This week’s That’s Maths article, TM003, describes the analemmatic sundial on the East Pier in Dun Laoghaire.
An article in Plus Magazine, by Chris Sangwin and Chris Budd, gives a description of the theory of these sundials and instructions on how to build one.
A script to design an analemmatic sundial, written by Alexander R. Pruss, is available here. To run it, just enter the width of the sundial, the latitude and longitude, and the timezone. The script will generate all the required dimensions.
Here is a technical article, The Equation of Time and the Analemma (PDF), submitted to the Bulletin of the Irish Mathematical Society.
ThatsMaths 