Acoustic Mirrors at Denge, a site of the British Royal Air Force near the Channel, where some experimental models were built in the 1920s and 1930s. One is…
Dutch personal horns. Rotating acoustic listening device developed for the Dutch army as part of air defense systems research between World Wars I and II, 1930s.
German acoustic/optical locator, 1917. A junior officer and an NCO from an unidentified Feldartillerie regiment wearing combined acoustic/optical locating apparatus.
Japanese ‘War Tuba’ in an air field, 1921. After WWI aircraft detection became increasingly important to warfare. Before radars acoustic amplifiers and mirrors with different designs were used…
Athanasius Kircher, Musurgia Universalis (1650) An early example of a plan to build a pansonic device, capable of bringing the sounds from the public space up to the…
Wire Recorder Saves Time by Handling Data on Photographs, Popular Mechanics, Dec, 1950 Photographers who do considerable work in the field can save time by using a wire…