SALMON FISHERIES OF PACIFIC COAST. 57 



few rubs with a brush over the top, removes from the can all the 

 grease and other material, and then passes them into another bath 

 where the lye is washed off in hot fresh water. The cans then go to 

 the cooling room, where a stream of water is played upon them, or, 

 during rainy weather are placed out of doors upon the wharf, and 

 there allowed to cool. 



The top and bottom of the cans contract in cooling, and for several 

 hours a sharp popping noise is heard. Here, as in nearly every proc- 

 ess through which they pass, the cans are again tested, this time by 

 tapping the tops with a small piece of iron about 6 inches long, or, 

 sometimes, a 12-penny nail. The sound conveys to the ear of the 

 tester an unmistakable meaning as to the condition of the can, and 

 the faulty cans that escape notice during the other tests are invari- 

 ably found in this one. 



LACQUERING. 



An almost universal custom in the salmon-canning industry, but 

 one that is not common in the canning of vegetables, fruits, etc., is 

 that of lacquering the cans. This idea of protecting the can on the 

 outside has been followed from the very beginning, for two reasons: 

 (1) That the English market which, at that time especially, absorbed 

 the greater part of these goods, insisted on their shipments being- 

 finished in this way, and (2) from the fact, as these canners speedily 

 found out, that if they did not protect their cans in some way enor- 

 mous losses through rust would ensue. 



The first experiment of this nature was to paint the cans by hand 

 with red paint, treating each singly. Next a composition of logwood 

 extract and alcohol was tried, which, however, did not produce satis- 

 factory results for a very plain reason — the can was dyed instead of 

 being lacquered. The next attempt was to varnish the cans with a 

 japan varnish reduced with alcohol, but this was found to dry too 

 slowly for speedy handling. After extended experimentation the 

 quick-drying brown lacquer of the present time was evolved, which 

 carries asphaltum in the form of an asphalt varnish as its base, this 

 being supplanted in some cases by gilsonite. This lacquer can be pro- 

 cured in either a heavy or light body, is generally reduced with ben- 

 zine or gasoline, and is applied according to the requirements of the 

 market, which in some localities demands a heavy coating and in 

 others a much lighter finish, the latter giving a rich golden brown 

 color. Some experiments have also been made in using brighter col- 

 ored lacquers for this work. Several of these, made to give a bright 

 golden, copper, or other color, are extremely attractive in appearance, 

 while at the same time protecting the tin against rust quite as well 

 as the brown. 



