How to Adjust the Pendulum of a Seth Thomas Mantle Clock

Seth Thomas was the longest operating clock manufacturer in the U.S., operating for nearly 200 years. The Seth Thomas Company produced a number of different mantel clocks powered by pendulums. Unlike grandfather clocks, mantle clocks have pendulums on the back of the clock and not the front. If you tip or move the mantel clock without taking out the pendulum first, the pendulum inside will need adjustment to run properly.

Instructions

1. • 1

     Turn around the Seth Thomas mantel clock and open the pendulum door. The door will swing open when you undo the latch.

   • 2

     Remove the pendulum from the rod carefully.

   • 3

     Make sure the rod is not misplaced. It should be located right behind the movement and it should move easily from side to side.

   • 4

     Slide the pendulum back onto the hook at the bottom of the rod.

   • 5

     Push the pendulum to start it swinging.