Identification guide
Seth Thomas clock dating
In Seth Thomas clock dating, the inked code can appear on the case back or bottom. Other Seth Thomas product periods use different markings.
Reverse the year, then read the month
Reverse 7981 to obtain 1897. A–L identify January–December, so D is April. The inked code can appear on the case back or bottom. A movement number or a patent date is separate from this case code.
Month-letter examples
| Code | Reading |
|---|---|
| 7981 A | January 1897 |
| 7981 D | April 1897 |
| 3091 L | December 1903 |
What to check next
Check that the mark actually has four reversed year digits and a month letter. Other Seth Thomas product periods use different markings. Record the movement stamp and case label to compare whether their dates fit together.