First built in the 1920's, and predating the use of Radar in World War II, early warning "sound mirrors" were used to provide some means of detecting incoming enemy aircraft. First used in World War I to listen for Zeppelins, their vestigial remnants dot the English coastline. The bizarre legacy of the sound collectors lives on through some decidedly nerdy enterprises.
posted by basicchannel on Apr 7, 2005 - 27 comments