Periode: 1665 - 1675

Afmetingen: H: 29,0 cm B: 24,0 cm D: 13,0 cm

Inventarisnummer: V09854

Rumour has it that this clock was bought by Christiaan Huygens when he was working in Paris in the 1670’s. The clock was built by the Paris clockmaker Isaac Thuret, probably following Huygens’ instructions. It has an extraordinarily long pendulum, which enables great accuracy. The length of the pendulum – approximately one meter – also causes it to pass through the middle of the swing movement every second.

This was useful as the clock was designed as an astronomical time keeping device. As the clock ticked every second, Huygens did not need to divert his eyes from his telescope to mark the time during astronomical observations. This type of clock is called a ‘regulateur’. The face of the clock has three dials: a large one with a minute hand, and two smaller ones for the hours (below) and the seconds (top).

After Huygens’ return to the United Provinces the clock came in the possession of the Leiden University Observatory, somewhere around 1682. There it was highly appreciated. In 1754, almost ninety years after it was made, the Leiden professor Johan Lulofs used it with his observations of the planet Mercury, and he praised the clock for his accuracy, ‘highly preferring it above any newer [clock]’.

A.C. van Helden, Rob H. van Gent, De Huygens collectie, Leiden 1995, pp.14,15
Hans Hooijmaijers, Telling Time, Leiden 2005, pp.30,31