Timeline of time measurement technology
From Academic Kids
- 270 BC - Ctesibius builds a popular water clock, called a clepsydra
- 46 BC - Julius Caesar and Sosigenes develop a solar calendar with leap years
- 1000s - Sets of hourglasses were maintained by ship's pages to mark the progress of a ship during its voyage
- 1000s - Large town clocks were used in Europe to display local time, maintained by hand
- 1335 - First known mechanical clock, in Milan
- 1502 - Peter Henlein builds the first pocketwatch
- 1582 - Pope Gregory XIII, Aloysius Lilius, and Christopher Clavius introduce a Gregorian calendar with an improved leap year system
- 1655 - Cassini builds the heliometer of San Petronio (http://cis.alma.unibo.it/NewsLetter/090496Nw/Heilbron.htm) in Bologna, to standardise Solar noon.
- 1656 - Christian Huygens builds the first accurate pendulum clock
- 1676 - Motion works and minute hand introduced by Daniel Quare
- 1680 - Second hand introduced
- 1737 - John Harrison presents the first stable nautical chronometer, thereby allowing for precise longitude determination while at sea
- 1850 - Aaron Lufkin Dennison starts in Roxbury, Mass.U.S.A. the Waltham Watch Company and develops the American System of Watch Manufacturing.
- 1884 - International Meridian Conference adopts Greenwich Mean Time for consistency with Nevil Maskelyne's 18th century observations for the Method of Lunar Distances
- 1893 - Introduction by Webb C. Ball of the General Railroad Timepiece Standards in North America: Railroad chronometers
- 1928 - Joseph Horton and Warren Morrison build the first quartz crystal oscillator clock
- 1946 - Felix Bloch and Edward Purcell develop nuclear magnetic resonance
- 1949 - Harold Lyons develops an atomic clock based on the quantum mechanical vibrations of the ammonia molecule
- 2008 - Launch date for the Primary Atomic Reference Clock in Space.