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130
PERPETUAL PUMP ON THE SLIDING RULE.

Fig. 2 is a vertical or bird's eye
PERPETUAL PUMP.

view of the machine, with its axle Sir, — Travelling in a distant lifted off the gudgeons. country, I observed, by the road- . I think this method is making the side, a horse-trough flowing over, most of a stream of water, if it can being fed by a spout continually run. have a foot fall, and, to all residents ning : this spout was supplied by a near brooks or small streams, it will Perpetual Pump, in a very small be found highly convenient and

ledge.

distant, which I went to examine, to fill cisterns, reservoirs, or ponds, and found it to be a contriyance so above the usual level, &c. as the extremely simple in itself, and so water may be carried to any height useful in effect, that I take the op- at pleasure. portunity of sending a description

I remain, Sir, of it to you, thinking it may be a lover of practical mechanics, and, worthy of a place in your valu

of course, a well-wisher to your able repository of mechanical know

original and valuable pub-
lication,

VIATUR. The figure is so simple, it scarcely Kimbolton. requires explanation. By the rough sketch prefixed, it is clearly perceived that two or more boards are ON THE SLIDING RULE." placed across the stream, and held Sin.-Some time since I endeaup by five or six stakes driven into

voured to explain the construction the stream perpendicularly, and

and application of Gunter's Line, nailed to them : in the upper board

and should have extended the subject (not exactly in the middle of the

to the use of the same lines, as enstream) is cut a notch for a spout,

graven on the Sliding Rule, had I not through which the whole of the

i thought that some of your practical brook or stream is conducted, and

ana Correspondents would have been in

C passes over as a spout into a sort of duced to

of duced to take up the subject where oblong box, whose outer end is Ule

I left it, as I am confident that those formed somewhat like a shovel; when who are in the daily use of this inthis is full, it overbalances the stones

strument, are much more competent on the other side of the pivot, and,

to give a familiar explanation, suited descending, instantly empties itself,

to the capacities of workmen in geand is as instantly brought to its

neral, than I can be. However, as I former level by the stones in the

find myself called upon by your frame on the opposite end. This

Correspondent, “Monad," and alprocess is repeated every time the ways feeling desirous of lending my stream fills the box, the frequency

assistance, when I have it in my of which, of course, depends upon

power, towards the elucidation of the magnitude of the stream; in the

any subject that may benefit the machine I saw, it was about twice a

mechanic, I shall proceed to give minute. As the crate of stones rises, such a description of the instrument it lifts up the rod affixed to the that, I trust, will enable any one to pump handle, and when the water estimate its utility, and apply to on the other side is emptied, the

practice Gunter's Line, as adapted weight of the stones pulls down the

to the art of measuring by the slidpuinp handle, and so keeps con

ing rule ; and I trust that my ready stantly performing. A continuation

acquiescence to the wishes of Monad of troughs or gutters conveyed it to will induce him to favour your readthe place required, where it never

ers with the use and application of ceased running, fully answering its the sectoral lines, as applied to menintended purpose.

suration and mechanics, as also the Two stakes are driven in the stream, method of their construction. for the axles of the machine to rest I shall now proceed with the subon, as in the figure.

ject, first remarking, that the term

ON THE SLIDING RULE.

131 “slide rule" is applied to a variety ten equal parts, which answer to the of instruments known under that tenth part of a foot, and then these title, such as Partridge's, Hunt's, parts are subdivided again into ten Everard's, Coggershall's, &c. ; but equal parts also, which answer to the that most commonly in use is Cog- hundredth part of a foot; and thus gershall's, and known by the gene we have the foot decimally divided, ral term of the carpenter's two-foot (and which, by-the-bye, we have to slide rule; and as that is the most regret is not the general practice, simple, I shall give its use and ap- as it would much shorten calculaplication previous to that of some tion, and be less burdensome to the others, which are adapted to other memory than the present system of purposes than performing the rules dividing the foot into twelve equal of multiplication, division, and ex- parts). These decimal divisions on traction of roots. First, then, the rule are continued along the two

legs of it, and thus we have the Of the Construction of the Slide Rule. whole length of two feet divided into

