Mamifacture of Tin-Plate. 



147 



as the superintendent thinks necessary. If they remain in the 

 grease an hour, they are found to tin better than when a shorter 

 time is allowed them. 



From this pot they are removed, with the grease still adhering 

 to them, into the pot just before spoken of, which contains the 

 body of melted tin; and in this they are placed in a vertical 

 position. Three hundred and thirty-eight, or three.hundred and 

 forty plates are usually put into this pot at once ; and, for the 

 sake of their being tjioroughly tinned, they usually remain in it 

 one hour and a half; but occasionally more time is required to 

 complete this operation. 



When the plates have lain a sufficient time immersed in the 

 melted tin, they are taken out and placed upon an iron grating, 

 that the superfluous metal may drain from them ; but, notwith- 

 standing this precaution, when they become cold there is always 

 more metal found adhering to them than is necessary ; and this 

 is taken off by a subsequent process, called luashing. As this 

 process is rather complicated, it will be necessary to describe it 

 with some minuteness. 



In the first place, the wash-man 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 referring to the 

 following drawing, which exhibits the several vessels in the order 

 in which they stand in the manufactory, all supported by sub- 

 stantial brick work. 



L2 



