between the Monitor and Merrimac had proved to be a success. Mr. Eads was allowed, however, to modify the Ericsson turret considerably, in order to avoid making the draft of his steamers greater than was desired. He built the "Osage" and "Neosho," and when these vessels were launched, with all their weight on board, it was found that they were really lighter than the contract called for, a circumstance which permitted the thickness of their armor to be afterward increased half an inch without injuring their draught or speed.
In May, 1862, at the request of the Navy Department, Mr. Eads submitted plans for four iron-clads, iron hull propellers, to carry two turrets each of eight inches thickness, four eleven inch guns, and three-quarters inch deck armor, to steam nine nautical miles per hour, to carry three days' coal, and not to exceed a draught of six feet of water. His plans were accepted, and he constructed the "Winnebago," "Kickapoo," "Milwaukee," and "Chickasaw." Like the "Osage" and "Neosho," these vessels were found to be of lighter draught than had been agreed upon, and the Department ordered all four to have an extra plating of three-quarters inch armor, which was done. Three of the vessels were also reported, by the officers of the navy sent to examine them, to exceed the speed required by the contract, while the fourth was fully up to the standard.