Chronograph
The word 'chronograph' (from Greek khronos + graphein, 'time-writer') was coined by Nicolas Mathieu Rieussec, who in 1821 demonstrated an inking timer for King Louis XVIII at the Champ de Mars horse races. The modern wrist chronograph dates to the 1910s.
Operating mechanisms
Three coupling systems dominate: lateral clutch (traditional, used by Lemania 1873/Omega 1861), vertical clutch (smoother engagement, used by Rolex 4130 and Patek CH 29-535) and the column-wheel vs. cam-actuated coordination of the start/stop/reset sequence.
Iconic calibres
Valjoux 72 (Rolex Daytona pre-1988, Heuer Carrera), Lemania 2310 / Omega 321 (Speedmaster Moonwatch through 1968 and again 2019–), Zenith El Primero 400 (1969, 36,000 vph), Rolex 4130 and Patek Philippe CH 29-535 PS.
Race for the automatic chronograph
In 1969 three projects independently produced an automatic chronograph: the Chronomatic Group (Heuer-Breitling-Hamilton-Buren, calibre 11), Zenith (El Primero) and Seiko (calibre 6139). Priority remains contested by horological historians.
Key facts
- ▸Term coined 1821 by Nicolas Rieussec
- ▸First automatic chronographs: 1969 (three competing projects)
- ▸Zenith El Primero remains one of few series 5 Hz (36,000 vph) chronographs