The Astronomical Clock of Jean Paulus (1710-1781) & Michel Ghiesbreght (1741-1827). An exceptional planetarium from the 18th-century Austrian Netherlands restored
In the eighteenth century it became fashionable to imitate and demonstrate the celestial movements in astronomical clocks or planetariums. However, a planetarium in which different world views were depicted, rotating simultaneously and driven by a clockwork, has hardly been made. A rare attempt to do so – namely the construction of an astronomical clock with both a Copernican planetarium and a planetarium according to the system of Martianus Cappella – was made in 1771 by Jean Paulus (1710-1781), a Jesuit from the Austrian Netherlands. This clergyman worked as a watchmaker at the Brussels court of Prince Charles of Lorraine, governor-general of the Austrian Netherlands. After Paulus’s death, this exceptional astronomical gearwork came into the hand of the mathematician Michel Ghiesbreght (1741-1827), who pretended to be the inventor of this astronomical clock and used the instrument to raise his own status and further his academic career. The instrument later fell into disrepair and after all kinds of wanderings it ended up in the collection of planetarium Zuylenburgh, in Oud Zuilen, a few years ago. The instrument is recently restored to its former functionality by the skilled hands of clock restorer Pieter de Ruiter, who has been able to reconstruct missing parts thanks to the surviving original construction drawings.