Seller: ukr10 (727) 96.6%, Location: Clearwater Beach, Florida, Ships to: Worldwide, Item: 181846513083 Condition: The clock is in working condition, although we have not verified it recently. Should be calibrated and lubricated by clock master, Country/Region of Manufacture: France, Details: Antique pendulum clock by Leon Fleuret Gracey, France, circa 1800 Material: brass, color enamel, etc. The clock is in working condition, although we have not verified it recently;Every hour there is a bell sound Should be calibrated and lubricated by clock master. There are 2 very heavy weights, which is supposed to be attached to 2 cords, coming down from the clock. The winding key is available as well. It means that the power comes from 2 sources: 2 weights and spiral spring. Height: approximately 5 feet or 150 cm; Total weigh is approximately 30 lb. Most heavy parts are white weights.Provenance: Estate sales in Florida, USA. Pendulum clock The next development in accuracy occurred after 1656 with the invention of the pendulum clock. Galileo had the idea to use a swinging bob to regulate the motion of a time-telling device earlier in the 17th century. Christiaan Huygens, however, is usually credited as the inventor. He determined the mathematical formula that related pendulum length to time (99.38 cm or 39.13 inches for the one second movement) and had the first pendulum-driven clock made. The first model clock was built in 1657 in the Hague, but it was in England that the idea was taken up. The longcase clock (also known as the grandfather clock) was created to house the pendulum and works by the English clockmaker William Clement in 1670 or 1671. It was also at this time that clock cases began to be made of wood and clock faces to utilize enamel as well as hand-painted ceramics. In 1670, William Clement created the anchor escapement, an improvement over Huygens' crown escapement. Clement also introduced the pendulum suspension spring in 1671. The concentric minute hand was added to the clock by Daniel Quare, a London clock-maker and others, and the Second Hand was first introduced. In mechanical clocks, the power source is typically either a weight suspended from a cord or chain wrapped around a pulley, sprocket or drum; or a spiral spring called a mainspring. Mechanical clocks must be wound periodically, usually by turning a knob or key or by pulling on the free end of the chain, to store energy in the weight or spring to keep the clock running.