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Contents

Credits
Abstract
Introduction
Open channel flow
Design of channels
Manning, summary
References and sources
Additional references

 

 

 


Credits, sources etc. - see also references at end

This has so far been abstracted (and slightly modified) from : On the Shoulders of Giants-part II; by Francis E. Griggs Jr., Prof. of Civ. Engrg., Merrimack Coll., North Andover, MA 01845, and Dir. of Quality Assurance, Clough Harbor Associates, Albany, NY 12205.
published in the ASCE Journal of Professional Issues in Engineering Education and Practice, Vol. 122, No. 1, January, 1996. ASCE, ISSN 0733-9380/96/0001-0017-0025


Abstract

The education of our future water resources engineers is incomplete without an appreciation of the men and women who created the profession of civil engineering in the late eighteenth and nineteenth centuries. This module traces our understanding of open channel flow and the development of the Manning equation. It begins in the time of Aristotle and Archimedes and ends in the late nineteenth century with the publication of Manning's work and equation.


Introduction

When people asked Isaac Newton how he had accomplished so much, he answered, "If I have seen further it is by standing on the shoulders of giants." If Newton acknowledged his debt to those who preceded him, we - teachers, practitioners and students alike - should recognize our debt to those early civil engineers who paved the way for us.

Who are these giants and why is it important that students have knowledge of the history of our profession? The reasons are many, but the primary reason is that lessons, which are applicable today, can be learned by studying the people and projects that transformed engineering from an art to a science over the eighteenth and nineteenth centuries. Students, once exposed to the past, will have a far greater appreciation of the contributions made by these people and be able to place their profession in a better historical and professional context.

Note from Francis Briggs: I believe that professors, given the time and opportunity, would be interested in incorporating history segments into many of their engineering courses. The main obstacle is that many professors do not have time to read enough background material to feel comfortable with lecturing on historical matters. Having taken up the study of the history of civil engineering, I can appreciate the time it takes to become comfortable in this new, and yet old, area of study. I have been so impressed, however, with the past and the founders of my profession, that I am, like the Blues Brothers, "on a mission from God." That mission is to make it as easy as possible for any professor to include history in his or her courses. This module that can be used in the teaching of fluid mechanics. The module includes photographs of the engineers who made it all possible, as it is important for the students to see, and remember, the images of those upon whose shoulders they are standing.

The key sources for this paper were the two books by Hunter Rouse (1957, 1976) on the history of hydraulics. The references given at the end of the article, however, are the source of most of the information.

Open channel flow and Manning formula

Preliminary Investigations

The study of mechanics, including fluid mechanics, had its start, as did most scientific matters, with the Greeks, particularly Aristotle and Archimedes. Aristotle (384-322 B.C.) believed that the motion exhibited by all elements, including water, was related to their tendency to return to their natural level. He discussed the movement of bodies through air and water, noting that "the medium causes a difference because it impedes the moving thing. Most of all it is moving in the opposite direction, but in a secondary degree even if it is at rest. . . ." He was, therefore, thinking about what we would now call drag, if the body moved through a medium (air, water) or fluid resistance if the fluid flowed over a stationary stream bed. Archimedes (287-212 B.C.) was much more involved with fluid behavior, building the Archimedes' screw and formulating the fundamental rules of hydrostatics: "Any solid lighter than a fluid will, if placed in the fluid, be so far immersed that the weight of the solid will be equal to the weight of the water displaced. . . . A solid heavier than a fluid will, if placed in it, descend to the bottom of the fluid, and the solid will, when weighed in the fluid, be lighter than its true weight by the weight of the fluid displaced." Neither thinker appears to have considered the flow of water through a channel or aqueduct.

The Romans were perhaps the greatest aqueduct builders of all time, having built them throughout their empire. Many of these aqueducts still remain a millennium and a half later. Frontinus, one of the greatest aqueduct builders, was aware that water only flowed downhill and that the greater the slope, for a given size channel, the greater the amount of water that could be transmitted. He wrote, for instance, that "the several aqueducts reach the city at different elevations. Whence it comes that some deliver water on higher grounds while others cannot elevate themselves to the higher summits." There is no evidence that the Romans built their aqueducts at specific slopes to achieve specific amounts of flow. The size of the channel appears to have come more from structural necessity than hydraulic need. The slopes appear to be based primarily on topography. Clemens Herschel (1899),  translated Frontinus' works and was convinced that while the Romans may have had a qualitative sense of the linkage between slope, area of conduit, and discharge, it was very poorly defined and not, in his opinion, a factor in their design of the aqueducts. Frontinus was aware of channel resistance. "Let us not forget in this connection," he said, "that every stream of water whenever it comes from a higher point and flows into a delivery tank through a short length of pipe, not only comes up to its measure, but yields, moreover, a surplus; but whenever it comes from a low point, that is under a less head, and is conducted a tolerably long distance, it will actually shrink in measure by the resistance of its own conduit." In other words, long, flat aqueducts yield a lessened amount of flow or discharge.

