In 1832, Princeton College needed a professor of natural philosophy.
Henry"s friends heartily commended him for the position. Silliman said,--"Henry has no superior among the scientific men of the country,"
and Professor Renwick of Columbia College, New York, said, "He has no equal."
After six years at the Albany Academy, Henry removed to Princeton, where for fourteen years he added constantly to his fame and usefulness by original work. Of his discoveries in these fruitful years he gives the following summary, at the request of a friend:--
"I arrived in Princeton in November, 1832, and, as soon as I became fully settled in the chair which I occupied, I recommenced my investigations, constructed a still more powerful electro-magnet than I had made before,--one which would sustain over three thousand pounds,--and with it ill.u.s.trated to my cla.s.s the manner in which a large amount of power might, by means of a relay magnet, be called into operation at the distance of many miles.... The electro-magnetic telegraph was first invented by me, in Albany, in 1830.... At the time of making my original experiments on electro-magnetism in Albany, I was urged by a friend to take out a patent, both for its application to machinery and to the telegraph; but this I declined, on the ground that I did not then consider it compatible with the dignity of science to confine the benefits which might be derived from it to the exclusive use of any individual. In this perhaps I was too fastidious."
Professor Asa Gray well said, "For the telegraph and for electro-magnetic machines, what was now wanted was not discovery, but invention; not the ascertainment of principles, but the devising of methods." Morse is not to be less honored because somebody discovered the principle, which he and others utilized for the race, any more than Edison, Bell, and others, because Faraday and Henry helped to make their grand work possible.
"My next investigation, after being settled at Princeton," says Professor Henry, "was in relation to electro-dynamic induction. Mr.
Faraday had discovered that when a current of galvanic electricity was pa.s.sed through a wire from a battery, a current in an opposite direction was induced in a wire arranged parallel to this conductor. I discovered that an induction of a similar kind took place in the primary conducting wire itself, so that a current which, in its pa.s.sage through a short wire conductor, would neither produce sparks nor shocks would, if the wire were sufficiently long, produce both those phenomena....
"A series of investigations was afterwards made, resulting in producing inductive currents of different orders, having different directions, made up of waves alternately in opposite directions....
"Another series of investigations, of a parallel character, was made in regard to ordinary or frictional electricity. In the course of these it was shown that electro-dynamic inductive action of ordinary electricity was of a peculiar character, and that effects could be produced by it at a remarkable distance. For example, if a shock were sent through a wire on the outside of a building, electrical effects could be exhibited in a parallel wire within the building."...
After this, investigations were made in atmospheric induction; induction from thunder clouds; in regard to lightning rods; on substances capable of exhibiting phosph.o.r.escence, such as the diamond, which, when exposed to the direct rays of the sun, and then removed to a dark place, emits a pale blue light; on a method of determining the velocity of projectiles; on the heat of the spots on the sun as compared with the rest of his disk; the detection of heat by the thermal telescope--"when the object was a horse in a distant field, the radiant heat from the animal was distinctly perceptible at a distance of at least several hundred yards;"
on the cohesion of liquids; on the tenacity of soapwater in films; on the origin of mechanical power, and the nature of vital force.
Henry says:--
"The mechanical power exerted by animals is due to the pa.s.sage of organized matter in the stomach, from an unstable to a stable equilibrium; or, as it were, from the combustion of the food. It therefore follows that animal power is referable to the same source as that from the combustion of fuel--namely, developed power of the sun"s beams. But, according to this view, what is vitality? It is that mysterious principle--not mechanical power--which determines the form and arranges the atoms of organized matter, employing for this purpose the power which is derived from the food....
"Suppose a vegetable organism impregnated with a germ (a potato, for instance) is planted below the surface of the ground, in damp soil, under a temperature sufficient for vegetation. If we examine it from time to time, we find it sending down rootlets into the earth, and stems and leaves upward into the air. After the leaves have been fully expanded we shall find the tuber entirely exhausted, nothing but a skin remaining. The same effect will take place if the potato be placed in a warm cellar; it will continue to grow until all the starch and gluten are exhausted, when it will cease to increase. If, however, we now place it in the light, it will commence to grow again, and increase in size and weight. If we weigh the potato previous to the experiment, and the plant after it has ceased to grow in the dark, we shall find that the weight of the latter is a little more than half of the original tuber.
