"In the 19th century, a device known as The Tempest Prognosticator would use leeches to ‘predict storms.’ 12 leeches were kept in a jar with a bell at the top.
If a storm were to approach, they would attempt to climb out of the jar, ringing the bell along the way."
Thanks Captn
And most of their picdumps come from bored panda. That's how meme sites work.