Arizona Agricultural Experiment Station. 178 



every farmer keeping such a record, as by this means only is one 

 able to determine the comparative value of the different cows in 

 the herd. 



Two dairymen were found who agreed to weigh and take 

 samples of the milk of each cow of their herds for a year, the 

 writer to furnish sample cans and blanks for bi-weekly reports, to 

 test the milk and keep the records. The work was started Nov. 

 ist and the year's record will be an illustration of what every in- 

 telligent dairyman should do for himself. 



Single tests covering periods of two weeks have been made 

 of other herds. 



THE USE OF HAND SEPARATORS. 



The writer has been called upon at different times to test the 

 efficiency of hand separators that the owners did or did not sus- 

 pect were doing poor work. 



In one case the operator was dissatisfied with his test at the 

 creamery but did not suspect his separator of being inefficient. 

 The skim milk was found to contain .4 of one per cent of butter 

 fat which indicated a loss of about $15 per month to its owner. 

 Upon examination the upper bearing was found to be loose and 

 in need of a new packing ring. Upon renewal of the packing 

 ring the machine worked well. 



Two other machines were tested and found to be inefficient 

 on account of poor construction. They have never given satis- 

 faction, are still a source of trouble and financial loss, and their 

 owners are unable to get any satisfaction from the manufacturers. 

 Other machines have been found to be doing good work. 



The above incidents indicate: first, that the centrifugal milk 

 separator, on account of the exactness of its construction should 

 be thoroughly understood by its operator; and second, that it does 

 not pay to purchase such machines of unreliable manufacturers 

 because they are cheap. The unsuspected loss in one case cited 

 shows the short-sightedness of using a poor machine at any cost. 



It is the intention of the writer to make a systematic test of 

 the hand separators in use in the valley for the sake of compari- 

 son with one another, with the gravity system of gathering 

 cream, and with creamery operations. 



