Seth Thomas “Sussex” Adamantine Mantel Clock

I’ve always liked the appearance  of these green and black Seth Thomas Adamantine mantel clocks, and this one is interesting in having the model name “Sussex” stenciled on the back. This clock has the 8-day movement with escapement in back, so it was made in 1901 or earlier. The case is 11 3/4 inches tall and 11 3/4 inches wide at the feet. The minute hand is 2 3/16 inches long.

Sold 3-3-02 E is written on the back of the clock, meaning that it was sold March 3, 1902.

See more photos.

Repair job 5855. New time click rivet, polished the pivots, installed 9 bushings, true the escape wheel teeth. The back escapement movement uses a strip recoil escapement requiring a small pendulum arc. The pendulum arc when running is much larger than the minimum arc (escape arc), so these clocks are very reliable even when slightly off-level. These movements have fairly thick mainsprings (around 0.018 inch) that are 11/16 inch wide rather than the standard 3/4 inch wide. If a mainspring does need replacing (it is best to keep the original springs) it is important to not use a spring that is too strong.

This example’s original mainsprings are the following sizes:

Time: 11/16 by 0.0175 inch

Strike: 11/16 by 0.018 inch.

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  1. I’ve seen this a few times, where the model name is stamped on the bottom of the clock near the date. I can’t explain why they wrote the model name on only a few clocks in this way.


  2. So I bought this clock at antique shop in California twenty years ago. It is a Seth Thomas 1909 Sussex, Green and black, paper dial, Width in accordance, Height slightly different. !0 and 3/4
    Two and 3/16 minute hand but what I find interesting is that Sussex is written on the bottom of clock upside down from the 1909. What is really strange is I am wondering, Did Seth Thomas ever hand sign a clock? Like on the label on the bottom back? There’s a signature there and it looks suspiciously like a Seth Thomas signature. Everything is definetly Seth Thomas. Stamped everywhere its suppose to be. No, it’s not a fake. But I sure am curious? Do you think it’s possible?
    Thanks, Judith Scott

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