Henry P. G. Darcy and Other Pioneers in Hydraulics

Henry Darcy's first name is commonly spelled Henri, while his last name sometimes appears as d'Arcy. Original source material shows that the correct spelling is, "Henry Darcy". The "Henry" spelling was his from birth, while the "Darcy" spelling was adopted in his youth and kept throughout his life.

Henry P. G. Darcy is known for his achievements in engineering and contributions to his birthplace of Dijon, France. His descendant, Henry Darcy, the fifth person to carry the name, provides a family perceptive of his illustrious relative. In addition to biographical material, each of the other Henry's is described. Finally, excerpts from several letters from Darcy to Henry Bazin are used to show Darcy's modesty, humor and finesse. The complete paper is presented in both French and an English translation.

Starting in 1856 Henry Darcy, with the assistance of Henry Bazin, published four works that show various forms of an improved Pitot tube design. Although Henri Pitot had invented the device in 1732, theoretical and design weaknesses had kept it little more than a scientific toy. Darcy's improved instruments provided accurate and easy measurements of point velocity for the first time, which allowed advances in open channel and pipe flow hydraulics. His final design for the instrument tip is reflected today in all of our modern instruments. A reproduction of Darcy's published 1858 design was completed and shown to work as reported. Darcy's contribution to the development of the device equaled or exceeded Pitot's initial work, thus making it appropriate to refer to the modern instrument as the "Pitot-Darcy tube".

Despite a relatively short life, Henry Darcy (1803–1858) was able to leave an unforgettable legacy of engineering activity, as well as research contributions in hydraulics. His major findings are well known worldwide: The basic law for groundwater flow, the flow resistance formula for pipes and improvements to the Pitot tube. The present paper focuses on the pipe flow experiments, which were conducted by Darcy at Chaillot in Paris from August 3, 1849 to October 27, 1850. At that time Darcy was in charge as Chief Engineer of the municipal service of Paris. Details of his experimental research, along with a lucid presentation of the state of the art in pipe flow resistance formulas, may be found in his wonderful "Mémoire", submitted by Darcy to Académie des Sciences in June 1854 and published in 1858.

Henry Darcy is best known for his empirical law on fluid flow through porous media that he published as an appendix to his book Les Fontaines publiques de la ville de Dijon. Darcy had built a water supply system for Dijon in 1840, and in 1856, shortly before his death, he wrote the book to guide other engineers in constructing similar projects. This recent English translation of Darcy's 650-page book provides previously unavailable information on the context for his experiments on water flow through sand, his approach to solving problems of water distribution, a new field at that time, and his views on the humanitarian value of this project. The book contains 4 parts and an appendix. Part one is a description of the historical water situation of Dijon and attempts to provide water for the city. Part two discusses the construction of the aqueduct and the internal distribution system. Part three presents experiments that Darcy conducted on the aqueduct and distribution system. Part four discusses the expropriation of the springs, which belonged to a nearby village, and purchase of the property under which the aqueduct would be built. The appendix contains eight sections on such topics as the water supply systems of London and major French cities, artificial and natural filtration of river water, Darcy's Law, and pipe making. A separate 28-plate atlas includes drawings of the components of the Dijon water supply system, the Pitot tube, and the apparatus Darcy used for his experiments on water flow though sand.

Henry Darcy (1803–1858), engineer, designer of Dijon's water system, renowned researcher who provided the basis for both Darcy's Law and the Darcy-Weisbach equation, and initiator of the open channel research program completed by Henry Bazin (1829–1917), is being commemorated on the bi-centennial of his birth. This paper reviews his abilities by providing an original English translation of an obituary by Girard de Caudemberg, an intimate friend and colleague of Darcy's. Historians and engineers have largely overlooked Caudemberg's obituary. The story of the gold medal presented to Darcy for his services to the city of Dijon is also reported here, as well as personal observations.

