Santa Maria Novella
Detail #17

A view of Danti's armillary sphere showing both rings. The vertical ring lies in the meridian plane. The oblique ring lies in the plane of the equinox. The south facing facade of Santa Maria Novella was ideal for solar instruments, noon sunlight being accessible for much of the year.

Ref: J. L. Heilbron, "The Sun in the Church", Harvard University Press ( 1999) .