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January 14, 2019

Sound Mirrors of England

From the BBC: "More than 100 years ago, acoustic mirrors along the coast of England were used to detect the sound of approaching German zeppelins. The concave concrete structures were designed to pick up sound waves from enemy aircraft, making it possible to predict their flight trajectory, giving enough time for ground forces to be alerted to defend the towns and cities of Britain."

January 14, 2019 at 12:01 PM | Permalink


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