Contents  > Reference  > Time  > Clocks and Watches

See also:

• Business: Business Services: Supplies and Equipment: Time Recording and Management  (89)
• Computers: Software: Accounting: Time Tracking  (106)
• Computers: Software: Human Resources: Time Keeping Systems  (53)
• Science: Astronomy: Calendars and Timekeeping  (52)

Biological Clocks Virtual Museum This exhibit explores the inputs, outputs, and mechanisms of biological clocks with a primary focus on circadian rhythms. http://www.hhmi.org/biointeractive/clocks/museum.html

Cesium Atomic Clocks Kinds of cesium clocks, with pictures, plus a description of their operation and the science behind them. http://tycho.usno.navy.mil/cesium.html

Doug's Atomic Clocks Details on Doug Hogarth's experiments with his atomic clock. http://www.niceties.com/atomic.html

Green Tyme Using a patented KinderClock Chronichron, this site simultaneously displays both standard time's fixed hours and natural time's variable lengths of days and nights. http://GTyme.org

How Stuff Works: Atomic Clock Concise history, background, definitions and operational information regarding atomic clocks. http://www.howstuffworks.com/atomic-clock.htm

How Stuff Works: Pendulum Clock Concise description using drawings and animation to show the operation of a pendulum clock. http://www.howstuffworks.com/clock.htm

Smithsonian Institute - On Time History of the clock and how Americans have measured time and been affected by it. http://americanhistory.si.edu/ontime/