p - toc - n

Slide 14: Identifying Unmarked Movement

  • This particular movements has no markings, not even serial number. Usually you will at least see serial number. In this example I was fortunate to also see the pillar plate under dial.
  • Important clues: sprung under hairspring, hidden stud, steel balance, engraved index, brass wind guard cup, 1st series click & oblong ratchet bridge, top plate does not encircle barrel, sub-assembly serial number 92 on pillar plate.
  • Answer: J. Watson grade around serial number 23,000-28,000. However, it likely is exactly 25392 because the S/N Ledger lists this movement in batch of 10 as "Nameless Ordered Mvt" with steel balance. First run Watson is 23601-24300; the next run is over S/N 28000 when the 1st series click was replaced with the circular click.
  • Would have thought this movement was a P.S. Bartlett because there are so few Watsons; however, it can't be a PSB with engraved index.
  • The published monograph has this wrong (sorry).