This Adamantine mantel clock with black slate and tan marble appearance has the date code 3981F (June 1893) on the bottom. The case is 10 3/16 inches tall and 16 1/2 inches wide at the feet. The paper dial has a 4 1/4 inch minute track, and the minute hand is 2 1/8 inches long.
The movement is the “hip” style with rear recoil escapement. (This movement was used in Adamantine clocks until replaced by the No. 89 movement in 1901.
Repair job 5979. I polished pivots and installed 5 bushings. The mainsprings were too wide so I replaced them. The mainsprings I used are CML 175.3 from Mile High Clock Supplies. The dimensions are 11/16 inch wide by 0.0168 inch thick by 96 inches long.
The pendulum bob is 1 1/8 inches diameter and weighs 2.4 ounces. It is old and may or may not be original.