What's the difference between i.e. and e.g.?
machine designed to fly by the flapping of its wings in imitation of birds. The wooden bird said to have been made about 400 BC by Archytas of Tarentum is one of the earliest examples. The Greek myth of Daedalus and Icarus involves man's use of wings in the manner of birds. Leonardo da Vinci made many drawings and models of such aircraft in the late 15th century. Although a few short flights have been recorded, ornithopters remain impractical.