1642 in science

Astronomy

• Rundetårn astronomical observatory for the University of Copenhagen is completed, as is also the Panzano Observatory.

  Computing

• 19-year-old Blaise Pascal begins to develop the Pascaline, the first practical mechanical calculator, initially to help with the recording of taxes.

  Exploration

• November 24 – Abel Tasman, Dutch explorer, is the first European known to sight Tasmania, which he names Anthoonij van Diemenslandt.
• December 13 – Tasman is the first European known to sight New Zealand.

  Technology

• Opening throughout of the Briare Canal in France, the first summit level canal in Europe built using pound locks.
• The printmaking process of mezzotint is developed by Ludwig von Siegen.

  Births

• March – Seki Takakazu, Japanese mathematician
• December 25 – Isaac Newton, English polymath

  Deaths

• January 8 – Galileo Galilei, Italian astronomer