Leonardo da Vinci (1452-1519) also studied the flow of water in open channels and developed a nine chapter treatise on the subject. While he made many errors, as seen from twentieth century knowledge, his observations on open channel flow were remarkably accurate:

The water of straight rivers is the swifter the farthest away it is from the walls, because of resistances. . . .

Water has a higher speed on the surface than at the bottom. This happens because water on the surface borders on air which is of little resistance, because [it is] lighter than water, and water at the bottom is touching the earth which is of higher resistance, because [it is] heavier than water and not moving. From this follows that the part which is more distant from the bottom has less resistance than that below.

In other words, Leonardo had correctly understood bed resistance and the impact it had on the velocity distribution over the depth of flow. He also had a grasp of what is now called the continuity of flow: "A river in each part of its length in an equal time gives passage to an equal quantity of water, whatever the width, depth, the slope, the roughness, the tortuosity. . . ."   

It is clear that he knew that the flow of the river was a function of the product of area and velocity, such that, as the area increased, the velocity would drop, and vice versa. This fundamental equation that 

 

is known as the continuity equation. Leonardo's work on fluid flow, however, like much of his work, was not generally known by his peers and only became available to us recently.

Mariotte - 1686

Edmé Mariotte (1620-1684) was the next major investigator to experiment with the flow of water in open channels and published his work in "A Treatise of Hydrostaticks, Wherein the Motion of Water and Other Fluids, Is Considered." His work (Mariotte 1978) was originally published in 1686, shortly after his death, by his friend De la Hire, himself one of the preeminent French scientists of the time. Open channel flow was covered in "Discourse III-Of the Equilibrium of Fluids by Their Impulse" and "Discourse IV-Of the Measure of Water Running in an Aqueduct, or in a River." 

In Discourse III he wrote that "you must consider, that the water of a river does not go equally fast at its surface, and in its other parts; for the water near the bottom is very much retarded by meeting with stones, weeds, and other inequalities." He had used wax floats and measured the time it took for the floats to move a certain distance down the river. He described his experiment as follows:

In Discourse IV he continued his wax float idea to determine the amount of flow in an aqueduct. 

We must place upon water a ball of wax, loaded within with something heavy, insomuch that but very little of the wax lies above the surface of the water, for fear of the wind; and after having measur'd a length of 15 or 20 feet in the aqueduct, we shall know by a half second pendulum in how much time the ball of wax, carried by the current of the water, will run that distance. Afterwards we must multiply the breadth of the aqueduct by the height of the water, and the product by the space which the wax shall have run thro'. The last product which is solid, will give all of the water which shall have passed during the time of observation thro' one section of the aqueduct. To make this observation with exactness, it is necessary that the bed of the aqueduct should have the same inclination as the superficies of the water that passes in it. And moreover we suppose, that the water runs equally fast, on the top, and on the sides.

The latter statement would imply that Mariotte thought that the velocity was the same throughout the cross section of flow. That he did not make this oversight can be seen in a passage that followed the one just quoted. 

Mariotte assumed an average velocity of flow of two-thirds of the surface velocity. He did not give a functional relationship between depth and velocity, but the example he used indicates that he did not view the relationship as linear.

By the end of the seventeenth century it was known that the discharge of an open channel was a function of the slope, the shape of the channel, and the roughness of the channel bed. The functional relationship, however, was not known. Thinkers like Mariotte could, however, determine the discharge of existing channels by use of crude, surface velocity measuring devices and the continuity equation.

Design of channels

With this study of the flow of water in open channels up to the seventeenth century we will now move into the study of how channels can be designed to pass a desired amount of flow. We will show who determined the relationship between the slope, roughness, and shape of a channel, and the velocity of flow. The study will trace the development of one of our most-used formulas, the Manning formula. This formula (often called the Chézy-Manning formula), has its origins in the 1770s when Antoine Chézy was assigned the task of increasing the water supply of Paris.

