Returning again to our note of the dependence of the present age on Ericsson, mention may be made of the blower for forcing the combustion in steam-boilers as a well-established feature of standard marine practice, and one absolutely essential to the development of the highest attainable speeds, such as are required in warships, and especially in those of the torpedo and modern "Destroyer" types. Likewise the use of the fan for ventilation, as used by him in his early practice, has become a necessity of modern conditions both on naval and passenger ships, for the health and comfort of both passengers and crew. His long series of experiments and his years of labor on air and other forms of "caloric" engine are only represented by the "Ericsson air-engine" now on the market, and having its fair share of service in locations where simplicity of operation and scarcity of water may naturally suggest its use.
Of his labors in connection with a solar engine, and with other questions which occupied much of the time of his closing years, we have but little direct result. Others are at work on the idea of the solar engine, and it may be that a practicable solution of the problem will be found.
Ericsson's lasting imprint on engineering practice, curious as it may seem, was made in his earlier and middle life, rather than in his later years, and we have even more in the way of permanent acquisition from his earlier than from his middle years. This results from the fact that in middle life he was largely engaged on warship designs, admirably adapted to the needs of the time and to the possibilities of the age, but no longer suited to either, while in later life he no longer found it necessary to work at problems which would produce a direct financial return, and therefore interested himself in a variety of questions somewhat farther removed from the walks of every-day engineering practice than those with which he was occupied in earlier life.
In personality Ericsson possessed the most pronounced and self-centred characteristics. Professionally he felt that to him had been granted a larger measure of insight than to others into the mysteries of nature as expressed in the laws of mechanics, and he was therefore little disposed to listen to the advice or criticism of those about him. This was undoubtedly one of Ericsson's most pronounced professional faults. He did not realize that with all his insight into the laws of mechanics and all his capacity for applying these laws to the solution of the problems under consideration, he might well make some use of the work of his fellow-laborers in the same field. So little disposed was he to thus use the work of others that a given device or idea which had been in previous use was often rejected and search made for another, different and original, even though it might involve only some relatively trivial part of the work. He was simply unwilling to follow in the lead of others. He must lead or have none of it, and thus the fact that a device or expedient was in common use would furnish an argument against rather than for its adoption. His natural mode of work was utterly to disregard precedent and to seek for fundamental solutions of his problems, having only in view the conditions to be fulfilled, the laws of mechanics, and the engineering materials of construction. This habit of independence and of seclusion within the narrow circle of his own work so grew upon him in later years that mechanical science made many advances of which he took little or no note, and of which he refused to avail himself, even though he might have done so greatly to his own advantage.
In his later years, in a letter to his friend Captain Adlersparre, he says: "Do not laugh at me now, Captain, when I say that nobody can mislead me. Do not condemn me if I at the same time confess that I am directed by nobody's judgment but my own, and that I never consult anybody and take nobody's advice." In all matters connected with his work his will was imperious, and he would brook no interference or criticism. His temper was high, his organization sensitive, and many times throughout his life, relations with his best friends became strained by his instability of temper or impatience with what he might construe as a criticism regarding his work. With this instability of temper, however, was combined a deep-seated tenderness and kindness of heart, and he was as quick to forget the cause of offence as he was to manifest displeasure upon occasion.
Notwithstanding the asperities of Ericsson's character in regard to his professional work, and his entire lack of effort to make friends among the learned of his day, recognition and unsought honors came in upon him. He was elected to honorary membership in the societies of note in the United States and Sweden, and in addition to the thanks of Congress and of the Legislature of the State of New York, he received a resolution of thanks from the Swedish Riksdag, or Parliament, in 1865. In 1862 he was granted the rarely bestowed Rumford medal, and received at other times during his life medals, honors, and decorations such as have perhaps fallen to no other who has wrought in the same field of human effort. While recognition of this character pleased him greatly when it came spontaneously and willingly, he placed but little value on that which he thought grudgingly or tardily tendered, and in one or two instances refused membership in societies which he thought granted in that manner.
A large measure of this independence of character is necessary to the performance of the work which Ericsson did. Had he been ever ready to listen to the views of others, and to modify his ideas in accordance with them, his greatest achievements would never have been accomplished. In Ericsson, however, this characteristic was carried to an undue extreme, and he might unquestionably have accomplished more had he been able to co-operate with others and to accept and use freely the best work of contemporaries in his own field.
Ericsson was essentially a designing rather than a constructing engineer. His genius lay in new adaptations of the principles of mechanics or in new combinations of the elements of engineering practice in such way as to further the purposes in view. His mode of expression was the drawing-board. While he wrote vigorously and well, and while he was a frequent contributor in later years to scientific literature, especially on the subject of solar physics, yet his best and natural mode of expression was the graphical representation of his designs on the drawing-board. Forms and combinations took shape in his brain and were transferred to the drawing with marvellous speed and skill. Those who have been associated with him bear testimony that the amount of his work was simply astounding, and that only by a combination of the most remarkable celerity and industry could they have been accomplished.
These drawings were furthermore so minute in detail and so accurate in dimension that as a rule he did not find it necessary to give further attention to the matter after it had left his hands. Of the many parts of a complicated mechanism, one could be sent for construction to one shop and another elsewhere, all ultimately coming together and making a harmonious and perfectly fitting whole. In no other way could such astonishing speed in the detailed construction of the "Monitor" and other vessels of her type possibly have been made; and the fact that such speed in construction was obtained, and largely in this manner, is by no means the least impressive of the many evidences of Ericsson's genius as a designer.
The designs once completed on the drawing-board, however, Ericsson's interest in the work ceased in great measure, and as a rule he paid but little attention to constructive details, and took but slight interest in the completed whole. Thus he is said to have visited his "Destroyer" but once after she was built, and then simply in search of his assistant. He also declined an invitation from the Assistant Secretary of the Navy to visit Hampton Roads and inspect the "Monitor" immediately after her fight with the "Merrimac." He seemed to have no curiosity to inspect his work after it had left his hands, or to receive a report as to the practical working of his designs. This shows a peculiar lack of appreciation of the value of intimate contact with constructive and operative engineering work. No one could hope to avoid errors, or to realize by drawing-board alone the best possible solution of engineering problems. Ericsson wilfully handicapped himself in this manner, and might unquestionably have more effectively improved and perfected his ideas had he been disposed to combine with his designs at the drawing-board practical contact with his work as constructed.