A slight quibble with the guy at the video Mu linked: to flatten a stone using just one other surface you *must* have a surface that is *known* to be flat. Just using one stone to flatten another stone is *not* guaranteed to give you a flat stone — you might just end up with two non-flat stones.
You can start with *three* non-flat surfaces and, by continually rotating the pairing, end up with three flat surfaces. Should not be too hard to find a link describing the process.
September 8th, 2013 at 4:32 pm
The tidal wave of content is making my brain hurt!!!
September 9th, 2013 at 6:27 pm
There’s only one way to get a sharp knife http://www.youtube.com/watch?v=CO7KdLZY7fQ
September 10th, 2013 at 11:51 am
A slight quibble with the guy at the video Mu linked: to flatten a stone using just one other surface you *must* have a surface that is *known* to be flat. Just using one stone to flatten another stone is *not* guaranteed to give you a flat stone — you might just end up with two non-flat stones.
You can start with *three* non-flat surfaces and, by continually rotating the pairing, end up with three flat surfaces. Should not be too hard to find a link describing the process.