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GRYLL'S IMPROVEMENTS IN WINDLASSES, CAPSTANS, AND CABLE STOPPERS.

Sir,-It has long been a desideratum to find some means of obviating the delay and danger in heaving up ships' anchors and cables, arising, from what in nautical parlance is called “surging" or "fleeting over;" and although several patents have been taken out for this purpose, and many ingenious designs for improvements in windlasses have been described in the earlier volumes of your Journal, I have not met with one which fulfils all the requisite conditions so well as that which I am now about to describe.

By the old methods, whenever a cable was being "hove in," an operation which often requires to be done with the utmost expedition, when the chain or cable had made three or four turns round the barrel of the windlass, it would work to the higher end, or that of greatest diameter, and then immediately require "fleeting over." To effect this, a strong iron claw usually affixed to the "bitts" was passed over the chain, and the strain being transferred from the barrel of the windlass to the bitts, the chain was slacked and passed over to the lower end, or that of least diameter-both a dangerous and tedious operation, and one which, when riding in deep water, required to be frequently repeated.

In Gryll's Windlass, the "fleeting over" is entirely dispensed with, by a very simple contrivance. On the barrel are firmly bolted, what the inventor calls "Whelps," consisting of strong iron plates, forming a double-inclined plane, at the base of which the chain is found to "bight," or hold on securely, and has at the same time no tendency to work up either of the inclines, but keeps steady while getting the anchor."

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One of the most disagreeable duties a sailor has to perform, is thus rendered speedy and safe; to say nothing of the saving which will be effected to the owners of ships by the lessening of the wear and tear of rope under the old sys

tem of "jerking" or "swinging." Another thing which will also be greatly reduced, if not entirely done away with, is the strain on the vessel which was caused by transferring the strain from the barrel to the top of the windlass, which rendered the forecastle of many vessels leaky in consequence of the coming up, as it is called, causing an opening of the seams.

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The improvement in the capstan consists in substituting whelps of the same kind as those applied to the windlass, for the ordinary straight barrel.

The plan for stopping the cable appears to me to be a decided improvement. By giving a longer grip-hold on the cable, and allowing the leverage to be increased or diminished as required, it will be perceived, that great advantages are obtained.

The East India Company have adopted the windlass and stopper in all the ships recently fitted out by them.

Description of the Engravings.

Fig. 1 is an elevation of the windlass, in which the old and new plans are contrasted. A A, the patent whelps, bolted to the barrel, over which the chain is passed; B B, barrel of windlass on the old plan.

Fig. 2 is an elevation of a capstan with the whelps applied.

Fig. 3, front and side views of the whelp for windlass.

Fig. 4, front and side views of the whelp for capstan.

Fig. 5 is a view of the improved stopper fitted to a large ship, and placed under the gun deck. By bringing the lever A to a horizontal position, the stopper B, will be made to press upon and jam with great force the cable.

I am, Sir, your constant reader,
E. WHITLEY BAKER.

London, August 22, 1842.

PROGRESS OF FOREIGN SCIENCE.
Communications to the Royal Academy of France.
Railway Accidents-Fracture of Axles.

1. M. Séguier proposes, in a paper communicated to the Academy, to account for the fracture of the fore axle of

the first locomotive, which produced the accident on the Versailles Railway, by referring it to the variable and continuous

shocks to which this axle is exposed in all four-wheel engines, by reason of the point of traction and the point of adhesion of the wheels upon the rails not being in the same right line.

From the usual arrangement of fourwheel engines, it is habitual to advance with the loose wheels foremost, i. e. the driving-wheels behind; the loose wheels are therefore pushed on.

"But the effort of a locomotive is produced by the adhesion of its wheels against the rails, in a plane tangential to the moving wheels. The tractation of the engine is transmitted to the train by the points of attachment of the engine and tender to the train, in another plane placed above the former by the whole diameter of the wheels: hence, it inevitably results from this arrangement, that the plane in which the resistance acts tends to approach that in which the traction is exercised, that is to say, that the whole mass of the locomotive has a continual tendency to upset backwards, or to turn over round a point which is the centre of the driving-wheels." By reason of this, it sometimes happens that the fore axle of the engine is discharged of a great part of its load, (which at the greatest, when stationary, is only one-third of the engine;) while at other moments, by the advance of the train, and its pushing the engine from behind, this same axle is exposed to a more than ordinary stress, (by the inversion of the forces before described;) and from inequalities in the road and in the moving force, these alternate pullings and pushings are continually taking place. To this cause the author ascribes the fracture of the axle on the Versailles Railway. He does not enter into the question of the advantage of four or of six wheels; but considers that such arrangements might be made in the four-wheel engine, as would enable the driving-wheels to be in advance, and thus at once get rid of the foregoing cause of unequal strain, but also of the tendency to run off the rails, which the wheels in advance in four-wheel engines, as now made, being pushed in place of pulled, must always subject them to.

