Thomas Wilhelm, A Military Dictionary and Gazetteer
“ The 30-pounder Parrott, so extensively employed in our service for siege purposes, is not a regulation gun. The sea-coast guns consist of 13-, 15-, and 20-inch smooth-bores, and 10- and 12-inch rifles. An 8-inch rifle has been constructed by converting the 10-inch smooth-bore according to the Palliser or Parsons method. The 13-inch smooth-bore and the 10- and 12-inch rifles are regarded as experimental guns. The guns principally in use for the land and sea forces of the United States are those known as the Columbiad, or Rodman, Dahlgren, Gatling, Hotchkiss, Napoleon, Parrott. ”
