...iest guns used at this time were 18-pounders. William Denning makes wrought-iron cannon of staves bound together with wrought-iron bands, and boxed and breeched, 1790. Colonel Bomford, of the United States ordnance department, invents a cannon called the columbiad, a long-chambered piece for projecting solid shot and shell with a heavy charge of powder, 1812. West Point foundry established under sp...