Audience clock by Antide Janvier from c.1800, estimate €32,000-40,000 at Dr Crott in Mannheim on November 7.

Enjoy unlimited access: just £1 for 12 weeks

Subscribe now

He sold several extravagant timepieces to the French royal family, who rewarded him with the title of Clockmaker to the King.

Among his other specialities were so-called audience clocks, an example of which, from c.1800, is being offered by Dr Crott in Mannheim on November 7. The mahogany case with two gilt bronze sphinxes is a reflection of the then current passion for Egyptian decorative motifs.

As the name implies, these clocks were designed to denote the time – in this case 10 minutes – allowed to a supplicant to bring forth his petition. The 10 minutes are marked on a small subsidiary dial, while the main chapter ring indicates 24 hours.

True to his fascination for all things astronomical, Janvier also incorporated a refined system for showing the age of the moon, on a small central disc, and the moon phases, which are demonstrated via a small rotating moon, fitted into the hour hand.

The guide is €32,000-40,000.