Image:Early Pendulum Clock Christian Huygens.jpg

The second pendulum clock built by Christiaan Huygens, inventor of the pendulum clock, around 1658. It is from his treatise Horologium Oscillatorium, published 1673, Paris, and it records improvements to the mechanism that Huygens had illustrated in the 1658 publication of his invention, titled Horologium. It is a weight driven clock (the weight chain is removed) with a verge escapement (K,L), with the pendulum (X) suspended on a cord (V). The large metal plate (T) in front of the pendulum cord is the first illustration of Huygens' 'cycloidal cheeks', an attempt to improve accuracy by forcing the pendulum to follow a cycloidal path, making its swing isochronous. Huygens claimed it achieved an accuracy of 10 seconds per day. Alterations to image: Cropped out the frame, caption. and figs. 2,3, and 4 which showed mechanical details of the clock.

Downloaded from European Clocks of the 17th and 18th Century, Metropolitan Museum of Art website on 2007-06-23. The caption identified it as Plate II from the 1724 Lyon edition of Christiaan Huygens's Opera Varia, vol. 1, and the same illustration that first appeared in Huygens's treatise on the pendulum clock, Horologium Oscillatorium sive de Motu Pendulorum ad Horologia Aptato Demonstations Geometricae, published in Paris in 1673.

1724

Christiaan Huygens

Public domain - author died in 1695