154 U. S. BUREAU OF FISHERIES 
the air, coils can be placed in front of the fan at C, between the trucks 
at Dand at FE. Fresh air can be made to enter at H and leave at J or 
elsewhere in the housing, as desired. If a furnace is used, heat can 
enter at H. The air will have to be correctly baffled along the sides 
at Cand F to get uniform air movement through the trucks. 
This system can be used with one or two lines of trucks. More 
than two lines of trucks, even with high-velocity air, will not give uni- 
form cooking on all trucks. As it is, with only two trucks, the fish 
on the edges facing D will not be cooked quite as well as those on 
the outer edges, unless coils are placed at D. This difference, how- 
ever, will give no trouble. 
Trucks for holding the flakes should be of metal and as lightly 
constructed as practicable. Under each flake there should be a 

Fic. 30 
light-weight, rigid, removable drip pan, which will not sag. The 
pan should be but 3% or 14 inch deep, so as to interfere as little as 
possible with the flow of air between the flakes. 
The flakes must be spaced on the truck so as to allow sufficient 
air at the right velocity to pass between them. For quarter-oil 
sardines a spacing of about 314 inches should be enough for each 
flake and its drip pan. The pan takes up about 14 inch and the flake 
about 1 inch, leaving 244 inches, which should be proportioned so as 
to have 1 inch of space under the flake and 114 inches above the fish. 
For pound-oyal fish a 4-inch space should be sufficient. It probably 
will be possible to get along with less free space, especially with the 
type of cooker shown in Figure 30. Possibly, too, drip pans may be 
unnecessary with quarter-oil fish. The above recommendations are 
safe ones, however. 
