Internationally famous for his artistic creations, Leonardo da Vinci was also a brilliant engineer and inventor. He was fascinated by hydraulic and solar energy as well. Back then, he imagined many devices working with optical lenses. One of his drawing : “allegories of human undertakings”, depicts the sun which rays reflect on a compass. There also a plough in the background, as well as a ribbon which stands for a symbol knowledge. Thus, Leonardo was aware of the importance of the sun in the human development. According to several sources, Leonardo has figured out a technique to weld bronze with solar energy in order to produce a huge equestrian statue dedicated to the Duc Milan Ludovic Sforza. Nevertheless, the project is stopped. The 100 tons of bronze allocated to the monument are finally used to manufacture cannons to repel the French Louis XII’s army. They finally invade the city in 1499, thus definitively making the equestrian statue project disappear for real.
