The earliest surviving pendulum clock dates from 1657 but it is probable that the prototype was made a year earlier. Coster secured the exclusive rights to build such clocks for 21 years but died suddenly two years later. Reijnaert, however, remained in the workshop until 1669, when he set up his own business.
One of his clocks from this period is coming up for sale at Dr Crott in Frankfurt in the auction on November 15-16. The 17in (44cm) high, hour-striking Pendule Religieuse with a silvered dial in an ebonised case incorporates many of the elements of his teacher’s timekeepers and has a guide of €30,000-35,000.