76 



THE BOOK OF BUTTER 



45- 



40- 



30- 



the manufacturer is careful not to state a rate of speed 

 that will give results just above the border line of poor 

 separation. If these instructions of the manufacturers 

 _ are followed carefully, the 



separation of milk will be 

 found to be thorough. The 

 fact remains, however, that 

 the rate of speed may drop 

 several hundred revolu- 

 tions of the bowl below the 

 number designated, and 

 still the skimmed-milk will 

 contain approximately the 

 same percentage of milk-fat 

 as when the bowl is re- 

 volving at the so-called 

 normal speed. In the case 

 of the hand separators, 

 this amounts to five or ten 

 revolutions of the crank 

 less than the number given 

 for normal speed. 

 50. Percentage of fat in 



FIG. 38. A diagram representing w h o le milk The nerrent- 



the percentage of fat in cream as wno . ie milK ; 



influenced by the percentage of fat age of fat in whole milk is 



in whole milk. The figures on the var j a kl p T n +},\~ rP c nPP t 



left of the diagram represent per- Vai LD1 . e> ln 



centage of fat in cream, and those the milk from individual 



Percentage 345 

 Separator 1 



345 



Separator 2 



fa 



COWS 



two or three per cent from 

 one milking to another, and yet the cow may appear 

 to be in a normal condition. The fat-content of the 

 milk of a herd is not so variable as that from a single 

 cow. Other things being equal, the larger the herd, the 



