It is built on a new and scientific plan, embodying a free pendulum. In this type of dock the pendulum is untouched by the driving mechanism, and receives its impulse through the suspension spring. The pendulum rod is of invar, an alloy which is practically unaffected by temperature changes. The bob is of steel, countersunk to the center with a short steel sleeve to make the necessary slight adjustments for temperature.
The dial is arranged like and read the same as the dial on a ReiBer Observatory clock. All the parts were made by Mr. Takano, including the wheels and pinions and the dead beat escapement.