Three-quarter plate keyless going-barrel movement jewelled to the 3rd, with cap jewels on balance, lever and escape, the frame stamped ‘B’ and numbered 5110 by its yet unknown maker. Unusual double-roller detached lever escapement with double-height slotted roller with radial jewel, unusual machined lever with pallet jewels let into slots and club-tooth (divided lift) escape. Compensation balance, balance-spring with overcoil. 41 mm diameter.
Joseph Sewill, famous Liverpool chronometer and watch retailers, also with a London outlet, at 30 Cornhill, Royal Exchange, at this time. The London branch is known to have purchased from Kullberg and other top manufacturers, and the 5110 frame number does fit with Kullberg’s own serial number sequence at this period, but I do not believe this is Kullberg’s work.
NB: Only a few other examples of this caliper are known, mostly bearing the name Streeter, all having 4-digit 51** numbering. If anyone can identify the maker (B?), I would be pleased to hear from them. See also my letter on this escapement published in the NAWCC Bulletin, June 1995, page 379.
Lacking dial and hands, and all a bit dusty, but all appears to be in good, complete condition apart from a broken balance pivot. Not working