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CASES IN COTTON SPINNING.

a loaded gun, so as to remove the lead most effectually without injuring the barrel, and whether hot or cold water is best for washing it.

I observe Mr. Wightman states, that a percussion-gun kills ten yards farther than a flint-gun; but I have been told the reverse, both by gunmakers and sportsmen, who asserted that they had made accurate experiments, by trying the same barrel with flint and percussion locks, and that the former had decidedly the advantage in strength of shooting. Mr. W., or any other of your Correspondents, would confer a favour upon sportsmen, if he would give such proof of his assertion on this point, as might settle the dispute between flint and percussion.

Flintshire, May 18th.

HAMMER.

Trial of a Gun with Flint Lock,

133

SIR,-The many and conflicting arguments which are daily held on the merits of the detonating principle, have induced me to trouble you with the following Schedule, which at once proves the superiority of the percussion gun over the common flint. Though my statement differs from a late treatise on guns, shooting, &c. by an experienced shot, I beg to say, that it is the result of many experiments; and I feel confident when I assert, that they will be found correct and impartial observations.

I remain, Sir,
Yours respectfully,

May 20th, 1825.

TELLOC TRIGGER.

Same Gun, with the Detonating Principle appplied to it.

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CASES IN COTTON SPINNING.

SIR,-Being a subscriber to your interesting and instructive miscellany, the Mechanics' Magazine, from which I have derived much instruction (particularly in the articles on geometry), I have for a long time been anxiously expecting to see something more immediately connected with the machinery employed in cotton factories, but have hitherto been disappointed, except in one or two instances. As I am aware there are several of your subscribers in Manchester, and various parts of Lincolnshire, employed as overlookers of different departments in cotton factories, it is my humble opinion that both mechanics, machinists, and overlookers of mulespinners and card-rooms, might add to their own stock of knowledge and

practical experience, and greatly accelerate the improvement of their machinery. And surely no person can entertain so absurd an opinion, as that the art of manufacturing cotton wool into yarn is brought to perfection, but will rather concur with me, that great improvements may yet be made in the construction of the machinery, and in the different operations of cording, drawing, and spinning, by communicating, through the medium of the Mechanics' Magazine, their ideas; proposing and answering difficult questions, stating and solving problems, and showing the correct calculations to regulate the speed,&c. of the various branches, from the carding-engine to the mulespindle. Therefore, in order to stimulate such of my brethren in the trade as are qualified to discuss the

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PRIZE CHRONOMETERS, ETC.

subject, I am induced to send you the following problems and questions for insertion in the Mechanics' Magazine; hoping they will take the hint given by Dr. Gregory in the motto to one of your Numbers (No. 69), and not only send answers and solutions to the subsequent articles, but continue to communicate matter more essentially necessary to be understood by every practical man at the head of cotton factories and machine shops. I know by experience, that there are men at the head of spinning-rooms and cardrooms who neither understand carding, drawing, or spinning, nor the rule to make correct calculations. The consequence is obvious; most part of the yarn is spoiled, being unequal and twisted. When any alteration is required in the system, or the spinning-masters are ordered to charge 20 or 30 hanks per pound, they cannot count to the point within four or five hanks. Such men have imposed on their employers, by pretending to understand the business, agreeing to serve for less wages than they could engage a man properly qualified both in theory and practice. The master does not see his error until he has lost his customers. The following queries may perhaps appear ridiculous to some of your intelligent and ingenious readers, but I can assure them, some of them have puzzled me for several months, before found out the true cause and proper remedy; and I am not certain that much further light may not be thrown upon them.* Hoping this will be the commencement of a series of articles, which may have a tendency to facilitate the improvement of the art of cotton-spinning, I remain, Sir, yours. &c. AN OVERLOOKER.

PRIZE CHRONOMETERS.

SIR,-I take it for granted, that when Government first proposed that Chro

*The queries here alluded to were, by mistake, inserted without this introduction in our last Number, where they will be found under the head of "Inquiries," No. 122 Cases in Cotton Spinning."

nometers should be received upon trial at the Royal Observatory, Greenwich, they meant thereby to encourage the real makers of those machines, and not the mere tradesmen by whom they might happen to be vended. This, however, has not been done; for, last year, a prize was given to Mr. Murray, of Cornhill, and this year, another has been given to Mr. French, of Sweeting's-alley, neither of whom, however respectable they may be as dealers and chapmen, ever made a chronometer himself. To give them the prizes, therefore, or, indeed, to allow any man, who is not known to be a real maker, to compete, is little less absurd, than if the prize were given to the deputy astronomer for that chronometer to which he pays the most attention.

