original investigations on electricity and magnetism, the first regular series on Natural Philosophy which had been prosecuted in this country since the days of Franklin. These researches made him favorably known not only in this country, but in Europe, and led to his call in 1832 to the chair of Natural Philosophy in the College of New Jersey at Princeton.
In the first year of his course in this institution, during the absence of the Professor of Chemistry, Dr. Torrey, in Europe, he gave lectures in Natural Philosophy, Chemistry, Mineralogy, Geology, Astronomy, and Architecture. This work interrupted his original investigations, but he soon commenced anew where he had left off at Albany, and devoted himself to a work of research, until he was called to his present position in Washington. In 1835 he was granted by the trustees of the college a year's absence in Europe, nine months of which he spent principally in Paris, London, and Edinburgh, in intercourse with the savants of these cities, and procuring more efficient apparatus to prosecute his investigations.
Meantime Mr. John Smithson, of England had left a large sum of money to the Government of the United States, to be devoted "to the increase and diffusion of knowledge among men." An institution was projected to carry out this purpose, and in 1846 Prof. Henry was requested by some of the members of the Board of Regents to give his views as to the best methods of realizing the intentions of its founder. In compliance with this request he gave an exposition of the will, and of the method by which it might most efficiently be realized. On account of this exposition and his scientific reputation, he was called to the office of Secretary or Director of the establishment. Unfortunately, Congress had attempted to organize the institution without a due appreciation of the terms of the will. This gave rise to difficulties and expenditures on local objects, particularly to the commencement of a very expensive building, which have much retarded the full realization of what might have been produced by the plan originally proposed by Prof. Henry.
At the time of the organization of the Light-House Board of the United States, Prof. Henry was appointed by President Fillmore one of its members, and he still continues in the position. During the war he was appointed one of a commission, together with Prof. Bache and Admiral Davis, to examine and report upon various inventions, intended to facilitate the operations against the enemy, and to improve the art of navigation. On the death of Prof. Bache, he was elected President of the National Academy of Sciences, established by an act of Congress in 1863, to advance science, and to report upon such questions of a scientific character as might be connected with the operations of the Government. He is a member of various societies in this country and abroad, and has several times received the degree of LL.D., the last time from Cambridge, Massachusetts.