July 11, 1884.] 



♦ KNO^VI_EDGE ♦ 



27 



question that mechanicians can devise the means of obtain- 

 ing at least a sufficient velocity of motion to raise either a 

 man or a flying machine, provided with no greater extent 

 of supporting surface thau would be ruauagt-able in either 

 case. It is not tlie difficulty of obtaining from the air at 

 atartiwj the requisite supporting power that need deter the 

 aeronaut. The real dittiLulties are those which follow. 

 The velocity of motion must be maintained, and should 

 admit of being increased. There must be the means of 

 increasing the elevation, however slowly. There must be 

 the means of guiding the aeronaut's flight. And lastly, the 

 aeronaut or the flying-macliine must fly with well-preserved 

 balance — the supporting power of the air depending en- 

 tirely on the steadiness with which the supporting surfaces 

 traverse it. 



I believe tliat these difficulties are not insuperable : and 

 not only so, but that none of the failures recorded during 

 the long history of aeronautical experiments need discourage 

 us from hoping for eventual success. Nearly all those 

 failures have resulted from the neglect of conditions which 

 have now been shown to be essential to the solution of the 

 problem. Xothing but failure could be looked for from the 

 attempts hitherto made i and, indeed, the only wonder is 

 that failure has not been always as disastrous as in the case 

 of Cooking's ill-judged descent. If a man who has made 

 no previous experiments will insist on jumping from a 

 summit of a steeple, with untried wings attached to his 

 arms, it cannot greatly be wondered at that he falls to the 

 ground and breaks his limbs, as Allard and others have 

 done. If, notwithstanding the w-ell-known weakness of the 

 human breast-muscles, the aeronaut tries to rise by flappinj; 

 wings like a bird's, we cannot be surprised that he should 

 fail in his purpose. Nor, again, can we wonder if his at- 

 tempts to direct balloons from the car should fail, when we 

 know the car could not even be drawn with ropes 

 against a steady breeze without injury to the supporting 

 balloon. And we need look no further for the cause of the 

 repeated failures of all the flying-machines yet constructed, 

 than to the fact that no adequate provision has yet been 

 made to balance such machines, so that they may travel 

 steadily through the air. It seems to have been supposed 

 that if propelling and elevating power were supplied the 

 flying-machine would balance it-elf; and, accordingly, if 

 we examine the proposed constructions, we find that in 

 nine cases out of ten (if not in all) the machine would be as 

 likely to travel bottom-upwards as on an even keel. The 

 common parachute (which, however, is not a flying-machine) 

 is the only instance I can think of in which a non-buoyant 

 machine for aerial locomotion has possessed what is called a 

 "position of rest." 



Perhaps the gravest mistake of all is that of supposing 

 that, on a tirst trial, a man could balance himself in the 

 air by means of wings. Placed, for the first time, in deep 

 water, man is utterly unable to swim, and it lett to him- 

 self will inevitably di own ; although a very slight and very 

 easily-acquired knowledge of the requisite motions will 

 enable him to preserve his balance. And yet it seems to 

 have been conceived by most of those who have attempted 

 flight, that when first left to himself in open air, with a 

 more or less ingeniously-contrived apparatus attached to 

 him, a man would not only be able to balance himself in 

 that unstable medium, but also to resist the down-drawing 

 action of gravity (which scarcely acts at all on the swimmer), 

 and wing his way through the air by a series of new and 

 untried movements ! 



It encourages confidence in the attempts now being made 

 to solve the problem of aerial locomotion, that they are ten- 

 tative — founded on observation and experiment, and not 

 on vague notions respecting the manner in which birds fly. 



Fresh experiments are to be made, more particularly on the 

 suppoiting power of the air upon bodies of diflerent form, 

 moving with diflerent degrees of velocity. These experi- 

 ments are under the charge of Messrs. Browning and Wen- 

 ham, of the Aeronautical Society, whose skill in experi- 

 mental research, and more particularly in inquiries de[iend- 

 ing on mechanical considerations, will give a high value to 

 their deductions. The question of securing the equipoise of 

 flying-machines has also received attention ; and it is pro- 

 bable that the principle of the instrument called the gyro- 

 scope will be called into action to secure steadiness of 

 motion, at least in the experimental flights. What this 

 principle is need not here be scientifically discussed ; but it 

 may be described as the tendency of a rotating body to 

 preserve unchanged the direction of the axis about which 

 the body is rotating. The spinning-top and the quoit (well 

 thrown) afl!br(l illustrations of this principle. The peculiar 

 flight of a flat mi-ssile, already referred to, depends on the 

 same principle ; for the flight only exhibits the peculiarities 

 mentioned when the missile is caused to whirl in its own 

 plane. But the most striking evidence yet given of the 

 steadying property of rotation is that afforded by the experi- 

 ments ot Professor Piazzi Smyth, the Astronomer Royal for 

 Scotland. During the voyage to Teneriffe (where, it will 

 be remembered, his well-known Astronomer's Experiment 

 was carried out), he tested the power of the gyroscope in 

 giving steadiness, by causing a telescope to be so mounted, 

 that the stand could not shift in (losition without changing 

 the axial pose of a heavy rotating disc. The disc was set 

 in rapid rotation by the sailors, and then the Professor 

 directed the telescope towards a ship on the horizon. A 

 fresh wind was blowing, so that everything on deck was 

 swayed in lively sort by the tossing vessel ; nor did the 

 telescope ieem a whit steadier- —the motion of objects round 

 it giving to the instrument an appearance of equal in- 

 stability. But the officers were invited to look through the 

 tube, and to their amazement, the distant ship was seen as 

 steady in the middle of the telescopic field as though, in- 

 stead of being set up on a tossing and rolling ship, the 

 telescope had been mounted in an observatory on terra 

 firma. The principle of the gyroscope has also been used 

 for the purpose of so steadying the stand of a photographic 

 camera placed in the car of a balloon, that photographs 

 might be taken despite the tendency of the balloon to 

 rotate. As applied to flying-machine-, the gyroscope would 

 require to be so modified in form that its weight would not 

 prove an overload for the machine. This is practicable, 

 isecause a flat horizontal disc, rotating rapidly, will support 

 itself in the air if travelling horizontally forward with 

 adequate swiftness. In other words, since travelling- 

 machines must travel swiftly, the gyroscopic portion of the 

 machine may be made to support itself. 



It is this property of enforced rapidity of motion which 

 renders the probable results of the mastery of our problem 

 so important. It has been well remarked that two problems 

 will be solved at once, when the first really successful 

 flying-machine has been made — not only the problem of 

 flight, but the problem of travelling more swiftly than by 

 any contrivances yet devised. In the motion of a flying- 

 machine, as distinguished from the flight of man by his 

 own exertions, the swiftness of the bird's flight may be 

 more than matched. It is a mere mechanical problem 

 which has to be solved ; and few mechanicians will deny 

 that when once the true principles of flight have been 

 recogni>ed, the ingenuity of man is capable of contitructing 

 machines in which these principles shall be carried out. 

 Iron and steam have given man the power of surpassing 

 the speed of the swiftest of four-footed creatures — the 

 horse, the greyhound, and the antelope. We have full 



