Large silver watch with experimental escapement by unknown maker, England, hallmarked for 1792. Silver case. White enamel dial with subsidiary seconds dial. Steel hands. Movement with unusual variety of Robin escapement. On the balance-staff are the two usual pallets, one for receiving impulse and one for engaging the fork of a lever for locking the escape-wheel. However, locking is not achieved by the usual anchor but by a steel cylinder integral with the lever arbor. On the 'dead' beat, an escape-wheel tooth moves only from the outside to the inside of the cylinder. Compensation curb of two straight and parallel bi-metallic strips with a very fine adjustment.

The watch formed part of the collection of the Rev. Henry Nelthropp, who purchased it from Brockbank & Atkins, who had owned it for most of its life. Clockmakers' Museum No. 522.