156 REPORT OF THE COMMISSIONER OF FISHERIES. 



which would otherwise be thrown away is utilized in this manner. 

 The men eng-ao-ed in putting- in "chips"'' also keep a sharp lookout for 

 cans that may be too light in weight, and occasional tests are made. 



Capping. — The next step in the process is the capping, or topping, 

 which is done by a machine set close to the end of the table previously 

 referred to. An endless belt, composed of rectangular pieces of 

 metal large enough for a can to rest on without falling while in 

 motion, coijveys the cans from the table to the capper. One man 

 places the cans on the belt and another follows them along, on the 

 watch for pieces of salmon or bones above the edge of the can. 

 Pieces of fish, if there be any, are jammed down flush with the top, 

 and the overhanging bones are cut off with a pair of scissors. On 

 reaching the machine the can passes under a cap holding- a top, which 

 immediately falls upon it with just enough force to put on the top 

 without injuring either. The can is then forced out from under the 

 capper by the rotation of the luachine, and the next capper is brought 

 around to receive another can. The machine is supplied with tops by 

 means of an iron chute. As the cans revolve they are carried under 

 a crimper, situated directly opposite the capper, and while one can is 

 being capped another is being crimped, after whicli it rolls out upon 

 a belt on its side, and is taken through the acid trough and thence to 

 the soldering machine. The capper is supposed to correspond in 

 speed with the filler. 



Soldering. — In the early days of salmon canning the tops and also all 

 other parts of a can were soldered by hand, a long and tedious 

 process, which has now given way to the soldering machine. This is 

 composed of an endless chain about 6 feet long, revolving around two 

 shafts situated at either end of an iron trough, under which the heat 

 is supplied. In the bottom of the trough is the solder, kept at 

 molten heat by the fire underneath. The cans are forced along the 

 trough by the chain in contact with their sides. Between the lower 

 part of the chain and trough is just enough room for a can to pass 

 without jamming. The cans enter the trough at an angle, their bot- 

 toms slightly inclined, which causes the top rim to be submerged in 

 solder, thus distributing it evenly all around the edge. This method 

 is superior to hand work. 



In passing through the trough the cans make about half a dozen 

 revolutions, which cause the tops to become very hot, and it is to pre- 

 vent them from being blown off by the pressure of the steam which 

 quickl}^ generates that the center hole in the top is made. The 

 "chip" previously mentioned prevents the hole from being choked 

 with salmon. 



Before the tops are sealed the edges must be treated with a solution 

 of muriatic acid. This is done in the same manner as the soldering; 

 that is, by being run through an acid trough. At no time are there 



