columbiads have longer trunnions that were intended for use with heavy wooden carriages. The Union gun were designed to be mounted in iron carriages with thinner cheeks, permitting shorter trunnions. The exteriors of the Confederate columbiads are rough, not having been finished on a lathe as were their Union counterparts. On November 14, 1864, and February 20, 1865, Anderson cast two 12-inch columbiads using the Rodman method at the Tredegar Iron Works. The guns were made too late and were never finished or mounted. Similar weapons The 3-inch ordnance rifle and the 4.5-inch siege rifle were frequently misidentified as Rodmans. Neither gun was hollow cast. The 3-inch ordnance rifle was made of hammer-welded wrought iron, and the 4.5-inch siege rifle was conventionally cast. This error was not limited to those ignorant of artillery; in November 1864 Brig. Gen. John Milton Brannan, chief of artillery in the Union Department of the Cumberland, described the armament of the Chattanooga forts as including several 3-inch and 4.5-inch Rodman guns. First Lieutenant Henry S. Hurter of the 1st Minnesota Light Artillery Battery wrote in his report to Oscar Malmros, Adjutant General for the State of Minnesota, "On the 5th of March captain Clayton exchanged the old guns, two 12-pound howitzers, and two 6-pound rifled guns, caliber 3.67, for four new rifled 3-inch Rodman's guns." The letter was written on November 11, 1864, in Georgia. Gallery See also Parrott rifle Siege artillery in the American Civil War Seacoast defense in the United States Notes References External links The Civil War Artillery Page Civil War Artillery Projectiles Civil War Field Fortifications Website The World's Fair and Exposition Information and Reference Guide: 1876 US Centennial Exhibition Coastal artillery American Civil War artillery Cannon