Darcy's Law (1856) was the fourth of the famous nineteenth-century "Laws" of transport. It followed Fourier's Law (1822) for heat transport, Ohm's Law (1827) for the transport of electric charge and Fick's Law (1855) for the transport of dissolved chemicals. All these linear, homogeneous "laws" are energy dissipation equations, relating driving forces to their (gut-feeling) conjugated fluxes. In a natural porous body, such as a soil, all these transport processes usually occur simultaneously. Starting with the Gibbs (1876) equation, one can develop an expression for the total dissipation of energy in such bodies. Products of the driving forces and their conjugated fluxes appear as separate "blobs" of energy dissipation. It was Onsager (1931), who postulated that if one sets every flux appearing in the dissipation equation as a linear homogeneous function of each of the driving forces appearing in that same equation, one finds that the matrix of phenomenological coefficients is symmetrical. The equality of the cross-diagonal coefficients is known as Onsager's Reciprocal Relations. For this work Onsager received the Nobel Prize for chemistry in 1968. Within this whole framework of transport equations, Darcy's Law plays a central role, and, in the presence of driving forces other than the gradient of the hydraulic head, it is augmented by terms accounting for (capillary) osmosis, electro-osmosis and thermo-osmosis. Simultaneously all other fluxes now contain a term for which the driving force is the gradient of the hydraulic head: reverse osmosis (salt sieving), streaming current and heat filtration, respectively. The Philip and De Vries (1957) theory of simultaneous heat and water transport in soils is not founded in thermodynamics, and the Onsager Reciprocal Relations are lost. The misunderstanding of coupled transport has lead some researchers to erroneously conclude that their observations are "non-Darcian". It can be shown that a linear coupled transport process, when "built" into the linear Darcy equation, turns the latter non-linear.

Henry Darcy, in an appendix of his work "Les Fontaines Publiques de la Ville de Dijon", described the law governing the flow of water through a saturated sand filter. In this law, flow velocity is correlated to hydraulic gradient by means of a linear proportionality constant K, defined as "permeability" (perméabilité). In using this terminology, Darcy apparently followed the practice of hydraulic engineers of his time. Indeed, the permeability concept formulated by Darcy is known today as hydraulic conductivity, a flow parameter describing both the physical properties of the porous medium and the characteristics of the fluid. Only in the 1950s did M. K. Hubbert provide a complete theoretical foundation to Darcy's empirical expression, deriving it from the general Navier-Stokes equations. It is important to remember that Darcy's law was already utilized in many technical fields, and especially in the petroleum industry. In the petroleum industry Darcy's law is formulated in terms of pressure gradient and generalized for oil and gas flow, which led to the concept of multiphase flow. This was accomplished by separating the properties of the rock from that of the fluid by manipulating the proportionality constant K, thereby obtaining a "generalized" law. By doing so, permeability becomes a property of the porous media, dictated by pore geometry alone. The origin of the generalization of Darcy's law can be traced back to the work of American geoscientists at the end of the 1920s. The present paper proposes to establish when and by whom Darcy's law was first generalized and made suitable for petroleum reservoir engineering. In particular, the paper retraces some historical developments of the permeability concept by reviewing the earliest studies that contributed to the popularization of the generalized form of Darcy's law for fluid flow other than water.

The recognition of Henry Bazin (1829–1917) as being one of the outstanding experimenters in hydraulics of the 19th century was founded by his 1865 report Recherches Hydrauliques. This paper presents the main findings of that historically important work including the fundamental results on uniform flow, open channel velocity distributions, gradually varied free surface profiles and waves. The latter are of particular interest because the solitary wave, previously observed by the Englishman Russell, was reexamined as well as wave breaking and surge formation due to a sudden blockage of flow. Other topics addressed are the story about the Darcy and Bazin uniform flow formula, and the reason why others that used the Bazin data sets produce formulas that are still in use. Engravings from the original 1865 report and photos from a recent visit to the canal site illustrate this note on a historically outstanding contribution to open channel hydraulics.

Between 1967 and 1991, Dr. G. Garbrecht and collaborators investigated ancient hydraulic structures in the Eastern Mediterranean region. Four of these investigations are summarized herein. The summaries primarily focus on the description of hydraulic structures and the interpretation of their functionality and associated water management operations. Also, organizational aspects of the investigations and examples of the great value of the interdisciplinary approach to the discovery and interpretation of findings are presented. The investigations uncovered, even by today's standards, bold designs and planning of water resources systems, technical brilliance, grandiose architecture, and high-quality craftsmanship in the construction of the structures. It may be rightfully claimed that this work led by Dr. G. Garbrecht did not only increase our knowledge in the field of water resources development in antiquity, but also emphasized the absolute necessity of a real interdisciplinary approach in archaeological research.

