Il8 MADRAS FISHERIES BULLETIN VOL. Xill, 



A salmon cannery on the Pacific Coast (e.g., at Puget Sound, 

 Washington, United States of America) may have a capacity for 

 dealing with 10,000 cases (each of 48 one-pound or 24 two-pound 

 cans) per day, and with such speed that a salmon alive one minute 

 may, within 20 minutes, have been perfectly packed in a closed can 

 ready for processing, so that there is no possible chance for taint. 

 The premises are absolutely clean, as are also the operatives ; in 

 one known case the can-filling attendants are young women 

 compelled to wear clean uniforms, and washing gloves changed at 

 least twice a day; this is mentioned as suggestive of the thorough 

 cleanliness observed in all operations. The fish received alive from 

 the boats are at once beheaded, gutted, and well scrubbed with 

 brushes in running water; they are then sliced, usually by 

 machines, into convenient portions, and are then filled into the 

 cans, a slip of tin being placed on the top so as to prevent the pin 

 hole in the cover from being choked with fish during the soldering 

 process. The cans are then closed, the caps, which have a pin 

 hole in the centre, being pressed on and crimped tight by automa- 

 tic machines ; from the capper the cans roll first through a bath 

 where acid is smeared on the crimped edge, thence through a 

 trough of melted solder which adheres to the parts that have 

 received the acid flux, and finally through a cooling trough to set 

 the solder. At this point the pin-hole in the cover, which was left 

 to allow of the escape of the steam and air during the hot soldering 

 process, is quickly closed by a drop of solder, and the can then 

 passes to the testing bath of hot water, immersion in which at 

 once reveals any defect in soldering since the contained air heated 

 by the bath issues as a stream of bubbles ; defective tins are at 

 once removed and resoldered at the leak. The cans found to be 

 hermetically closed are now ready for the first cooking called 

 " exhausting " ; they are arranged on trays in crates or cars which 

 are lowered by cranes if the kettles are vertical or run in on rails 

 into the more usual horizontal retorts; here they are processed, 

 usually at about 225^ F., or 5 lb. pressure, for half an hour. An 

 open bath is sometimes substituted for the process, as the object is 

 chiefly to heat up the cans so as to permit of the subsequent 

 exhaustion of the air by venting and reclosing. On removal the 

 cans are rapidly vented to allow of the escape of hot air and steam, 

 by being struck with a mallet having a sharp point in the centre ; 

 this vent, through which steam, air, and a little fluid issue, is sealed 



