The “Flight” of Flying-fish

Abstract

HAVING read with interest the letters by Prof. Wood-Jones and Mr. Julian S. Huxley in NATURE for April 21 and 28 respectively, I send some observations of my own which seem to have a bearing on this subject. In the early 'nineties I was engaged in the development of the meteorological kite of the Hargrave pattern, which was adopted at the Blue Hill Observatory for lifting self-recording apparatus in the air, and later adopted by the various bureaus of the world for aerological research. This work brought me in contact with the early pioneer workers on the problem of flight in the United States—Langley, Chanute, the Wrights, Cabbot, Means, Millet, and others—and I occasionally co-operated in experiments on the lifting and driving powers of various devices. One of these was a device in which a stiff rod had attached to one end a flexible rod of bamboo, one end of the bamboo strip being tied near the end of the rigid rod and the other about one-fourth of the way down, so that the bamboo rod formed a loop, over which was drawn a covering of cloth. Now, if one took the free end of the rigid rod and waved the end containing the bamboo loop up and down, he was immediately turned round by a forward motion of the outer end of the rigid rod. The reason of this clearly was that when he lifted the rigid rod upward the flexible loop bent downward, and there was a component of air pressure forward, while when he moved the rigid rod downward the flexible loop bent upward, and there was still a component of air pressure forward. When vibrating the rod up and down there was a persistent forward thrust, and this thrust was so great when the vibration was rapid that the operator was turned completely around in his tracks as on a pivot.