Few men lived to witness so many remarkable discoveries in science and so many applications of the same to the welfare of the race as did the man whose name stands at the head of this chapter. When William Thomson, the future Lord Kelvin, first saw the light of day, the voltaic pile was in a rudimentary and inefficient form. It is true that water had been decomposed by the current from a pile in 1800,[35] that the magnetic effect of the current had been discovered in 1820, and the possibility of a practical form of an electric telegraph suggested in the same year; but Ohm's law was still one of nature's secrets, electromagnetic induction was undiscovered, and the doctrine of energy but ill understood. Light, electricity and magnetism were regarded as distinct forces, and heat was thought to be a material substance, to which the name caloric was assigned. What Young, Fresnel and AmpÈre were in the early years of the nineteenth century; what Faraday, Regnault and Joseph Henry were some time later, Kelvin became in the 'fifties, a leader in the intellectual and scientific life of the time, a leader destined to extend the frontiers of knowledge, to establish an accurate system of electrical measurement, and to enrich the world with instruments of marvelous ingenuity and precision.William Thomson, born in Belfast in 1824, received his early training in the Royal Academic Institute of that city. When eight years of age, he left his native land, exchanging the shores of Antrim for the banks of the Clyde. His father, James Thomson, a mathematician of note, having been appointed to the chair of mathematics in the University of Glasgow (founded in 1451), proceeded early in the summer of 1832 to the commercial metropolis of Scotland, accompanied by his two sons William and James, both of whom were destined to add lustre to the family name.

After a period of preparatory study, the two brothers, who were ten and eleven years of age, respectively, matriculated at the university. With the iron-clad regulations that govern admission to American colleges and universities, these boys would at best have been admitted to one of our high schools, and kept there until they reached the maturity required by the age limit. By the time young William attained that limit, he had already finished his work at the university, and captured the first prizes in mathematics, astronomy and natural philosophy. He was then only sixteen years of age, small of stature, but a giant in intellect; brilliant, versatile, and with a passion for work. It was his good fortune, also, to come under the influence of a great teacher, in the person of Prof. Nichol. "I have to thank what I heard in the natural philosophy class," he said in 1903, "for all I did in connection with submarine cables. The knowledge of Fourier was my start in the theory of signaling through submarine cables, which occupied a large part of my after-life. The inspiring character of Dr. Nichol's personality and his bright enthusiasm live still in my mental picture of those old days."

Having heard Fourier's treatise on the mathematical theory of heat spoken of one day as a remarkable and inspiring work, young Thomson astonished the Professor when, at the end of the lecture, he addressed Dr. Nichol with the query, "Do you think that I could read it?" To which the Professor smilingly replied: "Well, the mathematical part is very difficult." Many a student would have left Fourier alone for the nonce, after listening to a statement so little calculated to excite courage or awaken interest: but Thomson was not an ordinary student; and, however forbidding the answer which he received, he was determined all the same to handle the volume and seek its inspiration. Without delay, he got the book from the university library, and grew so delighted with the new ideas of the French mathematician about sine-expansions and cosine-expansions, that in the space of two weeks he had "turned over all the pages" of the book, as he modestly put it.

In the summer of 1840, he accompanied his father and his brother on a tour through Germany, partly to see the country and partly also, to acquire a practical knowledge of the language. In both these objects, he was somewhat hindered by his fondness for mathematical studies, which led him to include in his impedimenta for the trip a copy of Fourier's ThÉorie analytique de la Chaleur. Most students out on a summer's vacation, especially in foreign parts, would doubtless have preferred to give their minds rest and congenial distraction rather than keep on reading and pondering over abstract mathematical concepts. Our young tourist, on the other hand, seems to have thought of little else than of Fourier's "mathematical poem," as Clerk Maxwell called the work, a "poem" that continued to have a charm for him all through life. It is a noteworthy fact that Thomson continually returned to the ideas and methods of this suggestive treatise on the flow of heat, and that he applied them with great success to problems in thermal conductivity, in electricity and in submarine telegraphy.

Shortly after returning home, Thomson was sent to the University of Cambridge, where he entered St. Peter's College, commonly called Peterhouse, one of the oldest colleges of the university, its foundation dating back to the year 1284. Though he, no doubt, followed in a general way the directions given him by William Hopkins, "the best of private tutors," and kept in view the requirements of the honors examination, called the "Mathematical Tripos," for which he intended to present himself at the end of his course, he found his studies somewhat routinal and uninspiring. Original work was more to his taste than conventional subjects; his tutor, however, thought mainly of placing this brilliant pupil at the head of the wranglers, and hailing him the senior wrangler of the year, for which purpose, the beaten track must be followed, the standard works read, favorite problems worked out, short-cuts conned and rapidity of output exercised. Stokes, of Pembroke, had been senior wrangler in 1841; Cayley, of Trinity, in 1842; and Adams, of John's, in 1843; why not Thomson, of Peterhouse, in 1845, argued Hopkins, who had the distinction of being second wrangler of the previous year?

But when the ordeal was over and the work of all candidates appraised, Thomson's name was second on the list, with Parkinson, of John's, at the top. Hopkins was disappointed, as he had a right to be, for it was thought by many and said by some that Parkinson was not fit to sharpen Thomson's pencils. At the examination for the Smith's prizes, which immediately followed, and which was generally regarded as a higher honor and a better test of original ability, the order was reversed, and Thomson's star blazed out with the brilliancy of the first magnitude.

We have here an instructive instance of the failure of an examination to place rightly the most gifted man; that of Sylvester, in 1837, and Clerk Maxwell, in 1854, both of whom were second wranglers, are equally so. Examinations, however, seldom fail in justly rating candidates when originality is not a necessary qualification, but only a sound knowledge and liberal interpretation of the subjects laid down in the syllabus; a good memory and rapidity of writing will do the rest.

