World Columbian Exposition

The World Columbian Exposition (also called The Chicago World's Fair), a World's fair, was held in Chicago in 1893 to celebrate the 400th anniversary of Christopher Columbus's discovery of the New World. Chicago had beaten New York City, Washington, D.C. and St. Louis, Missouri for the honor of hosting the fair. The fair had a profound effect on architecture, the arts, Chicago's self image, and American industrial optimism.

Electricity at the fair

The International Exposition was held in a building which -- for the first time -- was devoted to electrical exhibits. It was an historical moment and the beginning of a revolution, as Nikola Tesla and George Westinghouse introduced the public to electrical power by providing alternating current to illuminate the Exposition. The general public observed firsthand the qualities and abilities of alternating current power. All the exhibits were from commercial enterprises. Thomas Edison, Brush, Western Electric, and Westinghouse had exhibits. General Electric Company (backed by Edison and J.P. Morgan) proposed to power the electric fair with direct current at the cost of one million dollars.

Related Topics:
Nikola Tesla - George Westinghouse - Electrical - Alternating current - Western Electric - Westinghouse - General Electric - Direct current

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Westinghouse, armed with Tesla's alternating current system, proposed to illuminate the exposition for half that price. Tesla's high-frequency high-voltage lighting produced more efficient light with quantitatively less heat. A two-phase induction motor was driven by current from the main generators to power the system. Edison tried to prevent the use of his light bulbs in Tesla's works. Westinghouse's proposal was chosen over the inferior direct current system to power the fair. General Electric banned the use of Edison's lamps in Westinghouse's plan, in retailiation for losing the bid. Westinghouse's company quickly designed a double-stopper lightbulb (sidestepping Edison's patents) and was able to light the fair.

Related Topics:
Frequency - Voltage - Motor - Generators

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The Westinghouse Company displayed several polyphase systems. The exhibits included a switchboard, polyphase generators, step-up transformers, transmission line, step-down transformers, commercial size induction motors and synchronous motors, and rotary direct current converters (including an operational railway motor). The working scaled system allowed the public a view of a system of polyphase power which could be transmitted over long distances, and be utilized, including the supply of direct current. Meters and other auxiliary devices were also present.

Related Topics:
Polyphase system - Transformer

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Tesla displayed his phosphorescent lighting, powered without wires by high-frequency fields. Tesla displayed the first practical phosphorescent lamps (a precursor to fluorescent lamps). Tesla's lighting inventions exposed to high-frequency currents would bring the gases to incandescence. Tesla also displayed the first neon lights. His innovations in this type of light emission were not regularly patented.

Related Topics:
Fluorescent lamp - Neon light

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Also among the exhibits was Tesla's demonstration, most notably the "Egg of Columbus". This device explains the principles of the rotating magnetic field and his induction motor. The Egg of Columbus consisted of a polyphase field coil underneath a plate with a copper egg positioned over the top. When the sequence of coils were energized, the magnetic field arrangement inductively created a rotation on the egg and made it stand up on end (appearing to resist gravity). On August 25, Elisha Gray introduced Tesla for a delivery of a lecture on mechanical and electrical oscillators. Tesla explained his work for efficiently increasing the work at high frequency of reciprocation. As Electrical Congress members listened, Tesla delineated mechanisms which could produce oscillations of constant periods irrespective of the pressure applied and irrespective of frictional losses and loads. He continued to explain the working mean of the production of constant period electric currents (not resorting to spark gaps or breaks), and how to produce these with mechanisms which are reliable.

Related Topics:
Egg of Columbus - August 25 - Elisha Gray - Oscillator

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The successful demonstration of alternating current lighting at the Exposition dispelled doubts about the usefulness of the polyphase alternating current system developed by Westinghouse and Tesla.

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