Somerville’s importance is as a connectionist and interpreter of maths and science, and as a trailblazer for other women. Nasmyth taught her painting; a chance comment of his set her off studying geometry. Brewster, Scott and Playfair (who encouraged her) were close Edinburgh friends. In London, she introduced Lovelace to Babbage, was strongly supported by John Herschel, and met Arago and Biot (who introduced her to leading colleagues in Paris). Laplace, whose work she translated and elucidated, said she was one of only two women to understand it. She had an extensive circle of friends from Italy to America.