An engraving from Nasmyth's biography entitled 'The Large Telescope'. Nasmyth was a wealthy engineer who had a lifelong interest in astronomy and constructed this 20-inch reflecting telescope in the grounds of his home in Patricroft in Manchester. He used the telescope to observe the Moon's surface and make drawings, calculating the height of lunar features by the length of their shadows. These were then reconstructed in plaster and lit carefully to clarify the various features. The resulting photographs produced better results than could be achieved at the time by direct lunar photography. Nasmyth photographed a whole series of his lunar models which were used to illustrate a book, 'The Moon', that he published with James Carpenter in 1871.
© Science Museum / Science & Society Picture Library