San Petronio Basilica

The Basilica of San Petronio is the main church of Bologna, the old città d’arte in the Emilia Romagna region of Italy. The church hosts also a sundial in the form of a meridian line inlaid in the paving of the left aisle in 1655; it was calculated and designed by the famous astronomer Giovanni Domenico Cassini, who was teaching astronomy at the University: at 66.8 meters it is the longest sundial in the world, following measurements that were for the time uniquely precise.

The video below shows the passage of the sun on the Cassini’s meridian line inside San Petronio in Bologna on the 30th November 2007. Thanks to matutianu1935 of YouTube-

Leave a comment

You must be logged in to post a comment.