Replica of wooden beam clock. The original is from 1640. One hand indicates the time. Roman numerals These kinds of movements have no pendulum for the drive but a beam at the top of the clock that moves back and forth, also called a foliot pendulum. The mechanism is used since the 14th C. The mechanism drives a horizontal beam with weights that then starts moving back and forth. Weights on the beam also determine the speed of the movement and therefore also the speed of the hands. The speed is regulated by sliding the wooden blocks on the beam in or out. These clocks were originally used when minutes and seconds were not important. Until late in the 17th C, clocks had just one hand to indicate the hours. The so-called small hand. This type of clocks was often used in monasteries.