Equinoctial dials
Two examples of a rare form of equinoctial dial that tells the date as well as the time. The time is given by the shadow of the diameter of the semicircle on the hour disc, the date by the shadow of the disc on the diameter.
Two examples of a rare form of equinoctial dial that tells the date as well as the time. The time is given by the shadow of the diameter of the semicircle on the hour disc, the date by the shadow of the disc on the diameter.