Personally, I like multiple Foucault pendulums as this demonstrates rotation and curvature. I think the part that is missing in everyone's explanation is how to

Personally, I like multiple Foucault pendulums as this demonstrates rotation and curvature. I think the part that is missing in everyone's explanation is how to prove it is a sphere and not a hemisphere. Obviously, going to the "edge" would immediately shows this is false. But I think the only way to do this without moving too much is to record lunar eclipses and do the math to figure out that you would eventually see straight edges in an eclipse if the earth was not completely spherical.