CHAPTER XIX. 



ICE, ICE HOUSE AND REFRIGERATOR. 

 ICE. 



Necessity of Ice. Where there is no equipment for 

 mechanical refrigeration, an abundant supply of ice be- 

 comes indispensable in making the best quality of butter. 

 A low refrigerator temperature can not be maintained 

 without the use of a great deal of ice. The increased use 

 of starters and pasteurizers also demands increasingly 

 large supplies of ice. 



Cooling Power of Ice. A great deal of cooling can 

 be done with a comparatively small amount of ice. This 

 is due to the latent or "hidden" cold in ice. Thus to 

 convert one pound of ice at 32° F. into water at the same 

 temperature requires 142 units of heat, or, in other words, 

 enough cold is given out to reduce the temperature of 

 142 pounds of water one degree Fahr. 



Source of Ice. Always select the cleanest ice available. 

 Lake ice usually proves very satisfactory. \\^here the 

 source of ice is at too great a distance from the dairy, 

 an artificial pond should be made upon ground with a 

 reasonably impervious subsoil and with a natural con- 

 cave formation. If such a piece of ground is flooded 

 with water during the coldest weather, an ample supply 

 of ice will be available in a very short time. 



Cost of Making Ice. Where ice can be obtained 

 within a reasonable distance, the cost of cutting, hauling 

 and packing should not exceed one dollar per ton. 



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