REFRIGERATION OF DRESSED POULTRY IN TRANSIT. 35 
The ice hunker. — Looking into the future through the glasses of the 
present, one sees trains of classified freight supplied with refrigeration 
from a portable, mechanical source. Until that dream is a reality 
it behooves us to raise the work of the ice bunker to its maximum 
capacity. The types of bunker most commonly used are sketched 
and described in this report. The most efficient would seem to be an 
emphatic indorsement of simplicity of construction based upon a 
sound scientific foundation. We know that abundant air access to 
ice and salt results in increased efficiency; hence the principle of the 
wire basket is sound. We know also that the brine resulting from 
the solution of the salt in the melted ice contains available cold; hence 
the holding back of the brine in the tank bunker increases the ability 
of the bunker to chill the car. 
Equality of temperatures in iced cars. — A serious shortcoming of the 
present types of refrigerator cars is their almost universal inability to 
equalize the temperature at the center and at the bunker, keeping 
both sufficiently low. Undoubtedly good bunkers and additional 
insulation, assisted by a stowing of the load in such a way that run- 
ways for cold air are left between packages, will materially help to 
improve results, but whether these remedies will suffice is still an 
open question. 
Fortunately for the preservation of the poultry shipped, the well- 
cooled package does not show fluctuations of temperature correspond- 
ing to those in the air of the car. A long-continued increase of tem- 
perature, or a direct contact between the package and the source of 
the heat, as, for example, the wall of the car, affects the temperature 
of the goods in the course of time. Sometimes the packages show' 
slight evidences of the daily rise and nightly fall of temperature, but 
more often it is the gradual but constant or maintained rise in the 
temperature of the car that is responsible for the objectionable 
results seen at the expiration of the haul. 
Future work. — The investigation which is here chronicled is only a 
small beginning in the solution of the problems confronting the 
shipper, the carrier, and the receiver in the handling of refrigerated 
perishable products. It is eminently necessary that such questions 
as the most efficient and economic size of the refrigerated car, the 
exact amount of insulation required to insure the maintenance of low 
temperatures, or, conversely, to protect the contents of the car 
against frost, the equalization of temperatures in all parts of the car, 
and many others, be pressed for more exact and far-reaching answers. 
It is hoped that the present report will stimulate further research in 
these and in other directions. 
ADDITIONAL COPIES of this publication 
-£*. may be procured from the Superintend- 
ent of Documents, Government Printing 
Office, Washington, D. C, at 10 cents per copy 
