"In the 18th-century, Pope Clement XI decided to create an official reference point for telling time in Rome. He commissioned astronomer Francesco Bianchini to build a meridian inside Michelangelo's Basilica of St. Mary of the Angels and Martyrs.""High noon: How the sun and moon guided prayer times and liturgy". Catholic News. 5 August 2011. Archived from the original on 10 August 2011. Retrieved 16 June 2013.
Moore, P. (1985). "The Mapping of Venus: Presidential Address, 1984". Journal of the British Astronomical Association. 95: 50. Bibcode:1985JBAA...95...50M.
"In the 18th-century, Pope Clement XI decided to create an official reference point for telling time in Rome. He commissioned astronomer Francesco Bianchini to build a meridian inside Michelangelo's Basilica of St. Mary of the Angels and Martyrs.""High noon: How the sun and moon guided prayer times and liturgy". Catholic News. 5 August 2011. Archived from the original on 10 August 2011. Retrieved 16 June 2013.