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I wish to emphasize the fact, however, that the work of the hydraulic laboratory is primarily and essentially of a laboratory nature. The various services named above are, so far as hydraulic problems are concerned, essentially field services, and for this reason I believe that the work of the hydraulic laboratory could be most effectively carried out at the Bureau of Standards, working in close cooperation with the field services.

It should be pointed out that there is a fundamental difference in point of view of the engineer and scientist. The engineer is charged with the execution of material projects and the handling of men, the scientist's duty is to study and discover principles in science and its applications, which may be taken over by the engineer.

Under the proposed scheme of a hydraulic laboratory at the Bureau of Standards, the field services would bring their problems to the laboratory which would then, from several possible alternatives, determine from their experiments what is the best solution scientifically, and the one which gives the most promise from the economic and financial point of view. The field services would then take the solutions of problems and apply them in the field. The two groups, scientists and engineers, are thus doing those things for which they are best qualified by training and experience. There is no interference, but on the contrary, the most effective kind of cooperation.

It is desirable that the national hydraulic laboratory should be under civilian control, staffed by professional men with civilian status and permanent tenure. General Jadwin in his report on flood control to the Secretary of War, December 1, 1927, states, paragraph 143:

"Measurements and observations on our large rivers supply the best hydraulic data on the flow of such streams, since actual experiments with full-sized structures is preferable to experience with small-sized models. However, on occasions questions relative to the flow of water can be worked out by small-scale experiments. Such experiments may be useful in some of our lock and dam design, etc."

Experience abroad has shown that on the contrary the quickest, most effective, and least expensive method of answering many river problems is to put the problem first into the laboratory. It may be expected that in general it will take several years and several million dollars for the river itself to answer a question, whereas in the laboratory an answer may often be obtained in a few weeks at a cost of a few thousand dollars. It is not proposed that this laboratory shall be a toy, but it will be a building 450 feet long, containing facilities based on European experience, adequate to answer in a satisfactory manner many problems relating to water flow.

The advantages of establishing the hydraulic laboratory in the Bureau of Standards may be summarized as follows:

1. The bureau already possesses a large concrete flume, 400 feet long, which can be made an integral part of the hydraulic laboratory. This flume has already been extensively used for testing water current meters for the various field services mentioned above.

2. A suitable site for the laboratory is available at the Bureau of Standards, involving no additional expenditure for land.

3. Power facilities for driving the pumps and other equipment are adequate. 4. The water supply at the bureau is adequate because the steadiest working conditions are obtained by recirculating the water.

5. The facilities for developing the necessary instruments used in hydraulic measurements are excellent and the shop equipment for such work is adequate. 6. The hydraulic staff of the laboratory if located at the bureau would have the great advantage of close contact with men in other branches of science and engineering. The European experiences have demonstrated the advantage of a laboratory located in a scientific center.

7. The underlying principle of the proposed hydraulic laboratory is research, which is in entire accord with the organization and purposes of the Bureau of Standards.

8. Civilian direction and staffed by professional men with civilian status with permanent tenure.

9. In the Bureau of Standards the laboratory will be centrally located, accessible to the other departments, and will be a service laboratory for them.

10. The bureau has had a long and successful experience in cooperating with other Government establishments and the public.

I am inclosing herewith a memorandum in the form of questions and answers in which the need for a national hydraulic laboratory is more fully set forth. Yours faithfully,

HERBERT HOOVER.

THE NEED FOR A NATIONAL HYDRAULIC LABORATORY IN THE BUREAU OF

STANDARDS

WHAT IS A HYDRAULIC LABORATORY?

A hydraulic laboratory is a building especially arranged for investigating the physical laws which define the motion of water, and for studying, by means of models and other special equipment, engineering problems arising in connection with the measurement, control, and disposition of large quantities of water, and the utilization of water for irrigation and power purposes.

The fundamental conception underlying experimentation by means of models in a hydraulic laboratory in this: If the model demonstrates that the conditions existing in a harbor, for example, can be reproduced typically by the ebb and flow of tides in the model, then it is possible, by placing regulating works in the model, to show the changes that will be brought about in the harbor if these regulating works are built. The effectiveness of proposed regulating works can thus be determined in advance by means of model experiments at small expense, and the most efficient and economical design selected from a number of proposed plans.

