Baron Gaspard Clair François Marie Riche de Prony (22 July 1755 – 29 July 1839) was a French
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, structure, space, models, and change.
History
On ...
and
engineer
Engineers, as practitioners of engineering, are professionals who invent, design, analyze, build and test machines, complex systems, structures, gadgets and materials to fulfill functional objectives and requirements while considering the limit ...
, who worked on
hydraulics
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counte ...
. He was born at
Chamelet
Chamelet () is a commune in the Rhône department in eastern France.
See also
Communes of the Rhône department
The following is a list of the 208 communes of the Rhône department of France. This list does not includes the Lyon Metropolis ...
,
Beaujolais
Beaujolais ( , ) is a French ''Appellation d'Origine Contrôlée'' (AOC) wine generally made of the Gamay grape, which has a thin skin and is low in tannins. Like most AOC wines they are not labeled varietally. Whites from the region, which mak ...
,
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
and died in
Asnières-sur-Seine
Asnières-sur-Seine () is a commune in the Hauts-de-Seine department and Île-de-France region of north-central France. It lies on the left bank of the river Seine, some eight kilometres from the centre of Paris in the north-western suburbs of ...
,
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
.
Education and early works
He was Engineer-in-Chief of the
École Nationale des Ponts et Chaussées
École may refer to:
* an elementary school in the French educational stages normally followed by secondary education establishments (collège and lycée)
* École (river), a tributary of the Seine flowing in région Île-de-France
* École, Savoi ...
.
The trigonometric and logarithmic tables of the cadastre
In 1791, de Prony embarked on the task of producing
logarithm
In mathematics, the logarithm is the inverse function to exponentiation. That means the logarithm of a number to the base is the exponent to which must be raised, to produce . For example, since , the ''logarithm base'' 10 of ...
ic and
trigonometric
Trigonometry () is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. ...
tables for the French Cadastre. The effort was sanctioned by the
French National Assembly, which, after the
French Revolution
The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in coup of 18 Brumaire, November 1799. Many of its ...
wanted to bring uniformity to the multiple measurements and standards used throughout the nation. In particular, his tables were intended for precise land surveys, as part of a greater cadastre effort. The tables were vast, calculating logarithms from 1 to 200,000, with values calculated to between fourteen and twenty-nine decimal places, (which de Prony recognized was excessively precise).
Inspired by
Adam Smith's ''
Wealth of Nations
''An Inquiry into the Nature and Causes of the Wealth of Nations'', generally referred to by its shortened title ''The Wealth of Nations'', is the ''magnum opus'' of the Scottish economist and moral philosopher Adam Smith. First published in 1 ...
'', de Prony
divided up the labor into three levels, bragging that he "could manufacture logarithms as easily as one manufactures pins."
[Grier, David Alan (2005) ''When Computers Were Human'', ]Princeton University Press
Princeton University Press is an independent publisher with close connections to Princeton University. Its mission is to disseminate scholarship within academia and society at large.
The press was founded by Whitney Darrow, with the financia ...
The first level consisted of five or six high-ranking mathematicians with sophisticated analytical skills, including
Adrien-Marie Legendre
Adrien-Marie Legendre (; ; 18 September 1752 – 9 January 1833) was a French mathematician who made numerous contributions to mathematics. Well-known and important concepts such as the Legendre polynomials and Legendre transformation are name ...
and
Lazare Carnot. This group chose the analytical formulas most suited to evaluation by numerical methods, and specified the number of decimals and the numerical range the tables were to cover.
The second group of lesser mathematicians, seven or eight in number, were known as the "planners" and had previous experience as computers in the cadastre, mainly with experience having to do with practical mathematics.
The planners combined analytical and computational skills, with this group calculating the pivotal values using the formulas provided and the sets of starting differences. They also prepared
templates for the human computers, and the first worked row of calculations, as well as the instructions for the computers to carry the sequence to completion. Finally, this group was tasked with verifying all the calculations made by the human computers. Since recalculating every value would have nullified the use of the lowest level computers since their tasks would have been completely repeated, the planners used a method knows as "
differencing
In statistics and econometrics, and in particular in time series analysis, an autoregressive integrated moving average (ARIMA) model is a generalization of an autoregressive moving average (ARMA) model. Both of these models are fitted to time ...
