142 THE ATMOSPHERIC RAILWAY SYSTEM. in the opinion already expressed, that any discussion on points which were soon to be submitted to the test of experience, was of comparatively small value. One important service, however, had been already rendered by the discussion, in having elicited the statements of two eminent engineers, who were then engaged in carrying out the practical application of the atmospheric principle on a large scale. They had stated, that all those difficulties, which had been mentioned in the paper, had been foreseen by them, and had been conquered. This fact was important, for it was most desirable that any opposition to the atmospheric system should be based on right grounds, and not upon mere prejudice. The paper had pointed out, with much ingenuity, the minor practical difficulties in the way of the execution and the use of the atmospheric railway; but these he did not at all regard as objections to the system, but merely as the statement of problems, of which the ingenuity of the promoters, in constructing the works, had to invent the solution. Now he thought it only fair to say, that seeing the atmospheric system in the hands of such mechanics as Mr. Cubitt and Mr. Brunel, he had no hesitation in expressing his conviction, that they must have seen their way clearly to sound practical solutions, for all their mechanical difficulties, or they never would have risked their reputation on the construction of such lines. Although he was himself much inferior to them as a mechanic, he could see his way clearly to the solution of many of the difficulties stated in the ingenious paper of Mr. Barlow, and he had such faith in the powers of invention of the engineers of this country, and in the mechanical skill and powers of execution of the workmen, that he had no doubt if the atmospheric system was sound at heart, and in its principle, all these minor evils would disappear. On the faith, therefore, of the talent of these engineers, he would give the system credit for all that their skill could devise, and he had no doubt that they would overcome the mechanical difficulties of practical execution. But there remained the great question of the value of the system as a general system of traction, applicable on all railways, and capable of superseding the locomotive engine. It was on this general ground that the question must be decided, and here the result, he thought, was perfectly clear. The atmospheric system was merely one among many modifications of sta tionary power. As such, while it possessed the advantages, it must encounter, all the evils of the stationary system, and on this broad ground, that the stationary system was neither so economical, nor so con venient, as the locomotive system, he rejected the proposition of the inventors, who wished to substitute stationary atmospheric for locomotive engine power, generally, on railroads. But in justice to the system, and to those who had adopted it, he ought to say, that he had no doubt, that in cases where stationary power was desirable, there were circumstances which might render the atmospheric system peculiarly appropriate. Selecting, for instance, a line where there were many or sharp curves, or many inclines of variable and steep gradients, and where also the trains were numerous, uniform in magnitude and number; such a case was most favourable to stationary power, and to the atmospheric system especially. He thought it would have been wiser if the inventors of the system had brought it forward as an expedient of this kind, suited to these circumstances, rather than as a revolutionary system, proposing to displace locomotives on all the great railways of the country. In that case, they would have received the support of many, who now could not accord with their views. In that modified application he would be happy to see it successful, and he thought the wiser promoters of the system were of his opinion, for it was in peculiar circumstances, of the nature he had indicated, that they were about to introduce it. He should be glad to learn from those engineers who were about to introduce the system, whether they would assure him, that in the application of the system there was no loss incurred in the use of the air as the means of applying the power. He conceived there must be a mechanical loss of power, in the process of first rarifying the air, and afterwards condensing it. Mr. PIм said, that it was not for him to enter into an analysis of the theory of the atmospheric system, but his belief in its correctness was in a great degree confirmed by the investigation of Dr. Robinson of Armagh, who had arrived at diametrically opposite results from Mr. Russell. He could, however, judge of the practical results; and when comparing the actual speed and cost of propulsion on the Dublin and Kingston railway, with that of the Kingston and Dalkey line, the result was decidedly in favour of the latter; on the former, with locomotive engines, & mile with a rise of 13 feet, was traversed in 4 minutes; while on the