 Chézy - 1776

Chézy (1718-1798) graduated with honors from the Ecole des Ponts et Chaussées and worked closely with Perronet, the first director of the school. He was active in a wide range of civil engineering work, including the construction of bridges and streets in Paris. He and Perronet were given the task of determining how much flow could be brought from the Yvette River into the city. They wanted to be able to predict the flow of water based on analytical methods rather than on experience and full-size tests. Chézy built model channels on which he ran tests to determine the factors that influence flow in an open channel. He ran his tests on a wooden flume approximately 200 m in length, made up of a channel 1.3 m wide and 0.52 m deep. At about the same time that Chézy was conducting his experiments, Pierre Louis DuBuat was also conducting a series of tests that perhaps had a longer life and greater effect than those of Chézy, even though Chézy's name survives and DuBuat's is known only to historians of hydraulics.

Chézy began his study with the following comments:

After having designed a channel, and having well adjusted and regulated its slope, it is very interesting to know if this channel will be sufficient for the water which is to flow in it. For this, it is necessary to know the speed at which the water can flow in the channel, which one assumes to have a uniform slope. . . .

. . . Whatever that initial velocity may be, it diminishes or augments rapidly enough to reduce to a uniform and constant velocity which is due to the slope of the channel and to gravity, of which, the effect is restrained by the resistance of friction against the channel boundaries. . . .

The velocity due to gravity, which acts continuously . . . is only uniform when it no longer accelerates, and gravity does not cease to accelerate except when its action upon water is equal to the resistance occasioned by the boundary of the channel; but the resistance is as the square of the velocity because of the number and force of the particles colliding in a given time; it is also as the part of the perimeter of the section of the flow which touches the boundaries of the channel. . . .

Upon calling the velocity , and that part of the perimeter , the resistance of friction will therefore be as . On the other hand, the effect of gravity is as the area of the section of the current, and as the slope of the channel or as the height which it descends for each toise [1.949 meters] length. Calling, therefore, the area of the section A, and the slope of the channel H, the effect of gravity will be as AH. 

Chézy then concluded that the ratio of the driving force and the resisting force of two streams (one with uppercase values and one with lowercase values) would be thus:

 

Where, in his analysis, the uppercase values were from a known stream and the lowercase values from a channel he was designing. Since the ratios are equal to each other they must be equal to a constant. Chézy later equated the left ratio to a constant and expressed his equation in the form in which it is usually seen.

where R = a/p is the hydraulic radius, and S = h. 

He knew that C was not a universal constant but one that would have to be determined on a case-by-case basis. However, based on his experiments he determined that C ranged between 31 and 44 when using metric units. The Chézy formula was usually expressed as:

or in current terminology

It is clear that the average velocity of flow varied with the square root of the hydraulic radius and the square root of the slope of the channel.

 Storrow - 1835

 Charles Storrow (1809-1904), an American civil engineer, born and educated in Montreal, studied in France at the Ecole Des Ponts et Chaussées in the early 1830s. He was exposed to the work of the French physicists, mathematicians, and engineers who were trying to combine theory and experiment into a comprehensive approach to the determination of the laws governing the flow of water in open channels. He came back to the United States in 1832 to work on the railroad connecting Lowell, Mass. and Boston. In 1835 he received a serious injury, which required a period of recuperation. It was during this period that he wrote his famous A Treatise on Water Works for Conveying and Distributing Supplies of Water (Storrow 1835). In his chapter on the motion of water in open channels he discussed only the work of de Prony, Eytelwein, and Bélanger. In his introduction, however, he reported on the works of Couplet, Chézy, Mariotte, Bossut, DuBuat, Girard, de Prony, Bélanger, and Eytelwein, thus making known to the engineers of America the best that the continent had to offer in the area of flow of water in open channels. This book became the bible of American engineers working in the area of hydraulics. In his book he converted the de Prony and Eytelwein constants into equivalent English units and put his calculations into a tabular format, which made the work even more important to American engineers. Thus, while Storrow contributed nothing new to the study of flow in open channels, he did make known to American engineers what had been developed in Europe.

Weisbach - 1845

In 1845, Julius Weisbach (1806-1871) wrote a book which, for the first time, made the teaching of fluid mechanics an integral part of engineering mechanics. He believed in the importance of a non-dimensional coefficient in his open channel flow equation. His equation was that 

 

or

where R = A/D

where was a coefficient that varied with V alone. Weisbach is also credited with being the first man to write an accurate equation for the flow through a weir.

