FROM THE PRACTICAL VIEWPOINT 



Thus the milk can be more readily drained from 

 the apparatus when it is being emptied. 



One striking advantage of the tubular type of 

 apparatus is found in the fact that it may be very 

 thoroughly sterilized. Steam can be admitted into 

 all the parts where the milk will enter, and the 

 steam may be under pressure if so desired. 



It is important that a machine of this type be 

 so constructed that no milk will leak from one 

 section of tubing into another section, but that it 

 all follows the course which it is intended that it 

 shall follow. In the forms shown in Figs. 8 f 9 

 and 10, the doors at the ends which cover the ends 

 of the milk tubes are provided with gaskets to 

 prevent this leakage. 



It is well to note whether or not these gaskets 

 are tight. In one or two forms, the gaskets con- 

 sist of sheets of metal which are backed by felt 

 or rubber in such a way that the metal readily 

 conforms to the projections of the tubes, thus mak- 

 ing a closely fitting cover. The metal sheet can, 

 of course, be readily cleaned. 



Fourth Type. The tank, or so-called batch sys- 

 tem of heating milk, is quite largely employed. 

 Heating tanks for this purpose are now manu : 



65 



