Clocks

Appearance of first small domestic (table) clocks.

The first mechanical watch's were created in German cities of Nuremberg by Peter Henlein. These models were either fastened to belts or carried around the neck and they measured only passage of hours.

Screws became used for clocks, enabling much smaller designs that kept time much better than first models.

First public tower clock fixed on one of the towers in Hampton Court Palace, England.

Jost Burgi invented the minute hand, even though 16th century clocks were very inaccurate.

Italian astronomer and physicist Galileo discovered the properties of pendulum.

Geneva became home to the thriving watch making industry.

Introduction of protection glass on watches. This finally enabled reliable protection of time dials on the portable small watches.

French inventor and clockmaker Paul Viet of Blois introduced first enamel dials.

Famous Dutch physicist Christiaan Huygens created first pendulum controlled clock.

Pendulum clocks received important upgrade with the introduction of pendulum suspension spring introduced by William Clement.

Nicholas Facio managed to pierce rubies and sapphires, using them as a jeweled bearing for balance staff pivots.

Several important watch inventions - George Graham invented mercurial compensation pendulum and dead-beat escapement for clocks, John Harrison invented grid-iron compensation pendulum and George Graham invented the cylinder escapement.

Enlightenment era in Europe brought many advances to clock mechanisms. Need for accurate maritime chronometers soon enabled ordinary and cheap watches to become very accurate. This accuracy can be attributed to the inventions of Pierre Le Roy and Thomas Earnshaw who introduced to the public temperature compensated balance wheel.

First electric clock was created by Edinburgh clockmaker Alexander Bain.

Standardization of time zones. England received GMT time zone with Greenwich becoming prime meridian for measuring longitude in entire world.

First modern electric clock created by Frank Hope-Jones. This clock became base of all modern clocks that are created today.

Clocks and personal watches enter into mass production.

Radio time signals became transmitted from Washington DC to help ships find longitude on open seas.

Introduction of Summer Time.

Physicist Isador was first to suggest that oscillations of atoms (atomic-beam magnetic resonance) can be used to create extremely precise clocks.

First atomic clock created by United States National Institute of Standards and Technology (NITS).

Second is formally defined not through movements of celestial bodies but as 9,192,631,770 vibrations of the cesium atom.

Over half a billion watches are sold every year.