Mystery clocks have been popular since the 18th century. The clock seems to have no mechanism but keeps time.

Instead, through a series of mechanisms that are designed to alter the pendulum’s swing as little as possible, it sends an electrical signal every 30 seconds and kicks the slave clock which is ...

Like London’s Big Ben, the clock’s escapement — the device that converts the force from a weight in the timepiece to its counting mechanism — uses gravity to keep its pendulum swinging.

A quick hall effect sensor to detect the pendulum passing made it into a proper clock. Considering it’s a printed plastic clock, losing only 2-3 seconds per day is incredibly good.

Nestled in a nearly 160 foot tower, the clock is the second largest model to be made by E. Howard & Co., and its pendulum descends 14 feet beneath the mechanism itself. The bottom of the pendulum ...

Clocks have been made in forms that depend on the size and shape of the clock's mechanism. The 18th-century tall case, or grandfather, clock was made to hold a long pendulum.

Thus early clock mechanism must have featured a bell but possibly not a dial.” An important milestone in the development of clocks was the pendulum.