Chevrolet Suspension (1938): https://www.youtube.com/watch?v=ej7CRAIGXow
How Differential Steering Works (1937): https://www.youtube.com/watch?v=yYAw79386WI
How A Transmission Works (1936): https://www.youtube.com/watch?v=JOLtS4VUcvQ
And as a bonus, an explanation about transistors from 1953: https://www.youtube.com/watch?v=V9xUQWo4vN0
And here is a 1959 video from the same source about wave behavior [1].
It covers reflection from open and closed ends, superposition, standing waves and resonance, impedance mismatching, and tapered-section transformers all in a way that makes it really easy to understand.
About the Strowager Switch, which was invented by an undertaker who was fed up with the local telephone operators whom he suspected of diverting phone calls to his competitor.