Denys Fisher sale in Schofields department store in Leeds in 1965. A year later, Fisher licensed Spirograph to Kenner Products in the United States. In 1967 Spirograph was chosen as the UK Toy of the Year. Denys Fisher Toys, which also produced other toys and board games, was sold to Palitoy in 1970 and it was subsequently bought by Hasbro. Through the 1980s & 1990s Fisher continued to work with Hasbro in developing new toys and refining Spirograph. Denys Fisher Toys produced the following toys and games: Denys Fisher Denys Fisher (11 May 1918 – 17 September 2002) was an English engineer
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