THE SALMON AND SALMON EISirERIES OF ALASKA. 
2 !) 
and as it comes from the trough it is i)laced on a table where Chinese seal by hand 
the central vent, which was left open in the capping process and in the soldering 
machine, where it becomes (^uite hot, to let the air escai^e. 
After the central vent is closed the cans are placed vertically in single layers in 
large open-work trays made of heavy strap iron and holding two cases. The filled 
trays are now lifted by tackles and iron tongs and lowered into a S(iuare woodeu tank 
filled with water heated by steam. This is the first test for leaks. Tiie experienced 
eye of the Chinese tester at once detects a faulty can by the escape of air, and the can 
is removed with a pair of tongs and placed aside, where one or more solderers remedy 
the defects. After removal from the hot-water test the trays are placed one on top of 
another ou cars, and are carried by a railway into the retorts for the first cooking. 
Cooliug a day’s pack. 
The cooking is all done by steam in a part of the cannery called the “bath-room.” 
In some canneries the retorts for first cooking are made of heavy plank, well bolted to 
resist the steam pressure, but in most places they are made of iron or mild steel plate. 
In the early days the cooking process was a grave secret and none but those interested 
in the cannery were intrusted with it. 
The time of cooking differs somewhat in different canneries, according to the ideas 
and experience of the superintendent. It is desired to not only cook the fish, but the 
bones must be cooked so they will crumble between the fingers, as if this is not done 
the contents may si)oil. In some establishments the canned fish is tiO minutes in each 
retort, in others 50 minutes in the first and from 70 to 80 minutes in the second. 
The trays with the hot, steaming cans, bulged out at the ends by the steam within, 
are then placed ou tables where the bath-room men test the cans by the process known 
as “ blowing ” or “ venting.” These men, armed with small woodeu mallets, having 
ou the broad face an awl-like i)oiut, tap rapidly the top of one can after another, 
