UNIVERSITY OF VIRGINIA PUBLICATIONS 



BULLETIN OF THE PHILOSOPHICAL SOCIETY 



SCIENTIFIC SECTION 



Vol. I, No. 10, pp. 243-265 ■ June, 1912 



THE FLOW OF WATER IN ARTIFICIAL CHANNELS: 

 CLEAN PIPES.* 



BT 



WILLIAM H. ECHOLS. 



1. In a paper read before this Society in March, 1910, On the Flow of 

 Water in Pipes, Conduits and Open Channels and pubhshed in the Trans- 

 actions, Bulletin No. 6, June, 1910, the writer discussed the flow of water 

 and designed a formula for representing the velocity. The design of 

 this formula seems to have been based upon principles which appear in 

 the main features to be correct, but in the determination of the empirical 

 constants in the formula the writer made use of the actual experiments 

 on certain pipes up to 2 feet in diameter and for pipes greater than 2 feet 

 and up to 8 feet in diameter he made use of the hydraulic tables constructed 

 independently by the two distinguished engineers, Mr. J. T. Fanning and 

 Mr. Hamilton Smith, Jr., under the belief that these results represented 

 the best obtainable information. During the two years since the publi- 

 cation of the paper referred to above the writer has more or less continu- 

 ously studied this question and in the light of more data and closer obser- 

 vation a clearer insight into the principles which underlie the law of flow 

 has been attained and I beg now to present these results. In the first 

 place we observe that for pipes of 4 feet in diameter and larger sizes undue 

 weight has been given to the experiment by Stearns, 1885, on a new cast 

 iron pipe coated with asphalt and very smooth and straight, 4 feet in diame- 

 ter, for which he found m =. 0.33 for F = 4 feet. Fitzgerald found 

 for a similar pipe m = 0.42 and Gale at Loch Katrine Water Works for 

 a 4 foot asphalted cast iron pipe 3| miles long found m = 0.50. The 



* Read before the Scientific Section, April 15, 1912. 

 243 



