In his job application to Ludovico Sforza, Leonardo had boasted of his talent for “guiding water from one place to another.” That was, at best, an exaggeration. When he first arrived in Milan, in 1482, he had done no hydraulic engineering. But like many of his fantasy aspirations, he willed this one into reality. During his years in Milan, he dilig

With the help of the writings of Alberti and the development of mathematical perspective, the social and intellectual standing of painters was rising, and a few were becoming sought-after names.

Leonardo’s apprentices and students did not merely copy his designs. A show at the Louvre in 2012 featured paintings that students and assistants in his workshop did of his masterpieces. Many were variations that were produced alongside his original, indicating that he and his colleagues were together exploring various alternative approaches to the