THE MONO RAILWAY. THE GYROSCOPE AT WORK A NEW DEPARTURE.

Progress, Volume II, Issue 8, 1 June 1907, Page 286

THE MONO RAILWAY. THE GYROSCOPE AT WORK A NEW DEPARTURE.

The gyroscope has been a child's toy tor generations, the favourite form being the top. In like manner the conic sections were mathematical toys which have amused the

learned and after 25 centuries found a most important application to science ; inter alia revolutionising astronomy. It will be a curious and welcome coincidence if the gyroscope were to after all end by obtaining a useful career. The chances are at present much in favour of that consummation. The principle has now engaged in a marked degree the attention ot inventors and practical men. The other day a German inventor conceived the idea of using it in ship building, and applied it to a small craft, which went through a heav} T sea without rolling Now Brennan ot torpedo fame is said to be applying the principle to his scheme for a mono-railway. Some 3-ears ago this famous inventor was in the service of Mason and Firth the well known prmteis of Melbourne. Being a man of ingenious mind, and persistent

withal, he turned his attention to engineering questions, attending to them in his spare time. In due course he evolved his method of steering torpedoes by wire, and though he was much ridiculed by the thoughtless of his city, he knocked so many targets to pieces that he attracted the attention of the British Government, which secured his invention by a cash payment of £100,000, and his services b}^ a salary of £1,000 a year, a commission in the Royal Engineers, and permanent employment in a high post at Woolwich Arsenal. That was the origin of the Brennan torpedo. Since then, neither the good fortune, nor the work have been able to blunt the keenness of Captain Brennans invention. Thus we now hear of him explaining the principle of his mono-railway to a gathering of engineers and other experts all of whom pronounce the same to be perfectly feasible. " Gyroscope " is a name applied to various instruments designed to illustrate the phenomena of rotation. They all consist essentially of a disc revolving on pivots within a ring. In figure a the ring is supported at one end of its axis by a string. Take hold of the outer end of the axis of the disc, rotate the disc by means of a string, let go the outer end the disc will remain at the angle at which it is left. It will do more : it will spin round the supporting string maintaining equilibrium during the whole of the time of the spinning. If, as shown in b, a weight is attached to the framework at one end of the axis, the whole rotates about the vertical. The reason why the rotating body in a does not fall is that in such a body gravity is no longer allowed to act singly, but must in every instant enter into composition with another force. Hence the body in such case can not simply fall, but must move towards such new place in space as the combined actions shall determine : and hence again, the same force which ordinarily produces a vertical fall, here carries a body round a horizontal circle, or secondarily sometimes even causes it to ascend. Now the whole downward action of gravity on the disc is very slight compared with that of the rotation first imparted, sometimes as small as the ratio of Ito4o or 60. Clearly the rotation is vastly the predominating force. Now in a railwa}^ upon the mono-railway system the cars are suspended beneath a single rail, or supported upon a rail which runs through the body of the car. In either case, the car hangs like a pendant, and to a large extent, its stability depends upon the equal balance of the load. Obviously, this balancing is a difficult problem to face, when passengers are constantly entering and leaving the vehicle. To guard against accidents, which might take place through the swaying, side rails have been used with which idle pulleys carried by the car come in contact when the oscillation is greater than usual. We have no details of Brennans adaptation of the gyroscope to the overcoming of this difficulty ; but it may be assumed that he employs a large flywheel which is caused to revolve at a high velocity. Probably the revolution is in a vertical plane, and its tendency is upon the explanation of the theory above given, to maintain the equilibrium of the car in spite of any inequality of the loading. We hope in a future issue to give full details of this very interesting invention.

M. Alfred Leblanc has just made a balloon voyage from Pans to the shores of the Baltic — a distance of 630 miles — in fourteen hours