December 2020
Page 19

The Significance of the Declination Arcs on a British Museum Sundial

This article follows Ortwin Feustel’s analysis of the British Museum sundial (1884,0615.1) to determine the meaning of its declination arcs. By calculating the corresponding solar declinations, the author correlates them with agriculturally significant events recorded in the ancient Egyptian Geminos parapegma, such as the rising of Sirius and the setting/rising of the Pleiades.
Dials: Equatorial, Historical Dials, How Sundials Work, Mathematics of Dialling

Geoffrey Thurston