first parcel at a lower rate, and much less with the proposed per centage profit on the cost price (60d) added to it; this, therefore, is the true cause of the limit required to be accounted for. But if from the d. we take any per centage short of 20 per cent., there will remain a certain surplus profit, which we may consider as so much per egg towards making up the above-mentioned deficiency; and this being calculated by taking the proposed per centage upon the 60d. and adding it to the 12d., actual loss, nothing remains to be done but to divide this amount by the surplus profit per egg, and we obtain the answer required; for as this surplus profit is to the whole deficiency, so is one egg to the number of eggs necessary to supply it. For example, if 10, 15, 19, or r per cent. be pro posed, we have remaining from the d. or 20 per cent., severally 10, 5, 1, and 20-r per cent. surplus, ord. ¿d. d. and 20d. On the other hand, we 60d x 10 60d × 15 60d × 19 and 100 " 100 have 300 100 " BELL-RINGING PLAN ΤΟ ENABLE Sir,-For these several years past I have frequently thought of soliciting your attention to a fact connected with bell-ringing, that to me appears a complete infatuation. The mode of ringing a chime of bells in the belfries is to make each bell swing on a wheel and pivot, so as to acquire an inversed position in which the clapper strikes against it. This operation requires the utmost exertions of a set of strong men, so that it is looked upon as a feat of great prowess for eight men to ring a certain number of peals-"triple bob-majors," or other "bobs,” even minors, I suppose. The effects upon the belfries, through the violent swinging and motion of so many huge bells of many hundred weight each, is so destructive, that I could point out a dozen churches, besides that of Bow, in Cheapside, which have been threatened with ruin from the ringing of the bells. What is all this fuss and turmoil, and pulling and hauling, and puffing and sweating, endured for? To take the bell to the clapper, instead of the clapper to the bell! A bell of some tons' weight is swung round through an entire circle to produce one stroke of a clapper weighing one pound! I have heard of unexperienced ringers being caught up by the bell-rope to a great height, and then dropped on to the pavement with broken skulls and limbs. But that's nothing! They like it and put their foot into a noose of the rope, by which, I hear, they are often hoisted to the ceiling. This is their affair; but is it not the business of those who pay for churches and for bellringing to think whether it would not be more rational, easy, and beneficial to the steeple to invite the clappers to the bells, which might then keep their huge and ponderous bodies quiet! A line attached either to the internal clapper, or to an external hammer, might be pulled by a line with the power of a child of five years old. Any village blacksmith would have enough ingenuity to apply a spring which would remove the hammer or clapper from the bell the instant after the stroke; and if desired, dampers might be added, to stop the sound, as in a pianoforte. It would be much easier to keep time by this method, as the stroke would be simultaneous with the pull of the cord; whereas, at present the bell has to make a circular swing before the hammer touches it. In fine, a peal of bells might almost be rung by an arrangement of keys in the church, like those of an organ, and played upon by one man, if not with his fingers, at any rate, with his feet. Some time ago, a clergyman, who has the direction of a public school, complained to me of having to pay a man several pounds a year for tolling his chapel-bell on a Sunday; and asked me if I could not so manage it as to have it done by one of his little girls. Of course I did só-and that by pulling the clapper to the bell, instead of swinging the bell round to the clapper. The frost puts me in mind of skating, and of a plan I adopted, so long ago as 1817, to teach ladies to skate without the possibility of falling. I constructed a wicker go-cart, something in the shape of a bell. The upper rim padded, and drawn up under the arms by shoulder-straps. When put on, the bottom is only three or four inches above the ice, so that the wearer cannot fall even if she desired it. Many ladies would be glad to learn skating, but for the fear of falls. Here is their remedy, if you choose to give it them. Your obedient servant, Jan: 1, 1837. F. MACERONI. GAS STOVES. Sir,-As I believe gas is now brought more generally into use for the purpose of warmth, I wish, through the medium of your Magazine, to obtain some information as to the best means of applying it, and the most economical method of burning it so as to obtain the greatest quantity of heat. There are two ways at present in use, by one of which the top of the