M. Séguier concludes by stating, that he will shortly lay before the Commission of the Institute a method by which he considers it possible, by an application of M. Dobo's mode of rectilineal brake, to obtain from the weight itself of the masses moved the most effective means of destroying, progressively, their acquired velocity.

2. The next communication we have to notice is one by M. François, Mining Engineer, entitled, "Note on the mole

cular changes which are produced by use in iron exposed to strains, (pieces de resistances,) and especially in axles; on the manufacturing of these; and on the means of preventing these changes." This paper is far from clear in its views or expressions, and it may be doubted how far it is even correct in fact.

The author considers wrought-iron as a mixture of pure metal and certain imperfectly reduced metallic slags, of definite chemical constitution, which he calls the "silicate multiple neutre." He affirms that these crystallize in the substance of the iron, in obedience to certain undefined thermo-magnetic forces. When a bar is first rolled, it sustains a powerful magnetic excitement; if it be again heated, it loses this, and the silicate and metal are now found, on microscopic examination, uniformly diffused as an amorphous metallic paste, with a structure pseudo reticular; but if the bar be submitted to any of the following operations—

1. Tempering, or sudden change of temperature;

2. An unequal heating, or a weld in the direction of its length;

3. Successive blows; friction of all sorts; 4. Electric discharges;

5. The action of an electric current, or of a magnetic armature;

6. Leaving it to repose near the surface of the earth, and especially in a position perpendicular to the magnetic meridian.

Then the molecular structure suffers the following changes, according to the energy of these actions, and the temperature at which they act. The amorphous structure of the silicate, and the pseudo-reticular one of the iron cease; and we find following the axis of figure of the piece of iron, baccillary crystals of neutral silicate; these crystals present many easy cleavages, but principally at a small angle with the axis of the prism. In addition, the metallic portions are no longer equally diffused in the vitreous paste; they show a marked tendency to group themselves in bundles, following the axis of the poles of the crystals: thus, the metallic paste presents a phenomenon of crystallization, with pastiness analogous, up to a certain point, to the fact of the rhomboidric crystallization of the sand-stone of Fontainebleau.

If we examine, after use, the structure of strained pieces, and especially of mail-coach axles, or those of large wagons, originally of fibrous iron, (fer nerveux,) we see at once, following the axis of figure in the middle and at the origin of the rounded parts, baccillary crystals of silicate, empasting the

fusiform parts of the metallic iron, grouped particularly parallel to their axis. Hence the phenomena of facetted structure which broken axles present, &c., &c.

To prevent this taking place, the author proposes

1. To reduce, by a strong welding heat, with pit-coal, the relative quantity of vitreous paste, which, in ordinary iron, often is as much as 007 of the total weight.

He proposes also to use for axles scrapped iron, ("vieux fers et riblons.")

2. To struggle against the forces which induce (provoquent) the prismatic and fusiform structure following the axis of the figure!!

3. To destroy, as a last operation, every modification of molecular structure resulting from the working in the fire and under the hammer, by a simple reheating to a dull red heat, of which the immediate effect is, to reduce the vitreous mass to the amorphous state, and to reestablish the pseudo reticular structure in the metallic particles.

This last remedy can always be employed efficaciously to restore to their state of primitive solidity, pieces whose texture has been altered by use.

The foregoing is almost a translation of this document, which presents an admirable specimen of the talent in which Frenchmen are so peculiarly happy, of slurring over a difficulty, and raising a fog of hard and meaningless words about a subject which, while they do not understand, they will not admit their ignorance of.

