682 EXPERIMENT STATION RECORD. 



cost of \yhieli would be ivtunuHl to the government by those settling upon the 

 tracts reclaimed. 



Official proceedings of the Fourteenth National Irrigation Congress, held 

 at Boise, Idaho, September 3-8, 1906 (I'roc. Xat. Iniij. Voitg., I'l {1906). pp. 

 280, pis. JfO). — A report of ihe proceedings of the congress held at Boise, Idaho, 

 Sept. 3-8. 190G, containing the various papers presented, the discussions upon 

 the same, and the resolutions passed. 



Closing the hreak of the Colorado River into the Salton Sink, southern 

 California, II. T. Cory (Engin. Neus. 56 (1906). \o. 26. pp. 671-67-'t, flgs. ,3).— 

 The author reviews the causes leading to the original break and describes the 

 several xmsuccessful attempts which have since been made to close the crevasse 

 in the river bank and thus prevent the inundation of a large body of irrigable 

 land in Imperial Valley. Unless the crevasse can be closed at once the course of 

 the river will be permanently altered, and a greater geographical change will 

 occur than has ever before been effected by human agency. 



Raising of water by compressed air at Preesall, Lancashire (Engin. Rec, 

 ■j-'f (1900). Xu. 9. pp. 243-245). — In this article, transcribed from a paper writ- 

 ten by James Kelly and published by the Institution of Civil Engineers, some 

 experiments are described in the operation of air lifts. The water-bearing 

 strata were found at a depth of 80 to 100 ft. below the surface. The com- 

 pressetl-air system was adopted, owing to the low yield from any one well and 

 the necessity, therefore, of raising water over a considerable area, together 

 with the desirability of having a system which would present a minimum pos- 

 sibility of Ijreakdowu — an important consideration in view of the appreciable 

 amount of sand in the water, which speedily ruined the valves and working 

 parts of a mechanical lift originally used. 



Several conclusions were deduced from the experiments, as follows : 



(1) That it was futile to attempt to force the output of a well, the best 

 efficiency being obtained at comparatively low rates of working. 



(2) The volume of free air used per cubic foot of water raised varied between 

 3 and 12 cu. ft., the lesser volumes being for the lower rates of working. 



(3) The efficiency based upon the ratio of work done in raising- water to the 

 indicated work of the air cylinders viiries between 20 and 40 per cent, being 

 dependent upon the ratio of depth of submersion of the air pipe to the height 

 of delivery (a ratio of 1.5 to 1 being the best), as well as upon the relative size 

 of air pipe and well tube, and upon the rate of working, the lower rates of 

 working giving the higher efficiency. 



(4) The best results were attained by keeping the velocity of air and water 

 combined at about 12 ft. per second at the point of entrance to the delivery pipe. 



(5) The size of the delivery pipe should gradually increase in diameter from 

 the bottom of the well to the surface. 



Brief notes on absorption losses on canals, etc., [R. G. Kennedy] ([Proc] 

 Irrig. Conf.. ,s'/7»/«, 1904, I. pp. .57, 58). — The writer ])refers to express absorjj- 

 tion losses as so many cubic feet per second per million square feet of surface 

 area of water, since it is claimed that it is a needless requirement to take 

 wetted perimeters instead of surface because, while seepage varies as the 

 former, evaporation which is included in all such data varies as the latter and 

 the depth enters into the equation in an unknown degree. 



