FLORIDA STATE HORTICULTURAL SOCIETY 
61 
high as an insulator against the transmis¬ 
sion of heat. For these reasons it takes, 
under favorable conditions, at least one 
hour to cool one orange from 85 degrees 
downward to 40 degrees. In order to fur¬ 
ther complicate the cooling process, this 
orange is now wrapped in a layer of pa¬ 
per, thus adding an extra layer of heat 
insulation and also creating a dead-air 
space between the orange and its wrapper. 
After this the orange is placed in a box 
with others and the loose paper of the 
wraps is carefully tucked between the sev¬ 
eral fruits, making it extremely hard to 
even force an air circulation through the 
packed box. 
These conditions have so complicated 
the situation that now, under the most fa¬ 
vorable circumstances, it will require 
about 6 hours to cool the several oranges 
in the box through the 85 to 40 degree 
range, and to this we must add another 
hour if the so-called “wad pack” is used. 
These last figures as to time are given for 
concentrated cooling effort on a single box 
and must be multiplied by at least three or 
four when a large number of boxes are 
stacked in a typical pre-cooling room. 
From the foregoing it can be seen that we 
have come up, step by step, from one hour 
to approximately one day and, with im¬ 
proper air pressure and distribution, to¬ 
gether with other minor details, it is easily 
possible to consume two days’ time in 
reaching a desirably low and uniform 
temperature. 
Pre-cooling carries with it many new 
responsibilities for the individuals or as¬ 
sociations who choose to adopt it. Under 
the standard refrigeration method as fur¬ 
nished by our common carriers it is cus¬ 
tomary to order an iced car, load it and 
await results. With pre-cooling, the en¬ 
tire order is changed. All that can be 
done to deliver the fruit to market in 
sound condition must be done before the 
car doors are sealed. First, the manage¬ 
ment is entrusted with properly pre-cool¬ 
ing the fruit to a desired temperature. 
Again, only such cars as are in good con¬ 
dition should be used, as cracks at door¬ 
ways, hatches and similar defects are sure 
to add elements of danger in transit. The 
proper amount of ice must be supplied be¬ 
fore the car leaves for its destination. If 
any one of these three items is neglected, 
the chances for sound delivery are less¬ 
ened and the process can soon become a 
heavy liability instead of a valuable asset. 
The fundamentals of pre-cooling as 
well as its possibilities have long been de¬ 
termined. Much work of an investiga¬ 
tional nature has been done by the United 
States Department of Agriculture, dating 
from 1907. Much of this work was done 
in California during a four-year study of 
conditions there and later the work was 
continued in Florida. In this investiga¬ 
tion it was practically determined that it 
was not commercially advisable to attempt 
pre-cooled shipments from California to 
the far eastern markets unless re-icing was 
done at least once in transit, this being 
made necessary by the length of time re¬ 
quired for the trip. Florida conditions 
are, as a rule, entirely different in that our 
principal markets are much nearer as re¬ 
gards both distance and time. During the 
last two seasons I am not aware of any 
pre-cooled cars that have been re-iced in 
