Between 1839 and 1853 the French mathematician Théodore Olivier created string models to teach and demonstrate descriptive geometry, some of which could be manipulated. He was a student of French mathematician Gaspard Monge, who invented descriptive geometry and was already illustrating his ideas with rudimentary string models. Photo above: intersection of two cylinders. Sources: Nicholas Mee (2013) Strings, Surfaces and Physics. Photo above taken in the Musée des Arts et Métiers in Paris, see […]

Model by Alexander Crum Brown (1838-1922) of a half-twist mathematical surface, featuring a non-Euclidean so-called Klein bottle, c. 1900. Sources: Photo from the Science Museum, London, textual description courtesy of Klaus Hentschel. For more, see Klaus Hentschel (2014): Visual Cultures in Science, Technology and Medicine, pp. 96ff. and pl. XIV.