Explosion waves and shock waves. Part I.—The wave-speed camera and its application to the photography of bullets in flight

• Published in: Proceedings of the Royal Society of London. Series A, Containing papers of a mathematical and physical character Containing papers of a mathematical and physical character, 1931-07, Vol.132 (819), p.200-213
• Main Authors: Payman, William, Woodhead, Donald Whitley
• Format: Article
• Language: English
• Subjects: Bullets; Cameras; Gases; Photographic lenses; Rifles; Schlieren photography; Shock waves; Shutters; Tracer bullets; Trajectories
• ISSN: 0950-1207; 2053-9150
• DOI: 10.1098/rspa.1931.0095

Photographic Methods for Measuring Velocities.—Two methods have been used to determine rates of detonation in gases, the chronographic method first used by Berthelot and Vieille and the photographic method of Mallard and Le Chatelier. The second method has proved the more useful in practice and, as developed by the late Professor H. B. Dixon, has been adopted almost universally by other workers. Not only has it the advantage that it provides a means of measuring the rate of detonation in short columns of gas, but it also allows the after movements of the flame and gases to be analysed. The method makes use of a revolving drum around which a sensitised film is wrapped. A camera lens gives an image of the horizontal glass tube containing the explosive mixture as a horizontal line across the width of the film. As the drum rotates on its horizontal axis, the film has a motion which is sensibly vertical at the focus of the lens, so that the image records an inclined trace compounded of the horizontal movement of the flame and the vertical move­ment of the film.