81. Auktion - Auktionen Dr. Crott

A very fine, rare precision hunting case pocket watch with Potter’s
patented pivoted detent chronometer escapement
Case: 18k gold, tiered, smooth, signed, punched, à goutte, glazed
movement, 5-piece hinges. Dial: enamel, radial Roman numerals, sunk
seconds, signed, blued Breguet hands. Movm.: specially designed bridge
movement, nickel-plated, “fausses côtes” decoration, gold chatoned,
polished screws, pivoted detent chronometer escapement, heavy compensation
blance with gold and platinum screws, freesprung, blued, helical
balance spring, ruby endstone on balance, chronometer wheel and pivoted
escapement.
Albert H. Potter pivoted detent chronometer
The present watch is an excellent example of the very highly finished
pivoted detent chronometer calibre created by Albert H. Potter; Potter
was and remains probably the most celebrated American maker of pocket
chronometers. In the latter part of his life he worked in Geneva, where he
was able to find accomplished craftsmen to work with him. This watch
features a number of peculiarities which are typical for the work of Albert
Potter. It has his patented safety barrel (patent No. 168581) to protect
the going train from the effects of mainspring breakage; it uses a considerable
amount of height, which means that the spring is unusually narrow
for such a large watch. The pivoted detent escapement has Potter’s
own design of pivoted detent with a special arrangement for the spring
intended to make the passing action as smooth as possible; a circular
counterpoising tail is carried on a piece at right angles to the blade near
the free-end of the detent. A single pin set in the end of the escape wheel
cock provides banking for the detent. Therefore no adjustment for the
depth of locking is needed. This arrangement of the passing spring on an
outrigger on the end of the detent was used earlier by James Ferguson
Cole. The elegant plate design of this calibre allows for easy setting of
the train and was patented on April 5, 1887. The mechanism for winding
and setting is unique for Potter, although he did not patent this particular
design: its intermediate setting wheel moves vertically for engagement,
the click pin protruding by the barrel affords an easy and secure means
of letting the spring off, and Potter’s typical glazed cuvette allows
the movement to be seen. There are very small discrepancies between
Potter’s early chronometers and the later ones; early ones have spotted
movements while the later ones are usually decorated with Geneva stripes
and were almost always stamped with Potter’s large trademark, unlike
the early ones. Kalish mentions that Potter used to say he had no need
to stamp his cases, since everyone recognized his work anyway. Early
pieces have a traditional balance spring stud, the later ones are far more
elegant. This watch uses several of Potter’s patents and has their details
engraved on the bridges. The plate design was patented on January 4,
1876 (American patent No. 8888), the escapement (patent No. 168582),
the motor barrel (patent No. 168581) and the balance (patent
No. 168583), on October 11, 1875. The same inventions were patented six
weeks earlier in England under patent No. 2985 of Aug 25, 1875. Albert
Potter’s work is not only rare but also always of the highest quality and
with completely original designs.
30504 G/C: 2 Z/D: 2 W/M: 2, 41, 51
30.000 - 40.000 EUR 39.900 - 53.200 USD