This strange object was built on the coast of Great Britain. What is it?
sun clock
storm detector
acoustic mirror
emergency radio receiver
Prior to World War II and the invention of radar, acoustic mirrors were built as early warning devices around the coasts of Great Britain, with the aim of detecting airborne invasions. The development of radar put an end to further experimentation with the technique.
reach: rather globalGreat BritainsoundtechnologyUnited KingdomWorld War I
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sun clock
storm detector
acoustic mirror
emergency radio receiver
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