<P> The chronometer was trialled in 1761 by Harrison's son and by the end of 10 weeks the clock was in error by less than 5 seconds . </P> <P> In 1815, Sir Francis Ronalds (1788 - 1873) of London published the forerunner of the electric clock, the electrostatic clock . It was powered with dry pile s, a high voltage battery with extremely long life but the disadvantage of its electrical properties varying with the weather . He trialled various means of regulating the electricity and these models proved to be reliable across a range of meteorological conditions . </P> <P> Alexander Bain, a Scottish clock and instrument maker, was the first to invent and patent the electric clock in 1840 . On January 11, 1841, Alexander Bain along with John Barwise, a chronometer maker, took out another important patent describing a clock in which an electromagnetic pendulum and an electric current is employed to keep the clock going instead of springs or weights . Later patents expanded on his original ideas . </P> <P> The piezoelectric properties of crystalline quartz were discovered by Jacques and Pierre Curie in 1880 . The first quartz crystal oscillator was built by Walter G. Cady in 1921, and in 1927 the first quartz clock was built by Warren Marrison and J.W. Horton at Bell Telephone Laboratories in Canada . The following decades saw the development of quartz clocks as precision time measurement devices in laboratory settings--the bulky and delicate counting electronics, built with vacuum tubes, limited their practical use elsewhere . In 1932, a quartz clock able to measure small weekly variations in the rotation rate of the Earth was developed . The National Bureau of Standards (now NIST) based the time standard of the United States on quartz clocks from late 1929 until the 1960s, when it changed to atomic clocks . In 1969, Seiko produced the world's first quartz wristwatch, the Astron . Their inherent accuracy and low cost of production has resulted in the subsequent proliferation of quartz clocks and watches . </P>

Who made the first clock and how did they know what time it was