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Docket #:2018-06

This proposal has been submitted for review.

To the proposer’s knowledge, is this achievement subject to litigation? No

Is the achievement you are proposing more than 25 years old? Yes

Is the achievement you are proposing within IEEE’s designated fields as defined by IEEE Bylaw I-104.11, namely: Engineering, Computer Sciences and Information Technology, Physical Sciences, Biological and Medical Sciences, Mathematics, Technical Communications, Education, Management, and Law and Policy. Yes

Did the achievement provide a meaningful benefit for humanity? Yes

Was it of at least regional importance? Yes

Has an IEEE Organizational Unit agreed to pay for the milestone plaque(s)? Yes

Has an IEEE Organizational Unit agreed to arrange the dedication ceremony? Yes

Has the IEEE Section in which the milestone is located agreed to take responsibility for the plaque after it is dedicated? Yes

Has the owner of the site agreed to have it designated as an IEEE Milestone? Yes

Year or range of years in which the achievement occurred:


Title of the proposed milestone:

Early induction motor, 1885-1888

Plaque citation summarizing the achievement and its significance:

In 1885-1888 Galileo Ferraris, a professor at the Italian Industrial Museum (now Polytechnic) of Turin, conceived the principle of the rotating magnetic field (Ferraris' field) produced by two stationary coils with axes at right angle and supplied by two alternating currents phase-shifted by 90 degrees. He also constructed prototypes of two-phase ac motors which paved the way to three-phase industrial induction motors and to the success of three-phase electric power.

In what IEEE section(s) does it reside?

IEEE Italy Section

IEEE Organizational Unit(s) which have agreed to sponsor the Milestone:

IEEE Organizational Unit(s) paying for milestone plaque(s):

Unit: IEEE Italy Section
Senior Officer Name: Senior officer name masked to public

IEEE Organizational Unit(s) arranging the dedication ceremony:

Unit: IEEE Italy Section
Senior Officer Name: Senior officer name masked to public

IEEE section(s) monitoring the plaque(s):

IEEE Section: IEE Italy Section
IEEE Section Chair name: Section chair name masked to public

Milestone proposer(s):

Proposer name: Proposer's name masked to public
Proposer email: Proposer's email masked to public

Please note: your email address and contact information will be masked on the website for privacy reasons. Only IEEE History Center Staff will be able to view the email address.

Street address(es) and GPS coordinates of the intended milestone plaque site(s):

Energy Center House Turin Polytechnic Via Paolo Borsellino 38/16 I 10138 Torino Italy

45° 04' 13 N 07° 41' 12 E

Describe briefly the intended site(s) of the milestone plaque(s). The intended site(s) must have a direct connection with the achievement (e.g. where developed, invented, tested, demonstrated, installed, or operated, etc.). A museum where a device or example of the technology is displayed, or the university where the inventor studied, are not, in themselves, sufficient connection for a milestone plaque.

Please give the address(es) of the plaque site(s) (GPS coordinates if you have them). Also please give the details of the mounting, i.e. on the outside of the building, in the ground floor entrance hall, on a plinth on the grounds, etc. If visitors to the plaque site will need to go through security, or make an appointment, please give the contact information visitors will need. The plaque will be placed in the Energy Center House, a new building of the Turin Polytechnic. The Turin Polytechnic was established in 1906 by means of the merging of the Regio Museo Industriale Italiano (Royal Italian Industrial Museum) and the Scuola di Applicazione per Ingegneri. Media:Presentation of the Energy Center building.pdf

Are the original buildings extant?

Originally the house of the Turin Polytechnic was the building accommodating the Royal Italian Industrial Museum. Here Galileo Ferraris had his laboratory. The building was destroyed by bombs during world war 2. The new building of the Turin Polytechnic was erected in the present location in the 1950s

Details of the plaque mounting:

The plaque will be mounted on a wall in the Entrance Hall. The Hall is open to the public.

How is the site protected/secured, and in what ways is it accessible to the public?

There is a porter's lodge .

Who is the present owner of the site(s)?

The owner is the Turin Polytechnic

What is the historical significance of the work (its technological, scientific, or social importance)?

Galileo Ferraris (1847 – 1897) was an Italian engineer and scientist. After graduation in civil engineering in Turin he joined the Italian Industrial Museum ( now Technical University) of Turin where in 1877 he became professor of technical physics. His initial studies concerned mechanics, geometrical optics and theory of heat. In 1881 he took part in the International Electrical Exhibition of Paris and was attracted by the emerging field of electrical technology. Three years later he was charged to organize the electric section of the Italian General Exhibition in Turin where Lucient Goulard and John Gibbs presented their secondary generators. On that occasion Galileo Ferraris employed these new machines, later called transformers, for the first experiment of long-distance transmission of AC power from Lanzo to Turin ( 40 km, 20 kV, 2 kW, 133 Hz). One of his scientific achievements is the description of the operation of transformers using Maxwell's theory. Inspired by his studies on the optical phase difference in light waves, starting from 1885 Galileo Ferraris conceived the idea of generating a rotating magnetic field by means of alternating currents and, consequently the production of a mechanical rotation using alternating currents without commutation unlike previously done.