This instrument consists of two 200 equal parts. pieces of box wood, each a foot in We now proceed to the other face length, and connected together by a of the rule, and which it is the chief brass rule joint; one side or face of object of this paper to describe. One the rule is divided into twelve inches, leg contains a continuation of the and numbered; when the rule is scales for planning, from one quarter open from 1 to 24, each inch is also of an inch to one inch to the foot: subdivided into halves, quarters, and on the other leg is the division more eighths (or half-quarters), the use especially under our consideration, of which speaks for itself; the re- and which I shall endeavour to mainder of this side of the rule is describe as familiarly as possible, taken up in general with scales for that their nature, being well underplanning dimensions. The rule I stood, will contribute to the thorough have before me contains only two knowledge of their use and appliscales on this face, the one an inch cation. On this face are four lines, and a quarter scale, and the other marked A, B, C, D; the three upan inch and a half; each of the large permost of which, marked A, B, C, divisions, in drawing or measuring are exactly similar to the lines on plans, are called feet, and one of Gunter's scale, being the logarithms these divisions in each scale is divided (or artificial numbers) from one to into twelve equal parts, correspond ten, twice repeated (see the descriping to inches on the plan. The use tion of this line, page 157, vol. 111. of these scales is so obvious that of this Magazine), and which it is, it needs no illustration ; but, for therefore, unnecessary here to dethe sake of the young draftsman, I scribe. The first of these lines, A, shall merely state that, in laying is engraven on the rule itself; the do:vn a plan of any building or piece two next, B and C, are engraven of work on paper, suppose he wishes on a brass or wood slider, and are to represent the distance of five feet exactly similar to the line A; and six inches, he has nothing to do but these three lines are called double to take from the scale a distance lines, as proceeding from unity to between the compasses equal to five ten, and twice repeated : the fourth of the large divisions and six of the line, marked D, is a single logarithsmaller, and draw a line of that length metic line (similar in its properties on his paper; and if he wishes his to the other lines), and is the repredrawing to be of such dimensions sentation of the logarithms of the that one foot of the work required numbers, the proportional lengths of to be executed shall be represented which are double those of the lines on the paper by an inch and a half, A, B, and C, thus answering to cubic he must use the scale marked it measure or solid content of bodies; and so of all the other scales. whilst the other lines, A, B, C,

We will next observe that the thin answer to superficial measurement, edge of the rule is divided into, first, as it is well known that the logarithm

132 FLINT AND DETONATING LOCKS-CLEANING LOADED GUNS. of a number, multiplied by two, re- guns of different calibres; but as presents the logarithm of the square you mention that the quality of the of the number that the first logarithm barrel makes a material difference in represented. This line, D, is also the charge, I beg you will add how called the girt line, from its use in you discover this difference. It strikes finding the content of round tim ber me, that if two barrels are the same or trees, by taking their circum- in length and bore, and straight, that ference round with a string, as in they must require the same charge, the common method in use, though whether the barrels be made of it must be allowed it is not very welded needles, or hoop-iron, or castexact.

iron, or brass. Again, I do not see In the use of this rule it will be why a barrel should shoot the better necessary to bear in mind, that when for being thick; that is, a barrel 1, at the beginning of any line, is as thin às writing-paper should shoot accounted 1, the I in the middle as well as a barrel half an inch thick, must be reckoned 10; and when the provided the force of the powder do · 1 at the beginning is reckoned 10 or not make any permanent alteration in

100, the I in the middle must be the size of the bore. I understand reckoned 100 or 1000, and so on, it is usual to enlarge gun-barrels (to and all the other divisions in the shoot shot) towards the muzzle, to same proportion.

