KITE PHOTOGRAPHY (Fr., La photographie par cerf-volant ; Ger., Drachenphoto graphie) Photography by means of a camera attached to, or suspended from, a kite is of frequent use in obtaining bird's-eye views for military pur poses, and as an aid to the surveyor and meteor ologist. A. Batut, of Enlaure, Prance, was the first to devote special attention to this class of work. In 1887 he employed a large diamond shaped kite, as illustrated, having a long tail to give stability. The camera A was fastened to the kite by a triangular support, and had a shutter B of the guillotine type, working hori zontally by means of two rubber bands. The shutter was held in tension by a thread, which was burnt through by a slow fuse C, ignited before flying the kite. In its passage across the lens the shutter was made to release a paper streamer, thus announcing that the exposure had taken place. Flat films were used. To prevent obstruction of the view by the cord, this was attached by a kind of double bridle to a bar D. A self-registering barometer E indi cated the height attained.
E. Wenz, in Germany, used shortly afterwards a kite of similar shape, but with the camera fastened to the bridle cords. Since then, kite cameras of a much more elaborate kind have been employed. As an example may be mentioned one made in 1899 by L. Gaumont, of Paris, for the use of A. Lawrence Rotch, of the Blue Hill Meteorological Observatory, near Boston, Massa chusetts. While primarily intended for photo
graphing the under surface of clouds, this could be employed also for obtaining views of the surrounding country. Clockwork allowed of successive exposures on a roll of film at pre determined intervals. Electric releases and simple cord releases operated from the ground have also been used.
The kite employed for photographic purposes must be steady in the air, the box kite and the multicellular oblique type being now preferred to the older pattern. The camera, which should be as light as possible, and of the fixed-focus box-form variety, carrying films, is now usually attached to, or hung from, the cord. A simple method of making the exposure, suitable for experimental use, is as follows : A rubber band, one end of which is fastened to a small staple, is stretched over the trigger release of the shutter, and the latter is set back against the pull of the rubber by a thread tied to another staple as far away from the lens as possible. A sufficient length of ordinary wool soaked in a strong solution of potassium nitrate and dried is then tied to the further end of the thread, and ignited when the kite is ready to be flown. The slowly-burning fuse will eventually sever the thread, and thus enable the rubber band to work the trigger release of the shutter.