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Aviation History
1913
1913 - 0745.PDF
JULY 12, 1913. the same point, fixed relatively to the vessel, whatever be the inclination to the horizontal. This cannot hold for W and T unless the latter be central—that is, pass through O. For a flat plane R would generally move forward with a decrease in the angle of attack, and aft when the angle of attack is increased. If the rising of the fore end of the vessel be considerable, the increased angle of attack both of the wind and the water causes the centres of pressure of the planes to travel aft, with the result that R no longer passes through O, but constitutes a clockwise couple tending to bring down the fore end of the vessel until R again passes through O and the cycle recommences. This is one of the causes of pounding, which, besides being severe on the boat, is uncomfortable for those on board. The dipping will be excessive if the period due to skipping synchronises with the natural pitching period of the boat, as then forced oscillations will be set up. The after plane, with its reaction RA, could be done away with, but then the resultant of the wind and water pressure would be much more readily affected in direction by an inclination of the vessel, and so give rise to unbalance in the forces. The arrange ment shown is much more stable, and the reaction RA has the advantage of a small " lift," vertical component, while its horizon- ® ® THE HOLT THO WITH a view to preventing the spread of an accidental fire that has originated round the carburettor on an aeroplane, Mr. Holt Thomas has invented a combination of fusible plug and stop-cock, the arrangement of which is illustrated in the accompanying sketch. The fusible plug, A, is mounted on the top of the carburettor, and its composition is such as to give a sufficiently low melting point to ensure that it will fuse immediately the carburettor is actually enveloped in flames. When the plug fuzes, a lever, B, which the plug formerly held in a certain position, is released. The pull of a spring, C, causes the lever, which is attached to the cock, D, to fly over and to cut off the supply from the fuel tank to the carburettor. At the same time that the supply port in the cock is closed a drain port is opened for the purpose of ejecting the contents of the carbu rettor through a drain-pipe, E, that terminates at some remote part of the machine comparatively removed from the probable danger zone. The recent sad calamity at Shoreham is a reminder of how terrible the consequences of fire may be, and all who are engaged in flying would surely welcome any satisfactory device that might tend to minimise those consequences. It is apparent that in the fitting of the device just described, precaution should be taken to protect the spring as far as possible from the immediate heat of the flame, and it would also, we should think, be thoroughly worth while trying to devise an interconnection of some kind by which the shutting off of the supply cock near the carburettor simultaneously shut off the outlet from the fuel tank itself. This would doubtless present difficulties, but in view of the fact that the petrol pipe may be broken in the sort of accident from which there is most to fear from lire, it would seem thoroughly desirable to try and effect this further safeguard. Whilst on the subject of fire caused by leaking petrol, it may not be inappropriate to reiterate the usual warning to cut off the supply at all costs. Some people appear to feir the explosion of the petrol tank to such an extent that they will even try and break it open to get rid of its contents. Nothing could be more hopelessly dangerous. ® ® Illness of Mr. Joynson-Hicks, M.P. WE tender our sympathy to Mr. Joynson-Hicks, M.P., who has shown so much interest in military aviation, who was taken ill on Monday afternoon at the House of Commons. He is suffering from phlebitis, and although all present engagements have had to be cancelled, Mr. Joynson-Hicks hopes to be well enough to make his statement on military aviation when the Army Estimates come up for discussion again in the House. An Interesting Announcement. ANNOUNCEMENT is made of the forthcoming marriage, on the 29th inst., of Lieut,-Col. C. O. Smeaton, R.A., who, it will be remembered, qualified for a pilot's certificate at the Bristol School in August, 1911, and still flies Bristols at Larkhill and elsewhere whenever he can get an opportunity. His fiancie, Miss Evelyn M. Burnside, who is a daughter of the Rev. F. R. Burnside, Rector of Great Stambridge, where the wedding is to take place, is as keen about aviation as is Col. Smeaton. I/HCHT| tal component, or "drift," which must be overcome by the horizontal component of the propeller thrust, is insignificant. This after plane can be quite small, as it has such a long arm, and its advantages well outweigh its disadvantage. The lift of Rw, RF, and RA, together with the vertical component of T, equal the weight of the vessel, while the horizontal component of T must equal the drift of Rw, RK, and RA. The more the fore end emerges from the water, the shorter will become the planes which bear on the water and which give the greatest drift to be overcome by the propeller thrust, so that we may look for increased speed unless the after end should at the same time sink so far as to increase appreciably the drift at that part. This, however, doss not seem probable with a propeller shaft set at the angle shown, as the increased vertical component of the propeller thrust should compensate for the loss in lift of the planes. All that has been said applies even if T be no longer central but pass above or below O. In either of these cases, however, we must take into account the shift of the meeting point 0 relatively to the vessel. It will readily be seen what effect the moving of O forward or aft of an assumed position, or up or down, will have on the pounding. (To be continued.) ® ® AS FIRE PLUG. There is, of course, danger of the tank bursting if the fire cannot be subdued, but to burst open the tank is to be perfectly certain of consuming in the flames everything that remains. If the petrol " Flight " Copyright. pipe is broken, and the tap inaccessible, the best thing to do is to bend the pipe back on itself, so as to close the orifice by the kink. Particulars of the Mr. Holt Thomas invention can be obtained from the Aircraft Co., 47, Victoria Street, S.W. ® ® Memorial to Army Aviators. ON Saturday last General Sir H. L. Smith-Dorrien unveiled a memorial to Capt. Loraine and Staff-Sergeant Wilson, which has been erected at the junction of the Salisbury-Devizes and Amesbury- Shrewton roads. It takes the form of a Morwenstow cross, in unpolished grey Cornish granite, and it bears the following inscrip tion :—" To the memory of Captain Loraine and Staff-Sergeant Wilson, who, whilst flying on duty, met with a fatal accident near this spot on July 5th, 1912. Erected by their comrades.'' The ceremony was attended by relatives of the deceased officers and representatives of the various branches of the army. Messrs. Lang and Garnett at Wevbridgi. MESSRS. LANG AND GARNETT have removed their offices to their Works—Riverside Works, Weybridge, from where they will transact all their business in future. In order to cope with their increasing business of which a speciality is the turning out of propellers entirely made in England. Messrs. Lang and Garnett are making addition to their plant of modern machinery. 771
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