 Saint Venant - 1851

 The great Saint Venant (1797-1886) in 1851 also made an approximation that 

in metric units. 

It was clear to these investigators, with the exception of Saint Venant, that based on theory and experimental data, the velocity was approximately a function of the square root of the product of R and S, times a constant.

 Manning - 1851

 Starting in 1851, Robert Manning combined the results of many experimenters into a single equation that best matched observed velocities of flow in open channels. Manning was an engineer in the Irish Office of Public Works during the years of the great famine. In 1848, as a new district engineer, he read the second edition of Traité d'Hydraulique by d'Aubisson des Voissons and from that time on had a great interest in hydraulics. His first paper was given in 1851 to the Institution of Civil Engineers of Ireland and dealt with hydraulics and hydrology. A later paper on the design of the water system of Belfast, Ireland, won the Telford Medal from the Institution of Civil Engineers, London in 1866.

D'Aubisson's equation was 

 

in English units and was sometimes published as 

 

Basing his calculations on a form of the de Prony-Eytelwein formula, Manning simplified d'Aubisson's equation (for computational purposes) to

where D = slope of the channel in ft/mile and R is in feet. 

He found that this simplified result did not always match the observed data very well. It was, however, of the same form as Chézy's formula of 1776.

Darcy and Bazin - 1857 and 1865

Henri P. G. Darcy (1803-1858) and Henri E. Bazin (1829-1917) performed a comprehensive set of experiments on pipe flow in 1857, 1858, and 1859. Darcy, a native of Dijon, France, was the designer and builder of the water system for his hometown. This system later became a model for several municipal water systems. In 1857, Darcy, working primarily with pipe flow, suggested that

 

 where D = pipe diameter.

Darcy died before the end of his studies, but his assistant Bazin carried on the experiments to their conclusion. In 1865 Bazin proposed an equation similar to Darcy's but this time for open channel flow.

where R the hydraulic radius replaced D the pipe diameter.

Bazin wrote that the "two coefficients are not, it is true, completely independent of the slope; but they vary within limits far narrower than those of the Prony binomial formula." He did not have a specific S term in his coefficient of the V2 term as his "two coefficients vary in an inverse sense as one modifies the slope of the canal. . . . . There is thus established a sort of compensation by which the formulas obtained for several slopes, although different from the first, give within ordinary limits of application almost identical values, and they can hence be replaced without inconvenience by a single formula with mean coefficients."

Gauckler - 1868

 In 1868, Philipe Gaspard Gauckler (1826-1905), after reviewing the data of Humphreys and Abbot and others, found that a single equation could not model the flow in streams of significantly differing slopes. He therefore developed two equations, one for slopes of less than 0.0007 and one for slopes greater than 0.0007. They were that

for slopes < 0.0007 and

  for slopes > 0.0007 

The latter equation has, as we will see, been credited to Manning but was in actual fact determined, in part, by Gauckler 30 years previously. Gauckler's C2 was not the same as Manning's, so even though the power on R was the same, the velocities would be different.

 Ganguillet and Kutter - 1869

 In 1869, the first attempt to link an equation to the roughness of the channel came from Emile Oscar Ganguillet (1818-1894) and Wilhelm Ruldoph Kutter (1818-1888), two Swiss engineers. Ganguillet was the chief engineer of the Bern Department of Public Works, and Kutter a member of his staff. Their study was prompted by the Mississippi River report by Humphreys and Abbot. Applying the American equation to the steep mountain streams of Switzerland they found that it did not predict the velocities or discharges of streams of this topography. They concluded that the American equation was only good for gentle slopes, and they developed a complex equation that for the first time included a bed-roughness term. It was as follows:

Where n is the Kutter roughness factor that runs between 0.01 and 0.035 for the usual channel surfaces. For the usual ranges of S, n, and R, the value of Kutter's C, to be used with Chézy's formula, ranged from 22 to 220. For values of S > 0.0005, the term m/S was frequently neglected, thus simplifying the equation somewhat.

