386 Tin. 
conducted so nearly in the same manner as not to require 
a separate description. 
In the manufactures of tin-plate on the continent a 
quantity of copper is always added to the tin, but in very 
small proportion. The exact quantity is regulated by 
slight circumstances, which only experience can teach. 
It appears to be in general from one- eightieth to one hun- 
dred and twentieth of the tin. The copper prevents the 
tin from adhering in too great a quantity to the iron, and 
causes the superfluous part to drain off* more freely. T oo 
much copper gives a dull yellow tint. 
It appears that the method of flattening the bar into 
plate by cylinders is only adopted in this country, but in 
other places is done by the hammer. \Aikm. 
Upon this information, I would make the following re- 
marks : 
1st. Desirable as the manufacture of tin-plates would 
be in this country, we have as yet no iron plates, at all 
fit for the purpose : they are neither thin enough, or 
smooth enough, or pure enough. 
2dly. The manufacturer of tin plates in this country, 
must roll out his own iron from bars picked by himself \ 
or he will not have such as he can depend upon. 
3dly. The rollers must be of the very best quality ; 
otherwise they will not give the requisite thinness and 
smoothness to the iron plate. While the plate is rolled the 
rollers should be greased. 
There is at this moment tin enough in the United 
States to supply more than a twelve months’ consump- 
tion ; but on the calculations I have made, no person can 
commence the manufacture of tin plates prudently, under 
a capital of 10 or rather 12,000 dollars. He must find 
his own water or steam engine power ; he must find em- 
ployment for his surplus power, when he is not rolling 
