Seth Thomas Adamantine Mantel Clock, Arno, Black with Green Trim

Here’s a beautiful little Seth Thomas Adamantine mantel clock, named “Arno”, that I repaired. The clock is 11 1/2 inches tall and 12 1/2 inches wide. The minute hand is 2 1/8 inches long. The pretty case is finished in black Adamantine (colored celluloid veneer) with green top, pillars and pillar blocks.

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Repair job 7771. I polished the pivots and installed bushings. I secured one regulator gear with Locktite and tightened the click rivets. The original adjustable pendulum bob weighs 5.4 ounces.

I replaced the original 3/4 x 0.0179 inch time mainspring with a Merritt’s MS310 3/4 x 0.016 x 108 inches to reduce future wear to the time mainwheel teeth. I removed and cleaned the case ornaments and polished the Adamantine.

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One comment

  1. Bill, the clock looks great. I have an Arno as well, with an “89” movement and this is very similar to mine except my columns are the beige color.

    Question for you. What is the difference between the Arno and the Adele? I can’t find any definitive differences between the two. Also looking at pictures of both, I see some having a face that has the regulator above the “twelve”, which would mean it is not a “89” movement, but earlier than c1900. Everything I ‘ve seen in Tran Duy Ly book leaves me with the impression that the Arno is 1904, and the Adele is 1904-1910, and shows the regulator below the center.

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