362 On the Manufacture of Tin-plate. 
for the sake of their being thoroughly tin- 
ned, they usually remain in it one hour and, 
a half; but occasionally more time is iieici 
to complete this operation. 
When the plates have lain a par rin time 
immersed in the melted tin, they are taken 
out and placed upon an iron grating, that 
the superfluous metal may drain from them 5 
but, notwithstanding this precaution, when 
they become cold there is always more me- 
tal found adhering to them than is necessary ;, 
and this is taken off by a subsequent process, 
called washing. As this process is rather 
complicated, it will be necessary to describe 
it with some minuteness. 
In the first place, the Reet yidiar prepares 
an iron pot which he nearly fills: with the 
best grain tin in a melted state—another pot, 
of clean melted tallow, or lard. free from. 
salt—a third pot with nothing within it but 
a grating to receive the plates—and a fourth, 
called the listing-pot, with a little melted tin 
in it, about enough to cover the bottom to 
the depth of-a quarter of an inch. The 
whole will however be better understood by 
should be nearly filled, to prevent their falling down—in 
which case they could not be got out, through so heavy 
a body of metal, without much difficulty. 
