My mom was about twelve during this period of WWII and remembers the neighborhood meetings of warning and watchfulness about the balloons. She lived about 20 miles from San Pedro, CA.
Karan
There was a good program on channel 4 where ex raf man who won scrapheap challenge a few times built one of these. It was ingenius. He also build other great things like a steath boat for 200 quid which fooled 16k worth of state of the art rader by using foil and acoustic foam. And a dummy tank that fooled a air to surface missile targeter on a harrier
Danny