48 BI'LLETIX 376. U. S. DEPARTMENT OF AGRICULTURE. 
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 each of the tests for loss 
of head for differing velocities, color was injected at gauge Xo. 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 FOKMULAS 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 YII. Williams and Hazen in 1903 suggested the coefficient 120 
m their general formula x given on page 6. 
In 1915 Andrew Swickard, 2 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. 
"=™-°- 0105 < 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. IT. Tutton 3 in 1S99. Although not given 
wide publicity in this country and apparently not used to any extent 
here. Parker regards it with much favor, stating 4 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-^s -^ instead of V= 129 K°- 66 s°- 51 . (See p. 6.) 
In October. 1910. T. A. Xoble published his own formula. 5 
Q=1.2SD 258 H°- 5&5 (16) 
which may be compared with formulas 1 1 and 14. pages and 7. This 
formula was not given the publicity it deserved and does not appear 
1 Hydraulic Tables. Williams and Hazen, Xew York, 2d ed., 1909, p. S. 
- The Design of Wooden Stave Pipe, Engin. and Contracting, Vol. XLHI, No. 1, p. 10. 
5 Journal Assoc. Engin. Socs... 23 (1S99), p. 151. 
« The Control of Water, P. a M. Parker, Xew York, 1913, p. 427. 
« Wood Pipe, T. A. Xoble, Pro. Pac. Northwest Soc. Engin.. Vol. IX. Xo. 1. Oct.. 1910. 
