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211 cylinders are closed at their lower extremity H, by valves opening upward,

On turning the handle A, a rapid motion is given to the pinion-shaft and eccentric, which has an inch and a half throw; the connecting-rod d, being attached intermediately to the beam E, a throw of three inches is given to the elevators, which, thus receiving a rapid alternating motion, deliver a stream of water from their nosels I, into the cistera or receptacle, from which it flows in any required direction. The second engraving shows an arrangement for drawing water by means of this apparatus, from wells of a greater depth than could be advantageously accomplished by a single lift. E is the working beam to which two elevators are attached, the first, 99, raising water from the reservoir R, into R', the former being supplied by the second elevator g'g', from the well W.

The pinion-shaft is in some cases fitted with two, three, or more eccentrics, which give motion to a corresponding number of elevators contained within the same frame, so as greatly to increase the power of the engine, without adding much to its bulk. It will be apparent

that as the one elevator, with its contained I

column of water, is exactly counterbalanced by the other, the machine is constantly in a state of perfect dynamic equilibrium, and therefore the motion

communicated to the machinery, and g!

thence to the fluid, produces a direct action, raising the largest quantity of water with the smallest possible expenditure of power.

What the capabilities of this engine may eventually prove to be, remains to be ascertained; in the machines already completed, the quantity of water raised far exceeded the performances of any description of pump hitherto employed; but as none of the machines were sufficiently large to employ the whole power of a man, mechanically considered, no data have yet been obtained upon which to found any calculations.

As the matter progresses, however I shall have much pleasure in communicating the results, and remain, Sir, Yours respectfully,


HYDRO-PNEUMATIC BUFFERS. Sir,- In the February Part of the was executed, and put to work by me, as Mechanics' Magazine, which has just already stated, without improvement or reached me, I find two articles having suggestion on the part of Mr. Dawson or reference to my Hydro-pneumatic Buf any one else; and the actual cost was fers, described in the No. 956, for De- nearly double that guaranteed and paid cember last, the first signed "N. N. L.," by that gentleman. the second, “E. Heydn," whom I pre I am, hence, not indebted to Mr. Dawsume to be the person who has been for son, Mr. Heydn, or any other individual, some time shop-foreman in the carriage either for the distinguishing principle, or department of the Dublin and Kingston for any one of the details of this sort of Railway Company's repairing establish- buffer, which I am therefore justified in ment. I dislike, extremely, what is calling my hydro-pneumatic buffer ; and usually termed controversy, which seldom the full right and title of inventorship to has truth for its object; and should not which I thus formally reclaim. now ask a place in your pages for a few What claim Mr. Heydn may sustain remarks upon these communications, did, to having been the proposer of the plan not the latter contain averments and in meditated by Mr. Dawson I do not know; sinuations of plagiarism on my part,

but I have no recollection of Mr. D.'s ever which are as untrue as they are ungrace mentioning his name to me in connexion fully put forward, and which I beg per with it, (although I believe he was then mission, in the first instance, to refute. employed by him in some capacity :) but

Some time in December, 1835, or Ja- granting Mr. H. the full credit of il-adnuary, 1836, a Mr. Dawson, a highly; mitting that, in 1835, he “proposed to intelligent coach-maker of this city, called have a piston to compress air at atmoupon me to enquire the cost of a cast-iron spheric pressure in a cylinder, as a simple cylinder with open ends, bored true, substitute for railway coach-buffers"about 4 feet long, and 4 or 5 inches dia then he simply proposed to do what a meter, which he stated he wanted for an score of others had tried to do, and failed, experimental purpose.

