MILK 229 



With one exception, all the separators fulfilled the claims of 

 their manufacturers as to capacity and efficiency of skimming. 



All the separators used did satisfactory work under a far wider 

 range of conditions than is recommended by the manufacturers. 



Considerable difference seemed to exist between the various 

 separators as to substantialness and durability. 



There is a wide difference in the ease with which the various 

 separators were operated. 



The cheaper and newer machines did as efficient work in these 

 trials as the older and more expensive ones. 



There is no difference in the quality of cream delivered by the 

 various machines. 



There is no difference in the churnability of cream from the 

 separators used in these tests. 



These trials would seem to indicate that the choice of a hand 

 separator should be influenced very largely by its first cost and its 

 apparent durability. (Pa. B. 38.) 



Some conditions that affect the skimming efficiency of the hand 

 separator are the following: 1, smooth running; 2, speed; 3, clean- 

 ing of separator; 4, condition of milk; 5, temperature of milk; 6, rate 

 of inflow; 7, richness of cream. 



Smooth Running. No separator can be expected to do efficient 

 work unless it runs smoothly. When the separator is in operation the 

 milk, flowing into the bowl, is divided into three layers, namely 

 cream, skim milk, and separator slime. If the bowl revolves smooth- 

 ly the cream and the skim milk, thus separated, find their respective 

 outlets. If the machine trembles and jars, a portion of the cream 

 and skim milk are again mixed by the vibration of the bowl, with 

 the result that a relatively large amount of fat goes into the skim 

 milk. 



Speed. Every machine has a certain speed at which it will do 

 its most efficient work. The number of turns which the crank should 

 make per minute is usually indicated on the crank. If the speed is 

 reduced below that indicated, the skimming will be less complete and 

 more fat is lost in the skim milk. It is not advisable to run the ma- 

 chine at a higher speed than that required, as there is danger of dam- 

 aging the separator or of the bowl jumping the castings, nor does 

 excessive speed increase the skimming efficiency of the separator. 



Cleaning of Separator. It seems strange that, in the minds of 

 some dairymen, the idea prevails that it is unnecessary to thoroughly 

 wash the separator more than once a day, or once in two or three 

 days. The same men would rebel at the suggestion of sitting down 

 at the table and eating their dinner off the unwashed breakfast 

 dishes, and yet the principle is precisely the same. An investigation 

 of this condition showed that out of 57 dairies where the milk is 

 separated mornings and evenings 35 washed their separators after 

 each separation and 22 washed them once a day or once in two days. 

 Even where the bowl is flushed with warm water after each separa- 

 tion there remain in it remnants of cream, milk and separator slime 

 which rapidly undergo decomposition. When the warm milk of the 



