2.1

Antique Sundials

The oldest known sundials have a gnomon (shadow hand), a vertical rod. Even the ancient Egypt obelisks are nothing more and nothing less than huge gnomons.

The scaphe has been known since the 3rd century BC. It is a sundial consisting of a hemispherical bowl, with the gnomon located vertically at the lowest point of the bowl. The shadow of its tip indicates the course of the sun on the concave surface. It shows the position of the sun from sunrise to sunset.

In a simplified version, the concave area was reduced to the section which was really needed to read the position of the sun in the course of the year. Additionally, the gnomon was placed horizontally, so the course of its shadow approximately corresponds to the scale marks, which facilitates the reading of the scaphe.

It becomes visible that the sun moves across the sky on a lower path in winter than in summer, but the scaphe doesn’t indicate the absolute duration of the day. The scale marks, positioned on the surface in equal distances, do not indicate time intervals of equal length.