Spirograph a hypocycloid. 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.
Toy balloon Toy balloon A toy balloon or party balloon, is a small balloon mostly used for decoration, advertising and children's toys. Toy balloons are usually made of rubber or aluminized plastic, and inflated with air or helium. They come in a great variety of sizes and shapes, but are most commonly 10 to 30 centimetres in diameter. Toy balloons are not considered to include "sky lanterns" (hot-air paper balloons), although these too are or were used as child toys in some parts of the world. According to The Journal of the American Medical Association, out of 373 children who died in