I love the way this thing looks like a cross between some kind of medieval engineering project and the best playground equipment ever. Made by Eske Rex—a Swedish-born designer who'd never heard of the toy Spirograph—it's based on a piece of 19th-century technical equipment.
Instead, he was inspired by the harmonograph, a mid-19th century mechanical apparatus that produces Lissajous curves, a complex family of shapes studied by mathematicians. While the harmonograph uses one pendulum to control a drawing device and a second to control a canvas, Rex's design calls for a two-pendulum device with a static canvas.
The Drawingmachine, Eske's name for his device, which produces art but is also itself considered an installation piece, uses two pendulums supported by large structures that stand at two ends of a similarly large canvas. The pendulums are connected to support systems (drawing arms) that meet in the middle of the canvas at a 90-degree angle and hold a single ballpoint pen, as you can see in the embedded images.
Via The Atlantic