The machines that helped build our world have been powered by hydraulics, a compact system of valves, hoses, and pumps that transmits forces from point to point through fluid. This basic concept of powerful force transmission through fluid provides the drive for most machines today. From the ancient Roman mastery of the aqueduct to Universal Studios, a veritable hydraulic theme park, we see how hydraulics power industry, keep planes flying, and make that 3-point-turn a U-turn.