The Chinese were flying kites by 1000 B.C. and may have tried to make them fly stringless, but in Europe it all started, as did so many things, with Leonardo da Vinci in around 1500. After trying to imitate bird flight with flapping wings, and failing to realise that man’s muscle power was not enough to produce lift by flapping, he designed a device with a fixed wing with flapping tips, and thus separated the functions of lift and thrust. He also had the idea of a helical screw helicopter, probably powered either by clockwork or by a twisted steel wire. He died in 1519 and his notes were not discovered till the nineteenth century. Without this 300 year lapse, gliders at least might have been flying by 1600, though the lack of suitably light yet strong materials held back development; cord, cane, paper, leather and feathers was all that was available.