270 



Nature-Study Agriculture 



The cream 

 separator 



Reasons 

 for using 

 separator 



not much is wasted. Many farmers 

 use small Babcock testers and thus 

 are able to tell how much butter fat 

 each cow produces. To determine 

 how much butter can be made from 

 a given amount of butter fat, it is 

 customary to add one sixth to the 

 weight of the butter fat, thus taking 

 into account the water and salt that 

 the butter will contain. 



In 1879 a cream separator, which 

 had been invented in Europe, was 

 introduced in this country. Since 

 then several different separators have 

 been put on the market and are now 

 widely used on farms as well as in 



FIG. 216. A Babcock- . 



tester bottle. The di- creameries. These machines all use 

 Shtr/thett^ the principle of centrifugal force. 

 of butter fat. This The milk, being a little heavier than 



height is laid off from . ,, ,, ,. 



"o" on the graduated cream, is thrown to the outer part of 

 scale The upper pointer tne whirling separator, while the 



will then rest on the 



mark that indicates in cream collects at the center. A tube 

 of butter' fat. PerCentagC leading from the center carries away 

 the cream, and another tube leading 

 from the outer part of the bowl lets the milk escape 

 (Fig. 217). 



The advantages in using a separator are so great that 

 many farmers milking only a few cows use small hand 

 machines. Scarcely any of the cream is lost when a 

 separator is used, while in skimming by hand a fourth 

 of it is sometimes left in the milk. Also, when a sepa- 



