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This detention by illness, the longest that I have suffered in 50 years, upset my plans seriously, and, although I have been at the office for several days past, am not yet back to 100 per cent efficiency.
I now intend coming to Washington some time next week, for I still have hopes of making plain to you that the laboratory as proposed by Mr. Eaton can not possibly fulfill the promises made to Congress about fundamental research. The chief defect of the Bureau's design is the small size of its measuring basin, which will prevent making important research with fairly large discharges on a cubic-foot basis of direct measurement and with a precision close to one-tenth of 1 per cent.
Mr. Eaton has been relying largely on the Venturi meters, for basic measurements, but this will not command the confidence of those who know the possibility of error in Venturi measurements due to air bubbles, twisting of the current, and lack of precision in piezometer readings, particularly with relatively small quantities flowing.
An important defect in nearly all the European laboratories, except that at Obernach, including the costly new laboratory at Zurich, is this inability to positively measure large quantities with precision. Moreover, I hoped that our American laboratory might excel all now in existence in Europe and in America by its ability to make much needed fundamental research on weirs, dams, orifices, and channel flow, with large quantities and a precision of measurement never yet equalled
My designs are worked out with this feature in view and with the idea of fully meeting the promises made in the hearings before Congress.
I regret that somehow in examining my designs your attention became chiefly focused on the large discharge proposed of 500 cubic feet per second instead of on the far more important feature of precise measurement of large quantities in a measuring basin with the aid of a quick moving diverting gate, which I am sure is entirely feasible from having used one in smaller-scale research. The quickly moving chronograph gate and the big measuring basin are fundamental requirements which have to be built into the original structure and its foundations. The pump for very large quantities can preferably be added later, after we have had some researches with model pumps, similar to the two set-ups that I saw in Europe last summer, one at Munich and another at Toulouse.
You may wonder at my earnestness in all of this, but I have been working on these ideas for more than 25 years and believe that now or never is the chance for a national hydraulic laboratory which can do things beyond the research of the many college laboratories and most of those in Europe, but which also can do the ordinary run of researches, which occupy most of the time of existing laboratories, with facilities not now excelled anywhere on earth.
The most eminent laboratory directors, like De Thierry, Rehbock, and Thoma have repeatedly urged on my attention that for the best routine work the laboratory should have abundant open floor space on which temporary set-ups of apparatus designed to meet the special problem can be conveniently erected and removed after the research is completed. In addition to the big flume, the big measuring basin, for facilities for precise measurement of large discharge, I have provided for both the small scale and the large scale research.
While at home ill I gave much thought to these matters and immediately upon returning to my office started Mr. Chick, at revising the drawings, so as to incorporate several improvements which both increased the capacity and lessened the cost, and I am now sending to you blue prints of this my final design marked "Study No. 4."
Many of the component parts, skimmer weir, diverting gate, forebay and forebay gate, also the special reinforcement of concrete will have the same details as shown in my previous set of about 27 sheets of blue prints.
Costs: On the basis of the unit costs in the Turner estimate, and while providing the same quality of construction shown in my latest previous design, including superabundant steel reinforcement of the concrete against temperature stresses and other stresses, and for preserving alignment and preventing distortion and settlement cracks, Mr. Chick, after carefully and precisely computing quantities, estimates a cost of buildings and fixed equipment, including contractor's profit at $289,480. Substantially the same items were previously estimated at $306,303, showing a saving of about $16,823 by simplification of design as per photostat of detailed estimate inclosed.
We find also that everything needed in portable apparatus to put the laboratory into immediate operative condition for four or five researches of the ordinary type going on simultaneously can be provided for the further sum of $59,812. This brings the total cost slightly within the congressional appropriation of $350,000.
Limestone finish: The preceding figures coming very closely to $350,000 for my design do not include limestone finish. We judge after allowing for the extent of the basement walls which are covered by a banking up of earth to avoid temperature stresses and also to give support, that a suitable amount of limestone trim, including parapet, window sills, and water-table course at the bottom, should not add more than $5,000, after deducting $4,150, which we have allowed for special concrete coloring and including window sills, window caps, etc. This extra $5,000 will be covered by the contingencies provided for in the following paragraphs.
For contingencies: As a safeguard for contingencies there can be held in reserve the cost of the propeller pump of 250 or 300 cubic feet per second discharge capacity, amounting to $12,000, which pump can be advantageously deferred for a year, pending research on a small model of same.
Moreover, parts of portable equipment, self-contained apparatus. etc., can be added gradually as cause for research develops, amounting to a total of about $15,000, which can, as you once suggested to me, be paid for from the first six months' appropriation for maintenance and operation. This gives a margin for contingencies of about $27,000, although I believe these contingencies will probably not arise.
Foundations. I still maintain and I am no novice in difficult foundations--for example, the Panama locks at Gatun, the dam site of rock broken by intersecting fault zones at Holter, Mont.; the dam site on possibly yielding foundations at San Pablo, Calif., etc., and from all that I have yet been able to learn about the underground conditions at the laboratory site, and from conferences with Doctor Stratton about foundations for your existing buildings) I believe the laboratory can be made safer against settlement cracks and distortion by practically floating the whole mass of the heavily reinforced foundation walls upon the decomposed rock on the levels which I have shown, than can be done by carrying detached foundation piers down to the so-called solid rock, which is not at all solid.
