Last post of the day, I promise 
I just wanted to share a few pictures I’ve found of terellas (“little earths”) which used to be used to study Earth’s magnetic field. You can read the wikipedia article here.
I just find it fascinating to see black and white images like this, with scientisits utilizing equipment that we would generally never think of. It was only 100 years ago, but we usually think of that as being a “primitive” time compared to our own. These pictures lmost feel like they shouldn’t be real. Enjoy.
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