The mechanical clock, invented in the 13th century, chimes the hours thanks to a weight falling that sets a series of gears in motion. From the 14th century onwards, the folio escapement gave this fall a regularity that is contrary to natural physical laws by providing controlled measured increments. The displayed time is then divided into 12 equal hours, unlike the sun, the shadow of which cast on a dial results in uneven hours that vary with the seasons.
Few gothic clocks are still preserved today. In this example, a ringing device animates the façade's mask; the folio was replaced late on by a carved wheel.