The question then is, what has become of the material which filled the sac of the potato? The answer is, one part has run down into carbonic acid and water, and in this running down has evolved the power to build up the other part into the new plant. After the leaves have been formed and the plant exposed to the light of the sun, the developed power of its rays decomposes the carbonic acid of the atmosphere, and thus furnishes the pabulum and the power necessary to the further development of the organization.
"The same is the case with wheat, and all other grains that are germinated in the earth. Besides the germ of the future plant, there is stored away, around the germ, the starch and gluten to furnish the power necessary to its development, and also the food to build it up, until it reaches the surface of the earth and can draw the sources of its future growth from the power of the sunbeam. In the case of fungi and other plants that grow in the dark, they derive the power and the pabulum from surrounding vegetable matter in process of decay, or in that of evolving power."...
"What then is the office of vitality? We say that it is a.n.a.logous to that of the engineer who directs the power of the steam-engine in the execution of its work."
"If he had published in 1844, with some fulness, as he then wrought them out," says Professor Gray, "his conception and his attractive ill.u.s.trations of the sources, transformation, and equivalence of mechanical power, and given them fitting publicity, Henry"s name would have been prominent among the pioneers and founders of the modern doctrine of the conservation of energy."
Henry always defined science as the "knowledge of natural law," and law as the "will of G.o.d." He found all things, even the storms, under the "control of laws--fixed, immutable, and eternal," and rejoiced in believing that "a Supreme Intelligence who knows no change" governs all.
For him there was never any conflict between science and religion.
In February, 1837, Henry went to Europe, accompanied by Prof. Alexander D. Bache, at the head of the United States Coast Survey for eighteen years. He became the friend of Faraday; of Wheatstone, then Professor of Experimental Philosophy in King"s College, who was engaged in developing his system of the needle telegraph; of Arago, Gay-Lussac, and other noted men. "At King"s College," says Prof. Alfred M. Mayer, "Faraday, Wheatstone, Daniell, and Henry had met to try and evolve the electric spark from the thermopile. Each in turn attempted it and failed. Then came Henry"s turn. He succeeded, calling in the aid of his discovery of the effect of a long interpolar wire wrapped around a piece of soft iron. Faraday became as wild as a boy, and, jumping up, shouted: "Hurrah for the Yankee experiment!"" "It is not generally known or appreciated," says Professor Mayer, "that Henry and Faraday independently discovered the means of producing the electric current and the electric spark from a magnet.... Henry cannot be placed on record as the _first_ discoverer of the magneto-electric current, but it _can_ be claimed that he stands alone as its _second_ independent discoverer."
Both James D. Forbes of Edinburgh and Henry obtained the spark, but were antic.i.p.ated by Faraday.
Henry spoke before the various scientific societies. He was no longer the apprentice to a watch-maker, or the leader of private theatricals, but a distinguished scholar. By his own will and energy he had attained to this enviable position.
Meantime a man of science, in England, had thought out a great project for the benefit of his fellow-men. James Smithson, a wealthy English chemist, a Fellow of the Royal Society, unmarried, died in 1829. He left his property, over five hundred and forty thousand dollars, after the death of his nephew, provided that he died childless, "to the United States of America, to found at Washington, under the name of the Smithsonian Inst.i.tution, an establishment for the increase and diffusion of knowledge among men." The nephew died six years later, unmarried.
This was indeed a wonderful gift,--and from a stranger! Difficulties at once presented themselves. How could the property be used "for the increase and diffusion of knowledge among men"? "For ten years," says Garfield, "Congress wrestled with those nine words of Smithson, and could not handle them. Some political philosophers of that period held that we had no const.i.tutional authority to accept the gift at all, and proposed to send it back to England. Every conceivable proposition was made."
John Quincy Adams desired a great astronomical observatory. One person wished an agricultural school; another, a college for women; another, that the funds should be devoted to meteorological observations all over the Union. Finally, a board of regents was appointed, with power to choose a suitable person as secretary.
He must be a learned man, a wise financier, with good judgment and pleasant manners. Professor Henry fulfilled all the conditions. He was admired for his learning; in finance he was wise, as thirty years have proved, the inst.i.tute with its endowment now being valued at one and a half million dollars; his kindly manner made him accessible, willing to listen to any one who hoped or believed he had discovered something in the line of knowledge. A man who can be harsh or cold to an ignorant person, or indeed to anybody, does not deserve to hold any public position. With natural quickness of temper in early life, he had gained remarkable self-control. Like Baron Cuvier, he had no tolerance for sarcasm or "practical jokes." Henry was unanimously chosen, entering upon his duties December 3, 1846. He had a definite plan of the work which ought to be done, and "after due deliberation it received the almost unanimous approval of the scientific world."
