Nasmyth's reflecting telescope and two models of the lunar surface, 1866.

Calotype print taken in 1866 by James Nasmyth (1808-1890) showing his 20-inch reflecting telescope 0f 1858. A succesful industrialist and engineer, Nasmyth used this telescope to made extensive observations of the Moon. Working from his drawings, he calculated the height of the lunar features by measuring the length of their shadows. These were then photographed with suitable lighting to produce better results than could be achieved at the time with direct lunar photography. Nasmyth went on to photograph a whole series of his lunar models. They were used to illustrate the book, 'The Moon' that Nasmyth published in 1871 with James Carpenter.