," where they compared adjacent values in the tables, checking for any discrepancies.
The third group consisted of sixty to ninety
human computers. These had no more than a rudimentary knowledge of arithmetic and carried out the most laborious and repetitive part of the process. Many were out-of-work hairdressers, because, with the guillotining of the aristocracy, the hairdressing trade, which had tended the elaborate hairstyles of the elite, was in recession.
[Due to their lack of experience, they only had to calculate simple problems of addition and subtraction. In addition, this group did not operate under a factory-like model, instead opting to work from home, sending their results and receiving their new tasks from the planners in a non-centralized manner. These calculators could produce an average of around 700 calculations a day.]
Importance for mapping
The tables developed by de Prony's team were doubly important for French metric cartography
Cartography (; from grc, χάρτης , "papyrus, sheet of paper, map"; and , "write") is the study and practice of making and using maps. Combining science, aesthetics and technique, cartography builds on the premise that reality (or an i ...
. Firstly, at the time, sailors needed logarithms for math pertaining to spherical geometry, because this was needed to quickly and accurately position
Position often refers to:
* Position (geometry), the spatial location (rather than orientation) of an entity
* Position, a job or occupation
Position may also refer to:
Games and recreation
* Position (poker), location relative to the dealer
* ...
themselves to guarantee safe and efficient travel across the seas. However, the implementation of the new French Revolutionary metric system
The metric system is a system of measurement that succeeded the decimalised system based on the metre that had been introduced in France in the 1790s. The historical development of these systems culminated in the definition of the Interna ...
would make the old logarithmic tables would be obsolete, and French sailors would be unwilling to switch measurement systems since it would have rendered positional calculations significantly more difficult and less precise. Thus, de Prony, by making new logarithmic tables for the new metric system, would have facilitated the transition, enabling sailors to adopt the system. The second key element was that trigonometric values were needed for cadastral measures. Thus, for accurate mapping of the French territory and its subdivisions all the way down to the lowest levels of property ownership, de Prony needed to complete the trigonometric tables. These were both seen as crucial for Revolutionary pride considering the importance of naval prowess at the time and the need for administrative efficiency.
Enlightenment calculations
According to Prony, the project was to leave "nothing to desire with respect to exactitude" and to be "the most vast... monument to calculation ever executed or even conceived." The tables were not used for their original purpose of bringing consistent standards for measurement, as the entire cadastre project saw delays in establishing both new measurement units as well as budget cuts. In particular, these tables, which were designed for the decimal division of circles and time, turned out to be obsolete after the French had changed their measurement system. Moreover, there was no practical use for the full extent of de Prony's calculation's accuracy. Hence, these tables became more of artifacts and monuments to Enlightenment rather than objects of practical use.
Influence on the meaning of calculation
By the turn of the 19th century, there was a shift in the meaning of calculation. The talented 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, structure, space, models, and change.
History
On ...
s and other intellectuals who produced creative and abstract ideas were regarded separately from those who were able to perform tedious and repetitive computations. Before the 19th century, calculation was regarded as a task for the academics, while afterwards, calculations were associated with unskilled laborers. This was accompanied by a shift in gender roles as well, as women, who were usually underrepresented in mathematics at the time, were hired to perform extensive computations for the tables as well as other computational government projects until the end of World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
. This shift in the interpretation of calculation was largely due to de Prony's calculation project during the French Revolution
The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in coup of 18 Brumaire, November 1799. Many of its ...
.[ This project was able to unite people from many different walks of life as well as mathematical abilities (in the traditional sense) and hence changed the meaning of calculation from intelligence into unskilled labor.][
]
Mechanizing calculation
Prony was able to have artisans (workers who excelled in mechanical arts that require intelligence) work along with mathematicians to perform the calculations. Prony noted a few interesting observations about this new dynamic. First, it was fascinating to see so many different people work on the same problem. Second, he realized that even the ones with the least intellectual ability were able to perform these computations with astonishingly few errors. Prony saw this entire system as a collection of human computers working together as a whole - a machine governed by hierarchical principles of the division of labor. In fact, Prony may have begun to amend his notion of intelligence, which he began to use to evaluate the system as a whole, rather than evaluating the intelligence of its constituents.[
]
Influence on Charles Babbage
Charles Babbage, credited with inventing the first mechanical computer
A mechanical computer is a computer built from mechanical components such as levers and gears rather than electronic components. The most common examples are adding machines and mechanical counters, which use the turning of gears to increment out ...