WHAT FEDERAL FIELD SERVICES WOULD BE INTERESTED IN THE ESTABLISHMENT OF A NATIONAL HYDRAULIC LABORATORY?

The office of the Chief of Engineers, which includes the Mississippi River Valley Commission, the Board of Engineers for Rivers and Harbors, and the various district engineer offices; the United States Geological Survey; the United States Coast and Geodetic Survey; the United States Reclamation Service; the Federal Power Commission; and the United States Department of Agriculture. General Jadwin in his report on flood control of the Mississippi recommends the establishment of a hydraulic laboratory in the office of Chief of Engineers. Many other Federal field services are, however, actively concerned with hydraulic problems. Furthermore, many States and municipalities are confronted with special hydraulic problems relating to river control, municipal water supply, and sewage disposal. Finally, the civil and mechanical engineers of the country are in urgent need of a suitable laboratory for the study of water-power development projects and conservancy systems. All of these needs could be advantageously met by the establishment of a national hydraulic laboratory on an adequate scale. The research carried out in a hydraulic laboratory is essentially different in character from engineering field work. It is in fact laboratory work, and as such could be most advantageously carried out at the Bureau of Standards where the facilities of the laboratory and the services of a skilled staff would be available to all concerned.

WHAT HYDRAULIC LABORATORIES ARE THERE IN THE UNITED STATES?

The Engineering Foundation in 1922 published a descriptive directory of the hydraulic laboratories in the United States (Publication No. 5) in which these laboratories are described in some detail. Most of these laboratories are located at our colleges and universities and are designed primarily for collegiate instruction. There are a few commercial hydraulic laboratories; some of these, such as the Allis-Chalmers Manufacturing Co. and S. Morgan Smith Co., give their attention entirely to the development and testing of their own hydraulic machinery and take in no outside work; others, such as the Holyoke Waterpower Co., make outside tests of hydraulic turbines. A number of the university laboratories have contributed substantially to hydraulic research along lines for which they were equipped. In general, the university laboratories are of very modest dimensions and the equipment has been selected primarily for purposes of instruction. There is not among them at present a single laboratory equipped to carry on experiments in river or harbor hydraulics.

WHAT KIND OF EQUIPMENT WOULD THE HYDRAULIC LABORATORY HAVE?

In the first place, it should be empasized that the building itself must be adequate in size. In the hearings before the Senate subcommittee in 1922-23

the fact was emphasized that the work needs to be undertaken on a scale of magnitude and a scope of inquiry that are not practicable for the comparatively small hydraulic laboratories of the universities of the country. The proposed laboratory is about 450 feet long and 60 feet wide. These dimensions are necessary to provide room for the large equipment to be installed and to provide adequate floor space for the numerous special models of hydraulic structures that will be built for test purposes. A proposed plan of the laboratory equipment is shown in drawings in Report 1240 from the Senate Committee on Commerce (67th Cong., 4th sess.). The plan includes two large flumes, a river flume, and a hydraulic flume.

The river flume is a tilting tank 250 feet long 20 feet wide and 3 feet deep, hinged at one end, with provisions for a wing extension on one side. In the river flume a model to scale of some part of a river which it is desired to study could be built up. The general laws governing erosion and deposition of sediment could be studied, the effect of various kinds of bank protection could be investigated, the proper location of spur dikes could be determined, and the relative merits of various shapes for the ends of spur dikes and the inclination of the dikes to banks could be tried out.

Adjacent to the river flume there would be a hydraulic flume 240 feet long 15 feet wide and 15 to 25 feet deep, which would be used in tests of models of hydraulic engineering structures, such as weirs, dams, spillways, "fall increasers," various types of energy absorbers and hydraulic jumps, baffle piers, sluice gates, tunnel entrances, bridge piers, etc. Plate-glass panels, set in the walls in the hydraulic flume at intervals will provide special opportunity for studying the circulation.

Provision will be made for a large measuring tank for use in the accurate determination of the coefficients of discharge of the weirs and other special watermeasuring equipment used in the experiments on models. A large supply tank will also be provided and so arranged that any required head up to 40 feet may be maintained with precision. A group of circulating pumps of graduated sizes will provide a total flow when required of 600 cubic feet per second.

In addition to the above equipment, a large space will be available for the installation and study of special models of various engineering projects. These models will be of temporary construction and will be taken down when the study is completed and replaced by other models as the work progresses.

