A Sketchy History Of Pencil Lead

When we say pencil lead, we mean graphite, because that’s what a pencil has inside. In this video, we find out where graphite comes from and how it gets into the middle of a pencil.

(YouTube link)

All interesting stuff, but now I want to know about the part they left out. Who’s idea was it to encase graphite in wood to make a pencil? -via The Kid Should See This
For the missing history of pencil development, Martin Veneroso suggested Brain Pickings and romojoke suggested Wikipedia, both of which are quite interesting.