He believed that the money should be used in original scientific work; by helping men to publish the results of such work; to aid in varied explorations; to send scientific publications all over the world. The inst.i.tution is now the princ.i.p.al agent of scientific and literary communication between the old world and the new. The number of foreign inst.i.tutions and correspondents receiving the Smithsonian publications exceeds two thousand, scattered from New Zealand and India to Yokohama, in j.a.pan, and Cape Town, in Southern Africa. The weight of matter sent abroad for ten years, ending 1877, was ninety-nine thousand pounds.
Among the first subjects taken up by the inst.i.tution for investigation was that of American archaeology, an attempt to ascertain the industrial, social, and intellectual character of the earliest races on our continent. The first publication of "Smithsonian Contributions" was a work on the mounds and earthworks found in the Mississippi valley, a most fascinating study.
The Smithsonian, "first in the world, organized a comprehensive system of telegraphic meteorology, and has thus given first to Europe and Asia, and now to the United States, that most beneficent national application of modern science--the storm warnings."
So much of value has been gathered by government surveys and by voluntary contribution that the inst.i.tution has sent duplicates to various societies of specimens in geology, mineralogy, botany, zoology, and archaeology, while it has remaining, "boxed up, varieties of art and nature" more than enough to twice fill the halls and galleries of the building.
The work of Professor Henry grew more and more onerous, but he seemed to leave nothing undone. For many years he served gratuitously as chairman of the Lighthouse Board. When a subst.i.tute was needed for sperm oil, after almost numberless experiments, he showed that lard oil is the best illuminant, thereby saving the country over one hundred thousand dollars yearly, since 1865.
During the last twelve years of his life, he devoted much time to our system of coast fog-signals, making "contributions to the science of acoustics, unquestionably the most important of the century."
Observations were made, among other places, at Block Island and Point Judith. The distance between these fog-horns is seventeen miles, and the sound of one can be distinctly heard at the other when the air is quiet and h.o.m.ogeneous; but if the wind blows from one towards the other, the listener at the station from which the wind blows is unable to hear the other horn.
While at work in the Lighthouse Depot, in Staten Island, December, 1877, Henry"s right hand became in a paralytic condition. This foretold that the end was near. He died at noon, May 13, 1878, asking, with his latest breath, which way the wind came, as though still thinking how to save human lives in a fog at sea. He was buried May 16, at Rock Creek Cemetery, near Georgetown, D. C. He was ready when death came. Two weeks before, he said to a friend: "I may die at any moment. I would like to live long enough to complete some things I have undertaken, but I am content to go. I have had a happy life, and I hope I have been able to do some good."
Several times during his connection with the Smithsonian Inst.i.tution he was offered more lucrative positions, but he remained where he believed he could be most useful. He was called to the professorship of chemistry in the Medical Department of the University of Pennsylvania, with double the salary of his secretaryship; but he declined. He was urged also to take the presidency of the college at Princeton. John C. Calhoun desired him to accept a professorship in the University of Virginia, as there were so many difficulties in connection with the secretaryship. Henry declined, saying that "his honor was committed to the inst.i.tution."
Calhoun grasped his hand, exclaiming, "Professor Henry, you are a man after my own heart."
He seemed to have no time to acc.u.mulate money. Fortunately, a fund of forty thousand dollars has been raised by friends, the income of which goes to his family during life, and afterwards to the National Academy of Sciences, to be devoted to original research.
In character he was above reproach. He said, "I think that immorality and great mental power exercised in the discovery of scientific truths are incompatible with each other; and that more error is introduced from defect in moral sense than from want of intellectual capacity."
He loved nature. "A life devoted exclusively to the study of a single insect," he said, "is not spent in vain. No animal, however insignificant, is isolated; it forms a part of the great system of nature, and is governed by the same general laws which control the most prominent beings of the organic world." In 1870, when gazing upon the Aar glacier, from the Rhone valley, he exclaimed to his daughter, while the tears coursed down his cheeks: "This is a place to die in. We should go no further." A really great man is never afraid to show that he has a tender heart.
He loved his home. Out from it, in his early married life, two children went by death, and later, an only son in his early manhood. Three daughters were left him. One of them records in her diary: "Had father with us all the evening. I modelled his profile in clay, while he read "Thomson"s Seasons" to us. In the earlier part of the evening he seemed restless and depressed, but the influence of the poet drove away the cloud, and then an expression of almost childlike sweetness rested upon his lips, singularly in contrast, yet beautifully in harmony, with, the intellect of the brow above."
