Understood to be twice the distance between the center of the disc 

 and the point of union between neck of test bottle and bulb when it 

 is whirling. 



Diameter of disc. 



Inciies. 



lO 



12 



14 

 16 

 18 



20 



Revolutions a minute. 



1074 

 980 

 909 

 848 

 800 



759 



The test bottle should then be filled to the shoulder with hot 

 water and whirled again for fully two minutes and longer if the fat 

 does not separate clear and oily. After the final filling which should 

 bring the fat well up into the neck of the test bottle, it should be 

 whirled again for two minutes to perfect the column of fat. 



The percentage can be read more safely and 

 Reading accurately by using a pair of dividers to measure 

 Results. the column of fat, than by trusting to the unaided 

 eye. 



-d 



*In measutjngthe fat column in the neck 

 of a milk test bottle the reading should be 

 made from a to b not to c or to d. 



*In measuring the fat column in the neck 

 of a cream test bottle the reading should be 

 made from a to c not to b or to d. The size 

 of the meniscus is magnified in this cut. 



*Reproduced from Testing Milk and Its Products, published by Mendota Book Co., Mad- 

 ison, Wis. 



1 



