Cool Engineering stuff of yesteryear’s.
https://www.youtube.com/watch?v=22H8M8h6Hdo
https://www.youtube.com/watch?v=Y91Zr480Tn4
https://www.youtube.com/watch?v=CwLx4L5NRU0
https://www.youtube.com/watch?v=yOApFeEgHcE
https://www.youtube.com/watch?v=th-RoJBP0Vs