Thomson committed the fatal mistake in the tripos examination of devoting too much time to a particular question in which he was deeply interested. It was a curious coincidence that the solution which Parkinson sent in to the same question was almost identical with that of his rival for mathematical honors. On being questioned about the matter by the Moderators, Parkinson said that he had read the solution some time before in the Cambridge Mathematical Journal; Thomson's explanation was that the solution given in the Journal was his! As he had not memorized the details, he was obliged of course to work the problem out de novo.

Parkinson in later years wrote a treatise on elementary mechanics that has long since made way for others; Thomson, on the other hand, published in collaboration with Tait a Treatise on Natural Philosophy for advanced students, which became at once the accepted standard. Throughout this treatise, the view is emphasized that physics deals with realities more than with theories, with mutual relations more than with their mathematical expression. Helmholtz thought so highly of this work that he translated it into German, saying in his preface: "William Thomson, one of the most penetrating and ingenious thinkers, deserves the thanks of the scientific world, in that he takes us into the workshop of his thoughts and unravels the guiding threads which have helped him to master and set in order the most resisting and confused material." And again: "Following the example given by Faraday, he avoids as far as possible hypotheses about unknown subjects, and endeavors to express by his mathematical treatment of problems simply the law of observable phenomena."

We are not to think of Thomson, the undergraduate, as of one who gave himself up, mind and body, to his favorite studies; he knew how to combine, in some measure, the dulce with the utile, for he was fond of music, and so proficient in the art that he was elected President of the Musical Society. He also took a practical interest in aquatic sports, and on the Cam he could ply his sculls with the best of the men. Indeed, he was fond of the water all through life, his Lalla Rookh being well known on the Clyde and in the Solent. Expert in the navigation of his yacht, he liked to be out on the deep, caressed by wind and buffeted by wave, on which occasions he usually studied, pencil in hand, problems connected with navigation and hydrodynamics.

Thomson was never without his note-book. Even in his journeys to London, when he usually took the night train to save time, his mind was active, and the green-book was in frequent requisition to receive thoughts that occurred relative to problems that engaged his attention. Unlike many mortals, he was able to sleep soundly on those night trips, although in the early days he had none of the luxuries of traveling which we consider indispensable to our comfort.

Helmholtz records that, being on the Lalla Rookh on one occasion, Thomson "carried the freedom of intercourse so far that he always had a mathematical note-book with him; and as soon as an idea occurred to him, he began to reckon right in the midst of company." This reminds us of the answer which Newton gave to a friend who asked him how he accomplished so much. "By constantly thinking of it," was the brief reply. Concentration of the faculties is necessary for all good work; a distracted mind never achieved anything of value in philosophy, in science, in religious worship. Concentration is like a convex lens, which brings rays to a focus; whereas distraction is like a concave lens, which breaks them up into a number of divergent and scattered elements.

On leaving Cambridge in 1845, Thomson proceeded to London, and was warmly received by Faraday, then of world-wide reputation. He next went to Paris, where, in the laboratory of Regnault, he devoted himself to original research, under the direction of that great and accurate physicist who was then carrying out his classic work on the thermal constants of bodies.

The year 1846 marks an epoch in Thomson's life; for, in that year, he was chosen to succeed Nichol, his friend and master, in the chair of natural philosophy in the University of Glasgow. Though only in his twenty-second year, he chose for the subject of his inaugural address the age of the earth, a subject which continued to have a life-long interest for him because of its very fascination, and perhaps, too, because of the opposition which his views aroused on the part of biologists and geologists. These demanded untold Æons for the original fire-mist to cool down and form a spinning globe fit to be the abode of organic life, whereas Thomson endeavored to show the weakness of the arguments which they advanced to uphold their claim for unlimited time. Basing his estimate on the rate of increase of temperature as we go below the earth's surface, he concluded that the earth required from 100 to 200 million years, and probably less, to cool from its molten state to its present condition.

Impressed by the value of the experimental work which he did under Regnault in Paris, Prof. Thomson gave himself no rest until he secured a place in which the demonstrations of the lecture-room could be supplemented by qualitative and quantitative work in the laboratory. This was the first "physical laboratory" open to students in Great Britain, a fact that makes the year 1846 a memorable one in the history of university development. Two apartments were allotted him for experimental purposes, viz., an abandoned wine-cellar and a disused examination-room, to which, as time went on, were added a corridor, some spare attics, and even the university tower itself, so great was the power of annexation possessed by the young Professor. In those dark and cheerless rooms, a few old instruments were installed, after which students were invited and work begun. A band of men, whose ardor was enkindled by the glowing enthusiasm of the presiding genius, gathered around him, and helped him to carry out investigations on the properties of metals, on moduli of elasticity, elastic fatigue and atmospheric electricity. Among this band of earnest students it will suffice to mention the names of the late Prof. Ayrton, an eminent electrician; Prof. John Perry, known for his Homeric battles in favor of reform in the teaching of mathematics; Sir William Ramsay, the discoverer of the "newer" gases of the atmosphere; and Prof. Andrew Gray, who succeeded his master in the University of Glasgow.

Writing of his laboratory experiences, Prof. Ramsay says: "I remember that my first exercise, which occupied over a week, was to take the kinks out of a bundle of copper wire. Having achieved this with some success, I was placed opposite a quadrant electrometer and made to study its construction and use." "Although this method," he adds, "is not without its disadvantages—for systematic instruction is of much value—there is something to be said for it. On the one hand, too long a course of experimenting on old and well known lines is likely to imbue the young student with the idea that all physics consists in learning the use of apparatus and repeating measurements which have already been made. On the other hand, too early attempts to investigate the unknown are likely to prove fruitless for want of manipulative skill and for want of knowledge of what has already been done."

