BERGIN'S PATENT RAILWAY BUFFING APPARATUS. We have more than once had occasion to mention the ingenious buffing-apparatus which Mr. Bergin, the intelligent Secretary of the Dublin and Kingstown Railway, has applied to the carriages under his superintendence, and the good effects which have resulted from its adoption. Our attention is again drawn to the merits of the invention by the Third Annual Report of the Board of Public Works in Ireland, now before us, in which we find it spoken of in the following favourable terms: "Thomas F. Bergin, Esq., Secretary to the Company, has applied to the carriages a spring-bar (for which he has obtained a patent), admirably adapted to ease the shock of sudden stopping or putting in motion, while, at the same time, it is more strong, more simple, and much more economical, and attended with other great advantages over the system hitherto adopted." A description of the apparatus, furnished by Mr. Bergin, and illustrated by engravings, is annexed to the Commissioners' Report. We shall now transfer the former, with but little abridgment, to our pages; and so much, also, of the latter as is necessary to a clear understanding of the construction of the apparatus. Mr. Bergin's Description. Immediately after commencing the traffic on the Liverpool and Manchester Railway (the first on which long trains of carriages were moved by locomotive-engines at high velocities), it was found that every time a train was put in motion or stopped, violent concussions took place between the several carriages, equally disagreeable to the passengers and destructive to the carriages them. selves. These concussions arose from the following cause; viz. by reason of the inertia of all heavy bodies, the same engine-power which would be adequate to draw a given load along a railway at any required speed, would not be sufficient to start the same load from a state of rest; it was therefore necessary to connect the several carriages by chains of some considerable length, say three or four feet, by which arrangement the inertia of the train was as it were divided into as many parts as there were carriages, and these several parts being each within the power of the engine, were overcome in succession; but as the first carriage would have attained a certain amount of velocity when the connecting chain came to pull the second, this second must of course be at once dragged from rest into motion at a speed nearly equal to that already acquired by the first, and so on through the entire train. Now a very slight knowledge of the principles of mechanics teaches that the concussions already mentioned were the necessary result of the action described; the same principle (inertia) produced the same effects at stopping a train, and also at every change in the relative velocities of the individual carriages when in motion; and as the force of these shocks was dependent on the velocities, the greater the speed of travelling the more violent they be came. The obvious remedy for the evil complained of was to provide a means by which the full amount of motion acquired by any part of the train should be gradually, not instantaneously, communicated to the other parts; the elasticity of a spring was a suitable means, and an apparatus was accordingly added to the Liverpool and Manchester passenger coaches, a sketch of which is annexed, and which has been termed a buffing-apparatus. [Here follows a description of this apparatus]: This apparatus is complex, and consequently expensive; it also requires to be very strong, as on a little consideration it will be evident that the spring-bars, levers, and frame of the first carriage have to bear the resistance of the entire train; a very rigid spring is therefore necessary, the range of action of which is, of course, very limited (in practice not exceeding a few inches), consequently the concussions, although much diminished, are still very considerable. The apparatus being attached to the carriageframe, which is, of course, supported on bearing springs, it rises and falls according to the load; whence it constantly occurs, from the carriages being unequally weighted, that the buffer-heads, opposed to each other, and which by right should be at the same level, vary by nearly their own diameter. Whence, in the event of a violent blow, the bars to which they are fastened are almost certain either to be bent so as not to play in their sockets, whereby the whole apparatus becomes inoperative; or else to be broken off (such we have found to be the case in every instance when an unusually severe blow took place). After the apparatus described was added to the Liverpool and Manchester carriages, it was found that the train no longer proceeded with a steady motion in the direction of the rails, but that each carriage had acquired a very considerable lateral motion, by which the flanges of the wheels were constantly striking or rubbing against the rails, so as to cause a considerably increased resistance from side friction; indeed, on looking along a train of six or eight carriages, the serpentine motion is very striking. The cause of this unsteady motion will be evident when we recollect that the point from which each carriage is drawn is in one direction, the centre, and in the other the after extremity. These considerations, the result of numerous careful examinations of the carriages on the Liverpool and Manchester Railway previous to ordering our own, led me to seek for a remedy; as on the Dublin and Kingstown Railway, so very large a proportion of the traffic of which would be passengers, the extent of which it would be difficult to anticipate, but which must of necessity be immense, it became a matter of paramount importance to attain, as far as practicable, the