important events 1910-1930 By Elena Sendejas Aug 5, 1910 Halley's comet makes an appearance Oct 1, 1910 boy scouts established in the U.S Dec 1, 1910 time tango catches on May 1, 1920 The leagues of nations established Nov 4, 1920 Pluto discovered Dec 4, 1920 Bionic plaque in India Aug 4, 1923 first commercial/radio broadcast aired Oct 1, 1926 Harlem Renissance begins Oct 1, 1930 Gandih's salt march Oct 1, 1936 Agriculture in the U.S.S.R