Henry Philibert Gaspard Darcy (June 10, 1803 – January 3, 1858) was a
FrenchFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
engineerEngineers are concerned with developing economical and safe solutions to practical problems, by applying mathematics and scientific knowledge while considering technical constraints. The term is derived from the Latin root "ingenium," meaning "cleverness"...
who made several important contributions to
hydraulicsHydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
.
He was born in
DijonDijon is a city in eastern France, the capital of the Côte-d'Or département and of the Bourgogne region. Dijon is the historical capital of the province of Burgundy. Population : 150,800 for the commune; 236,953 for the greater Dijon area....
, France; despite his father's death in 1817 when he was 14, his mother was able to borrow money to pay for his tutors. In 1821 he enrolled at the
École PolytechniqueThe École Polytechnique is the foremost French engineering school. Known for its extremely competitive entrance exam, it produces graduates that occupy outstanding positions in industry and research...
(Polytechnic School) in
ParisParis is the capital of France and the country's most populous city. It is situated on the river Seine, in northern France, at the heart of the Île-de-France region...
, and transferred two years later to the
École des Ponts et ChausséesFounded in 1747, the École nationale des ponts et chaussées , often referred to as les Ponts, is the world's oldest civil engineering school. It remains to this day one of the most prestigious French Grandes Écoles of engineering.It is headquartered in Marne-la-Vallée...
(School of Bridges and Roads), which lead to employment in the
Corps of Bridges and RoadsThe Corps of Bridges is a great technical corps of the French state. It is formed of the State Engineers of the Bridges.People entering the Corps are educated at the École Nationale des Ponts et Chaussées...
.
Henry met an English woman, Henriette Carey, whose family had been living in Dijon, and married her in 1828.
As a member of the Corps, he built an impressive pressurized water distribution system in Dijon following the failure of attempts to supply adequate fresh water by drilling wells.
Henry Philibert Gaspard Darcy (June 10, 1803 – January 3, 1858) was a
FrenchFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
engineerEngineers are concerned with developing economical and safe solutions to practical problems, by applying mathematics and scientific knowledge while considering technical constraints. The term is derived from the Latin root "ingenium," meaning "cleverness"...
who made several important contributions to
hydraulicsHydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
.
Biography
He was born in
DijonDijon is a city in eastern France, the capital of the Côte-d'Or département and of the Bourgogne region. Dijon is the historical capital of the province of Burgundy. Population : 150,800 for the commune; 236,953 for the greater Dijon area....
, France; despite his father's death in 1817 when he was 14, his mother was able to borrow money to pay for his tutors. In 1821 he enrolled at the
École PolytechniqueThe École Polytechnique is the foremost French engineering school. Known for its extremely competitive entrance exam, it produces graduates that occupy outstanding positions in industry and research...
(Polytechnic School) in
ParisParis is the capital of France and the country's most populous city. It is situated on the river Seine, in northern France, at the heart of the Île-de-France region...
, and transferred two years later to the
École des Ponts et ChausséesFounded in 1747, the École nationale des ponts et chaussées , often referred to as les Ponts, is the world's oldest civil engineering school. It remains to this day one of the most prestigious French Grandes Écoles of engineering.It is headquartered in Marne-la-Vallée...
(School of Bridges and Roads), which lead to employment in the
Corps of Bridges and RoadsThe Corps of Bridges is a great technical corps of the French state. It is formed of the State Engineers of the Bridges.People entering the Corps are educated at the École Nationale des Ponts et Chaussées...
.
Henry met an English woman, Henriette Carey, whose family had been living in Dijon, and married her in 1828.
As a member of the Corps, he built an impressive pressurized water distribution system in Dijon following the failure of attempts to supply adequate fresh water by drilling wells. The system carried water from Rosoir Spring 12.7 km away through a covered
aqueductAn aqueduct is a water supply or navigable channel constructed to convey water. In modern engineering, the term is used for any system of pipes, ditches, canals, tunnels, and other structures used for this purpose....
to reservoirs near the city, which then fed into a network of 28,000 meters of pressurized pipes delivering water to much of the city. The system was fully closed and pressurized by gravity, and thus required no filters or pumps. He was also involved in many other public works in and around Dijon, as well as in the politics of the Dijon city government.
During this period he modified the
Prony equationThe Prony equation is a historically important equation in hydraulics, used to calculate the head loss due to friction within a given run of pipe...
for calculating head loss due to friction, which after further modification by
Julius WeisbachJulius Ludwig Weisbach was a German mathematician and engineer.-Life and work:Weisbach studied at the Bergakademie in Freiberg from 1822 - 1826...
would become the well-known Darcy–Weisbach equation still in use today.
In 1848 he became Chief Engineer for the
département Côte-d'OrCôte-d'Or is a department in the eastern part of France.- History :Côte-d'Or is one of the original 83 departments created during the French Revolution on March 4, 1790. It was formed from part of the former province of Burgundy.- Geography :...
(of which Dijon is the capital). Soon thereafter he left Dijon due to political pressure, but was promoted to Chief Director for Water and Pavements and took up office in Paris. While in that position, he was able to focus more on his hydraulics research, especially on flow and friction losses in pipes. During this period he improved the design of the
Pitot tubeA pitot tube is a pressure measurement instrument used to measure fluid flow velocity. The pitot tube was invented by the French engineer Henri Pitot in the early 1700s and was modified to its modern form in the mid 1800s by French scientist Henry Darcy...
, into essentially the form used today.
He resigned his post in 1855 due to poor health, but was permitted to continue his research in Dijon. In 1855 and 1856 he conducted column experiments that established what has become known as
Darcy's lawIn fluid dynamics and hydrology, Darcy's law is a phenomenologically derived constitutive equation that describes the flow of a fluid through a porous medium. The law was formulated by Henry Darcy based on the results of experiments on the flow of water through beds of sand...
; initially developed to describe flow through sands, it has since been generalized to a variety of situations and is in widespread use today. The
unitA measurement unit is a scalar quantity, defined and adopted by convention, with which any other quantity of the same kind can be compared to express the ratio of the two quantities as a number....
of fluid
permeabilityPermeability in fluid mechanics and the earth sciences is a measure of the ability of a porous material to transmit fluids.- Units :...
,
darcyA darcy and millidarcies are units of permeability, named after Henry Darcy. They are not SI units, but they are widely used in petroleum engineering and geology. Like other measures of permeability, a darcy has the same units as area.-Definition:Permeability measures the ability of fluids to...
, is named in honor of his work.
He died of
pneumoniaPneumonia is an inflammatory illness of the lung. Frequently, it is described as lung parenchyma/alveolar inflammation and abnormal alveolar filling with fluid ....
while on a trip to Paris in 1858, and is buried in Cimetière de Dijon (formerly known as Péjoces) in Dijon.
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