Equinoctial ring-dial signed "A.C. Toblhanhb Mockba" (i.e. A.S. Trinidin, Moscow) undated, 18th century. The back of the instrument an showing the Zodiac declination scale, which is very well provided with transversals.

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: Equinoctial ring-dial signed "A.C. Toblhanhb Mockba" (i.e. A.S. Trinidin, Moscow) undated, 18th century. The back of the instrument an showing the Zodiac declination scale, which is very well provided with transversals. Wellcome Collection. Source: Wellcome Collection.