Leonardo lived a life filled with inspiration, but also with unhappiness. Throughout his years he went through moments of despair, but he also found glory when he was welcomed in Florence as a great painter of the day. While only a few of Leonardo's works remain intact for us to see, and while his life was long lived and sometimes filled with sadness, we are blessed with the gift of the beautiful pieces that Da Vinci left behind. The few paintings of Da Vinci's as well as the many notebooks are scattered in different places throughout the world, one of his notebooks is even owned by software tycoon, Bill Gates . While we can't all buy the actual pieces, we can still all take in a little bit of Da Vinci through art prints of his works. Many Da Vinci art prints and posters exist, and we can purchase the masterful The Last Supper , or The Mona Lisa to bring a little bit of Da Vinci into our own homes.
The fame of Da Vinci's surviving paintings has meant that he has been regarded primarily as an artist, but the thousands of surviving pages of his notebooks reveal the most eclectic and brilliant of minds. He wrote and drew on subjects including geology, anatomy (which he studied in order to paint the human form more accurately), flight, gravity and optics, often flitting from subject to subject on a single page, and writing in left-handed mirror script. He 'invented' the bicycle, airplane, helicopter, and parachute some 500 years ahead of their time.
Leonardo was employed on many different projects for Ludovico, including the preparation of floats and pageants for special occasions, designs for a dome for Milan Cathedral and a model for a huge equestrian monument to Francesco Sforza , Ludovico's predecessor. Seventy tons of bronze were set aside for casting it. The monument remained unfinished for several years, which was not unusual for Leonardo. In 1492, the clay model of the horse was completed. It surpassed in size the only two large equestrian statues of the Renaissance, Donatello's Gattamelata in Padua and Verrocchio's Bartolomeo Colleoni in Venice, and became known as the " Gran Cavallo ".  [nb 7] Leonardo began making detailed plans for its casting;  however, Michelangelo insulted Leonardo by implying that he was unable to cast it.  In November 1494, Ludovico gave the bronze to be used for cannon to defend the city from invasion by Charles VIII .