132 



SCIENCE AND PRACTICE OF DAIRYING. 



28 -8 centimetres, and a continuous flange inside. In the case of No. 2 

 the drum is somewhat higher. The milk which comes in falls through 

 the top opening of the drum into a cup 5*2 centimetres wide, resting 

 upon the foot of the drum, and flows from this to a tube under the layer of 



cream, formed dur- 

 ing the operation. 

 The cream runs 

 outwards through 

 a narrow, shallow 

 slit in the side of 

 the neck of the 

 drum, and the skim- 

 milk through a tube 

 leading up from 

 the widest part of 

 the drum, then 

 through a small 

 opening about half- 

 way up the neck of 

 the cylinder, which 

 can be set, when 

 the drum is at rest, 

 either narrower or 

 wider, and of course 

 each liquid by itself 

 runs into a special 

 circular-shaped re- 

 ceiver at the top of 

 the cover. A simple 

 indicator, which is 

 placed in the well, 

 renders it possible 

 to determine the 

 rapidity of the re- 

 volutions of the 

 drum per minute. 



Fig. 35. Alpha Separator No. 1. (Perpendicular Section.) 



(6) De Laval Hand-separators. Dr. De Laval devised the first 

 useful hand-separator in 1886. At present two such machines are 

 made, the separator (K), which has a horizontal cylindrical drum, 

 and the Baby separator, which has a vertical cylindrical drum. 

 The drums of both these separators have short cylindrical necks, 



