Work of our members

On the completion of the Artis Planetarium in 1988, the builder, Tetteroo, presented this sundial.

Calculations and basic design of the sundial are by me; the artistic interpretation by artist Joep Coppens of Vlierden.

The lower half is the actual sundial. A small dial around the foot indicates Amsterdam apparent local time.
The large scale shows legal time, including longitude correction and the Equation of Time.

There are two scales, each of which is fitted on the sundial in turn for half a year; one for lengthening, and one for shortening days.
As far as I know, this is the only sundial in the Netherlands with interchangeable half-year time scales.

As Marinus Hagen, initiator of the Dutch Sundial Society, once observed: The scale exchanges should really be accompanied by a ceremony.

J.G.T.M. Taudin Chabot