Fteley and Stearns - 1883

 In the late 1870s Alphonse Fteley (1837-1903) and Frederic Stearns (1851-1919) were engineers on the Boston water supply. They were assigned to design and build the Sudbury Aqueduct in Massachusetts. As a part of that design they ran many tests on various conduits and described them in a Norman Award-winning article in the Transactions ASCE in 1883. Both were later to become presidents of ASCE. Their equation was 

 

It can be seen that they arrived at a power of R somewhat higher than earlier investigators but less than that at which Manning was to arrive.

 Manning - 1889

 In 1889 at the age of 72, almost a professional lifetime later, Manning (1816-1897)revisited the topic. 

Manning went back and restudied the previous data to determine whether or not a new formula, based on experiment, could be determined. He made his findings known in a classic paper to the Institution of Civil Engineers, Ireland in 1889, with a supplement issued in 1895 (Manning 1889, 1895). In his 1889 paper he reviewed the equations of DuBuat, Eytelwein, Weisbach, Saint Venant, Neville, Darcy and Bazin, and Ganguillet and Kutter. He then computed the velocities given by each formula for a given slope and for various values of R. He chose to use the mean of the velocities given by all the formulas as an approximation of the truth. He then curve-fit a line to data formed by plotting R and V for each formula. He found several equations that would fit the data, but he started with the following one:

  in metric units

This equation, he admitted, "was purely empirical," and he tried another approach, which yielded 

 

in metric units. 

He arrived at this formula by holding the power of his slope term at 1/2 and determining, using the same approach, the best power of R and the constant C. He knew that other formulas would also approximate the data, but he liked the form of the equation as it was similar to other, previously given formulas. Yet the 4/7 power on R concerned him, so he went back to Bazin's data and determined which power of R might fit the data better. Using a large number of Bazin's tests he found that values for the power of R ran between 0.6351 and 0.6778 for one battery of tests and 0.6176 and 0.6733 for another battery. Another set of tests, however, had a value range between 0.7635 and 0.8395.

 He concluded, even given the spread of data, that the formula was "sufficiently accurate to take the value of the exponent at 0.666 or 2/3. . . ." He then compared his formula in the form

 

to 170 experiments that had been conducted by Bazin, Kutter, Revy, Fteley and Stearns, and Humphreys and Abbot. Based on this analysis he concluded that "[if] these observations be correct, then the author's formula gives better results than either Bazin or Kutter."

 He knew this equation did not fit all of the data available, especially the Mississippi River tests by Humphreys and Abbot. He spent a great deal of time discussing the Humphreys data and came to the following conclusions:

 He therefore rejected Humphreys and Abbot's data as inaccurate due to the sensitivity of measuring the very flat slopes of the Mississippi, and with this data removed from the mix he found that his formula was within 7% of the observed velocities in all but 17 of the remaining 160 tests. He had, of course, determined values of C for various channel bottoms as a part of his analysis.

By the end of 1889, Manning had published the results of his work, which effectively modified Chézy's equation by having the power of the hydraulic radius at 2/3 instead of the  1/2 used by Chézy and some others. He did not like his own equation for two reasons. The first was that it was difficult in those days to determine the cube root of a number and then square it to arrive at a number to the 2/3 power. (If he didn't like the 2/3 power, one wonders what he thought of his earlier 4/7 power.) In addition, the equation was dimensionally incorrect, and so to obtain dimensional correctness he developed the following equation:

 

where m = "height of a column of mercury which balances the atmosphere," and C was a dimensionless number "which varies with the nature of the surface."I

In a supplement to his famous paper (Manning 1895), he wrote about his simpler formula that "it is worthy of remark that the value of the reciprocal of C corresponds closely with that of n, as determined by Ganguillet and Kutter; both C and n being constant for the same channel."

 In some late nineteenth century textbooks the Manning formula was written as

 

in metric units. The equation in English units was first published by Bovey (1901) as

Note that the 1.486 is a unit conversion factor from the metric to the English system and is the cube root of 3.28, the number of feet in a meter. The equation was changed in this manner so that the value of n is independent of the system of units chosen. 

Values of Manning's n for the usual channel bottoms range from 0.012 to 0.035. He never mentioned Kutter's n, so the n in the equation was based on knowledge of similar streams and their flow characteristics.

Bazin - 1897

It was after the publication of the results of Ganguillet and Kutter that Bazin changed the form of his equation to

where B = a roughness factor. In the English system of units the equation became

where m ranged between 0.5 and 1.75

The Bazin and Kutter equations were the commonly accepted equations up until early in the twentieth century. The Bazin equation was used primarily in France and England, and the Kutter Equation was used in most of the rest of the world

Summary

For many years Manning's equation was given in both forms, but as time went by with the results being about the same, the more complex, dimensionally correct equation was dropped and the more familiar equation adopted as Manning's equation. For his dimensionally correct formula, Manning gave a range of values of C in three different systems of units: dimensionless, feet, and metric.

