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PROGRESS REPORT ON

NATIONAL HYDRAULIC LABORATORY

PROVIDENCE, R. I., February 24, 1931. Hon. JOSEPH E. RANSDELL, Hon. FELIX HEBERT, United States Senators,

Senate Office Building, Washington, D. C. GENTLEMEN: I appreciate your interest and desire to learn of progress of the national hydraulic laboratory, for which a few months ago Congress appropriated $350,000.

Much progress has been made by the staff of the Bureau of Standards in preparing plans, which it was hoped would be ready to submit to contractors for bids early in March, but I regret to report that these plans, so far as developed up to a few days ago, will not give a laboratory that can fulfill the promises which I made in the various hearings before Congress from 1922 to 1929, about useful large-scale fundamental research for improving the economy and accuracy of measurements of water by weirs, orifices, etc., nor has adequate provision yet been made for fundamental research concerning the hydraulic laws governing the flow of water in channels of various shapes at various velocities and slopes.

The Bureau's plans now nearing completion will nevertheless provide a laboratory in which a vast amount of useful work can be done, covering perhaps nine-tenths of the problems likely to be presented, and will give a laboratory generally comparable in scope with the best existing laboratories in Europe and America, excepting one or two of the recent European laboratories, notably the new laboratory at Obernach, near Munich, to which it probably will be decidedly inferior in precision of measurement for large-scale work.

This Obernach laboratory was promoted by some of the foremost European engineers, largely for testing out scale effect and for testing the accuracy with which the so-called doctrine of similitude, as used in experiments with extremely small models will be confirmed by experiments on much larger models, or with the behavior of the actual hydraulic structure.

These European hydraulic laboratories have each cost very much less than the sum provided for building this American national laboratory, but each has had the great advantage of being designed by an engineer of large practical experience. They have been gradually developed step by step during the past 20 years. The vast majority of researches on flow of water by means of models and the doctrine of hydraulic similitudes are best tried out in their preliminary stages with discharge of water seldom exceeding 5 cubic feet of water per second. The laboratory proposed by the Bureau staff can handle up to 250 cubic feet per second or double that in any of the European laboratories, but apparently will fail in precision of measurement of large quantities, and in opportunity for fundamental research in general fields of great importance to the designers of large hydraulic works

By a skillful use of the congressional appropriation of $350,000, it was entirely possible to have had here in Washington a national hydraulic laboratory not equaled by any now in existence anywhere in the world, in its scope both for ordinary small-scale researches and for large-scale researches in which flows of water up to 500 cubic feet per second could be measured with a degree of accuracy heretofore unequaled (viz, with errors of measurement not exceeding about onetenth of 1 per cent), and many determinations made of hydraulic coefficients in formulas for measuring the flow of water so accurately that once made they would serve all practical needs for a hundred years to come.

Such large-scale experiments are highly important to American public service engineering, as a means of developing and testing improved forms of water-measurement weirs, for promoting better forms of baffle piers and other means of dissipating destructive energy of current at the foot of high over-fall dams and spillways, and as a means for devising better forms of sluiceways, more effective syphon spillways, and for developing standard economic methods of riprap for preventing the erosion of earthen river banks by swift currents.

Also, it was highly important, and was possible within this appropriation, to design this laboratory of such scale and scope as to permit much needed determinations of the effect of turbulence and of twisting currents upon measurements of the flow of water by weirs, current meters, Venturi meters, Pitot tubes, and other instruments, by means of experiments on such a large scale as to command the confidence of practical engineers to much greater degree than the small-scale determinations heretofore made.

But, as I have said above, this great opportunity has been sacrificed, apparently through lack of experience of the members of the Bureau staff to whom this problem of design was assigned, and who had no background of practical experience either in large engineering design, or in the special problems of design for controlling or measuring large volumes of water. The problem of designing this laboratory was intrusted to skillful physicists rather than to experienced and skillful engineers.

Substantially every one of the great hydraulic laboratories of Europe, which for 10 years past have been contributing so greatly to the advance of engineering knowledge, has been designed chiefly by an eminent engineer of mature age, who had a background of 5 or 10 years or more of engineering experience on large and important work, and so brought to his designing of the laboratory a highly valuable experience. Also it is worthy of note that the great contributions to the science and practice of hydraulics in America have been by engineers of large practical experience, like the late James B. Francis, Clemens Herschel, of Venturi Meter fame, and various other engineers, including those of the United States Reclamation Service, the hydrographic branch of the United States Geological Survey, and certain enterprising engineers of the United States Department of Agriculture, and other branches, and not by mathematical physicists.

