TRANSPORTATION OF CITRUS FRUIT FROM PORTO RICO 7 
concerned, tests were made of three different methods: (1) Stacking 
the fruit with dunnage in every layer, (2) stacking with dunnage in 
every other layer, and (3) without dunnage. 
THE FIRST TRIP 
On the first trip from Porto Rico to Xew York with citrus fruit 
the loading began at Ponce on September 23. The day before the 
fruit was taken aboard the refrigeration machinery was started and 
the holds cooled down. Prior to this the air temperatures in the hold 
were 70° F. at the bottom and 78° at the top. The temperature of 
the fruit received at this point averaged 80.7°, and the average 
temperature of the fruit loaded from all five ports — Mayaguez, 
Aguadilla, Ponce, Arecibo, and San Juan — was 80.4° F. The fruit 
was loaded six layers high on this first trip. 
Two holds were loaded, Xo. 2 between-decks and No. 1 between- 
decks. The arrangement of resistance thermometers for these two 
holds is shown in Figures 3 and 4. These illustrations show the loca- 
tions at which air and fruit temperatures were taken in the hold. 
An attempt was made in installing these temperature-measuring 
instruments to get temperatures representing the extreme conditions 
in the hold and also to obtain as nearly as possible a complete story 
of the temperature changes in the various sections of the hold. 
In cooling down the fruit it is necessary not only to take out the 
initial heat but to take care of any heat that may enter the hold 
through the insulation or through any openings. It is seldom pos- 
sible to fill a hold completely at one port; therefore it is frequently 
necessary to open the hatches or the side ports after some fruit has 
been placed in the hold and is partially cooled down. Some data 
were obtained in these experiments on the effect of this opening of 
the hold so that warm air could enter after the hold had been refrig- 
erated for some time. As shown in Figures 5 to 7, which give the 
average air, fruit, water, and brine temperatures on the trip, the 
fruit temperatures were slowly reduced. On the first reading 
(fig. 6), which took place 12 hours after loading was begun, the fruit 
showed an average temperature of approximately 74° F. At the end 
of the trip the average fruit temperature was 54°, a reduction of 20 
degrees in a period of eight and one-half days, or about 2.35 degrees 
F. per day. 
In Figure 7, which gives data on fruit loaded at San Juan only, 
the second reading showed a temperature of 82° F. : and in four days, 
the time from the first to the last reading, the temperature was re- 
duced to 57°, a total of 25 degrees of heat removed from the fruit, or 
6.25 degrees F. per day. 
There is a difference of about 5 degrees in favor of the fruit in 
No. 1 between-decks, Figure 7, and Xo. 2 between-decks. Figure 6. 
Although the fruit in Xo. 2 between-decks was under refrigeration 
for a much longer period, the fruit in Xo. 1 between-decks shows a 
more rapid cooling, OAving to the operation of the equipment. 
Referring to Figures 5 and 6, it will be noted that the brine tem- 
peratures show considerable fluctuation, which affects the temper- 
ature of the air in the suction or mixing chamber and in turn the air 
entering the hold. It is noticeable that on the third day after load- 