latter, with the atmospheric system, 1 mile with a rise of 711⁄2 feet and several sharp curves, was passed over in a little more than 3 minutes: the consumption of steam in the Dalkey engine was, at the same time, much less than in a locomotive. Mr. CUBITT, V.P., thought that it was not incumbent on the advocates of the system to show, that it was perfect as a mechanical power. It sufficed to show, that it was superior to fixed engines and ropes, which had been attempted to be substituted for locomotives, not only on account of their cost of steam and fuel whilst travelling, but also because of their excessive tear and wear. If, as had been asserted by a great railway authority, the power required to move the engine and tender, equalled that requisite for drawing fifteen passenger carriages, which was more than an average train, it would follow, that it would cost more to move the engine and tender than the average of all the passenger trains. If, therefore, the traffic could be conveyed by the atmospheric system at a less expense, a great point would be gained. Mr. J. SCOTT RUSSELL gathered from what Mr. Pim had said, that it appeared from Dr. Robinson's calculations, that the power expended, and the power usefully ap plied, were theoretically precisely equal. Mr. Russell had not arrived at the same conclusion, and he would desire to ascertain, whether the engineers intending to use the system and who had doubtless examined the subject carefully, agreed with Dr. Robinson's view, or entertained a more modified opinion of it. Mr. J. SAMUDA could not admit Mr. Russell's view of the loss of power. He contended, on the contrary, that the power primarily expended in forming the vacuum, was returned during the passage of the train. When the air-pumps were working at 15 inches of mercury, with a pressure of 41⁄2 lbs. per square inch on the piston of the steam cylinder, a power was attained in the pipe, equal to 7 lbs. per square inch upon the travelling piston. Mr. I. K. BRUNEL contended also, that a loss of power to the extent that had been stated could not be proved, when a certain amount of work was performed with the expenditure of a certain power. He would admit, that some loss might arise from the absorption of heat, during the process of rarefying the air in the main, but he could not concur in the position assumed by Mr. Russell. PROPERTIES OF THE CYLINDRICAL RING. Sir,-The plane sections of a cone and a right cylinder are well known, but perhaps not those of the cylindrical ring, in all their varieties. Now, from any of these plane sections, let it be supposed that there is the least 143 possible deviation. For example, instead of a cone being cut by a plane, to produce any of its well known sections, let the section be in the least, or any degree, cylindrical, either convex or concave with any plane section of the cone. For a particular example, let a cylinder, to half its diameter, cut a cone parallel to its side; and let the straight line in the direction of the length, equally dividing the surface of the embedded portion of the cylinder, be the axis of a parabolic section. Next consider the orthographical projection of the line of intersection of the cylinder and cone; then suppose the line to be traced on the surface of the cylinder; and further, suppose so much of the cylindrical surface to be enveloped on the plane of the parabola. Here are three distinct lines having inferior branches; viz. 1st. The parabola. 2nd. The periphery of the envelope. The distance between the branches of the parabola, if indefinitely extended, becomes immeasurable. The distance between the branches of the envelope, in this case, although always increasing as they are extended, never can exceed half the circumference of the cylinder; and the distance between the branches of the orthographical projection, although, also, continually increasing as they are produced, can never exceed the diameter of the cylinder. These last two lines so much resemble some of the lines produced by a motion, the reciprocals of that by which some of the conchoids are produced, that I hope they may lead to an easy method of determining of what solids many of the other lines of the septenary system, are sections, envelopes, or projections, both of lines with infinite branches, and such as return into themselves. pondents take equal interest in the progressive improvement of our river steamers, I am induced to send you a statement of the performances of a third vessel, which has indubitably eclipsed both of those abovenamed. I refer to the Queen, which was built and fitted with her machinery and paddle-wheels by Messrs. Rennie, in the year 1841. Her power having been found too small to produce the most satisfactory speed, when laden with an average number of passengers, Messrs. Rennie have this year fitted her with a pair of new directaction engines, and the result of the alteration has produced a most marked improvement in her speed. The engines were first tried down the river on Tuesday, the 5th instant, and