I had known before he was born. Mr. Dawson as a railway carriage builder Air springs in this form were proposed previously, and almost my immediate in France in the time of Vaucanson ; reply to him was, “that I could guess they were proposed and tried by Edg. what the experiment was—that he in worth on wheel-carriages—were patenttended it for an air-buffer ;” and I then ed, as applied to draft and to harness, at once told him that I had previously twenty years, or more, ago—were progiven the subject some attention that posed to be used to ease the draft on the air-springs for various purposes of draft, track-lines of canal boats by, I believe, &c., had been long ago proposed—that Sir John Robison-are mentioned by they never had been made to answer, in Dr. Gregory—and had been talked of as consequence of the impracticability of applicable to buffing, by me, to various making a piston or stuffing box air-tight engineers, long prior to 1835, to whom I -and that I considered the only road to found the idea was by no means new, but success was, to confine the air by a liquid, who all concurred with me, that the imsuch as water. I further, on the moment, practicability of confining the air was a sketched the general plan for ihe hydro- fatal objection. So much for the origine pneumatic buffer, such as it was after- ality, even of the crude and imperfect wards executed.

notion ; but now let us for a moment Mr. Dawson had asked the cost merely consider the “decided improvement,” of a bored cylinder: he now admitted it the plan of plans, which in the year 1842 was for an air-buffer, and that his plan Mr. H. brings forward to supersede mine. was simply a piston on the middle of a To avoid prolixity, the reader must refer rod passing through stuffing-boxes in the to his figure, (page 139.) He proposes otherwise close ends of the cylinder. a cylinder having a solid packed piston,

Having made proper drawings of my with a rod passing through a stuffing-box scheme, I showed them to Mr. Dawson, in the cylinder cover at either end, a who agreed to make the experiment on valve opening inwards in the middle of iny plan, I guaranteeing the cost not to the length, and a safety-valve outwards. exceed a certain sum. The apparatus Now, I omit all consideration of the pro


213 portions of this affair, or of its details. I single empty carriage, violently started, confine myself to a single point; and I and as violently stopped; but I on two affirm that, before a buffer of this sort or three occasions travelled in it as part were at work one week, both pistons of a train, and could perceive no differwould be found as near as they could get ence in the buffing from the other cartogether, about the middle of the cylin- riages. der; and why? Neither the pistons nor There is no doubt the friction of the the stuffing-boxes can be made air-tight; cupped leather piston was too great, and and hence, although the blow may be hence, that the piston would commonly but momentary, (which is not admitted, remain, perhaps, at three or four inches however,) yet at every blow a small to one or the other side of the middle of quantity of air would make its way out the cylinder ; but this is perfectly unimof the middle portion of the cylinder, portant. pass the piston, and get between it and The air-vessels were under the seats, the cylinder cover, and there being no and not inconvenient: the weight of the thing to remove this again, and its quan whole apparatus, full, was only about tity being continually increased at every 9} cwt.; and hence, any objection on blow, the two pistons would soon get this score is preposterous, especially on a most lovingly together in the middle. line where some of their first class carBut assume this not to be the case-as riages have six wheels, and six or more sume, as Mr. H. does, that his pistons huge springs, and solid 21-inch round are absolutely air-tight-then, what is iron buffer-rods; while this affair was in the use of his valve opening inwards ? one of the worst and oldest of their light for, as no air can escape from the cylin- third-class carriages, which, if still in exder, but by passing the said air-tight istence, must be a truly venerable article, pistons, and the cylinder is already full, but probably is so only in the sense in no more can be drawn into it, after ap which a gun remains the same which has proach and on separation of the pistons, had a new lock, stock, and barrel; or in and so the valve is useless, unless as an which it is said, the king never dies. It adjunct to the preposterous safety-valve, is quite likely the stuffing-boxes often We have therefore a very pretty speci- leaked water for want of attention ; but men of reasoning in a circle. What the if they did, how much more would Mr. learned writer means by the "rarefied air H.'s stuffing-boxes leak air ? in the centre," on "the approximation I need not, however, pursue his reof the pistons," is hard to say, unless, marks on this part of the subject farther: being an Hibernian, he mean

their ill-nature is as transparent as their densed,” when he says “rarefied :" this irrelevancy to the principle in question, is the more probable, as he ingeniously which is, the rendering an elastic fluid says-his pistons, when relieved from a confinable as a spring by means of a blow, "collapse"—that is, they collapse liquid; and not whether the details of away from one another!

the method by which this was first atBut enough of Mr. H.'s invention.

