Leonardo da Vinci(1452–1519) is the best-known of these Renaissance artist-engineers. He used drawing and text together to perform thought experiments in many areas of engineering and science. These thought experiments include the design of a helicopter-like flying machine, a military tank, and a bridge. da Vinci developed the form of an engineering or scientific notebook that is used to support the process of engineering design or scientific inquiry. Figure 10 shows the design of a giant crossbow that da Vinci created.