Cool and wacky inventions

[Fishmé]

[video]https://youtube.com/watch?v=/0yWjaYH_u-U?si=XfXDMgCGNjo09bOC[/video]

[rachel]

What about this marble clock?

[video]https://www.youtube.com/watch?v=_hpUnX9buR4[/video]

It's been almost a year since he posted this and it just keeps getting more elaborate. He's been working on a new marble clock that can display seconds