the fourth dimension, monkey bars, and climbing structures...

images of an old ink blotter advertising the original junglegym, probably 1930's.

the junglegym was designed and trademarked by sebastian hinton in chicago, in 1920. hinton, a lawyer, was married to a schoolteacher at the time. while the idea was indeed to create a climbing structure, according to wikipedia,"hinton's chief goal, was to enable children to achieve an intuitive understanding of 3-dimensional space through a game in which numbers for the x,y, and z axes were called out and each child tried to be the first to grasp the indicated junction. Thus the abstraction of Cartesian coordinates could be grasped as a name of a tangible point in space."

the interesting part, which was not on wikipedia, is that hinton spent part of his childhood in japan. in the early 1900's, his father built a huge bamboo structure in their backyard as a visual representation of the fourth dimension - believing that if people could see the third, they could begin to understand the fourth.

from the web: "Mimicking a Cartesian-coordinate system in mathematics, Hinton’s father named one set of horizontal poles X1, X2, X3, etc. Those horizontal poles at right angles to the X poles were Y1, Y2, Y3, etc., and the vertical poles he identified Z1, Z2, Z3, and so on. Hinton’s father would call out coordinates, "X2, Y4, Z3, Go!", and the children would scramble for that intersection. Hinton said they humored their father with these drills, but what they really enjoyed was simply climbing, hanging, chasing, and playing like monkeys. Now he wanted to build one for his own children."

... and thus the monkey bars were born...