Prof. Gray wrote: "In the physical laboratory, Prof. Thomson was both inspiring and distracting. He continually thought of new things to be tried, and interrupted the course of work with interpolated experiments which often robbed the previous sequence of operations of their final result."

It may bring a grain of consolation to teachers who meet with troublesome elements in the discharge of their duties, to know that Thomson, great and brilliant as he was, had similar experiences now and again. At one time a book of mathematical data would be removed from the place assigned to it, upon which he would give orders that it should be chained to the table; at others, there would be no chalk near the blackboard, and then the assistant would be solemnly instructed to have one hundred pieces available next time. On one occasion, he settled in a very novel manner the case of a student who insisted on disturbing the class by moving his foot back and forth on the floor. Calling his assistant, Thomson told him in a whisper to go down into the room under the tiers of seats, to listen attentively, and locate the wandering foot by its distance from two adjacent walls of the building. On his return to the lecture-room, the triumphant assistant gave the desired coordinates to the Professor, who took out his tape at once and measured off the distances, by which the outwitted offender was mathematically located. In obedience to orders, the latter rose and left the room, muttering a few graceful epithets as he went, in honor of Descartes, the founder of a system of geometry that could serve so well the twofold purpose of the detective and the mathematician.

It was the custom in Glasgow to open the daily sessions, morning and afternoon, with prayer, the selection of which was left to the discretion of the Professor. Thomson usually recited from memory the third collect from the morning service of the Church of England, to which he sometimes added reflections of his own for the spiritual benefit of his hearers.

In his teaching, Prof. Thomson was particularly insistent that his students should not bow their intellects in mute admiration before an array of mathematical symbols; but that, on all occasions, they should seek the physical meaning behind them. Writing on his blackboard one day dx/dt, he was not satisfied when told that it represented the ratio of the increment of x to the increment of the independent variable t (time); he wanted the student to say it represents velocity. He himself was so wont to look for the physical meaning of symbols that, like the prophets of old, he saw many things that were hidden from the eyes of ordinary mortals.

He had the rare gift of translating mathematical equations into real facts; and he strove all throughout his life, by word and writing, to purify mathematical theory from mere assumptions. He often said that he could not understand a thing until he was able to make, or at least conceive, a model of it.

He had a "keen mathematical instinct," as Prof. Silvanus P. Thomson puts it in a letter to the writer, an insight that "grew to see things." He often left matters in the dark for years, then returned to see them in the clear light of truth. At the age of sixteen, he wrote a mathematical essay on the figure of the earth; and at eighty-three, took it up again in order to add a note to the argument!

Thomson was discursive in his lectures, and was never able to boil the matter down to suit the taste and digestive powers of the ordinary student. The activity of his mind and its fecundity were such that new ideas, new problems, new modes of treatment were continually occurring, and with such fascination that he would leave the main subject to indulge in what often proved prolonged digressions. One of his bugbears was our system of weights and measures, which he denounced in season and out of season as "insane," "brain-wasting" and "dangerous." Occasionally epithets of a more caloric nature would escape the lips of the indignant Professor, who, as a consequence of his denunciation, had always to be indulgent to students who chanced to be shaky in the matter of Troy weight, avoirdupois weight or even apothecaries weight.

In later years, I heard Lord Kelvin at the Royal Institution, London, on some of his favorite dynamical subjects, such as the gyrostat, vortex rings and the like. However impressed by his keen eye, intellectual forehead, his mastery of the subject and wealth of illustration, I was no less impressed by his vivacity, his enthusiasm and the rapidity with which he could leave a train of thought and return to it again.

At meetings of the British Association, he always had something illuminating to say; but not infrequently, carried away by a torrent of ideas, he would indulge in a superfluity of detail, forgetting that other speakers had to be heard and other papers read.

The idea of connecting the Old World with the New by means of an electric cable laid on the bed of the ocean, seemed to most people in the 'fifties quixotic and utopian. Manufacturers said such a cable could not be made; engineers, that it could not be laid; electricians, that it could not be worked; and financiers, that if laid and worked, it would never pay. But with a Field to look after the financial interests of the scheme, and a Thomson to attend to electrical quantities, there was no tilting at windmills, and the utopian scheme became in due time the cable whose core pulsated with the news of the world.

As early as 1850, Bishop Mullock, of St. John's, N. F., addressed to an American newspaper, called the Courier, a letter in which he advocated a telegraph line from Newfoundland to New York, so that the news of mail steamers could be intercepted and wired to that City. In 1852, the "Newfoundland Electric Telegraph Company" was formed for the purpose of carrying out a similar plan. This was to be accomplished by means of a telegraph line from Cape Race, at the eastern extremity of Newfoundland to Cape Ray, on the western, as well as by short cables over to Cape Breton Island, to Prince Edward Island and the mainland, and thence by ordinary telegraph lines to Canada and the United States. But owing to the want of money, nothing was done.

The first attempt at laying a cable under the Atlantic was made by the Atlantic Telegraph Company in 1857, after a careful survey of the ocean had revealed the existence of a submarine plain, or extended table-land, on which the cable could rest undisturbed by passing keels, monsters of the deep or angry billows. The result was the first of a series of failures, which caused great perplexity and depression at the time; for, after 330 miles had been paid out from Valentia on the Irish coast, the cable suddenly parted, burying in 2000 fathoms of water an electrical conductor which had cost $150,000 for its manufacture.

A second attempt was made in 1858, when the U. S. frigate Niagara and H. M. S. Agamemnon, each carrying half of the cable, met in mid-ocean; and, after splicing the two ends together, steamed away in opposite directions, the Niagara toward Newfoundland and the Agamemnon toward Valentia. Fortunately for the enterprise, Prof. Thomson was on board the English ship as chief electrician. No doubt, his mind turned many a time during those anxious days to Fourier's differential equation for the flow of heat along a conductor, and his own application of it to the conduction of the electric current through the copper core of the cable as it came up from the tanks, trailed out behind the ship, dipped silently into the blue water and slowly settled down to its bed of ooze on the ocean floor.

