On This Day (April 4)

[MSFixR]

• 1581 - Francis Drake completes a circumnavigation of the world and is knighted by Elizabeth I.
• 1617 - John Napier, Scottish mathematician died. (b. 1550) (Napier was a Scottish mathematician, physicist, astronomer/astrologer and 8th Laird of Merchistoun, son of Sir Archibald Napier of Merchiston. He is most remembered as the inventor of logarithms and Napier's bones, and for popularizing the use of the decimal point. Although not invented by Napier, the slide rule, an analog computer, is based on logrithms.)
• 1660 – Charles II of England issued the Declaration of Breda, describing his conditions for the Restoration of the crown of England.
• 1721 – Robert Walpole took office as First Lord of the Treasury, Chancellor of the Exchequer and Leader of the House of Commons, becoming the first British Prime Minister, though the term "Prime Minister" was not used at the time.
• 1884 - Isoroku Yamamoto, Japanese naval commander born. (d. 1943) (Yamamoto was Commander-in-Chief of the Combined Fleet during World War II, graduate of Imperial Japanese Naval Academy and an alumnus of U.S. Naval War College and Harvard University (1919–1921).)
  
  
  Isoroku Yamamoto
  
  
• 1923 - John Venn, British mathematician died. (b. 1834) (Venn was a British logician and philosopher, who is famous for the Venn diagrams, which are used in many fields, including set theory, probability, logic, statistics, and computer science.)
• 1949 – Twelve nations signed the North Atlantic Treaty, creating NATO.
• 1968 – American civil rights leader Martin Luther King, Jr. was assassinated on the balcony of the Lorraine Motel in Memphis, Tennessee.
• 1969 – Surgeons Denton Cooley and Domingo Liotta implanted the first total artificial heart.
• 1975 - Microsoft is founded as a partnership between Bill Gates and Paul Allen.
• 1976 – Norodom Sihanouk abdicated from the role of leader of Cambodia and was arrested by the Khmer Rouge.
  
  
  Picture of the Day
  
  
  This false-color mosaic showing compositional variations in the geology of the Moon was constructed from a series of 53 images taken through three spectral filters by the imaging system of the Galileo spacecraft. Bright pinkish areas are highlands materials, such as those surrounding the oval lava-filled Mare Crisium impact basin toward the bottom. Blue to orange shades indicate volcanic lava flows. To the left of Crisium, the dark blue Mare Tranquillitatis is richer in titanium than the green and orange maria above it. Thin mineral-rich soils associated with relatively recent impacts are represented by light blue colors. The monochrome band on the right edge shows the unretouched surface of the moon