Denys Fisher Denys Fisher Denys Fisher (11 May 1918 – 17 September 2002) was an English engineer who invented the spirograph toy and created the company Denys Fisher Toys. He left Leeds University to join the family firm, Kingfisher (Lubrication) Ltd. In 1960 he left the firm to set up his own company, Denys Fisher Engineering, in Leeds. In 1961 the company won a contract with NATO to supply springs and precision components for its 20 mm cannon. Between 1962 and 1964 he developed various drawing machines from Meccano pieces, eventually producing a prototype Spirograph. Patented in 16 countries, it went on
Mathematical visualization Mathematical visualization Mathematical visualization is an aspect of geometry which allows one to understand and explore mathematical phenomena via visualization. Classically this consisted of two-dimensional drawings or building three-dimensional models (particularly plaster models in the 19th and early 20th century), while today it most frequently consists of using computers to make static two or three dimensional drawings, animations, or interactive programs. Writing programs to visualize mathematics is an aspect of computational geometry. Mathematical visualization is used throughout mathematics, particularly in the fields of geometry and analysis. Notable examples include plane curves, space curves, polyhedra, ordinary differential equations, partial differential equations