Regiomontanus dial for latitudes 30°-66° North. This dial comprises a rectangular gilt-brass plate with a regiomontanus dial on one side and a nocturnal on the other. The upper section of the plate is occupied by a trigon in which are drawn the zodiacal divisions crossed by horizontal parallels of latitude. On the left-hand edge is a table of latitudes for various places in Europe and on the right-hand edge is a table of stars and a zodiac scale for setting the bead. An articulated arm is pivoted to the plate at the top of the trigon. It has a hole at its free end to which is attached a string carrying an indicator bead (both replacements) and a brass plumb bob. The nocturnal consists of a fixed disc engraved on the main plate, a rotatable hour disc and a rotatable index arm. The equinoxes are marked at 10 ½ March and 12 ½ September. Within the date scale the 18 stars from the dial are marked and numbered.

The engraving on this instrument is of a high quality. It would probably have been made for an aristocratic buyer, most likely German, given the large number of German towns listed in the table of latitudes. The nocturnal allows it to be used at night by locating the stars that are numbered on the nocturnal and named on the front of the dial. It is signed 'Iohannes Krabbe Mündensis Faci: 1584'.

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