again on Sunday, the 10th; and on Friday last the vessel was taken to Long Reach, in order to ascertain her speed at the measured mile. The result of four trials up and down gave a mean of 17.761 miles per hour. In the course of these trials, the following vessels of known first-rate speed were competed with, and all beat in the most satisfactory and decisive manner, viz., the Sapphire, Railway, Hern, and Meteor. The latter vessel, although admitted to be the fastest on the river, was beat 3 minutes in a run of 27 minutes. On Saturday last she was put in competition with the Prince of Wales, Margate steamer; when, although the Prince had her foresail and trysail set, the Queen beat her, in a run of 40 minutes, a full mile and three-quarters. Indeed, the speed of the Queen, since she has been fitted with her present machinery, is such as to pronounce her the fastest vessel afloat; and this satisfactory result has been produced without the intervention of patent engines of any kind-simply with a pair of direct action engines, with a short stroke, and short connecting-rod, a description of engine which Mr. Alexander Gordon has laboured hard to convince the world is perfectly useless! I omitted to mention, that on the Queen's trip up from Gravesend, on Saturday last, she lett the Town Pier at 2 o'clock, and at 21 minutes past 3 she was alongside the Brunswick Wharf, Blackwall; doing 20 miles in 81 minutes, against a strong ebb spring tide, and a stiff head wind. I am, Sir, your obedient servant, L. S. NOTES AND NOTICES. New Railway Velocipede.-Mr. R. Jones, of the Scoint Iron Foundry, Carnarvon, has recently constructed a new locomotive, combining the principle of the velocipede with that of a carriage, capable of carrying twelve persons. The machine is in tended to propel a carriage along the Padarn Railway, but is also adapted for traversing the rails alone. The present is an improvement on the velocipedes previously constructed by Mr. Jones, for the quarrymen on the line-they being worked by the feet only, while the labour is now divided equally between the feet and hands-the motion being induced by handles and pedals, and is so facile in its movement, that a child can impel it rapidly to or fro at will. The machine is wholly composed of iron, and weighs about half a ton.Mining Journal. The Hayle Engine Works.-Messrs. Harvey and Co. have nearly executed an order for six fly-wheels for the South Devon railway, measuring 20 feet in diameter, and each wheel weighing near 14 tons. Two of them have been sent to their destination, and the other four are in a great state of forwardness.-Letters from Haarlem announce that the Mammoth engine has been put to work, much to the satisfaction of the proprietors and engineers. An order is expected soon for two engines of the same size, and on a similar construction.-Falmouth Packet. An Atomic Vagary.-The New York Mirror gives the following as the substance of a lecture lately delivered in that city by a certain Professor Bronson: If a drop of human blood be subjected to examination by the oxhydrogen microscope, and magnified some twenty millions of times (only) all the species of animals now existing on the earth, or that have existed during the different stages of creation for millions of years past will there be discovered. In the blood of a healthy person all the animalcules are quiet and peaceable; but in the blood of a diseased person they are furious, raging, and preying upon each other. This he stated in illustration of his position that man contains within himself all the principles of the universe. It was also asserted that if a dead cat be thrown into a pool of stagnant water, and allowed to dissolve there, a drop of water taken from any part of the pool, and examined as above, will show every species of animal of the cat kind that has ever existed on the earth, raging and destroying one another. The bodies of all the lower animals being thus made up of animalcules similar to themselves and the body of man being compounded of all that is below him in the scale of creation!" Growth of Silk at Norwich.-A person named Leeds, a working cooper, living in St. Edmunds, Norwich, has this year about 10,000 silk worms, which have just commenced spinning in a room at the top of his house, without any artificial heat; they have been this year in the most healthy state, he having lost scarcely twenty from the time of hatching. Mr. Leeds has now materials for several splendid silk dresses, one of which is contemplated to send to Her Majesty.-Chelmsford Chronicle. Manufactures in Canada.