We decided to include the Spirograph on this site because it played a prominent role in our childhood. The Spirograph toy was developed in 1965 and sold in the USA by Kenner in 1966, but the idea was first hatched by a mathematician named Bruno Abakanowicz in the late 19th century. By the early 20th century, Sears was selling a gear driven set called the Marvelous Wondergraph. The Spirograph proved to be so popular, that it continued to be produced and sold well into the 1970’s, 1980’s, and well beyond.
Essentially, the Spirograph was a set of different sized plastic rings, with gear teeth on the outside and inside rings, which had holes in them for pens. You would stick a pen through the holes of the inner ring, and then rotate around the gears of the larger ring, effectively making hypotrochoid and epitrochoid shapes. If you were like us, your Spiroprah went back in the box when the pens ran out of ink, and you did not open it up again until you had kids of your own.