This article discusses the Benares Sundial, one of five equatorial sundial observatories built in India by astronomer prince Sawai Jai Singh II in the 18th century to rectify astrological errors. The authors also describe their work with stereoscopic images and an autocyclostereoscope for viewing 3D images without special glasses, including a 1902 stereograph of the Benares sundial.
Dials: Equatorial,
How Sundials Work,
Historical Dials