1010] KURAL ENGINEERING. 883 



pliints tested ranged from $3.86 for a plant b;iviii<;- a lift of 44.5 ft. and a dis- 

 charge of 120 gal. per minute to $14.69 for a plant having a lift of 97 ft. and 

 a discharge of 116.5 gal. per minute. 



Other general information bearing on the subject is given. 



Surface water supply of Hawaii, July 1, 1917, to June 30, 1918 (U. S. 

 Geol. Snrvei/, Water-Suppli/ Paper 485 (1919), pp. 172). — This report, prepared 

 in cooperation with the Territory of Hawaii contains the results of measure- 

 ments of flow of certain streams and ditches and records of rainfall in the 

 Territory of Hawaii, made during the year ended June 30, 1918. 



Surface water supply of the lower Mississippi River Basin, 1917 (U. S. 

 Geol. Su7^-ei/, Water-Supply Paper 457 {1919), pp. 25+XXXn, pis. 2).— This 

 report presents the results of measurements of flow made on the Arkansas and 

 Red River Basins during the year ended September 30, 1917. An appendix 

 of gauging stations and publications relating to water resources is included. 



Departures in canal design and location effect saving, E. N. Bryan (Engin. 

 Xcicfi-Rcc, 82 {1919), No. 1, pp. 48-50). — The author describes methods em- 

 ployed on the Waterford Irrigation District in California for effecting economy 

 in canal design and construction, including minimum excavation, greater bot- 

 tom width, omission of upper levee and change of location, use of full tunnel 

 bore, provision of wasteways for cleansing pockets, location without use of 

 the transit, and use of mass diagrams. 



Why some irrigation canals and reservoirs leak, A. P. Davis {Engin. Neios- 

 Rec, 80 {1918), No. 14, pp. 663-665, fig. i ) .—Experience of the U. S. Reclama- 

 tion Service has shown that in numerous cases the admission of water into 

 irrigation canals and reservoirs has disclosed the existence of subterranean 

 cavities which cause settlements and cave-ins. Three notable examples of canal 

 troubles and six with reservoirs are described. It is concluded that canal 

 troubles may usually be remedied by puddling the cavities or by relocation. 



" Remedies in the case of reservoirs are not so easy. Puddling is useless 

 if the subterranean conditions are such that the seepage of water can get 

 away and thus let the seepage continue. No reservoir in earth is of much 

 value if it continuously seeps at the rate that water can pass vertically through 

 puddled earth. The problem then is to avoid regions where subterranean 

 conditions are such that the water can escape. A few rules of caution may 

 be of value: (1) Avoid reservoirs adjacent to gj-psum deposits and to lime- 

 stone deposits which show evidence of caves. (2) Examine critically reservoirs 

 in volcanic rock, as a few have failed in such locations. Coarse-grained sand- 

 stone seems to be an object of suspicion, and should be critically examined. 

 (3) Natural depressions are treacherous and should be examined with care, 

 and if they are near deep canons or underlain with coarse material where 

 water might readily escape no superficial tightness will avail to make them 

 effective." 



Algse growths increase value of n in Kutter's formula, P. Taylor (Engin. 

 News-Rec, 81 (1918), No. 4. pp. 179-181, flgs. 8).— Studies made by the U. S. 

 Reclamation Service during 1912 to 1916 in the Tieton Irrigation Canal lined 

 with i-einforced concrete blocks indicated that algje growths raised the factor 

 n in Kutter's foi-mula from 0.012 to 0.014. 



The theory of underdrainage, W. J. Schltck (loica Engin. E.vpt. Sta. Bui. 

 50 (1918), pp. 57, pi. 1, fliis. 8). — It is the purpose of this bulletin to present 

 those principles which determine the efficiency of the operation of a well 

 constructed imderdrainage system, with particular reference to drainage condi- 

 tions and requirements in the State of Iowa. " Only those phases of the whole 

 study of soils and soil moisture that are essentially a part of drainage en- 