The simpler formula slowly became accepted by engineers around the world and was incorporated into English language textbooks as early as 1899. In the United States, Horace King's Handbook of Hydraulics, published in 1918 (Second Edition 1929), firmly set the Manning formula as the accepted equation to use in calculating the velocity of flow in an open channel. His reasons for doing so were as follows:

Second edition comment: In the first edition of this volume the author advocated the adoption of the Manning formula for open channels. After eleven years, many engineers have recognized the advantages of this simple formula and its use has become quite extensive. In the present edition its adoption as a general formula applicable to both open channels and pipes is recommended.

With this recommendation the Manning equation, not the one that Manning liked, but the simplified equation, became the standard used in the United States. Over the 120 years between Chézy and Manning, the only thing that changed was the power on R from 1/2 to 2/3, and the modification of Chézy's C into a constant using Kutter's n. Some of the best engineers, mathematicians, and physicists of France, England, Ireland, Germany, and the United States had, however, a hand in shaping this apparently small change in the equation.

Today theoreticians favor a logarithmic-type formula as it is more in keeping with what we now know of the nature of the boundary layer between the bed of a channel and the moving fluid. Yet even though we know much more about turbulent flow than we did in the latter part of the nineteenth century, Manning's formula is still used by practicing engineers.

As we move into the study of open channel flow we should remember the work of da Vinci, Mariotte, Chézy, DuBuat, Eytelwein, Darcy, Bazin, de Prony, Girard, Humphreys, Kutter, Manning, and many others who developed, over a long period of time, the formula fundamental to our understanding of open channel flow.

REFERENCES

Babbit, H., and Doland, J. (1929). Water supply engineering. McGraw-Hill   Book Co., Inc., New York, N.Y.

Bovey, H. T. (1901). Treatise on Hydraulics. John Wiley & Sons, Inc., New York, N.Y.

Dooge, J. C. I. (1989). "The Manning formula in context." Channel Flow and Catchment Runoff-Proc., Int. Conf for Centennial of Manning's Formula and Kuichlings' Rational Formula. B. C. Yen, ed., Charlottesville, Va.

Griggs, F. E. Jr. (1994). "On the shoulders of giants." J. Profl. Issues in Engrg. Educ. and Pract., ASCE, 120(3), 254-264.

Herschel, C. (1899). Frontinus and the water supply of the city of Rome. Dana Estes and Co., Boston, Mass.

King, H. (1929). Handbook of hydraulics. McGraw-Hill, New York, N.Y.

Manning, R. (1889). "On the flow of water in open channels and pipes." Trans., Inst. of Civ. Engrs. of Ireland, Dublin, Ireland, 20, 161-166.

Manning, R. (1895). "On the flow of water in open channels and pipes-supplement to 1889 paper." Trans., Inst. of Civ. Engrs. of Ireland, Dublin, Ireland, 24, 179-207.

Mariotte, E.-A. (1978). "Treatise of hydrostaticks, wherein the motion of water and other fluids is considered." J. T. Desaguliers, translator, Reprinted by Arno Press, New York, N.Y.

Merriman, M. (1903). Treatise on Hydraulics. John Wiley & Sons, Inc., New York, N.Y.

Rennie, G. (1835). "On hydraulics as a branch of engineering." J. Franklin Inst., 15(Feb./Mar.).

Rouse, H., and Ince, S. (1957). History of hydraulics. Institute of Hydraulic Research, University of Iowa, Iowa City, Iowa.

Rouse, H. (1976). Hydraulics in the United States 1776-1976. Institute of Hydraulic Research, University of Iowa, Iowa City, Iowa.

Storrow, C. (1835). A treatise on water works for conveying and distributing supplies of water. Boston, Mass.


Additional references- still to be written.

American Public Works Assoc., 1976. History of public works in the United States. APWA, Chicago.

Pannell, J. P. M., 1964. An illustrated history of Civil Engineering. Thames and Hudson.

Reid, Donald. 1991. Paris sewers and sewermen. Harvard University Press.

Sprague de Camp, L. 1963. The ancient engineers. Ballantyne Books (printed 1984).