Before revision: Background One of the earliest, if not the earliest built-up gun was a 12-inch smoothbore muzzleloader designed by John Ericsson and produced by Mersey Iron Works in Liverpool for the ca.
After revision: Background The first built-up gun was designed by French artillery officer Alfred Thiéry in 1834 and tested not later than 1840; about the same time another one was made by Daniel Treadwell, and yet another one was produced by Mersey Iron Works in Liverpool for the ca.