Shortly after, a more sophisticated parachute was sketched by the polymath Leonardo da Vinci in his "Codex Atlanticus" (fol. 381v) dated to ca. 1485. Here, the scale of the parachute is in a more favorable proportion to the weight of the jumper. Leonardo's canopy was held open by a square wooden frame, which alters the shape of the parachute from conical to pyramidal. It is not known whether the Italian inventor was influenced by the earlier design, but he may have learned about the idea through the intensive oral communication among artist-engineers of the time. The feasibility of Leonardo's pyramidal design was successfully tested in 2000 by Briton Adrian Nicholas and again in 2008 by the Swiss skydiver Olivier Vietti-Teppa. According to the historian of technology Lynn White, these conical and pyramidal designs, much more elaborate than early artistic jumps with rigid parasols in Asia, mark the origin of "the parachute as we know it."