32 DAIRYING 



First the friction of small fat globules is greater than large ones, 

 as they have more surface for a given amount of fat. Second, 

 the condition of the fibrium in milk makes cream separation 

 easier directly after milking than after standing some hours, and 

 third, the depth of milk in the bowl or the greater the distance 

 the milk must travel before leaving the bowl, the more efficient 

 is the skimming. 



279. A comparison of the centrifugal and gravity methods 

 shows : 



1. That the centrifugal separator skims milk satisfactorily 

 at a greater range in temperature, say anywhere from 80 to 120 

 degrees F. 



2. There is less exposure of the milk to air, dirt and bacteria. 



3. There is greater certainty of skimming all the fat from 

 the milk, as the machine is not subject to all the influences which 

 man cannot regulate, such as the temperature and weather, lack 

 of ice, transportation, etc., which affect gravity skimming. 



4. The separator cleans some of the dirt and slime from 

 the milk during the skimming. 



5. A better quality of cream is obtained where milk is 

 skimmed immediately after milking and the cream is perfectly 

 sweet, although it may be soured to churn or kept sweet. 



6. The richness of the cream may be easily regulated. 



7. Skim milk is in the best possible condition to feed when 

 separated right after milking. 



8. The cream is nearly all skimmed from the milk, the 

 skimmed milk containing only a trace of fat when all the condi- 

 tions of skimming are the best. 



The Development and Classification of Cream Separators 



280. Competition among manufacturers and the widespread 

 use of cream separators has caused a great development in these 

 machines in recent years. The great number of separators now 



