Hadn't heard of it. Looks like it was removed sometime in the 90's, maybe, so it's not too likely that there would be a good video of it in action.

https://www.reddit.com/r/Seattle/comments/1xzypl/something_i...

https://imgur.com/gallery/3zwVKc3

It does seem like the kind of thing I might have been drawn into staring at for hours and/or playing around with, kind of like the marble perpetual-motion machine I remember from a Toronto museum at around the same time period.