[Machine Translation] / Leonardo da Vinci left his mark on an extremely wide range of fields, with his expertise in painting, sculpture, architecture, civil engineering, and the science and technology of the human body. We have collected products approaching his face as an inventor as pre-painted kits. Leonardo's catapult seems to be a re-study of a weapon already known at the time, newly utilizing a spring mechanism. Especially, it seems that he sketched several patterns for the spring-loaded part, and we can assume that the real research was not on the catapult but on its structure. The old weapons must have been interesting to Leonardo.