| Abstract from DBPedia | An orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons, usually according to the heliocentric model. It may also represent the relative sizes of these bodies; however, since accurate scaling is often not practical due to the actual large ratio differences, a subdued approximation may be used instead. Though the Greeks had working planetaria, the first orrery that was a planetarium of the modern era was produced in 1704, and one was presented to Charles Boyle, 4th Earl of Orrery – hence the name. They are typically driven by a clockwork mechanism with a globe representing the Sun at the centre, and with a planet at the end of each of the arms.太陽系儀（たいようけいぎ 英語 orrery）とは、地動説を基にした太陽系の模型である。中心に太陽を置き、歯車の回転によってアームに取り付けた惑星の模型を回転することにより、惑星相互の位置を再現する。 (Source: http://dbpedia.org/resource/Orrery) |