most perfect comfort and security, and also to reduce as much as possible the wear and tear of the numerous carriages which the company must provide. The apparatus which I designed, and which has been successfully applied to thirty-five of our carriages, is represented in plan, section, and elevation in the accompanying drawings. A slight frame of sheet-iron, AAA, consisting of two similar plates, three inches apart, each about thick, secured together by rivets, rests on turned bearings on the centres of the axles; a single bar, BB (I have used a welded iron tube of inches thick and three inches diameter, as being the stiffest), the entire length of the carriage, and extending about two feet beyond each end, passing through an oblong hole three inches wide and nine inches long (H, 4), is supported on this frame by rollers, CCC, allowing it to be moved lengthways with great facility; on this tube or bar B B B is placed at either end (within the framing of the carriage) about four feet of spiral springs, DDD, of graduated strengths; one end of each of these sets of springs rests against a strong collar or boss, E, fixed to the bar or tube, and the other end against a small box of iron, F, attached to the frame A, and furnished with one of the rollers C previously mentioned, also with the two friction rollers G and G projecting a little beyond its surface, and resting against the inner side of the carriage-frame end. To each extremity of the tube B B is attached a buffer head, I, by means of a bar of iron, K, passing through B B, and furnished with a nut and screw at each end; immediately within the buffer-head, and resting against it, is a bar of iron, We have given the section and plan only (our figs. 1 and 2), and have omitted the after-part of the carriage-frame in each, as it is an exact counterpart in every particular of the front part. We have also, for convenience sake, given detached views of the buffer-heads, figs. 3 and 4, being a section and plan of that in the front, and figs. 5 and 6, a section and plan of that in the rear.-ED. M. M. L, for attaching the carriages together. It will be observed, that this apparatus lying loosely on the axles, is perfectly independent of the frame-work of the carriage, which is supported in the usual manner on bearing springs, M M, and, in consequence of the oblong holes HH, rises or falls according to the load without affecting the buffingapparatus. The action of the apparatus is as follows:-The train being to be moved in the direction of the upper arrow, the motivepower is applied at L 1, and draws forward the central tube B B, thereby compressing the springs DD between the boss E and the friction roller-box F, which rests against the end of the carriage-frame, without moving this latter until the elastic force of the compressed springs becomes sufficient to overcome the resistance presented by the friction and inertia of the carriage, when the latter begins to move forward so gently as not to be perceptible to persons seated therein; the second and each succeeding carriage in the train is by similar means brought from a state of rest into motion, as (altogether independent of the springs D D) the tube B B acts on B2 merely as a simple connecting chain, rope, or bar, would. In case of a concussion from behind, or of one carriage running against another, it will be at once seen that the resistance is offered by the furthest end, the effect being to drive the tube B B forward, compressing the springs at the remote end; and the carriage will not be affected by the blow until (as in drawing the train) the elasticity communicated to the springs overpowers the inertia of the carriage, which then begins to move, actuated by a force just sufficient to start it; any ordinary velocity might be thus (theoretically) resisted by sufficient length of spring, without any strain or violence to the carriage receiving the blow, but practically the springs are limited to about four feet, allowing a range of action of about two feet, beginning to be compressed by a force equal to about twenty pounds, and presenting a gross resistance to entire compression of upwards of two tons, and which have been found sufficient for all practical purposes. It will be observed, that as the springs of each carriage act totally independent of each other, and of all the carriages in the train, except that to which they are attached. each has but to bear its own share of the resistance, the sum of which is made up of the separate resistances of all the springs acted on: thus, if one set offers a resistance equal to two tons receding through two feet, and that there be ten carriages in the train, the gross resistance to a concussion would be equal to twenty tons through two feet; and if the buffer-heads of each carriage were in contact, this great amount of resistance would be opposed without the carriages being necessarily moved forward, as in the case of any obstruction on the rails, or any of them bearing more than two tons. On the contrary, in the other apparatus, supposing each spring also to resist a force of two tons, and to recede, as is the case in practice, about eight inches, each spring being acted on by all that preceded it, the resistance offered by a train of 10 carriages would be but equal to two towns through 10 times the space each separate spring moved, or 10 x 880 inches, or six feet eight inches; consequently the first and each succeeding carriage would, to enable all the springs to act, be forced through a space equal to the sum of the spaces through which the separate springs act; thus the first carriage of the ten would be forced through eight inches for each of the remaining nine carriages, or in all six feet, and it is easy to conceive the