\Wl)NIVER% .vlOSANGElfjV ^ 
 
 <: S 
 3 =? 
 
 I ^ 
 
 s 
 I? & 
 
 5 r*l 
 
 ^ ^ , * 
 
 >&AaV! 
 
 
 
 
 11 
 
 
 
 I* . 9
 
 
 JOSEPH HENRY 
 
 MAGNETIC TELEGRAPH 
 
 AN ADDRESS 
 
 DELIVERED AT PRINCETON COLLEGE, ME 16, 1885, 
 
 BY 
 
 EDWARD N, DICKERSON, LL.D. 
 
 "SI MONUMENTUM QU/ERIS CIRCUMSPICE. " 
 
 NEW YORK 
 SCRIBTsTER'S SONS 
 
 1885
 
 JOSEPH HENRY 
 
 MAGNETIC TELEGRAPH 
 
 A.N ADDRESS 
 
 DELIVERED AT PRINCETON COLLEGE, JUKE 16, 
 
 BY 
 
 EDWARD N, DICKERSON, LLD, 
 
 "SI MONUMENTUM QUARTS CIRCUMSPICE. 
 
 NEW YORK 
 CHARLES SCRIBNER'S SONS 
 
 1885
 
 CO 
 
 oo 
 
 CD 
 
 TK 
 
 COLLEGE OF NEW JERSEY, 
 PRINCETON, N. J., June 19, 1885. 
 
 MY DEAR SIR: 
 
 Immediately after the delivery of your paper 
 on the discoveries of Dr. Joseph Henry, I ex- 
 pressed my strong personal desire to see it pub- 
 lished. 
 
 I find that the College is at one with me in this 
 wish. 
 
 We should like to have so comprehensive a 
 paper circulated in our day, and handed down 
 to posterity. 
 
 I am yours ever, 
 
 2 JAMES McCOSH. 
 
 u 
 
 EDWARD N. DICKERSON, LL.D. 
 
 1C 
 
 c 
 
 3 
 

 
 Ntew YORK, June 22d, 1885. 
 MY DEAR SIR : 
 
 I take pleasure in furnishing to Princeton Col- 
 lege my address presenting the memorial tablet of 
 Professor Henry. I have added to it an appendix 
 of notes supporting the statements contained in it, 
 which I trust will prove satisfactory. 
 
 It is a labor of love for me to do anything 
 tending to present our great and beloved friend to 
 his own age, and to posterity, in his true propor- 
 tions. His achievements seemed to him so easy 
 to perform, that he never looked upon them as 
 exhibiting any great power ; and he therefore 
 involuntarily shrank from that praise to which 
 he was so eminently entitled, and from conspic- 
 uously exhibiting his results before the world. 
 He preferred to defer to the judgment of posterity, 
 and to submit his reputation to the ordeal of 
 time, which, like a simple acid, eats away the baser 
 metal, and leaves the pure gold free from its asso- 
 ciation. 
 
 With many thanks to you for the compliment 
 implied in your request, 
 
 I am, sir, very truly, 
 
 Your obedient servant, 
 
 EDW. N. DICKERSON. 
 President McCosn, 
 
 Princeton College.
 
 MEMORIAL ADDRESS 
 
 DELIVEBED BY 
 
 EDWARD N. DICKER80N, LLD,, 
 
 PRESENTING TO PEINCETON COLLEGE A TABLET DESIGNED TO 
 
 COMMEMOBATE THE CONTRIBUTIONS TO THE 
 
 ELECTRIC TELEGRAPH OF 
 
 JOSEPH HENRY. 
 
 MR. PRESIDENT AND GENTLEMEN, TRUSTEES OF THE 
 COLLEGE OF NEW JERSEY : 
 
 The pleasing but sad duty has been assigned to 
 me of presenting to you this memorial tablet of 
 the beloved master, who once shed the lustre of his 
 genius over this ancient seat of learning, and once 
 attracted to its classic shades, allured by his great 
 reputation, pilgrims from all lands, to drink from 
 the living font of knowledge, ever replenished 
 and refreshed by his ceaseless contributions. 
 
 I commit this monument to your tender care. 
 May it ever remain enshrined in this beautiful 
 temple. May its presence encourage those, and 
 the successors of those, to whom he delivered his 
 torch of science r ablaze with a light which had
 
 PROFESSOR HENRY AND THE 
 
 penetrated to the farthest ends of the earth, to 
 tend that sacred flame; so that when they shall 
 transmit it to their successors, it shall still be 
 borne high aloft in the upper atmosphere of pure 
 truth, with still increasing lustre a guiding 
 beacon to the wayfarer, wandering and astray 
 in the gloomy valleys of ignorance those deep 
 defiles, where the shadows seem ever darkening 
 by contrast with the brightening mountain tops 
 illumined by the rising sun of knowledge. 
 
 May it inspire the ingenuous youth, who in the 
 thronging years of the future shall gather about 
 these altars, to search the character and achieve- 
 ments of the great master; that they may be taught 
 by him how to study; how to think; how to work; 
 how to live; and how to die. 
 
 May it continue to remind those who annually 
 are attracted here to witness the evidences of the 
 growth of knowledge, as they are exhibited in the 
 commencement seasons, that once this college was 
 honored by the ministrations of Joseph Henry, 
 an American, who, with means created almost 
 wholly by himself, rivalled the achievements of 
 the greatest scientists of the old world, working 
 with the resources of nobly-endowed institutions, 
 and encouraged by the bounty of Kings; and for 
 years was ever a leader in the vigorous attack 
 upon the arcana of nature, made by the champions 
 of science in the early years of this century.
 
 MAGNETIC TELEGRAPH. 
 
 For those of us who enjoyed the happiness of 
 knowing him well, and loving him dearly, no 
 sculptured marble is needed to stir our hearts, or 
 keep fresh in our memories that noble presence, 
 which at once charmed and satisfied our senses. 
 Nor, if the chisel of the artist were guided by the 
 genius that once inspired Phidias, would it be 
 capable of fixing upon dull, cold marble more than 
 one of the almost infinite variety of expressions 
 revealing to the world without the exalted being 
 within. 
 
 But to those who have never seen him, or having 
 seen him have never known him, and to those who 
 shall come after us, it will be something to look 
 upon this marble, and inspired by the thoughts he 
 uttered, and the deeds he did, contemplate its calm 
 expression, and imagine what must have been the 
 living man. 
 
 In the year 1839, nearly half a century ago, 
 brought here as a student, I first saw Professor 
 Henry. I remember it well the time, the place, 
 and the surroundings. Boyish imagination had 
 pictured the great discoverer as a venerable man, 
 bowed down with the toil of years, bearing the 
 furrows, with which overtasked nature revenges 
 herself, traced upon his brow : such a person, 
 perhaps, as the artist has presented to us in the 
 familiar picture of Humboldt in his library.
 
 8 PROFESSOR HENRY AND THE 
 
 How different the reality ! In the maturity of a 
 perfect manhood he stood : 
 
 " A combination, and a form indeed, 
 Where every God did seem to set his seal, 
 To give the world assurance of a man." 
 
 His clear and delicate complexion, flushed with 
 perfect health, bloomed with hues that maidenhood 
 might envy. Upon his splendid front, neither 
 time, nor corroding care, nor blear-eyed envy, 
 had written a wrinkle, or left a cloud ; it was 
 fair and pure as monumental alabaster. His 
 erect and noble form, firmly and gracefully 
 poised, would have afforded to an artist an ideal 
 model for an Apollo. The joy of conflict and of 
 triumph beamed from his countenance a conflict 
 in which, for years, he had struggled with the 
 phantoms that guard the hidden treasures of 
 nature, and had ever been victorious. And above 
 all, surmounting all, infinite charity and gentle- 
 ness like the charity and gentleness of a loving 
 mother for her erring children. 
 
 To him the youthful student bowed down in 
 profound admiration. To him, and to his memory, 
 for nearly fifty years, he has clung with ever-in- 
 creasing love and affection. And now that seven 
 years have passed away since death severed the 
 bond strengthened by a life-time of intimacy, 
 he recurs with fondest memories to the many 
 happy occasions when it was his good fortune
 
 MAGNETIC TELEGRAPH. 
 
 to spend hours in sweet and instructive converse 
 with this gifted mortal, to whom the whole book of 
 nature was an open volume, out of which he ever 
 read lessons of wisdom, and beauty, and truth. 
 
 As Professor Henry appeared in 1839, so he con- 
 tinued till 1847, with but little change in the 
 physical man only that change, which, like the 
 changes in the early autumn, lightly touched with 
 tints of exquisite beauty the mature growth of 
 spring-time and summer ; and then, with extreme 
 reluctance, he departed from Princeton, called by 
 his country to lay down the arms with which, as 
 a soldier in the ranks, he had been waging his war- 
 fare against ignorance, and take command of the 
 intellectual forces to be summoned and organized 
 by him in the same glorious cause. 
 
 Born in the dying moments of the eighteenth 
 century, his age was marked by the numbers 
 denoting the years of the nineteenth. Like the 
 century, with whose growth his growth kept 
 pace, he had developed with almost unexampled 
 rapidity; and at the age of thirty-two, when he 
 took his chair here, although "he was but a 
 "youth, and ruddy, and of a fair countenance," 
 and was armed only with a simple sling of his 
 own construction, and pebbles from the brook 
 of nature, he was equal to the trained warriors 
 of maturer growth and superior armor, waging 
 war against the Goliah that guarded the unex-
 
 10 PROFESSOR HENRY AND THE 
 
 plored regions of nature's secrets; and like the 
 great king of Israel, after the brunt of the battle 
 was over, he came to be leader of the hosts, who 
 once had been tending only a "few sheep in the 
 wilderness." 
 
 Let us contemplate for a moment the intellectual 
 stature of our departed teacher, considered merely 
 as an investigator of natural laws, and measured by 
 the standard established by the intellectual world. 
 
