Nocturnal

Combined nocturnal, lunar volvelle and Rojas projection. This instrument is more of a compendium than a pure nocturnal, but the shape shows that it was mainly used as a nocturnal. The Rojas projection allows it to be used as a sundial, and the inclusion of a lunar volvelle means that it could have been used as a moon dial. It is an elaborate instrument with generally high quality engraving, although a mistake was made in the numbering of the lunar age scale, with the final division lying between 28 and 29. For use with the Little Bear. The instrument is held together by a screw and wing nut, rather like an astrolabe. The handle is pierced and decorated. Obverse has two rotatable discs and pivotal pointer arm. Main disc is divided anticlockwise into zodiac. Date scale lies within this, with named months. Lower rotatable disc with hour and lunar age scale. Upper rotatable disc has long pointer with aspectarium and pictorial representation of the phases of the moon. Rotable disc has eight main winds marked in Italian, and the Rojas projection. Declination parallels are drawn between the Tropics and according to the zodiac signs. Hour lines are drawn, and marked. Short pointers are used to set the latitude. PIvoted over this is an alidade, which meet two brass arcs where a string and bob would have been attached. Washer and wing nut at centre.

Object Details

ID: AST0130
Collection: Astronomical and navigational instruments
Type: Nocturnal
Display location: Not on display
Creator: Leonae, Amerigo
Date made: 1589
Credit: National Maritime Museum, Greenwich, London, Caird Collection
Measurements: Overall: 199 x 11 x 97.5 mm
Parts: Nocturnal