Sidebilder
PDF
ePub
[blocks in formation]

linders, A and B, and communicate with them by the valves P and Q. Suppose, also, the pipes C and D (each 36 feet long) connected to A and B, and communicating by the valves R and S; H and K are pistons, having the valves M and N in them, working perfectly airtight in A and B, aud giving motion to the beam, ECF (about the centre, G), and such machinery as may be connected to it.

To set this engine to work, fill the pipes, C and D, with water, and put down the valves R and S, and a column of water, nearly 34 feet high, will be retained in each of them. Next open the valve P, and the water rushing out of the cistern, L, into the cylinder, A, expels the air in it through the valve M, and fills it. Now, shut P, and open the valve R, and the water in A will descend through the pipe C, and leave a vacuum under the piston H, which piston will descend by the atmospheric pressure, and raise the piston R.

The descent of the piston, K, is effected in a similar manner, and thus a reciprocating motion is given to the beam, EGF, similar to that in the improved engine of Boulton and Watt.

Suppose Tabcde RSV a line drawn to touch the bottom of the cylinders; WX, a river, or, it may be, a pond or cistern, whose surface is 37 feet below TV. Let us imagine a steam engine erected at a, of four-horse power, for the purpose of pumping water up from this river or pond, to supply an air and water engine at b. I will suppose it capable of pumping sufficient for an eight-horse power at b, and it is obvious that, by employing a fourhorse power cut of eight-horse power air and water engines, erected at bede, &c. in pumping we shall have an effective power of four horses at the points bede, &c. for any other purpose. If a greater power were wanted at any point, say e, use the engines at abe and d, entirely for pumping, and (per our supposition) we shall have a power equal to 64 horses at e. So far with conjectures. There are many in

[ocr errors]

among

genious mathematicians? your readers and correspondents; I should be obliged if some one of them would answer the following questions

1

Admitting the pressure of the atmosphere to be equal to that of the steam used in Boulton and Watt's engines, it is required to find what power (horses) will pump the quantity of water, 9 (42 feet high), necessary to keep an air and water engine similar to the above constantly at work, when the diame ters of the cylinders, A and B, are each a (24 inches), the length of the stroke b (60 inches), and number of strokes of the piston of each cylinder, c (22), from top to bot tom (or the distance each piston passes over be 220 feet per minute).

It is also required to find the diameters (d and e) of the circular holes covered by the valves RSPQ, necessary to fill and evacuate the cylinders, supposing the cistern, L, always to be filled with water to a level with the bottom of each piston, when at its highest point in the cylinder.

If some of your readers among the operative mechanics would point out a mode by which the valves might be made self-acting, as also the mode of governing the engine, they would confer additional obligations.

[ocr errors]

I am, Sir,
Yours respectfully,

A MEMBER OF THE BOLTON
MECHANICS' INSTITUTE.

Bolton, 3d July, 1825.

STANDARD MEASURE.

Caroline has seen Emilla's proposition for a Standard Measure,' in No. 103 of the Mechanics' Magazine, and requests the favour of you, Mr. Editor, to tell her, that, admitting the sun would mark the same length of line in one hour, without any variation throughout the there year, would still require a conventional agreement on the distance of the aperture, through which his light is proposed to pass, from the surface

ANSWER TO INQUIRY

on which he would mark his line; it would, therefore, be an artificial standard, and not a natural one, as appears to be the desideratum, and a similarly founded proposal has been. argued down in your former Numbers. The plan of 'C. H.' although conventional, seems nearer to nature than Emilla's. It was this To take six feet for the medium height of a man, by which the fathom would be found; half his height, the yard; the length of his foot, being properly one-sixth part of his height, would be our present foot measure. August 13th, 1825.

[blocks in formation]

be Windsor, mottled, or yellow?! and also whether the soap, wax, and water, are to be boiled together, or only left to dissolve in hot water? It is also important to know: the proportions in which they are to be nixed? It is true Dr. Johns states he had not ascertained them exactly, but still he might communicate the proportions which he has found to answer his own purpose, which will, no doubt, answer mine as well. How the varnish is to be applied is another important point in this question. I remain, Sir, Your obedient servant, AURUM.

ANSWER TO INQUIRY.