-The Montreal Herald lately mentioned the receipt of grey domestic cloth from the Chambly Factory, it being the first sample of the results of manufacturing enterprise, as applied to weaving by machinery, in Lower Canada; and since then, another and a similar specimen, in the shape of half a dozen hanks of cotton twist, from the factory lately established at Sherbrooke, in the Eastern Townships, has been shown. The twist is of superior quality, and can be afforded to the purchaser at a lower rate than the same quality imported either from England or the United States. There is no country in North America better adapted for manufactures than Lower Canada, from the extent of her water-power, and the comparative density of her population. INTENDING PATENTEES may be supplied gratis with Instructions, by application (post-paid) to Messrs. Robertson and Cc. LONDON: Printed and Published by James Bounsall, at the Mechanics' Magazine Office, DESCRIPTION OF A TRAIN BUFFER CARRIAGE FOR THE PREVENTION OF ACCIDENTS ON RAILWAYS. BY SIR GEORGE CAYLEY, BART. SIR,-Permit me through your valuable Magazine to call the attention of the public once more to the means of preventing those horrible railway accidents that seem to be accumulating in an accelerated ratio as an accompaniment to the accelerated velocity now adopted. It may be said, perhaps, that as crows only fly at twentyfour miles per hour, men, not born with wings, ought to be contented to rival in speed those so gifted by nature; and that if they will not be so contented, they should not grumble at the consequences. Still it is our duty, looking at things as they are, to render the risk the least possible. In every attempt of this sort we are invariably met by the present construction of all the enormously expensive apparatus belonging to railroads, and the question is narrowed, not into what might be done on new constructions, but what can be done with little additional cost on the present ones. Certainly some general buffer for every train, must sooner or later, either by the voluntary act of the companies or by the compulsory order of the legislature, be adopted. In my former papers* I have proposed a machine of this sort, by having a huge air cylinder and piston placed on wheels; and I still think some modification of that principle, under the advice of our very competent engineers, will be the best way to meet the case. In the mean time, and if we cannot effect the whole, let us try to do a part of the good, by having a series of large cushions or mattresses well packed with some elastic material placed in front of every engine, as represented by A, fig. 1. This may be attached to a hinged tablet or plate, so as to avoid inconvenient length. When on the turning platforms it may be placed in the position B. The little additional weight on the front wheels caused by this buffer will not be of any material consequence, and it would prevent many an injury, though not possibly qualified to meet extreme cases. But in the present state of things, "bis dat qui cito dat." * See Mech. Mag., vol. xxxvi. p. 397. The wish of our esteemed correspondent is likely to be soon gratified. Mr. H. S. Rayner, of Ripley, has recently obtained a patent for a system of railway buffers, which will, we believe, fully meet all the difficulties of the case.-ED. M. M. It seems from experience, that the natural tendency of so great a mass of matter as that of a locomotive engine to preserve the right line of its course is such, that, when opposed by the carcase of a cow, or the fragments of the gate, which it smashes in its impetuous course, it generally falls again within the rails; and to obviate those serious accidents that occur from the engine running off the rails, it would be well to take advantage of this principle. The variation of an inch decides the case, and as it so frequently happens to fall within the rails, it is probable, that when it falls without these bounds, the deviation at first is very trifling. Hence, if the front wheels of the engine were provided with three or more grooves each, capable of running on the rail, though not exactly in conformity with the directions of the tender wheels, they would be yet sufficiently so to hold the engine on the rails till the train stops. See C, fig. 2, which represents a section of the lower portion of such a wheel. The adoption of this plan would not imply any alteration of the general line of rails as at present laid; but at the switches and points there would necessarily be a different arrangement. these places the rails must be made in halves, and solid, as at D, when the part leading to the intended new course must remain at its original level, and the other be depressed below the flanch of the wheel as at E. These actions may readily be so coupled by proper machinery, that the one could not take place without the other. At The necessary alterations in the construction of the points of switches to meet this arrangement, may render it necessary to adopt the double flanch, or groove form, in the front wheels of each carriage; in which case it may be well to give them also the advantage of the three grooves in preference to one only, for it frequently happens in accidents that several carriages in succession become the leaders of the train, by those in advance having broken away, and thus the remainder of the train may be preserved on the rail by these extra grooves. I shall not trouble you or your readers with more on this subject at present; but |