THE MONO-RAIL

New Zealand Times, Volume XXXIII, Issue 7444, 19 May 1911, Page 1

THE MONO-RAIL

BRENNAN’S DISCOVERY INTERESTING LECTURE BY PROFESSOR lABY. Brennan’s mono-rail and. the gyroscope Were dealt ivith.iir a most interesting: manner by Professor Laby in a. lecture at a special l gathering of the Philosophical, Society at Victoria College last night. - Mr Hudson, the president of the society, presided over a large attendance. Professor Baby said that he was- present when Brennan first, exhibited, a model of .his mono-rail car, before the Royal Society in London in May ox 1907. The car was equipped with an automatic stability'mechanism which enabled it to maintain its equilibrium upon a single rail, whether standing still or travelling at speed. The mechanism consisted of; .two gyroscopes revolving ■ rapidly >in ..opposite- directions. At the time the model was first exhibited it was practically an undeveloped machine, but since then considerable developments had been made. It was, however, .only about one year'since Brennan had’presented a modified and finished car which would stand a reasonable load. Thus it was not remarkable that it had not yet come into much use. Tho car was’quite safe, and could negotiate curves as easily as a cyclist. Indeed, it bore tho same relation to an ordinary train as a motor-cycle did to a motor-car. There was no tendency, to tip oyer, though the driver could make it tip to one side or the other for any particular purpose. Among the advantages claimed .for tho new system .were the comparative cheapness of installation owing to the use of only one rail, its ability to go into much more inaccessible. places, than a .double-railed oar,, and its ; power -of taking very sharp curves with; safely- The real merit .of Brehhan'&.ihvention lay in his seeing the possibility oY producing much larger-cffects from the gyroscope than anyone had previously sup nosed possible. The more rapidly the gyroscopic disc was rotated..' or the heavier it was, the greater was its power .of righting itself. ; With the aid of two small gyroscopes the professor then demonstrated the wonderful properties) -by a rapidly-rotating disc, after which oxporiments ~were made, with- the.model of ,a' ‘Brennan'car'which had been ‘made in the wprks,hap ~'by J the mechanician. " The gyroscopes on the model were set spinning bv an electric motor,' the professor ..remarking that onerhorsepowet, working ’nor: at least five minutes. was required to get up the necessary speed of' •109 revolutions per second. Tcv stand this ■ enormous speed, ho said, the discs had to be uiadc; of. nickel steel, with a -tensile strength; ofv 75 tons to the rsqiiaro inch. The experiment was 'most successful, . and ./when' the' rfetjuisito speed, had been attained the- model was.run over 1 a . wire rope- stretched , across the room. There it maintained its oquiIfbrium in spite ov tiltihgsf and' vigorous shakings of the rope, the audience marking its approval by hearty applause. In moving 'a vote of thanks to the lecturer,. Mr G. iHogben, Inspector-General of Schools, paid ,a- tribute; to the. interesting ; manner in which Professor Lahy. had explained and made wonderfully clear one of the,, newest developments, in mechanics. : ’ . . The motion : wae seconded by Mr A. L. Beattie, Chief Mechanical Engineer to tho Railway Department, : who ’ said that as a railway engineer .of forty-five -years’ standing he had been particularly interested in the professor's exposition. The motion' was carried with j great heartiness.