All that can be gathered with any distinctness from this paper of M. François is matter known to every intelligent blacksmith in Britain, and probably in France too, although much of it has recently been brought before the public with much pretension to novelty, by Mr. Hood and Mr. Nasmith. It has long been well known, that violent change of external form given to iron, in whatever way, if below the temperature of a bloodred, makes it brittle, and also that its toughness may be fully restored by annealing, or heating up to the blood-red, and slowly cooling; but beyond this, or upon what this phenomenon depends, there is as yet no knowledge. Further, it is certain that this change cannot be produced by any change of form which is not permanent, i. e., by any bending, or indenting, or vibration which is with

in the elastic limits of the material; and hence there does not seem to be any foundation whatever for the assumption, that railway or other axles change their interior structure while in use. Thus far it is clear that, as yet, no case has been brought forward of any axle or revolving shaft, or other such piece of iron, the structure of which has been found, when broken, to be crystalline, and of which it could with certainty be affirmed that it had ever been otherwise-had ever been fibrous; on the contrary, there is every reason to believe that the broken axles exhibited to the Mechanical Section of the British Association, at Manchester, &c., had never been in structure any thing else but crystalline, from the time when they were forged, and when this structure was conferred upon them by swaging until nearly cold.

Sudden change of temperature seems more or less to affect the state of arrangement of the particles of all metals, (as well as other bodies,) sometimes making them harder and denser, sometimes softer and less dense; but evidence is as yet wanting that magnetism is capable of producing the slightest effect of the sort, or electrical discharges or currents. On the contrary, as regards the latter, it is well known that when a hard iron pin, as it comes from the draw-plate, has been heated red-hot by a voltaic current, it becomes soft, just as if annealed in a common fire, and equally as tough. It will be observed that the grand recipe of M. François for curing this diseased iron consists in annealing it. This was well known before; but as the very same thing has since been proposed, with all the air of a new discovery, by Mr. Nasmith, in the Mechanical Section of the British Association, in June last, and since in the Civil Engineer and Architect's Journal, for September, it may be remarked that M. François' paper was published in Paris on the 30th of May last. The subject, if considered in a really scientific aspect, without the desire to hide our ignorance, or pretend to discovery, is one of great curiosity and some importance; and hence it has not been amiss that the British Association, at its last meeting, devoted a large sum of money to researches upon the question: but this money will be grievously wasted, and the time of the experimenters likewise, if squandered upon costly experi

ments to find out whether railway axles, that have neither been bent nor overheated, suffer some change of structure by merely turning round in their bearings under their load.

3. A communication follows from M. Delessert, in which he gives an extract of a letter from Mr. Prevost, an officer on the London and Birmingham Railway, giving an account of the experiment made on that line by Mr. Bury and others, and intended to demonstrate the superiority of four-wheel engines, in which such an engine, with a broken axle, which had purposely been cut nearly through, was caused to travel some miles upon the railway, and ran off the rails; but, as a full account of this singularly ill-contrived and inconclusive experiment has already appeared in the pages of the Mechanics' Magazine, there is no need to repeat it here.

4. The next communication, however, is of more importance, and, as coming from M. Pambour, seems worthy of translation nearly complete: it is entitled "A note on the dispositions most suitable for diminishing the serious consequences of accidents on railways.

"As to the question of whether it is better to perform traffic with a single locomotive and a light train, or with two locomotives and a double train, we have stated that, when a train is drawn by two engines, if an accident occur to the first, about one-half the train will be involved in the accident, but that the remaining half will run no risk, but will be in the same condition as if it had been drawn separately by a second engine; and that if the accident happen to the second of the two engines, the accident, which would be disastrous if there were but one engine to the train, will not be followed by any ill result, because the broken engine, being preceded by the other, will be kept up and upon the line; hence, it is of advantage to employ two locomotives to a train.

"It is true that, if the accident happen to the second engine, it can be foreseen or provided against; but if the accident occur to the foremost one, it will be much more serious than if the train were separated into two, inasmuch as the shock will be twice as great, the weight of the train being twice as much; and so as was the case on the Versailles Railway, the carriages, pushed one by the other, become piled on top of each other, and simple blows become converted into dreadful wounds, without considering the fact, that on an embankment or a viaduct the whole train is destroyed, instead of

only one-half, as when divided between two engines. Thus, the preceding argument in favour of trains with two engines would be of force, were it not that they produce, themselves, chances of accident which do not exist in the case of isolated engines.

"But we know that nothing is more dangerous than to push before us one or more carriages, because the action of pushing the carriages tends to give them a diagonal, or zig-zag motion upon the way. If we push a train with some velocity, there is great chance of one of the carriages going off the line; and this chance is greater in proportion as the train is longer and heavier, and the required force greater.

"Now, if two locomotives are attached together, it frequently happens that the second engine pushes the first, and its tender, before it. This contingency will arise whenever the fire is neglected in the first enginewhenever, on account of signals, the first engine-driver slacks his speed before the second is aware of it-whenever the first engine encounters rails badly laid, or a crossing, or enters on a curve, or passes from a declivity to a level, or thence to an acclivity -in all these cases it is clear that the foremost engine will be partially stopped, and will present an obstacle to that behind; and at these moments the former, with its tender, will be struck by the hinder engine, and pushed on before it: it is clear, therefore, that the connexion of two engines produces dangers which do not otherwise exist."

