Of the unsupported myths--unsupported, that is, by even a shadow of probability--there is no end. Although Latin legend approaches nearer to fact than the Greek in some cases, in others it shows a disregard for possibilities which renders it of far less account. Thus Diodorus of Sicily relates that one Abaris travelled round the world on an arrow of gold, and Cassiodorus and Glycas and their like told of mechanical birds that flew and sang and even laid eggs. More credible is the story of Aulus Gellius, who in his Attic Nights tells how Archytas, four centuries prior to the opening of the Christian era, made a wooden pigeon that actually flew by means of a mechanism of balancing weights and the breath of a mysterious spirit hidden within it. There may yet arise one credulous enough to state that the mysterious spirit was precursor of the internal combustion engine, but, however that may be, the pigeon of Archytas almost certainly existed, and perhaps it actually glided or flew for short distances--or else Aulus Gellius was an utter liar, like Cassiodorus and his fellows. In far later times a certain John Muller, better known as Regiomontanus, is stated to have made an artificial eagle which accompanied Charles V. on his entry to and exit from Nuremberg, flying above the royal procession. But, since Muller died in 1436 and Charles was born in 1500, Muller may be ruled out from among the pioneers of mechanical flight, and it may be concluded that the historian of this event got slightly mixed in his dates.