stove is open to the apartment, and, consequently, the whole of the heated and burnt air come immediately into the room; and perhaps in open shops, and in places where the gas is well made, there is not much objection to this; but for offices and private dwellings the other plan is far preferable, for thereby the burnt air is carried away by a pipe, and only heated air is produced for respiration. However, by the latter method, a portion of the heat is lost, being carried through the pipe out of the room. My object in writing is to inquire what is the best stove now in use for warming a room upon the hot-air, or close principle, and at the least expense, and I shall be glad if any of your correspondents who may have such stoves will favour us with the particulars of their construction, and the number of feet of gas per hour consumed, upon an average. I have one with a ring of 40 holes, and when burnt at a moderate height it will consume from 12 to 15 feet per hour; and I am afraid that a good heat cannot be obtained for much less: but at this rate it would be too expensive for general use, as if we reckon only 14 hours a day, it would consume more than 1000 feet per week, at a cost of above 10s. 6d.in some places more. I have seen Mr. Rickett's stoves, and believe their consumption would exceed what I have stated. I shall be happy, however, to learn the result of the surest of all tests-actual experience. It appears to me that the adaptation of gas for the purpose of warmth is capable of great improvement; and as it is a subject of growing importance, I hope those who can, will favour me and your readers with working accounts of any plan they may be adopting, and cost of construction, &c. P. S.-There is a curious fact connected with this subject which I should like to have explained by some of your scientific readers; whenever gas is burnt in a close apartment, the windows will become covered with damp. QueryWhat is the cause, and can the air be healthy to breathe? Again-If the burnt air from the gas in a hot-air stove be conveyed through an iron pipe, a quantity of steam will be continually formed, as from the spout of a tea-kettle -query, the cause? And is it by reason of the pipe being of iron? If so, what other material would do better for the purpose. NOTES AND NOTICES. Weather-wisdom put to the Proof. Our old friend Francis Moore has for nothing been more bitterly censured than his presuming to predict the weather. Yet, strange to relate, his trade has been taken up by the member of a scientific body, -the Meteorological Society, of which Dr. Birkbeck is president. In the course of December, they were presented with a prediction, founded on observations as to the prevailing winds, &c. of the weather to be expected in the present month, by a Mr. Murphy, as follows:-" The tendency of the weather throughout this month will be to drought. Frost may be expected to set in about the 5th of the month, if not sooner, and the period of greatest cold may be expected to occur on the night of the 13th, or following morning; succeeded by a thaw. Squally weather with rain thence to the 22d; after which, a return to frost, and dry harsh weather to the close of the month." Hitherto, at any rate, this prophesy has been by no means borne out by the event. The new year came in with frost, and the ground covered with snow; a thaw commenced on the night of the 2d, and by the 5th, when Mr. Murphy led us to look for frost, the thermometer looked up, and the thaw was proceeding with aug mented rapidity! As to the remainder of the month, nous verrons," as the French say; but, what with rain and melted snow, as yet it has had but little tendency to "drought." Mr. Murphy had better have let old Francis alone in his glory! The Keraphonite.-Amongst the presents on the table at the last meeting of the Royal Society, was an ingenious silver acoustic instrument, invented by Mr. Curtis, the King's Aurist, called the Keraphonite; it is fixed on the head for the purpose of collecting sound, which it does better than any contrivance hitherto employed. The one presented to the Society was made by Savigny, and is remarkable for its beauty of workmanship. The instru ment, if such we may call it, consists of a spring, which goes across the head, terminating at either end in a small horn (hence, probably the name), which rests on the ear,-Literary Gazette. Rickets's Gas Stove. This invention is for warming apartments where there is no chimney, and places where stoves have been used, but where the unsightly appearance and unpleasant effluvia arising from the piping are objectionable. The following is extracted from a pamphlet lately published, and which describes various new uses to which gas is applicable:"The writer has taken particular notice of a gass-tove, fixed last autumn, by Mr. Rickets, in