Some time back we reported on the tellurian designed and made by Anthony Gilbert. The idea was to produce a design which could be incorporated in a clock, Jayeltea, now shown here.

A tellurian is an apparatus designed to illustrate how day and night are caused by the rotation of the earth on its axis, and the dependence of the seasons on the sun's declination.

Anthony Gilbert based his prototype tellurian, Protel, on a gear train designed by the late John Lock. It was scratch built with 20DP gears to validate the design and test the feasibility of building a smaller scale version which could be combined with a skeleton clock.