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.
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.