Санта-Мария-дельи-Анджели-э-деи-Мартири
As part of his efforts to improve the accuracy of the calendar, Bianchini was commissioned by Clement XI to construct an important meridian line in the Basilica of Santa Maria degli Angeli e dei Martiri (the Basilica of Saint Mary of the Angels and the Martyrs) in Rome, a device for calculating the position of the sun and stars.