Dairying 



377 



192. Testing of milk for fat. It is important that the 

 dairyman know the percentage of fat contained in the milk, 

 for milk is often rated in value according to its fat-content. 

 To measure the fat, use is made of a centrifuge known as a 

 Babcock tester, which method was originated in 1890 by S. 

 M. Babcock, Chief Chemist of the Wisconsin Experiment 

 Station. The Babcock milk tester is used 

 also to determine the percentage of fat in 

 cream, skim-milk, buttermilk, and whey. 

 An outfit for making the test consists 



FIG. 151. Type of 

 Babcock test bottle 

 conforming to the 

 requirements of the 

 United States Bu- 

 reau of Standards, 

 and showing grad- 

 uations. 



\ 



/ \ 



9Gr 



FIG. 152. Types of cream bottles conforming 

 to the requirements of the United States Bureau 

 of Standards. 



essentially of a centrifuge, a pipette, an acid measure, whole- 

 milk bottles, cream-bottles, skim-milk bottles, cream scales, and 

 dividers. A centrifuge is a horizontal wheel fitted with swinging 

 cylindrical cups. A drawing of a small hand power four-bottle 

 tester is shown in Fig. 149, a. The wheel is rotated by means 

 of a gear that is turned in hand power machines by power ap- 

 plied at the handle. When the wheel is rotated the cups as- 



