Verge and Foliot Clock Escapement: A Simple Dynamical System

• Autores: Mark Denny
• Localización: The Physics Teacher, ISSN 0031-921X, Vol. 48, Nº. 6, 2010, págs. 374-376
• Idioma: inglés
• Texto completo no disponible (Saber más ...)
• Resumen

  • The earliest mechanical clocks appeared in Europe in the 13th century. From about 1250 CE to 1670 CE, these simple clocks consisted of a weight suspended from a rope or chain that was wrapped around a horizontal axle. To tell time, the weight must fall with a slow uniform speed, but, under the action of gravity alone, such a suspended weight would accelerate. To prevent this acceleration, an escapement mechanismwas required. The best such escapement mechanism was called the verge and foliotescapement, and it was so successful that it lasted until about 1800 CE. These simple weightdriven clocks with verge and foliot escapements were accurate enough to mark the hours but not minutes or seconds. From 1670, significant improvements were made principally by introducing pendulums and the newly invented anchor escapement that justified the introduction of hands to mark minutes, and then seconds. By the end of the era of mechanical clocks, in the first half of the 20th century, these muchstudied and muchrefined machines were accurate to a millisecond a day.1