THE FLOW OF WATER IN WOOD-STAVE PIPE. 81 



in all the waters tested, and the variation in specific gravity from that of distilled 

 water was found to be very slight. As it was not practicable to make an examination 

 of the interior of this pipe the nominal size was accepted as correct. It conveys water 

 for several miles down the very rugged canyon spoken of in the discussion of pipe No. 

 31. Both vertical and horizontal curves are numerous but not excessively sharp. 

 These tests excited much comment at the time for the reason that they were the first 

 to show that a value of about 0.010 for n in the Kutter formula would not apply to all 

 sizes of pipe under all velocities. When compared with all other tests on large pipe, 

 with the exception of Nos. 45 and 46, the capacity of this pipe is shown to be about 

 equal to the discharge computed by formula. Compared to the new formula the 

 capacity is from 5 to 8 per cent less than average. For further discussion of results on 

 this pipe see page 9. 



DISCUSSION OF "FLOW OF WATER IN WOOD-STAVE PIPE." i 



By Gardnee S. Williams, Consulting Engineer, Ann Arbor, J/ic^.;THERON A. Noble, 

 Consulting Engineer, North Yakima, Wash.; D. C. Henny, Consulting Engineer, 

 U. S. Reclamation Service, Portland, Oreg.; E. A. Moritz, Engineer, U. S. 

 Reclamation Service, Denver, Colo.; E. W. Schoder, Professor in Charge of 

 Hydraulic Laboratory, Cornell University; L. M. Hoskins, Professor in Charge of 

 Department of Applied Mathematics, Leland Stanford Junior University. 



Mr. Williams: It may be interesting in connection with the Moritz formula as 

 expressed by the author [formula 9, p. 6] 



0.38 yi-s 



H = 



Di 



to call attention to the fact that from the experiments of A. V. Saph and E. W. 

 Schoder, published in the Transactions of the American Society of Civil Engineers, 

 vol. 51, the writer derived from the form given at the bottom of page 308 a formula 

 for general use with all kinds of pipe, 



0.38 V^-*^ 



H= 



D1.25 



which, it will be seen, is almost identical with the author's form of the Moritz for- 

 mula and has been taught to the students of the University of Michigan since 1904. 



From the standpoint of exact experimentation slight errors may be expected in 

 the author's results from the method of determining diameters of his pipe. The 

 effect of swelling of the wood in the staves, where they are restrained by the hoops, 

 may very probably change the diameter after they have become saturated from 

 what it was when they were dry. 



There is also some question as to the uniformity of the diameters of the glass tubing 

 and the author's practice of reading but one tube of his gauge (as indicated on p. 22) 

 may very likely involve a small error in the head, as in the writer's experience upon 

 careful examination he has never yet been able to find two pieces of tubing that were 

 exactly of the same internal diameter. 



> Appreciating that the present knowledge of the flow of water in wood-staves pipe is due to careful ex 

 perimentation and subsequent discussion, carried over a period of 20 years, the original manuscript of the 

 preceding paper was submitted to the above-named men, each of whom has been closely in touch with the 

 development of this knowledge. They were asked for criticism and comment. Acknowledgment is now 

 made of the time and labor expended gratuitously by these authorities in preparing their comments which 

 comprise the discussion given here. Many ot the changes suggestec^ by them have been made and to avoid 

 confusion their papers have been therefore edited to conform to such changes. 



Throughout this discussion "the writer" will refer to the name heading that particular part of the 

 discussion and "the author" will refer to the author of the paper. 



42463°— Bull. 376—16 6 