difference of the effect in the two cases. Experiments have been tried on this railway, by placing a single carriage, fitted with the new apparatus, on the rails, and running an engine and tender against it with a velocity of six to seven miles an hour, without producing any injurious effect. I have more than once sat in a carriage so struck, without sustaining any injury or other effect greater than is felt on starting a train of carriages fitted with the old apparatus. Another effect which has been realised by the adoption of this apparatus, is a perfectly steady forward motion in the trains, whereby very much of the side friction of the flanges of the wheels against the rails is avoided; and instead of that undulating lateral motion previously described, all the carriages constituting the train move forward in a steady path, as if they had not the power of motion independent of each other. Carriages are hereby rendered much less liable to go off the rails, and can be pushed before the engine in case of necessity with far greater confidence and less liability to accident; as although the impulse is given to the central bar from behind, yet it is obvious the carriage is acted upon from the front, precisely as it would be if drawn in the same direction. I have frequently, during our experimental trials before opening the railway, propelled one and two carriages in this manner at a velocity of thirty miles per hour with perfect safety. The diminution of side friction necessarily diminishes the power requisite to draw a train: the amount of saving in this respect I have as yet been unable to ascertain experimentally with sufficient accuracy to state in this place; I have, however, ascertained that it is very considerable. One other object, of no trifling importance to a concern like the Dublin and Kingstown Railway, which must have an exceedingly large stock of carriages, is also effected; namely, a diminution of first cost of between 50l. and 601. per carriage. In describing the figures, I omitted to state that as the entire resistance to the action of the springs D Dis on the ends of the carriageframe, the centre of each is armed with a strong plate of iron, about fifteen inches square, through which pass the tension rods NN to the outer angles of the opposite ends of the frame; consequently these rods receive the entire force of the springs. COPYRIGHT OF RAILWAY PLANS GREENWICH RAILWAY. Sir,-Some doubt having arisen respecting the accuracy of my allusion to the Lancet case, I applied to Mr. Wakley the Editor, and was informed that an injunction had been obtained against his publishing Abernethy's lectures, but from some circumstances in Mr. A.'s professional situation, it was afterwards dissolved. My prior information I had from a law treatise printed in 1828, three years after the injunction, giving the injunction, but not the dissolving of it. In your remarks, p. 503, you say you incline to think "Mr. Herapath has greatly overrated the profits of the Greenwich Railway." As this may be construed into an imputation on my veracity, I shall thank you to show me in what. If the documents I consulted are to be depended on, and the circumstances contemplated take effect, I am quite satisfied I have underrated the profits. Your obedient servant, Kensington, Sept. 29, 1835. [Nothing was further from our intention than to offer the slightest impeachment of our respectable correspondent's veracity; and we can hardly imagine any one would be so foolish as to draw such an inference from the language we employed. To" overrate" is certainly not to falsify nor even to misrepresent, both of which imply de sign; we understand it to mean simply to miscalculate, and we so used it. Mr. H. invites us to show "in what" he has "overrated" the profits to be derived from the Greenwich Railway; but as we see no utility in retracing the ground already gone over by H., we shall merely, by way of illustrating the sense in which we made use of the term, refer to the item of rent to be derived from the arches. Mr. Herapath overlooking (as we apprehend) that each arch will furnish but the end walls to a house, takes credit for as much rent as if it would form at once a complete dwelling place, fit and ready for occupation. Here, surely, there is great overratingoverrating to the extent of all the capital requisite for the conversion of the arches into tenantable messuages. One word as to the case of Mr. Aber nethy and the Lancet. Mr. A., if our recollection serves us rightly, was not foiled, because of any doubt as to the right of property in lectures, but because, from his habit of lecturing extemporarily, it was impossible for him to verify the copy of which he claimed the right.-ED. M. M.] THE GREENWICH RAILWAY. Sir, I cannot refrain from requesting a place in your Journal for a few observations on the article, "The Greenwich Railway," which appeared in the Mechanics' Magazine of the 26th inst. So mutatis mutandis, commences an extremely unique and good-humoured attack on Mr. Herapath by your correspondent H.; and so humbly thanking him for the exordium, do I commence a reply to this" honest of purpose" and "heavy of hand" gentleman, as you call him. Pray, sir, do not imagine I am one of those scientific knights' errant, who are ever ready to shed their blood, alias their ink, in every wrong fray, and, Don Quixote like, to come to blows with every gander that may be found hissing on the wide common of science, though in the present instance it may appear so. No, Mr. Editor, I am a plain, humble individual, whose courage this time has been screwed up solely by motives of pity for Mr. Herapath, fearing he will not attempt to stem the torrent of unanswerable argument, wisdom, candour, and truth, the "heavy of |