 It is in the order of nature that the intermittent 
 progress of humanity is made under the guidance 
 of gifted men, appearing from time to time, who 
 push forward the outposts of truth, whether in 
 morals or physics, calling upon their fellow-men 
 to hasten and occupy the newly-conquered fields. 
 The names of such men are few, and are writ- 
 ten upon the rolls of fame. Their glory be- 
 longs to no nation, but to all mankind. Some- 
 times simultaneously and in different parts of the 
 world two such appear, who seem to have 
 been cast in similar moulds, lest perchance one 
 might die or fail, and progress stand still. Such 
 men were Henry and Faraday, whose intellects 
 were moulded with the same capacities, and who 
 worked out their tasks in the same spirit. If 
 either one had died before his work was done, the 
 other was capable of doing it ; and, in fact, both 
 in many cases struck out the truth, each uncon-
 
 MAGNETIC TELEGRAPH. 11 
 
 scious that the twin thought had been born in the 
 brain of the other. 
 
 To those devoted friends and admirers of Fara- 
 day, who delight in singing his well-earned praises, 
 and who best comprehend his achievements, it 
 seems that his discovery that electricity might 
 be produced from magnetism was his grandest 
 result. Upon it depends many of the most 
 important applications of electricity to the uses 
 of man ; and in the near future many more 
 are coming. Tyndall, the successor of Faraday, 
 does not restrain his enthusiasm when he contem- 
 plates this achievement. " I cannot help think- 
 " ing, "says he, "while I dwell upon them, that 
 " this discovery of magneto-electricity is the 
 " greatest experimental result ever obtained by 
 " an investigator. It is the Mont Blanc of Far- 
 " aday's own achievements. He always worked 
 " at great elevations, but higher than this he never 
 "subsequently attained."* 
 
 Let us accept the standard, and apply it to 
 Henry; let the achievement measure the power 
 of the man. 
 
 In November, 1831, Faraday read before the 
 Eoyal Society his memorable paper "On the 
 Evolution of Electricity from Magnetism," 
 illustrated by drawings of the apparatus, in 
 which Figure 1 is the compound "spool," dis- 
 
 * See Appendix, Note A.
 
 12 PROFESSOR HENRY AND THE 
 
 covered by Henry in 1828, and which Faraday 
 used in making his discovery.* No publica- 
 tion referring to this paper had reached this 
 country till April, 1832, when a vague reference, 
 made to it in the "Annals of Philosophy," was seen 
 by Henry, which led to his publication of July, in 
 " Sillimari's Journal" where he gave a full ac- 
 count of this great discovery, made by himself 
 before he heard of Faraday's work, which, when 
 compared with Faraday's paper of November, 
 exhibits Faraday's experiment for solving the 
 problem. When he wrote his paper, Henry, 
 mislead by the imperfect statement in the 
 " Annals of Philosophy " supposed that his experi- 
 ment had differed from Faraday's, but was un- 
 deceived when the full publication reached him. 
 In 1831, a teacher in the Albany Academy was 
 very remote from London, and the Eoyal Society. 
 
 In that same year, and in the same few weeks, 
 Faraday first, and Henry after him, independently 
 made the discovery of magneto -electricity; "the 
 " greatest experimental result ever obtained by 
 " an investigator," in the opinion of Tyndall.f 
 
 In the same field, and during the same years, 
 were the other great scientists of the world, study- 
 ing the same subject : Ampere, Arago, Oersted, 
 Davy, and a host of others; but these two did it, and 
 
 * See Appendix, Note B. 
 t See Appendix, Note C.
 
 MAGNETIC TELEGRAPH. 13 
 
 not the others ; and Henry did it by devices of his 
 own invention, unaided by anything which Faraday 
 had discovered or produced, while Faraday used 
 Henry's electro-magnet in performing his most 
 important experiment. 
 
 The towering heights which were scaled by the 
 daring spirit of Faraday from the East, were at the 
 same time surmounted from the West by our own 
 countryman. Both were climbing from opposite 
 sides at the same time, and neither was conscious 
 of the other's efforts till both stood, face to face, 
 upon the summit. Had Henry been furnished 
 with the corps of trained mountain guides, and 
 Alpine- stocks, such as attended Faraday in his 
 ascent, perhaps his foot would have first trodden 
 the peak, and Prof. Tyndall's song of triumph have 
 been addressed to him. 
 
 But when we compare Henry with Faraday, 
 who is the acknowledged unit of comparison, the 
 accidental conditions under which both existed 
 and worked must be known, or justice cannot be 
 done. Electrical science was the field to which 
 both spontaneously directed their studies. Its 
 mysteries at once excited curiosity, and baffled re- 
 search. Its most obvious phenomena had only for 
 a short time been recognized, and everything was 
 to be learned. What they did in that science, not 
 only constitutes the greater part of their claims 
 to reputation as investigators, but is almost the
 
 14 PROFESSOR HENRY AND THE 
 
 whole of our present knowledge of magneto- elec- 
 tricity. 
 
 But how superior in every respect, except in 
 God-given intellect, was the equipment of Fara- 
 day. He was eight years older than his rival. In 
 the year 1813 he was appointed "assistant" in 
 the laboratory of the Royal Institution, under Sir 
 Humphrey Davy, then one of the foremost scien- 
 tists of the world, who, attracted by Faraday's 
 genius, was directing his studies and forming his 
 mind. At that time Henry was but THIRTEEN 
 
 YEARS OLD. 
 
 In the next twelve years Faraday was at 
 work, with all the resources of the Royal 
 Institution, under the instruction of the great 
 Davy, in acquiring the knowledge with which he 
 was armed when he began his original investiga- 
 tions ; while Henry, during that same period, was 
 struggling unaided for such education as might 
 be obtained from the scanty resources of a country 
 town ; and with that proud independence, ever 
 so marked a feature of his character, was sup- 
 porting himself by teaching to others a part of 
 that which he was learning himself. 
 
 In 1825, Faraday had so improved his great op- 
 portunities, that at the age of thirty-four he was 
 appointed "director of the laboratory " of the Royal 
 Institution, where everything that science could 
 suggest, and money procure, was at his command
 
 MAGNETIC TELEGRAPH. 15 
 
 in aid of research. Henry was then a private tutor 
 in a distinguished family at Albany ; studying 
 mathematics in hours when his duties to his 
 pupils had ceased, and when other young men 
 might have thought they had earned the right to 
 relaxation and enjoyment. 
 
 In 1824, before Henry ever had in his hands 
 any instruments for research in electricity, Fara- 
 day, thus trained and equipped, began his attack 
 upon the problem of magneto- electricity and 
 failed ; and in 1830 it was not yet solved. 
 
 The discoveries of deductive science need no ap- 
 paratus. They are made and matured in the 
 brain ; and to record them is the only physical 
 incident to their existence or development. 
 Plato would have looked with disgust and 
 contempt upon a laboratory ; and would have 
 scorned the suggestion that time, or place, or 
 physical surroundings, could affect the workings 
 of his mind, or influence his deductions. But the 
 new philosophy, which has changed the face of the 
 world, is of no such ethereal nature. It is born in 
 observation of physical things; it is nurtured upon 
 experiments that cost money, and time, and labor; 
 its maturity is in perfected arts, and in things 
 to be seen, and handled, and enjoyed by the 
 senses; its end is to subordinate the blind forces of 
 nature to the uses of man to mitigate the ills, and 
 multiply the joys of life. They who are the ser-
 
 16 PROFESSOR HENRY AND THE 
 
 vants of this philosophy, must be provided with 
 materials with which to reproduce, in miniature, 
 the conditions that exist in nature in grander pro- 
 portions, or they cannot ask the questions whose 
 answers they are seeking; and, other things being 
 equal, he who is well provided with all these need- 
 ful things, has an immense advantage over another 
 who lacks them. 
 
 For thirteen years Faraday had been pursuing his 
 investigations amply supplied, and was in the full 
 career of successful experiment when, in 1826, his 
 great rival first looked upon the course over which 
 he was to run ; and even then Henry had to depend 
 upon the meagre facilities of the Albany Academy, 
 and the voluntary assistance of an appreciative 
 physician, Dr. Philip Ten Eyck, of Albany a 
 name to be held in grateful remembrance by all 
 who feel a pride in the achievements of the great 
 scientist, whose early efforts were assisted, and 
 whose hopes encouraged, by this enlightened 
 friend. 
 
 With such a beginning as this, who could expect 
 that the young aspirant for fame should ever 
 overtake his great leader in the friendly contest ? 
 And when he did overtake him, and in some im- 
 portant investigations surpass him, who shah 1 deny 
 that Henry, as a physical investigator, was the 
 equal of him above whom it is conceded no other 
 man has risen in this century !
 
 MAGNETIC TELEGRAPH. 17 
 
 In still further pursuing his researches into the 
 subtle phenomena of electricity, Henry made, here 
 in Princeton, another capital discovery, this time 
 in advance of Faraday, which forms an important 
 element in the science of electricity. It is to 
 be found detailed in any school book, under the 
 name of " Henry's Coils." His wonderfully elab- 
 orate investigations will be remembered by the 
 students of that day; as it was conducted in part 
 in the open air. Wires stretched across the cam- 
 pus, in front and in rear of Nassau Hall, were 
 the means by which the questioner was cross- 
 examining nature, and wresting from her reluct- 
 ant grasp her hidden secrets. At that time tele- 
 graph wires did not exist; and those fine lines 
 traced across the sky, excited the liveliest interest 
 in the students, whose fantastic guesses as to their 
 significance were the cause of much pleasantry in 
 the idle hours. 
 
 In the course of these investigations it was also 
 the good fortune of our scientist to first discover 
 the very curious phenomenon of "self induction," 
 as it is now called, which plays so important a 
 part in the creation and use of electric currents on 
 wires, sometimes injuriously and sometimes ben- 
 eficially. Without the knowledge of its laws no 
 duplex or quadruplex telegraph could be practically 
 operated; with that knowledge it can be neutral- 
 ized when it is injurious, and made available when
 
 18 PROFESSOR HENRY AND THE 
 
 useful. The brilliant spark which follows the 
 pulling of the pendant, attached to an electric 
 lighter for inflaming a gas jet, now in common 
 use, is one of the valuable practical applications 
 of this principle so discovered. 
 
