Feb 22
This is one of those weird things in history that you never learn in school or see on the History Channel. These devices were used during World War I to detect airplanes and airships (Blimps) that might be on their way to attack Great Britain.They were the World War I version of the radar that we have today. From everything that I read they worked quite well and were even able to tell from what direction the enemy was approaching.
During World War II they used a much larger concrete version. I did a post on this a while back and I will put the link down at the bottom of the page.
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WWII Sound Mirror . . . World War II W.A.S.P.
