Spirograph Spirograph Spirograph is a geometric drawing toy that produces mathematical roulette curves of the variety technically known as hypotrochoids and epitrochoids. It was developed by British engineer Denys Fisher and first sold in 1965. The name has been a registered trademark of Hasbro Inc. since 1998 following purchase of the company that had acquired the Denys Fisher company. The Spirograph brand was relaunched worldwide with original product configurations in 2013 by Kahootz Toys. In 1827 English architect and engineer Peter Hubert Desvignes developed his "Speiragraph", a machine to create elaborate spiral drawings, intended to prevent bank note forgeries. The mathematician
Denys family Denys family The surname Denys was borne by at least three prominent mediaeval families seated in Gloucestershire, Somerset and Devon in south-west England between 1166 and 1641. It is not known if any relationship existed between these families. The surname "Denys" is just one of many variant spellings of the name: "Denise", "Le Deneis", "Le Danies", "le Deneys" and most recently "Dennis", are some of the others. The family of Denys was apparently of Danish origin, and was recorded in early Norman charters in French as "le Deneys", meaning "The Dane", which was frequently Latinised by scribes as Dacus, being