Your publishing this may be the means of procuring justice for

REAL WORKMEN.

Clerkenwell, May 18, 1825.

[We think it is due to truth and justice to insert the above, but hope it will be in the power of Messrs. Murray and French to rebut successfully the charge brought against them.-ED.]

WHY IS A CARRIAGE LIGHTER WHEN IN MOTION THAN AT REST? SIR,-I much suspect, as one of your Correspondents seems half inclined to do, that the question of a Carriage being lighter in Motion than when at Rest, is something similar to King Charles's question about the eels; notwithstanding the fact about skating over thin ice, and the resolution of forces, as explained by G. A. S. It is well known, that when a body moves diagonally under the influence of two forces, at right angles to each other, each impulse preserves its full effect, when estimated in a line parallel 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 curve it is thus compelled to describe, is just as great as if it were at full liberty to fall, by that projectile force being withdrawn. Upon this property the calculation of the true balance of these powers is made. If a cannon-ball be projected horizontally, with a velocity of ten feet, over a high cliff, at the end of the first second it will be found ten feet from the cliff, and about ten feet below it; at

WHY IS A CARRIAGE LIGHTER WHEN IN MOTION THAN AT REST? 135

the end of two seconds it will be found at
twenty feet from the cliff, and sixty-four
feet below it; and thus it will appear,
that both powers operate without either
diminishing the other. If any one will
examine thin ice breaking under too
heavy pressure, he will perceive that it
is a progressive, and not an instantaneous
action. It bends first to a considerable
extent, and receives an additional sup-
port from the water thus displaced under
it, like a shallow boat; the pressure con-
tinuing, it begins to crack in lines, ra-
diating from the point where the force
is exerted; when these have proceeded
to a sufficient extent to have leverage
enough, notwithstanding the counter-
acting increase of width of the pieces in-
tercepted between these radii, the whole
breaks in by a fracture nearly circular.
In proportion as there is a greater dispa-
rity between the force applied and the
resistance, this process goes on with
more rapidity; when the powers are
nearly balanced, I have seen ice sustain
weights for a second or two that it broke
in with; in fact, the process of break-
ing occupied this time. Hence, if a man
skating over ice too thin to sustain his
weight resting long upon it, quits his
place continually before the process is
completed, he does pass over ice that
may be said to be too weak to sustain
his weight; but the fact arises from the
slow, counteracting process, and no
other cause. Time is a necessary ele-
ment in all calculations of force. A shot
will cut a piece out of a board suspended
by a string, and scarcely stir the board;
thus the firm attraction of the particles
of the wood give way, apparently with-
out effort, because attraction is a thing
measured by the time it operates; but it
is equally effective during every portion
of it, and the amount of the whole in a
given time is a given sum. If a carriage
occupy one second in going over the flat
board of a weighing-machine, it will
distribute as much pressure over the
whole length as it would have applied to
any one point of it, on which it stood
still during the same time. Hence I con-
ceive the Carriage Question may as well
rest as be kept going.
am, Sir,

Your obedient servant,

G. C.

ON THE SAME QUESTION. From another Correspondent. SIR,-It is a well-known principle in mechanics, that when two bodies impinge against each other, the mutual actions of one body against the other are invariably equal. By this action the parts of the bodies yield inwards, but imme

diately return to their figure by their natural elasticity.

For instance, if a body, B, whose velocity is 12, impinge against A, in a state of rest, and whose mass is to that of B as 3: 1, the direction of the motion originally impressed upon the body, B, will be changed after the stroke, and it will return with the velocity of 6. In this instance we suppose B and A to be perfectly elastic; but as we are unacquainted with any bodies possessing this quality in so perfect a degree, allowance must, of course, be made in speaking of natural bodies; those which approach the nearest to this perfect state of elasticity, admitting more immediately of the application of the general rule.

We will endeavour to apply this rule to the question under consideration. When the ball is in a state of rest upon the weigh-bridge, the latter body, after the elasticity generated by the first impression (viz. the impression exerted by the ball in the act of being placed upon the bridge) has subsided, is then acted upon only by the force of gravity, which acts equally and every moment of time near the earth's surface.