Hans Albert Einstein (1904–1973) might have remained one of countless civil engineers whose work, although locally important, had little impact on the world as a whole. His career as a structural engineer in Germany in the late 1920s started in that manner. However, his trenchant independence of spirit and famous father, Albert Einstein, pulled him from this position and launched him into a productive career as researcher and educator fascinated with the mechanics of bed-sediment movement and water flow in rivers. Hans Albert Einstein made several milestone contributions, including the formulation of the first comprehensive method relating rates of bed-sediment movement and water flow.

Over the span of nearly half a century, Victor L. Streeter made significant contributions in fluid mechanics and applied hydraulics. He authored several popular textbooks and numerous technical publications. In this presentation we will first chronicle his career and then recount his efforts and lasting impact in the fields of hydraulics and fluid transients.

This paper reviews the career of Carl E. Kindsvater who founded the Hydraulics Laboratory at Georgia Institute of Technology. Kindsvater was the recipient of two ASCE Norman medals, the ASCE Collingwood Prize, the Rickey Medal, the Julian Hinds Award, and was a recognized authority on open-channel flow. He is especially known internationally for seminal work on weirs, flow over highway embankments, flow through bridge openings, and hydraulic jumps in sloping channels. Photos of equipment and various experiments reveal his procedures and methods.

Floyd Nagler, the founding director of the Iowa Institute of Hydraulic Research (IIHR, now IIHR-Hydroscience & Engineering), was granted a brief 13 years to leave his imprint on this fledgling institute. Yet in that period, he managed to construct a substantial physical research structure, establish an innovative administrative scheme, and bring considerable stability to IIHR by embracing governmental substations that brought in research projects and financial support. Nagler also imbued IIHR with his spirit of enthusiasm and energy. In these many ways, he laid the groundwork for an institute that would become world-renowned for its contributions to hydraulic education and research, and which continues to reflect the diversity of subject matter and approach modeled by its colorful and multi-talented founder.

During the late 1800s and early 1900s, improvements in groundwater-pumping equipment significantly changed the lives of western farmers. These improvements also contributed to a higher standard of living and growth of the agricultural economy of the western United States. Without groundwater irrigation, agriculture was at the mercy of the seasons. Using groundwater, farmers had less to fear from droughts and seasonal variations in surface water. Better groundwater-pumping equipment also enabled farmers to increase the amount of land they could farm, increasing their profits. The invention of self-regulating windmills and other pumping machines revolutionized farming, especially in arid areas of the Western United States. The wind-powered devices, which pumped at limited and uneven rates, eventually gave way to pumps powered by carbon-based fuels. In the late 1800s, rapid improvements in mechanical devices led to more efficient oil- and gasoline-powered equipment that could lift and distribute ever-greater quantities of groundwater from greater depths to irrigate more acreage. An oil- or gasoline-powered pump could be left unattended for hours, enabling a farmer to oversee more acreage. The development of line-shaft turbine pumps and right-angle gear drives further advanced the use of deep groundwater for irrigation. By the early 1940s, over 20 million acres of land in the United States was under irrigation. One result of improvements in groundwater pumping equipment was that large irrigated farms could take advantage of improvements in modernization and large scale agricultural practices.

Mid-19th century gravity dam design did not include consideration of water pressure acting upwards on the base or within the structure of solid masonry or concrete dams. Technologies to relieve or reduce this upward press (usually termed "uplift") began to be implemented as early as the 1890s, but it was not until the failure of the Bayliss Paper Company's dam in Austin, Pennsylvania on September 30, 1911 that killed over 70 people that uplift engendered intense concern among American dam engineers. This paper will examine how the engineering community responded to uplift during the period following the Austin, PA disaster through the implementation of technologies such as foundation grouting, cut-off trenches, foundation drains, and drains within a structure, that were designed to obviate the destabilizing effect of uplift. It will also examine how engineers promoted buttress dam technology in the teens and 1920's, in part because widely spaced buttresses were not vulnerable to uplift pressures. By examining published books and technical articles as well as actual designs built in the period 1910–1930, it will be possible to document how engineers developed practical technologies to counteract the effects of uplift prior to the proliferation of dams during the New Deal era of the 1930s. Attention will be paid to the efforts of John R. Freeman (a president of the ASCE), Arthur Powell Davis (Chief Engineer and Director of the U.S. Reclamation Service), and others to both heighten professional awareness of safety issues associated with uplift and to develop designs that accommodated the destabilizing effect of uplift. This analysis of how engineers responded to uplift provides an important context for understanding the collapse of the St. Francis Dam in March 1928.

