76 THE DAIRY OF THE FARM. 



now that no torture or violent rapidity of movement is 

 required for this purpose that the texture of the butter 

 ultimately is rather injured than otherwise hy what may be 

 called a destructive violence or rapidity of movement. The 

 butter being removed, as already said, is dealt with by a 

 worker, which in all its many forms is essentially just a 

 deeply corrugated cylinder made to press and roll over the 

 butter on the table, where it is submitted to this kneading. 

 The machine which has produced and will produce 

 the greatest change of practice in our butter dairies is the 

 centrifugal cream separator. Of this, too, several forms 

 exist, all of them acting by a substitution for the force of 

 gravity in separating the cream, which is the lighter 

 portion of the contents of the milk, the action of a centri- 

 fugal force which can, of course, be raised beyond that of 

 gravity to any extent by increasing the velocity of revolu- 

 tion. The whole milk as brought from the cow pours 

 continuously into an enclosed flattish cylindrical vessel, 

 capable of holding 2 or 3 gallons. This revolves from 

 3,000 to 6,000 times a minute, and the water of the milk 

 carrying curd and sugar in solution, flies to the outer rim 

 of the revolving mass, the cream collecting in the centre ; 

 and each, as the whole milk continues to pour in, passes 

 into the tube properly placed to receive it, and is delivered 

 at its separate exit: a rich thick cream pouring from 

 one, and the poorest skim-milk veritable " sky-blue " 

 pouring from the other. Skim-milk may thus be had 

 " fresh from the cow; " and it will no doubt command the 

 value which really belongs to it as food, now that it can be 

 had unspoiled, as hitherto it has been, by the know- 

 ledge that it is 36 or 48 hours old, and is on the eve of 

 becoming sour. 



