Gaspard de Prony facts for kids
Quick facts for kids
Gaspard de Prony
|
|
|---|---|
 |
|
| Born |
Gaspard Clair François Marie Riche de Prony
July 22, 1755 Chamelet, Beaujolais, France
|
| Died | July 29, 1839 (aged 84) |
| Nationality | French |
| Known for |
|
| Scientific career | |
| Fields | |
| Institutions | École Nationale des Ponts et Chaussées |
Baron Gaspard Clair François Marie Riche de Prony (born July 22, 1755, died July 29, 1839) was a smart French mathematician and engineer. He was known for his work with hydraulics, which is the science of how liquids move and are used. He was born in Chamelet, France, and passed away in Asnières-sur-Seine, France.
Contents
Early Life and Career
Gaspard de Prony was a very important engineer in France. He became the Engineer-in-Chief at the École Nationale des Ponts et Chaussées. This was a famous school for engineers.
Creating Math Tables for France
In 1791, de Prony started a huge project. He wanted to create new logarithmic and trigonometric tables. These tables were like giant calculators made of numbers. The French government supported this work. After the French Revolution, they wanted to make all measurements the same across the country.
Why Were These Tables Needed?
These tables were meant for very exact land surveys. They were part of a bigger plan to map all of France. The tables were huge, calculating logarithms up to 200,000. Some values were calculated to an amazing 29 decimal places! De Prony knew this was more precise than needed.
How De Prony Organized the Work
De Prony was inspired by a book called Wealth of Nations. This book talked about dividing up work. He decided to split the work into three levels. He even joked that he could "manufacture logarithms as easily as one manufactures pins."
The Expert Mathematicians
The first group had five or six top mathematicians. These included famous names like Adrien-Marie Legendre. This group chose the best math formulas to use. They also decided how many decimal places to calculate.
The Planners
The second group had seven or eight "planners." These were mathematicians who had worked on similar projects before. They used the formulas from the first group to calculate key numbers. They also made templates and instructions for the next group. This group also checked all the calculations. They used a method called "differencing" to quickly spot any mistakes.
The Human Computers
The third group was the largest, with 60 to 90 "human computers." These people only needed to know basic math like addition and subtraction. Many of them were hairdressers who had lost their jobs after the French Revolution. They did the most repetitive and tiring parts of the work. They often worked from home and sent their results in. Each of these calculators could do about 700 calculations a day.
De Prony's tables were very important for French mapping.
- First, sailors needed logarithms for navigation. They used them to figure out their position at sea. The new French metric system was making old tables useless. De Prony's new tables helped sailors switch to the metric system easily.
- Second, trigonometry was needed for land surveys (cadastral measures). Accurate maps of French land were vital. These tables helped map everything, even down to property lines. Both naval power and good administration were important for France at the time.
A Monument to Calculation
De Prony wanted his project to be perfect and "the most vast... monument to calculation ever executed." However, the tables were not used for their original purpose. The new metric system changed, and the tables became outdated. Also, such extreme accuracy wasn't really needed in practice. So, the tables became more like amazing historical artifacts than everyday tools.
Changing What "Calculation" Meant
Around the early 1800s, the idea of "calculation" changed. Before, doing calculations was seen as a job for smart academics. After de Prony's project, it became linked to simpler, repetitive work. This also led to more women being hired for these computing jobs. This change was largely because of de Prony's project. It showed that many different people, with different math skills, could work together on huge calculations.
Influence on Charles Babbage
Charles Babbage is famous for inventing the first mechanical computer. He was greatly inspired by de Prony's idea of dividing up work. Babbage thought that machines could do the work of the "human computers." This would leave only the top two groups of mathematicians as humans.
Why the Tables Weren't Widely Used
In 1795, the French government made the metric system official. But they didn't include the decimal angle measurement that de Prony used. This made much of his work less useful. Because of this, funding for his project stopped. De Prony kept working until 1800, but his publisher went out of business. The tables weren't seen by the public until a century later. The government under Napoleon eventually gave up on the project.
Prony's Inventions
Gaspard de Prony also made other important contributions.
Prony's Brake
One of his key inventions was the "Prony brake" in 1821. This device was used to measure the power or torque produced by an engine. It helped engineers understand how strong an engine was.
Measuring Gravity
He was also the first to suggest using a special swinging weight, called a reversible pendulum, to measure gravity. Another scientist, Henry Kater, independently invented a similar device in 1817, which became known as the Kater's pendulum.
Prony's Estimation Method
De Prony also created a math method called "Prony estimation." This method helps convert wavy and growing curves into simpler equations. It is still used today in areas like signal processing and modeling materials.
Engineering Projects
Napoleon hired de Prony for big engineering jobs. He oversaw projects to protect the province of Ferrara from floods by the Po River. He also worked on draining and improving the Pontine Marshes. After the French monarchy was restored, he helped control the flow of the Rhône River and worked on other important projects.
Honors and Recognition
Gaspard de Prony was a member of the French Academy of Science, and later its president. He was also chosen as a foreign member of the Royal Swedish Academy of Sciences in 1810. His name is one of the 72 names written on the Eiffel Tower in Paris. There is also a street named after him, Rue de Prony, in Paris.
See also
In Spanish: Gaspard de Prony para niños
- Prony equation
- Charles Storer Storrow