After a series of disheartening mishaps, necessitating as many returns of the ships to the rendezvous in mid-ocean, the Agamemnon landed the shore-end safely in Valentia; and the Niagara, after rolling and pitching for days and nights in tempestuous seas, landed hers in Trinity Bay on the morning of August 5th, 1858, on which historic date the telegraphic union of the two worlds was finally consummated and the great feat of the century accomplished.

Though not fully realized at the time by the capitalists who financed his scheme, by the engineers and electricians who carried it out, or even by statesmen, economists and social reformers, the slender copper cord, buried away from human ken amidst the dÉbris of minute organisms, was destined to effect a revolution in the affairs of men greater than any achieved by the wisdom of sages or the policy of legislators.

Owing to the electrostatic capacity of the cable, signaling would have been difficult and unsatisfactory had it not been for the resourcefulness of Prof. Thomson, who devised his reflecting galvanometer to serve as receiving instrument. The principle of the mirror applied in this way was not new, for it had been suggested by Poggendorff and even used by Gauss in connection with very heavy magnets. The magnets used by Thomson, on the other hand, were strips of watch-spring weighing about a grain each, so that even a very weak current coming through the cable would be sufficient to produce strong displacements of the spot of light on the scale. Thomson was clearly the first to insist on small dimensions in magnetic instruments, and to show that reduction in size would be attended with corresponding increase in sensitiveness.

The mirror galvanometer, surrounded with a thick iron case to screen it from the magnetic field due to the iron of the ship, the "iron-clad galvanometer" as it was called, was used for the first time on the telegraphic expedition of 1858.

The instrument itself, which was fitted up on board the Niagara and which was connected with so many episodes of thrilling interest, was placed by Prof. Thomson in the collection of historical apparatus in the University of Glasgow, where it is at the present day.

Beautiful as was the invention of the mirror galvanometer, it gave neither warning of the beginning of a message nor a permanent record of it. Sitting in his dark room, the operator had to be always on the alert for the first swing of the spot of light over the scale. To obviate these drawbacks, Thomson, after some thinking and more talking with his friend White, of Glasgow, finally patented the siphon-recorder, in which a glass siphon of capillary dimensions is pulled to the right or left by the action of the current flowing through a light movable coil, and is thus made to register signals in ink on a vertical strip of paper which is kept in uniform motion by a train of clockwork. It is by this simple but very ingenious instrument that messages are received and recorded to-day at all the cable-stations of the world.

The inaugural message through the cable came from the Directors of the Atlantic Telegraph Company in Great Britain to the Directors in America, saying: "Europe and America are united by telegraph; glory to God in the highest, on earth peace and good will toward men."

The message from Queen Victoria to President Buchanan, consisting of 95 words, took 67 minutes in transmission; it read:

"The Queen desires to congratulate the President upon the successful completion of this great international work, in which the Queen has taken the deepest interest.

"The Queen is convinced that the President will join with her in fervently hoping that the electric cable which now connects Great Britain with the United States will prove an additional link between the nations whose friendship is founded upon their common interests and reciprocal esteem.

"The Queen has much pleasure in thus communicating with the President, and renewing to him her wishes for the prosperity of the United States."

The reply of President Buchanan was as follows:

"The President cordially reciprocates the congratulations of Her Majesty, the Queen, on the success of the great international enterprise accomplished by the science, skill and indomitable energy of the two countries. It is a triumph more glorious, because far more useful to mankind, than was ever won by conqueror on the field of battle.

"May the Atlantic telegraph, under the blessing of Heaven, prove to be a bond of perpetual peace and friendship between the kindred nations, and an instrument destined by Divine Providence to diffuse religion, civilization, liberty and law throughout the world. In this view will not all nations of Christendom spontaneously unite in the declaration that it shall be forever neutral, and that its communications shall be held sacred in passing to their places of destination, even in the midst of hostilities?"

The historian of the enterprise was Mr. John Mullaly, of New York, who was on the Niagara as secretary to Prof. Morse and subsequently to Mr. Cyrus W. Field and correspondent of the New York Herald. He has published three interesting works on the subject: a Trip to Newfoundland, with an account of the laying of the submarine Cable (between Port au Basque and North Sydney), 1855; The Ocean Telegraph, 1858; and The first Atlantic Telegraph Cable, a pamphlet of 28 pages, reprinted from the "Journal of the Franklin Institute," 1907. From it, we learn that Archbishop Hughes was one of the principal American subscribers to the capital of the Atlantic Cable Company.

When, in 1855, the subject of laying a cable under the Atlantic ocean began to be seriously considered, Thomson, who was then only 31 years of age, discussed in a series of masterly papers the theory of signaling through such conductors, showing inter alia that the instruments used on land-lines would be inoperative on cables, and also that the same speed of transmission could not be attained on cables as on ordinary telegraph lines. It was shown at the same time, that these differences are due to the fact that, unlike an air-line, the cable is an electrical condenser in which the copper core is separated from the waters of the ocean by a layer of gutta percha, a nonconducting material. As a submerged cable is, therefore, a long Leyden jar of great electrical capacity, it follows that a signal sent in at the American end will not reach the other instantly; for while the current flows along the conductor, it has also to charge up the cable as it progresses, which operation retards the signals, and also deprives them of the clearness and sharpness with which they were sent. The phenomenon is analogous to the diffusion of heat along a bar, the temperature of the various cross-sections rising in gradual succession until the distant end is reached. The mathematical investigations of Thomson showed the necessity of working slowly, and of using weak currents as well as very delicate receiving instruments. The interval of time required for the transmission of a signal from Newfoundland to Valentia is about one second.

