  Mr. Fred. W. Brearey has been the honorary secretary of the Aeronautical Society of Great Britain ever since its establishment in 1866. In the course of his experiments, extending over some years, he found that if a serpentine action were imparted to a fabric it would propel an attached object many times its weight in the air. He records in his published magazine articles that he took the idea from watching the movements of a skate in an aquarium, which in swimming undulated its whole body. In applying the principle to locomotion in air, it is of course impossible to undulate what may called the backbone of the whole structure in the manner of the skate. But a fabric may be so attached to a receptacle, and so worked from thence by a suitable motive power, that its undulations will propel and support a considerable weight, depending upon the energy with which such fabric is thrown into waves. He believes that the awning of a vessel can be made in this way to contribute to a ship's progress at the same time that it would cool the passengers. Mr. Brearey argues that the instinct of the bird enables it to adapt itself instantaneously to varying circumstances; that in any arrangement for effecting flight by machinery—the adjustment of parts to meet sudden requirements being a matter requiring momentary thought—it is desirable, if practicable, to employ large surfaces for parachutic action, at the same time making this means of safety not an incumbrance, but an aid. The possession of instinct allows of the employment of the smallest surface in proportion to weight; the possession of forethought renders it necessary that intermittent action shall be safeguarded by large surfaces. This requirement is fully met, the inventor says, by the arrangement advocated by him, and none but edge resistance is offered to the air, except the sharp lines of the necessary vehicle. The manufacture of such an apparatus upon a scale of utility would be as follows: A flat-bottomed receptacle, somewhat of boat shape, would be fixed upon wheels. At the fore part of the boat a motor would from each side elevate and depress two wing-arms, each 15 ft. long. (See Figure.) Along the wing-arms is attached a fabric which would form the front part of a kite, which, being fastened in the center to the edge of the boat, would continue for 15 ft. to the rear, being extended about 6 ft. farther than the stern of the boat by a continuing spar. To a cross piece here would be fastened the tail end of the kite, which, however, instead of a point, would be about 5 ft. in width. From this again would extend a tail of about 12 ft., to which either a lateral, twisting, or a vertical movement could be imparted by cords in the hands of the operator in the boat for steering purposes. From the fore part of the boat would extend a bowsprit, from which cords would be attached to the two wing-arms to prevent the weight of the fabric from dragging them backward. An important arrangement has been adopted by the inventor, which he calls the pectoral cord, which by its automatic action assumes the functions of the pectoral muscle of the bird. This is an India-rubber cord. It is attached by its two extremities to the under portion of each wing-arm, and in models passes underneath a central shaft—in this case the boat. Its degree of elasticity is regulated by the weight. When any model with wings is committed to the action of the air, the pressure of the air causes the wings to fly upward, and power is required according to the weight sustained to depress the wings against the weight. The strength of the cord, however, is such that it maintains the outstretched wings at that angle which is suitable for gliding upon the air without, in the case of the bird, any enforced muscular exertion. The contraction of this cord assists the power exerted in the downward stroke. The wing arms would not be rigid throughout their length. They would consist of a number of rattans or canes firmly bound together by close wrapping, and tapered by cutting A small model upon this principle, but without any motive power, was liberated as an experiment by Captain Templer, from a balloon which had risen 200 ft. or 300 ft. from Woolwich Arsenal, and it traveled back again to the arsenal half a mile against the wind uninjured. The importance of such an apparatus might become manifest in any flight of a balloon from a besieged place over the heads of an investing army. The results of a rapid survey of the enemy's positions could be written and dispatched from a height against the same current which wafted the balloon, so as to fall within the lines of the besieged. Given a light motive power, which it is hoped may soon be forthcoming, Mr. Brearey anticipates the action of the machine as follows: A surface will be provided according to the weight to be carried, the supporting surface of a parachute being known. Upon being run down an incline the envelope will be inflated by the pressure of the air, and the wing arms raised to that point where their further elevation is restrained by the pectoral cord. The machine will then naturally float away from the incline, and the occupant must set his motor in action. The downward blow of the wing-arms will cause the fabric immediately attached thereto to imprison a mass of compressed air, and the following wave will force it along the under side of the fabric. This will cause propulsion. The return or up stroke cuts off and diverts from the upper part that air which, but for the rise of the wing-arms, would flow over the back, and shunts it underneath, while that which is embraced in the concave fabric following the up-stroke is thrown off in a wave to the rear above the machine, and so on alternately. During this energetic action the whole fabric is kept in a state of corrugation, and to such extent is rigid. It possesses all the properties of a plane, and superiority over a plane, inasmuch as it propels itself, and upon cessation of action assumes the functions of a parachute, the descent of which a man may regulate by a step backward or forward. The latest invention which has been completed upon a full scale is the idea of Mr. H. C. Linfield, of Margate. It is really a plane-propelling machine, but the planes are compressed, it may be said, into small compass, being only two inches apart, and being of such number and extent as to present 438 square feet of strained and varnished linen in two frames, each five feet square. The dimensions of the machine are 20 ft. 9 in. in length, 15 ft. in width, and 8 ft. 3 ins. in height. It runs upon four wheels; the two front wheels are 6 ft. in diameter, the two hind wheels 3 ft. The frames before mentioned are fixed one on each outer side of the front wheel at an upward angle. The wheels have been tested to sustain a weight of 5 cwt. The weight of the machine is 240 lb., and of its inventor 180 lb. He sits between the wheels and works two treadles, which actuate a nine-bladed screw 7 ft. in diameter, fixed in front of the machine, to which he can impart 112 revolutions per minute. This suffices to enable him to travel along a level road. |
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