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
Answers by country
sun clock
storm detector
acoustic mirror
emergency radio receiver
answers
New Zealand
11
Germany
70
Poland
18534
Unknown
19
the United Kingdom
592
Czech Republic
15
Canada
34
Spain
23
France
17
the United States
323
Australia
64
Sweden
13
the Netherlands
21
Greece
13
Republic of Ireland
29
Russia
15
Indonesia
11
Rwanda
11
India
160
the Philippines
12