Solids of Revolution
 

They're called Solids of Revolution in some places. Designed through some high falutin math that Monster could probably explain, these obese pyramids are of constant width. No, they don't look it but they are, in every direction, no matter how you measure them.

I was given several sets last Christmas. Mine are some sort of molded phenolic I guess, two sets about one inch(2.5cm) high, and several sets about 3/8 of an inch(.95cm). I'm arbitrarily calling three a set, as that's the minimum to do this demonstration.

It's eerie to watch, but with your hand on the book it's absolutely smooth as ball bearings.

http://cellar.org/2014/rockroller.gif

This is the label on the bag.

Goddamn.

That is cool as hell.

What is the practical application? Moving stones for your monolith?

For some reason, these remind me of those fork lift wheels made up of multiple, rotating 'cones' that allow the fork lift to drive sideways.

I've never seen these before. Very interesting.