Lunar globe with mechanical stand, 1797.
© Science Museum / Science & Society Picture Library
Published in 1797, this printed Moon globe was produced by the British portrait artist John Rusell RA (1745-1806) and shows the nearside of the lunar surface. Mounted in an elaborate bras stand the whole apparatus was entitled 'Selenographia'. The mechanism was designed to demonstrate Lunar Libration; the slight wobble of the Moon as it rotates. The globe was based on Rusell's accurate measurements and observations of the Moon, which he obtained by using a micrometer with his telescope. Financed through private subscription, only small numbers were ever produced. Even fewer were mounted on an intricate mechanical stand with an asociated explanatory pamphlet.