Senator Ransdell will so well remember my many earnest conferences with him on these matters during the past eight years that he may wonder why I have been unable to successfully advise our friends of the Bureau toward making a better use of the appropriation. I must beg him to remember that the Director of the Bureau of Standards and his staff have the sole authority over the design, and that they naturally have pride of opinion in their own capacity and skill for meeting any conceivable requirement for scientific research. The laboratory will be more of a physicists' design than that of a design by engineers experienced in hydraulic construction.

In my more than a half century of engineering, largely on hydraulic problems of great magnitude, I have also happened to have an uncommonly large experience with problems of hydraulic experiment in various laboratories. For more than 20 years I have been deeply interested in hydraulic research, and have made three extended tours for study of the hydraulic laboratories of Europe and have personally visited most of the notable laboratories in America. The results of a part of these studies are set forth in the large volume which you possess, copies of which were given to a large number of your associates in Congress, entitled "Hydraulic Laboratory Practice.” Also I have helped 10 or more American engineers to study in these laboratories abroad through the endowment of traveling scholarships each giving sufficient stipend for a year of study and travel abroad. Last summer, at my own expense, I made another tour of the European hydraulic laboratories, mainly for the purpose of learning of the very latest developments, and for aiding in the design of this national hydraulic laboratory at the Bureau of Standards.

I have tried in every reasonable way, as was stated in my letter to Senator Ransdell of June 24, 1930, to make my information available to the Bureau staff, but, although I have been treated with great politeness, I have been unable to bring them to understand the practical needs of various highly important features of the design.

In my letter of June 24, 1930, to Senator Ransdell, Secretary Lamont, and Director Burgess (which was published as Senate Document No. 208) I tried to make plain some of these matters. I am pleased to state that the later drawings for the laboratory by the Bureau staff, by whom four successive studies have been made by them, show vast improvement compared with their first sketches, which I mentioned in the communication just cited, and over which I was so greatly disturbed. But these Bureau designs still fall far short of what might be possible in scope and precision under this appropriation of $350,000, and after repeated conferences I am now on the point of making no further effort toward improving the design of this laboratory.

To show how hard I have tried to aid in making this national laboratory the very best in the world, I may state that in the preparation of various sets of drawings that I have presented to the Bureau staff, I have personally expended in pay rolls to assistant engineers and draftsmen, nearly $6,000, exclusive of office overhead and exclusive of my own time and traveling expenses, which time would have been of much value to me if otherwise applied.

I attach hereto a set of drawings and estimates of cost showing my latest and final effort, in a design which I am confident could be built within the appropriation and fit this laboratory both for the ordinary small-scale work, and for the large-scale fundamental research that is highly important to engineers in the Government services of reclamation, flood control, and river and harbor engineering, and also to engineers engaged in large problems of water supply and water power development. The attached estimates of cost were made up with extreme care in conference with the chief estimator of The Turner Construction Co., which built two of the most recent large buildings at the Bureau of Standards, and include allowance in the unit cost for contractor's profit. The total, which is slightly less than the appropriation of $350,000 made by Congress, thus covers the price at which one of the foremost building contractors in the United States is ready to bid for the completed building. Mr. Turner states that probably the contracts could be now placed at a smaller total cost than this estimate, because of the present business depression and the desire of various large contractors to maintain their organizations together at sacrifice of ordinary rates of profit.

I attach also a copy of my letter dated February 20, 1931, transmitting these designs to Doctor Burgess, which may interest you and some of your associates in the Senate and House, who made this appropriation of $350,000 available.

Following the letter to Doctor Burgess is a comparison of my plans with the most recent Bureau plans, which comparison I presented to him along with these final designs.

If the laboratory fails in some important respects to produce the results promised in the various congressional hearings, I hope that the documents which I now present will nevertheless permit you to still think kindly of my own efforts and good intentions. It may be well to explain that some of the features which are of highest importance, like the large measuring basin, the large forebay, the pump seats, and the main flumes, have to be built into the very foundations of the original structure and can not be properly added later. The pumps for producing the largest rates of discharge can advantageously be added a year or more later after previous research upon small model pumps for the purpose of perfecting the final design and so making of these large pumps instruments of research, useful for future designs in large drainage works. Very truly yours,

John R. FREEMAN.

(Copy]

FEBRUARY 21, 1931. Dr. GEORGE K. BURGESS, Director Bureau of Standards,

Washington, D. C. DEAR DOCTOR BURGESS: I am extremely sorry to have been prevented by illness from attending the conference with you which I had intended to have on January 27. I had my Pullman space and transportation all engaged Monday, but ventured a visit to my doctor, who sent me to bed for two weeks of intensive rest cure. The reason I missed my conference with you in New York, at the American Society of Civil Engineers, on January 21, was that after listening to your paper and two or three others, I found myself "all in," and went back to my hotel and to bed, in order to recuperate for the evening ordeal, in which I was on the schedule for a conspicuous part.

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