igf5 FORGED IRON VESSELS. 



VIII. 



Some Account of the Manufacture of Forged Iron yessels, at 

 Fromotit. By M. Ch, Hers art.* 



Fabrication of "^^ operations of forging vessels of cast iron may be 

 vessels of forg- divided into three distinct parts: 1st, the method of forging the 



cdiron, forcu- plates; 2d, that of forging the cake or parcel; 3rd, the cold 

 linaryand other r . ^^ , , ^, , . , 



uses. hammering Or those we shall speak in the order here men- 



tioned, which is likewise the order of fabrication. 



To Forge the Plates. 



The iron for this manufactory must be very soft and malle- 

 able. It has usually the form of bars, ten or twelve feet long ; 

 each bar having the form of a long truncated square pyramid. 

 This form is necessary in order to obtain plates of different 

 diameter. The small base is a square of ten lines, or twelfth 

 of an inch, and the greater eighteen lines. 



The assistant puts one of these bars in the fire, and when the 

 Jieated part is ignited, the master forgeman carries it to the 

 small tilting hammer, which is not different from those used ini 

 drawing out steel bars. He places the bar on the anvil, not 

 upon one of its faces, but on an edge, as, in this position, the 

 iron is less subject to crack. According to the size of the 

 plate intended to be hammered out, the workman strikes a 

 greater or less portion of the bar, presenting it in all situations 

 to the hammer, in order that the plate may obtain a circular 

 form. Betv/een the plate and the bar itself, he fashions a small 

 neck to facilitate its separation. In this manner, the workman 

 continues to forge the plate on both its faces as long as the heat 

 allows, after which he carries the bar to the anvil, and applies 

 a cold chlssel to the neck, upon which his assistant strikes in 

 order to separate the plate from the bar. This last is then re- 

 turned to the fire, in order to continue the operation in making 

 a second plate. Sometimes, but this is only when the plates 

 are small, the workmen make three at once. 



When a sufficient number of plates has been thus fabricated, 

 as they are of different sizes, namely, from three or four inches 



diameter 

 * Journal des Mines, No, 112. 