What obstacles (technical, political, geographic) needed to be overcome?

To the purpose of verifying his idea Galileo Ferraris built various laboratory prototypes of induction motors where a conducting cylinder was rotating under the effect of a magnetic field produced by two stationary coils with axes at right angle and supplied by two alternating currents out of phase one with another. The principle of operation of the rotating magnetic field (Ferraris' field) was explained by him in a masterly way in a memory presented at the Turin Academy of Science in March 1888. The late publication of the results of his studies in a memory written in Italian was among the reasons of a controversy with Nikola Tesla who got a patent for an induction motor in December 1888. As a matter of fact, Galileo Ferraris never patented his invention: he was a scientist, not an entrepreneur. He wrote “ I am attracted by the scientific aspect of inventions more than by the industrial one, by the intellectual achievement more than by the practical exploitation” For his small-size motor which he called “the toy”, he predicted the use in the field of instrumentation rather than of power. Nevertheless it cannot be denied that he established the basic principle of operation of the induction motor which has become the major device converting electric into mechanical power. Additionally, this type of motor, normally fed by three-phase AC current, paved the way to the success of three-phase electric power. No original motor built by Ferraris still exists because most of them were destroyed by a fire in 1899 and the remaining ones by bombs during the world war two. Galileo Ferraris was the first President of the Associazione Elettrotecnica Italiana ( Association of Italian Electrical engineers) established in 1896. He died at the age of 50.

What features set this work apart from similar achievements?

The Ferraris motor represents a remarkable step forward in electrical technology because it showed the optimal solution for the conversion of electric power in mechanical power by using AC two-phase or three-phase systems. This fact also determined the end of the dispute between direct current and alternating current in industrial applicationsin favour of the latter. As early as 1891, at the International Electrotechnical Exhibition in Frankfurt Galileo Ferraris was hailed as “the father of the three-phase system”. In Europe he is unanimously recognized as the inventor of the induction motor and the leader of AC power transmission.” Both for his contribution to electrical engineering and for his work to make the benefits of electricity widely available, Galileo Ferraris deserves to be remembered as one of the great names in our profession” (B. Bowers)

Supporting texts and citations to establish the dates, location, and importance of the achievement: Minimum of five (5), but as many as needed to support the milestone, such as patents, contemporary newspaper articles, journal articles, or chapters in scholarly books. 'Scholarly' is defined as peer-reviewed, with references, and published. You must supply the texts or excerpts themselves, not just the references. At least one of the references must be from a scholarly book or journal article. All supporting materials must be in English, or accompanied by an English translation.

1 Galileo Ferraris, Rotazioni elettrodinamiche prodotte per mezzo di correnti alternate (Electrodynamic rotations by means of alternating currents), memory read at Accademia delle Scienze, Torino, March 1888 in Opere di Galileo Ferraris, Hoepli, Milano,1902 vol I pp 333-348

2.Silvanus P. Thompson, A letter to Galileo Ferraris,25 October 1896

3. Percy Dunsheat, A History of Electric Power Engineering, The MIT Press, 1962, p. 188

4.Brian Bowers, A History of Electric Light & Power, Peter Peregrinus, 1982, p. 255

5.Brian Bowers, Galileo Ferraris and Alternating Current, IEEE Proc, vol. 89, n.5, May 2001, pp. 790-792

6. M. Mitolo, M.Tartaglia, Galileo Ferraris: A Life Dedicated to the Electrical Sciences, IEEE Industry Appl. Magazine, 2016, pp 8-11

Supporting materials (supported formats: GIF, JPEG, PNG, PDF, DOC): All supporting materials must be in English, or if not in English, accompanied by an English translation. You must supply the texts or excerpts themselves, not just the references. For documents that are copyright-encumbered, or which you do not have rights to post, email the documents themselves to Please see the Milestone Program Guidelines for more information.

The supporting material is also provided in the transmisson letter sent by e-mail together with the Support letter and the Owner letter.

Please email a jpeg or PDF a letter in English, or with English translation, from the site owner(s) giving permission to place IEEE milestone plaque on the property, and a letter (or forwarded email) from the appropriate Section Chair supporting the Milestone application to with the subject line "Attention: Milestone Administrator." Note that there are multiple texts of the letter depending on whether an IEEE organizational unit other than the section will be paying for the plaque(s).