TANKS OF STILL WATER 69 
water. Farm springs may have temperatures in 
the summer time from 50° to 60°. Where water 
runs ‘by gravity or through the operation of a 
pump, the temperature of the milk in such tanks 
can be kept as low as the lowest temperature of 
the water, and milk can be cooled without stirring. 
TANKS OF STILL WATER 
Where dairies have no running water and no 
ice, and must depend upon tanks which have been 
filled from a pump or a well, the best results can be 
secured by stirring the milk. Such stirring will 
bring milk to the temperature of the water in 
about half the time required to reach such a tem- 
perature if unstirred. Under these conditions, the 
stirring of night’s milk is particularly necessary 
in summer time. Stirring rods should be of smooth 
metal and not of wood. 
MORNING’S MILK AND NIGHT’S MILK 
When the dairyman delivers milk for shipment 
once a day, and the time selected is the morning, 
morning’s milk is twelve hours newer than night’s 
milk. The cooling of night’s milk is then far 
more important than the cooling of morning’s 
