The result of the battle between the "Monitor" and the "Merrimac" in Hampton Roads is a part of history. The relentless devastation which the latter had begun on the old wooden ships of the American Navy at Hampton Roads was stayed, and the wild fears at the North concerning the destruction which she might cause to the shipping and to the seaboard cities was calmed. The "Merrimac" met her master, and retired from the conflict crippled and shorn of power for further evil. A short time later she sank beneath the waters of the Chesapeake, and is now remembered only as the antagonist of the "Monitor."
If the result of this battle between the "Monitor" and the "Merrimac" marked a turning-point in the naval aspect of the Civil War, it wrought a no less marked change in the standing and fortunes of her designer. Some of his engineering efforts had not met with the success for which he or his friends had hoped. The engines of the air-ship, while a success as a piece of mechanism, were so enormous and heavy that she had to be considered as a commercial failure, and the venture was not repeated; the deplorable accident on the "Princeton" was by some held to be in part chargeable to Ericsson, though a later and full knowledge of the circumstances shows that such was in no wise the case. Again, Ericsson, as an experimenter and pioneer, was by some considered as a dreamer, and before the "Monitor" was completed there was no lack of croakers who prophesied failure or who openly ridiculed the idea. This condition was of course natural. In many ways Ericsson was ahead of his age; and, again, it must not be supposed that he avoided mistakes or that all of his work fully realized the expectations which were based upon it. Furthermore, Ericsson's spirit was proud, and he was little disposed to accept criticism from those whom he felt to be unqualified to pass adequate judgment on his work, while he was especially impatient under the system by which government work was done. He was therefore but little disposed to pleasantly submit to the exasperating delays and interferences with his work which arose from the methods of doing public business, and it is no more than the simple truth to say that during the preceding years the relations between Ericsson and the officials of the Navy Department had often become seriously strained, and they were seldom in cordial accord regarding the various questions which arose in connection with his public work.
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.
This prodigious load was not so much but that he found time to devote to the needs of other nations, and in 1862 he offered to construct for the Chilian government a monitor similar to those under construction for the United States, while later a similar offer was made to the Peruvian Government. With the close of the Civil War Ericsson found still further time to devote to the introduction of this type of vessel into foreign navies, and a considerable part of his time seems to have been occupied with projects of this character, and more particularly with the question of the naval defence of his native land. As regards the introduction of warships of the monitor type, the results were not so pronounced as might have been expected, and while the influence of the idea is seen in the practice of every maritime nation in regard to the construction of its warships, still, for the most part, the leading nations preferred to make application of the idea in their own way rather than order such vessels direct from their original designer. Yet in not a few cases the original type was faithfully copied, though it is not always clear to what extent Ericsson himself may have had direct contact with their designs. In 1866 the Swedes were able to test the first of a small fleet of monitors built after Ericsson's plans. This was called the "John Ericsson," and was armed with two 15-inch guns presented to Sweden by Ericsson himself. Later, in 1868, he designed for Spain and superintended the construction of thirty small gunboats for use in Cuban waters.
For nearly ten years now Ericsson had devoted most of his energies to the art of war. It was a time of change and unrest. Heavy guns and armor had brought about a complete break with the past. The torpedo, which had made its appearance in crude form during the Civil War, was attracting more and more attention, and questions of naval offence and defence and of the best governmental policy were attracting the serious attention of all whose duty led them into relation with such matters. Into this problem in its broadest aspects Ericsson threw himself in the early 'seventies with all the ardor of his younger days.
It is proper to explain here that there was one feature of the earlier plans which were submitted to Napoleon III. in 1854, which he did not embody in the "Monitor," and which, indeed, was omitted from all published plans and descriptions of the system given out in former years. This was a system of submarine or subaqueous attack, which, he states in a letter to John Bourne, had attracted his attention since 1826. The time now seemed ripe for the presentation and development of this idea, and he accordingly developed his designs for a torpedo, and for a method of firing it under water from a gun carried in the bow of a boat, and suitably opening to allow the discharge of the torpedo projectile. This was Ericsson's so-called "Destroyer" system, and was embodied finally in a boat called the "Destroyer," which he built in company with his friend, Mr. C.H. Delamater, and with which he carried on numerous experiments. In the end, however, the system did not commend itself to the naval authorities, and the "Destroyer" was left on her designer's hands, an instance of difference of opinion between Ericsson and those charged with the duty of naval administration, and with no supreme test of war to provide opportunity for the determination as to which were the more correct in their judgment. With the "Destroyer," and his work in connection with her, closes the record of Ericsson's connection with the advance in naval construction.
During these later years of his life it must not be supposed that he was less busily occupied than in earlier life. His was a nature which knew no rest, and to the last day of his life he was literally in the harness. Only brief mention however can be made of some of the more important lines of work which interested the closing years of Ericsson's life.
In connection with his naval designs, he devoted much study to the improvement of heavy ordnance, both as to the gun and its mounting. In particular, his mounting of the guns in the "Monitor" was quite original, and the friction arrangement for absorbing the recoil was a great improvement over methods then in use, and served as a model for many copies and adaptations of the same principles in later years by other designers. In 1863 he also designed and built for the acceptance of the Government a forged 13-inch wrought-iron gun. While his design was an advance on those of the day, the demands on the makers of iron forgings were more than could be successfully met, and the gun developed some slight cracks in the test, which prevented further developments on this line. Ericsson always maintained that the tests to which this gun was submitted were unfairly severe, and he showed how the defects could be remedied by a steel lining. But the Naval Bureau of Ordnance insisted that this should be done at his own expense, and as he had already lost some $20,000 on the gun, he was unwilling to proceed farther, and the matter was allowed to lapse.
Throughout his entire career the improvement of the steam-engine occupied a large share of Ericsson's attention, and in particular was this the case in connection with his naval designs. From the "Princeton," in 1841, to the "Destroyer," in 1878, there succeeded one long series of types and forms of steam-engine, each in his opinion the best adapted to the circumstances of the case. Naturally, opinions differ, and he was brought into competition with other able engineers, and his designs were often called into question or subjected to criticism. In 1863, in competition with Chief Engineer Isherwood of the navy, engines were designed for twin ships, the "Madawaska," afterward known as the "Tennessee," and the "Wampanoag," afterward called the "Florida." This was a battle royal of types and modes of application of the power of the steam-engine to the propulsion of ships. The result was a victory for Isherwood, although the "Madawaska," which was first subjected to trial, made a speed higher than any warship at that time afloat. This was exceeded by the "Wampanoag" a short time later; but neither engine was of an enduring type, and after a time the machinery of the "Madawaska" was removed, and she was repowered with a later type of machinery, and long did service as the "Tennessee" in the list of wooden frigates of the navy. The "Florida" was too expensive to maintain in commission, and the special circumstances which had called her into existence having passed by, she was laid up at New London, and never again saw active service.