Celestial globe, 1693.
© Science Museum / Science & Society Picture Library
This detail, centred on the constellations of Sagittarius (the archer) is from a large celestial globe asembled in Paris, France by Charles Delagrave. The engraved star patterns are 18th century copies of the original ones used by the 17th century Venetian mapmaker, Vincenzo Coronelli (1650-1718). The celestial globe is a three-dimensional model of the heavens on which the stars are plotted on the outside of a sphere. Originating in the Ancient World, it was probably inspired by the discovery that the Earth was round. The globe could be used to teach and demonstrate various astronomical principles. Until recently most celestial globes were ornate with decorative figures obscuring the stars.