Giovanni Poleni (; 23 August 1683 – 15 November 1761) was a
Marquess
A marquess (; ) is a nobleman of high hereditary rank in various European peerages and in those of some of their former colonies. The German-language equivalent is Markgraf (margrave). A woman with the rank of a marquess or the wife (or wid ...
,
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...
,
mathematician
A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, mathematical structure, structure, space, Mathematica ...
and
antiquarian
An antiquarian or antiquary () is an aficionado or student of antiquities or things of the past. More specifically, the term is used for those who study history with particular attention to ancient artefacts, archaeological and historic si ...
.
[
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Early life
He was the son of Marquess Jacopo Poleni and studied the classics, philosophy, theology, mathematics, and physics at the School of the Somaschi Fathers
The Somaschi Fathers, also known as the Somascans and officially as the Order of Clerics Regular of Somasca (), are a Catholic Church, Catholic order of Cleric regular, Clerics Regular of Pontifical Right for men. It was founded in Italy in th ...
, Venice.
Career
He was appointed, at the age of twenty-five, professor of astronomy at Padua. In 1715 he was assigned to the chair of physics, and in 1719 he succeeded Nicholas II Bernoulli as professor of mathematics. As an expert in hydraulic engineering
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the move ...
he was charged by the Venetian Senate with the care of the waters of lower Lombardy
The Lombardy Region (; ) is an administrative regions of Italy, region of Italy that covers ; it is located in northern Italy and has a population of about 10 million people, constituting more than one-sixth of Italy's population. Lombardy is ...
and with the constructions necessary to prevent floods. He was also repeatedly called in to decide cases between sovereigns whose states were bordered by waterways.
Poleni was the first to build a calculator that used a pinwheel design. Made of wood, his ''calculating clock'' was built in 1709; he destroyed it after hearing that Anton Braun had received 10,000 Guldens for dedicating a pinwheel machine of his own design to the emperor Charles VI of Vienna. Poleni described his machine in his ''Miscellanea'' in 1709, but it was also described by Jacob Leupold in his ''Theatrum Machinarum Generale'' ("The General Theory of Machines") which was published in 1727. In 1729, he also built a tractional device that enabled logarithm
In mathematics, the logarithm of a number is the exponent by which another fixed value, the base, must be raised to produce that number. For example, the logarithm of to base is , because is to the rd power: . More generally, if , the ...
ic functions to be drawn.
Poleni's observations on the impact of falling weights (similar to Willem 's Gravesande's) led to a controversy with Samuel Clarke
Samuel Clarke (11 October 1675 – 17 May 1729) was an English philosopher and Anglican cleric. He is considered the major British figure in philosophy between John Locke and George Berkeley. Clarke's altered, Nontrinitarian revision of the 1 ...
and other Newtonians that became a part of the so-called " ''vis viva'' dispute" in the history of classical mechanics
Classical mechanics is a Theoretical physics, physical theory describing the motion of objects such as projectiles, parts of Machine (mechanical), machinery, spacecraft, planets, stars, and galaxies. The development of classical mechanics inv ...
.
His knowledge of architecture caused Benedict XIV to call him to Rome in 1748 to examine the cupola
In architecture, a cupola () is a relatively small, usually dome-like structure on top of a building often crowning a larger roof or dome. Cupolas often serve as a roof lantern to admit light and air or as a lookout.
The word derives, via Ital ...
of St. Peter's, which was rapidly disintegrating.
As part of the structural investigation of the dome he used a correctly loaded hanging chain to determine its funicular shape. He promptly indicated the repairs necessary. He also wrote a number of antiquarian
An antiquarian or antiquary () is an aficionado or student of antiquities or things of the past. More specifically, the term is used for those who study history with particular attention to ancient artefacts, archaeological and historic si ...
dissertations. In 1710 he was elected a Fellow of the Royal Society
Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the Fellows of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...
, in 1739 the French Academy of Sciences
The French Academy of Sciences (, ) is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific method, scientific research. It was at the forefron ...
made him a member and later the societies of Berlin and St. Petersburg did the same. The city of Padua elected him as magistrate, and after his death erected his statue by Canova. Venice also honoured him by striking a medal.
He married Orsola Roberti of Bassano della Grappa. A pupil of his was Giovanni Battista Suardi (1711 – 1767).
Principal works
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*''Miscellanea'' (dissertations on physics), Venice, 1709;
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* ''De castellis per quæ derivantur fluviorum latera convergentia'', Padua, 1720;
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*''Exercitationes Vitruvianæ'' Venice, 1739;
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*''Il tempio di Diana di Efeso'' (The Temple of Diana at Ephesus
Ephesus (; ; ; may ultimately derive from ) was an Ancient Greece, ancient Greek city on the coast of Ionia, in present-day Selçuk in İzmir Province, Turkey. It was built in the 10th century BC on the site of Apasa, the former Arzawan capital ...
); Venice, 1742.
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File:Poleni-1.jpg, Title page to ''De Castellis per quae derivantur fluviorum aquae habentibus latera convergentia liber'' (1718)
File:Poleni-4.jpg, First page to ''De Castellis per quae derivantur fluviorum aquae habentibus latera convergentia liber'' (1718)
File:Poleni-5.jpg, Figure from ''De Castellis per quae derivantur fluviorum aquae habentibus latera convergentia liber'' (1718)
References
Further reading
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;Attribution
*. Cites:
**''Memorie per la vita del Signor Giovanni Poleni'' (Padua, 1762);
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External links
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Guide to Giovanni Poleni, Specifications and Drawings of the Poleni Calculating Machine by Joannis Poleni 1927
at th
University of Chicago Special Collections Research Center
{{DEFAULTSORT:Poleni, G
1683 births
1761 deaths
Republic of Venice people
18th-century writers in Latin
18th-century Italian male writers
Italian antiquarians
18th-century Italian physicists
Fellows of the Royal Society
Members of the Prussian Academy of Sciences
Members of the French Academy of Sciences
Academic staff of the University of Padua