IN WHAT WAYS WOULD A NATIONAL HYDRAULIC LABORATORY BE USEFUL TO THE FEDERAL FIELD SERVICES ENGAGED IN HYDRAULIC WORK?

Hydraulic laboratory experiments would be of value to the following services: (a) The Office of the Chief of Engineers, in connection with the design of dams, locks, spillways, diversion works, bridge piers, and hydraulic-power installations and in the development of works to reduce the erosion of river banks, increase the scour of river beds and similar problems; in brief, in connection with all projects or changes in projects for engineering works designed to improve rivers and harbors.

(b) The Federal Power Commission, in connection with such laboratory research as may be required in its field investigations of water-power projects, and the effect of one water-power development upon another.

(c) The United States Geological Survey, in connection with the development, through laboratory research, of more accurate methods and instruments for the measurement of the flow of streams and the effect of turbulence and variable direction of flow on such measurements; the experimental determination of the laws governing the transportation of débris, such as stones, sand, silt, and clay, down river channels; the laws governing the carrying capacity of streams for the transporation of débris in relation to slope, depth. width, and curvature of the stream.

(d) The United States Bureau of Reclamation, in connection with the design of engineering structures used in the development of national irrigation projects, such as dams, spillways, and hydraulic-power installations; the determination of coefficients for measuring the flow of water in channels and canals, and the coefficients of discharge through head gates and for overflow dams; transition losses in canals where a change in size or shape occurs; intake and outlet losses for flumes and canals; and the form and method of construction of drops of various kinds, where water must be dropped to a lower level and provision made for dissipating the power thus developed.

(e) The United States Coast Survey, in connection with the interpretation of tidal action along our seacoasts, the formation and movement of bars in navigation channels, the measurement of the velocity of tidal currents, and the erosion resulting from wave action on our seacoasts.

(f) The Department of Agriculture, in connection with the determination of the discharge coefficients of draintile; the effect of size, shape, roughness, and slope on the carrying capacity of canals, ditches, and flumes used in distributing water for irrigation purposes; improved means for the measurement of water supplied to the individual farmer for irrigation purposes; the development of more economical methods of pumping water to higher levels for use in irrigation; methods of designing bridge piers for Fedreal highways to insure against undermining, and to provide the least resistance to the flow of water and the free movement of ice.

IS THE BUREAU OF STANDARDS NOW COOPERATING WITH THE FEDERAL FIELD SERVICES WITH REFERENCE TO HYDRAULICS?

The Bureau of Standards now calibrates all the water-current meters which are extensively used by the field services for measuring the velocity of river and tidal flow. Special equipment has been installed at the bureau for this work, the major feature of which is a flume or testing tank 400 feet long in which the meters are towed through still water at known speeds. Much work of this kind is done every year for the Mississippi River Commission, the various district engineer offices, the Reclamation Service, the Geological Survey, the Coast and Geodetic Survey, and the Department of Agriculture. The Bureau of Standards also tests cement and other structural materials employed by the Reclamation Service, Department of Agriculture, district engineers, Panama Canal Commission, and other services in building dams, spillways, bridge piers, and other hydraulic structures. It has also made many tests for the Federal field services regarding the strength of concrete, steel reinforcing rods, cables, hawsers, chain, and other engineering supplies, as well as special investigations, such as the effect of alkali on concrete.

HOW WILL RELATIONS WITH THE FIELD SERVICES BE SET UP?

The purpose of the hydraulic laboratory is to help the field services in the analysis and solution of their problems. This cooperative relationship can probably be most effectively established and maintained by the aid of an advisory committee on hydraulics, consisting of representatives of all the Federal services concerned with hydraulics, and, perhaps, including one or more prominent outside hydraulic engineers as well. This committee could determine which problems were of most pressing importance and the order in which they should be undertaken. Advisory committees of this character have been of decided assistance and value in other lines of work at the Bureau of Standards.

