THE MILK CONTRACTOR 241 



A change in the rate of inflow of the milk changes the ratio of skim- 

 milk to cream for while a diminution in the inflow reduces both the milk 

 and cream, the latter is most affected so that decreasing the inflow reduces 

 the percentage of fat in cream. 



High acidity of the milk reduces the cream. 



The percentage of fat in the cream varies directly with the percentage 

 of fat in the whole milk. The size of the fat globules varies with the 

 breed of the cow and the larger the globules the more readily the milk 

 skims. It is because of the large proportion of small globules in milk at 

 the end of the lactation period that strippers' milk does not skim well. 



The separator should be properly cared for in order that the milk 

 which is run through it may be uninjured and that the separator may 

 last long. 



A great deal of harm has been done butter manufacturers and city 

 milk dealers by unscrupulous agents of separator companies represent- 

 ing to farmers that the particular machine they were touting was so 

 easy to clean that but little time need be spent in washing it; in many 

 instances it has been stated that the machine might be sufficiently cleaned 

 by merely running water through it at the end of the separating. Such 

 statements are grossly untrue and if the advice is followed must inevitably 

 result in the production of inferior milk and cream. Milk clings to the 

 bowl parts of the separator and only patient and thorough cleaning will 

 remove it. If the least bit of milk is left adherent it will serve as food 

 for bacterial growths that will contaminate the milk as it is run through 

 the separator. The separator should be flushed with cold water at the 

 end of the run; then it should be taken apart and the parts washed, first 

 in cold water then in hot water and washing powder and finally they 

 should be rinsed. Then they should be hung up in a light airy place to 

 dry until needed again. If the parts are -put together in the machine 

 they are likely to rust. Where there are facilities for doing so, the parts 

 should be sterilized before use. 



Separators must be kept in good order or they will wear out more 

 quickly than they should. The gearings should be flushed once a month 

 with a good grade of kerosene and then reoiled with lubricating oil. 



In purchasing a separator attention should be paid to the following 

 points : 



1. Capacity; the machine should be large enough. 



2. Cost; a cheap machine is a poor investment. 



3. Durability; standard machines are most likely to give good service. 



4. Ease of cleaning is highly important; the more simple the bowl device the better. 



5. Spindle; whether attached or detached. Most standard machines have detached 

 spindles which prevents them getting out of line. 



6. Oiling system; an important feature for the machine should be kept well-oiled 

 with the gears bathed in oil. 



7. Speed of the machine. 



8. Efficiency. 

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