FuKL Oils for Pump Irrigation 413 



Most of the oils tested were what might be termed regular as to 

 color, odor, and other qualities. Occasionally a carload of freakish 

 oil is received, and usually such oils give much trouble. As- an ex- 

 ample, a sample of oil was received from Higley in June, 1919, which 

 had been shipped from the refinery as a "special fine oil". The oil had 

 a flash point of 71° F. and a specific gravity of 41° B., but it possessed 

 a strong odor suggestive of turpentine, and contained much flocculent 

 material which settled slowly after shaking, flaky particles sticking to 

 the sides of the bottle and more granular particles sinking to the bot- 

 tom. The rancher who submitted the sample stated that repeatedly 

 the feed-pump became clogged so tiiat the engine could not get any 

 oil, and a black deposit settled on the cylinder. He harl tried filtering, 

 but that "only held back the coarse stuft' and let the dissolved" matter 

 pass. The oil necessitated an undue amount of water with the charge, 

 but. strangely, the exhaust was not smoky. With such apparatus as was 

 available at the University at that time, a distillation test was run. 

 The oil began to boil at 167° F. but no distillate was caught until the 

 temperature reached 257° F., suggesting casing-head gas. At 347° F. 

 56 percent was distilled and at 446° F. 82 percent. Further heating 

 yielded only a few drops of thick oil. The residue, about 18 percent, 

 was almost black and contained solid particles. Upon mixing some 

 of this residue with acetone, most of the solids dissolved, indicating 

 asphalt. On examination twelve hours later, a thin coating resembling 

 vaseline was found on the bottom of the beaker. This was probably 

 paraffin. Upon mixing some of the residue with carbon bisulfid, 

 most of the solids dissolved, leaving a small amount that appeared to 

 be dirt. This oil may have been a product of cracking or it may have 

 been a light-gravity distillate that had decomposed in storage, to which 

 some improper heavy oil had been added so that it might be classified 

 as fuel oil in shipment. 



Another freakish oil, received in Pima County in September, 

 1920, tested 42.5° B. The flash point was very low, less than 59° F. 

 But on distillation it was found to have a wide boiling rauQ^e with a 

 high end point, and in use it was very troublesome, causing engines 

 to smoke badly. 



During: 1920 many oils have been tested for boiling range in the 

 standard Engler apparatus described above. These tests have been 

 made at atmospheric pressure of about 27.6 inches, which should 

 pause the samples to be somewhat more volatile than if tested at sea 



