One of two circular diapositive photographs of the full Moon taken by Warren De La Rue [1858-1868] through a 13-inch reflecting telescope with a speculum mirror and using wet colloidon plates. The instrument was carried on a German type clock-driven equatorial mounting housed in his observatory at Cranford, Middlesex.

Circular glass slide, one of two, showing different photographic views of the full Moon taken between 1858 and 1862. Produced by Warren De La Rue (1815-1889), a pioneer of astrophotography, they were used with a stereoscope to produce a three-dimensional panorama of our nearest neighbour in space. De La Rue took these images using his 13-inch reflecting telescope at his observatory at Cranford, Middlesex. This was a difficult task, as the then available wet collodion plates were insensitive to light compared to modern films. This required exposures of several minutes through his telescope using a clock-driven equatorial mounting.