On the Manufacture of Tin-plate. 365 
of melted metal soon melts all the loose tin on 
the surface of these plates, and so deteriorates 
the quality of the whole mass, that it is usual, 
when sixty or seventy boxes have been washed 
in the grain tin, to take out the quantity of 
a block, say three hundred weight, and re- 
plenish the wash-pot with a fresh block of 
pure grain-tin. These vessels generally hold 
three blocks each, or about half aton weight 
of metal. That which is taken out of the 
wash-pot when ‘it is replenished with pure 
metal, is given to the tin-man to put into his 
pot. | 
When the plates are taken out of the wash- 
pot, they are carefully brushed on each side 
with a brush of hemp of a peculiar kind, and 
made expressly for the purpose. As this part 
of the business requires considerable adrvit- 
ness and expedition, it may be worth while to 
explain it a little more in detail. 
The wash-man first takes a few plates out 
of the wash-pot, and lays them together be- 
fore him on the stow,—he then takes one 
plate up with a pair of tongs, which he holds 
in his left hand, and with a brush held in his 
right hand brushes one side of the plate—he 
manufactories, is used in the first process, viz., that ine 
is called tinning. 
