192 NOTES AND NOTICES. NOTES AND NOTICES. Velocity of Water-Wheels in the Night.-Popular notions must always be a subject of curiosity and interest to philosophical inquirers, whether these notions are founded on observation, or confounded with superstition; and we are not aware that any popular notion is urorextensively diffused among inflers (though many of them may not be lieve in it, than that which ascribes a greater velocity in the night than in the day to a waterwheel under the same head. Why there shoul be any difference, none of the believers in this doctrine have even been able satisfactorily to explain. To argue against it has been futile, because early prejudice was stronger than the powers of reason; and, therefore, no other way remained that could prove effectual, bu to bring it to the test of experi ment. For this labour we are indebted to Professor Claveland. His statene t, which follows, is co tained in a letter to Professor Silliman, and published in the American Journal of Science and the Arts:" In a former letter I mentioned the opinion existing in this part of the country, that saw-mills move faster during the night than the day. The explanation usually given by the workmen is, that the air becomes havier after sunset. I selected a fine day in August, and requested that all the mill-gates might remain stationary for twelve hours, At two o'clock p. m. 1 suspended a barometer in the mill; the pressure of the atmosphere was equal to 30 19 inches; the temperature of the water just before it passed the mill-gate was 72° Fahr. The log.was then detached from the saw, and the number of revolutions of the wheel, being repeatedly counted by differen persons, was 96 in a minute. At midnight I again visited the same mill. The barometer stood at 30 26 inches, the pressure of the atmosphere hav ing increased 'seven hundredths of an inch. The temperature of the wa er was 729, the same as at the preceding observation, although it had been a little higher during the afternoon. The log being de ached as before, the wheel was found to revolve precisely 96 times in a minute, showing the same velocity as at the preceding noon. The depth of the water was the same during both experiments. The workmen were satisfied that the result of the experiment was correct, but still they seemed to believe that it would be different in a cloudy night."-American Railroad Journal. To Purify Cold Short Iron, a very simple process is practised in some bloomeries, which consists in throwing on the loupe at the moment when it is formed, half a shovel full of powdered flux, and keeping it afterwards exposed to the air of the bellows for a few moments, before it is carried to the hammer. The flux thus employed is a limestone, which yields lie of good quality. Its effects on the loupe are very prompt, depriving the iron of the silerite or phosphate of iron, which, as is well known, renders the iron brittle when cold. -lb. Method of Bronzing Iron and Gun-Barrels.-Gun-barrels when damasked are ess liable to rust, and any of them, of whatever price, may be treated by a very simple ethod, which will diminish their readiness to oxydise. When the iron is well scraped and cleaned, cover its surace with a coating of butter of a timony. If one is not sufficient, two or three coatings may be given. The iron thus acquires a horny reddish brown colour, which is not unhandsome, and which preserves it from rust. When the iron has acquired tre desired tint, wipe it carefully, warm it a little and then rub it with white wax, until there remains no longer any visibie traces of the wax. This renders its preservation complete.-Ib. A good Safe, or victual-preserver, is prepared by making it of a double esse of wire-gauze, and filt ing the interval with fresh charcoal, in fine pieces. Fresh meat, when suspended by hooks from the top, will keep good and sweet for a week in this safe, in the hottest weather.-Ib. Method of Coating Busts and Plaster Casts, so as to give them the Appearance of Marble; by M. Pleuvarre.-into a wooden tub or trough, put a strong and warm solution of alum. Into this plunge the bust or plaster cast, previously mae perfectly dry, and let it remain therein from fifteen to thirty minutes; then suspend it over the solu tion, that the superfluous portions may drain off, and when it cold, pour over it a fresh portion of the solution, and apply it evenly by a sponge or cloth. Continue this opera ion until the alum has formed a crystallised coating over the whole surface. Put it aside, and when perfectly dry, polish it with fine sand-paper, or glass paper, and complete the polish with a cloth slightly moistened with pure water. A wooden vessel is best for the solution, warmed by steam from a boiler, because metals are apt to colour the solution. This coating gives greater solidity to the substance, and possesses the whit-ness and transparency of the finest marble. It stands the attacks of moisture in any apartment -is less subject to become soi ed, and is as easily cleaned as farb e: In this manner, excellent copies may be obtained of antiques, as well as moderas, at a price little exceeding common plaster Casts.-American Journal of Science and Arts. New Iron Steam Boat. -The wrought-iron steam. boat, ordered from England by the Steam-Boat Company of Georgia, arrived (in pieces) at Savannab, last week, on board the British ship Aleyons Captain Muir, from Liverpool. Her length is 120 feet, her beam 26 feet, and her depth 7 feet. It is estimated by her builders that she will draw, with all her machinery and every thing on board, 2 feet 3 inches. She will have an engine of 46 English horse-power, on the low-pressure prmciple. American Railroad Journal, April 23. Communications received from X. Z.