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
Geometric and Functional Analysis "Geometric Aspects of Functional Analysis" of which Vitali Milman had been one of the main organizers in the previous years. The journal retained the same acronym as the series to stress the connection between the two. The journal is reviewed cover-to-cover in Mathematical Reviews and Zentralblatt MATH and is indexed cover-to-cover in the Web of Science. According to the "Journal Citation Reports", the journal has a 2015 impact factor of 1.476. The journal has four editors: Vitali Milman (editor-in-chief), Mikhail Gromov, Simon Donaldson and Peter Sarnak. Geometric and Functional Analysis "Geometric and Functional Analysis" ("GAFA") is a mathematical journal published