2nd » Leonarde Keeler tests the first polygraph machine.
7th » The classic board game Monopoly (game) e.g Monopoly is invented.
12th » USS Macon ZRS-5 6, one of the two largest helium-filled airships ever created, crashes into the Pacific Ocean off the coast of California and sinks.
13th » A jury in Flemington, New Jersey finds Bruno Hauptmann guilty of the 1932 kidnapping and murder of the Lindbergh kidnapping e.g Lindbergh baby, the son of Charles Lindbergh.
20th » Caroline Mikkelsen becomes the first woman to set foot in Antarctica.
26th » Adolf Hitler orders the Luftwaffe to be re-formed, violating the provisions of the Treaty of Versailles.
26th » Robert Watson-Watt carries out a demonstration near Daventry which leads directly to the development of radar in the United Kingdom.