ORRERY
orrery
(noun) planetarium consisting of an apparatus that illustrates the relative positions and motions of bodies in the solar system by rotation and revolution of balls moved by wheelwork; sometimes incorporated in a clock
Source: WordNet® 3.1
Etymology
Noun
orrery (plural orreries)
A clockwork model of any given solar system.
Source: Wiktionary
Or"re*ry, n.; pl. Orreries. Etym: [So named in honor of the Earl of
Orrery.]
Definition: An apparatus which illustrates, by the revolution of balls
moved by wheelwork, the relative size, periodic motions, positions,
orbits, etc., of bodies in the solar system.
Source: Webster’s Unabridged Dictionary 1913 Edition