112 
Journal of Agricultural Research 
Vol. XXIX, No. 3 
the low temperatures for the longest 
time. Consequently their initial tem¬ 
perature was lower and continued so. 
There seems to have been no consid¬ 
erable warming of the fruit in the 
upper layers by heat given off from 
apples in the interior of the box. The 
data are plotted in Figure 3 for only 
120 hours, but the experiments were 
carried on for 12 days. At the end of 
this time the maximum drop from the 
freezing point in the bottom of the 
box of unwrapped fruit was only 1.5° 
F. In some instances, as for example 
the center of the box of wrapped 
apples, the temperature reading at 12 
days was practically the same as it had 
Figure 2. This is true also of the 
graphs for temperature changes in the 
boxes of wrapped and unwrapped Wine- 
sap apples compared with similarly 
handled York Imperial apples. No 
temperature readings were made in the 
centers of boxes of the latter. The data 
given in Figure 7 are for both wrapped 
and unwrapped York Imperial apples. 
It should be noted that the discrepancy 
in position of the temperature graph 
for the top of the box of wrapped 
Winesap apples is found only for a 
short time in the case of the York 
Imperial, after which the heat from the 
center of the box probably warmed the 
upper layers so that the temperature of 
Fig. 5.—Comparison of the temperatures obtaining in the center of the box of wrapped, in the^ 
box of unwrapped, and in the barrel of unwrapped Winesap apples during exposure to external Ji 
temperatures around 25° F. for 120 hours 
been at 64 hours, indicating that ice 
formation in the fruit hud been going 
on with the production of heat of 
fusion in amounts sufficient to offset 
the heat loss to the colder exterior. In 
nearly all cases, the temperature drop 
at the end of 12 days was a fraction of 
a degree below the temperature at 
which the fruit had been for a long 
time and which was apparently the 
freezing point. 
Figures 6 and 7 present the data for 
the York Imperial apples packed and 
handled similarly to those of the Wine¬ 
sap variety. The graphs for the tem¬ 
perature changes in the fruit in the 
barrel closely resemble those shown in 
the top of the box thereafter was higher 
than that of the bottom. 
Another series of experiments was 
carried on with a freezing-room tem¬ 
perature at or below 20° F., with gen¬ 
eral results similar to that at 25° F., 
the important difference being that the 
interior temperature of the packages 
drops more rapidly at the lower freezing 
temperature. Figures 8 and 9 give the 
results obtained for the two barrels of 
apples, Winesap and York Imperial, for 
a period of 96 hours. The fact that 
during the first few readings fruit in the 
top of the barrel is apparently colder 
than fruit in the center or at the bottom 
of the barrel is probably due to inci- 
