Note 9 — Chapter IV · ON THE MANUFACTURE OF IRON FOR GUN BARRELS.

Iron, semi-steelified, is made with charcoal 1-150th part.

Soft cast steel, capable of welding with ditto 1-120th do.

Cast steel, for common purposes, with ditto 1-120th do.

Cast steel, requiring more hardness, with charcoal 1-90th do.

Steel, capable of standing a few blows, but quite unfit for drawing with ditto 1-150th do.

First approach to a steely granulated fracture is from 1-50th to 1-40th do.

White cast iron, with charcoal 1-25th do.

Mottled cast iron, with ditto 1-20th do.

Carbonated cast iron 1-15th do.

And supercarbonated crude iron 1-12th do.