Christiaan Huygens was a seventeenth century Dutch scientist active in mathematics, mechanics and optics. He is most famous for having developed the world's first pendulum clock. Huygens devised the pendulum clock to solve the key problem facing maritime navigation at the time, the determination of longitude at sea. An accurate clock would solve this problem, allowing mariners to establish the exact time of departure at their home port, and to measure the difference between that time and the local time, therefore establishing their longitude.
Even though the problem of longitude was definitely solved only one hundred years later in 1764 by John Harrison and his marine chronometer, Huygens’ clock had an error of less than 1 minute a day, the first time such accuracy had been achieved, an error Huygens soon managed to reduce to less than 10 seconds a day.
Huygens dedicated his whole classic 1673 work Horologium Oscillatorium (Pendulum Clock), to a complete mathematical description of the pendulum and a description of his improved pendulum clock.
The illustration given here is a composite of four figures. In figure I, the clock is presented from the side; figure II shows the form and curvature of the plates (T in figure I) used for the suspension of the pendulum; figure III the whole clock seen from the outside and figure IV the subdivisions of the pendulum’s rod (VV in figure I).
Sources- Huygens, Christiaan, The Pendulum Clock, or Geometrical demonstrations concerning the motion of pendula as applied to clocks, Blackwell,, Richard J., trans., Ames, Iowa: Iowa State University Press, 1986.
- http://en.wikipedia.org/wiki/Horologium_Oscillatorium
- http://www.17centurymaths.com/contents/huygens/horologiumpart1.pdf (translation)
- http://www.sciencemuseum.org.uk/onlinestuff/stories/huygens_clocks.aspx
- http://www.antique-horology.org/piggott/rh/images/81v_cycloid.pdf pp. 12-14
- http://www.princeton.edu/~hos/Mahoney/articles/huygens/timelong/timelong.html
- http://www.crystalinks.com/clocks.html
- http://galileo.rice.edu/sci/instruments/pendulum.html
- http://www.americanscientist.org/issues/pub/huygenss-clocks-revisited