 In contemplating the discoveries of the scientist 
 there are two aspects in which they present them- 
 selves. In one view we consider merely the diffi- 
 culty of the achievement; in the other, the value 
 of the result to mankind. The first view is ob- 
 vious when the thing is done; the other is to be re- 
 served fora future day, when all the consequences 
 have followed the original cause. The first view 
 is that which measures the power of the man 
 just as the lifting of a huge weight by some Her- 
 cules exhibits his strength, even though the 
 thing done may be, or may seem to be, useless. 
 The capital discoveries I have named, made by 
 Henry and Faraday, exhibited the giant's strength 
 when they were made, and measured the men 
 who made them. They were found at great 
 depths below the surface, where mental vision can 
 only penetrate by the aid of lenses, constructed in 
 advance, in accordance with the very laws for 
 whose discovery they are needed creations of the 
 scientific imagination, and called scientific hy- 
 potheses. In such creations Professor Henry was 
 excelled by no man. 
 
 Time will not permit even a hasty review of all
 
 MAGNETIC TELEGRAPH. 19 
 
 the scientific labor done by Professor Henry at 
 Princeton, during those years when his chief duties 
 were instruction, and when he had only a portion 
 of his time in which to work for mankind and for 
 reputation ; and I must be content with a passing 
 glance at a part of it. 
 
 Among those wires which were strung across 
 the campus in 1835, was one used for a mag- 
 netic telegraph between the professor's home and 
 his laboratory in the Philosophic Hall; and that 
 telegraph line was the first in the world in which 
 the galvanic circuit was completed through the 
 earth one end of the single wire-circuit ter- 
 minating in the well at the house, and the other 
 in the earth at the Hall. Steinheil, in Munich, 
 in 1837, worked his electric telegraph in the 
 same way by a single line wire, using the earth 
 as part of the circuit, over much longer distances; 
 but it was first done in this campus. 
 
 Nearly a century earlier our great countryman, 
 Franklin, had drawn from a surcharged thunder- 
 cloud, upon the string of a kite, in a pouring shower 
 of rain, the lightning of heaven, and had demon- 
 strated its identity with the puny spark of an 
 electrical machine; and with that capital experi- 
 ment his fame is more closely associated than with 
 any other of the great truths he discovered. In 
 these grounds that experiment was amplified, and 
 still further results obtained, by the man for
 
 20 PROFESSOR HENRY AND THE 
 
 whom the mantle of Franklin had been waiting 
 all those years, and who was the only American 
 whose stature would not have been dwarfed by 
 assuming it. 
 
 From the clear, blue sky, with two kites, one 
 above and assisting the other, held by a delicate 
 wire wound on an insulated reel, Professor Henry 
 drew down streams of brilliant sparks, intensified 
 by the self-induction of the wire itself; thus prov- 
 ing the electrical relations of the earth and its 
 envelope. So, a child's plaything in the hands 
 of a master, reveals the hidden mysteries of the 
 universe. 
 
 Away beyond the distant horizon we see at 
 times a quivering illumination of the sky, but hear 
 no thunder. How shall that phenomenon be ques- 
 tioned ? Fifty years ago, Henry converted the 
 metallic roof of his house into a great induc- 
 tive plate, by soldering to it a copper wire, and lead- 
 ing that through an electro-magnetic coil to the 
 ground; and with that he held converse with the 
 distant lightning, so far away that its voice could 
 not be heard. If the gods of mythology, who 
 hurl their thunderbolts, have a system in their 
 signals, this apparatus would enable us to read 
 their thoughts. Within a few months, a de- 
 vice has been put into operation by which tele- 
 graphic communication is kept up between the 
 running cars on railroads and the stations, so
 
 MAGNETIC TELEGRAPH. 21 
 
 that the positions of all the trains may at any 
 time be known, and protection against collisions 
 assured. To do this the metallic roof of the car 
 is used as an inductive plate, just as was the house 
 roof fifty years ago; and a wire passes from 
 it through a signaling coil to the ground by way 
 of the metal wheels and track. Near the roof 
 outside, an electric wire is stretched on poles, 
 through which electric flashes, like lightning, are 
 sent, and they set up by induction in the roof 
 electric currents similar to those passing over the 
 wire, which are read as signals by the observer; 
 and, conversely, signals are sent from the roof to 
 the wire by induction coils in the car. The ex- 
 perimental demonstration in Princeton has not been 
 lost, though buried so long, and to-day it throws 
 another safeguard around our lives.* 
 
 The first electro-magnetic engine for generating 
 power was made by Henry, at Albany, in 1831.f 
 His clear mind was not deluded into the belief 
 that such an apparatus could supersede the steam 
 engine as an economical motor, and he warned the 
 world against that delusion. Zinc, as fuel in a bat- 
 tery, is more costly than coal in a furnace. Still, 
 he saw and said that in exceptional cases it might 
 be useful; a result now coming to pass, dependent, 
 however, upon the discovery of magneto electricity 
 
 * See Appendix, Note D. 
 t See Appendix, Note E.
 
 PROFESSOR HENRY AND THE 
 
 by which galvanic batteries are dispensed with, 
 and electricity, made in quantities from some 
 great and economical source of power, is distrib- 
 uted to Henry's machines wherever they may be. 
 
 In many volumes, some of which have perished 
 by fire, and some remain, were laid out lines and 
 plans of investigation by Professor Henry, needing 
 only leisure and means for their development, 
 covering fields where other investigators have 
 since reaped rich harvests of fame, but from which 
 he was debarred by the pressure of his other occu- 
 pations here. In those records are contained the 
 evidence that the great intellect, which did so much 
 with so little, was capable of grasping the whole 
 circle of physical science, and of enriching and 
 adorning any department of it to which his efforts 
 might be directed. 
 
 But he was destined for another career. A be- 
 nevolent Englishman, inspired by the noble ambi- 
 tion to aid in elevating mankind, had bequeathed 
 to the United States a great sum of money to be 
 used for " the increase and diffusion of knowledge 
 among men." It was a splendid gift, and a sacred 
 trust. Who was to be found equal to the task of 
 effecting this grand purpose ? The civilized world 
 was interested in that question. Mankind was the 
 beneficiary of the trust; and all men were entitled 
 to be considered in its administration. By the 
 common consent of the wisest and best of Europe
 
 MAGNETIC TELEGRAPH. 23 
 
 and America, Professor Henry of Princeton Col- 
 lege was selected, and solicited to assume that 
 onerous duty. What tribute was that to the 
 achievements, the attainments, and the character 
 of the man ! He must be famous, that his selec- 
 tion might at once command the assent of the 
 world ; he must be learned, that he might be able 
 to carry out the purposes of the donor; and he 
 must be virtuous, that he should not degrade the 
 high office to any base or selfish uses. And thus 
 he was called. 
 
 When brought to the parting of the roads, choice 
 was extremely difficult. On the one hand, a life 
 devoted to the most delightful of all pursuits the 
 searching out the laws of nature, which are the 
 thoughts of God ; a reputation already great and 
 daily growing ; and a happy home, surrounded by 
 congenial and loving friends, and undisturbed by 
 cares for the present or the future. On the other 
 hand, an abandonment of the field of scientific 
 research, where the harvest was abundant and the 
 laborers few ; and a surrender to others of the 
 prizes he saw glittering before him in the race 
 he was running ; and furthermore, a grapple with 
 the problems of organization and finance, and 
 with the discordant elements which the scheme of 
 the Smithsonian Institution would necessarily 
 evoke. He foresaw that he might find himself, after 
 some years had passed, like a giant shorn of his
 
 24 PROFESSOR HENRY AND THE 
 
 strength; on the one side outrun in the race where 
 he had ever been in the lead; and on the other so 
 hampered and crippled as to be unable to accom- 
 plish the great objects for which alone he was 
 about to abandon his first love. That high sense 
 of duty which governed him in every act of his 
 life decided the question, notwithstanding his firm 
 conviction that in accepting the trust he left the 
 happiest days of his life in the past. 
 
 Perhaps he might have decided otherwise if 
 Princeton College had been then as it is now. Per- 
 haps he then might have felt, that with such 
 ample resources at his command as are now to 
 be found here, his services to humanity might 
 be greater as a soldier in the ranks than as a 
 commander in the field. But at that time no one 
 had arisen among the friends of this institution 
 who, like the Medici of the fifteenth century, was 
 able at the same time to gather the wealth of the 
 world by the arts of honorable commerce, and to 
 appreciate that the gathered wealth of the world 
 owes its existence and preservation to science, to 
 art, and to literature ; and that therefore it is due 
 to education that it should be encouraged by 
 noble gifts, such as have enlarged the ca- 
 pacity of the College of New Jersey, and re- 
 flected honor upon the names of those whose gen- 
 erous hearts, guided by wisdom, have led them to 
 broaden these ancient foundations, and to arm
 
 MAGNETIC TELEGRAPH. 25 
 
 with improved facilities the workers who are here 
 devoting their lives to the advancement of knowl- 
 edge. All honor to such men.* Had such assist- 
 ance come earlier, the career of the great scientist 
 might have been different ; but it was not to be, 
 and thenceforth another life opened before him, 
 and another man was unfolded to the world. 
 
 Perhaps the highest praise that can be bestowed 
 upon any man, is to say of him that he is just 
 equal to all the duties ever imposed upon him, 
 and never above them ; that his reserves are 
 not called into action until the emergency re- 
 quires them. Such men are the great benefactors 
 of mankind. Such a man was the Secretary of the 
 Smithsonian Institution. The principles he laid 
 down for the administration of the noble gift of 
 Smithson required time for their development, 
 and promised no present brilliant results. The 
 foundations were to be laid deep in the earth, 
 where the laborer and his work were scarcely 
 to be seen by the passer-by. No popular ap- 
 plause would greet the achievement for years 
 to come, while popular clamor was ever 
 ready to cry out against the waste of time and 
 money that produced no instant fruits. ^The 
 man of clear purpose and resolute will stood guard 
 over the work; and with just force enough, and 
 no more, drove off the assailants till the foundations 
 
 * See Appendix, Note F.
 
 26 PROFESSOR HENRY AND THE 
 
 were all secure, the superstructure begun, and it 
 was strong enough to stand alonej 
 
 With the skill that would have adorned a pro- 
 fessional diplomatist, he temporized and compro- 
 mised, when he could no longer contend with suc- 
 cess ; with the dash that would have illustrated 
 a general, he attacked when the moment was pro- 
 pitious, and the adversary off his guard. With 
 the earnestness of sincere conviction, and the 
 directness of demonstration with which his scien- 
 tific training had armed him, he convinced, one 
 by one, those who opposed his views, until at last 
 the Eegents of the Institution, and Congress, sur- 
 rendered their judgments to his, and the field was 
 won. 
 
