Cylinder Escapement
Also known as: Horizontal escapement
Record status
Individual type · partial
Period
1695 onwards
The cylinder, or horizontal, escapement is a watch escapement in which a cut-away cylinder on the balance wheel's shaft takes the place of pallets. Its chief attraction was that it is much thinner than the verge escapement, so watches could be made fashionably slim.
The escape wheel, which usually has 15 wedge-shaped teeth, feeds its teeth into the cylinder one at a time. Each tooth gives the balance an impulse by pressing on the cylinder's edge as it enters, is held inside while the balance turns, and gives a second impulse as it leaves on the other side; the balance is impulsed over an angle of 20 to 40 degrees in each direction. Because a tooth stays in contact with the cylinder throughout the balance's cycle, the cylinder is a frictional rest escapement rather than a detached one. It was therefore less accurate than detached escapements such as the lever, and its high friction caused wear that called for more frequent cleaning.
Evidence at a glance
- Linked sources
- 1
- Photograph views
- 1
- Catalogue references
- 0
Counts describe this entry’s documentation, not authenticity, rarity or completeness. Photographs may show one specimen; check each caption and licence.
Historical context
Invented by Thomas Tompion in 1695 and perfected by George Graham in 1726, the cylinder was one of the escapements that replaced the verge in pocket watches after 1700. Wear kept it out of general eighteenth-century use apart from a few high-end watches with ruby cylinders, until French makers made the cylinder and escape wheel of hardened steel. From the mid-nineteenth to the twentieth century it was used in large numbers in inexpensive French and Swiss pocket watches and small clocks.
Technical characteristics
- Type
- Frictional rest escapement
- Impulse
- Twice per tooth: on entering and on leaving the cylinder
- Escape wheel
- Usually 15 wedge-shaped teeth
- Impulse angle
- 20 to 40 degrees each direction
Identification
- Source note
- Background drawn from Wikipedia (“Escapement”), a tertiary source; details have not yet been checked against a standard horological reference.
- Identification
- Cut-away cylinder on the balance shaft; wedge-shaped escape wheel teeth; no lever or fork
- How to identify
- Look at the balance: a cylinder escapement has a hollow, partly cut-away cylinder on the balance shaft and no separate lever or fork between the escape wheel and the balance. The escape wheel teeth are wedge-shaped and enter the cylinder one at a time.
Catalogue references
No catalogue numbers recorded. Numbers are only published once transcribed from a verified edition of a standard catalogue — they are never inferred.
Research required
- Dated maker-signed cylinder watches from institutional collections still to be linked as examples.