FORGED IRON VESSELS. l97 



diameter to a foot, tlie workman disposes them in parcels, of Fabrication of 

 which each cont*ains four of equal dimensions, and then carries ^^ ^^^^ f^j. (,„_ 

 one of them to the hearth of the furnace, where the assistant linaryandoiher 

 lakes them in the large tongs. Fig. l,Pi.VI, and puts them into "**^' 

 the fire, taking care to change their position often ; and when 

 the brass is red hot, the master workman, who holds a small 

 pair of tongs in each hand, carries it under the tilting hammer, 

 after having spread charcoal powder between the plates, to pre- 

 vent their welding together. The two pair of small tongs have 

 the form of Fig. 2, and are used to give a circular motion to the 

 parcel, and to keep it on the anvil- When he has finished 

 hammering it, he changes the order of the four plates, and in 

 making this change, he is careful to take notice whether any 

 of them have cracked ; and where he perceives any crack, he 

 applies the cold chizel, or a wedge to the place on which the 

 assistant gives a blow. 



After having changed the situation of the plates in such a 

 manner that the two outside plates become the interior ones, he 

 places this parcel on the hearth, and takes another set, which 

 the assistant has caused to be heated, and he subjects this fo the 

 same operation of the ]-c-mmer. In this manner the process is 

 conducted until the required dimensions are obtained, namely, 

 after five or six heatings. 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 covered 

 with a mixture, formed of the oxide of lead and 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 seerj 

 practised. Either of these will prevent the plates from weld- 

 ing together, and for that purpose it is that they were applied. 



Forging the Cake. 



The workman takes seven plates of the same size, coated as 

 before described, with the oxide 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, 



T 3 When 



