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.
Like Tech History? Get the illustrated Year in Tech History at Merritt’s Books site.