he Duke, Leonardo served many positions. He served as principal engineer in the Duke’s numerous military enterprises and was active as an architect (Encarta). As a military engineer Leonardo designed artillery and planned the diversion of rivers. He also improved many inventions that were already in use such as the rope ladder. Leonardo also drew pictures of an armored tank hundreds of years ahead of its time. His concept failed because the tank was too heavy to be mobile and the hand cranks he designed were not strong enough to support such a vehicle. As a civil engineer, he designed revolving stages for pageants. As a sculptor he planned a huge monument of the Duke’s father mounted up on a leaping horse. The Horse, as it was known, was the culmination of 16 years of work. Leonardo was fascinated by horses and drew them constantly. In The Horse, Leonardo experimented with the horses' forelegs and measurements. The severe plagues in 1484 and 1485 drew his attention to town planning, and his drawings and plans for domed churches reflect his concern with architectural problems (Bookshelf). In addition he also assisted the Italian mathematician Luca Pacioli in the work Divina Proportione (1509). While in Milan Leonardo kept up his own work and studies with the possible help of apprentices and pupils, for whom he probably wrote the various texts later compiled as Treatise on Painting (1651). The most important painting of those created in the early Milan age was The Virgin of the Rocks. Leonardo worked on this piece for an extended period of time, seemingly unwilling to finish what he had begun (Encarta). It is his earliest major painting that survives in complete form. From 1495 to 1497 Leonardo labored on his masterpiece, The Last Supper, a mural in the refectory of the Monastery of Santa Maria delle Grazie, Milan. While painting The Last Supper, Leonardo rejected the fresco technique normally used for wall...