-A Subscriber Mr. Henderson-Mr. Pearson-Mr. Curtis -Mr. Smerdon-Mr. Baddeley-F. H.-Colonel Maceroni-Mr. Croft. Errata.-In No. 670, p. 133, col. 2, line 23 from bottom, for "common river" read " common sewer."-P. 134, col. 1, line 32 from top, for “ the church" read "the whole." The Supplement to Vol. XXIV., containing Ti tle, Contents, Index, &c., and embellished with a Portrait of Mr. Walter Hancock, C. E., is now published, price 6d. Also the Volume complete in boards, rice 9s. 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. LONDON: Published by J. CUNNINGHAM, at the Mechanics' Magazine Office, No. 6, Peterbo rough-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, Proprie or of the French, English, and American Library, 55, Rue Neuve, Saint Angustin, Paris. CUNNINGHAM and SALMON, Printers, 191 PLAN FOR A NEW PUMP FOR FEEDING STEAM-ENGINE. BOILERS. During the operation of feeding, the plug, A, B, is caused to revolve around in its seat; this may be done by placing a pulley upon its axis, as shown at P, fig. 2, and strapping it from any convenient part of the engine. In order to show the operation of this machine more clearly, I have supposed a water tank, K, L, to be placed directly upon the upper flanch, with a pipe and ball cock from the water pipes in the streets, to supply it with cold water. The ope ration of this pump will be as follows: When the engine is put in motion, and, COLsequently, the plug, A, B, the opening, w, in the plug, will be brought round to the position shown in fig. 1; in this position, the cold water from the tank above will descend the hollow or cavity in the plug; bit as the pug revolves, when the opening, w, has passed the opening in the upper flanch, the connexion with the tank will be cut off; and when the opening, w, moves round, and comes over the opening in the lower flanch, the water from the plug will descend, and pass down the tube into the boiler, C, D. It will be obvious to the mechanician, that the quantity of water passed into the plug in one revolution, may be regulated in several ways, either by enlarging the opening into the plug, or by giving the plug a quicker, or slower, motion, at the time the openings are in juxtaposi – tion. To equalize the pressure above and below the water in the hollow of A, B, a small pipe, or channel, x, y, is made to the casing, H, I, whereby the steam passes up to the opening, y, in the casing; and when the opening, w, of the -plug, is over the lower opening to the boiler, the small hole, z, will be in con-, nexion with the opening, y, so that the stream is then admitted into the top of the hollow of the plug, and the water in the plug will descend freely by the force of gravity. A similar opening may be contrived for the free admission of the water from the tank into the plug. Having now described this pump, I shall make a few remarks in reference to what I conceive to be its advantages. And first we have an apparatus which will perform all the functions of a forcing pump, without valves. Secondly, The only resistance in the working of this pump, will arise from the friction of the exterior surface of the plug against the casing, as it revolves. And, thirdly, It is a sure and certain regulator for the supply of water to the boiler. The first two items above mentioned are so obvious, that it were needless, perhaps, to comment upon them; the latter item, however, may not be quite so apparent. I will there. REASONS AGAINST INTERFERENCE WITH THE BAILWAY SYSTEM, fore show how the pump may serve If we 195 will be within the tank, and the hole, q, within the chamber, C, D; hence, water from the tank may flow in and fill the chamber, C, D; and when the plunger is down, as is represented in the figure, the hole, q, will be open to the boiler, and the water in the chamber will dedescend, through p and q, into it. The relative diameters of the plunger, and that of the chamber, C, D, may be varied to suit the motion which is given to the plunger. Philadelphia, February, 1836. Thus, P. S.-I am aware that, in the practical operation of the above described pumps, some difficulties will probably occur, but I ain fully pursuaded that they are not insurmountable. for instance, when the pump is designed boiler, as it would be necessary to have to regulate the quantity of water to the the connexion of the feed-pipe with the boiler near the top water line, the water from the boiler would frequently rise in the tube, and run up to the pump before the body of water in the boiler la risen to cover the opening of the feed-pipe. This difficulty would be remedied by a small tube from the top of the boiler, fig. 1, to the opening, y, in the casing of the pump, REASONS AGAINST THE DUKE OF WEL- [We extract the following very judicious observations on this head, from a appeared, in the Courier of Tuesday, letter to the Duke of Wellington, which June 7th.] It is the peculiar characteristic of this country that great public works can be exe cuted by private capital and enterprise without assistance from the public purse; and to the encouragement which this spirit has received under a free and constitutional Government, may be attributed the vast benefits which the nation has derived from its canals, its docks, and other public improvements. Wealthy individuals have been found ready to advance their capital for such works, because they could rely on the good faith of the Government and the country at large in securing the possession of their