Random TIL 1
Coal can be classified by its "rank", which measures carbon content and heating value. In descending rank, the rocks are called Anthracite, Bituminous, Subbituminous and Lignite (from lat. lignum = wood). Generally, the deeper, the higher the rank (Hilt's law).
I'm trying a new thing. From now on, I'll embrace my Wikipedia addiction and I'll post one random TIL somewhat regularly. The subject will be completely random (sciences, programming, geography, and more, not always from Wikipedia). Only restriction is it has to be something new I've learned and I have to have learned it at that day.
I'm tagging it all with #randomtil. So if you get fed up with this, either unfollow me or filter this tag.
