Everyone who has ever handled a spinning gyroscope found themselves likely mesmerized by the way it absolutely maintains its orientation even when disturbed. Much of modern technology would be impossible without them, whether space telescopes or avionics. Yet during the early 20th century a much more radical idea was proposed for gyroscopes, one that would essentially have turned entire trains into gyroscopes. This was the concept of the Gyro Monorail, with Louis Brennan being among those who built a full-sized, working prototype in 1910, with its history and fate covered in detail by [Primal Space], along with an accompanying video.
This is a companion discussion topic for the original entry at https://hackaday.com/2024/01/31/the-gyro-monorail-how-to-make-trains-better-with-a-gyroscope/