 A great library was the dream of Mr. Choate, the 
 most scholarly and persuasive of advocates; and, 
 as a regent, he possessed and wielded a formidable 
 power. It was hard to persuade him that a li- 
 brary does not "increase knowledge among 
 men," and that it is very likely to "diffuse" igno- 
 rance. To discover and accumulate new truths, 
 and to diffuse them over the whole earth, was the 
 Secretary's conception of the donor's intention; to 
 pile up in Washington a miscellaneous collec- 
 tion in print of old truths and old errors, was the 
 idea of the scholars; and they were so strong that 
 a temporary compromise was necessary. The 
 vigorous growth of the true conception at last
 
 MAGNETIC TELEGRAPH. 27 
 
 overshadowed the false one, and the library no 
 longer saps the life of the Institution. Professor 
 Henry always thought that over every library 
 portal should be written some such warning as 
 " Cave Canem " beware of the lies. 
 
 It was not till 1852 that the serious attacks upon 
 the Smithsonian came to an end. On the 24th 
 of June, of that year, a United States Agricul- 
 tural Convention met in the theatre of the 
 Smithsonian building. The plan to plunder the 
 Institution seems to have been carefully considered 
 and matured ; and the officers of the Smithsonian 
 were elected members of the convention. Stephen 
 A. Douglas was at that time at the height 
 of his power. He had risen from the ranks by 
 the arts of the politician, and was the most influen- 
 tial man in the Democratic party of that day. 
 Although not yet forty years old, he had just 
 succeeded in defeating General Cass in a contest 
 for the presidential nomination at Baltimore ; and 
 although he failed by a few votes to secure it, he 
 had thrown it to Franklin Pierce, of New Hamp- 
 shire, and thus kept it open for himself in 1856, 
 as the Western candidate of the party. 
 
 He was styled the " Little Giant " not in deris- 
 ion, but in admiration; as expressing the combi- 
 nation of a small stature and great intellect. 
 Eepresenting in the convention what was then 
 an almost entirely agricultural constituency, he
 
 28 PROFESSOR HENRY AND THE 
 
 thought that votes were to be got, and his influence 
 strengthened, if he could bring home to them the 
 spoils of the Smithsonian; and accordingly a reso- 
 lution was introduced petitioning Congress to 
 appropriate a portion of the Smithsonian money 
 for an agricultural bureau ; and Judge Douglas 
 undertook the congenial task of accomplishing 
 the raid. The recollections of that battle are 
 among the valued treasures of memory, asso- 
 ciated in my mind with Joseph Henry. In such 
 an assemblage, and with such a cause, Douglas 
 was an adversary to be feared by any man. 
 That he was an accomplished politician was 
 proved by his great success ; and he was there 
 to fix another step in the ladder by which he had 
 climbed so high. His speech was adroit, as only 
 he could make it. Its argument was founded upon 
 the proposition that civilized man depends upon 
 agriculture, without which barbarism would sweep 
 over the land; and his conclusion was that the 
 farmer was entitled to whatever assistance could be 
 got out of the money of Smithson, whose benevo- 
 lence could best be applied in encouraging those 
 who were, at the very foundations of civilization. 
 It would be great injustice to Judge Douglas to 
 assume that he supposed the diffusion of papers of 
 turnip seed among farmers was that sort of " in- 
 ' ' crease and diffusion of knowledge among men " 
 designed by Mr. Smithson ; but no doubt it would
 
 MAGNETIC TELEGRAPH. 29 
 
 be an increase and diffusion of the knowledge that 
 he was the friend of the farmer, and that was 
 of more importance to him. The Secretary, sur- 
 rounded by a few earnest friends, and prepared 
 for the assault, sat in the back seat of the 
 theatre quite unnoticed, kindling with righteous 
 indignation at this nefarious plot to confiscate 
 the funds of which he was the chosen guardian, 
 and to destroy the institution devised by his intel- 
 lect, reared by his unceasing efforts, and guarded 
 so far by his sleepless vigilance. 
 
 When the popular applause following the 
 " Little Giant's " popular speech had subsided, 
 the Secretary arose. In measured and digni- 
 fied words he presented himself as the guard- 
 ian of that fund, bound, so far as in him lay, 
 to defend it from spoliation. He first developed 
 the moral aspects of the question, and appealed, 
 over the head of the advocate, to the honesty 
 of the constituents he represented ; expressing the 
 most generous confidence that the farmers of this 
 country would never consciously be parties in an 
 attempt to seize that which belonged to mankind 
 in general, or seek by a forcible partition to destroy 
 the unity and efficiency of the fund. 
 
 The legal aspect of the question he next dis- 
 cussed like an equity lawyer ; and denounced in 
 scornful sentences that attempted breach of trust 
 which was implied in the resolution.
 
 30 PROFESSOR HENRY AND THE 
 
 And then, out of the fullness of his knowledge, 
 with abundance of illustration and example, he 
 demonstrated that the discovery of new truths, 
 and their application to the arts, had elevated the 
 farmers from the mere drudges they were in the 
 seventeenth century to their present high state of 
 intelligence and comfort. 
 
 The effect was overwhelming ; and the " Little 
 Giant " must have felt that there was another 
 "giant" there to whose title no diminutive prefix 
 could be properly applied. 
 
 The meeting adjourned till the next day, and 
 these significant words were written in the Secre- 
 tary's diary, under date of June 25 : "Judge 
 " Douglas, toward the close, made an apology for 
 " the warmth of his expressions. I did the same. 
 " Judge Rusk followed so the whole was am- 
 " icably settled." 
 
 Since that day no further assaults have been 
 made on the Smithsonian Institution; and it 
 stands a proud monument to the genius, the 
 learning, the labor, and the character of the great 
 Secretary; who was content to sink his personality 
 in the impersonal institution to be overshadowed 
 by the creature of his own creation, in order that 
 true knowledge might the better be increased and 
 diffused among men. 
 
 The conscientious obligation he felt pressing 
 upon him to lose no opportunity for diffusing
 
 MAGNETIC TELEGRAPH. 31 
 
 knowledge and correcting error, imposed a vast 
 amount of unrecognized and unrequited labor. 
 The intellectually halt, and lame, and blind, con- 
 tinually resorted to him for help, either in person 
 or by letter ; and they never were sent away 
 empty. Like the home of the lovely country parson 
 in the Deserted Village, 
 
 " His house was known to all the vagrant train ; 
 He chid their wanderings, but reliev'd their pain." 
 
 They who have witnessed some of those deeds 
 of charity, will never forget the gentle patience 
 with which he listened to the beggars for knowl- 
 edge, and the simple way in which he conveyed to 
 their imperfect intelligences the truths they were 
 seeking. Their self-conceit was often offensive ; 
 but he knew it was the product of ignorance, and 
 his effort was to cure the disorder. He was no 
 more repelled by the disagreeable symptoms, than 
 the physician is who must treat a loathsome disease. 
 On one occasion, in my presence, one of these crip- 
 ples refused to accept the instructions of the great 
 physicist, on a very simple question of dynamics, 
 applicable to a project he had in hand; but instead of 
 dismissing him, the master quietly took down "Hut- 
 ton" from the book-case, and patiently read that 
 author's confirmation of the law he had been teach- 
 ing. What an exhibition of true humility ! Per- 
 haps, thought he, " I can give a new direction to this
 
 PROFESSOR HENRY AND THE 
 
 " man's mind, who may yet do something useful ; 
 " and what matters it that he scorns me." 
 
 No one can form an adequate estimate of the vast- 
 ness of his mind, of the extent and accuracy of his 
 learning, and of his power to discern the correla- 
 tions of knowledge, who has not carefully read 
 the instructions mapped out by him for the guid- 
 ance of investigators working under the auspices 
 of the Smithsonian Institution. They constitute a 
 set of charts, which, for years to come, will guide 
 the explorer safely and surely in future voyages 
 for the discovery of new truths ; and are a monu- 
 ment, attesting the fidelity with which the great 
 trust was executed, and vindicating the sagacity of 
 those eminent men, who, in 1846, saw, what his 
 innate modesty forbade him to see, that Joseph 
 Henry was, of all living men, the most fit to ad- 
 minister a fund whose object was "the increase 
 "and diffusion of knowledge among men." 
 
 Passing by thus hastily the great achievements 
 illustrating the long and happy life of Henry, 
 let us examine with more particularity his connec- 
 tion with the electro-magnetic telegraph; whose 
 creation has so largely modified the course of mod- 
 ern civilization, and endowed the dull earth with 
 nerves, like those of the living frame, whereby the 
 whole body of mankind instantly feels the joys or 
 sorrows of any of its members. 
 
 How to communicate intelligence instantly, over
 
 MAGNETIC TELEGRAPH. 33 
 
 distances so great that the voice cannot be heard, 
 had been well known to organized societies from 
 remote antiquity. Visible signals, made by mov- 
 ing vanes by day, and lighted torches by night, 
 were known to Greeks and Eomans alike; and 
 more recently the alphabet was associated with 
 these movements, so that alphabetical messages 
 were freely communicated. 
 
 Even barbarous nations and tribes possessed this 
 art in a high degree of perfection; and the arrival 
 and progress of Cortes in Mexico were communi- 
 cated by telegraphic signals, corresponding with 
 the sign language of the Aztecs, to the capital of 
 the doomed Montezuma. 
 
 When atmospheric electricity came to be artifi- 
 cially generated, it occurred at once to ingenious 
 men that it might be used for telegraphy; and, in 
 1774, the first electric telegraph ever constructed 
 was established at Geneva by Lesage. He used 
 twenty -four wires, each connected with an electro- 
 scope, whose function it is to move when the wire 
 is charged with electricity, and by means of 
 which any of the letters of the alphabet could 
 be transmitted, by simply discharging a prime 
 conductor of an electrical machine into the 
 wire corresponding to that letter. This com- 
 plicated apparatus was subsequently improved 
 by using only one wire, and causing lettered 
 wheels to revolve synchronously at the two sta-
 
 34 PROFESSOR HENRY AND THE 
 
 tions, so that the same letter would appear at 
 the same time to both operators. By this appara- 
 tus, whose principle of synchronous revolution is 
 the same as that now used in the printing tele- 
 graph, the sender would simply close the circuit 
 on his electrical machine when his revolving 
 wheel presented the desired letter, and the pith-ball 
 electroscope, moving at the receiving end at the 
 same instant, would indicate to the receiver that 
 the letter then presenting itself to him on his 
 wheel was the one intended. 
 
