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78 THE CIVIL ENGINEER AND ARCHITECT’S JOURNAL. [March 1,1S6S. force is thrown on a spring by momentum to flatten it beyond, its normal condition, that extra force passes to the rail—not, however, as the blow of a hammer, as in that case the line of motion of the centre of gravity would be represented as in Fig. 6, but as a load graduated from its normal condition according to Fig. 6. Showing the line that would be traversed by the centre of gravity to each side of the centre line of motion if there were no springs, each angle representing the blow of a hammer on the rails. thejvelocity of the wheels and the time taken up by the springs in their action of deflection and return, better represented, per haps, by a double inclined plane. (See Fig. 7.) Fig. 7. Double-inclined plane, showing how the concussion or blow is given to the rails beyond the normal or fixed load on the wheels ; caused by oscillation. B to A is a plane representing the deflection or downward action of the spring. A to C is a plane representing the return of the spring to its normal position. A to D represents the greatest deflection of spring, usually amounting to from 30 to 75 per cent, beyond the normal load of six tons on the wheel. B to C distance traversed on periphery of wheel during time taken up by the spring in its action of deflexion and return to its normal position. The best practical illustration I can offer to the meeting upon all these points of mechanical engineering is to invite attention to the models and drawings before it of an engine which has been specially designed to meet the objections we have just been discussing. The engine does not exist as a mere abstract idea, but is daily in operation on the Neath and Brecon Bailway; and within the last few days one of them which has been work ing over two years, has undergone a severe test in the presence of several eminent engineers, who, in consequence have accorded it their warmest approval, several of whom I have the pleasure to see here this evening, and who may probably be disposed to describe their own experience. The engines are remarkable for the almost total absence of oscillation, and the graceful ease with which they run round the very sharpest curves is matter of surprise to all who have ridden on them, the sense of safety experienced when on the engine is irresistible, and the motion is so pleasantly unlike that of the ordinary engines, that it has been described by Cap tain Tyler, of the Board of Trade, as giving the sensation of flying, and by others as that of sailing in smooth water. In corroboration of this it may not be considered out of place here to quote a passage from the report of Captain Tyler and Mr. Eboral, who have lately returned from an inspection of the Grand Trunk Railway of Canada. In page 44, after giving a full description of the locomotive engines in use on that line, the report says, “ The class of engine best suited to the climate, and for the various circumstances of the case, would I have no doubt, be an engine running on two bogie trucks, each provided with a pair of cylinders, and four-wheeled or six-wheeled, ac cording to the work required—and without a tender. Such an engine would be peculiarly safe to travel over a winter road; would combine a minimum wear and tear to itself and the rails, with a maximum of adhesion, and would be the most effective and most economical that the company could employ. I had the opportunity some time ago of testing engines of this descrip tion on the Neath and Brecon Radway, designed by Mr. Fairlie, and have found the principle to be good, though certain points of detail required improvement. Such engines are also in use for the sharp curves and steep gradients of the Queensland Railway.” These engines have developed a relative power equal to two of the engines employed for hauling the goods trains on the Lon don and North-Western Railway, whilst the destructive effect on the rails, road, and engine is greatly reduced. The employ ment of such engines would enable companies to double the carrying capacity of their lines without necessitating any addi tional outlay, and therefore they are especiaUy valuable in the case of single lines. There are those who might consider it inexpedient to increase the present dimensions of goods trains, and in that case the engines would be too powerful, but the point is met by their permitting a very large reduction to be made in the weight per wheel amounting to so much as one- half that on the ordinary engine wheels, while its power re mains equal to the best of them. It will therefore be readily understood that the life of the wheel tyres and rails would be greatly prolonged. Companies like the London and North- Western, having reached, it is supposed, the maximum of load per train, have been driven to the costly expedient of tripli cating their lines of rails for great distances. I venture to think that this immense outlay could have been avoided by the use of engines better adapted to the exigencies of an over crowded traffic, whilst at the same time assuring a saving in haulage labour of nearly one-half, together with a most appre ciable saving in fuel. I have spoken of the Metropolitan Railway and its enormous traffic. That is but a portion of the prodigious traffic of the metropolis and its suburbs. This description of traffic should be treated in altogether a different manner to the,main provin cial lines. The Metropolitan should be conducted by stock giving the minimum of dead weight with the maximum of efficiency ; this, I think, could be best done by what may be termed steam omnibuses, made to carry say 60 passengers, but with power sufficient to haul additional carriagesduringthebusiest hours of the day—in the middle or slack time the omnibuses alone could carry the mean average of passengers. The weight of the entire machine, together with its load of passengers, would be less than that of the present locomotive engine alone. I have brought here to-night the drawing of a steam carriage, designed expressly for conducting the traffic of the proposed cheap lines in Ireland, which will be useful to show you the character of steam omnibuses (to be modified to suit circumstances) I should recommend for working metropolitan lines. This carriage would work with efficiency and economy the line over Mont Cenis. (See fig. 8.) Fig. 8. Fairlie’s Locomotive Steam Carriage for working cheap mountain or agricultural lines.