Popular Science Monthly/Volume 2/April 1873/Sketch of Professor Henry



PROF. JOSEPH HENRY, who is widely known throughout the scientific world for his various original investigations, and as the organizer and Permanent Secretary of the Smithsonian Institution, is of Scotch descent, and was born in Albany, in the State of New York. Having lost his father in early childhood, he was sent at the age of seven years to live with his grandmother, and to attend school at Galway, in Saratoga County, where he remained until he was fourteen. Having accidentally and secretly obtained access to the village library, he became fascinated with books of fiction, and devoted much of his time to reading. Returning to Albany, he was apprenticed to the trade of a jeweller, with which he was occupied two years. He afterward developed a passion for serious study, and became teacher of a country district school. He studied for a time in the Albany Academy, and, through the recommendation of its principal, Dr. T. Romeyn Beck, was appointed private tutor in the family of General Stephen Van Rensselaer, the patroon of Rensselaerwyck. There his duties occupied him three hours a day, and the rest of his time was spent as an assistant to Dr. Beck, in his chemical investigations; but he also studied anatomy and physiology, with a view to graduating in medicine. He, however, obtained a position as an engineer to survey a route for a State road from the Hudson River to Lake Erie, through the southern tier of counties. Having finished this arduous and responsible labor, he was elected to fill the vacant chair of Mathematics in the Albany Academy. As the duties did not begin immediately, he spent several months exploring the geology of New York State with Prof. Eaton, of the Rensselaer Institute of Troy. He entered upon his work at the academy in 1826, and then commenced a course of 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.

Prof. Henry was married in May, 1830, to Miss Alexander, of Schenectady, the sister of Prof. Alexander, of Princeton, and from the ardent devotion of his wife, and the fraternal sympathy of her brother in his pursuits, he has received assistance and support beyond that which usually fall to the lot of men. The most peaceful, and to himself the most profitable, part of his life was that spent in Princeton, for which place, and the college connected with it, he retains the warmest attachment.

The following is a brief enumeration of his scientific investigations and discoveries:

1. A sketch of the topography of the State of New York, embodying the results of the survey before mentioned.

2. In connection with Dr. Beck and the Hon. Simeon De Witt, the organization of the meteorological system of the State of New York.

3. The development, for the first time, of magnetic power, sufficient to sustain tons in weight, in soft iron, by a comparatively feeble galvanic current.

4. The first application of electro-magnetism as a power, to produce continued motion in a machine.

5. An exposition of the method by which electro-magnetism might be employed in transmitting power to a distance, and the demonstration of the practicability of an electro-magnetic telegraph, which, without these discoveries, was impossible.

6. The discovery of the induction of an electrical current in a long wire upon itself, or the means of increasing the intensity of a current by the use of a spiral conductor.

7. The method of inducing a current of quantity from one of intensity, and vice versa.

8. The discovery of currents of induction of different orders, and of the neutralization of the induction by the interposition of plates of metal.

The discovery that the discharge of a Leyden jar consists of a series of oscillations backward and forward until equilibrium is restored.

10. The induction of a current of electricity from lightning at a great distance, and proof that the discharge from a thunder-cloud also consists of a series of oscillations.

11. The oscillating condition of a lightning-rod while transmitting a discharge of electricity from the clouds causing it, though in perfect connection with the earth, to emit sparks of sufficient intensity to ignite combustible substances.

12. Investigations on molecular attraction, as exhibited in liquids, and in yielding and rigid solids, and an exposition of the theory of soap-bubbles. (These originated from his being called upon to investigate the causes of the bursting of the great gun on the United States steamer Princeton.)

13. Original experiments on, and exposition of, the principles of acoustics, as applied to churches and other public buildings.

14. Experiments on various instruments to be used as fog-signals.

15. A series of experiments on various illuminating materials for light-house use, and the introduction of lard-oil for lighting the coasts of the United States. This and the preceding in his office of chairman of the Committee on Experiments of the Light-House Board.

16. Experiments on heat, in which the radiation from clouds and animals in distant fields was indicated by the thermo-electrical apparatus applied to a reflecting telescope.

17. Observations on the comparative temperature of the sun-spots, and also of different portions of the sun's disk. In these experiments he was assisted by Prof. Alexander.

18. Proof that the radiant heat from a feebly luminous flame is also feeble, and that the increase of radiant light, by the introduction of a solid substance into the flame of the compound blow-pipe, is accompanied with an equivalent radiation of heat, and also that the increase of light, and radiant heat in a flame of hydrogen, by the introduction of a solid substance, is attended with a diminution in the heating power of the flame itself.

19. The reflection of heat from concave mirrors of ice, and its application to the source of the heat derived from the moon.

20. Observations, in connection with Prof. Alexander, on the red flames on the border of the sun, as observed in the annular eclipse of 1838.

21. Experiments on the phosphorogenic ray of the sun, from which it is shown that this emanation is polarizable and refrangible, according to the same laws which govern light.

22. On the penetration of the more fusible metals into those less readily melted, while in a solid state.

Besides these experimental additions to physical science, Prof. Henry is the author of twenty-five (1846-'71) reports, giving an exposition of the annual operations of the Smithsonian Institution. He has also published a series of essays on meteorology in the Patent-Office Reports, which, besides an exposition of established principles, contain many new suggestions; and, among others, the origin of the development of electricity, as exhibited in the thunderstorm; and an essay on the principal source of the power which does the work of developing the plant in the bud, and the animal in the egg.

He has also published a theory of elementary education, in his address as President of the American Association for the Advancement of Education, the principle of which is, that in instruction the order of Nature should be followed; that we should begin with the concrete and end with the abstract, the one gradually shading into the other; also the importance of early impressions, and the tendency in old age to relapse into the vices of early youth.