If the ball be thrown down upon the bridge with the velocity of 12, the mass of the bridge being to the mass of the ball as 31, the ball will rebound, and return with the velocity 6 (supposing the force of gravity suspended); but supposing the force of gravity existing, it must be subtracted from the last-mentioned velocity.

In this case it is evident, that immediately after the stroke, and during the action of elasticity, not only is the force of gravity insensible, but absolutely overcome, and a motion impressed upon the ball in a direction contrary to the first.

This case is easily applicable to that of the ball rolling over the bridge, the motion of which may be considered as a succession of strokes, the momentum of each being equal to the force of gravity.

If the velocity of the ball generated by gravity, for argument sake, be supposed equal to 12, and the masses bearing the same proportion as above, gravity would then, of course, be insensible, and the bridge would be under no impression; but as neither of the masses bear this proportion, or the velocity of the ball the same as above, the general result must, of course, be different.

It is upon this principle that a carriage suspended on springs moves with less resistance over a road, than would a carriage of like bulk without springs. I am, Sir, Your obedient servant, H. W. B. N, Woolwich,

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IMPROVEMENT OF WHEEL CARRIAGES.

tleman to give his advice on the same invention, and that one of us must have borrowed it from the other. This, however, proved not to be the case; and, on more minute examination, there appeared a considerable difference in the mode of constructing the American engine, though acting on the same general principle as my own. From that time to this, I believe neither of these engines have ever been applied to any use, though a patent was obtained for the American engine, which was, I think, the best of the two, if used with water only. I conceive, however, that these engines are so simple in principle, and so cheap and durable, that, on many occasions, if generally known, they would be applied with great advantage. The power of them is derived from the tendency of light bodies to float when immersed in heavy fluids, or, to speak more correctly, of the heavy fluids to displace them.

Fig. 1 exhibits a wheel divided into cells, and placed under heated mercury, or that mixture, of eight parts of bismuth, five lead, and three tin, which is fluid at the temperature of 2120; or, where waste of fuel and loss of space are no great objects, placed only under boiling water. Each of these cells is connected by any appropriate means with a steam pipe, so that each receives the steam; when at the bottom, the floating power then brings the other cells in succession to be filled with steam, and the wheel is thus put into full action. Where the expansive force only is used, the steam escapes from the top of the trough; but if this be connected with a condenser and airpumps, as usual, the full power will be obtained with the metallic fluids. Each cubic foot of steam, in water, will give about 60 pounds of power; in the metallic mixture, about 600 pounds; and the velocity with which this supply can be afforded, and the height it can rise, will give the remaining elements for calculating the power of the engine. As the steam will expand as it rises up in the buckets, no more should be allowed to enter than will fill them when at the top of the wheel. The metallic mixture is subject to oxidation by

137

the hot water, in some degree, but it may easily be restored again, by melting the oxide under tallow. When water only is used, the whole machine may be made of wood, in the form of a common bucket water-wheel; a steam pipe is introduced through the bottom of the trough, just under the side of the wheel where the buckets are inverted, when they become filled with steam in succession, and thus a stream of steam effects as much, bulk for bulk, as a stream of water. This is the form of the American engine.

Fig. 2 is a plan for admitting the steam into the pipes leading to the cells, but many better modes might be adopted; this is, however, sufficient to explain my engine. It is scarcely necessary to mention, that the steam tubes should be covered up by circular plates on each side of the wheel, to obviate the resistance in passing through the fluid.

I remain, Sir,
Your obliged servant,

G. C.

IMPROVEMENT OF WHEEL CAR-
RIAGES.

SIR,-Your Correspondent signing himself R. E. (p. 103, vol. iv.) inquires, whether any benefit would be derived by a horse in drawing a gig by shafts, connected to the other part of the carriage by a resisting spring, in order, as your Correspondent says, "to relieve him at starting, and on meeting with any obstructions on the road." Now, Sir, I apprehend the very reverse of ease would be the consequence of such an alteration; as the horse would then have to overcome the resistance of the spring, in addition to that of the carriage, and his whole labour would be further increased by the unsteady purchase it would create. My ideas for an improvement in the draught of gigs, would suggest an immediate connexion of the shafts to the axle-trees, thus dispensing with traces; and by allowing the line of draught to be quite straight, and at a proper angle, it would tend to prevent much useless

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