Some years later, in 1858, Thomson had the opportunity of putting his theoretical views to the test of experiment on a grand, commercial scale, and had the satisfaction of finding that all his conclusions were confirmed. Electricians of the early period distrusted the inexperienced young man who had never erected a mile of telegraph line or even served for a month in a telegraph office; but their distrust was followed by admiration when they saw the efficient manner in which he handled every problem and dealt with every difficulty that occurred while laying the cable of 1858. It was generally admitted that, had it not been for the brilliant work of the young Glasgow Professor, many years would have passed away before the Old World and the New would have been brought into telegraphic communication.

Like all interested in the enterprise, Thomson was greatly shocked when the news reached him that signals could no longer be transmitted through the cable, which, after costing so much money, so much thought and labor, now lay a useless thing in two and a half miles of water. Attempts were made to raise it, but without success.

During its short life of less than a month, 366 messages were flashed through the cable, aggregating 4359 words of 21,421 letters.

The failure of the pioneer cable has been attributed to a variety of causes, chief of which were defective construction and imperfect paying-out machinery, which produced unequal strains in the cable. Defective as the cable was at the moment of immersion, the various troubles became intensified with time, until at last, when provoked by the feebleness of the signals, the injudicious electrician at Valentia had recourse to the great penetrative power of the induction coil, and gave the dying cable the coup de grÂce.

An experiment made by Mr. Latimer Clark is not only germane to the subject, but is also of very great interest. Writing from Valentia on Sept. 12th, 1866, Mr. Latimer Clark says: "With a single galvanic cell, composed of a few drops of acid in a silver thimble[36] and a fragment of zinc, weighing a grain or two, conversation may easily, though slowly, be carried on through one of the cables (1865, 1866) or through the two joined together at Newfoundland; and although in the latter case, the spark, twice traversing the breadth of the Atlantic, has to pass through 3700 miles of cable, its effects at the receiving end are visible in the galvanometer in a little more than a second after contact is made with the battery. The deflections are not of a dubious character, but full and long, the spot of light traversing freely a space of 12 in. or 13 in. on the scale; and it is manifest that a battery many times smaller would suffice to produce similar effects."

Not to be outdone by the English electrician, Mr. William Dickerson devised the gun-cap cell, which he used in 1866 with success in transmitting signals from Heart's Content, Newfoundland, to Valentia on the Irish coast.

A piece of No. 16 bare copper wire was procured, one end of which was firmly twisted around the head of an empty percussion-cap. To one end of another similar length of wire was bound, with fine copper wire, a short strip of zinc bent at a right angle to form the anode element of the diminutive cell. After charging the cell with a drop of acidulated water of the size of an ordinary well-formed tear, and properly connecting the terminals with earth and cable, signals were transmitted over the cable by the infinitesimal current generated by this novel cell. The receiving operator reported that the signals were "awfully small"; but they were intelligible, and messages were successfully transmitted under the ocean by this tiny element.

Contrast with this Lilliputian cell the enormous power that was used on the cable of 1858 toward the end of its short existence, when batteries of 380 and 420 Daniell cells were employed to force signals across.When, in 1865, it was decided to make another attempt at laying a cable under the Atlantic, Prof. Thomson, whose reputation was enhanced during the seven intervening years by a number of communications on the theory and practice of submarine telegraphy, was again retained as scientific expert in a consultative sense, with Mr. Cromwell F. Varley as chief electrician. In accordance with the costly experience that had been gained, a new cable was made and coiled on board the Great Eastern,[37] a leviathan which was well fitted for the work by the great manoeuvring power afforded by its screw and paddles combined. Leaving Valentia, the big ship steamed with her prow to the west at a slow rate of speed, in order to give the cable time to sink beneath the waves and adapt itself to the configuration of the ocean floor. Eleven hundred miles had been successfully paid out when, to the consternation of all, the cable suddenly snapped and disappeared in more than two miles of water. Attempts were made during the next nine days to recover it from those abysmal depths; and, though grappled many times during those trying hours, it gave way each time under the strain to which it was subjected. Like its predecessors of 1857 and 1858, the cable of 1865 was finally abandoned to its fate, and the Great Eastern returned home with three greatly disappointed men on board, viz., Prof. Thomson, Mr. C. F. Varley and Captain (later Sir James) Anderson.

In the following year, a sum of three-quarters of a million sterling, nearly $4,000,000, was offered to the Directors of the "Telegraph Construction Company" if they would complete the cable of 1865 and lay a new one. After consultation and careful consideration, the offer was accepted and the cable constructed according to the best engineering knowledge available.

In 1866, Prof. Thomson was again on board the Great Eastern with Captain Anderson; and this time the big ship had snugly coiled up in her deep, cavernous tanks the cable that was destined to put Europe and America in permanent telegraphic communication. With a well-manufactured cable, improved paying-out machinery and an experienced staff of mechanical engineers, not to mention the foremost electricians of the day, the immersion of the cable was successfully effected, after which the American end of the cable of 1865 was raised, a new length spliced on, and the shore-end safely landed in Trinity Bay. Europe and America were thus united together by two electric bonds.

