Aleksandr Boldyrev sundials
Sundials and cultural artifacts
The sun above Russia
Specifications.
Single copy. Brass, patina. Diameter 304 mm. Disc thickness is 14 mm. Thickness of the gnomon is 13.7 mm. The weight without box and technical certificatet is 13.4 kg. The kit includes a product data (technical certificate), screws for mounting the technical certificate and the gnomon, and a wooden box for the instrument storage and transportation.
Related topic.
Description.
The instrument is designed to measure true solar time with the accuracy of ± 4 minutes within the geographical coordinates of 37°37' ± 1 ° East and 55°45' ± 30' North and calculate the value of the mean time at the MSK (UTC + 3) zone according to the wording of 22.07.2014 № 248 F-3 of the Federal Law of June 3, 2011 № 107 F-3.
To convert the true solar time into the mean time a circular graph of the equation of time is etched on the dial face. It lets you know which days of the year the sundial is fast and which days of the year the sundial is slow.
The scale of longitudes is etched on the dial. The names of Russian cities are ranked along the scale according to their longitude. When the shadow of the gnomon falls on the city name it means that in this city a true noon has come and the sun crosses the meridian of the city.
In the eastern part of the dial, there are the State Russian coat of arms and the inscription: «For 11 hours and 20 minutes the sun is above Russia.» It means that it takes the sun 11 hours and 20 minutes to pass the distance between the most eastern and the most western part of the country.