ASTROLOGY - ORRERY, AND PLANISPHERE Engraving of an 18th century orrery, or model of the solar system (left), with a three dimensional planisphere, with the earth at the centre of the concentric planetary spheres (right). This latter model was copied on to the statue of the Freemason, the assassinated (1881) President of the United States, James Garfield, which stands to the south-west of the Capitol Building, in Washington DC. Engraved plate from James Ferguson, Astronomy Explained upon Sir Isaac Neston's Principles, and made Easy to Those who have not Studied Mathematics, 1757.