Leonardo da Vinci Wing. Fourth Day

I fashioned a fabric wing from one piece of light weight cloth. I sewed the edges with the scallops, as seen in the da Vinci drawing, and used a straight stitch with the ends left loose so that one can pull them to tighten the edges as need be. 

I had to pierce the fabric and reinforce it with more stitching to enable the small levers beneath the wing fingers to be set in place. Then I ran strong and unstretching fishing lines from the levers, through the pulley system, and to the handle. 

There was much fussing and distress while I tied the corners to the ends of the fingers and ran the strings from the driving lever to the projecting attachment  points. The whole contraption was becoming unruly and hard to manage, with a small mishap that caused a fracture in one of the fingers, and which led to much cursing and dismay. But I was able to bind this up with glue and a tight winding. 

The final assembly reminded me rather more of a severed duck's foot than of a wing. The webbed foot will close up if you pull on a tendon. 

I'm afraid to say the wing worked no better for being finished, despite the light weight of the cloth. It was still necessary to work the driving lever so that it raised the wing before it could be brought in a downward flapping motion. The strings worked to some degree of action to close the wing fingers and to catch the air, however the weight of the whole structure made everything tend to sag downward. If I were to imagine stronger spring steel to ensure the fingers remain straight, and if I we're to imagine a counterweight to make the wing point upward before it is driven down, then I would perceive a device so full of counteracting forces that the effort required to make any appreciable movement would require the weight of an elephant. And elephants, I'm sure, will never fly. 

The Florentine is a masterful painter; I have seen his work and it bears a divine 

genius that seems to give solid form to the flat painted canvas. His pen rendition of a flapping wing encourages unquestioning belief, but the reality of his design, as drawn, falls short of its intent in construction. Yet he has these visions that surpass the thoughts of the common man. One has to wonder if, in the future, new materials that are lighter and stronger than any we know today may yet be discovered or devised. New methods of driving force into the working of the wings may indeed bring the power of a herd of elephants into the hands of puny man. And then, yes, elephants may fly. 

Leonardo da Vinci

January 10, 1501

Some time ago I received a visit from a servant to the Duke Ludovico Sforza. He presented me with a small bag of seven ducats and a letter of request stating that I was to build a working model of a devise designed by master Leonardo da Vinci, the Florentine, and that it was to be ready in four days for a presentation at the ducal court. 

Within an hour a servant from Leonardo's workshop arrived with a drawing of a flying wing contraption. With the help of a mirror we read the adjoining text." Is there not more?" I asked. The drawing and text were insufficient I felt. The servant said he would come back with more notes, and I set to work making my own sketches to fully understand the nature and intent of the da Vinci machine. 

I first thought my way through the quick sketch of a single arm. I saw a point of pivot and the leading of a rope. The placement of the pulleys meant that the arm, when moved, would straighten or clench like a waving hand.

But while I could see the down-ward pull of the ropes I wasn't sure how the wooden finger would straighten. 

When the servant returned with a sheaf of papers I reached for them eagerly. He held them back to his chest! "Three Florins", he said.

"You Imp! " I cried, " what of the Duke's order?"

"Yes", he said, " it would be a shame to fail."

I said I would speak with master Leonardo but he told me the master was away in Florence. I asked his name so I could report him for his scurrilous insolence. He said he was know as "Salai". Yes, I thought, a real "devil"

I realized I had no choice so I paid him a few coins and in an hour and was able to peruse the mirror text. I was able to glean enough of the information I needed and could then dismiss him with a box to the ears for his insolence. I then put myself to the second drawing. 

I knew I  had enough old wood for the job but went at once to my friend Stefano, the blacksmith, for necessary spring steel and ring bolts, and to my brother Andreo, the sailmaker, for cloth and cordage. By the end of the first day I had amassed all my materials. 

Right now had only three days to complete the model. By the Duke's instructions I knew that this model was to be true to Leonardo's drawings but that my job was to reveal only design issues that needed correction, and that I was not to attempt my own innovations. 

That was a small relief. 

ON THE SECOND DAY my goal was to complete the structure of the "bones" for the working wing. I spent the morning making the central finger and connecting it to the horizontal member which I turned on a lathe. This served as an axle with two extending fingers to help spread the wing. The work with the wood was easy, for that is my trade, but manipulating the spring steel and making the joint work was harder. In the end, however, I was able to get both sufficient spring and flexible stiffness in the joint by using some leather members on either side and, ultimately, stitching a sheath of leather over the whole joint. 

With this one component made it was quick and easy to follow up with four other fingers angled into the main axle so they would fan out, and then to add two static rods as a last way of spreading the final fabric. 

MY TASK ON THE THIRD DAY was to fashion the bearing arms for the wing, to join the wing to the driving lever with two inter-locked steel rings, and to make the structure through which the driving lever could operate. Again, these tasks were easily accomplished with the help of good augers, and sharp chisels and saws, so as to create the necessary mortises and tenons. My friend Stefano also came through with the last elements required, namely the two inter-locking rings and some good steel spikes. 

I mounted this all on a solid base ready for the first trial, and was proud of myself for realizing that the one driving lever would have to be without a point of pivot to ensure that the thrusting aspect of the system would not cause the levers to bind and be locked in place. 

In my first fledgling attempt at working the wing I was shocked to realize that the downward thrust, as implied by da Vinci's drawing, was an impossibility. 

The sheer weight of the wing structure itself made the wing fall downward. I had to apply considerable force and directional manipulation in order to raise the wing and resist its wish to fall. 

At first I was aghast and felt the sweat of fear that I had failed in my job. But then I realized my job was simply to represent the drawings of the great Florentine and, to my best ability, to neither add not take away any element but that which was clearly illustrated (or not). Indeed, with great relief I realized that the Duke's commission was as much to prove that the idea of the wing would fail as that it could be a success. With this thought in mind I went to sleep, with a light heart, knowing that I still had time in hand to complete the fabric wing and to lead the various strings that were part of the flapping mechanism. This would be my task in the final day still to come.