Date: 17-12-2000
Owning Institution: The Ambrosiana Library, Milan
Publication:     Sunday Telegraph “In The Picture”  
Subject:   Renaissance    

On the anniversary of the Wright brothers’ first flight, today’s picture is a design for an early experimental prototype of a flying machine. It was drawn by Leonardo da Vinci sometime during the mid-1490s but only came to light after his death. He hid such work jealously from his contemporaries, scared that they might steal his ideas. In 1596, while making plans to build a version of the machine shown here, Leonardo wrote himself a memo: “Close up with boards the room above and make the model large and high … If you stand upon the roof at the side of the tower the men at work upon the cupola of the neighbouring cathedral will not see you.”

In late fifteenth-century Milan, Leonardo was just one of a large number of freelance artists, engineers and other Renaissance men of ingenuity competing for work at the court of the Sforza. If he could design the first fully functioning flying machine his reputation would be made. “The great bird will take its first flight,” he wrote dreamily, “filling the world with stupor and all my writings with renown, and bringing glory to the nest where it had been born.”

Leonardo always referred to his design as “the great bird”. It is not strictly speaking an aeroplane but an ornithopter, modelled on avian anatomy and motion. “A bird is an instrument working according to mathematical law,” he believed, “which instrument it is within the capacity of man to reproduce with all its movements…” The daring (and extremely energetic) aeronaut was intended to occupy the pod between the two wings in Leonardo’s design. Then, using a system of rods, ropes and levers – somewhat schematically indicated in his drawing – he was to heave or row away with sufficient vigour to cause the machine’s mighty wings of canvas and cane to flap. In this way, Renaissance man would reach for the sky. That, at least, was the theory.

Leonardo is said to have loved birds, often buying them simply to set them free from their cages. In childhood he had had a vivid dream about a great kite hovering over him and striking him “many times between the lips” with its tail. Sigmund Freud was inspired by this to write a book about Leonardo, propounding for the first time his theory of the fetish (“a substitute for the mother’s penis that the little boy once believed in and does not want to give up”) and scandalising a generation of art historians in the process. “The workings of a powerful and complex mind… cannot be explained by a rather one-sided system of psychology,” Sir Kenneth Clark noted disapprovingly.

Had it not been for Leonardo’s preoccupation with birds his flying machine might have had more chance of working. His devotion to the ornithopter principle was the fundamental error in his approach to aeronautics. He assumed that man’s muscular power was sufficient to enable him to flap a pair of mechanical wings fast enough for him to fly. But as the scientific historian Ivor B. Hart explains, “Leonardo’s comparison between birds and man left out of account… the relative disparity of muscular power between the two species in relation to overall weight. Leonardo’s flying machines were designed to be worked by the muscles of the pilot’s arms and legs – a muscle power of from a fifth to a quarter of his total weight. But in the case of the bird, the flying muscles account for as much as up to half the total weight.” Given the additional dead weight of the contraption itself, Leonardo’s flying machine could never have flown.

He seems gradually to have realised that he was on the wrong track. In later life he began to think along the lines of a more rigid type of construction, that might glide or soar rather than flap. He was inspired by the sight of autumn leaves moving from side to side through the air as they fell. He did some drawings of men strapped to the underside of leaf-shaped constructions which seem strikingly to prefigure the modern hang-glider.

Leonardo was not the only man of his time to dream of flight. C.H. Gibbs-Smith, in his A History of Flying, tells of John Damian, an enterprising Italian alchemist who became court physician to James IV of Scotland and broke his thigh bone attempting to fly from the walls of Stirling Castle. In sixteenth-century China, a certain Wan-Hoo fixed a saddle between two large kites, tied forty-seven rockets to them and lit the touch paper. “The intrepid Chinese,” says Gibbs-Smith, “departed to his ancestors to the accompaniment of much noise and smoke.”

Nobody knows whether Leonardo ever attempted to take to the air in his own flying machine. Some tantalising entries in his notebooks suggest that he may indeed have done so. “To-morrow morning on the second day of January 1496 I will make the thong and make the attempt,” he writes, with bravado. Then, a little more circumspect, he says that it might be best to try the machine “over a lake”, and reminds himself to “carry a long inflated wineskin as a girdle so that in case you fall you will not be drowned.”

Had it not been for that wineskin, perhaps, how differently history might have turned out. The Last Supper might never have seen the light of day; and there might not be 2,000 tourists in the Louvre at this moment, taking photographs of their own reflections in the bulletproof glass protecting the Mona Lisa.