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Instrument

Orrery

Physical Sciences
Orrery glyph

An orrery is a mechanical, usually clockwork, model of the Solar System that illustrates or predicts the relative positions and orbital motions of the planets and, often, their moons around the Sun. The London instrument maker John Rowley built a copy of a design by the clockmaker George Graham around 1712 for Charles Boyle, 4th Earl of Orrery, and the device subsequently took the Earl's name in English. Earlier orreries were generally built to represent only the planets known at the time of construction, extending no further than Saturn until William Herschel's discovery of Uranus in 1781 extended the known Solar System outward.

Facts
Invented Year
1712 1
Sourced to the subject's own accountDate of John Rowley's copy of George Graham's design for the Earl of Orrery, the device from which the English name derives; simpler geared planetary models predate it.
MeasuresSourced to the subject's own account
Does not measure in the sense of taking a reading; instead it models and predicts the relative positions and orbital motions of the planets (and often moons) around the Sun. 1
Operating PrincipleSourced to the subject's own account
A clockwork or hand cranked gear train turns a set of arms carrying models of the planets around a central globe or light representing the Sun, geared so the arms turn at relative speeds approximating the planets' real orbital periods. 1
Operating RangeSourced to the subject's own account
Built to represent the Solar System as known at the time of construction; most eighteenth century orreries extended only to Saturn, the outermost planet known before Uranus was discovered in 1781. 1
Open Questions
Resolution
Not applicable; an orrery is a scale demonstration model rather than a measuring instrument.
Not applicable as a numeric figure in the cited source; an orrery is a scale demonstration model rather than a measuring instrument.
Connections

Invented By

Source George Graham (Wikipedia)

Used In

Astronomy, Disciplines

A teaching and demonstration model of the Solar System's planetary motions.

Source Orrery (Wikipedia)
Sources
1. Orrery (Wikipedia)
Wikipedia
  • Lead section
    An orrery is a mechanical model of the Solar System that illustrates or predicts the relative positions and motions of the planets and moons.
  • Used In: Astronomy
View the Source
George Graham (Wikipedia)
WikipediaInvented By: George Graham, Career section
Quote, Invented By: George Graham, Career section
constructed the most complete planetarium known at that time, in which the motions of the celestial bodies were demonstrated with great accuracy. This was made in cabinet form, at the desire of Charles Boyle, 4th Earl of Orrery
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