Iron o 
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this manner the process is conducted until the required 
dimensions are obtained, namely, after five or six heat- 
ings* He then places the plates on the ground to cool ; 
and when cold, he cuts them circularly one at a time, with 
the large hand-shears, Fig. 3. 
This being done, each face of the plate is severally co- 
vered with a mixture, formed of the oxide of lead and the 
oxide of tin, pulverized and mixed with a little water ; or, 
instead of this mixture, clay, diluted in water, may be 
used, as I have seen practised. Either of these will pre- 
vent the plates from welding together, and for that pur- 
pose it is that they were applied. 
j Forging the Cake . The workman takes seven plates 
of the same size, coated as before described, with the ox- 
ide of lead and tin, and he places them upon each other. 
These seven being placed on two others of larger size, 
constitute what is called a cake, which is put into the fire 
by means of large tongs, not differing from the former*, 
except in the mouth, or claws, which are rather higher 
and curved, as is seen in Fig. 4. 
When the cake is red hot, the assistant, who always 
has the management of the fire, takes it to the edge of the 
furnace, where the master workman bends the two large 
plates in one part, and takes up the cake with the tongs 
already mentioned, Fig. 2. when he carries it to the anvil of 
the small forge hammer, in order to bend the edge of the 
two great plates entirely round. The difference between 
the diameter of the great and small plates, is about two 
inches ; when this is done, he puts the cake again into 
the fire ; and when red hot, he carries it to a smaller caking 
hammer than that used before, but fixed and moved 
in the same manner. The anvil is a rectangular parallel, 
opipedon, which rises above the ground not more than one 
foot ; and it has three pieces of iron bended to a right an- 
gle, at the height of the angle, which affords three branches 
