COOLING HOT-BOTTLED PASTEURIZED MILK. 
was circulated, however, this drop in temperature was obtained in 
1 hour and 27 minutes, or in approximately one- third the time 
required for an equal drop in temperature when the bottles were 
exposed to still air. 
Kef erring to the two similar curves in figure 4, showing the results 
obtained with quart bottles of milk under the same conditions, it will 
be noted that the relative rate of cooling between the bottles exposed 
to still air and moving air is the same as that for pint bottles, except 
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Fig. 3.— Cooling in still air compared with forced air.— Relative drop in temperature between pint bottles 
of milk cooled in still and moving air. Velocity of moving air 1,250 feet per minute. 
that the quart bottles are uniformly higher in temperature than the 
pints for the same period of cooling. 
The curves in figure 5 show the relative drop in temperature of 
the milk contained in 10-gallon cans when placed in still air and in 
moving air. The air blast in this case was also furnished by a 16-inch 
electric fan which gave an air velocity of 1,250 feet a minute. The 
conditions were practically the same as those for the pints and quarts, 
except that the temperature inside the room averaged 42° F. 
(5.5° C.)i or 2 degrees higher. The temperature of the milk con- 
tained in the 10-gallon can, placed in still air, was reduced to only 
