120 U. S. BUREAU OF FISHERIES. 
zene 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. 
The industry soon outgrew the hand method of lacquering, and the 
process which for a number of years was universal in the trade and 
is still used by some canneries succeeded it. For this there are a 
number of rectangular box vats about 40 by 80 inches and 18 inches in 
depth, the number varying with the capacity of the cannery. ‘These 
are usually lined with galvanized metal and provided with a grid- 
iron-shaped iron frame, hung from a windlass or other tackle for 
lifting or lowering from top to bottom of the vat. The cans are 
loaded on this gridiron, being placed in an inclined position to allow 
the draining of the lacquer, and are lowered in the vat sufficiently to 
submerge them in the lacquer with which the vat is charged to a 
depth of 7 to 10 inches. The loaded gridiron is then raised to the 
top of the vat and the cans allowed to drain and dry before piling. 
This method, while being more effective in regard to the volume of 
work, was still of necessity a very slow and tedious operation. In 
damp or rainy weather, especially when it is not possible to open 
warehouse doors and windows, the gas arising from a number of 
these vats makes effective drying almost impossible. 
Another principal objection to this method of lacquering, which 
applied also to all earlier attempts, was the impossibility of obtaining 
an even coat of lacquer when the can was allowed to dry in any 
stationary position. There was also a large waste by evaporation. 
Notwithstanding repeated efforts at invention, however, it was not 
until 1901 that an effective machine for handling this difficult work 
was put on the market. The apparatus now in use by a number of 
canneries receives the cans on a revolving wheel fitted with rests for 
holding them while passing through the lacquer bath. From here 
they roll upon an endless chain which revolves the cans as they pass 
through a long box in which a hot blast dries them before they reach 
the end of the machine. The rotating or rolling motion given to the 
can after the lacquer bath, preventing the lacquer from draining to 
and consequently accumulating on any part of its surface, also has 
the effect of distributing the lacquer evenly and results in a clean 
and neatly finished can. The air blast facilitates the work of drying 
to such an extent that it requires only about two minutes after being 
deposited on the drying bed of the machine for the cans to be ready 
for handling, while the quantity of cans which can be handled in a 
day is vastly greater than by the old method. 
A few flat and oval cans are not lacquered, but are protected from 
rust by wrapping in tissue paper, over which the label is placed. 
Several of the largest operators have stopped lacquering the 
sides of the cans, depending upon the label to protect this portion 
from rust. Enameled ends are used, and, as these are bought from 
can makers, these operators are thus enabled to get away entirely 
from the dangers of lacquering. 
