Iron , 
31 $ 
is gathered into lamps and beaten with a heavy-headed tool. 
Finally, the tools are withdrawn, the apertures through 
which they were worked are closed, and the flame is turn- 
ed on in full force for six or eight minutes. The pieces 
being thus brought to a high welding heat are withdrawn 
and shingled ; after this they are again heated and passed 
through grooved rollers, by which the scoriae are separat- 
ed and the bars thus forcibly compressed acquire a high 
degree of tenacity. 
The more welding and hammering that bar iron is sub* 
ject to, the tougher it becomes and the more fibrous, or 
nervous as the French term it, is the fracture. Hence 
arises the superiority of Stub iron to all the other varieties 
for barrels of fowling pieces and other uses where extreme 
toughness is required. It is prepared in the following 
method. A moderately broad ring of the best Swedish 
iron is placed horizontally and filled with old horseshoe 
nails (called stubs) set perpendicularly, till it can hold no 
j more : a pointed bar of iron is then driven into the cen- 
tre of the circle, and thus locks the whole fast together* 
A welding heat is then applied, and the mass is ham- 
I meredvery gently at first, till the nails and ring become 
compleatly united : it is then drawn down into bars and 
I affords an iron of peculiar closeness, toughness, and mal- 
! leability.” — Aikin. 
“To produce malleable iron in its pure state, many and 
various have been the processes adopted : these however 
have all in some measure fallen short. Malleable iron 
ought to possess no foreign mixture whatever, to be in a 
state of purity ; but as the modes of operation have hither- 
to consisted in manufacturing this state of the metal from 
crude iron, and as crude iron is always found to contain 
principles inimical to malleability, it is obvious, that the 
quality of malleable iron will at all times depend upon 
$fee degree of expulsion of the alterative mixtures contain* 
