Nº 013
oculus
A circular opening at the crown of a dome that turns sunlight into a moving dial.
Latin for eye: a round opening at the apex of a dome that lightens the structural crown, vents warm air, and casts a sharp beam of sunlight across the interior.
The film, in words
The largest unreinforced concrete dome in the world has a nine-metre hole right at the top.
It's called an oculus, Latin for eye: an open ring of brick and bronze at the crown of a dome.
Leaving the centre open removes weight where the dome is weakest, while a compression ring locks the arch in place.
A sharp beam of sunlight sweeps across the coffers like a giant sundial, and rain drains through tiny holes in the floor.
In Rome's Pantheon, built around 125 AD, the oculus is the only window in the entire rotunda.
Its cousins: the compluvium in Pompeii, the dome lantern in Florence, and the chahar taq in Iran.
Oculus. A circular opening at the crown of a dome that turns sunlight into a moving dial.
Cousins
- compluvium Pompeii
- lantern Florence
- chahar taq Iran