Egg of Columbus

While no patent applications were submitted for this device, it has become synonymous with Tesla, mentioned in almost every biography written about him. The Egg of Columbus was also one of Tesla's exhibits at the 1893 World's Fair.

The saying goes that at a certain dinner the great explorer, Christopher Columbus, wagered some scoffers of his project to balance an egg on its end. They tried it in vain. He then took it and cracking the shell slightly by a gentle blow, made it stand upright, much to the scoffer's dismay. This trick paid off for Columbus as he was granted a meeting with Queen Isabella who agreed to fund his exposition to find the new world.

Tesla similarly wagered for a meeting with investors in 1887 seeking funding for his alternating current system and motor. This device is stated to have been created in less than 24 hours for a demonstration the following day and won Tesla the support he needed.

The device was used to illustrate his rotating magnetic field principle. A copper egg placed on a wooden table spun and stood on end when powered by AC currents creating a swirling magnetic field underneath. This captivating exhibit helped promote Tesla's system during the War of the Currents, engaging audiences and investors.