Again she writes: "We were all up until a late hour, reading poetry with father and mother, father being the reader. He attempted "Cowper"s Grave," by Mrs. Browning, but was too tender-hearted to finish the reading of it. We then laughed over the "Address to the Mummy," soared to heaven with Sh.e.l.ley"s "Skylark," roamed the forest with Bryant, culled flowers from other poetical fields, and ended with "Tam O"Shanter." I took for my task to recite a part of the latter from memory, while father corrected, as if he were "playing schoolmaster.""
He was orderly and painstaking in his work, deciding with great caution.
Prof. Asa Gray tells a story of his boyhood which well ill.u.s.trates this.
"It goes back to the time when he was first allowed to have a pair of boots, and to choose for himself the style of them. He was living with his grandmother, in the country, and the village Crispin could offer no great choice of patterns; indeed, it was narrowed down to the alternative of round toes or square. Daily the boy visited the shop and pondered the alternatives, even while the manufacture was going on, until, at length, the shoemaker, who could brook no more delay, took the dilemma by both horns, and produced the most remarkable pair of boots the wearer ever had; one boot round-toed, the other square-toed.... He probably never again postponed decision till it was too late to choose."
A single incident ill.u.s.trates the kindness of the man, who was always called the "model of a Christian gentleman." "Early in the war, in the autumn of 1861, a caller at the presidential mansion, very anxious to see the chief magistrate of the nation, was informed that he could not then be seen, being engaged in an important private consultation. The caller, not to be repulsed, wrote on a piece of paper that he must see Mr. Lincoln personally, on a matter of vital and pressing importance to the public welfare. This, of course, secured his admission to the presence of Mr. Lincoln, who was sitting with a middle-aged gentleman.
Observing the hesitancy of the visitor, the President told him he might speak freely, as only a friend was present.
"Whereupon the visitor announced that for several evenings past he had observed a light exhibited on the highest of the Smithsonian towers, for a few minutes, about nine o"clock, with mysterious movements, which, he felt satisfied, were designed as signals to the rebels encamped on Munson"s Hill, in Virginia. Having gravely listened to this information with raised eyebrows, but a subdued twinkle of the eye, the President turned to his companion, saying, "What do you think of that, Professor Henry?"
"Rising with a smile, the person addressed replied that, from the time mentioned, he presumed the mysterious light shone from the lantern of an attendant who was required at nine o"clock each evening to observe and record the indications of the meteorological instruments placed on the tower. The painful confusion of the officious informant at once appealed to Henry"s sensibility, and, quite unmindful of the President, he approached the visitor, offering his hand, and with a courteous regard counselled him never to be abashed at the issue of a conscientious discharge of duty, and never to let the fear of ridicule interfere with its faithful execution."
Henry had learned how to triumph over the misfortunes of life. In 1865, the Smithsonian building was partially burned, with nearly one hundred thousand letters, his notes of original research for thirty years, the annual report in ma.n.u.script, ready for the press, a valuable library, etc.
"A few years ago," he said, "such a calamity would have paralyzed me for future efforts, but in my present view of life I take it as the dispensation of a kind and wise Providence, and trust that it will work to my spiritual advantage."
A bronze statue of Joseph Henry, by W. W. Story, costing fifteen thousand dollars, was unveiled in the grounds of the Smithsonian Inst.i.tution, April 19, 1883. Ten thousand people were a.s.sembled to witness the ceremonies. Noah Porter, ex-president of Yale College, delivered the oration. There it will tell the story of a self-made man--of whom Garfield said: "Remembering his great career as a man of science, as a man who served his government with singular ability and faithfulness, who was loved and venerated by every circle, who blessed with the light of his friendship the worthiest and the best, whose life added new l.u.s.tre to the glory of the human race, we shall be most fortunate if ever in the future we see his like again."
Prof. Joseph Henry was succeeded by Prof. Spencer F. Baird as secretary of the Smithsonian Inst.i.tution. He died August 19, 1887, and Prof. S. P.
Langley was called to the position, accepting the office November 18, 1887. The mantle of Henry has fallen upon a worthy successor; a scholar who has given us, among other works, the "New Astronomy," whose beauty of diction, breadth of knowledge, and exquisite ill.u.s.trations are so well remembered, as it appeared first in the pages of the Century Magazine.