886 EXPERIMENT STATION RECORD. 



Discharges varied in the inverse ratio as the coefficient of roughness, the 

 hydraulic radius and slope remaining constant. 



The vertical velocity curves for the timber flumes are flatter than those for 

 the earth sections and approach more nearly a vertical position. " In gen- 

 eral . . . the amount of distortion of the vertical curves from a vertical line 

 varies directly as the roughness of the bed." 



It is concluded as regards current meter measurements: (1) The multiple 

 point method gives the closest determination of the actual mean velocity and 

 should be used where accuracy is more essential than time, and where the con- 

 ditions of flow are constant. (2) The vertical integration method is applicable 

 where reasonable accuracy is desired in a comparatively short time. (3) The 

 0.2 and 0.8 method is more rapid than either of the previous ones, but should 

 not be used in very narrow or very shallow channels. (4) Actual experience 

 has shown that the assumption upon which the 0.6 method is based is not true 

 in all cases. " With either the 0.2 and 0.8 or the 0.6 method approximate results 

 will probably be obtained, the degree of accuracy varying with the cross- 

 sectional factor and the roughness of the material." 



A comparison of formulas for estimating- run-off, J. W. Cunningham 

 {Eugin. and Contract., 40 {1913), No, 25, pp. 600, 691, fig. l).—For the purpose 

 of comparison the author gives the algebraic statements of a number of formulas 

 for run-o'ff, with results platted from conditions existing in southern Wiscon- 

 sin. The extreme variation in results leads to the conclusion that the use of 

 formulas for run-off is dangerous, unless such formulas are well founded on a 

 thorough study of local data and conditions. 



Irrigation experiments at the experimental farm of the Royal Imperial 

 College of Agriculture at Gross Enzersdorf (Austria) (ZentU. Landw., 93 

 {1913), No. 9, pp. 101-112; al)S. in Inteniat. Inst. Agr. [Rome^, Mo. Bui. Agr. 

 Intel, and Plant Diseases, 4 {1913), No. 8, pp. 1191, 1192).— Three years' flood- 

 ing Irrigation experiments were conducted on 2.47 acres of a lO-acre field of 

 4-year-old alfalfa. The irrigation water was supplied by centrifugal pumps from 

 underground sources. The test plat was divided into 10 plats, 1 remaining un- 

 irrigated, 3 receiving about 148,000 cu. ft. of water, 3 others receiving 258,000 

 cu. ft. of water during the vegetative period, and the last 3 being irrigated only 

 in the autumn. All the plats were manured alike. 



On the unirrigated plat a close relation was found between temperature and 

 the time of harvest, and also between the rainfall and the amount of crop. 

 This plat yielded 3 crops with 28 cwt. of dry substance per acre. Only the 

 first crop was satisfactory, the others being poor and unreliable. Four crops 

 were obtained from the irrigated plats, the average results being as follows: 

 Plats Irrigated during the vegetative period with 148,000 cu. ft. of water pro- 

 duced 4 tons, those with 258,000 cu. ft. 3 tons, and those which were irrigated 

 only in the autumn 3^ tons of dry matter per acre. 



Irrigation experiments with brackish water, O. Bordiga {Abs. in Inter-nat. 

 Inst. Agr. [Rome'\, Mo. Bui. Agr. Intel, and Plant Diseases, 4 {1913), No. 8, 

 pp. 1192-119 Jf). — To determine the possibility of utilizing brackish water for 

 irrigation on a large scale a series of pot experiments was conducted using 

 water of different degrees of salinity. Detailed analyses of the soil show that 

 it was clayey and had good mechanical structure and chemical composition. 



In the experiments, cotton, chicory, maize, and tomatoes were planted in 

 zinc vessels, each containing from 180 to 185 lbs. of soil, and manured by the 

 addition of 12 gm. of bicalcic phosphate and the same amount of ammonium 

 eulphate. The cotton and chicory died, but the other two crops were each 

 watered with different solutions as follows: Pure water; water containing 

 0.7389 per cent of salts as chlorids and carbonates; and water containing I, I, 



