THE FLOW OF WATER IN WOOD-STAVE PIPE. 7 



from an extensive series of experiments on wood-stave pipe from 4 

 to 55| inches in diameter and were offered for use on wood-stave 

 pipe only either jointed or continuous.^ 



In the development of formulas 9, 10, and 11 Moritz used only his 

 own experiments on the pipes as indicated on Plate VII, rejecting 

 all prior tests by other experimenters. 



(g) A new set of formulas is offered by the writer, based on all 

 experiments on round stave pipe known to him from description in 

 engineering literature, and supplemented by an extensive set of 

 experiments in which he was aided by Ernest C. Fortier. The 

 method used in developing these formulas is explained on page 50. 

 Hereafter any one of this set of formulas wiU be referred to as the 

 new formula. Arranged in the same order as the Moritz formulas for 

 comparison : 



„ 7.68 V^-« 0.419 V^-^« 



V=1.62D°-«5Ho-555 (13) 



Q= 1.272 D 2-65 H«-^55 (j4) 



It is to be noted that the exponent of V in formulas 9 and 12 is 

 the same, as is also the exponent of H in formulas 10-11 and 13-14. 

 The difference in the formulas is caused by the wide divergence in 

 the intercept curves shown in figure 4 (p. 56). As indicated in these 

 curves, the difference becomes greater as the larger pipes are ap- 

 proached, for the reason that all weight for large pipes in the Moritz 

 formulas came from his tests on the 55J-inch Mabton pressure pipe 

 (Nos. 45 and 46), and the position of the points representing the 

 intercepts for this pipe, in figure 4, indicates that this pipe was 

 abnormally smooth. 



Referring to formula 8a, it will be seen that the exponent of D in 

 the new formula is almost identical with the exponent of D in the 

 converted WiUiams-Hazen formula and that it follows the sugges- 

 tion of Schoder:^ "If the attempt is made to lump aU pipes except 

 the very smooth ones and the small tuberculated ones, giving thereby 

 more weight to large rough pipes and ordinary lap-riveted pipes, 

 then m will be found to vary inversely about as D^-^^ to D^-^"." 



TREND OF ENGmEERING THOUGHT REGARDING THE CARRYING 

 CAPACITY OF WOOD-STAVE PIPES. 



The ideas of the engineering profession concerning the carrying 

 capacity of wood pipe, expressed as direct statements or as formulas, 

 have varied widely during the past 20 years. Wood-stave pipe 

 enters into direct competition with iron and steel pipe. The claim 



1 For details of these experiments see Trans. Amer. Soc. Civ. Ejigin., 74 (1911), p. 411. 



2 Friction Head Hydraulics and Pipe Flow Diagrams, Ernest W. Schoder, Cornell Civil Engineer, May, 

 1910. 