 A number of other inventors used static elec- 
 tricity for the same purpose during the latter years 
 of the last century, and the earlier ones of this. 
 In England, Ronalds had a line of eight miles 
 on which the wire was suspended from poles, 
 and insulated by silken strings;* and in 1796, 
 Salva, in Spain, worked a line by static electricity 
 twenty-six miles long.f 
 
 In the year 1800 Volta produced the voltaic pile, 
 and gave to the world that new manifestation of 
 electricity called galvanism. In that form this 
 subtle agent is far more manageable than in 
 the form of static electricity; and by the use of 
 galvanic batteries a current of low tension, but 
 of enormously greater power, can be maintained 
 with little difficulty; whereas static electricity 
 
 * See Appendix, Note G. 
 t See Appendix, Note H.
 
 MAGNETIC TELEGRAPH. 35 
 
 is like lightning, and readily leaps and escapes 
 from the surfaces on which it is confined. The 
 galvanic current also readily decomposes acid- 
 ulated water, and many other substances, and 
 this capacity was soon applied to the purposes of 
 telegraphy. Scemering, in 1807, invented a tele- 
 graph on this plan, and continued it for several 
 years in Munich, publishing accounts of it in sci- 
 entific journals, and exhibiting it to learned socie- 
 ties.* Others followed his lead, until finally it 
 came into commercial use in England in 1846 as a 
 rival to the electro-magnetic telegraph of later 
 invention ; but requiring its aid, as an alarm.f 
 
 In 1820, Oersted discovered the capital fact that 
 a galvanic current, passing through a wire placed 
 horizontally above, and parallel to, an ordinary 
 compass needle, will cause that needle to sway on 
 its axis to the east or west, according to the direc- 
 tion of the current through the wire. At once 
 Ampere suggested the application of the new dis- 
 covery to the old telegraph, whereby galvanism 
 might be substituted for static electricity, and 
 the deflection of a magnetic needle for the diver- 
 gence of the pith balls of the electroscope. Baron 
 Schilling, a Eussian nobleman, inspired by the love 
 of science, accordingly took up this suggestion, 
 and constructed a galvanometer or needle tele- 
 
 * See Appendix, Note I. 
 t See Appendix, Note K.
 
 36 PROFESSOR HENRY AND THE 
 
 graph, which in a practical and operative form 
 was exhibited to the Emperor Alexander in 1824, 
 and came to be well known to scientific persons 
 at that time.* 
 
 In 1833, Gauss and Weber set up a single circuit 
 galvanometer telegraph on this plan at Gottengen, 
 leading the wire over the house-tops, on insula- 
 tors, as we do now; and by the deflections of the 
 needle to the right and left made up the alphabet, 
 as it had been done before when using other means 
 for moving the vanes, f 
 
 Their apparatus, however, is perfectly silent. 
 The needle is suspended by a thread when the noise- 
 less current sways it to and fro with but feeble 
 force; and it is incapable of calling the attention of 
 the operator to receive its message. These were 
 serious difficulties, to be overcome by other princi- 
 ples, and other inventions, which would supersede 
 this one. 
 
 Following Oersted, Arago, in France, in 1820, 
 made the next capital discovery. It was but 
 a little thing he saw simply that a sewing needle, 
 surrounded by a coil of wire, through which a vol- 
 taic current passed, had become magnetic; but that 
 little thing has grown to be mighty. This obser- 
 vation was the complete discovery of electro-mag- 
 netism, which had been dimly seen in Oersted's gal- 
 
 * See Appendix, Note L. 
 t See Appendix, Note M.
 
 MAGNETIC TELEGRAPH. 37 
 
 variometer; and was the germ of the electro-mag- 
 net. For four years this beautiful discovery was 
 experimented with by all the scientists in Europe 
 before another step was taken; and then William 
 Sturgeon, of England, produced the electro-magnet. 
 It consisted of a large soft iron wire, bent into 
 a horse-shoe form, coated with varnish, and 
 wrapped with a spiral coil of naked copper wire 
 from end to end, through which the voltaic cur- 
 rent might be passed. This bent wire became a 
 magnet while the current flowed, but lost its mag- 
 netism when the current ceased. 
 
 Here then was born into the world an apparatus 
 capable of exerting a stronger power at the will of 
 the operator, by merely opening and closing the 
 voltaic circuit; and it was then thought that the 
 difficulties in the way of the telegraph were con- 
 quered. The experiment was soon tried with 
 Sturgeon's magnet by Barlow, an eminent scien- 
 tist ; and in January, 1825, he published his results 
 in the "Edinburgh Philosophical Journal" in 
 these words: 
 
 " The details of this contrivance" (a telegraph) 
 " are so obvious, and the principle on which it is 
 " founded so well understood, that there was only 
 " one question which could render the result 
 " doubtful; and this was, is there any diminu- 
 " tion of effect by lengthening the conducting
 
 38 PROFESSOR HENRY AND THE 
 
 "wire?" If not, he proceeds to say: "Then no 
 " question could be entertained of the practicabil- 
 " ity and utility of the suggestion above adverted 
 "to. I was, therefore, induced to make the 
 " trial; but I found such a sensible diminution 
 " with only two hundred feet of wire, as at once 
 " to convince me of the impracticability of the 
 " scheme." 
 
 Barlow's experiment was repeated by other scien- 
 tists in that and following years with a like result; 
 until it came to be accepted in the scientific world 
 that the telegraph could not be worked with the 
 newly-discovered electro-magnetism. So strongly 
 was this fixed in the opinion of the day, that as 
 late as 1837 thirteen years after the invention of 
 the electro -magnet by Sturgeon so eminent a sci- 
 entist and discoverer as Wheatstone, pronounced 
 the electro- magnetic telegraph impossible, on an 
 occasion when the very question was submitted to 
 him for decision by Cooke, at the suggestion of 
 Faraday himself. This fact is so important, and 
 so conclusive on the question now under examina- 
 tion, that I read Wheatstone's own account of it, 
 submitted by himself to arbitrators who were to 
 decide a controversy between himself and Cooke 
 as to their respective merits as inventors of 
 one form of the electro-magnetic telegraph. He 
 says: "I believe, but am not quite sure, that
 
 MAGNETIC TELEGRAPH. 39 
 
 " it was on the first of March, 1837, that Mr. 
 " Cooke introduced himself to me. He told me 
 " he had applied to Dr. Faraday,* and Dr. Roget, 
 " for some information relative to a subject on 
 " which he was engaged, and they had referred 
 " him to me as having the means of answering 
 " his inquiries. * Relying upon my 
 
 " former experience, I at once told Mr. Cooke that 
 " it would not, and could not, act as a telegraph, 
 " because sufficient attractive power could not be 
 " imparted to an electro -magnet interposed in a 
 " long circuit; and to convince him of the truth of 
 " this assertion I invited him to King's College to 
 " see the repetition of the experiments on which 
 " my conclusion was founded. He came, and 
 " after seeing a variety of voltaic magnets which, 
 " even with powerful batteries, exhibited but slight 
 " adhesive attraction, he expressed his disap- 
 " pointment."-[ 
 
 Cooke confirms this statement by saying : "It 
 " was my inability to make the electro-magnet act 
 " at long distances which first led me to Mr. 
 " Wheatstone."i 
 
 Let the difficulty of making the discovery 
 which overcame this impossibility be judged by 
 the fact, that for so many years, such men as 
 these were unable to do it when it was needed; 
 
 * See Appendix, Note N. f See Appendix, Note O. 
 
 J See Appendix, Note P.
 
 40 PROFESSOR HENRY AND THE 
 
 and let that fact answer the envious suggestion 
 that Henry's achievement involved no great 
 amount of analytic and inventive power. 
 
 When Barlow's demonstration was published in 
 1824, Henry had never seen an electro-magnet, nor 
 tried an experiment in electricity. When, how- 
 ever, two years later he took up the subject, and 
 began the first set of regular scientific investiga- 
 tions ever attempted in the United States, he de- 
 duced from Ampere's law the principle that the 
 voltaic currents, carried on wires around the iron 
 core of the electro-magnet, should move in planes 
 at right angles to the axis of that core which 
 they could not do even approximately if the core 
 itself were insulated, as in Sturgeon's small 
 magnet, having only one coil of naked wire 
 wound spirally around it, necessarily leaving open 
 spaces between the successive spirals, and so lead- 
 ing the current like a cork screw around the core. 
 He also reasoned that, as the current must be led 
 through a spiral circuit, which theoretically should 
 be circular, the departure from its true course 
 might be counteracted by winding the wire on a 
 second spiral outside of the first, but with its 
 spiral angle opposed, so that the resultant of the 
 current from the two spirals would be the same as 
 if it revolved in planes at right angles to the axis 
 of the core. 
 
 He brought his reasoning to the test of experi-
 
 MAGNETIC TELEGRAPH. 
 
 ment. Instead of insulating the core, he wrapped 
 a fine copper wire with silk, and wound it on the 
 core; each spiral closely packed against its fellows, 
 so as to correct the spiral error as much as possible 
 in each layer; and then he wound the wire in a 
 second spiral over the first, but with the pitch of 
 the screw, so to speak, in the opposite direction. 
 And carrying out the principle he multiplied the 
 coils to an enormous extent in the same way. The 
 result justified and established his theory; and his 
 magnets at once showed a capacity hundreds of 
 times greater than any then known to science.* 
 
 But this was not all. Another step had to be 
 taken before Barlow's demonstration could be over- 
 thrown, and the telegraph made possible. And 
 this he took by discovering and establishing the 
 fact, that a magnet with a long fine wire coil must 
 be worked by a battery of "intensity," composed 
 of a large number of cells in series, when a distant 
 effect was required; and that the greatest dynamic 
 effect, close at hand, is produced by a battery of a 
 very few cells of large surface, combined with a coil 
 or coils of short coarse wire around the magnet. 
 
 These discoveries and inventions solved the 
 problem which had seemed to European scientists 
 insoluble; and in one account of them which was 
 published in " Sillimari's Journal" for January, 
 1831, he says : " The fact that the magnetic action 
 
 * See Appendix, Note Q.
 