make them shoot close, as well as to

G. A, S. enlarge them at the breech, to make (To be continued.)

them shoot strong. It would materially add to the value of your tables, and I will thank you to inform me if

this practice is usual, and to point ON FLINT AND DETONATING LOCKS

out how much larger or smaller at SHAPE AND QUALITY OF GUN

the muzzle and breech, barrels may BARRELS CLEANING LOADED

be inade to advantage; as also how GUNS, ETC.

much barrels should increase in Sir,--Telloc Trigger, in Number length and weight with their in90 of your - Magazine, describes a creased bore, beginning with a halfgun to be seen at Blanch's, gun inch barrel, and increasing one quarmaker, as an invention“ surpassing ter of an inch at a time, until you all others,” &c. Neither *Telloc reach a two-inch swivel duck-gun. I Trigger nor yourself were probably will trouble you also for a good pracaware, that a Frenchman, of the tical rule, to prove whether a barrel name of Pauly, claims the invention is perfectly straight or cylindrical in he alludes to. Guns, rifles, and piss the inside. tols, are now made at Paris on this In your tables you give a charge plan, either to load at the breech or for sixty yards. I have always unmuzzle. They are liable, however, derstood that the best guns should to several objections; in particular, not be depended upon to hit, that is, they are not water-proof, as the rain to put one grain of shot into a comruns down the barrel through the mon playing-card at forty yards. hinge, and wets the detonating Perhaps you will mention how many powder.

grains can be put into a mark of that As I suppose, Mr. Editor, your size, or a circle of six inches diameobject is to give information to the ter, at sixty yards, and the sized public in your Magazine, and not to shot. publish bare assertions, I send the

I am, Sir, above, and enclose also a few remarks

Your obedient servant,
to your Correspondent, Mr. E.
Wightman, Malton.
To Mr. E. Wightman, Malton.'

Sir, I should be much obliged SIR-In your answer to Number to your valuable Correspondent, Mr. 97, Questions on Gunnery, you give Wightman, if he would inform me a table of proportional charges for what is the best method of cleaning 133

CASES IN COTTON SPINNING. a loaded gun, so as to remove the SIR, The many and conflicting lead most effectually without in- arguments which are daily held on juring the barrel, and whether hot the merits of the detonating princior cold water is best for washing it. ple, have induced me to trouble you

I observe Mr. Wightman states, with the following Schedule, which that a percussion-gun kills ten yards at once proves the superiority of the farther than a flint-gun; but I have percussion gun over the common been told the reverse, both by gun- Aint. Though my statement differs makers and sportsmen, who asserted from a late treatise on guns, shootthat they had made accurate expe- ing, &c. by an experienced shot, I riments, by trying the same barrel beg to say, that it is the result of with flint and percussion locks, and many experiments; and I feel conthat the former had decidedly the fident when I assert, that they will advantage in strength of shooting. be found correct and impartial obMr. W., or any other of your Corre- servations. spondents, would confer a favour

I remain, Sir, upon sportsmen, if he would give such proof of his assertion on this Yours respectfully, point, as might settle the dispute

TelloC TRIGGER, between flint and percussion.

May 20th, 1825.

HAMMER. Flintshire, May 18th.

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practical experience, and greatly acCASES IN COTTON SPINNING.

celerate the improvement of their Sır,-Being a subscriber to your machinery. And surely no person interestingand instructive miscellany, can entertain so absurd an opinion, the Mechanics'Magazine, from which as that the art of manufacturing cotI have derived much instruction (par- ton wool into yarn is brought to perticularly in the articles on geometry), fection, but will rather concur with I have for a long time been anxiously me, that great improvements may expecting to see something more im- yet be made in the construction of the mediately connected with the ma machinery, and in the different opechinery employed in cotton factories, rations of cording, drawing, and but have hitherto been disappointed, spinning, by communicating, through except in one or two instances. As the medium of the Mechanics' MaI am aware there are several of your gazine, their ideas; proposing and subscribers in Manchester, and va- answering difficult questions, stating rious parts of Lincolnshire, employed and solving problems, and showing as overlookers of different depart. the correct calculations to regulate ments in cotton factories, it is my the speed,&c. of the various branches, humble opinion that both mechanics, from the carding-engine to the mulemachinists, and overlookers of mule- spindle. Therefore, in order to stispinners and card-rooms, might add mulate such of my brethren in the to their own stock of knowledge and trade as are qualified to discuss the