St. Michael's Chapel, Burleigh-street, Strand, which only cost the sum of 147., and an swers remarkably well; consuming but from fifteen to twenty feet of gas per hour, whilst the attention is simply confined to lighting the gas over night, when the chapel is rendered of a comfortable temperature for morning service, a thing very uncoinimon, and only practicable by this mode; as every church, whether heated by steam, or hot water, or warm air, is dependent on almost an hourly atiention to a fire in some part of the building. The Rev. Septimus F. Ramsey, the minister of the chapel, in answer to a letter of inquiry, states, "It affords me great pleasure to be able to say that the gas stove, which has been erected in my chapel, has exceeded my most sanguine expectations, in asmuch as it gives a greater heat than my old warm air-stove, which cost the sum of 1217." Fire-Engines and Fire-Companies-Postscript by P. R.-I observed in my last that the question stood as originally put, viz., Why is Mr. Braithwaite's steam fire-engine not used for the purpose of ex tinguishing fires, or arresting their progress? Mr. Baddeley in answer to Fire-Fary." (No. 698), says, referring to the machine," All do not admit (some even deny it) of its being an effective instrument ("for both purposes"), and, THEREFORE, it has not been adopted. This is meeting the ques tion. Let Mr. B. first settle that to which he has given the preference, viz. as to whether the firecompanies are or are not irresponsible bodies, and we shall meet him on the second, and I will only observe, that if the fire-companies place no reliance on the efficiency of the steam fire-engine, which Mr. Baddeley declares to be the fact, and which Mr. Braithwaite as distinctly denies (see his several letters), sufficient evidence may be adduced to prove that Mr. Baddeley's premises are incorrect, and that the conduct of his undeserving friends is no less unjustifiable in this particular case than in their conduct towards Mr. Baddeley himself. This disposition to take advantage of the labours of others, and withhold, not only remuneration, but common courtesy, will not avail the Companies in every instance, and I entreat Mr. Baddeley not to overlook it henceforth as he appears to have done, and the more particularly in his promised detailed account of the comparative merits and capabilities of steam and manual power as applied to fireengines, which will doubtless include the new marine-engine, to be worked by three gangs of thirty men each! If this is to be worked on the voluntary system, Mr. Braithwaite will be blown out of the water; but the ninety-man power item 'must not be overlooked. Dec. 28. [In my letter of the 9th current," For" is substituted for " Nor" *in the third paragraph, which renders the context senseless.] Collier's Patent Boiler.-Sir, Mr. Collier has stated in the public papers that his boilers effect a saving of half the fuel; and he has, in your 699th Number, not hesitated to call in question the character of the gentlemen at Woolwich who reported to the Admiralty the performance of them in the Meteor. Will Mr. Collier now admit or deny, in your Journal, unequivocally, the veracity of the Report to the Admiralty, which states the consumption of fuel in that vessel during her experi mental trips in the River, &c, to have been fully as much as with the ordinary boilers. Or if he does not rely upon the performance of the Meteor, as to the saving of fuel, will he be good enough to say where or in what vessel such fact has been ascertained. It is a great pity, Sir, that the noble cause of scientific improvement is, too often without scrutiny, allowed to be damaged, almost past repair, by the wretched fashion (to give it no worse a name) resorted to by many inventors of putting forth statements not warranted by experiment. Or course, I do not class Mr. Collier with such, unless his reply to the above shall be found to fail him.1 am, Sir, &c., T- H-. Improvement in Fire-Tonys.-Sir. In Number 602 of your useful and entertaining Magazine, I informed you of an invention of mine for preventing lumps of coal slipping from the chaps of the tongs in carrying thein from the coal-scuttle to ..the fire. I now find, that by boring holes through the chaps of the tongs, opposite each spike, and countersinking them on the inside, is an improvement on the original invention, as it permits the chaps to come closer together, and the points of the spikes are defended from injury, being sheathed in the holes. I am, &c., J. BULLEN.