The most important Breguet inventions and innovations since 1775
Development of the perpétuelle, or automatic watch. Invention of
the gong spring for the minute repeater. Design of the famous
Breguet hands and numerals. The Breguet dial, engine-turned by
hand. The ratchet key known as the "Breguet Key". Escapement
working without oil. Invention of the pare-chute (timepiece
shock absorbers). Development and production of the mechanism
for the Chappe optical telegraph. First description of the
sympatique clocks. Development of the perpetual date calendar.
The Breguet balance-spring. The ruby cylinder. The single-hand
watch known as the "subscription watch". Patent of the constant
force escapement (March 9) Invention of the musical chronometer,
the clockwork mechanism that acts as a metronome. The "tact"
watch. Patent of the Tourbillon Regulator (June 26). Development
and production of the first wristwatch, ordered by the Queen of
Naples. Appearance of dials with off-centred hour ring. Fine-
tuning of the double-