An orrery is a specific type of planetarium, which is the general term used to describe 3D models of the solar system. Other types of planetaria include Telluriums, which show how days, nights and the seasons are created by Earth’s rotation, axial tilt and orbit around the Sun; Lunariums, which show the complex motions and phases of the Moon; Astrariums, which demonstrate the cyclical nature of celestial objects like an astrological clock; and Armillary Spheres, which use spherical rings to illustrate the relative geometry of the heavens with respect to Earth.

The earliest known orrery, named the Antikythera Mechanism, dates back over 2,000 years to Ancient Greece. It was discovered in 1901 in a shipwreck off Antikythera island and was capable of accurately predicting astronomical positions and eclipses decades before their occurrence.

So surprising was its complexity and accuracy that it has been dubbed the oldest example of an analogue computer. Indeed, technological artifacts of equal sophistication did not reappear until the development of mechanical astronomical clocks in Europe in the fourteenth century.

However, in 1543, Polish astronomer Nicolaus Copernicus turned everything on its head by proposing that, in fact, the Earth orbits the Sun. This created a paradigm shift in mankind’s conception of the universe and contributed significantly to the Scientific Revolution and the emergence of modern science.

In the century that followed, great progress was made in understanding the structure of the solar system and by the 18th Century, heliocentric models were being made to demonstrate these discoveries.

History tells that Graham gave the first model, or its design, to the celebrated instrument maker John Rowley of London to make a copy for Prince Eugene of Savoy.

Rowley was subsequently commissioned to make a further copy for his patron Charles Boyle, 4th Earl of Orrery, from whom the device took its name.

The fascination that these advances inspired in the general population is clearly depicted in the painting ‘A Philosopher Lecturing on the Orrery’ by Joseph Wright of Derby, who became the unofficial artist of the Enlightenment. The wonder and awe expressed in the faces of the children, and the nearby adult taking copious notes, says it all.