IRRIGATION INVESTIGATIONS 



G. E. P. Smith. W. E. Codk. H. C. SciiwalEn 



The Iirigatiou Department has functioned, as in the past, with 

 a wide range of duties, inchiding research, investigation, and much 

 extension service Avork. The personnel has remained unchanged 



THE FUEL OIL SlITUATION 



Pump irrigation in Ariz(jna, which has become of great im- 

 portance, has been based in large measure on the availability of 

 California i)etroleum oils of excellent character and at low cost. 

 In February, 1920, the fuel oil situation became critical. The price 

 of gas oil, or tops, the oil most used for individual farmers' pumping 

 engines, advanced over a hvmdred percent at the refineries, and 

 furthermore the supply seemed to have vanished, since it was mosi 

 difficult to get any refinery to make contracts for the season's sup- 

 ply. While the price advanced, the (juality depreciated. Shipments 

 of gas oil to at least three pump irrigation districts, lligley, Casa 

 Grande, and Tucson, were tested l)y this Department on request 

 and found t^ be unsuitable for the ordinary type of farm engine. 

 The oil could be burned in the engines only with the greatest diffi- 

 culty and with rapid deterioration of the engines. Strenuous pro- 

 tests by the farmers, based on the reports of the tests, resulted in 

 temporary improvement in the quality of shipments, but at inter- 

 vals throughout the year unsuitable oil has been received in the 

 Arizona pumping districts. 



The Irrigation Department has been studying fuel oils for 

 ])umping engines for several years, and has accumulated much data 

 on this subject. On account of the critical importance of the 

 matter at this time, particularly in the case of pumping plants 

 where the vertical lift exceeds fifty feet, a bulletin has been pre- 

 pared and is in press. The subject of the bulletin is "The Supply, 

 the Price, and the Quality of Fuel Oils for Pump Irrigation." 



Fuel oils from the oil fields of north Texas have been tested 

 with a view to promoting the production by the Texas refineries 

 of an oil suitable for 4-cycle electric-ignition engines, and of 

 minimum possible cost. 