134

PRIZE CHRONOMETERS, ETC. subject, I am induced to send you nometers should be received upon the following problems and ques. trial at the Royal Observatory,Greentions for insertion in the Mechanics' wich, they meant thereby to encouMagazine; hoping they will take the rage the real makers of those mahint given by Dr. Gregory in the chines, and not the mere tradesmotto to one of your Numbers men by whom they might happen to (No. 69), and not only send answers be vended. This, however, has not and solutions to the subsequent ar- been done ; for, last year, a prize ticles, but continue to communicate was given to Mr. Murray, of Cornbill, matter more essentially necessary to and this year, another has been given be understood by every practical to Mr. French, of Sweeting's-alley, man at the head of cotton factories neither of whom, however respectand machine shops. I know by ex- able they may be as dealers and chapperience, that there are men at the men, ever made a chronometer himhead of spinning-rooms and card- self. To give them the prizes, thererooms who neither understand card- fore, or, indeed, to allow any man, ing, drawing, or spinning, nor the who is not known to be a real maker, rule to make correct calculations. to compete, is little less absurd, than The consequence is obvious; most if the prize were given to the deputy part of the yarn is spoiled, being astronomer for that chronometer to unequal and twisted. When any als which he pays the most attention. teration is required in the system, or Your publishing this may be the the spinning-masters are ordered to means of procuring justice for charge 20 or 30 hanks per pound,

REAL WORKMEN. they cannot count to the point within

Clerkenwell, May 18, 1825. . four or five hanks. Such men have imposed on their employers, by pre- [We think it is due to truth and tending to understand the business, justice to insert the above, but hope agreeing to serve for less wages than it will be in the power of Messrs. they could engage a man properly Murray and French to rebut successqualified both in theory and prac- fully the charge brought against tice. The master does not see his them.--ED.] error until he has lost his customers. The following queries may perhaps appear ridiculous to some of your WHY IS A CARRIAGE LIGHTER WHEN intelligent and ingenious readers, IN MOTION THAN AT REST? but I can assure them, some of them SIR, I much suspect, as one of your have puzzled me for several months, Correspondents seems half inclined to before I found out the true cause do, that the question of a Carriage being

lighter in Motion than when at Rest, is and proper remedy; and I am not

something similar to King Charles's quescertain that much further light may

tion about the eels; notwithstanding the not be thrown upon them.* Hoping fact about skating over thin ice, and this will be the commencement of a the resolution of forces, as explained by series of articles, which may have a G.A.S. It is well known, that when a tendency to facilitate the improve

body moves diagonally under the intiument of the art of cotton-spinning,

ence of two forces, at right angles to

each other, each impulse preserves its I remain, Sir, yours. &c.

full effect, when estimated in a line paAN OVERLOOKER. rallel to its former direction. Hence the

teudency of the moon to fall towards the earth in its orbit, though sustained

there by the projectile force, and the PRIZE CHRONOMETERS.

curve it is thus compelled to describe, is SIR,-) take it for granted, that when

just as great as if it were at full liberty

to fall, by that projectile force being Government first proposed that Chro withdrawn. Upon this property the cal

culation of the true balance of these * The queries here alluded to were, by powers is made. If a cannou-ball be promistake, inserted without this introduce jected horizontally, with a velocity of ten tiou in our last Number, where they will feet, over a high cliff, at the end of the be found under the head of “ Inquiries," first second it will be found ten feet from No. 122" Cases in Cotton Spinning." the cliff, and about ten feet below it ; at

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