FROM THE PRACTICAL VIEWPOINT 



morning, it being kept cold in the meantime by 

 the circulation of cold water through the coils. 

 This milk may be heated on the morning of pas- 

 teurization as early as necessary to get it ready 

 for shipment, no handling or transfer of the milk 

 being previously necessary. 



In case the tank is used as both a heater and a 

 cooler, there is of course a considerable strain 

 upon the joints of the apparatus due to the expan- 

 sion and contraction of the metal. Those forms of 

 apparatus are therefore the most desirable which 

 are the most strongly constructed, and are there- 

 fore least liable to break. A coil of pipe is 

 stronger than a screw disc. 



Fifth Type. Another procqss which has been 

 used to a limited extent for pasteurized milk is 

 known as bottle pasteurizing. By this method, the 

 bottles are filled with cold milk and are hermeti- 

 cally sealed. They are then either placed in a 

 tank, where they are submerged in water, or else 

 they are carried under showers of water. In either 

 case the temperature of the water increases as 

 the bottles are carried forward. When the de- 

 sired temperature is reached, the bottles are then 

 held for the desired time and are then brought 

 77 