It may here be mentioned that ocean cables are usually made in three sections, called, respectively, the shore-end, the intermediate section and the deep-sea section. It is clear that the submerged conductor needs the greatest protection in the shallow water that surrounds the coast, where it lies on a pebbly or rocky bottom, exposed to the drifting action of currents and tides, as well as to the haling flukes of the anchors of storm-tossed ships. In deep water, on the other hand, there is neither shingly bottom nor violent movement to displace and abrade the cable; for all is quiet and peaceful in the profound depths where the god of the trident holds his court; and hence few coverings and a light armor afford sufficient protection. The wear and tear in the ocean depths is a vanishing quantity when compared with the abrasive effects near coast-lines. Looking at the sections of an ocean cable, the biggest and heaviest is the shore-end, while the thinnest and lightest is that which goes down into the depths of the sea. The lengths of the various sections are determined by the survey of the route, which is always carefully made before completing the specification of the cable. Moreover, as the position of the cable-ship at noon every day is known from its longitude and latitude, it follows that the location of the cable on the bed of the ocean is also exactly known. When a cable is broken either by an upheaval or by a subsidence of the ocean floor, the distance of the rupture from the shore end is determined by an electrical test, after which a repair-ship is dispatched to the spot, when the cable is lifted, the "fault" cut away, a new length spliced on, and the amended cable allowed to settle down into its watery depths.

At the present time (July, 1909), there are sixteen cables carrying the work of the North Atlantic, at an average speed of 20 words a minute duplex, or 40 words a minute, counting both directions.

This cable narrative affords as striking an illustration of the triumph of failure as any recorded in the history of human enterprise. It was a victory of mind over matter; of character and tactfulness, energy and endurance over difficulties of every kind, moral and financial, mechanical and meteorological. The four expeditions of 1857, 1858, 1865 and 1866 represent years of hard work, anxiety and distressing failures; but, sustained by the patience of hope and by an unshaken confidence in the soundness of the enterprise as well as in the ability of their staff, the Directors of the Atlantic Company were well rewarded for the disappointment occasioned and the monetary losses incurred. "It has been a long struggle," said the initial promoter of the enterprise, Mr. Cyrus W. Field, speaking at a banquet given in his honor on November 15th, 1866, at the Metropolitan Hotel, New York, "a long struggle of nearly thirteen years of anxious watching and ceaseless toil. Often my heart was ready to sink. Many times, when wandering in the forests of Newfoundland in pelting rain, or on the decks of ships in dark, stormy nights, I almost accused myself of madness and folly to sacrifice the peace of my family for what might have proved but a dream. I have seen my companions, one after another, fall by my side, and I feared that I, too, might not live to see the end. And yet one hope has led me on; I prayed that I might not taste of death till the work was accomplished. That prayer has been answered; and now, beyond all acknowledgments to men, is the feeling of gratitude to Almighty God."

It was men like Field and Thomson that the poet had in mind when he wrote:

Shortly after his return home, Prof. Thomson was knighted for his splendid services in connection with sub-oceanic cables, and was also honored with the freedom of the City of Glasgow.

If while journeying over land or sea, Sir William's mind was always active, his eyes were also open and observant. In the numerous voyages which he undertook in the interest of cable companies, he seems to have been struck by the unreliable character of the ordinary apparatus used in taking soundings, consisting of a heavy weight suspended by a thick hempen cord unwound from a reel. Owing to the massiveness of the cord, the motion of the ship and currents in the water would necessarily deflect it from the vertical, so that the soundings recorded would be in excess of the true depth. To remedy this defect, Thomson replaced the rope, at first by a steel wire, and later by a thin strand of steel wires, on which the speed of the ship has but little effect; the sinker descends vertically with considerable velocity, and is raised with equal rapidity by suitable winding-up machinery placed in the stern of the ship. The sinker carries a gauge consisting of a quill-tube open at the lower end and closed at the top. The inside, which is coated with silver chromate, shows by the discoloration produced by the action of the sea water how far the water has compressed the air in the tube. By comparison with a graduated ruler, the depth is then read off. When the sinker reaches bottom, the heavy weight is detached automatically, so that there is but little strain on the wire as it ascends with its thermometer and battery of tubes containing samples of the depths reached.

A story is told in connection with this sounding-machine which shows the vivacity and wit of the inventor. Having brought his friend Joule into White's one day, he pointed to a number of coils of steel wire lying on the floor, informing his English friend of "mechanical-equivalent" fame at the same time that he intended the wire for sounding purposes. Upon Joule's innocently asking what note it would sound, he received the prompt answer, "the deep sea"!

Another subject to which Sir William gave some attention after his experiences on the ocean is the navigating compass. His observations led him to distrust the long, heavy needles then in general use on shipboard. Besides the friction to which the pressure on the pivot gives rise and which necessarily diminishes the sensitiveness of the needle, there was another objection, due to the difficulty experienced in successfully applying steel magnets and soft-iron masses to compensate for the magnetism of the ship and for the changes induced in it by change of place in the earth's magnetic field.

As a result, Prof. Thomson devised a compass-card which is remarkable for its lightness and sensitiveness. It is made of two sets of magnets, containing four needles each, arranged symmetrically on the right and left of the pivot. The four needles, forming a set, are of unequal length, ranging from 3-1/4 to 2 inches, with the shortest outermost. Such a card, with its associated correctors of steel magnets and soft-iron balls, has added greatly to the safety and certainty of navigation; and as such, it is used to-day in the merchant service and in the navies of most countries of the world.

As we have seen, Thomson had the keen, racy wit of his race. Lecturing before the members of the Birmingham and Midland Institute in 1883, he placed himself and his nationality on record in a very humorous way. His subject was "The six gateways of Knowledge." As will be remembered by the readers of The Pilgrim's Progress, old Bunyan likened the soul to a citadel on a hill having no means of communication with the outer world save by live gates, viz., the eye gate, the ear gate, the mouth gate, the nose gate and the feel gate. These are the five senses by which we obtain our knowledge of the material world which surrounds us. But Prof. Thomson took issue with Bunyan, with Reid, and the metaphysicians of all time in maintaining in this lecture that we have six gateways of knowledge instead of five, justifying the position which he took by affirming that the sense of touch is really twofold, one of heat and the other of force. It does not appear, however, that he made any marked impression on the philosophic thought of the day, for psychologists continued to write with undisturbed equanimity of the five senses and not the six.

