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CIRCULAR 713, U. S. DEPARTMENT OF AGRICULTURE 



Figure 2. — Rate of cooling of wrapped and unwrapped lemons in a crate 

 not papered over the outside in an 18° F. room. Undercooling occurred in 

 the top layer at the side in both wrapped and unwrapped fruits, but the 

 rise to the true freezing point probably came between 4:30 in the afternoon 

 and 8:30 the next morning, during which time no temperature readings 

 were made. 



wrapped and unwrapped fruits in the middle layer at the end of 

 the box were frozen, while others were not. At the center of the 

 half box, unwrapped fruit began to freeze after 7 to 8 hours but 

 wrapped fruit did not begin to freeze until after about 24 hours. 

 After 75 hours at 18°, some wrapped and unwrapped fruits in both 

 ends of the box at or near the center position in each half were still 

 not frozen. 



(4) Two bags of rutabagas (1 bushel each) having starting 

 temperatures ranging from 54.9° to 59.3° F. were placed in an 18° 

 room. One of the bags remained motionless during the test ; the 

 other bag was shaken continuously on a jolting machine, to simu- 

 late conditions in a moving railroad car. The roots at the top and 

 sides of both bags began to freeze in about 7 hours. There was no 

 evidence that the jolting made any difference in the length of time 

 required for the roots to freeze. 



(5) New cabbage in bushel crates, having starting tempera- 

 tures ranging from 50.6° to 54.7° F., was held in an 18° room 

 under the conditions just described for rutabagas. Freezing oc- 

 curred at the top and around the sides of both crates in about 9 

 hours. There was no noticeable effect of the jolting. 



(6) New cabbage in a bushel basket and rutabagas in a bushel 

 bag were placed in a 25° F. room. Their starting temperature 

 was approximately 64°. The rutabagas began to freeze in 18 to 



