DAIRY AKD SEED IMPROVEMENT MEETINGS. 209 



Chilling the milk takes place in the milk room, and therefore 

 the milk room has one of the most important functions to per- 

 form in the production of clean milk. In fact, unless the milk 

 is chilled, no amount of cleanliness in the cow barn can prevent 

 enormous bacterial growth. The washing of the cow keeps the 

 original number of bacteria small, and the chilling of the milk 

 prevents them from increasing in number. 



To get down to the milk room proper : The first and primary 

 consideration is a good, efficient cooler. The ordinary forms of 

 cooler on the market depend on running the milk in a thin 

 layer over metal cooled by either flowing water or ice water. 

 If a man has a source of very cold spring water, and will let 

 this flow in a large stream through a cooler, it will give him 

 pretty satisfactory results. If a man depends on ice water, in 

 order to get much efficiency he must keep the water constantly 

 stirred. 



In the ordinary, round, conical shaped milk coolers I have taken 

 a good many temperatures of the milk. When the ice water was 

 stirred once in six minutes, which would be done by one man 

 stirring the ice water every time he entered the milk room to 

 dump a pail of milk, the temperature in the can was about 65 

 to 70 degrees, not nearly cool enough to arrest the growth of 

 bacteria. If the ice water inside the cone was not stirred at all, 

 the milk ran into the can at the bottom at 73 or 75 degrees, 

 there being only from 28 to 35 degrees of animal heat taken 

 out. If the ice water was stirred continuously and vigorously 

 by a man constantly there, the milk ran out at about 38 degrees, 

 in which case 60 degrees of animal heat were taken out. The 

 temperature of 38 degrees is plenty low enough, and the increase 

 in bacteria in twenty-four hours would be hardly perceptible at 

 this temperature. 



It is, however, impractical to hire a man for the special pur- 

 pose of stirring ice water during milking time. This can be 

 done in many ways more cheaply : A small gasoline engine 

 such as is used to run wind mills, costing about thirty-five dol- 

 lars, can be installed to do this. The cost of operation of one 

 of these engines is surprisingly small. A tumbler full of gaso- 

 line will run an engine of this sort for ten hours, and it is easy 

 to rig such an engine as this to stir the milk in a conical cooler. 



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