52 Transactions. 



newly cleaned or new. The diameters vary from 3 - 333 ft. to 5-0938 ft. 

 by four different observers and six sets of observations. All the readings 

 are remarkably close, and form a most valuable groundwork for further 

 investigation. There are in all forty-six observations, all within the 

 limit of observational errors, which could be represented by a single 

 curve. All that is required in regard to this class of surface is a number 



of observations between the values of log. = 6 and log. _ = 7. Even 



V V 



as they stand a curve could be drawn with a fair amount of probability 

 as to its correctness, as the observations follow the curve for brass tube ; 

 but, as the determination of the function is essentially an experimental 

 one, the completion of the curve should be left to experiment. 



Wood-stave Pipe. 

 Among the available experiments on wood-stave pipe, the most 

 complete are those by Moritz." Two classes of pipe are used — viz., 

 jointed and continuous. The frequency of joints in the former case is, 

 however, not specified. The observations on I8in., 14 in., 12 in., 8 in. 

 jointed pipe, and on a 55fin. by Moritz, and a 31 in. continuous by 

 Moore, are plotted in fig. 2. It will be seen that in spite of the care 

 exercised the results obtained on some of the pipes are somewhat erratic, 

 due, no doubt, to the effect of impulses travelling through the water. 

 The results as a whole are not consistent, and they do not lie near enough 

 together to enable them to be represented to a single line, as the under- 

 lying principle demands. Nevertheless, they do not disprove the ap- 

 plicability of the principle, as the results are not consistent, whilst the 

 difference between the observations on the same pipe are greater than 

 the differences between the different pipes. 



Kiveted Steel Pipe. 

 Of the numerous experiments on riveted steel pipe, but two or three are 

 suitable for the purpose of this paper. As a rule, the range is short and 

 the readings erratic, whilst the particulars of the pipe are not complete. 

 One of the most complete and extensive sets of observations is that made 

 by Marx, Wing, and Hoskinsf upon a pipe 601 ft. in diameter, the 

 circular joints being butted, with a strap on the outside. The longitudinal 

 joints are also butted, with a strap both inside and out. The length of 

 pipe was 4,427 ft., with fourteen joints, and contained thirteen bends of 

 30 ft. radius and one of 40 ft. radius. The temperature of water is also 

 recorded. The results are plotted in fig. 3 and marked a. On the same 

 diagram are plotted experimental values by Herschellj on a 48 in. pipe 

 marked b and a 36 in. pipe marked c. In each case the plates are Jin. 

 thick and asphalted, built with alternate large and small cross-sections. 

 All three sets of results are erratic, giving widely different values of 1/c 2 



vd 

 for the same value of , and the readings on the same pipe differ more 



v 



than the difference between the pipes, so that no conclusion can be drawn 



as to the complete applicability of the principle involved. All that can be 



* E. A. Moritz, Experiments on the Flow of Water in Wood stave Pipes, Trans. 

 Am. Soc. Civ. HJng , vol. 74, pp. 411-51, 1911. 



t C. D. Marx, C. B. Wing, and L. M. Hoskins, Experiments on the Flow of 

 Water in the Six-foot Steel and Wood Pipe Line of the Pioneer Electric Power Com- 

 pany at Ogden, Utah, Second Series, Trans. Am. Soc. Civ. Eng., vol. 44, pp. 34-54, 1900. 



I One Hundred and Fifteen Experiments on the Carrying-capacity of Large Riveted 

 Metal Conduits, John Wiley and Sons, N.Y. 



