February 2007
One of the Consortium’s newest members, Matthew Read, is a specialist in the repair and conservation of historic clocks and horological instruments. He has recently undertaken, on behalf of the Royal Observatory at Greenwich (part of the National Maritime Museum), the complete overhaul of the Museum’s 18th century orrery. The restored orrery is to be a key object in the Observatory’s new £15 million Time and Space project, due to open to the public this summer.
A planetarium, or orrery, is a mechanism or “philosophical instrument” which shows the relative position and movement of the bodies of the Solar System. It derives its name from Charles Boyle, 4th Earl of Orrery, a wealthy “natural philosopher”, who in the late 18th century commissioned one of these instruments for himself. Some were manually operated; others like the NMM’s were driven by clockwork. The speed of the rotation of the planets and their moons approximated to real life, though the interplanetary distances did not.
Prior to conservation the orrery was in reasonable condition, but a dislodged driving wheel had rendered it inoperable. Conservation therefore involved completely dismantling the mechanism, carefully photographing all parts and assemblies, thorough hand-cleaning of all parts, effecting the minimum necessary repairs, and finally re-assembling the mechanism using suitable lubricants and protective coatings. The orrery is now successfully running on test, and is ready to take its prominent place on display. (Photograph by kind permission of the NMM)