The hydraulic ability of the Roman engineers is well known, and is clearly shown in their design of aqueducts and open flow canals to deliver water to the main cities of the expanding empire. However, the hydraulic skills of ancient engineers were highly challenged when confronted with the problem of raising large volumes of water and no progress whatsoever was made in this field. Water pumping was a typical problem of the mining industry, where underground work was limited by the infiltration of water and aquifer systems. Consequently, the earliest application of heavy duty steam engines in the 18^th century was to drive mechanical pumps to drain water from coal mines in England, marking the beginning of the so-called Industrial Revolution. However, before this revolution came about, in fact almost two centuries earlier, it is possible to trace back and discover the history of other mechanical inventions in the field of pumping. These are illustrated and described in technical treatises of the period and they led to the development of numerous types of pumping systems, some of which survived through to the end of the 19^th century. The paper is aimed at giving a short outline of the development of pumping devices up to the early Renaissance, and highlighting the contribution of 16^th century engineering to the design of mechanical inventions, which then paved the way to the industrial revolution of the centuries to come.

Over the last 250 years American hydraulic engineering has taken many forms. Some techniques, practices, and inventions were adapted from abroad. Others reflected an innate creativity. These sources are explored by discussing artifacts from the collections of the National Museum of American History. The focus of the paper will be on less well known events and people who made that history.

Over the past 65 years, scientists at the USDA-ARS Hydraulic Engineering Research Unit (HERU) in Stillwater, Oklahoma have made great strides in the design and technological development of hydraulic structures and vegetated channels. From its inception, the laboratory has gained notoriety for its accomplishments in vegetated channel design and development of design criteria for many hydraulic structures including trash racks, low-drop grade-control structures, and riprap design for rock chutes and stilling basins. Thousands of these structures and over a half-million miles of grassed waterways based on design criteria developed by the research scientists at HERU have shaped the landscape of the world into what it is today. In addition, research at the laboratory has provided field engineers with new techniques in measuring flow and soil erodibility. Today, scientists at the laboratory remain dedicated in their research efforts of hydraulic structures, channels, and issues associated with the rehabilitation of aging watershed flood-control and multi-purpose reservoirs. The purpose of the research has been and still is to assist engineers in making sound engineering decisions in their designs.

The historical contribution of Colorado State University to hydraulics and fluid mechanics is reviewed in reference to those who pioneered the analysis of hydraulic and wind engineering. The article first covers the "early developments" with Elwood Meade, Charles Lory, Ralph Parshall and Emory Lane during the Colorado A&M period. The name change to Colorado State University initiated considerable expansion through fruitful collaboration with the U.S. Geological Survey and the U.S. Bureau of Reclamation. The "expansion years" featured the contributions of Maury Albertson, Hunter Rouse, Jack Cermak and Everett Richardson under the leadership of Lionel Baldwin, Daryl Simons and Ray Chamberlain. The more recent "mature period" saw broadening of the programs and expansion into environmental engineering. Some of the key scientific achievements are reviewed, and the interaction between faculty activities, academic programs and research facilities that led to rapid growth and development are retraced. The success and visibility of the hydraulics and fluid mechanics programs also hinged on several other factors including significant contributions at the international level through projects in Pakistan, Columbia, and Egypt.

The laboratory, known until recently as the St. Anthony Falls Hydraulic Laboratory, was designed and built under the direction of a dedicated individual, Lorenz G. Straub. Straub had been a Freeman Fellow and observed several laboratories in Germany during the year of his fellowship. He came to the University in 1930 and promptly set to work to establish his own laboratory. His vision came to fruition through a WPA grant to the University of Minnesota and construction started in 1936. Straub came to be known as the "River Doctor" for his many studies at SAFL on several aspects of river engineering. The Laboratory building lies on the Falls of St. Anthony in Minneapolis, Minnesota where there is a drop of about 15 meters. Up to 9 m³/s may be drawn through the building and distributed to the many flumes for experimental research. Laboratory personnel have pursued studies in many areas of river engineering, hydrology and experimental and theoretical fluid mechanics. The legacy left by Straub is more than just a laboratory building and the equipment it contains. His vision of a university laboratory as a leader in the advancement of pioneering methods in water resources engineering as well as being an educational tool lives on. SAFL continues to explore cutting edge research on environmental and geophysical fluid dynamics and apply its knowledge to a variety of water-related engineering problems. This is a brief account of SAFL's history, present and future written by five of its Directors dating back to 1963.