The collection’s most significant and special timepieces are the ground-breaking group of clocks by Abraham Louis Breguet (1747-1823).

This presupposes that a clock has been placed at each point of the reference frame and that this clocks set is synchronized.

It is derived from International Atomic Time (TAI), itself based on the atomic definition of the second and measured using a series of atomic clocks.

These radioactive processes present a set of natural clocks which reveal when the rock was formed, or when it was last heated severely.

These radioactive processes present a set of natural clocks which reveal when the rock was formed, dating a or when it was last heated severely.

Each time laboratory maintains a physical realization of UTC, i.e. a clock (or a set of clocks) synchronized to UTC and of which the frequency is adjusted on the UTC frequency.

Alongside the 55 items in the Breguet group, Sir David’s collection includes a group of automaton clocks, as well as gold musical boxes adorned with enamel pictures, pearls and diamonds.