138 BUTTER-MAKING. 



is an example of this latter class. These two methods of regu- 

 lating the thickness and amount of cream are the most common. 

 It cannot be done while the machine is in motion. By some 

 this is considered a drawback. 



Other separators have a device whereby the amount of 

 cream can be regulated while the machine is in motion. For 

 instance, on the improved Danish Weston, there is a screw 

 attached to the skim-milk discharge-tube, by turning which 

 the end or point of the tube can be made to be closer or farther 

 away from the center, thus regulating the relative- amount 

 of cream and skimmed milk, and the thickness of the cream. 



2. Rate of Inflow. The rate of inflow of milk to the sepa- 

 rator has a large influence on the relative amount of cream 

 and skimmed milk. The greater the inflow to the separator, 

 the more and thinner cream will be obtained, and with a dimin- 

 ished inflow the less and thicker cream is obtained. This is 

 due to the fact that at a given velocity of the machine the 

 skim-milk discharge remains practically constant. So, if 

 more milk is turned on, the only place where the discharge 

 can increase is through the cream outlet; and if the inlet is 

 diminished, the cream will diminish until a certain time, when 

 the amount of milk, which runs into the machine, equals the 

 amount discharged through the skim- milk outlet, and then 

 there will be little or no cream. This is aptly illustrated 

 by Wing: " If the milk is turned into the bowl at such a 

 rate that .8 escapes through the skim-milk outlet, we shall 

 have .8 skim-milk and .2 cream. If, now, we reduce the rate 

 of inflow by .1, we shall get just as much skimmed milk as 

 before, but only half as much cream ; or, if the inflow is increased 

 .1, we shall get the same amount of skimmed milk and one 

 and a half times as much cream." The completeness of sepa- 

 ration will be the same so long as the separator is run within 

 the range of its capacity. 



3. Speed, The speed of the separator influences the rela- 

 tive amount of the cream and skimmed milk only in so far 

 as an increase in the speed of the bowl increases the capacity 