tempted were perfect or not. I must Now, as to his observations on my buffer add, however, that Mr. H.'s observation, in usc upon the Dublin and Kingston that its being on the Kingston line, in Railway, it might be enough for me to the midst of a different system, was only repeat, that I lost sight of it and the sub so in form, and not in system, &c., is ject; and that, had I not thought the founding a sophism upon a wilful misoriginal construction needed improve. construction of my words. True, it was, ment, I would not have designed those as I stated, a "thorough buffer,” but subsequently proposed by me. The first different in structure and management time I ever tried it along the line was from every other buffer on the line; with one carriage alone, after an en and, I will add, capable of bearing shocks gine, in which there was no one but Mr. that none of them could stand. Bergin, of the Dublin and Kingston The succeeding observations about my Railway, and myself. On suddenly stop proposed upper, or top buffer, are scarcely ping and starting, the check was no worth criticism. Either I have been doubt hard; but not more so than with very obscure-or this writer is su obMr. Bergin's own buffers under similar tuse, as to have wholly mistaken the very circumstances, viz., the traction of a ground of my proposal. I am so fully

o con

convinced, that a “coach body” will “ N. L.,” whose gentlemanly style is in withstand no shock, that the very aim of pleasant contrast with that of the paper my plan is to provide something in its just considered. There is a great deal place that will, and place it so as to of ingenuity in the plan proposed by receive the shock. The lever of the this gentleman, for buffing the recoil of “first order," is very learned, though the buffer, by bringing it up against a somewhat out of date as mechanics now second body of air; but it is a provision stand; but, unfortunately, it should be, against an evil that does not exist in “a lever of the second order," as here practice. No such thing actually occurs, talked of. Neither is there any mistake (even in a large model,) as the plunger about the place of the centre of gravity being driven out against the fillet of the of a loaded railway carriage, as, if neces cylinder with a sudden shock-or consary, I shall take occasion to prove, with cussion and for two reasons.

In the permission, in your pages.

Mr. H. first place, in the case of collision of leaves out, “loaded :" perhaps this seems two such buffers (say in train), the to him unimportant! Mr. H. can state driven-in plunger cannot return outfrom much experience, “that in nine wards faster than the opposing buffer cases out of ten, whatever be the nature or plunger, permits it by resilience of a collision to a railway train, the from it; but as both buffers are imcoaches are never totally upset” Did perfectly elastic bodies, this velocity canMr. H. ever see a collision, or the results not be as great as that with which the of one, beyond the precincts of the Dub- plungers were driven. Further, the relin and Kingston Railway ? Never. How silience of the buffer impinged upon, many collisions have there been upon it? has a tendency to move uniformly, while Two, or three at most. This is the the return stroke, or motion outwards of “much experience" from which he the impinging buffer, has a tendency to makes an induction of nine cases out of accelerated motion. Lastly, the friction ten; and it may be questioned, did he of the stuffing-box gland is at all times ever witness these two or three collisions ? enough to prevent any perceptible blow I did not. Yet, I am credibly informed, on the fillets, although unaided by the that in one of them, some of the car. two former causes of retardation. The riages were thrown right over the others, fillets, I should have stated, also have -and why? Because the buffers were a collar of leather between them, against below the centre of gravity, and there which they mutually abut. was no resistance to motion above that But supposing that these were real conpoint. A capsizing, or throwing off the ditions to be provided for, I much fearrails, has attended every known collision. indeed I feel authorized to affirm-that Mr. H. does not know, but other peo the method proposed would not meet ple do, that what is called “ statical the difficulty. First, because the centre couple,” cannot be equilibrated by any diaphragm, or piston, could not be kept one force, or by any number of forces, tight, being nearly inaccessible, and be. applied at one point, or in a line at right cause the glands could not be even made angles to the arm of the couple. Yet, tight from the practical difficulty of adthis is what is attempted to be done by justing three perfectly coincident bearthe present arrangement of buffers of ings on an absolutely rigid bar, such as whatever system.

