p - toc - n

Slide 17: American Calendar Watch Co. Movements

  • These movements were re-engraved and re-gilded.
  • The movements appear to be an Appleton Tracy grade with serial number after 193000 if we assume the movements had to be made post 1865 with the patent date of February 13, 1866. The high end is probably 253000 (late 1866).
  • Specific details: 1) the layout of the four-pillar top plate appears identical to a Model 57, screw for screw; 2) the arm on the expansion balance is post 1860; 3) the top plate has real jewel settings which are on only ATCo grade M57s; 4) the top plate has screw adjustable banking pins which were introduced around S/N 40,000 (1861); 5) the top plate has an applied index versus on the balance bridge for higher S/Ns, approximately 300,000 (1867); 6) the movements have a stop works barrel; and 7) the 3rd wheel plate jewel is approximately 4mm, which defines the upper S/N range according to my data tables.
  • A sub-assembly number "78" (Joe's)/"82" (Michael's) is stamped on the underside of the balance bridge and top plate. If we assume both movements came from the same batch, I count 31 possibilities from the S/N Ledger in the above range where the S/Ns can end in 78 & 82 and have expansion balance.