U.S. NAVY BASIC MECHANISMS OF FIRE CONTROL COMPUTERS MECHANICAL COMPUTER INSTRUCTIONAL FILM 27794

Caption notes

This historical U.S. Navy training film explains how mechanical motion can represent and operate on numbers. The narration starts with values encoded in shaft rotation, then describes how gears scale motion, how cam profiles map inputs to outputs, and how a differential combines signed quantities. A rack example separates physical movement from the reported value: the pinion center moves by half the sum of the rack displacements, and a different scale lets that movement be read as their sum. The film uses a mechanical fire-control computer to connect the examples and points out that results depend on the quality of the inputs. This guide focuses on the narrated principles of mechanical computation.