Inside the south transept of the cathedral stands one of the most complex mechanical clocks ever built. Constructed between 1865 and 1868 by Auguste-Lucien Vérité, a clockmaker from Beauvais, it has 52 dials, around 90,000 individual parts, and tracks an extraordinary range of astronomical and civil phenomena: solar and lunar time, the movements of the planets, tidal predictions, the liturgical calendar, and the time in 18 cities around the world.
The clock is housed in a Gothic revival case that fills an entire bay of the transept. When it strikes the hours, a sequence of 68 automaton figures performs a procession representing the Last Judgement. Demonstrations are held at set times each afternoon — check with the cathedral for the current schedule. The ticket for the clock demonstration is sold separately from (free) entry to the cathedral itself.
The clock is notable not just for its technical complexity but for the ambition it shares with the building that houses it: Beauvais seems to attract projects that aim to be the biggest or most complex thing of their kind.