It’s one of Leonardo’s most complex machines. The idea consists of wanting to replicate the beating of a dragonfly’s wings, which is more articulated than just a simple up and down motion.
The wings of a dragonfly are flat on the downstroke to push against as much air as possible, while on the upstroke they turn at an angle to meet the least resistance.
Leonardo figured out how to imitate this by designing two pairs of wings that rotate around a central pivot as they go up and down.
