explanations we have since received, however, we are inclined to entertain a very different opinion. The railway is not intended to be opened for the transport of goods at all. It is to be exclusively devoted to the conveyance of passengers; and if the statements we have before us are correct, there is every reason to believe that from this source alone an ample revenue will be obtained. It appears that the number of passengers between London and Greenwich annually is, on an average, not less than two millions; a fact almost incredible, but accounted for by the great number of citi zens who resort to Greenwich Park and Blackheath during the summer season, for purposes of health and recreation. That there would be a vast accession to this regular supply of metropolitan visit. ors, when persons could enjoy the additional pleasure, and great novelty, of riding to and fro in a steam-carriage, there can be no doubt; perhaps were we to take credit for another million on this account, we should not exceed the bounds of probability. Here, then, we have a constant supply of three millions of passengers furnished almost entirely by the metropolis and its vicinage alone; and if but two thirds of this number were to go by the railway, that would produce, at sixpence each, a revenue of £50,000, which would cover an annual expenditure of £20,000, (the Liverpool and Manchester Railway, which is seven times longer than this would be, costs about £70,000 per annum) and yield a dividend of 7 per cent. on £400,000, which is the total estimated expense of the undertaking. The railway, as our readers have been apprised, is to commence at the Southwark end of the New London Bridge, and to be carried on the same level, upon arches, the whole way to Greenwich. By this means, no interruption will be given by the railway trains, to the ordinary traffic on the roads crossing the line. The height of the arches will just be sufficient to permit coaches or waggons to pass under, and as there are but two or three cross-streets where the traffic is considerable, the arches will, in general, be of the same dimensions. The number of 403 arches will probably extend to 900; and from their size and dryness, they will become useful as warehouses, shops, stables, coach houses, barns, &c. and thus yield a great addition to the revenues of the Railway Company. The time occupied in the transit will not exceed ten minutes, the distance being under four miles. To commercial and professional gentlemen connected with London and Greenwich, this celerity of conveyance will be of the greatest importance; as by this means a saving will be effected of upwards of 45 minutes each trip, or one hour and a half per day, being equivalent to nine hours per week by every individual, whose business requires him to perform the journey daily. On our front page, we have given a view of a portion of the intended railway, from which the mode of its construction, and the elegant appearance it is likely to exhibit, will be at once apparent. THE ARCANA OF SCIENCE FOR 1832.* The Arcana of Science has now been published five successive years, and may, therefore, be considered entitled to take its place among the established periodicals. Its projector and editor, we believe, is Mr. John Timbs, the editor of that popular and deserving weekly miscellany, The Mirror; and also favourably known to the public by his multum in parvo compilations under the titles of Laconics, or the Best Words of the Best Authors. The title of the book before us is, perhaps, the very worst feature about it; for a book which consists entirely of reprints of articles already published in the scientific journals of the day, can hardly be expected to bring to light many of the hidden things of science. Annals would be far preferable to Arcana, especially if the work, instead of consisting wholly of unconnected extracts from the mass of periodicals, were composed with more unity of design, and gave a connected view of the Progress of Science and the Arts for the year, an improvement much to be desired. The second title is also a Arcana of Science and Art; or an Annual Re. gister of Useful Inventions and Improvements, abridged from the Transactions of Public Societies, and from the Scientific Journals, British and Foreign, of the past year. London: John Limbird, 1832, pp. 310. 2 D 2 |