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THE LEONARDO PROPHESY IN DETAIL

In the summer of 1492, Leonardo da Vinci was watching an Archery contest in the town of Sienna and wondered how he could harness the potential energy stored in the bow and use it to raise his flying Machine above ground.

He collected some strips of yew from which the bows are made, about half a hand wide and each five paces long and joined them end to end.

He fixed one end in the ground and lay the rest flat until the end of a field.

He then tied the free end to the shaft of a cart and with the aid of his assistants wound the sprigs of flexible yew on to the cart’s shaft.

When he reached the tethered end and the yew sprigs were fully wound around the shaft, his assistants let go of the wheels and the cart traveled to the far end unfolding his yew twig ‘Spring’.

His next step was to remove the metal rim from one of the cart wheels and to hammer it into a thin strip on an anvil while red hot.

He ended up with a metal strip a hand wide and twenty paces long.

When the ground was dry again in the Spring of 1493, he repeated the experiment of the yew blades, by winding the metal strip around the cart wheel shaft.

The going was tougher now winding the Spring, needing two men per wheel.

When his assistants let go, the cart rolled forward like a shrieking demon. He felt sure now that he could now use his invention to make his flying Machine to rise above the ground.

Try as he did, every attempt failed, as the ‘Spring’ would unwind outwards, not allowing the shaft of his flying machine to rotate enough, for his contraption to rise above the ground.

He spent many years trying to make a spring that would unwind inwards, thus giving the shaft of his flying Machine enough turns so that it would rise controllably above the ground.

By 1517, with all his attempts having failed, he wrote in his diary in his inimitable mirror image Latin:

     acinahceM acitcarp tadnecsa non iutop tu mutnatpmet roetaF

    eraitap, murtsualp erellepxe dulli, tirenev odnauq, oitar diuqib

       sedemihcrA sivan sitatsetop, marret arpus eanihcam sitnalov

                                                                .silev idneulid, siqua ni apruts

Which roughly translated says:

I must confess that try as I might, I could not come up with a practical Mechanical energy storing device, but when it comes, it will drive a cart, allow my flying machine to rise above the ground, and power a ship with an Archimedes screw in the water, doing away with sails.