THE PARIS AND VERSAILLES RAILWAY ACCIDENT-NEW AND AUTHENTIC PAR

TICULARS.

Sir,-The accident of the 8th of May last, on the Paris and Versailles Left Bank Railway, having excited much discussion in the Mechanics' Magazine and other journals, both with reference to its cause and to the means of preventing such accidents in future, I will, with your permission, lay before your readers a few circumstances connected with the accident, some of which I collected on the spot, and others in Paris, which place I visited soon after the accident.

I am induced to do this, as much misunderstanding of the facts of the case has been shown to exist on the part of most of those who have written on the subject; and the discussion, as appears by your journal for August, is very likely to be continued for some time longer.

Soon after my arrival in Paris I visited the Left Bank Station, and saw the

remains of the two engines that were attached to the train to which the accident occurred. They were both small engines; the four-wheeler had 10 or 11 inches cylinders, and the six-wheeler 12 inch cylinders; the stroke in both, I believe, was 18 inches.

The four-wheel engine was destroyed, and the six-wheel engine would require new framing, and other expensive repairs. Both tenders were past repair; the fore and hind axles of the six-wheel engine and those of its tender were very much bent, most of which bending, probably, took place when the axles were very hot. The wheels appeared but little injured.

I learned at the station that the Left Bank Railway Company never had more than three four-wheel engines, and one of them, made by the late Mr. Hicks of Bolton, was employed as a stationary engine to turn the lathes and other machines used in the repairing-shop.

At the Right Bank Railway, I was informed that on that line there were six four-wheel engines, but they were considered so much more liable to accident than six-wheel engines, that none of them had been used on that railway for twelve or eighteen months before the accident occurred on the Left Bank Railway.

On arriving at the spot where the accident took place, and standing on the common road where it crosses the railway, the first thing that struck me on looking along the line in the direction of Versailles, was the very sinuous state of the right-hand rail, of the right line of rails; I immediately called the attention of a friend, (a very intelligent French engineer) who was with me, to the fact, when he informed me, that one of the engineers appointed by the Government to investigate the circumstances connected with the accident, had discovered that the four-wheel engine had gone off the rails, say one hundred to one hundred and fifty yards before arriving at the place where it turned over, and that the axles could not have been broken, or even much bent, until the engine nearly reached the place where it broke down.

The evidence which led to this conclusion, was this:-From the place where the engine ran off the rails, to where the common road crosses the rail-road, every alternate sleeper was indented on the left side of both rails by the wheels, and

these indentations were at the same distance asunder as the flanches of the wheels were when in order, but those on each succeeding indented sleeper were further from the rails than those on the one preceding.

These facts indicate that the engine had oscillated laterally, and very likely vertically also, as this class of engines are liable to do, until it got off the rails, and that then its speed caused it to jump to such an extent as to make it pass from the first sleeper to the third, fifth, seventh, and so on, proceeding at each jump a distance of six feet; until at last the crank axle was fractured, and both ends of the front axle were broken off.

Much pains have been taken to make it appear that the breaking of the axle led to the accident, but from the foregoing statement, it is apparent that the breaking of the axles was a consequence of the engine jumping or getting off the rails; and it is surprising that the axles should have borne so much striking against the sleeper as they did before they broke.

Some attempts have been made to cause it to appear that the engine was thrown off the rails, by coming against the entrance to a crossing from one line of rails to the other, but that could not be the cause of the engine being thrown off, as it left the rails one hundred and fifty yards short of the crossing.

It is hardly conceivable that both ends of the front axle could be broken off, at the same time, by any ordinary running, however bad the iron might be; but the jumping from sleeper to sleeper is sufficient to account for the breaking of both axles.

When an accident occurred on the Eastern Counties Railway, the rails were bent for sixty yards. On this line two dreadful accidents have taken place without any other apparent cause than that which is attributable to the peculiar action of four-wheel engines.

Some persons have endeavoured to show that the accident on the Brighton Railway arose from the curvature of the rails at the part, where it occurred, and the bad state of the road from the giving way of the newly-formed embankment, in the face of the facts, that the road is straght, in a deep cutting in the part, and not on an embankment, and was in very good order.

When the accident occurred on the

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