Show Ears of f Anti-Aircraft Anti ors o Artillery I T I I f j v L yi 4 z 1 Photograph shows one of the new streamlined sound detectors the army tested during theair the air corps and aircraft defense maneuvers In North Carolina The listening horns arc are made of balsa wood with rounded edges and a n cellulose acetate covering They have no greater hearing power potter than the old style but are more effective in shutting out all but plane noises Thus searchlights and guns of or the anti-aircraft anti batteries can be trained more efficiently on attacking planes |