Clock escapement
Brocot (visible) deadbeat escapement
VerifiedA deadbeat-type escapement in which the pallets are jewelled and mounted visibly at the dial centre, behind pierced apertures, so the escapement's action can be watched; functionally it behaves as a standard deadbeat escapement.
Schematic arrangement
How it is laid out
Outline schematic only, drawn to show the characteristic arrangement of wheel, locking member and oscillator. It is not a dimensioned working drawing and should not be used for setting up or repairing a movement.
Advantages
- Combines deadbeat accuracy with a visible display
- Readily serviced from the front of the movement
Drawbacks
- No functional advantage over a concealed deadbeat escapement beyond display
Attribution and period
Mid-nineteenth century, associated with the Parisian maker Achille Brocot
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
- Jewelled (usually cornelian or agate) semicircular pallets visible through apertures at the dial centre.
- Escapement mounted on the front plate, behind the dial, rather than at the back.
- Typical of Parisian drum and mantel movements of the second half of the nineteenth century.
Servicing and conservation
The exposed jewelled pallets chip if the clock is knocked or if the hands are forced. They can be rotated in their settings to present an unworn face, but this must be done with the depthing checked afterwards.
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
- Britten, F. J., Old Clocks and Watches and Their Makers
- Gazeley, W. J., Clock and Watch Escapements