KURAL ENGINEERING. 1087 



voirs is t:il<(Mi u|) in sonic detail, the I'linii. iiiatci-iaj, and methods of coiistnu'- 

 lidii iM'iii.uc considci-t'd. From iiis iiivesti>;ations tlic autiior concludes that while 

 ill the district in (luestion cattle and stock ralsiufj nuist remain the ciiief indus- 

 try, yet the system ef ciintinuous ranjjinjr nuist eventually he ahandoned and 

 the raufje sTi])i)lemeiite(l ity 1h(> farm, which will he irrigated hy the flood waters 

 (if small streams cdnsei'N-ed in resei'voirs. The annual outlay in farming; (iO 

 acres, inciudim; liie intei-esl on the resei-voir and irrigation plant and the cost 

 of cultivation of the land, is jilaced ;it .$47(1. while from the products grown upon 

 this area it should he possihle to maintain diiriiii; the winter 1,2(M) iiead of 

 siiee|i. which should hring in an annn.il retui-n of .f;'.»(i(», leaving a net profit of 

 ,'j;4;!(> from winter feeding. 



Evaporation losses in irrigation and water requirements of crops, S. For- 

 TIKK ( r. .s'. Dcpt. A(/r., Office IJ.rpl. Slas. liiil. 111. /iii. il',. ///v. ,.^ /ii/s. HI). — 'Phis 

 hulletin re])orts the resiUts of investigations wiiicli have heen carried on for 

 a numher of years hy this Ottice in cooperation with the State of California 

 to determine not only the evaporation losses in irrigation, hut also the remedies 

 which will lessen these losses. Experiments were conducted in water-jacketed 

 tanks under field conditions in the following localities: Tulare. I'omona, 

 I'.erkeley. ("liiio. .nnd Riverside. Evaporation losses were determined by weigli- 

 ing the tanks, various methods of a))plication of the water and various systems 

 of cultivation and mulching being studied. From these experiments it was 

 foinid that the conditions having gi'eatest influence on evaporation from soils 

 ;ire the (piantity of water in tlie top soil, the temperature of the soil and w^ater, 

 ;ind the wind movement. Tlie application of water at a depth of ?> in. or 

 more was fouTid to subject it to a much reduced soil temperature and thereby 

 lessened evaporation, while cultivation after irrigation has the same effect, 

 since loose earth is a poor conductor of heat. Reduction of the temperature 

 of the water was found to be equally productive of economy, a reduction of 

 7° in temperature, decreasing evaporation from a water surface by 0.1 in. per 

 day, which points t(» the ])ossihillties of saving by applying water at night 

 when the surface soil is cool, or by applying it at sufficient depths to keep 

 it from coming in contact with the hot surface la.ver of soil. 



The experiments which have a direct bearing on pi-esent irrigation practice 

 are those testing the effects of cultivation after irrigation and applying water 

 in furrows of different depths. The saving in a 6-day period liy cultivation in 

 one case was 0.25 per cent of water applied and in another experiment, where 

 less water was aiii)lied. the saving in a 3-day period was 2.38 per cent of the 

 water a])plied. Tlu' maximum saving shown by the furrow experiments was 

 '.».23 per cent of the amount applied, the experiments covering 10 days. 



Another iKjint forcibly brought out by the experiments is the large loss when 

 water is aiijilied in frequent light irrigations, which keep the water always 

 exposed to the conditions causing the largest evaporation. 



In the experiments on water requirements of croi)s. it was found that for 

 conditions similar to those ;it Tulare IS to 24 in. is the best amount of water 

 to use in the irrigation of wheat, while liaiiey was found to have about the 

 same water riMinirements. Horse lieans grown at l^>erkeley were found to give 

 crops increasing with the amount ai)i)lied up to the maximum used of 38 in. 



Arterial drainage in Ireland [ lUuiiHvcr \ London]. IDS (1907), No. 2671', p. 

 S9.'i). — .V commission ajijiointed in I'.MC. to in(|uire into matters bearing on the 

 arterial drainage of Ireland has recently issued its reixirl. which conijirlses 

 various points of general interest. 



After reviewing the several drainage a<ls which liave b(>en ])assed from time 

 to time and which liave largely hecoine inoperative, due to the unsettled 

 condition of land tenure and iuie(iual or impossible distribution of benefits. 



