Verge (crown-wheel) escapement

Attribution and period

c. 1300 in clocks; adapted to watches by the sixteenth century

Horological firsts are frequently contested. Where an invention is attributed to a named maker, that attribution is recorded as such rather than treated as settled fact.

How to recognise it

• A horizontally mounted crown (escape) wheel whose teeth stand up out of its plane, engaging a vertical staff.
• A balance without a hairspring on the earliest watches; later verges have a spiral spring but still no lever or pallet fork.
• Almost always found with a fusee and, on English work, a pierced and engraved balance cock.

Servicing and conservation

Verge movements wear at the verge pivots, crown-wheel teeth and potence. Because the arrangement depends on friction, a worn verge cannot be corrected by cleaning alone and rebushing or pivot work is skilled bench work. Leave it to a watchmaker experienced in pre-lever work; do not attempt to convert a verge to a lever, which destroys the object's historical value.

Work on an antique escapement by a qualified watchmaker or clockmaker. Conservation of original parts is preferred to replacement wherever the object will still run.

Bibliography

• Gazeley, W. J., Clock and Watch Escapements
• Britten, F. J., Old Clocks and Watches and Their Makers