Allegorical portrait by Julia Margaret Cameron (1815-1879). Cameron's photographic portraits are considered among the finest in the early history of photography. She set up a private studio at her Isle of Wight home at the age of 48, after her daughter gave her a camera, and she became expert at using the collodion wet-plate proces. She used friends, servants and neighbours as subjects, including the scientists Charles Darwin and John Herschel, and the poet Alfred Lord Tennyson.
© National Museum of Science & Media / Science & Society Picture Library