NO. 134.

-VARNISHING STUCCO
IMAGES.

SIR, In answer to Aurum's inquiry in the 98th Number of your Magazine, concerning the varnishing of Stucco Images, I send you the following easy method:

Rub the image over with a piece of white wax, after which it may be varnished with any white varnish; for instance, shellac dissolved in spirits of wine.

ANOTHER METHOD.

After the image has been well cleaned, it is to be brushed all over with whiting and water, and, when quite dry, brushed over with fine parchment glue.

I am, Sir,
Yours respectfully,

W.TATNER.

FURTHER EXPLANATION DESIRED.

SIR,I shall be obliged to Dr. Johns if he will inform me on the following points as to the composition of a varnish for stucco images. He has merely stated what the ingredients are, without giving any information as to the proportion which each must bear to the other in the mixing of them, &c. &c. I wish to know whether the soap is to

NOTICES

ΤΟ

CORRESPONDENTS.

The Anecdote communicated by “ Au- rum," respecting the trick of the Glasgow Publishers, exposed in our last, is very piquant; but we had rather drop the subject. "A writer in the Glasgow Mechanics' Magazine" trusts, that we do not suppose "the Committee of Engineers, who edit that work, have any concern in taking the mean advantage" complained of. Not knowing who the members of that Committee are, we cannot judge what they are capable of doing; we only know, that every monthly part of the work they edit contains, among the recommendatory notices on its envelope, what they must, one and all, be perfectly aware, is a fraud upon us, and a gross imposition on public credulity.

A. V. wishes" a direction to the best place for procuring iron frames for melon beds."

"Turnscrew" expresses his "disappointment at not finding a farther communication in our recent Numbers from Mr. Monnom, on the subject of Screw cutting. He trusts that Mr. M. will oblige...... our readers with the fulfilment of his promise, and, at the same time, explain more clearly his contrivance for Screwcutting, described p. 166, vol. iv. He wishes us to ask Mr. M., if his plan is applicable to cutting screws in wood and

[blocks in formation]

ivory, as well as metal, and to female screws?"

Mechanicus "will make an appropriate acknowledgment to any person who will inform him, by letter, if it is possible to make a bottle luminous, either corked tight or uncorked, and, if possible, how long it will remain so?" The letters may be addressed to the care of our publishers.

A Correspondent at Bath would be obliged to any of our readers for "the Plan of an Economical Grinding Machine for Razors, convertible into a Turning Lathe."

A "Tipton Brewer," referring to Mr. R. W. Dickinson's reply to X. X. (p. 123, vol. IV.), where he politely invites X. X., or any other person, to come and inspect a considerable improvement in his cleansing apparatus, remarks, that " not having any business in London, and residing at a distance, he cannot avail himself of the invitation." He trusts, therefore, that, for the benefit of all who are situated as he is, Mr. Dickinson will, through the medium of our pages, describe that improvement. Our Correspondent has adopted the plan, and highly approves of it; but when he "cleanses earlier than the scientific brewer lays down his rule, he finds the cleansing cap of the dimensions given not sufficiently large to hold the yeast working out."

A Constant Reader asks, if " any of our Correspondents can put him into the way of boring a brass cylinder, about two inches and a half in diameter, perfectly true; and also to construct the most suitable Valve for an Air Pump? The common bladder-valve cannot be used in all cases, because it is not flush with the surface it is fixed upon."

A Correspondent at Barnard's Heath says, that if the person who signs J. to a communication respecting the Management of Bees (Number 98), will allow him the pleasure of a sight of his Hives, he will willingly go fifty miles for the purpose."

[ocr errors][merged small]

on Stenography." We do not know of any book on the former subject which treats of the art of reasoning in as practical a manner as we should like to see it taught; but, for the present, Watts' may be considered the best. The art of Stenography, according to the latest improvements, will be sooner acquired by Mr. Harding's little treatise than by any we have ever met with.

The account of the "Origin and Establishment of the Alnwick Scientific and Mechanical Institution" in our next.

T. H. B. had better apply to the first of the Societies he mentions.

P.L. M. desires to be informed" which is the best work on Fluxions, for a person to study, who has not the advantage of a teacher, and which work best shows the practical application of Fluxions?"

