48 BULLETIN 376, U. S. DEPAETMENT OF AGEICULTURE. 



accepting the mean time of four batches of color traveling from that gauge to the outlet 

 of this particular pipe in the tailrace at the power house. For esich of the tests for loss 

 of head for differing velocities, color was injected at gauge No. 1 and timed to the outlet 

 of the constant- velocity 9-foot pipe. To determine the time necessary for the color to 

 travel between gauges for any particular run the time it spent in the 9-foot pipe 

 was deducted from the total. For each run of water two batches of color were timed 

 immediately before and after the gauge readings, and the mean time obtained was 

 accepted. 



A NEW SET OF FORMULAS FOR THE FLOW OF WATER IN WOOD-STAVE 



PIPE. 



So far as the writer has been able to ascertain, there have been two 

 suggested modifications of existing formulas and three sets of formulas 

 which were intended solely for use in the design of wood-stave pipes. 



With the experiments before them, which have been underscored in 

 Plate VII, Williams and Hazen in 1903 suggested the coefficient 120 

 in their general formula ^ given on page 6. 



In 1915 Andrew Swickard,^ after writing, "It is quite apparent 

 that n [in Kutter's formula] is not a constant for wooden pipe but a 

 variable that varies directly with the size of the pipe," offered the 

 following formula representing this variation of n, 



''-3o|oO + "-°l°5 (15)- 



This formula ascribes all variation in n to the change in diameter of 

 the pipe, while the present paper shows quite clearly in column 10 of 

 Table 2 and in Plate VI that this variation is also a function of the 

 velocity. This latter fact has also been noted by Moritz and by 

 Williams. 



The first formula proposed for sole use in design of wood-stave pipe 

 (see p. 6) was offered by C. H. Tutton ^ in 1899. Although not given 

 wide publicity in this country and apparently not used to any extent 

 here, Parker regards it with much favor, stating * in regard to gen- 

 eral formulas for the flow of water in pipes that " the most useful 

 formula seems to be the one given by Tutton." 



In this work Parker unfortunately misquotes Tutton's data from 

 that journal, giving as Tutton's formula for flow in wood pipes, V = 

 140 Ro.59g0.58^ instead of V= 129 Ro-^V-^^ (See p. 6.) 



In October, 1910, T. A. Noble published his own formula,^ 



q=1.28l>''^W'^ (16) 



which may be compared with formulas 1 1 and 14, pages 6 and 7. This 

 formula was not given the publicity it deserved and does not appear 



1 Hydraulic Tables, Williams and Hazen, New York, 2d ed., 1909, p. 8. 



2 The Design of Wooden Stave Pipe, Engin. and Contracting, Vol. XLHI, No. 1, p. 10. 



3 Journal Assoc. Engin. Socs., 23 (1899), p. 151. 



< Tlie Control of Water, P. k M. Parker, New York, 1913, p. 427. 



s Wood Pipe, T. A. Noble, Pro. Pac. Northwest Soc. Engin., Vol. IX, No. 1, Oct., 1910. 



