Encyclopedia

Movements, mechanisms & components

Each entry explains how a mechanism works, why it was invented, who is credited, and where it appears in the catalogue.

Escapements

Verge escapement

c. late 13th century

Anchor (recoil) escapement

c. 1657–1670

Detached lever escapement

c. 1755

Spring detent escapement

late 18th century

Grasshopper escapement

c. 1722

Co-axial escapement

1970s

Foliot

c. 14th century

Balance spring (hairspring)

1675

Fusee

15th century

Tourbillon

Patented 1801

Minute repeater

18th century

Chronograph

1816 (Louis Moinet); 1821 (Nicolas Rieussec)

Flyback chronograph

Early 20th century

Valjoux 7750ETA 2824-2Seiko calibre 35A

	Valjoux 7750	ETA 2824-2	Seiko calibre 35A
Type	Automatic chronograph	Automatic	Quartz
Period	1974–present	1971 (2824), 2824-2 later revision	1969
Country	Switzerland	Switzerland	Japan
Diameter	30 mm (13¼ lignes)	25.6 mm (11½ lignes)	Undocumented here
Jewels	25	25	Undocumented here
Frequency	28,800 vph (4 Hz)	28,800 vph (4 Hz)	8,192 Hz crystal
Power reserve	c. 42–48 hours	c. 38 hours	Battery, c. 1 year
Complications	Cam-actuated chronograph, day-date	Date	None
Status	Documented	Documented	Documented