To identify a Seth Thomas mantel pendulum clock, determine the type of wood the clock is made of, analyze the clock’s movements, and check for a decoration on the hands of the dial’s face. Check the back, bottom or interior areas of the clock for remnants of a paper label.
Seth Thomas manufactured clocks using walnut veneer until around 1888. In the subsequent years, his company used walnut, oak and cherry, and by 1913, the firm started using mahogany and oak in the clock case as well. The clocks Thomas created prior to 1842 used wood movements, whereas the clocks he created thereafter showed brass movements.
In some clocks, the hands on the dial’s face displays an ornament that protrudes from the clock hand and looks like a tiny bird with wings and a tail. Clocks manufactured after 1875 featured an arrow with a circular bottom on their edges. Additionally, some clocks have a circle near the upper part of each hand.
Thomas also sometimes placed an image of his clock factory and added his name to the outer edge of the pendulum. Moreover, he typically etched his name, trademark and the clock’s patent on the metal plate. Search for this metal plate either inside the clock or on the bottom of it.