Off Topic: a historical birthday

It's official, it was 2 days ago - well, in some places of the world it's still yesterday, but at least you don't get the same posts all on one day. I'm late because I was enjoying my weekend!

12th February was the birthday of a historical scientific figure. If you can work out who authored the provided image (source), I think you deserve to click on this link for a little giggle - but only if you figure it out ;-)

Here is a modern day version of the diagram.

Happy days.