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Aviation History
1913
1913 - 0072.PDF
l/tiCHT JANUARY 18, 1913. HYDROAEROPLANES. 'Author's Nate.—Revised from a lecture delivered before the Sheffield Mcdel Aero Club, November 28th, 1012. The portion of the lecture which dealt with models has been omitted, and other matter substituted for it. Where certain names or makes of machines are quoted as belonging to certain types, it merely signifies that the makers have constructed such types, not that they have confined themselves to the types specified ; there are, of course, one or two makers who have, practically speaking, confined themselves to onetype, but this is by no means always the case. Generally the best known type is cited. A HYDRO AEROPLANE is a machine capable of travelling oyer the surface of the water, rising from it, flying through the air, and align! ing once again on the surface of the water. A hydro-aero plane Ihen ran be simply an aeroplane in which the wheels are replaced by float?. An aeroplane rises from the ground when it has attained sufficient speed for the downward accelrration which it imparts to the air molecules is sufficient to support its weight in the air. Now it is obviously much easier to obtain the necessary speed while travelling over the surface of firm ground than when tiavelling partly over and partly through a more or less yielding fluid such as water. It is thus quite easy to see that in the new art of flying, the birth of the aeroplane should take place before that of the hydro aeroplane. The initial difficulty in the case of the latter is to travel over the surface of the Water at a sufficient speed in order to reach the necessary velocity for flight, the resistance offered by any form of float being considerably greater than that of wheels. One must not think, however, that the invention of the hydro- aeioplane dates from the year 1912, for a long time previous to that inventors had endeavoured to realise the idea of " getting off" the water. In the early days of aviation, this mode of launching was employed concurrently with launching upon wheels, because the early aviators saw by this means a method of rendering falls less dangerous both to themselves and to their machines. The first hydro-aeroplane to be constructed, and actually put to a practical test, appears to be that of Kress in the year 1901 ; but he had not a motor of sufficient power, and was thus unable to rise, and was finally upset by the wind during a storm. Hargraves had designed and partly constructed what he termed a 'steam aqua-aerial machine—the machine, it would appear, was never completed owing to lack of funds. The manner in which it was proposed to float the machine is worthy of rote. There were By V. E. JOHNSON, M.A. made a flight of 500 metres at a height of about two metres above the water. The machine used was a type of Canard monoplane, with wings carried on a specially constructed girder and the surfacing Fig. 1.—Hargrave's floats. three floats (see Fig. 1), a main central one, whose dimensions were : Length, 25 ft. 7 ins. by 10 ins. in diameter, tapering to 4 ins. in diameter at the tail and 6| ins. in diameter at the bow ; weight 25 lbs. ; two outrigger floats (for lateral balance) 5 ft. 6 ins. long by of ins. in diameter, displacement some 60 lbs. each and weight 24 lbs. ; width over the outriggers, 7 ft. 6 ins. It will be noticed that the design is of the catamarant type. Later on, in France in 1905, Archdeacon and Bleriot made, with Gabriel Voisin, experiments with hydro-aeroplanes, towed by a rapid motor boat. One of the earliest motored aeroplanes con structed by Bleriot was mounted on floats, and experiments were made with it on Lake Enghien ; he was not, however, able to rise from the water, this method of launching requiring too much motive power. It was Henri Fabre who constructed the first successful machine (see Fig. 3), and it rose from the water for the first time on May 21st, 1910, in the Bay of Martigues, near Marseilles, when it t The Cingalese catamaran is a log of wood rounded underneath and scooped out, with two planks lashed on the top. The Mauritius catamaran is an ordinary boat with a smaller boat at the end of the outrigger, in which is set a peculiar kind of mizzen (sail). In the Fijis it becomes a double canoe, with both hulls exactly the same, carrying a platform—having just a little play—so as to permit of the individual peculiarities of the canoes being sufficiently humoured. Should anything go wrong with one of the floats (canoes) the raft simplj- settles on to the surface of the water. Their—comparatively speaking—great breadth renders their lateral stability extremely good, and an ordinary capsize is out of the question. The flying_ proa of the Ladrones, which can travel 20 knots an hour on a beam wind, has its hulls (floats) quite flat on one side (see Fig. 2), and thus avoids the " funnel " difficulty which was found to occur in the case of the Castilia and other steam catamarans, where the inner side of the hull being curved the water was heaped up as it rushed through the narrowing strait. Fig. 2.—A catamaran. was so arranged that it could be " clewed up " in order that less surface should be offered to the wind when floating on the water. It rested on three floats of the " ricochet " type, the plan form of which was square, flat bottorred, with a curved upper surface and set at a rather large angle of incidence, see Fig. 3, one float in front and two behind. Fabre originally held the opinion that only a machine fitted with something quite out of the common in the way of floats would ever rise from the water, and that there were all sorts of difficulties to be overcome in the way of suction, &c., views which we now know to be erroneous. Had some of the experimenters prior to Fabre used machines with more surface, i.e., more lightly loaded, it is quite possible they would have anticipated him. P'abre also made other flights besides the one referred to, one an excellent Fig. 4.—Cuitiss's first machine. flight (June, 1910) of six kilometres at a height of 20 metres, but he alighted at too steep an angle and the machine upset. During 1905 experiments were made by Dr. Barton and Mr. Rawson at St. Helens in the Isle of Wight with a motorless machine towed by a launch. The most interesting part of their machine were the pontoons or floats on which the machine rested, the dimensions were 20 ft. long by 10 ins. wide and 4 ins. deep, the bottom and top were straight, save that the bottom sloped upwards towards the bows and the top downwards towards the stern. The weight of each float was 26 lbs. In America Professor Langley carried out bis experiments over water. In the autumn of 1908 Glen Curtiss mounted his well-known aeroplane "June Bug " on two canoe-like floats, which resembled the type used in certain forms of catamarans (already described). Now, although this was a machine that had flown well over land, and could be made to travel quite fast on the water, the speed 72
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