This device, which used sound to find aircraft, was operated in conjunction with 13-pounder anti-aircraft guns. Tubes connected the bases of two horizontal, gramophone-style horns to a pair of stethoscope earpieces. An operator moved the detector until he heard sound equally in each ear, at which point, ideally, the guns could be pointed in the direction of the aircraft. The two vertical cones estimated the target's height.
Sound Locator
CWM 19440018-001
Canada and the First World War
