We learn from our foreign exchanges that experimental firing has recently been conducted at Portsmouth with Captain Cole’s cupola vessel, having two 100 pounders placed in a tower and firing at a target. The two 100-pounders were fired singly and together and in quick firing six rounds were fired in as many minutes. The concussion from the discharge of the guns was but trifling, and was, in fact found to be greater outside the shield than within it. The smoke cleared off as effectually and the guns, with their carriages, worked with the greatest facility. The shield ship which is proposed to build on this plan will have no masts, and when afloat will show to the view above her deck merely her funnel and the tops of her shields. Cleared for action, the ship’s bulwarks are thrown down all around here, level with the upper deck, along the center of which are ranged her cupola shields, resembling gigantic inverted teasaucers, each containing two 100-pounder Armstrongs of 88 cwt. These shields rest upon towers, which are sunk through the upper deck, and are fixed on a turntable on the deck below, which revolves with the guns, shields and men, as may be required. The hight [sic] of the shield from the upper deck will be about five feet, which will be but a small object for an enemy to fire at; shot can only strike it at an angle of 45 deg. The muzzle of the guns will be 9 feet 6 inches from the water. The sides of the vessel will be covered with armor plating. The shield ship will be 2,500 tuns measurement, and her estimated cost is, as far as can be ascertained at present, $900,000. Her draught of water is to be 20 feet, and her speed 12½ knots.
– Published in the Burlington Weekly Hawk-Eye, Burlington, Iowa, Saturday, April 12, 1862, p. 2