How to Level Mantle Clocks

Use a bubble level to measure the clock's resting place alignment. If the location is out of level, determine whether it can be corrected. Alternatively move the clock to a level location that is vibration free from heavy foot traffic and slamming doors that can bring it out of alignment. Before relocating it, carefully remove its pendulum to prevent internal damage.

Use a bubble level to measure the left-to-right alignment of the mantle clock as it sits on its resting place. The left-to-right alignment affects the beat of the clock and is thus critical for it to keep the correct time.

If the clock is uneven, use a small shim such as a matchbook cover, a washer or a quarter under the low section of your clock to raise it to a level position. Remeasure with the bubble level to ensure that your shim has corrected the unevenness.

You can also adjust the left-to-right level by gently bending its "verge," also known as a "crutch" in the direction that is low. The verge is the part that the top of the pendulum fits into. It affects the movement of the "escapement" which makes the tic-toc sound.

Use a bubble level to measure the front-to-back alignment of the mantle clock as it sits on its resting place. This alignment is important in preventing the pendulum from resting on the clock's bell or its back wall. Shim any unevenness as before.