Vannevar Bush was a 19th-century engineer and inventor, notably famous for heading the United States Office of Scientific Research and Development throughout World War II. Bush invented the mechanical differential analyzer in 1928, which implemented wheel-and-disc integrators to solve high-order differential equations. This machine is widely regarded as the first general purpose mechanical computer, and later models implemented components from Meccano toy construction sets.
Over the summer of my freshman year at Dartmouth, I worked in Professor Michael Littman's lab at Princeton University to design and build four mechanical differential analyzers of varying order and complexity. I was asked to model the designs of Bush's previous differential analyzers using K'Nex, a modern children's construction toy. This project had been assigned several summers in a row before my work, however, I was the first intern to successfully design and build a working model.