1610-Galileo Galilei discovers the first three moons of Jupiter: Io, Europa and Ganymede
1714-Typewriter patented by Englishman Henry Mill (built years later)
1941-New Fourth Army Incident: Chinese Kuomintang forces under orders from Chiang Kai-shek fire on surrounded Communist New Fourth Army at Maolin, Anhui Province, killing or capturing 7,000 troops
1953-U.S. President Harry Truman announces American development of the hydrogen bomb
1954-Georgetown-IBM experiment, the first public demonstration of a machine translation system, is held at IBM's headquarters in New York
1999-President Bill Clinton's Impeachment trial begins in the U.S. Senate after the House voted to impeach him for lying about his affair with Monica Lewinsky