COOLING, STORING, AND SHIPPING MILK. 



9 



four tests. Table 1 shows the B. t. u. absorbed under the different 

 conditions : 



Table 1. — B. t. u. absorbed by water and tanks under different conditions. 



Typo of tank. 



Outdoors. 



Uncovered. Covered 



Indoors. 



Uncovered. Covered 



Galvanized iron 



Concrete 



Wood 



Insulated 



B.t.u. 



24, 200 

 19, 800 

 15,400 

 11,550 



B.t.u. 

 15,950 

 12, 650 

 5,500 

 1,650 



B. t. u. 

 15,400 

 11, 550 

 7,150 

 4,400 



B. t. u. 

 12, 100 



4,400 

 1,100 



Table 2 shows the relative loss of efficiency in cooling tanks of dif- 

 ferent construction compared with the insulated tank. 



Table 2. — Relative loss of efficiency in cooling tanks of different construction, 

 based on tlie insulated tank as unity. 





Type of tank. 



Outdoors. 



Indoors. 





Uncovered. 



Covered. 



Uncovered. 



Covered. 





2.1 

 1.7 

 1.3 

 1 



9.7 

 7.7 

 3.3 

 1 



3.5 



2.6 

 1.6 

 • 1 



11 





8 



Wood 



4 





1 







The relative loss of cooling effect in tanks of different construc- 

 tion expressed in pounds of ice is shown in Table 3. This table also 

 emphasizes the range of loss in cooling effect through radiation from 

 cooling tanks during hot weather. 



Table 3.- 



-Relative loss in cooling effect in tanks of different construction ex- 

 pressed in pounds of ice. 





Type of tank. 



Outdoors. 



Indoors. 





Uncovered. 



Covered. 



Uncovered. 



Covered. 



Galvanized iron 



Pounds. 

 168 

 137 

 107 

 80 



Pounds. 

 Ill 

 88 

 38 

 12 



Pounds. 

 107 

 80 

 50 

 30 



Pounds. 



84.0 



61.0 



30.5 



7.6 



Concrete 



Wood 



Insulated 





The galvanized-iron tank, without a cover and exposed to the 

 direct rays of the sun, lost 168 pounds of ice compared with 7.6 

 pounds of ice for the cork-insulated tank covered and sheltered, or a 

 difference of 160.4 pounds of ice. A loss of this amount of ice each 

 day for 150 days would amount to approximately 24 tons for the 

 season. At that rate, in 150 days the loss of ice, estimated at 15 



81238°— Bull. 744—19 2 



