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 aeronautics 102 but this was still very good. The equilibrium was defecever before. It can no longer be said that men have neve" tive and greatly shortened the possible flights. A score of different models have been flown through the air. The preceding table (p. 101) exhibits produced by Hargrave, of New South Wales, since 1885. His No. 16 has been selected for the table given. It consisted in a body plane of kite shape, propelled by a pair of flapping vanes at the front (Figs. 1, 2, 3). Hargrave built a number of steam - engines weighing about 10 lb per h.p., but found such difficulties that he turned his attention to oil motors. He advocates large surfaces and low speeds, and hopes to maintain those proportions by sus(From Engineering.) pending a motor and propellers Fig. 1.—General appearance of Hargrave’s flying machine. from a tandem team of the “ Cellular Kites ” which he has the more important performances, and attention is called to invented, and with which he has been lifted from the the columns of pounds imposed per square foot, to the resu ground. The apparatus of Phillips resembles a Venetian blind. The slats are of wood, convex on the upper surface and concave beneath. The lift is apparently ^ery good, but the stability is defective. After many preliminary experiments on air reactions, Maxim tested, .in 1894, a very large flying machine, a marvel of ingenuity and mechanical skill, carrying three men. It consisted in a combination of superimposed aeroplanes, driven by two screw propellers, which were rotated by a.compound steamengine of 363 h.p., weighing with its adjuncts some 10 ft) per h.p. The apparatus gathered speed on a railway track, and demonstrated that it could lift much more than its own weight; but the pounds sustained per h.p. were less than was expected, probably by reason of head resistance caused by many guy wires, and the stability was inadequate. After publishing his Experiments m Aerodynamics in 1891, Langley produced in 1896 a steam-driven flying model, with which he obtained the longest flights

Fig. 2.—Engine for Hargrave’s flying machine. From Engineering.) ing speed required for support, and to the pounds sustained per horse-power (the apparatus marked thus * carried a man or men). The first aeroplane of Tatin (1879) consisted of a pair of flat wings and a . tail, traction being obtained from two screw propellers at the front. The horsepower was arrived at by allowing 25 to 30 per cent, of that shown by the indicator for the compressed When Tatm and Kichet substituted steam in 1897 they only sustained about half as many pounds per h.p.;

Fig. 3.—Another type of engine for Hargrave’s flying machine. (From Engineering.) ever known. The apparatus consisted of two pairs of wings and a tail, with two screw propellers, driven by a high pressure steam-engine of 1 h.p. weighing but 7 ft. The longest flight was over f of a mile, and the appa ratSs alighted safely on each of the three flights made. The lift per horse-power was low, for a variety of reasons, but the stability was good. After having tested,. in 1879 and 1891, two full-sized flying machines, producing indifferent results, Ader built, in 1897 a third apparatus with funds furnished by the French Government. This reproduced the structure of a bird with almost servile imitation, save that traction was obtained by two screw pro-