4 BULLETIN 17, U. S. DEPARTMENT OF AGRICULTURE. 
transporting perishable foodstuffs requiring more refrigeration than 
is needed for fruit, much that is of interest to the packer, the carrier, 
the middleman, and the consumer has been unearthed. It was 
observed, for example, that different lots of poultry having identical 
treatment before shipment, and approximately the same atmos- 
pheric conditions during the haul, and requiring the same amount of 
time to reach the market, arrived in widely varying states of preser- 
vation. The differences were attributable, apparently, to the type of 
car in which the journey was made. A study of the construction of 
the cars in use on different lines revealed a marked variation both in 
materials and in construction. Accordingly, those factors in car 
construction on which efficiency of refrigeration depends were studied, 
and the temperatures observed in the cars correlated, not only with 
the preservation of the produce but with the construction of the car 
as well. As was to be expected from previous work, the temperature 
of the air in the different parts of the 'car was found to vary within 
sufficiently wide limits to affect the stability of the flesh of the poul- 
try. For example, that next to the side walls was quite unlike that 
in the middle of the car. It was deemed advisable to obtain accurate 
data on such variations, as well as on the fluctuations hi the tempera- 
ture of the air in the car, compared with the temperature changes 
undergone by the poultry inside the packages. 
SCOPE OF THE INVESTIGATION. 
The experiments herein reported, covering the period between August, 
1909, and October, 1912, include 120 car-lot shipments of dressed 
poultry and aggregate 140,000 miles of haul. The hauls averaged 
between 1,000 and 1,500 miles, terminating almost invariably in New 
York City. No car was used twice, and six different car lines are 
represented. The weather conditions varied, because the work con- 
tinued from season to season, and the territor}' involved extended 
from western Iowa to central Tennessee. 
The treatment which the produce received before shipment was 
commercial, but represented the best methods in use. The cars were 
those ordinarily received by the packer and in no case was a special 
car used, nor was any difference made in the handling of the car en 
route because it was under observation. Indeed, the railroads in 
most instances did not know that the work was being done until 
after it was finished. The information obtained at the market center 
covered the usual routine of the unloading of the car, the holding of 
the goods by the wholesaler for a short period, and its further deten- 
tion by the retailer. In aU of this part of the work commercial 
surroundings and commercial routine prevailed; hence the facts which 
follow may be accepted as indicative of the results of the practices 
of that portion of the trade equipped to handle dressed poultry in 
car lots or in smaller quantities. 
