An electrotype copy of a plaster replica of the lunar crater Eratosthenes, made by the amateur astronomer Henry Blunt and framed in a wooden case. The model is based on observations of the Moon made by Blunt with his reflecting telescope from his home in Shrewsbury, Shropshire. The main crater in the electrotype corresponds to a lunar feature 28 miles (45 km) acros. The model was donated to the Science Museum by the Commisioners of the Great Exhibition and was probably displayed at the 1851 world exposition held in the Crystal Palace in Hyde Park, London. The model is described in the exhibition catalogue, but other examples of lunar models by Blunt are also known to exist. © Science Museum / Science & Society Picture Library