COOLING HOT-BOTTLED PASTEURIZED MILK. 3 



Thirty crates of bottles, stacked in six piles each five crates high 

 inside the box, were cooled at one time. Before the crates were 

 stacked on the platform the movable sections were removed, so that 

 the space under the crates was open and the rest of the platform 

 closed. By this arrangement it was possible to force all the air 

 directly through the crates of bottles. 



When air was forced up through the crates the operation was as 

 follows : Air was drawn by blower A through pipe B from the outside 

 of the building and forced through pipe C into the bottom of the 

 cooling box. From that point it was forced up through the piles of 

 crates and passed out from the top through pipe D. In this case 

 damper No. 1 in pipe C was open and damper No. 3 in pipe F was 

 closed, while damper No. 2 in pipe E was closed and damper No. 4 

 in pipe D was open. 



When air was to be forced down through the crates, and conse- 

 quently had to enter at the top of the box, it was necessary simply to 

 change the dampers in the pipes. To force air in at the top through 

 pipe E, damper No. 1 was closed and No. 3 opened; in the outlet 

 pipes damper No. 2 was opened and No. 4 closed. This system of 

 pipes and dampers would not be necessary for cooHng milk on a 

 commercial scale, but was necessary for experimental purposes. 



DESCRIPTION OF INSTRUMENTS AND METHOD OF RECORDING DATA. 



Temperatures ^ were determined with copper-constantin thermo 

 elements made from No. 30 wire, tested to the required degree of 

 accuracy for thermoelectric homogeneity. Junctions were soldered, 

 wound with sUk thread, and inclosed in thin glass tubes. Where 

 leads were exposed to steam or air blast the double-silk insulation was 

 protected by being incased in black-rubber tubiag. Each element 

 was composed of two pairs of couples in series. A calibration curve 

 for each element was constructed from the potential given when the 

 cold junction was immersed in a thermos bottle containing crushed 

 ice, and the hot junction was immersed (1) in melting ice, (2) in a 

 fusion of recrystallized sodium sulphate (Richard's point), and (3) in 

 steam at known barometric pressure. In each case the temperature 

 was also taken with a thermometer cahbrated by the Bureau of 

 Standards. From the calibrations so obtained deviation curves were 

 constructed and used with Adams's^ table. 



PotontiaLs were measured with a Leeds and Northrup potentiometer 

 and galvanometer. The potentiometer was cahbrated by the Bureau 



» We are greatly indebtefl to Dr. W. M. Clark, of the Dairy Division, for preparing, describing, and oper- 

 ating a system for temperature moasuroments l)y moans of thermocouples. 

 *Adamfl, L. H. Journal of American Chemical Society, 30, p. 05, 1914. 



