This article describes the magnificent 21-foot high Glamis Castle sundial in Scotland, tentatively dated around 1683. It is an elaborate obelisk dial featuring 84 time-recording faces, lion dials for cardinal points, and a complex \pineapple\ (stellar rhombicuboctahedron) with numerous declining and reclining faces. The article also discusses its Equation of Time inscription and possible mathematical contributions by James Gregory.
Dials: Multi Faced,
Mathematics of Dialling,
Sundial Design & Layout,
Equation of Time,
Historical Dials