1814316 - 54,9 horses' minute ; then 33000


THE “ AIR AND WATER engine.” &c. are shut. The cock is worked 1814316lbs. lifted one foot high in one by the wire, PP, fig. 1st and 2nd, joined to the thermometer frame at

one end, and to the handle of the power. ·cock at the other. It is set to any At what power he will estimate his required degree of heat by the sliding machine, when completed, I do not scale, which changes the centre of know; but here we see that it will regravity of the tubes.

quire no less a power than fifty-four A perfect specimen has been ex

horses to lift water necessary to work hibited at W. and D. Bailey's, 272,

this air and water engine. Holborn, since 1818; and the de

The next thing will be, to try if we tails of construction will be found

can find the power of this machine

after water is supplied to it, and in in the Patent Office, 1816, or the doing this we will allow him the full

I am, Sir,

the square inch), and say nothing Your obedient servant,

about the friction of his machine.

First, then, the area of the cylinder J. L. E.

=452,39 x 15 x 220=14928871hs. lifted one foot high in one minute, and



0 = 45,23 horses' power; from Sir, In looking over your 104th this it is evident that, instead of gainNumber of the Mechanics' Magazine, ing power, he will be minus nearly I observe a drawing and description of ten horses! The reason of this is a machine, which your Correspondent obvious, because he puinps his water (a Member of the Bolton Mechanics' 42 feet high into the cistern, L (which, Institute) calls a Water and Air Engine, by-the-bye, I cannot find in the drawfrom which (per his supposition) he ing), and he has only the advantage of can have power, almost ad infinitum, 34 feet fall, or, in other words, the at a very small expense compared with pressure of the atmosphere to gain the steam-engine ; but I am much power by. Even if this were not the afraid that his supposition will be case, and the water were only raised found altogether fallacious. Neverthe- to the same height as it had to fall, less, as he has asked the opinion of the rising and falling columns would 'others of your Correspoudents, I will only then balance each other, and he venture to give him mine. I shall, at would be minus the friction of the two present, pass over the first part of his engines, without still gaining one pound communication (where he says he shall of power. make an air and water engine into

I would here heg leave to remind eight lorses' power by the assistance of

your Correspondent, that water cannot a four-horse steam-engine, &c. &c.)

be made use of, as a power, to adand come direct to his question, which

vantage in any other way than by it's is put in so very tangible à shape as

gravity, and the best application of makes it quite easy to handle it. ' It is

this is upon the water-wheel. But iu substance this :- What number of

should he (contrary to my expectation) horses' power will be required to pump

succeed in convincing himself and me, Water 42 feet high, sufficient to supply

that one single pound of power will ever two cylinders, each 24 inches in dia

be gained by the air and water engine meter, and making 22 strokes of five

more than is required to supply it with feet each per minute ? Now, accord.

water, I then will engage, with great ing to this, a column of water 220 feet

pleasure, to send you a complete plan long and 24 inches diameter must be

of valves and working gear, with a supplied every minute, and listed to the

motle of governing the said engine, height of 42 feet, for the use of his water and air engines.

As I have no other end in view but This is no

of giving and receiving instruction, I joking matter, I can assure him; and

hope your Correspondent will not find as he wishes to know what power will be required to do it, I will endeavour

fault with my feeble atteinpt 10 unde

ceive him. to inform him.

I am, Sir, . , . oj. First, then, 242 x ,7854 = 452,39 2610

Yours respectfully, = 4235 alė gallons, and x 10,2=

A MAN IN THE MOORS. 43198lbs, to be lifted 42 feet high, or Angust 30th, 1925.

ANNUAL RETURNS OF MECHANICS' INSTITUTIONS. 411 HOW TO RESTORE THE COLOUR or after remaining at the bottom for WOOLLEN CLOTHS DISCHARGED abont thirteen minutes, it returned BY AN ACID.

apparently much exhausted, as it SIR.-Having accidentally spilled coiled itself closely under the little some strong solution of oxalic acid platform, and remained afterwards on a pair of black trowsers. the without inotion. Zuological Journal, colour was discharged, and the place,

vol. i. 283. which was large, turned of a yellow colour. The following day I dissolved some pearlash in water, with

NEW SCARLET COLOUR. the addition of an equal portion of Mr. Badams has recently described quick lime, and sponged the part a process for obtaining scarlet chrowith it. The alkali rendered the mate of lead, and highly recommends stain and the adjacent part, which its use as a colour either in painting was tvetted, of a dark foxy brown; or calico printing. He prepares the a little vinegar, now applied, restored scarlet chromate by boiling yellow all to its pristine black, and I defy chromate of lead with potash, and has the most experienced scrutinizing made several experiments upon the Hebrew to discover the place. properties of the scarlet colour thus I remain, Sir,

obtained. It appears that it may be Your obedient servant,

made what is termed a fast colour

in calico printing, and that it is a ALKALI.

durable and beautiful colour when used with oil, possessing consider

able body. It is not degraded in its SUBMARINE EXPLOITS OF THE

hue by admixture with white lead, HOUSE-SPIDER,

as vermillion is; and it also mixes

with other colours. As a waterA Honse-Spider was placed by Mr.

