FROM THE PRACTICAL VIEWPOINT 



results. It has this advantage; that the milk 

 comes in contact with no new metal or apparatus 

 between the completion of the heating process and 

 the time when the milk is cooled. One disadvan- 

 tage is that since it requires considerable time for 

 a large tank full of milk to be discharged, the last 

 milk leaving the tank is held for a period consid- 

 erably longer than that which first flows from it, 

 and this long holding tends to interfere with the 

 proper rising of the cream. 



Continuous Holders 



The continuous or flow type holders differ from 

 the absolute holders in that the milk, instead of 

 being quietly held in retainers for a definite length 

 of time until the required period for holding is 

 completed, is simply retarded in its flow. This 

 period of retardation is so extended that before the 

 milk passes to the cooler it has retained its tem- 

 perature for the length of time desired. 



There are several forms of continuous holders. 

 One of the first of these is the so-called Park 

 holder, invented by Dr. William H. Park, of the 

 New York City Department of Health, and pat- 

 Ill 



