An Orrery Preamble

Devices to track the positions of the celestial bodies have been around for centuries, the earliest example know is the Antikythera mechanism that has been dated to 2nd Century BC although some academics believe it could be even older with some romancing ideas towards Archimedes as its possible architect.  
The Antikythera mechanism is based on the geocentric model which places the Earth at the centre of the universe whilst the Sun, Moon, stars and planets orbit. Little is know about the Antikythera mechanism, it appears so advanced of the date to which it has been prescribed that it can only be described as an oddity. A device with gears as complex will not be built again until the European Astronomical clocks of the late middle ages. These early Astronomical Clocks and the Antikythera mechanism would have been designed to inform on upcoming annual occasions, as well as a tool to help map tides, weather patterns and day lengths.
The Orrery was a natural heir to the Astronomical Clocks, making its first recorded appearance 1704. Unlike its predecessors the Orreries principles were based on the new heliocentric model of the universe placing the Sun at the centre.