The Michelson - Morley apparatus was built on a slab of sandstone 5 foot square by 1 foot thick which was floated in a pool of mercury. It allowed the experiment to use a huge mass for the optical table with virtually friction-less rotation of the device. The experiment was housed in a basement at the Case Western Reserve University in the mid 1880’s.
The Truth is out there. I’m not saying its Aliens—But its Aliens!