TRANSPORTATION 143 



houses of each of the local exchanges and draw fruit 

 from the area from which the exchange operates. 



The fruit is cooled down as soon as it is brought in 

 from the orchard. After being sufficiently cooled, it is 

 stored in a cold room or loaded directly into the cars and 

 sent off. Before the inauguration of the pre-cooling 

 plants, cars of fruit moving north or east during the 

 hot season would need to be iced every four days. In 

 some cases, every three days. This would mean a stop 

 of from two to six hours at certain icing stations along 

 the road to refill the bunkers of the cars. As the rail- 

 road companies always charge extra for this it adds very 

 materially to cost of transportation of the fruit. 



Pre-cooling plants, for the most part, cool the fruit 

 down sufficiently before starting so that the initial icing 

 is sufficient to carry the fruit across the continent, thus 

 making a saving both in expense and time in transit. 

 In some cases pre-cooling is working so satisfactorily that 

 fruit can be shipped across the continent without any 

 ice in the bunkers. 



In the car system for pre-cooling fruit sufficient cool- 

 ing space and track surface is necessary to accommodate 

 a full train of fruit consisting of about 32 cars. From 

 four to five hours are required to cool down the fruit 

 in these cars to a temperature of 45 degrees which is 

 considered desirable before starting them on their long 

 journey. The method of producing the cold is similar 

 to the ammonia pressure system referred to in connec- 

 tion with the large public cold storage houses. One of 

 the largest of these plants in California contains over 

 35 miles of pipe coils through which brine with a tem- 

 perature below zero is circulated. The air surrounding 



