Ἀγεωμέτρητος μηδεὶς εἰσίτω

Birthday of a country house

Specifications.

Single copy. Brass, patina. Crimean limestone. The diameter is 1 foot (305 mm). The height of the pedestal is 850 mm.

Description.
The instrument has a single scale designed to register true time at the meridian of Krasnogorsk (Moscow region). A circular nomogram is in the center consisting of both uniform and non-uniform scales. The uniform scale consists of 365 parts (by number of days in a year) and is divided into sections corresponding to the length of months. In addition, it is divided into four unequal periods showing what time of year the sundial fasts or slows. Non-uniform scale indicates the equation of time for each day of the year. *

The conical gnomon registers the anniversary date. October 11, the shadow of conic gnomon goes along a specially designed curve that crosses the dial face from east to west.

* — As an analogy it is used a nomogram method applied to the sundial made by “G and CW Dixey. Opticians of Her Magesty, New Bond Street London”. This sundial is now in Bicton Park Botanical Garden (UK).