Skip to content

We're on vacation from 12/22 — 1/4. Shipping will resume on 1/5.

Early 20th Century Comptometer Signet Ring


This gold family crest-style signet ring would have been awarded to students who performed exceptionally well while learning to use the Comptometer. This machine, made from 1887 to the mid-1970s, was the first push-button calculator. It could perform addition, subtraction, multiplication and division. Because each key depression accumulated the total, an operator could press multiple keys at the same time making it an extremely fast machine. Men at the factory who proved most talented at comptometing(?) received enameled tie pins and women got these + % X - rings so there would be no confusion over who was the biggest nerd in the room. Made by Ostby & Barton, an American jewelry manufacturer with fascinating ties to the Titanic (Ostby was an unlucky passenger).


  • Materials

    10k gold (tests), enamel

  • Age

    c. 1920

  • Condition

    Good - surface wear commensurate with age and use; some loss to the enamel

  • Size

    5.25, can be resized; 9.8mm head, 2.4mm shank

Need more photos?

Send us an email to request photos of this piece on a model.

please note:Terms of Sale

Antiques can be returned unworn and in original condition within 10 days of delivery for an exchange or refund minus the cost of shipping. Once a piece has been altered, including ring re-sizing, it is FINAL SALE.