"Can the date of Old Silver be ascer tained by its official Stamp?"-A Constant Reader.

Communications received from--R. W.

-An
Inquirer--Mr. Dowden-Mr.
Lewthwaite-W. G.-R. Farley-E. S. T.
-Sir J. Senhouse-A Bleacher-Aurum
-Mr. Grimes-G. S. D.-M. P. M-The
Tanner-A Constant Reader-Z.-Dixon
Vallance-R. B. B.-W. Bell-W. Tat-
ner-Wm. Lake-Au Old Toper—A.—
W. J-D (Warrington)-A Man in the
Moors.

ERRATA.

P. 271, col. 1.-For Mr. J. H. Bell, read, Mr. T. H. Bell.

Advertisements for the Covers of our Monthly Parts must be sent in to our Publishers before the 20th day of each Month.

Communications (post paid) to be addressed to the Editor, at the Publishers', KNIGHT and LACEY, 55, Paternoster-row, London. Printed by MILLS, JOWETT, and MILLS (late BENSLEY,) Bolt-court, Fleet-street.

[ocr errors][ocr errors][ocr errors][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][graphic][subsumed][subsumed][ocr errors][ocr errors][ocr errors][ocr errors][merged small][ocr errors][ocr errors][merged small][ocr errors][ocr errors][merged small][ocr errors][ocr errors][merged small][ocr errors][ocr errors][ocr errors][merged small][ocr errors][ocr errors]

322

ALNWICK SCIENTIFIC INSTITUTION.

A MACHINE TO LOWER COFFINS.

SIR,-Having called the other day at a friend's house, he kindly put into my hands one of your useful Magazines. On perusing it I saw an inquiry (page 396, vol. 11.) for the invention of a Crane to lower a Coffin into the Grave, and, after some consideration, I thought of the following plan for that purpose.

Description of the Drawing.

Let a frame (fig. 1), about six feet four inches long, two feet four inches wide, and two feet high, be constructed of inch and a half yellow deal, so as to be portable.

[blocks in formation]

Suppose AB to be two rollers, three Literary and Scientific Instituinches diameter.

DD, the webbing.

EE, two friction-rollers, made to slide in a groove, fixed with a pin in the rail, to keep the webbing from the edge of the grave as the coffin is lowered down.

F, a wheel, one foot ten inches dia

meter.

G, a nut, eight inches diameter, on the end of the roller, A.

H, a nut, eight inches diameter, on the roller, B.

I, a nut, with a handle running in the great wheel, and turning the nut on the roller, B.

The three nuts must be of equal size, and equal in number of teeth, about an inch pitch.

On the roller, B, let there be three studs for each webbing, to take out the webbing when the coffin is lowered down; the webbing having three holes or loops at the end, to fasten it to the roller on the studs. A rotchet-wheel to be put on roller B, at the end next the nut.

Fig. 2 represents an end view of the machine. The mode of using it will

be as follows:

Place it over the grave; turn the handle of the nut, I, to tighten the webbing; then adjust the two frictionrollers to the edge of the grave by the pins in the rail. When the coffin is brought to the grave, let it be placed on the webbing, when a person has only to take hold of the handle and

tions," setting forth their advantages, and the facility with which one might be established in Alnwick, was distributed in the town and neighbourhood on Saturday, September 16, 1824. In the termination of the address Mr. Bell observed-" Should this suggestion be disregarded now, I trust it will ultimately resemble those germs whose vegetative power is uninjured by long inhumation, and which await but an exposure to a favourable atmosphere." Accordingly, the germination and fructífication were not far distant; for, on the evening of the 1st of December, a public meeting was held in the Town Hall, pursuant to resolutions adopted at a prevíous meeting of friends to the Institution, in the school-room of Mr. John Pears, A. M., to whose exertions, those of Mr. William Davison, chemist, and Mr. M. T. Johnson, the greatest praise is due.

This meeting was of the most flattering description, numerous and respectable; it exhibited the appearance of an election, and augured the most complete suc cess. The chair was taken by Mr. James Russell, senior, a mechanic of fifty years standing, whose sil ver locks and serenity of aspect added grace to the manner in which he opened the business of

« ForrigeFortsett »