Forged horizontal dial for latitude 45° North. Square marble dial. On the obverse side is an hour scale and eight wind directions marked in Latin. At the gnomon base is a depiction of the sun with a human face, around which is engraved the motto: 'Horas non numero nisi serenas' (I only count the bright hours). The brass gnomon is shaped and depicted as a grotesque, horned moon face. The compass is inset south of the gnomon with the cardinal points named in Latin. On the reverse side is a lunar volvelle, carrying a table of epacts, an hour-circle and an Age of Moon scale. Around the edge is engraved 'Circulus Epactarium secundum Cat. Greg. Usque ad ann. Milles. - Septing', (Circle of epacts according to the Gregorian Calendar, until the year 1700).

The dial has a black leather square case with a separate lid to accommodate the gnomon. The base of the case contains two manuscripts, one of vellum, the other of paper. These provide details of the alleged first and later owners. At first sight this dial appears to be a sixteenth-century instrument with unusually full documentation of its provenance. However, the inclusion of an epact table given 'according to the Gregorian Calendar' clearly marks the instrument as a forgery, since the Gregorian Calendar was not introduced until 1582. Other indications of forgery are the style of the engraving, the decoration on the gnomon and around its base, and the addition of a motto around the gnomon. On the gnomon, it has the fake signature 'B. Sabeius 1552 Patauii Latit. 45'.

For more information regarding this dial please refer to the OUP & NMM catalogue, 'Sundials at Greenwich'.