REFRIGERATION OE DRESSED POULTRY IN TRANSIT. 13 
low-temperature shipments increased to 0.0144 per cent, nearly the 
same as the high-temperature shipments at the end of the transit 
period. In other words, if the car temperature is above 35° F. the 
poultry when it reaches the market has the disadvantage of a dete- 
rioration equivalent to five or more days in the market, and to be in 
the same state of freshness it must be consumed five days earlier than 
that arriving at car temperatures below 26° F. 
These results give some idea of the effect of small differences in 
temperature on poultry during the market period and indicate that 
the most favorable temperature for poultry transportation is 30° F. 
or below. It therefore becomes a fundamental problem in the 
transportation of dressed poultry and similar products to maintain 
low temperatures in all parts of the car, which finally resolves itself 
into a question of car construction. 
REFRIGERATOR CARS. 
SOURCES OF DATA. 
The shipments already described and tabulated in Table 1 were 
hauled by six different car lines. The cars were of so many different 
series that they furnished a great variety of sizes, insulations, roofs, 
doors, ice bunkers, and all of those elements which are factors in 
the sum total of efficiency. 
The car number, the amount of ice and salt used in the initial 
icing, the temperature of the car before and after loading, the posi- 
tion of the thermographs, the prevailing atmospheric temperature 
and weather conditions, the re-icing instructions, and the route were 
all noted at the time of loading. A record of the movements of the 
cars and the time and amount of ice and salt used in re-icing has 
been generously furnished by the railroad companies. The railroads 
have also greatly facilitated this study by freely providing detailed 
blue prints showing the construction and insulation of the cars in 
which the experimental shipments were carried. 
In some of the experiments the atmospheric temperature was 
obtained by a thermograph fastened to the outside of the car. In 
the majority, however, the average between the maximum and mini- 
mum atmospheric temperatures was taken each day for the region 
through which the car was passing, as shown by the daily weather 
maps and monthly reviews issued by the United States Weather 
Bureau. The temperature records obtained in this manner coincide 
almost exactly with those obtained by thermograph on the outside 
of the car. The inside car temperatures during transit were obtained 
by thermographs. (See Table 4.) 