In the case of any particular project the field service would supply the laboratory with the necessary data concerning the topography at the site of the project, together with plans of the proposed installation. The staff of the laboratory would build a model to scale in accordance with these plans, study its performance, and determine the effect of any modifications that gave promise of improving the performance or of lessening the cost of construction of the full-scale structure. The engineer in charge of the project would have every opportunity to witness the model in operation and the effect of such modifications in the original design as might be made and would have a complete report upon the performance of the models. He would then be in a position to make the most effective use of this information in the design or development of the full-scale project. The laboratory work would be carried out by men experienced and stilled in the measurements of models of hydraulic projects. The application of the results of this study to the full-scale project would be the function of the hydraulic engineer in charge of the project. The work of the laboratory staff thus supplements the work of the engineer but their fields of activity stand clearly apart.

WHAT ARE THE VIEWS OF AMERICAN ENGINEERS REGARDING A NATIONAL HYDRAULIC LABORATORY?

The testimony of a number of prominent American engineers engaged in hydraulic development was given at the hearings held September 8, 1922, and January 10, 1923, pursuant to Senate Joint Resolution 209, to establish a national hydraulic laboratory. The following excerpts are made from their statements:

John R. Freeman, Providence, R. I.:

"To-day there does not exist on the American continent even one laboratory for the study of river-training problems.

"I have come here to speak in favor of such a laboratory mainly because of my observations of the terribly threatening conditions during a tour of inspection along the lower Mississippi a few months ago during the highest flood ever known and because of my profound belief that such a laboratory would be extremely helpful toward better, cheaper, and broader protection against flood disaster by giving to American engineers more precise scientific knowledge than they now possess upon the operation of water currents in eroding, transporting, and deposing sediments; in causing river banks to cave and thus breaking down levees, and in creating bars of sand and gravel which obstruct navigation.

"The chief objects of this proposed laboratory are the promotion of economy in certain large expenditures and greater safety to life and property. *

*

"Tests with models in the laboratory are proposed to be used hand in hand with observations in the field or river, 'on the full-sized specimen,' as a means of obtaining the underlying scientific fact or law of nature with greater precision. The river-training problems to my mind are just now the most important among the many for which this laboratory would be useful.

* * *

"And, entirely apart from these matters of flood protection and river training, there are many problems of great importance in municipal water supply, in conservation of water for power development, in the safe design of bridge abutments and piers, problems in design of canals and pipe conduits for irrigation, in tests for improving the shape of boats, in developing more accurate apparatus for measuring velocity of currents, in the more precise formulation of certain hydraulic theories, etc., in which such a laboratory could be extremely useful.

*

"Hydraulic laboratories as a means for the study of problems of river training are highly esteemed among the skilled engineers of Europe."

Morris Bien, Reclamation Service: "I know that it (a national hydraulic laboratory) would be of great advantage to the work, as it would assist us in making more economical use of water and, directly or indirectly, reduce the cost to the settlers who, by law, are required to repay it. So we are strongly for it." J. A. Ockerson, Mississippi River Commission:

"After 43 years of active work by a corps of scientific men in nature's own laboratory, the river itself, it is believed that the commission has accumulated a volume of data covering practically all of the varying phases of the physics of the Mississippi River which are necessary to a full understanding of the regulation and control of the river. There is no 'woeful lack' of data, as has been charged.

"It is believed to be wholly impracticable to obtain any further useful data regarding the Mississippi River problems by the use of laboratory models, and the reason for this belief is to be found in the following briefs of conditions to be met with.

66

When I speak of 'models' I speak of the whole scheme of hydraulic laboratory work.

* * *

"As far as the hydraulic laboratory experiments are concerned, I can not conceive of anything that it could do that would materially modify the plans that are now under way. * * *

"My statement is not an objection to a laboratory; it is simply a statement to the effect that we do not think it would help our problem materially."

Clemens Herschel, New York City: "My argument is, and long has been, that there are needed in the United States several endowed hydraulic laboratories in which experiments and observations may be made and taken continuously, and by trained observers making this their life work. * * *; and I am hoping that the United States Government will make a beginning in this direction, principally for the use and benefit of its Government departments. * * The conclusion that I wish the subcommittee to come to is that a United States hydraulic laboratory should be made one of the permanent institutions of the country.

* *

*

John C. Ralston, Spokane, Wash.: "It is peculiarly the province of government to develop through its trained agencies those scientific criteria which must be ascertained in some manner if its greater hydraulic problems are to be solved expeditiously and economically."

John L. Harrington, Kansas City, Mo.: "I feel that the more exact, more satisfactory, more scientific knowledge would enable us to design works with greater accuracy, with greater certainty, and with greater economy, and therefore

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