-Bath, Jan. 2, 1937. The Supplement to Vol. XXV., containing Title, Table of Contents, Index, and Plate of Specimens of English Medallic Engraving by Mr. Bate, was published on the 1st of December, price 6d. British and Foreign Patents taken out with economy and despatch; Specifications, Dis. claimers, and Amendments, prepared or revised; Caveats entered; and generally every Branch of Patent Business promptly transacted. A complete list of Patents from the earliest period (15 Car. II. 1675,) to the present time may be examined. Fee 2s. 6d.; Clients, gratis. Patent Agency Office, Peterborough-court, Fleet-street. LONDON: Published by J. CUNNINGHAM, at the Mechanics' Magazine Office, No. 6, Peterborough-court, between 135 and 136, Fleet-street, Agent for the American Edition, Mr. O. RICH, 12, Red Lion-square. Sold by G. W. M. REYNOLDS, Proprietor of the French, English, and American Library, 55, Rue Neave, Saint Augustin, Paris. CUNNINGHAM and SALMON, Printers, CURTIS'S TIMBER-FRAME RAILWAY. Sir, I beg to forward a plan of my timber-frame railroad, which I carried into effect three years ago in Mexico. A small length has been laid down in the workshops of the London and Greenwich Railroad Company, and which has been in use for about eight months without the smallest deterioration up to the present moment. I have made a public exhibition of it during all this time, and recommended it to various Railroad Companies; and to the Southampton Railroad Company I presented a model in January, last year. This model, I have no doubt, is now in the possession of the Company. I make these observations in consequence of your publishing, in your last week's Magazine, the plan of a railroad on the same principle by Mr. Vignoles. That two parties, perfect strangers to each other, should propose similar methods for effecting the same object, is perfectly intelligible; but, as amongst imaginative men, there is great tenderness felt upon the point of priority of their inventions, I send the enclosed, with its explanation, that you may lay the same before the public. Your readers will not fail to note in what respect we agree in principle, and how differ in detail. I am perfectly convinced that no method is so good as the frame-rail in all cases, and more especially in madeground embankments. I have found in Mexico, a climate as hot as Jamaica, that although I have put the timber in green, the made-up jointing is so excellent, that the tendency which all timber has to twist only makes the joints stiffer. Putting in the timbers in 10-feet lengths requires no cross-tie, but a longer length does so. The rail, as I have drawn it, is formed of 9-inch planks placed on edge; the sleepers and cross-ties are made also from planks. Fig. 1, is a side view, in which a a are the longitudinal rails, b the sleepers, c the cross-ties; and the same letters refer to the same parts in all the figures. The mode of jointing is shown in fig. 2. It is thus apparent in what way I secure the two rails and sleeper at one operation, the under tennon of a' entering half way into the mortice of the sleeper b, the rail a is then passed into the scarp at a', and its under tennon midway into the same mortice of b, when the sleeper is thus held firmly between both rails, and two treenails passed through the joint makes all secure. The upper surface of the timbers is then shod with an iron bar, which is secured by wood screws countersunk. A har of iron, a quarter of an inch thick, and 2 inches wide, weighing 6lbs. per yard, is quite sufficient. I have found that this class of rail, with only hoop-iron of one-eighth of an inch thick, suffers scarcely any perceptible deflection by our heaviest carriages passing over it; and this consequence, arises from the iron being held securely between its soffits, and the effect of the load being not to crush it, but to tear it asunderand it is a well-known fact, that a bar of a square inch section will carry a load in the direction of its length, nearly fifty times as great as when bearing (as is the case in the common rail) the load, the two ends of the rail being unconfined. The cost of a lineal yard for a double track will cost about 25s., or 2,2001. per mile. This is a very different state of figures from that shown by Mr. Vignoles; and his arguments being indefeasible, I hope he will excuse me making them a matter of reference. Fig. 3 is a plan of the frame. In the case of a double rail the sleepers b must be continued across, so as to take both lines; c shows the tie-piece with its keys. Fig. 4 is the same thing applied upon an embankment; the sleepers b are prolonged, and the upright part ff are notched into it; along the top of these parts a rail g is spiked, thus making a very powerful parapet, and at a much cheaper rate than any other possible method, the whole combination having a tendency to hold up the rail. The struts h will furnish such security to the parts as I am certain no engine in ordinary circumstances could ever break through. N is the soil. Your publishing the above in your earliest Number will much oblige Sir, Your obedient servant, Deptford High-street, Jan, 10, 1837. |