colour it has not been sufficiently Bell on a small platform, in the mid

tried to render it certain that it will dle of a rúmmer full of water, the plat- not blacken : but several slips of card form being about half an inch above

and thin paper, painted with it, and the surface. It presently made its

hung up in situations likely to affect escape, as was anticipated, by suffer

colour, have not, in some months, ing a thread to be wafted to the edge

perceptibly diminished in brightness. of the glass. Mr. Bell, suspecting Mr. Badams very justly remarks that, it might have been assisted by the should it succeed, no iint would be a water being so nearly on the same more desirable accession to the pallet level, poured some of the water than a bright and permanent scarlet, away, and placed the spider as be

or scarlet orange. fore. It descended by the stick that supported the platform, tillit reached the water, but finding no way to

ANNUAL RETURNS OF MECHANICS' escape, it returned to the platform, and for some time employed itself

INSTITUTIONS. : ; in preparing a web, with which it We earnestly solicit the attention loosely enveloped the abdomen, by of the Managers and Secretaries of means of the hinder legs. It now the different Mechanics Institutions descended, without hesitation, to and Mechanics' Book Clubs throughthe bottom of the water, when Mr. out the kingdom, to the excellent B. observed the whole of the abdo proposition contained in the followmen to be covered with a web con- ing letter from our Correspondtaining a bubble of air, probably in- ent, Mr. Harvey. We trust that tended for respiration, as it evidently the national interest and importincluded the spiracles. The spider, ance of the information which it is enveloped in this little diving-bell, proposed to bring together, will endeavoured on every side to make make them willing to do every thing its escape, but in vain, on account in their power to render it as accu. of the slipperiness of the glass; and · rate and complete as possible. We 413 ANNUAL RETURNS OF DIECHANICS' INSTITUTIONS. have subjoined to the letter a Form To your most useful Magazine, in which the return may be made. dedicaied so exclusively in its obIt includes columns for two or three jects to the diffusion of sound mechamatters not mentioned by our Cor- nical information among the operarespondent, but which, we are sure tives—the most numerous class by far he will agree with 119, it is important of our active and enterprising comshould also be ascertained. We hope munity-the future investigator of the different returns will be sent to the causes of our unrivalled supeus before Christmas next, when we riority in arts and manufactures will propose to lay a tabular view of the naturally turn, for the materials to whole before our readers.

assist hiin in his magnificent survey. Few surveys, indeed, could present more striking and impressive results.

It would interest both the philanSIR.-It has for some time been thropist and the philosopher; itan object with me to obtain some would form a so

would form a sort of skeleton map authentic account of the number of of the state of useful knowledge Mechanics’ Institutions, and Mecha.

ainong the operative classes, which nics' Book Clubs, now existing in every year would tend to beautify different parts of the country; and

and fill up. it has just occurred to me, that your For want of authentic information very useful Magazine might be made of this kind, if we attempt at any time the means of obtaining this most de- to trace the causes that have led to sirable information, hy introducing

results so interesting to human hapa notice, inviting the Secretaries, or

piness, a3 are daily presented to our other Officers of such Institutions, to contemplation, we soon become enforward to the Editor the names of veloped in uncertainty and error. the societies to which they belong. Let us, however, hope, by the attenTo communicate, however, to such tion that has been latterly awakened a return all the advantages of which to statistical inquiries in this counit is susceptible, it would be inost try, that our successors may not desirable to include in it the number have occasion to say of us, what we of members belonging to each so

sometimes have good occasion to say ciety, the average number of readers of our predecessors. Let us rememwhich attend the libraries or reading- ber, “ that it will equally reflect on rooms, the number of volumes of the present generation, when they, which each library consists, and like the foriner, shall become the the rate of the weekly or annual con- past, unless some means are adopted tributions, brought up to some de

to furnish our successors with those finite period, say Michaelmas, 1825. interesting facts, the want of which Such returns, when collected by the leaves us often enveloped in the Editor, might be tabulated and re- shades of uncertainty and error.*" duced into a systematic form, and

I remain, Sir, printed in the Mechanics' Magazine; thus affording the materials of muclı

Your obedient servant, important information, not only to

George Harvey, F.R.S. the present generation, but to the Plymouth, Sept. 21st, 1825. historian, whose duty it may be, in after ages, to trace the ealises that P.S. The reader is requested to have operated in accelerating the

mark with inverled cummas the Ilth, march of useful information ainong

12th, 13th, and 14th lines, from the the working classes. And if annual

bottom of the second column of the returns of the saine kind could be better in page 315; and also the made, and tabulated according to the 19th, 20th, and 21st, and the five. best form, the successive steps which concluding lines of the second coinark the growth and extension of lumn of page 316. mechanical information might be traced from year to year, and from * Wimpey on Economical Registers, one generation to another.

vol. 1. Manchester Memoirs.

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Sir-The above figure is intended that the leather round the edge of to represent a Section of a Pump, the piston, though only six inches whose pistons, however large, have long, will make a 12-inch stroke, beno friction.

cause it passes from six inches beAAA represent the pump, consisting low to six inches above the junction of three distinct cylinders, screwed to of the cylinders, whose parts at the gether by their flanches, BBB, screw. flanches are made larger for that ing in also leather long enough to purpose, which allows the leather to descend inside-say here six inches; move freely, and also the capacity the other end of this leather, CCC, of the pump to be increased, withto be nailed round a piston of wood, out increasing the bore of the other having a valye in its centre, D, open- parts. Suppose this pump 18 feet ing upwards; two or more working- high, and the pistons six feet asunrods, EEEE, pass through and hold der, then, during the lift, the leaeach piston, as they move up and ther would have rather less than 3lb. down together by the action of the pressure to each square inch, bepump-handle, FF. It is manifest, cause the column of water, 18 feet

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