I am so confident that the whole laboratory could be completed according to my designs herewith submitted, with pumps upward of 250 cubic feet per second capacity, with attachments planned for future large pumps giving a total discharge capacity of 500 or perhaps 600 cubic feet per second, that I would be entirely willing to personally deposit the sum of $50,000 with the National Research Council, or other appropriate place, from which could be taken any sum found necessary to cover the over run or any sum necessary for repairs due to settlement cracks which occur within the next two years. I should make this deposit with the utmost confidence that it would not be called on for a single dollar, either for overrun or for repairs. Should loss occur I would take it cheerfully. It would simply be deducted from further contribution which I have been long intending to make for the advancement of hydraulic science.
I regret that in my personal conferences I have failed to make clear the purposes of design, and regret exceedingly that so much attention was given to the figure of 500 cubic feet per second of pump capacity, because this matter of pump capacity is of no significance whatever in comparison with the necessity for a large measuring basin of substantialty the size that I have indicated, fitted with a quick swinging gate, so that the error of measurement may rarely, if ever, greatly exceed onetenth of 1 per cent.
American services of water supply, flood control, and power development greatly need some precise, large-scale researches relative to flood discharge over dams, also discharges through orifices, and the determination of coefficients for new forms of water-measuring weirs and for determining coefficients of discharge of existing dams used for gaging flood discharge. Researches are needed for gate designs giving the least loss of head, also in baffle piers attached to the downstream face of dams for dissipating energy and preventing erosion, as well as for the effect of disturbance and turbulence in causing errors in measurement of discharge. I have provided for all of these in my designs.
The precision of measurement of large quantities (up to even 500 cubic feet per second) is the very essence of my design, and of its purpose to permit new determinations of weir coefficients and new forms of weir that should have world-wide acceptance for a century to come, and immediately be of great practical value to hydraulic engineers engaged on large projects.
The opportunity for fundamental research of this scope and quality of research would immediately stamp this laboratory as without a superior or equal in the world, and in my judgment, such fundamental research is of far greater importance to the greater Federal services than the mere ability to duplicate the small-scale researches such as are within the capacity of many existing laboratories.
Attached hereto are photostats of detailed estimates of cost, referred to above.
Since the inclosed sheets of blue prints include no elevations, it may be well to make plain that the estimates attached hereto comprise
pediment, bridge, grading, and ornamental architectural accessories included in my previous estimates.
I inclose several sheets of comparisons of capacity, etc., which clearly demonstrate the superiority of the Freeman design, particularly considering that its cost will be no greater than that the Bureau design of February 4, 1931. Probably it will be much less. Very truly yours,
JOHN R. FREEMAN.
APPENDIX No. 1
Estimate of quantities and cost for constructing national hydraulic laboratory at
Bureau of Standards, Washington, D. Č. Estimate by A. C. Chick, based upon revised plans by John R. Freeman, as of February 14, 1931, and unit prices mostly submitted by Turner Construction Co., of Philadelphia, as of December 31, 1930. This estimate of quantities has been determined independently of that of December 31, 1930)
Estimated total cost
. 146 . 365 .600
73.00 1,820.00 8, 246.00 11, 520.00
365.00 1, 057.00 1, 784.00 6, 185.00
600 1. 000
General contractor 1. Concrete (liberal estimate; walls made exceptionally 176, 803 Cubic foot....
thick to prevent serious deflection and to aid in
load stresses on basis of 16,000 pounds per square
55, 387 Square foot... 4. Forms:
6, 434 (c) Floors on steel
56, 866 ..do. (d) Walls (double)
31, 564 ..do. (e) Walls (curved)
1, 659 do. Stairs..
365 Linear foot Sills and coping.
1, 763 do.. (h) Water table and belt
1, 784 ..do. Metal-(a) Interior walls of main and return flumes. 12, 370 Square foot.. . Integral waterproofing: None provided. Allowance
has been made for using a higher grade of concrete
integral waterproofing compounds.
limestone used on some of the other buildings at
selection of aggregate.
rustication). 8. Interior concrete finish (pointing walls and ceilings)... 126, 210 .do. 9. Interior finish of main and return flumes (pointed, 12, 370 ..do.
carborundum rubbed, and smoothly surfaced). 10. Brickwork: Facebuick
132 Thousand.. Common brick
.do.. Basement floor.
21 do. 11. Scaffold lumber.
50 Thousand feet. 12. Wood doors
Square foot.. 13. Roof plank (2-inch).
2, 200 do. 14. Bridge and walkway (main entrance, 2d floor)
380 do. 15. Leveling.
25,000 do. 16. Hardware 17. Contraction joints in concrete walls (copper)
Subtotal (general contractor).
Estimate of quantities and cost for constructing national hydraulic laboratory at
Bureau of Standards, Washington, D. C.-Continued
18. Clearing site.
ing vertical girders, anchor rods, steel plate lining
for water passages, etc.
6-inch. 42. Tile drain pipe:
12-inch to sewer in Tilden Street
from central heating plant). 47. Electric wiring (lighting and convenience outlets