196 CANADIAN DAIRYING. 



with separators. All separators should be provided 

 with a speed indicator, which shows the rate of speed 

 at any time by a glance. Present speed indicators 

 are clumsy, inconvenient pieces of mechanism, and 

 manufacturers ought to remedy this defect at once, 

 because speed is such an important factor in good 

 work with a cream centrifuge. When speed or tem- 

 perature of the milk, or both, increase there may be 

 a slight increase in the feed. It is not wise, however, 

 to increase the speed beyond 500 revolutions per 

 minute over that recommended by the manufacturer. 



We may repeat the law of centrifugal force as 

 applied to centrifugals : double the diameter of the 

 bowl and the centrifugal force is doubled, double the 

 speed of the bowl and centrifugal force is increased 

 four times. 



The separator requires constant oil of the best 

 quality, especially when creaming pasteurized milk. 

 The manufacturer's direction should also be closely 

 followed. A separator must run smoothly to do good 

 work. Trembling or vibration causes an added loss 

 of fat in the skim-milk. The cream should be 

 delivered in a smooth condition, and contain from 

 thirty to forty per cent. fat. The cream with a high 

 fat content requires less labor and vat room, is more 

 easily and exhaustively churned, and can be churned 

 at a lower temperature, thus producing a better quality 

 of butter. Many buttermakers make the mistake of 

 having the cream too thin or with too much skim-milk 

 in it. If at any time during the run the feed of the 

 milk to the separator is shut off, the bowl should be 



