Astronomical clock of Saint-Omer

About

The astronomical clock of Saint-Omer is a medieval clock in the Cathedral of Notre-Dame de Saint-Omer. Beautiful and unique medieval astronomical clock dating back to 1378 and still in operation. In 1555 the canons entrusted Pierre Enguerran, a Aodomarian watchmaker, with the task of "making and building a clock by putting to his advantage the recovery of the ancient".

The needle bearing the sun indicates the hour, the month, the calendar of the day and the sign of the zodiac. It is also an astrolabe clock that gives us the continuous place of 8 constellations. It is also an astrological clock with zodiac signs, their calendar and the 12 houses.

All this with a mechanical, multi-secular, composed only of 25 moving pieces for a clock that sounds 1⁄4, 1⁄2 and hours on 3 different bells including one from 1618 melted in Saint-Omer. Given all the indications and the few moving parts, this clock is unique in Europe. It only drifts 30 seconds a week.

In order to properly set this clock, a very large sundial was executed in 1610, bearing the zodiac signs. Calculations...