The clock was built and operational by 1855. It was constructed by Brother Bernardin (1812−1876) of the Community of Brothers of The Mother House of the Brothers of Ploërmel. The clock was originally inside the monastic building, it is now displayed in a glazed kiosk in the interior court of the cloisters.[2]
It comprises an astronomical clock and an
orrery displaying all the planets known at that time. The Earth is especially well represented with its correct inclination and the moon encircling it
Astronomical clock
Ploërmel Astronomical Clock
The clock has ten dials which show:
Dial 1. Solar time
Dial 2. Calendar
Dial 3. Position of the Moon, the months of the year, seasons and signs of the
zodiac
Dial 4. The
equation of time (the difference between mean time and real time)
Dials 5 and 6. The standard time to the nearest minute for the whole world.
Dial 7. The position of the Moon, Earth and Sun.
Dials 8 and 9. The view of the heavens over Ploërmel.
Dial 10. The position of the Sun on the
ecliptic, and the centuries. The small black hand rotates once every 1000 years.[3]
Orrery
The
Orrery displays the
Sun,
Mercury,
Venus,
Earth,
Mars,
Jupiter,
Saturn and
Uranus, together with the
Moon, the four satellites of Jupiter and the six satellites of Saturn. It was constructed around the time of the discovery of Neptune, and before Pluto, and these two planets are not shown.