32 BULLETIN 908, U. S. DEPARTMENT OF AGRICULTURE. 
These experiments show that as a means of preservation in the 
transportation of the small sea herring, refrigeration is in every 
respect far superior to the use of salt. 
This is apparent from a com- 
parison of the physical condition of the two lots of fish at the different 
intervals of time, and is confirmed by the analytical results. 
The 
same degree of decomposition in the viscera and contents of the fish 
carried under refrigerator conditions as that found for the 8- to 10- 
hour period in the case of the fish in salt is not shown until the end 
of from 25 to 30 hours. 
The difference between the appearance of fish transported under 
refrigeration and that of those carried an excessive length of time 
in salt is shown in Plates XII and XIII. Kept in compartments 
surrounded with ice and salt they are plump and firm, and look like 
_ fresh fish, even after they have been 30 hours out of water. 
The 
fish carried an excessive length of time in salt, in bulk, are poorer in 
appearance, and much thinner, and have been pressed out of shape. 
- Each lot of fish at the time of capture varies in the amount and 
kind of food in the digestive tract, and also in the bacterial con- 
tamination of the digestive tract. 
The keeping qualities, or the rate 
of decomposition, of different lots of fish should therefore vary 
directly as the contamination and quantity of feed vary. 
That 
this is true is shown by the differences in the time and extent of 
spoilage of the various lots of fish employed in these experiments. 
TEMPERATURE CHANGES OCCURRING IN LOADS oF FisH DURING TRANSPORTATION. 
Temperature observations were made on boatloads of fish trans- 
ported from the weirs to the canneries in pickle and in dry salt. 
It 
was estimated that the fish in the three lots studied contained dif- 
ferent proportions of feed. The results are given in Table 11. 
The 
temperature measurements were accurately made by means of a 
Leeds and Northrup potentiometer, the thermocouple of which was 
inserted in the mass of fish in the boats, and readings taken at the 
time intervals indicated. The temperature changes of the air on 
the warmest day of the month and the changes shown from the 
- Mean temperatures for the month in which these observations were 
made are included in the table. 
TaBLE 11.—Temperature changes in loads cf fish during transit. 
FLOATED IN BRINE se 150 POUNDS OF SALT PER HOGSHEAD OF FISH; 
LIGHT AMOUNT OF FEED PRESENT. 
Temperature. 
Time 
observed. 
a. 
30 
8.00 
Of air.1 
Warmest | Mean for Of fish. 
ay. month. 
6 “AGS oes 
PET; 6.9 12 
L Sas Co So ee eee 13 
Pree ah ea [aes See ee. 3 15 
13.8 &.2 16 
1 From hourly thermograph readings taken from original monthly record of observations at Eastport, 
Me., for October, 1916 (courtesy of U. S, Weather Bureau). 
