Galileo Ferraris

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Physicist, Pioneer of Alternating Current Systems (1847–1897)
Inventor of the Induction Motor

“Father of three-phase current” — Electrotechnical Congress, Frankfurt 1891

Galileo Ferraris of Turin, Italy is one of the greatest unsung heroes of AC power systems. At one time European newspapers had stated that Ferraris’s work on the induction motor and power transmission systems was “one of the greatest inventions of any age.” He was involved in the most important early experiments in AC power distance transmission which occurred in Germany and Italy in the early 1880s. His work helped others like Mikhail Dobrovsky and C.P. Steinmetz further develop polyphase electric power. Later, in the 1890s, other electrical pioneers rose to fame and the fame of Ferraris gradually faded. One of his most notable inventions was the AC motor without a commutator (the induction motor). This efficient motor made AC power practical for many uses and launched AC power as the most popular form of electric power.

Ferraris was a scientist, not an entrepreneur. He freely invited visitors to come see his lab. American AC pioneer William Stanley testified to seeing his work on the polyphase motor first hand in 1885. Instead of patenting his work, Ferraris did the opposite — he published it to the world. That is how he revealed his greatest single invention: the induction motor, in 1888.

Ferraris was inspired by the work of previous pioneers: Walter Baily, Gaulard and Gibbs, the Ganz Company, and Ferranti. Ferraris himself became a leader and teacher of electric theory and design, leading many organizations in Italy and regarded as the foremost authority on electricity in the country. One of his students, Guido Pantaleoni, went on to work for Westinghouse and became an instrumental link for licensing patents from Europe.

Galileo Ferraris Life Timeline

• Born in Livorno Vercellese (now named Livorno Ferraris), 60km NW of Turin — 1847
• Bachelor of Mathematics and Civil Engineering from the University and Engineering School of Turin — 1869
• 1879 — Became a professor of technical physics at the Museo Industriale
• 1881 — First big exposure to the new field of electricity at the International Electrical Exhibition of Paris
• 1882 — Founded the School of Electrotechnology with Laboratory at his workplace (Museo Industriale)
• 1883 — Attended the Electrical Exhibition in Vienna, Austro-Hungary
• 1884 — Hosted the International Electrical Exhibition in Turin, Italy, where he worked with Gaulard and Gibbs transformers during a groundbreaking 40km AC transmission experiment from Lanzo Torinese to Turin
• 1885 — Discovered the rotary magnetic field
• 1885 — Conceived of the idea of the AC motor, and worked on it for the next 3 years
• 1888, April 22 — Published a paper in the Royal Academy of Sciences about the AC polyphase motor, in Turin
• 1888 — Leads a number of discoveries and writes 10 papers on electromagnetism
• 1888, December 8 — Nikola Tesla publishes his AC motor design, later leading to a court case (see below)
• 1891 — Recognized as the “Father of three-phase current” at the Congress dinner of the Frankfurt Elektrotechnical Exposition
• 1896 — Joined the Italian Electrotechnical Association
• 1897 — Death
• 1899 — Most of Ferraris’s original models and motors were destroyed in a fire (along with Volta’s original devices) at the National Electrical and Silk Products Exhibition in Como, Italy
• 1942 — The damaged remains of Ferraris’s original works were destroyed completely at the Politecnico di Torino during a World War 2 bombing

See our AC Power History page to learn about his role in the development of AC electric power, and our History of Electrification page to learn more about early sites he worked on. Touch and see his work at the Physics Museum of Sardinia.

Who Invented the Polyphase Electric Motor?

After Galileo Ferraris died in 1897, Westinghouse (with Nikola Tesla) managed to rewrite history using the US court system. A perspective by M.W., part of the Engineering Forum.

Galileo Ferraris presented his theory of a polyphase electric motor 8 months prior to Nikola Tesla applying for a patent on the same technology, yet in the 21st century Tesla has received all the credit. How is this possible? Ferraris was a scientist, not an entrepreneur — he published his results and invited strangers from around the world to come see his lab. Tesla and Westinghouse had other motives.

The court cases that followed were between competing corporations, not a direct competition between Ferraris and Tesla. Other corporations argued that Ferraris had published the polyphase motor before Tesla, so Tesla and Westinghouse could not claim patent infringement.

Court cases where Tesla had to prove he invented the motor first:

• 1901 — Westinghouse Electric Mfg. Co. vs. New England Granite Co.
• 1905 — Westinghouse vs. Dayton Fan and Motor Company

The first case, in the Circuit Court in Catskill, New York, ruled in favor of Tesla. The second, in the Circuit Court of Appeals, reversed that decision, ruling in favor of Ferraris, citing proof that a magazine had published Ferraris’s work “by which Prof. Galileo Ferraris fully described and disclosed the system covered by the patents in suit.” — Hazel, District Judge, The Federal Reporter, Volume 129, page 213.

The final decision, 1905: Ferraris officially lost recognition as the first inventor of the polyphase motor, based solely on testimony from three of Tesla’s colleagues claiming Tesla had conceived the motor in fall 1887, prior to Ferraris’s publication. Tesla claimed his prototype motor was almost completely destroyed by a fire in his New York City lab in 1895 — the only motor to survive, with no way to verify its age. Ferraris, who had died, could offer no rebuttal.

William Stanley, one of America’s earliest AC pioneers, found the dispute disturbing, writing to the Electrical Review on March 16, 1903:

“[Judges Townsend, Wallace, and Cox] after a most exhaustive and thorough trial, lasting four years, decide that Mr. Tesla failed to prove invention prior to the published description of the same invention made by Professor Ferraris, of Turin, Italy… Professor Galileo Ferraris held the chair of physics at the Academy of Sciences in Turin for many years. In Europe he is universally acknowledged to be the original inventor of the induction motor and power transmission system… All foreign scientific publications speak of the Ferraris motor, the Ferraris principle and the Ferraris system, for he invented, constructed, and described his work several years before Mr. Tesla claims to have devised it… I myself have seen the original motors, models, and drawings made by Ferraris in 1885, have personally talked with the men who saw these models in operation and heard Ferraris explain them at that date.” — Electrical Review, Volume 42, 1903, pg. 415

Stanley would know: Westinghouse hired him in 1885 to study the Gaulard and Gibbs transformers used by Ferraris in the 1884–1885 experimental AC systems at Turin, then put him in charge of building a new, better AC system — which he did in 1886 at Great Barrington.

This article represents the viewpoint of the individual author, not the publishing organization. See more articles and opinions at our Engineering Forum.

Learn More About This Electrical Pioneer

• Biography of Galileo Ferraris — a detailed article in English
• The Life of Galileo Ferraris — in Italian
• Galileo Ferraris, Wikipedia

Sources

• The Federal Reporter, District of Columbia, Court of Appeals, June–July 1904, pages 213 onward
• Biography of Galileo Ferraris, profiles.incredible-people.com
• Wizard: The Life and Times of Nikola Tesla by Marc Seifer
• The Electrical Review, Volume 42, edited by George Worthington, page 415

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