With the demonstration made by the "Monitor," however, the attitude of the public changed in a moment, and Ericsson was hailed on every hand as a public benefactor. He received the thanks of Congress on March 28, 1862, and of the Legislature of the State of New York a little later. Besides these, he was the recipient of numbers of memorials and mementoes, and of such praise in every form as might well have disturbed the equilibrium of a mind less well balanced. In all this change of public opinion, the one thing which must have given him the deepest satisfaction was the change in the attitude of the naval authorities at Washington. He was now considered as one whose ideas had demonstrated their right to serious and respectful attention, and a large fleet of vessels of the monitor type was ordered, similar to but larger than the prototype, and containing such minor changes as experience had suggested. Yet even this was not accomplished without objection. The officers of the navy were accustomed to the old type of wooden ship, and were slow to realize that naval war was, after all, an engineering problem, and that the ideas of the engineer must now be substituted for those which had been sanctified by long ages of past experience. Still, the demonstration was too convincing to admit of serious question, and Ericsson and his associates in business were busily occupied during the remainder of the war in the design and construction of a numerous fleet of vessels of the monitor type. Ericsson's work during this period was enormous. One design followed another in quick succession, while work of supervision and inspection and cares of a business nature all combined to make a burden which would have broken down a nature less determined and self-centred, and a body less inured to physical endurance and sustained nervous tension.