It was on this occasion that Prof. Thomson said: "The only census of the senses, so far as I am aware, that ever before made them more than five was the Irishman's reckoning of seven senses. I presume the Irishman's seventh sense was common sense; and I believe that the possession of that virtue by my countrymen, I speak as an Irishman, I say the large possession of the seventh sense which I believe Irishmen have, will do more to alleviate the woes of Ireland than the removal of 'the melancholy ocean' which surrounds its shores."

For the successful operation of cables, telegraph lines and scientific investigations of all sorts, a system of practical electrical units, accepted by all companies and countries of the world, was soon found to be indispensable. The pioneer in the movement for establishing an international system of electrical standards was Mr. J. Latimer Clark, who, assisted by his distinguished partner, (Sir) Charles Bright, prepared a paper on "The formation of Standards of Electrical Quantity and Resistance," which was read at the Manchester meeting of the British Association in 1861. Prof. Thomson was present; and, at his instance, a committee was appointed to report on the general question of electrical units. This was the first meeting of a committee that was destined to accomplish much in the electric and electromagnetic field; it was the initial impulse of a movement that brought renown to the entire body of English electricians. Such units as the ohm, the volt and the farad met with immediate acceptance, while later on the ampere, the coulomb, the watt and the joule were introduced. Among the members of this body besides Prof. Thomson, were such able men as Clerk Maxwell, Joule, Lord Rayleigh, Sir William Siemens, Johnstone Stoney, Balfour Stewart, and Carey Foster.

The world is then indebted to the insistence and advocacy of Prof. Thomson for the general acceptance of the "C.G.S." system of measurement, which involves the centimeter (length), the gram (mass), and the second (time) as the fundamental units from which all others are derived.

Prof. Thomson has claims in the "wireless" field also; for as far back as 1855, he studied the nature of the discharge of a condenser and proved mathematically that, under certain conditions easily realized in practice, such discharges are of an oscillatory character, consisting of a forward and a backward rush of electricity between the two coatings of the condenser. As pointed out on page 92, Prof. Henry had reached the same conclusion in 1842, and Helmholtz in 1847; but Thomson's insight into the phenomenon is keen and his mathematical analysis of it very remarkable.

Just as the to-and-fro motions of the prongs of a tuning-fork give rise to sound-waves in the air, so the electric oscillation due to a condenser discharge sets up in the universal ether electric waves which flash the news of the world over continents and oceans with unthinkable velocity.By special request, Sir William Thomson gave, in 1884, a course of lectures at the Johns Hopkins University, Baltimore, to an audience of "professional fellow-students in physical science," as he called the Élite of American men of science, twenty-one in number, assembled to hear him. These accomplished physicists he also affectionately called his "twenty-one coefficients."

The subject was the wave-theory of light, and the object of the lecturer was to show how far the phenomena of light, such as its transmission, refraction and dispersion, could be explained within the limits of the elastic solid theory of the ether, which makes that hypothetical medium rigid, highly elastic and non-gravitational. From the very first lecture, Sir William assumed a cold and diffident attitude toward the rival theory of Clerk Maxwell, which makes light an electromagnetic phenomenon; and though his own presented formidable difficulties, and its rival was universally accepted, the veteran Professor assured his hearers that the elastic solid theory is the "only tenable foundation for the wave-theory of light in the present (1884) state of our knowledge."

Despite the energy which he displayed, his luminous argumentation and close logic, Kelvin made no converts among his "twenty-one coefficients"; and it soon became evident that he was championing a lost cause. Newton did the same when he held tenaciously to the corpuscular theory of light; and in doing so, let it be said, that he retarded the acceptance of the wave-theory and the advance of science by a hundred years.

A few years after the Baltimore lectures, official recognition of his distinguished services and of his eminence in science came to Sir William Thomson when, in 1892, he was raised to the peerage, with the title of Baron Kelvin of Netherhall, Kelvin being the name of a stream which passes near the buildings of the University of Glasgow and flows into the Clyde, while Netherhall is that of his country-seat at Largs, in Ayrshire, 40 miles from Glasgow.

As to the structure of matter, Kelvin lived to see the "atom" of his youth and mature years shattered into fragments, and the atomic theory of matter rapidly yielding to the electronic. Though he maintained an open mind toward the new school of physics, he was reserved and conservative toward the revolutionary doctrine of extreme radio-activists. He did not believe in the transformation of one elementary form of matter into another; and he strenuously combated the theory of the spontaneous disintegration of the atom.

Notwithstanding a long life devoted to the study of mathematical and experimental physics, during which Kelvin unraveled many a difficult problem in electricity and magnetism and added many a beautiful skein to the texture of our knowledge in electrostatics and electrokinetics, that illustrious man, the acknowledged leader in physical science, made a public admission in 1896 which caused a great stir throughout the scientific world. It was on the occasion of the celebration of the golden jubilee of his professorship of natural philosophy in the University of Glasgow. Delegates had come from all parts of the world; kings and princes had sent their representatives; universities and learned societies of every country of the Old World and the New vied with one another in doing honor to the scientist who had figured so long and so conspicuously in the advances of the age. It was on that solemn occasion and in presence of such a notable assembly that Kelvin made the astonishing admission that, although he had been a diligent student of electricity and magnetism for a period exceeding fifty years, and although he had pondered every day for forty years over the nature of the ether and the constitution of matter, he knew no more about their essence, about what they really are, than he knew at the beginning of his professional work.