property. It is, therefore, the duty of Parliament to take care that in their endeavours to protect the people from the consequence of a possible monopoly in these works, they do not run into the contrary extreme, and, by ill advised 196 REASONS AGAINST INTERFERENCE WITH THE RAILWAY SYSTEM. restrictions, put a stop to them entirely. It is my opinion, that, in a national point of view, this latter consequence is far more to be, apprehended than any other danger of monopoly. A capitalist embarking money in these works is well aware that he incurs a certain risk. It is only from the hope of a possible large profit that he will engage in them. If you cut off this hope you extinguish the spirit of private enterprise, and with it the means of national advancement. But it is said that the public have a right to some participation in the profits of these, works, and that when an ample remuneration has been obtained by the proprietors, the people at large should then be admitted. I entirely agree in this constructive right of partnership, provided it be arranged likes other partnerships on equitable principles, But the public must, on the common principles of justice, take a partnership in the whole, they cannot claim to share the benefits of those undertakings which may prove to be prosperous, without first deducting the loss arising from others which may have failed. I will give your Grace an iiistance to show how this principle would work. Two of my friends and myself were origi. nal shareholders in the Southwark and Waterloo Bridges. You will adnit that both these works are of great general atility, the públic derive daily and permanent begefit from them, but we are losers of upwards of 12,000l. We now hold shares in railways from whence there is every prospect of gradually retrieving that which we have lost on the bridges. If we do so retrieve our capital, the public will still be the gainers by the subsistence of the works, but I totally deny their claim to be admitted as our partners until we have so retrieved it. This case your Grace will find on inquiry, to be by no means a singular one. There are hundreds in the same position; and it is a fact capable of the strictest proof, that if the sum total of capital expended by private individuals in works of admitted public utility is taken in the aggregate, and the sum total of the income derived from those works is get against it, it will be found that they do not on an average return an interest of three per cent. So long as this state of the account remains, the public can have no right to complain, nor can they claim to be admitted until the balance is shown to be largely in favour of the proprietors. But I would wish the subject to be considered in another and still more important view. It is apparent, from the extent to which these works are projected, that there is a large unemployed capital in the country. This capital is chiefly in the hands of persons who have earned it in commerce, and is a test of the general prosperity of the country, But the persons so possessed will dispose of it to. the utmost advantage, and if the means of doing so are not given in our own country, they will seek them in others. ; This is no matter of speculative opinion, it is an actual fact; and there are foreigners, at this moment in London attempting to raise English capital for the execution of works of: this description on the Continent. They cannot effect this to any extent, so long as there are channels open at home; but once impo e restrictions, such as to shake publies confidence here, and you will see the conseg quences. English capital, to an enormousz amount, will be sent abroad, where they are anxious to obtain it, and will not impose restrictions, Gold must necessarily be exported, and a panic like that of 1825 will ensue. I am no alarmist, nor do I wish to overstate these consequences, but I firmly believe the apprehension to be well founded, and as all experience has shown it to be, so I should act on is myself. I think these facts will tend to convince your Grace, that the measure you have pro posed is not one affecting merely a few spe-r culative individuals, but that, it is really a great and important public question, and that if entered on by Parliament, it should be considered as such, and be discussed gravely and with sufficient notice. It is not a matter which ought or can be properly considered on the debate of one or two particular measures, and I insist the more earnestly on this, because I must say that, with every respect for your Grace, the proposition was made in a manner and at a time which showed that you did not appreciate its extent or importance. par It appears that the House of Lords did, i early in the session, consider and determine on the course they should pursue with referenee to the railway bills, and certain reso lutions were promulgated, on which the ties have hitherto proceeded. It seems, moreover, that several of such bills have actually passed, and have received the royal assent according to the established practice, and but for the (perhaps accidental) circumstance of your Grace's presence on Friday last, that bill on which the question arose would have passed also. Now I do say that this species of haphazard legislation is not that which the subject deserves, or which the country is entitled to expect. There is scarcely a family of respectability in the country which has not some member of it more or less interested in these works, and if a great change is to be made, the people are entitled to expect that it should be made deliberately and after full こ |