A sundial is a timepiece, whereon a gnomon casts a shadow on a graduated surface; the position of the shadow shows the time of day. There are many types of sundials; the exact form must be specified in the blazon. The illustration shows a cylindrical sundial, also called a “shepherd’s dial”; the artifact was known and used from ancient Rome to Elizabethan England [Hester Higton, Sundials: An Illustrated History of Portable Dials, 2001, pp.13-18]. No form of sundial has been found in period armory.
For related charges, see quadrant. See also astrolabe, clock, equatorium, sphere.
Manus le Dragonier bears as a badge: A cylindrical sundial argent.