Francesco di Giorgio
He trained in painting from at Vecchietta, initially operated in Orvieto and since 1463 in Siena, where he was with subordinate decorative and constructive work, namely, employed in fortifications. In 1490 he was awarded the contract to manufacture the model for the dome for Milan Cathedral, which was also carried out in 1493 by Giovanni Antonio Amadeo.
At the siege of Naples in 1495 he is said to have made the invention of the mines. Its importance lies in its extraordinary versatility that elevates him to the forefront of the Renaissance artist, he has also left no outstanding creation. He died in 1501 in Siena and was buried there in the crypt of the Basilica dell'Osservanza. His " Trattato di architettura civile e militare " has Cesare Saluzzo (Turin, 1841) published in a processing.
In this work, many machine elements appear ( gears, worm gears, movement threaded spindles, etc.) in his catapult - or heavy-duty crane constructions.