Leonardo da Vinci was not the first person to think of the idea of a parachute, but he designed one in his sketchbook. His invention was a pyramid shaped design that was held in shape by a wooden frame. The tent-like design was to be made out of linen and be as large as 23 meters in length. Da Vinci's intent for this invention was to allow people to be able to jump from great heights and land smoothly without injury. A skydiver in the year 2000 built a parachute designed by da Vinci based on the drawing and using materials that would have been available in the 15th century. The prototype was tested in flight and was successful. Image source: Wikimedia commons, listed as public domain in the United States because it is a photographic reproduction of a public domain work of art.