 42 PROFESSOR HENRY AND THE 
 
 " of a current from a trough is at least not sensibly 
 " diminished by passing through a long wire, is 
 11 directly applicable to Mr. Barlow's project of 
 " forming an electro-magnetic telegraph."* This 
 reference was to Barlow's paper of 1824, in 
 which he had demonstrated the impracticability 
 of the telegraph. 
 
 Had these things been done in the Royal Institu- 
 tion, and read before the Royal Society, Wheatstone 
 would not have been found, in 1837, denying the 
 possibility of an electro-magnetic telegraph ; and 
 Faraday would have been able to answer Cooke's 
 question, without sending him to Wheatstone for 
 the information. In those days, however, the 
 United States were held in no higher estimation in 
 Europe, than Nazareth was in former days in 
 Jerusalem ; and no one in England read an 
 American book. 
 
 But not content with having reasoned out, and 
 demonstrated, that distance was no longer the sole 
 impediment in the way of the magnetic telegraph, 
 Henry, in 1831, established the first electro- 
 magnetic telegraph that ever existed. In the 
 Albany academy he strung a mile of line wire, 
 and with an "intensity battery " at one end, and his 
 spool of long fine wire at the other, he operated the 
 armature of the first sounding telegraph of any 
 kind. When the armature was attracted by 
 
 * See Appendix, Note R.
 
 MAGNETIC TELEGRAPH. 43 
 
 the magnet, it struck a small bell or sounder, 
 which spoke its signals ; and that apparatus there 
 was maintained to illustrate the telegraph to the 
 students. 
 
 When applied to practical use, some code of 
 signals must be arranged for translating the 
 successive taps of the armature ; but that was 
 well known in the telegraphic art for ages, 
 needing only good judgment in arranging it, 
 so that the letters which occur most frequently, 
 shall be represented by the smallest number of 
 motions ; just as Gauss and Weber arranged their 
 needle-telegraph code in 1833, when the movements 
 of their needle to and fro, in a number of simple 
 combinations, indicated the alphabet.* 
 
 These ' ' spools " of Henry have been the means 
 by which most of the great discoveries in electro- 
 magnetism have since been made. Faraday and 
 Henry used them in their famous researches already 
 referred to, in which they discovered magneto- 
 electricity. Sturgeon, in writing of them, says : 
 " Professor Henry has been enabled to produce a 
 " magnetic force which totally eclipses every other 
 " in the whole annals of magnetism; and no parallel 
 " is to be found since the miraculous suspension of 
 " the celebrated oriental impostor in his iron 
 " coffin, "f Without them we could not have the 
 
 * See Appendix, Note S. 
 t See Appendix, Note T.
 
 44 PROFESSOR HENRY AND THE 
 
 telegraph, or the still more marvelous telephone. 
 They are to-day essentials of modern living ; and 
 are as familiar to us as spools of cotton. Judg- 
 ing by their results, they constitute the most im- 
 portant discovery which has ever been made in 
 electricity since Volta created the battery. 
 
 Henry also put in operation at Princeton in 1835 
 the very simple and obvious plan of using the "in- 
 " tensity spool and battery," working through long 
 distances, to open and close the circuit of a "quan- 
 " tity spool and battery," stationed where the work 
 was to be done; thus making the powerful mag- 
 net, at short range, the servant of the weak one at 
 long range. In this state he left the problem 
 entirely solved, to those who could procure the 
 money to practically apply his discoveries to the 
 commercial uses of man. 
 
 That task was no easy one. In 1831 there were 
 no railroads and no steamships. Over rough 
 country roads the mails were carried in wagons or 
 coaches, and the postage on a single letter was a 
 shilling for short distances, and twice as much for 
 longer. But little capital had accumulated in this 
 country; and corporations, those powerful instru- 
 ments for uniting the slender means of the many 
 into a compact force for the development of great 
 industrial enterprises, were hardly known. If the 
 most perfect telegraph apparatus of to-day had 
 been then presented to the public, no company
 
 MAGNETIC TELEGRAPH. 45 
 
 could have been formed to exploit it. The time had 
 not yet come; nor could it come until railroads were 
 built, and the exchange of material things had 
 been rendered easy. 
 
 In Europe, where money and railroads were more 
 abundant, the telegraph was first put into practical 
 use. Wheatstone and Cooke, in England, in 1838, 
 having first, however, seen and talked with Henry 
 on the subject in 1837,* after they had first de- 
 cided the thing to be impossible, established a 
 practical commercial telegraph line between Pad- 
 dington and West Dayton, a distance of thirteen 
 miles ; and a shorter line was in Munich.f In 
 this country private capital could not be raised 
 for the purpose at all ; not because there was 
 any doubt that the thing could work, but because 
 no one supposed it would repay the investment ; 
 as it certainly would not have done in those early 
 days. At last Congress was induced to do what 
 private enterprise refused, and in 1844, six years 
 after the English lines had been in practical oper- 
 ation, and seven years after the Bavarian, money 
 was appropriated for the line between Baltimore 
 and Washington. This was accomplished, after 
 great exertions, by persons hoping for the reward 
 which a patent for some of the contrivances con- 
 nected with that particular plan promised. 
 
 * See Appendix, Note U. 
 t See Appendix, Note V.
 
 46 PROFESSOR HENRY AND THE 
 
 Neither in England, where Wheatstone had a 
 patent founded on Henry's inventions, nor here, 
 where Morse had a similar one, could the telegraph 
 have been introduced for years after it really 
 was, but for the beneficient operation of the patent 
 laws. But few men are to be found who will 
 incur the risks, and expend the money, incident 
 to the introduction of a new and untried industry, 
 without the hope of that pecuniary return, which in 
 such cases, can only be secured by the exclusive 
 use for a "limited time" of the new thing, during 
 which it is hoped the original losses maybe repaid, 
 and a profit earned.* 
 
 Let us now consider what would have been the 
 position of Henry in the world, if at any time 
 before his inventions had been so long in public 
 use that he had lost his rights, he had taken a 
 patent for. 
 
 First, his magnetic spools, pure and simple; 
 
 Secondly, the combination of a magnetic spool 
 of long fine wire, with an " intensity battery," for 
 the purpose of producing a practical magnetic 
 effect at great distances; 
 
 Thirdly, the combination with such an appa- 
 ratus of a quantity battery, operating upon a spool- 
 magnet of coarse and short wire, at a distance 
 from the intensity battery; whereby the great lift- 
 
 * See Appendix, Note W.
 
 MAGNETIC TELEGRAPH. 47 
 
 ing power of the quantity magnet might be con- 
 trolled by the intensity combination; 
 
 And finally, the combination of the intensity 
 battery and spool, with a vibrating armature, so 
 arranged as to strike a sounder when the circuit 
 is closed or opened at the sending end, for the 
 purpose of transmitting intelligible messages tele- 
 graphically. 
 
 All these he might have patented in the United 
 States at any time during several years after his 
 discoveries and inventions were made; and he 
 could have held them against the world. That he 
 was the first man to do all these things is not in 
 doubt anywhere. If he had taken such a patent, 
 as late as 1837, he would have controlled the 
 telegraph in this country, certainly until 1851; 
 and unless he had then been adequately rewarded 
 for his great inventions, his term would have been 
 extended till 1858. Imagine the good he would 
 have done to science had the wealth which this 
 would have produced been poured into his purse ! 
 
 But listen to his noble words: " At the time of 
 " making my original experiments in 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 de- 
 " clined, on the ground that I did not then consider 
 ' ' it compatible with the dignity of science to confine
 
 48 PROFESSOR HENRY AND THE 
 
 " the benefits which might be derived from it to the 
 " exclusive use of any individual." 
 
 Pure science was his beloved, and he could not 
 make merchandise of her. 
 
 When that sentence was written, other eminent 
 scientists had thought differently of this question, 
 and had patented their discoveries ; and lest he 
 might seem to cast a reproach upon them, and to 
 say "lam holier than thou," his humble spirit 
 added these words: "In this, perhaps, I was too 
 fastidious." 
 
 It must have occurred to him at times, when he 
 needed money for his experiments, and when he 
 saw the fruits of his labor enriching the world, 
 that he might have taken some share of the 
 wealth; but he would not taint with selfishness his 
 generous gift. How valuable in money it was he 
 knew full well. Even for that fragment of it, 
 then for six years by him given to the public, 
 which was carried to Morse in 1837 to enable 
 him to construct his special plan of a recording 
 telegraph in that year, now practically obsolete, 
 Dr. Gale, who carried it, received a share in 
 the patent which was founded upon it, and 
 without which it could not have existed. For 
 that share fifteen thousand dollars in cash were 
 subsequently paid to him. And its use for the 
 telegraph was but a small part of its infinite va-
 
 MAGNETIC TELEGRAPH. 49 
 
 riety of applications to the arts, and the purposes 
 of man. 
 
 Come with me now into a telegraph office, and 
 let us see what we find there. If the line be a 
 short one say thirty or forty miles you will see 
 but one of Henry's spools, fixed to a table, 
 having a piece of iron called an "armature," 
 capable of vibrating in front of its poles, and so 
 arranged that when the "spool-magnet" attracts 
 it, it will vibrate and strike a sounding-bar of 
 sonorous metal, which gives out distinctly the 
 sound of the tap. The "spool" is wound spirally 
 in layers with several hundred feet of fine copper 
 wire, covered with silk, in the manner specified 
 by Henry in " Sillimaris Journal." At the 
 other end of the line is a battery, composed of a 
 number of cells in series, called by Henry for 
 distinction an "intensity battery; " and the wire 
 circuit is supplied with a simple device, so that it 
 may be opened or closed by the operator's finger. 
 When he closes it, a current of electricity 
 flows from the "intensity battery" along the 
 wire, and around the coil of the ' ' intensity mag- 
 net," and the armature strikes the sounder and 
 gives the signal. The listener hears it; and as the 
 order of the taps progresses in accordance with 
 a pre-arranged artificial code, to express the let- 
 ters of the alphabet by combinations of succes- 
 sive taps just as the old visible signals were ar-
 
 50 PROFESSOR HENRY AND THE 
 
 ranged by combinations of the successive move- 
 ments of the vanes, or afterwards of the needle of 
 the Gauss and Weber telegraph he hears letter 
 after letter tapped out, and the message is under- 
 stood. 
 