, was inspired by de Prony's take on Smith's division of labor. He agreed with the three tiered system, but Babbage was seized by the idea that the labours of the unskilled computers could be taken over completely by machinery. This would keep only the two highest groups human, and also would transform the role of the planners into a maintenance group for the machine.
Failure of the tables to be popularly implemented
The French Revolutionary government passed the law that made the metric system the official measurement system in 1795, but they did not include the decimal angle measurement, making much of de Prony's work worthless. This also meant that the funding needed for de Prony to finish and publish his tables dried up. De Prony continued his work until 1800, but because his publisher went bankrupt, the work was not seen by the public eye until the first excerpt of the table was published a century later. The Napoleon
Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who ...
ic government abandoned the project, before abandoning the metric system entirely in 1812 dooming de Prony's work.
Prony's brake
One of de Prony's important scientific inventions was the "brake" which he invented in 1821 to measure the torque produced by an engine.
He also was first to propose using a reversible pendulum to measure gravity
In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...
, which was independently invented in 1817 by Henry Kater
Henry Kater FRS, FRAS (16 April 1777 – 26 April 1835) was a British physicist of German descent.
Early life
He was born at Bristol. At first he intended to study law; but he gave up the idea on his father's death in 1794. He entered the a ...
and became known as the Kater's pendulum
A Kater's pendulum is a reversible free swinging pendulum invented by British physicist and army captain Henry Kater in 1817 for use as a gravimeter instrument to measure the local acceleration of gravity. Its advantage is that, unlike previous ...
.
Prony's estimation method
Prony created a method of converting sinusoidal and exponential curves into a systems of linear equations. Prony estimation is used extensively in signal processing and finite element modelling of non linear materials.
Engineering projects
Prony was employed by Napoleon
Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who ...
to superintend the engineering operations for protecting the province of Ferrara
The province of Ferrara ( it, provincia di Ferrara; egl, pruvîncia ad Fràra) is a province in the region of Emilia-Romagna, Italy. Its provincial capital is the city Ferrara. As of 2016, it has a population of 354,238 inhabitants over an area ...
against the inundations of the Po and for draining and improving the Pontine Marshes
250px, Lake Fogliano, a coastal lagoon in the Pontine Plain
The Pontine Marshes (, also ; it, Agro Pontino , formerly also ''Paludi Pontine''; la, Pomptinus Ager by Titus Livius, ''Pomptina Palus'' (singular) and ''Pomptinae Paludes'' (plu ...
. After the Restoration he was likewise engaged in regulating the course of the Rhône
The Rhône ( , ; wae, Rotten ; frp, Rôno ; oc, Ròse ) is a major river in France and Switzerland, rising in the Alps and flowing west and south through Lake Geneva and southeastern France before discharging into the Mediterranean Sea. At Ar ...
, and in several other important works.
Distinctions
Prony was a member, and eventually president, of the French Academy of Science
The French Academy of Sciences (French: ''Académie des 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 research. It was at t ...
. He was also elected a foreign member of the Royal Swedish Academy of Sciences in 1810. His name is one of the 72 names inscribed on the Eiffel Tower. A street, Rue de Prony, in the 17th arrondissement of Paris
The 17th arrondissement of Paris (''XVIIe arrondissement'') is one of the 20 arrondissements of the capital city of France. In spoken French, it is referred to as ''le dix-septième'' (; "the seventeenth").
The arrondissement, known as Batignol ...
is named after him.
See also
* Prony equation
* Charles Storer Storrow
References
Notes
Citations
External links
*
*
Prony Estimation
{{DEFAULTSORT:Prony, Gaspard De
1755 births
1839 deaths
People from Rhône (department)
Barons of the First French Empire
Members of the Chamber of Peers of the July Monarchy
French engineers
Members of the Royal Swedish Academy of Sciences
Officers of the French Academy of Sciences
Foreign Members of the Royal Society
18th-century French mathematicians
19th-century French mathematicians
Commandeurs of the Légion d'honneur
Burials at Père Lachaise Cemetery