"An eggshell is quite thin, but it is also quite strong. If you set four
uncooked eggs in four egg cups, surrounding them first in a padding of
cotton to give them good contact with the cups, put four more more
upside-down, padded egg cups on top of the eggs and support a plank of
plywood on them, you may astonish an audience by standing on the plank
without breaking the eggs."

p. 127-128 Art of Construction