 Now, that apparatus has nothing about it 
 more than was in Henry's Albany telegraph of 
 1831; nor could it operate if it omitted any one of 
 the inventions, either singly or together, which 
 were then for the first time combined. It depends 
 entirely upon the discoveries made by Henry before 
 1831; and it could not have existed in the world 
 earlier than those discoveries, by the use of any 
 means then known to man ; nor since by any 
 other means than those discovered by Henry. 
 
 Henry used a bell as a sounder; they now use 
 a metal bar and a sounding box. Henry reversed 
 the battery current, whereby no spring is needed 
 to withdraw the armature for the purpose of 
 vibrating it; and that is the common practice in 
 English and German telegraphs. Here they 
 generally merely interrupt the circuit, and the 
 armature is withdrawn from the magnet by a 
 spring; although Henry's device is also used here 
 largely, and is essential to the quadruplex instru- 
 ments.* 
 
 If, however, the telegraph line is a long one it 
 may be a thousand miles or more then you will 
 
 * See Appendix, Note X.
 
 MAGNETIC TELEGRAPH. 51 
 
 see two sets of Henry's spools, and two batteries. 
 One is the "intensity battery and spool" first de- 
 scribed; and the coil of fine wire maybe, and often 
 is, several thousand feet long while the battery 
 is composed of more than a hundred cells. The 
 distance being so great they do not attempt to 
 send force enough through the intensity circuit to 
 operate a sounder, but only to open and close the 
 local circuit of Henry's quantity battery and 
 spool. That circuit consists of a battery of but 
 one or two cells of large surface, and a spool 
 with about a hundred feet of coarse wire wound 
 around its core. The intensity combination opens 
 and closes this quantity circuit, whose armature 
 strikes the sounder, just as the intensity armature 
 itself does on shorter lines. This obvious plan 
 Henry described and exhibited in Princeton to his 
 classes, long before any magnetic telegraph was 
 ever commercially constructed, or the convenience 
 of such an arrangement had resulted from the 
 great length to which the lines are stretched. 
 
 Upon that apparatus there are but four names 
 to be written. Oersted, who discovered the effect 
 of the voltaic current upon the magnetic needle ; 
 Arago, who discovered that the voltaic current 
 could generate magnetism ; Sturgeon, who produced 
 the first electro-magnet; and Henry, who discovered 
 the conditions under which an electro-magnet 
 might be operated at a distance who invented the
 
 52 PROFESSOR HENRY AND THE 
 
 devices by which it could so operate and who 
 applied those devices to an operative telegraph, of 
 the same form and substance as that now in use 
 all over the world. Beyond their discoveries and 
 inventions nothing is essential to the present tele- 
 graph, except that which was of common knowl- 
 edge when those discoveries were completed, and 
 that ordinary mechanical skill which is far below 
 the level either of discovery or invention. 
 This is the record, and so it will stand forever. 
 
 " The moving finger writes ; and having writ, 
 " Moves on : nor all your piety nor wit 
 " Shall lure it back to cancel half a line, 
 " Nor all your tears wash out one word of it." 
 
 Forty years had fled away since as teacher and 
 pupil we first met, and they seemed like a dream 
 that is past, when again we met to part forever 
 in this world. In the chamber where the 
 angel of death hovered over him, just ready to 
 call him away, he talked thankfully of the past, 
 and hopefully of that eternity on whose verge he 
 stood. The vigor of youth and of manhood had 
 been all spent in the service of humanity, and his 
 strength was gone. The pallor of disease had 
 dispelled the delicate hues of health, and time had 
 traced its furrows on his brow. But the unclouded 
 intellect still held its sway, enthroned in that 
 magnificent head on which the snows of many 
 winters had drifted ; and the gentle loving spirit
 
 MAGNETIC TELEGRAPH. 53 
 
 still, as of old, illumined his beautiful face, but 
 with a clearer, warmer light, reflecting the heaven 
 upon which he gazed. For himself he had but 
 one regret that he had not been spared to 
 complete his last great labor, by which he 
 hoped to confer still one more benefit upon hu- 
 manity, by discovering some means affording 
 greater security for mariners on the treacherous 
 coast, when fogs draw down their impenetrable 
 veils over the lights, and the syren's voice fails to 
 pierce the fickle air. 
 
 The faithful servant faithful unto death only 
 mourned that he could not have done more. With 
 the humble spirit of the true Christian, after hav- 
 ing in the estimation of his fellow-men done so 
 much, he, knowing better than others how much 
 was yet to be done, exclaimed "I am an un- 
 profitable servant. " 
 
 Such a life and such a death exalt and glorify 
 humanity; illustrating and indelibly impressing 
 upon our hearts the sublime truth, that man is 
 made in the image of God. 
 
 " Along the smooth and slender wires, the sleepless heralds run, 
 " Fast as the clear and living rays go streaming from the sun; 
 " No peals or flashes, heard or seen, their wondrous flight betray, 
 " And yet their words are quickly felt, in cities far away. 
 
 4 ' Nor summer's heat, nor winter's cold, can check their rapid course ; 
 4 'Unmoved they meet the fierce wind's blast, the rough waves 
 sweeping force.
 
 54 PROFESSOR HENRY. 
 
 " In the long night of rain and wrath, as in the blaze of day, 
 " They rush with news of weal or woe to thousands far away. 
 
 " But faster still .than tidings borne on that electric cord, 
 
 " Rise the pure thoughts of him who loves the Christian's life and 
 
 Lord, 
 
 " Of him who taught, in smiles and tears, with fervent lips to pray, 
 " Maintains high converse, here on earth, with bright worlds far 
 
 away. 
 
 " Aye, though no outward wish is breathed, nor outward answer 
 
 given, 
 
 " The sighing of that humble heart, is known and felt in heaven; 
 1 ' Those long frail wires may bend or break, those viewless heralds 
 
 stay; 
 
 " But faith's last word shall reach the throne of God, though far 
 
 
 away.* 
 
 See Appendix, Note Y.
 
 NOTE A, PAGE 11. 
 
 Life of Faraday, by Bence Jones. London: 
 Vol. II., p 285. 
 
 NOTE B, PAGE 12. 
 
 Faraday's Experimental Eesearches. Vol. I., p. 
 1, and plate. 
 
 NOTE C, PAGE 12. 
 
 A full account of this is in Bence Jones' Life of 
 Faraday, Vol. II., p. 1 to 6. Faraday tried it in 
 1824, '25, and '28, and failed each time; although, 
 since magnetism had been developed from electric- 
 ity, the converse of the problem seemed very 
 feasible. On the 21st of September, 1831, he tried 
 the experiment with an iron ring electro-magnet, 
 constructed according to Henry's invention, using 
 an intensity battery of ten pairs. One-half of the 
 ring was wound with 72 feet of insulated wire; and 
 the other half with about 60 feet, in the circuit of 
 which a galvanometer was placed. When the 
 battery was closed upon the first circuit, the iron 
 ring became magnetic, and a current of electricity 
 was set up, by induction, in the second circuit,
 
 56 APPENDIX. 
 
 and the galvanometer moved. This experiment 
 says his biographer, is " the discovery by which 
 he will be forever known." 
 
 Henry's account of his own discovery exhibits 
 the very same apparatus. He used his electro- 
 magnet, capable of lifting 600 or 700 Ibs., and 
 united its poles by an iron bar or "keeper," firmly 
 fixed, so as to form a complete circuit the same 
 as the iron ring in Faraday's experiment. Around 
 this " keeper" he wound about 30 feet of insulated 
 wire, in many layers, occupying about one inch in 
 the length of the keeper, and placed a galvanom- 
 eter in the circuit of the coil. When the battery 
 circuit was closed and broken on the coil of the 
 magnet, the galvanometer moved, and the great 
 discovery was made (Sillimari's Journal, July, 
 1832). 
 
 Faraday had been working over it for seven 
 years. Henry never touched the question till 1827. 
 
 NOTE D, PAGE 21. 
 
 In another arrangement of this same invention, 
 a heavy wire is laid between the tracks, and large 
 inductive coils, near the floor of the car, are 
 affected by the current in the line wire. Henry 
 exhibited the principle of this apparatus in 
 Princeton, when in the cellar of the Philosophical 
 Hall, induced currents were set up in a wire lead- 
 ing around the apartment, induced by passing a 
 battery current through a similar wire in the 
 upper story, thirty feet above, and with two floors 
 between.
 
 APPENDIX. 57 
 
 NOTE E, PAGE 21. 
 
 This engine is now at Princeton in the labora- 
 tory. 
 
 NOTE F, PAGE 25. 
 
 Since the accession of President McCosh, the 
 donations to Princeton College have been munifi- 
 cent. John r C. Green, Esq., of New York, in his 
 lifetime, and the trustees of his estate since his 
 death, have given princely gifts, amounting to 
 millions. The Green School of Science, with its 
 splendid buildings and complete apparatus, sup- 
 ported by an endowment for its professors; the 
 beautiful library, with an ample fund; Dickenson 
 Hall, containing elegant lecture and class-rooms; 
 Witherspoon Hall, one of the noblest structures 
 in the State, and Edwards' Hall both dormitories 
 for students; and large sums for general purposes, 
 are the permanent monuments of this generosity. 
 
 Henry G. Marquand, Esq., of New York, has 
 erected a beautiful chapel, bearing his name, un- 
 surpassed by any college chapel in this country; 
 and in addition, has endowed a professorship of art. 
 
 Messrs. Robert L. Stewart and Alexander 
 Stewart, brothers, gave to the College during 
 their lifetime the splendid Potter mansion, as a 
 residence for the President. 
 
 Mrs. Robert L. Stewart, of New York, has 
 founded the School of Philosophy, and lately has 
 given $150,000 to establish the chairs in this school 
 thus emulating the example, and equalling the 
 generosity of her deceased husband and brother-in- 
 law to the Theological Seminary at Princeton.
 
 58 APPENDIX. 
 
 The late Mr. Hamilton Murray founded Murray 
 Hall; and John I. Blair, Esq., of New Jersey, has 
 endowed a professor's chair. 
 
 Messrs. Robert Bonner, Robert L. Stewart, and 
 others, presented the magnificent 24-inch aperture 
 telescope, which now, in the hands of the re- 
 nowned astronomer, Professor Young, is doing 
 good work, and is familiarizing students with the 
 mysteries of the universe. 
 
