Template:Selected anniversaries/April 13
1771: Engineer and explorer Richard Trevithick born. Trevithick will be an early pioneer of steam-powered road and rail transport, developing the first high-pressure steam engine, and building the first full-scale working railway steam locomotive.
1889: Cryptologist and author Herbert Yardley born. Yardley will found and lead the Black Chamber, a secret American government cryptographic organization which will break Japanese diplomatic codes, furnishing American negotiators with significant information during the Washington Naval Conference of 1921-1922.
1905: Engineer Charles Renard commits suicide. Renard pioneer the design and construction of airships. He also proposed a set of preferred numbers now known as the Renard series.
1927: Theoretical physicist Mendel Sachs born. Sachs' work will include the proposal of a unified field theory that brings together the weak force, strong force, electromagnetism, and gravity.
1953: CIA director Allen Dulles authorizes the secret drug research program Project MKUltra, intended to identify and develop drugs and procedures to be used in interrogations and torture, in order to weaken the individual and force confessions through mind control.