144 



Milk and Its Products. 



motion of the particles and the motion of the churn 

 must not be confounded. If the motion of the churn 

 is increased so that sufficient centrifugal force is gen- 

 erated to cause the particles of cream to partake of 



Fig. IG. Barrel power churn. 



the motion of the churn, then, though the particles 

 may pass through space at a greater rate of speed, 

 the motion of the particles upon each other will be 

 lessened. A maximum motion of the particles upon 

 each other is obtained when the sj^eed of the churn 

 stops just short of setting up centrifugal force in 



