DAIRY INSPECTION 187 
milk can be cooled down to 40° F., while with ammonia 
or brine it can be brought still lower, even to freezing.’ 
The cooler must be thoroughly cleaned each time it 
is used, stored in a clean place, and protected from dust 
while in operation, or the milk will take up large num- 
bers of bacteria during the process of cooling. When the 
cooler is not properly used and cared for, it has been 
found that better results can be obtained by pouring the 
milk directly into a shipping can and placing the can 
in cold water, although the temperature is lowered very 
slowly under these conditions, three to four hours being 
required for the temperature to fall to 60° F. In some 
cases it has been found more satisfactory to have the 
milk taken in cans to the shipping station and to cool 
it there. When this plan is followed the milk must 
reach the shipping station during the period the germi- 
1 In the northern part of the United States, about 114 tons 
of ice will be required each year to cool the milk obtained from 
each cow, while in the southern states about 2 tons will be 
necessary, allowing for the waste by melting. A ton of packed 
ice will occupy 40 to 50 cubic feet of space; 12 inches should 
be allowed on the sides and bottom for sawdust or other pack- 
ing material and 3 to 4 feet on top for packing and ventilation. 
With these figures, the dimensions of an ice house of any ca- 
pacity desired can be determined. A foot of packing material 
should be placed under the ice even when the ice house has 
an earth floor, earth being a fairly good conductor of heat, 
especially when wet. Water from the melted ice will usually 
drain off through the soil unless the latter is of clay, in which 
case it will be necessary to excavate 1 or 2 feet, put in a tile 
drain, and fill in with gravel or cinders. The pipe supplying 
water to the milk cooler may be run under the floor of the ice 
house with advantage. (A number of good plans for building 
ice houses will be found in the U. S. Department of Agriculture 
Farmers’ Bulletin No. 623.) 
