TRANSPORTATION 141 
facts: (1) The box system is more cheaply installed 
and operated, and (2) the fruit is more easily cooled 
down before loading in the cars than it is afterwards. 
The car system of pre-cooling is so expensive that it 
can only be installed in centers of production or at the 
best shipping points. In such cases it is necessary to 
load the fruit into the cars during the day or evening 
Fig. 105.—-PACKAGES OF FRUIT READY FOR THE POSTMAN 
from each of the warehouses and then run direct to the 
different cooling plants. Here they are cooled down 
during the night, and in the morning sent off on their 
journey. This means that from 5 to 24 hours must elapse 
from the time the fruit is placed in the cars until it is 
properly cooled down for shipment. In the hot climates 
of the South and the West this has been found to be too 
long,a time. 
The principle on which these pre-cooling plants oper- 
