Planisphere

Planisphere. The projection is geocentric and equidistant from the South Pole to North 60°. Only the principle stars, connected by lines, are included. On the back, there is a magnitude table, which is labelled. The Milky Way is also labelled. A total of 22 stars and one star group are named. The Ptolemaic constellations below declination North 50° and three non-Ptolemaic constellations are drawn. One of the 12 constellations of Plancius is drawn as well as six of Hevelius and six of Lacaille.

The planisphere consists of a quadrangular cardboard base-plate and a circular disc with a celestial map, which can revolve around the North Pole in the centre. On top of the map is a horizon disc of cardboard covered with leather. The horizon disc has an oval cutaway, exposing the visible part of the sky at latitude S 35° - that of London - for which this planisphere is constructed. In the four decorated corners of the horizon disc there are apertures for reading the scales. These corners are fixed to those of the quadrangular base-plate, thus keeping the parts together. On the back of the base-plate, there is an 'EXPLANATION' with an instruction for use. For further information about this planisphere please refer to the related publication, Globes at Greenwich.

Object Details

ID: AST0588
Collection: Astronomical and navigational instruments
Type: Planisphere
Display location: Not on display
Creator: George Philip & Son Ltd
Date made: circa 1940
Credit: National Maritime Museum, Greenwich, London
Measurements: Diameter: 260 mm