September 2021
Page 2

Islamic Sundials Signed by al-Mansur Carrying Dates in the Late 17th Century: An Examination of their Gnomonic and Historical Anomalies

Examines ten mosque sundials signed by al-Mansur and dated 1671–1681 AD. These instruments feature epigraphic anomalies and non-functional gnomonic layouts, including inaccurate hour lines and prayer indications. The authors conclude these sophisticated yet flawed dials are likely modern ‘fakes’.
Dials: Horizontal, Mathematics of Dialling, Historical Dials

Fathi Jarray
Eric Mercier
Denis Savoie