the plunger is: the greatest practical difAll that is said about the necessity of ficulties also would attend the equation the top buffer on my plan being of equal of the glands, and their necessary pack. size and strength with the lower ones, ing and fillets in connection with such only shows the writer's imperfect com cylinder, the bore of which, and hence prehension of the subject, as must be evi the diameter of the piston, being larger dent to every competent judge, i. e., to than that of the end glands inside the every mechanic who unites theory to fillets. practice:

All the moving parts requiring atten. I regret to have occupied your pages tion, &c., would be doubled in number, at such length, with matter comparatively and more than doubled in liability to uninstructive to read, and disagree derangement, and it would be very difable to me to be obliged to write--and ficult to attach the outer cylinder to the willingly turn to your correspondent under carriage in a substantial manner,




and leave it free at both ends. These

own eyes, and judge by the light of their are all mere practical objections in detail, own common sense—most of the absurdiwhich, however, seem to me conclusive, ties of the present day would long since as to the inapplicability of the contrivance, have passed into oblivion. Having howeven if it were necessary, which it is not. ever no other guide but the dicta of in The plan is, nevertheless, ingenious, and ventors, and seeing how utterly we are perfectly correct in principle.

without the means of detecting the Oil, in place of being a better fluid chemical or practical errors on which for these buffers than water, is about inventions are frequently based; the the worst possible; it is nearly as hard to boldest assertor too often obtains the confine as the air itself, and will break

most encouragement, while he is himself, out of joints which are perfectly water perhaps, deceived by occasional success, tight; nor has it any advantage in lubri the result of causes over which he had cating the parts: the packing of the no control, or of which, perhaps, he had glands is steeped in tallow and palm oil, no conception. which always preserve a greasy coat on Under these circumstances, many the plunger, which the water, of course, plans which proceed on wholly erroneous does not remove.

principles, continue to be pressed on the Wherever the climate is such as to unsuspecting public, while others, posendanger the freezing of the water in

sessing real merit, are rejected, from the the buffers, the

brine is the proper want of suitable means for estimating fluid, i. e., a saturated solution of com their qualifications. In the absence of mon salt, which requires a very low tem internal inspection and observation, no perature to freeze, and has no cor plan should be sanctioned as efficient, rosive action on iron whatever, because

or rejected as unsound; seeing how the it contains no combined air, as I have supposed merit of the one may be deshown in another place. All oils get pendent on unascertained, unsuspectthick and viscous at moderately low tem ed, or partial causes, while the supperatures, say 35° Fahr.

posed defect of the other, may be the In conclusion, while I am conscious of

result of accident, omission, or local cirhaving bestowed some care and thought cumstances all of which, however, upon the subject of these buffers, and

would have been instantly detected had therefore have not advanced crudities suitable means of inspection been affordcapable of immediate or obvious amelio ed. Of these, I will hereafter give some ration, still I am equally conscious that illustrations. no new method was ever made perfect At present, we have no test of the but by repeated trials, practice, and emen working of any “smoke-burning" expedations. The principle I have submitted dient, but the appearance or disappearance to the public, together with the best

of the black cloud at the top of the chimmodes I at present know of carrying it

ney; yet this absence of visible smoke, out; and no one will be better pleased to

may really be the result of injudicious see them improved, than, Sir, your obe and even wasteful expedients, or the dient servant,

passing off of the combustible matter in ROBERT MALLET.

an invisible, rather than a visible form. For as to drawing any correct inferences from occasional results, while we are yet

unable to ascertain or determine the AXD BOILERS. BY C. W. WILLIAMS, causes which produce them, it is but a ESQ.

species of self-deception, in which we S1R,-In my last communication, I al would most likely be setting down to prinluded to the absolute necessity for inter- ciple, what, if we had the means of judgnal inspection before any correct estimate ing correctly, would be found attributable can be formed of the value or effect of to merely local or accidental causes. any • smoke-burning" or smoke-preven. Thus, we are often unconsciously the tive invention, or the extent to which means of perpetuating error and fallacy; combustion may take place in any fur and hence, also, the discrepancy between Dace. Had the owners of boilers and the results attributed, by different ex furnaces been hitherto enabled to make perimenters, to one and the same plan their own observations—to see with their or process.






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