In the immediate postwar era, when automatic transmissions were still somewhat unusual and mysterious, the U.S. Army used its significant training skills to teach the troops about how spinning oil between two sets of paddles can move a truck.

This vintage-1953 clip clearly explains what goes on within the shell of a torque converter and how physical forces combine to transfer motion, going from tinted liquids being sloshed around in transparent casings through serious lessons in fluid dynamics and vector addition. The production values are a bit dated — the government must have spent several hundred of your grandparents' tax dollars to prepare the exhibits, and we wonder how many readers under twenty-five have ever seen a pipe cleaner in real life — but the film's ability to get its educational points across as well as it does remains remarkable in this clutter-over-content age of PowerPoint and Quicktime.