HAXDLIXG LETTUCE AXD CELERY. 19 
as well as slow. The crates generally are spaced an inch or two apart 
in order to facilitate the circulation of air, but even greater spacing 
would be by no means sufficient to equalize the rate of cooling 
throughout the car. The heavier cold air settles in the lower part 
of the car, and the entire lower layer therefore cools off rather quickly, 
though not as rapidly in the center as near the ice bunkers in each end. 
The upper layers, especially the top tier,, cool off more slowly. This 
fact is particularly noticeable in cars that have been closed for only 
a few hours after being loaded. When the doors in these cars 
are opened the air near the floor feels cold, but that near the ceiling 
is often unbearably hot. This heat sometimes causes serious damage. 
The leaves turn light yellow, and as this injures the appearance of 
the celery and is recognized on the market as an indication of lessened 
vitality, crates containing celery with yellow tops are discounted 
accordingly. In general practice, when the car is unloaded the crates 
from the top of the load are purposely. mixed with the more attractive 
crates of the lower tiers, in order to make them sell at a fair price. 
If the celery in the top crate is very yellow, however, the entire ship- 
ment is discounted 25 to 50 cents per crate below the price which 
it would have brought had there been no "yellow tops." 
Celery from the Manatee section of Florida is shipped largely in 
crates 12 inches in depth. This is regarded as the standard crate 
in that section. In other localities, notably around Sanford, the 
10-inch crate is the standard. The minimum freight rate is quoted 
on 350 crates regardless of size, and when the larger crate is used 
this number makes a load that reaches within 8 or 10 inches of the 
top of the car. Naturally, it is more difficult to lower the tempera- 
ture in this car than in a car loaded with the 10-inch crates, where 
more space is left between the top of the crates and the roof of the 
car. In both cases, however, there is often serious damage due to 
slow cooling. In this connection, attention should be called to the 
desirability of the adoption by the growers of a standard-sized crate 
for all sections of the State. 
OUTLINE OF CELERY-PRECOOLING EXPERIMENTS. 
In order to determine the effect of precooling upon the temperature 
of the celery while in transit, two experimental cars were procured 
in March. Twelve electric thermometers were placed in various 
parts of the load in each car as in the case of the lettuce cars, and 
one of the cars was precooled. The bunkers of the precooled car 
then were topped off sufficiently to replace the ice that was lost 
by melting during the time it was being loaded and precooled, but 
no more ice was added during its entire trip. The other car was 
shipped in the usual manner, i. e., under full refrigeration. In 
