156 REPORT OF THE COMMISSIONER OF FISHERIES. 
which would otherwise be thrown away is utilized in this manner. 
The men engaged 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, conveys the cans from the table to the capper. One man 
places the cans on the belt and another follows them along, on the 
vatch 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 machine, 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 which 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 hea 
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 
quickly 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 muriatie 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 
