Friday, June 17, 2011 Pope Clement XI (1700-1721) ordered
Francesco Bianchini (1662-1729) to build a Meridian Line.
Bianchini was the Secretary of the Commission for the Calendar.
He chose the Basilica of Santa Maria degli Angeli because of the
stability of its roman walls and foundations and its suitable
dimension. The Line built by Giandomenico Cassini (1625-1712) in
1655 in San Petronio, Bologna, was the model for Bianchini, who
improved it by allowing the observation of stellar transits.
Pope Clement XI inaugurated the Great Sundial on October 6,
1702, the annual Feast of St. Bruno, founder of the Carthusian
Order, whose statue is in the entrance of the Church. Carthusian
monks ruled this Basilica for three centuries until 1884.
"ASTRONOMY IN THE CHURCH: THE CLEMENTINE SUNDIAL IN SANTA MARIA
DEGLI ANGELI, ROME" by Costantino Sigismondi