 Inside this rim it performed Christopher Columbus's feat by spinning a copper egg, larger than an ostrich egg, in a rotating magnetic field causing it to stand on end on its major axis due to gyroscopic action.The display also included round copper balls that seemed to orbit around the edge similar to the way planets move.Whenever the large rotating magnetic field set up by the Egg of Columbus was turned on it impressed the public by spinning various magnetized metal balls and painted metal disks on the display table and even small disks inside vacuum bulbs placed at some distance around the Electricity Building.