 Physical culture has not been neglected by the 
 Pactolian stream; and Messrs. Robert Bonner and 
 Henry G. Marquand, jointly, have erected one 
 of the most complete gymnasiums in the country. 
 
 Thus our Alma Mater is strengthened and 
 adorned. Let her children, however, not forget 
 that her great present need is scholarships, which 
 are essential to her full development; and that 
 even $100,000 would render an immense service in 
 this most important department. 
 
 NOTE G, PAGE 34. 
 
 " Description of an Electric Telegraph, and some 
 other Electrical Apparatus," by Frances Ronalds. 
 8 vo. London: 1823; also see Nature, London, 
 November 23, 18T1. Vol. 5, p. 59. 
 
 NOTE H, PAGE 34. 
 
 "The Electric Magnetic Telegraph," by Law- 
 rence Turnbull. 8 vo., 2d Ed. Philadelphia: 
 1853, pp. 21, 22. 
 
 Harrison Gray Dyar, an American, set up an 
 electric telegraph in 1827, '28, at the race course
 
 APPENDIX. 59 
 
 on Long Island. Static electricity was used to 
 make a record on a strip of moving litmus paper, 
 and the alphabet was spelled out by the intervals 
 between the sparks passing. /&., 1st Ed., 1852, 
 p. 6. 2d Ed., p. 22. 
 
 NOTE I, PAGE 35. 
 
 " Schweigger's Journal fiirChemieundPhysik." 
 1811. Vol. II., pp. 217, et seq. 
 
 NOTE K, PAGE 35. 
 
 This was Bains' English patent. The same sys- 
 tem has been several times tried here, but with no 
 great success. The Little-Edison " automatic " or 
 "fast line " to Washington some years ago, worked 
 on this plan ; and more recently the Eapid, and the 
 Postal Telegraphs. In all cases, however, an elec- 
 tro-magnetic attachment is needed to give the 
 alarm, and correct the errors. 
 
 NOTE L, PAGE 36. 
 
 Journal of the Society of Arts. July 29, 1859. 
 Vol. VII., pp. 606-7. 
 
 NOTE M, PAGE 36. 
 
 Gottingische Gelehrte. Aug. 9, 1834. Part II., 
 No. 128, pp. 1272-3. 
 
 NOTE N, PAGE 39. 
 
 Faraday had used Henry's quantity magnets in 
 his experiments ; but he does not seem to have 
 considered the effect of the combination of an 
 intensity battery with an intensity magnet, for
 
 60 APPENDIX. 
 
 distant effects ; having probably overlooked Hen- 
 ry's demonstration of that result in Silliman's 
 Journal of 1831. Hence his reference to Wheat- 
 stone. 
 
 The effect of removing the magnet from the 
 battery is stated by Daniells as late as 1843, as an 
 elementary truth. He says: "Electro-magnets 
 of the greatest power, even when the most ener- 
 getic batteries are employed, utterly cease to act 
 when they are connected by considerable lengths 
 of wire with the battery." (Introduction to the 
 Study of Chemical Philosophy ; by Prof. John 
 Frederick Daniell, 2d Ed., 1843, chap. XVI., sec. 
 859, p. 576.) 
 
 NOTE 0, PAGE 39. 
 
 The Electric Telegraph : Was it invented by 
 Professor Wheatstone ? By W. F. Cooke. Part 
 II. 1856. 
 
 NOTE P, PAGE 39. 
 16. Part I., p. 198. 
 
 NOTE Q, PAGE 41. 
 
 Professor Henry made a magnet for Yale Col- 
 legestill there which lifted 2,300 pounds (Silli- 
 man's Journal, April, 1831; Vol. XX., p. 201). His 
 great Princeton Magnet, now in the Scientific De- 
 partment, lifted above 3,000 pounds with a very 
 small battery. 
 
 NOTE E, PAGE 42. 
 Vol. XIX., pp. 403-4.
 
 APPENDIX. 61 
 
 NOTE S, PAGE 43. 
 
 Ingenious men for ages have amused themselves 
 in arranging a bi-signal alphabet to obtain the most 
 simple system. Bacon, in his great work, " On the 
 Dignity and Advancement of Learning,'' Vol. VI., 
 ch. 1, 1605, gives an alphabet of two signs, and 
 says of it : " This contrivance shows a method of 
 expressing and signifying one's mind to any dis- 
 tance, by objects that are either visible or audible, 
 provided the objects are capable of two differences, 
 as bells, speaking trumpets, fire-works and can- 
 non," &c. 
 
 In Rees' Cyclopaedia (1802-19) are given various 
 illustrations of bi-signal and tri-signal alphabets. 
 
 Gauss and Weber's alphabets in 1833, and Stein- 
 heil's in 1836, are very nearly as simple as possible. 
 They use, at most, only four movements, and the 
 most frequent letters are represented by only one. 
 Two and a-half movements to a letter are needed 
 in the best arranged bi-signal alphabet, and these 
 old ones probably would not require more. 
 
 NOTE T, PAGE 43. 
 
 Philosophical Magazine. March, 1832. Vol. XL, 
 p. 199. 
 
 NOTE U, PAGE 45. 
 Smithsonian Report. 1857. Pp. 111-12. 
 
 NOTE V, PAGE 45. 
 
 Steinheil had his telegraph working at Munich, 
 in July, 1837, over twelve miles of line, with eight
 
 APPENDIX. 
 
 stations. It was both a sounding and a printing 
 telegraph, and used the earth as the return circuit. 
 Two bells of different tones gave all the combina- 
 tions needed for the alphabet. (Sturgeon's Annals, 
 April, 1839, Vol. III., p. 520; Comptes Eendus, 
 Vol. VII., pp. 590-93; see also Julius Dup's An- 
 wendung des Elektro-magnetismus, Berlin, 1863, 
 M Ed., 1873, sect. 5, pp. 339-347). 
 
 SteinheiPs telegraph was in fact a galvanometer, 
 in which the needle was made to swing and strike 
 a bell, and to mark a paper by an inking apparatus 
 much like the cable recorder of to-day. It was 
 necessarily weak, and quite inferior to Henry's, of 
 1831, in which any amount of power can be got, 
 and a blow of any strength be delivered. 
 
 NOTE W, PAGE 46. 
 
 In the United States, patents are granted only to 
 inventors ; but in England they are granted to 
 those who "introduce" the inventions into the 
 Kingdom, whether they are inventors or not. The 
 English system, although not founded on so 
 high motives as the United States, is yet pro- 
 ductive of more public good, because it stimulates 
 enterprising men to seek for valuable improve- 
 ments everywhere in the world and introduce them 
 into Great Britain, where, perhaps, their authors 
 would never come, and where, without a patent, 
 no one would be interested in pushing them into 
 use. For a long time, in this country, the tele- 
 graph patent did not repay its owners for intro- 
 ducing it; and no one would have attempted it, or 
 persevered in it, unless in the hope of future
 
 APPENDIX. 63 
 
 reward, which could not have been got unless 
 under the protection of a patent. 
 
 When the Morse patent ran out, he had not 
 been adequately rewarded for the expense and 
 labor incurred in introducing his special arrange- 
 ment into public use, and applied for an extension 
 to the Hon. Charles Mason, then Commissioner of 
 Patents. Mr. Mason consulted Professor Henry 
 on the subject, and he advised the Commissioner 
 to grant the extension, although he had been bit- 
 terly assailed by Morse and his friends in conse- 
 quence of the testimony he had been compelled to 
 give in the lawsuit between the owners of the 
 patent and inf ringers. Professor Henry, although 
 he thought it derogatory to the dignity of science 
 for a scientist to seek for any other reward for his 
 discoveries than the consciousness of having done 
 good to his fellow-men, and the reputation due to 
 his discoveries, yet fully appreciated the wisdom 
 of the constitution and laws on the subject of 
 patents, and thought that without such a system 
 the discoveries of scientists, who devoted them- 
 selves to research, would never be made useful for 
 man in those practical forms in which inventors 
 embody them, and introduce them to the world, 
 often with great labor and sacrifice. 
 
 The subjoined letter of Mr. Mason exhibits the 
 magnanimous character of Henry. In devotion to 
 principle, he recommended an extension of the 
 Morse patent, knowing that to reward amply 
 those who had introduced the invention to the 
 world, would stimulate others to do likewise, al- 
 though in doing it he specially benefited those 
 who had " despitefully used him."
 
 64 APPENDIX. 
 
 " UNITED STATES PATENT OFFICE, j 
 MARCH 31, 1856. J 
 
 "SiR, Agreeably to your request, I now make 
 the following statement : Some two years since, 
 when an application was made for an extension of 
 Professor Morse's patent, I was for some time in 
 doubt as to the propriety of making that exten- 
 sion. Under these circumstances, I consulted 
 with several persons, and among others with 
 yourself, with a view, particularly, to ascertain 
 the amount of invention fairly due to Professor 
 Morse. The result of my inquiries was such as to 
 induce me to grant the extension. I will further 
 say that this was in accordance with your express 
 recommendation, and that I was probably more 
 influenced by this recommendation, and the infor- 
 mation I obtained from you, than by any other 
 circumstance, in coming to that conclusion. 
 
 "I am, sir, 
 
 "Yours very respectfully, 
 
 " CHARLES MASON." 
 "PROF. J. HENRY." 
 
 NOTE X, PAGE 50. 
 
 In reversing the galvanic current on the po- 
 larized relay used by Henry in Albany, and now 
 largely used, the armature is moved both ways by 
 magnetism that is, it strikes the sounder, and is 
 withdrawn from it, by magnetism. When the 
 current is not reversed, but is broken at each 
 signal, magnetism only operates one way, and a
 
 APPENDIX. 65 
 
 spring is used to withdraw the armature from the 
 magnet, where it remains until the next magnetic 
 impulse arrives. 
 
 NOTE Y, PAGE 54. 
 
 These beautiful and now appropriate verses ap- 
 peared in a country newspaper in New Jersey in 
 1848. The figure was so striking, and the versifi- 
 cation so good, that I remembered them; although 
 I regret that the name of their author has escaped 
 me. He was a clergyman, and had a parish in 
 Pennsylvania.
 
 1* 
 
 I1V3- 
 
 I & 
 
 lOSANCElfj-x 
 
 r 
 
 I I 
 
 I 
 
 I * 
 
 
 l^rfii