Tesla’s Egg and the battle for electricity


Nikola Tesla should be one of the most famous and celebrated men of all time, an inventor whose discoveries opened the door to electrical power, the second industrial revolution and the birth of the modern age. Yet he was overshadowed even in his own time by men such as Thomas Edison and George Westinghouse. Who was Tesla, why was he so important and why is he relatively unknown in a world that depends so heavily on his inventions?

BBC Four has had an impressive run in documentaries unearthing the fascinating history of the mundane. In Shock and Awe: The Story of Electricity, Professor Jim Al-Khalili explains the first experiments with electricity and how it developed into a source of power that would revolutionise the world.

One of the most interesting aspects of the history of electricity was the role of Nikola Tesla. I’d heard of Tesla in passing – the Tesla Coil was a dim memory from physics and had a memorable cameo in Command & Conquer: Red Alert. But I hadn’t appreciated that Tesla’s restless, inventive mind was key to harnessing the power of electricity.

It was Tesla who combined research in electricity and magnetism to produce the rotating magnetic field. This would form the basis of alternating current systems and, arguably, the foundation for the modern age.

At the 1893 Chicago Columbian Exposition, Tesla joined forces with George Westinghouse to display the ‘Egg of Columbus’, or Tesla’s Egg. By employing a two-phase alternating current source (i.e. turning one set of magnets on whilst the other set are switched off and then reversing the power), a motor can be turned (or, in this case, an ‘egg’ can spin on its axis).

This would mark an opening salvo in what would become known as the War of the Currents. Westinghouse, supported by the technical brilliance (and valuable patents) of Tesla, championed alternating current. In the opposing camp was the great American inventor, Thomas Edison, who advocated direct current.

This was neither an academic debate or a theoretical struggle – the winner would become the master of the method that would power the second industrial revolution. Westinghouse recalled the propaganda unleashed by Edison against alternating current:

“I remember Tom [Edison] telling them that direct current was like a river flowing peacefully to the sea, while alternating current was like a torrent rushing violently over a precipice. Imagine that! Why they even had a professor named Harold Brown who went around talking to audiences… and electrocuting dogs and old horses right on stage, to show how dangerous alternating current was.”

Dogs, horses and calves were not the only things to be electrocuted. One battle of the war would have been farcical if had not ended so tragically – the first use of the electric chair. This was covered in an earlier post (Shocking vocabulary) and involved Edison and Westinghouse in an unseemly battle over whose standard should be used for the execution. This time, each wanted the other to take the ‘honour’ and thus prove the deadliness of their rival’s method.

Edison was fighting a losing battle: the death knell for direct current would be heard at the Chicago Columbian Exposition and in the construction of the power plant at Niagara Falls. At the Exposition, Westinghouse had won the right to illuminate the world fair. Some 27 million people would marvel at the 100,000 incandescent lamps powered by alternating current. The ‘Great Hall of Electricity’ explained the marvellous new technology and, of course, proclaimed the victory of alternating current.

In the same year, Westinghouse was awarded the contract to build the Niagara Falls power plant. The first power from Tesla’s untested machinery would reach Buffalo on 16 November 1896. The Niagara Falls Gazette reported that day, “The turning of a switch in the big powerhouse at Niagara completed a circuit which caused the Niagara River to flow uphill.”

Soon, electric power from the great hydroelectric plant was flowing across New York State and into New York City, previously a bastion for Edison’s direct current systems. As the PBS documentary on Tesla put it:

“Broadway was ablaze with lights; the elevated, street railways, and subway system rumbled; and even the Edison systems converted to alternating current.”

Ultimately, the ease at which electricity could be transmitted by alternating current at great distances without losing too much charge was an advantage that direct current could not overcome.

In a neat piece of irony, Nikola Tesla would spend his last years as a virtual recluse living in Suite 3327 of the New Yorker Hotel. The New Yorker has been built in 1929 and had been fitted with a large direct-current power plant.

The hotel did not convert fully to alternating-current service until well to the 1960s. Thus, whilst the rest of New York City, American and the world gave way to Tesla’s logic and alternating current, his own home remained one of the few outposts of direct current.