In 1931 – Friedrich Schmiedl launched the first rocket mail (V-7, Experimental Rocket 7) with 102 pieces of mail between Schöckl and St. Radegund, Austria.
In 1935 – Detective Leonarde Keeler, co-inventor of the Keeler polygraph, tried out the lie detector on two suspected criminals in Portage, Wisconsin. Both suspects were convicted of assault.
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