Michael Faraday cage
In the course of his research program, Faraday had a large wooden cube built, big enough to hold a person and some scientific apparatus, and had the sides completely covered with a network of conducting wires. He gives the following description of it:
I went into the cube and lived in it, and using lighted candles, electrometers, and all other tests of electrical states, I could not find the least influence upon them, or indication of anything particular given by them, though all the time the outside of the cube was powerfully charged, and large sparks and brushes were darting off from every part of its outer surface.
The results of his experiments in the cube enabled him show that electricity was in fact a force rather than an imponderable fluid, as was argued by some physicists at that time. We would now call the conducting cube he constructed a Faraday cage.