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This Proposal has been approved, and is now a Milestone
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:
Pacinotti's ring armature of direct current dynamos, 1863
Plaque citation summarizing the achievement and its significance:
An early dynamo machine equipped with a ring armature was built and described for the first time by Antonio Pacinotti at the University of Pisa, Italy in 1863. Groups of turns of the closed armature winding were regularly connected to the bars of a commutator. Antonio Pacinotti observed that the dynamo could work as a generator as well as a motor. About ten years later a generator with ring armature was reinvented and patented by Zenobe Gramme.
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: Ermanno Cardelli
IEEE Organizational Unit(s) arranging the dedication ceremony:
Unit: IEEE ITALY SECTION
Senior Officer Name: Ermanno Cardelli
IEEE section(s) monitoring the plaque(s):
IEEE Section: IEEE ITALY SECTION
IEEE Section Chair name: Ermanno Cardelli
Proposer name: Sami Barmada
Proposer email: Proposer's email masked to public
Proposer name: Marco Raugi
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):
School of Engineering, University of Pisa, L-go Lucio Lazzarino 1, 56123, Pisa, Italy Latitude 43.7209875 Longitude 10.389789899999982
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 site is the university where Antonio Pacinotti studied and operated as a Professor of Applied Physics. Here he developed and tested an early dynamo machine equipped with a ring armature. A version of the prototype of his invention is currently visible at the University of Pisa. The intended milestone plaque could be located at the headquarter of the School of Engineering, an historical building, built in the 1930s. There exists a little bas-relief reproducing the image of Antonio Pacinotti and his dynamo. The bas-relief does not contain any details except the name of the scientist. The IEEE plaque could be placed side by side to the bas-relief, giving to both a great prominence and importance.
Are the original buildings extant?
Details of the plaque mounting:
The plaque could be mounted on the wall near the entrance of the main lecture hall, placed inside the main building of the School of Engineering. How is the intended plaque site protected/secured, and in what ways is it accessible to the public? If visitors to the plaque site will need to go through security, or make an appointment, please give details as well as the contact information visitors will need in order to arrange to visit the plaque. The School of Engineering has a porter’s lodge. Anyhow, since the building contains also the classrooms for university students, the site is usually open to the public for six days/week (Monday to Friday from 8:00 am to 8:00 pm, Saturday from 8:00 am to 1:00 pm). During this time visitors are free to visit the plaque.
How is the site protected/secured, and in what ways is it accessible to the public?
Who is the present owner of the site(s)?
The present owner is the University of Pisa.
What is the historical significance of the work (its technological, scientific, or social importance)?
Antonio Pacinotti (1841-1912) learned the principles of electromagnetism in his youth and under the direction of his father, Luigi Pacinotti, Professor of Technological Physics at University of Pisa. Then, early in 1859, he began to develop and build an electromagnetic machine with transverse electromagnet which was the basis of the invention of the Direct Current generator or dynamo. Later he stopped the project because on May of the same year he volunteered, in the ongoing war as a sergeant of the 2nd Company of the Tuscany Division Military Engineers. In 1860, he returned to Pisa and after passing university exams, with the help of Giuseppe Poggiali, a technician in the Phisics Laboratory, he built and tested his machine, the first practical dc generator. The results of his experiments and a detailed description of his dynamo were published in the Italian scientific journal Nuovo Cimento in 1864. About the invention, Pacinotti wrote: "The electro-magnetic machine of which the first ideas are here recorded, was built by me in a small model; [...] This machine has only one fixed electro magnet. It works very well as a magneto-electric machine, since always gives a very intense current in one direction". In another note, dated 22 and 23 June 1860, Antonio Pacinotti wrote that the machine works well both as a motor and as a dynamo. In September, 1860, he declared that his machine with respect to other similar devices, such as the Clarke machine, has the advantage of producing direct current, with a constant rotation speed. Although other scientist attempted to build similar devices some years earlier, Pacinotti's machine was the first practical direct current dynamo because it did not produce severely isolated pulses of electric current. At the Vienna Exhibition in 1873 he presented his invention of the 1860s, and for the first time received wide credit. A medal of progress was granted Professor Pacinotti in Vienna, and other medals of honor were given him in 1881 at Paris. The Pacinotti's invention radically contributed to change electricity from a curiosity into a profitable, reliable technology. In fact, until the mid-1800s, the unique source of electric power was the Volta's battery. Unfortunately this kind of electric source was not reliable or cost effective for any regular electrical use. The combination between the dynamo and the invention of the electric light bulbs, available by 1879, allowed the “electricity revolution” both in social and industrial environments. DC generators were installed at the Pearl Street station facilities in New York City, the earliest commercial power generating plant, mainly used for electric lighting. In the same years, DC motors were introduced in some manufacturing industries to substitute the single huge steam engine, so far used to drive all the belts machines running at the same speed. This fact contributed to barely increase the productivity of the factories and most importantly to improve working conditions and safety for the workers. Antonio Pacinotti died in Pisa, on March 24, 1912. At the time of his death he was professor of technological physics at the University of Pisa, succeeding his father since 1881; he was also a senator of the kingdom of Italy.
What obstacles (technical, political, geographic) needed to be overcome?
With the idea of using a simple device called “commutator” and the ring and toothed types of armature, Antonio Pacinotti contributed to develop the first practical direct current dynamo. The devices previously investigated by other scientists were not able to be used as commercial generators since they produced severely isolated pulses of electric current or they were characterized by low efficient design.
What features set this work apart from similar achievements?
With the idea of using a simple device called “commutator” and the ring and toothed types of armature, Antonio Pacinotti contributed to develop the first practical direct current dynamo. The devices previously investigated by other scientists were not able to be used as commercial generators since they produced severely isolated pulses of electric current or they were characterized by low efficient design. Although Pacinotti tested his invention by using a permanent magnet as the source of the magnetic field, he described the operation of the machine with reference to an electro-magnet. This was a further improvement, since the use of an electromagnet as a field source allows to increase and to control the electric output.
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.
B.Bowers, A History of Electric Light and Power, P.Peregrinus, 1982, pagg 85,90,247 Il Nuovo Cimento, vol. XIX, 1864, pagg. 378-384 (see the attached english translation of the paper) http://www.fondazionegalileogalilei.it/fondo_pacinotti/strumenti_pacinotti/strumenti_p.html
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 email@example.com. Please see the Milestone Program Guidelines for more information.
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 firstname.lastname@example.org 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).