This confession, remarkable by reason of the man who made it and the circumstances in which it was made, has always appeared to the writer of these lines as having more of the ring of disappointment in it than of blank failure. Kelvin's great analytical mind early and persistently strove to penetrate the closely guarded secrets of nature; and because Dame Nature did not yield to his open sesame, but persisted in her reticence, the philosopher grew pessimistic and disappointed; and, under the sway of such feelings, he summed up the result of his life-quest after the ultimate problems in science and pronounced it a "failure."

A "failure" it was not, if science is the discovery and registration of the laws of God as revealed in the universe of mind and matter; for few men of his generation, if any, made more contributions of the first order to the theory of electrostatics, to the doctrine of energy, to hydrodynamics and the thermo-electric properties of matter. This note of disappointment, or wail of despondency, had been sounded before by Faraday, who said that, the more he studied electrical phenomena, the less he seemed to know about electricity itself. Was not Laplace animated by a kindred feeling when he spoke about the infinitude of our ignorance? Lastly, was not this intense feeling of our limited powers precisely that which, after all his discoveries in mathematics, in optics and in celestial mechanics, made Newton compare himself to a child standing on the beach with the vast ocean of truth before him, unfathomed and unexplored?

Kelvin gave a beautiful example to the world when, after resigning the chair which he had occupied for fifty-five years in the University of Glasgow, he immediately proceeded to enter his name on the undergraduate list, intimating by such an act that, whether a man is a professor-in-ordinary of natural philosophy or a professor emeritus, he must ever be a student, in close touch with nature.

Lord Kelvin had the happiness of enjoying good health throughout all the years of his long career, a happiness due in part to nature, and in part also to the simplicity, frugality and regularity of his life.

As already said, he was fond of cruising in European waters in his yacht Lalla Rookh during the summer months, and even venturing out on the Atlantic as far as Madeira, for,

In later years, however, owing to facial neuralgia, he was accustomed to spend a month or so every summer with Lady Kelvin at Aix-les-Bains, from which visits he always derived much benefit.

While making some experiments in a corridor of his beautiful home at Netherhall, he caught a chill on November 23d, 1907, from which he never rallied, despite the cares and attentions that were fondly lavished upon him. The bulletins that were issued concerning his condition were read all the world over with more concern than if they referred to a reigning sovereign or an heir apparent. Every teacher of physics, mathematical or experimental; every man interested in the advance of science and the spread of knowledge, anxiously awaited news from the sick-room of the illustrious patient—news that was transmitted to the ends of the earth by the siphon-recorder invented by the dying scientist in the heyday of his life; and when the word came that Kelvin had breathed his last, that cablegram brought universal sorrow for the quenching of the brightest light of the age and the loss of the leading scientist, the model man and faithful Christian.

It was in the fitness of things that the man who was considered the greatest since Newton should be buried in Westminster Abbey, and that the mortal remains of Lord Kelvin should find a resting-place next to the grave of the genius who thought out the Principia and discovered the gravitational law which governs the planetary as well as the stellar universe.

If asked to say what impressed me most in Lord Kelvin, I would mention the cordial manner in which he welcomed those who sought advice; the encouragement which he held out to students; his absolute devotion to truth; his fair-mindedness and candor; his reverence in dealing with the problems of the soul and the destiny of man; and the uniform, tranquil happiness of his life, due, under God, to his profound religious belief and noble Christian life.

A man of strong convictions, Kelvin did not, however, wear his religion on his sleeve, but treasured it in the depths of his heart, where it was never disturbed by the tossing and ever-changing wave-forms of individual opinion. He quietly but uniformly maintained that physical science demands the existence and action of creative power; and he did not shrink from affirming this conviction whenever circumstances seemed to require it, as was the case on the memorable occasion of his Presidential address to the members of the British Association in 1871. In concluding that brilliant discourse, he said: "But strong, overpowering proofs of intelligent and benevolent design lie all around us; and if ever perplexities, whether metaphysical or scientific, turn us away from them for a time, they come back upon us with irresistible force, showing to us, through nature, the influence of free will, and teaching us that all living beings depend on one ever-acting Creator and Ruler."

Once when particularly disgusted with the materialistic views of those who, while denying the existence of a Creator, attributed the wonders of nature, animate and inanimate, to the potency of a fortuitous concourse of atoms, he wrote to Liebig, asking him if a leaf or a flower could be formed or even made grow by chemical forces, to which he received the significant reply from the famous chemist of Giessen: "I would more readily believe that a book on chemistry or on botany could grow out of dead matter by chemical processes."

We have already referred to the custom which obtained in the University of Glasgow, of beginning the daily sessions by invoking the blessing of heaven on the work about to be undertaken. Having liberty in the matter of choice, Prof. Thomson selected for this purpose a prayer from the morning service of the Church of England, which reads: "O Lord, our heavenly Father, almighty and everlasting God, who hast safely brought us to the beginning of this day; defend us in the same with Thy mighty power; and grant that this day we fall into no sin, neither run into any kind of danger; but that all our doings may be ordered by Thy governance, to do always what is righteous in Thy sight; through Jesus Christ, our Lord, Amen."

Academical honors were showered upon Lord Kelvin by seats of learning, ancient and modern; he was a D. C. L. Oxford, LL. D. Cambridge, and a D. Sc. London; he was President of the Royal Society from 1890 to 1895; President of the British Association in 1871; Knight of the Prussian Order Pour le MÉrite, and Foreign Associate of the Institut de France.

His published works include a "Treatise on Natural Philosophy," 2 vols., written in collaboration with Prof. Tait, of Edinburgh (the two authors were often referred to as T and T'); "Contributions to Electrostatics and Magnetism"; "Collected mathematical and physical Papers," 3 vols.; "Popular Lectures and Addresses," 3 vols.; and the "Baltimore Lectures." These, as well as the instruments which he devised for navigation, for the finest work of the laboratory, as well as for the commercial measurement of current, potential, and energy, form a monument to Lord Kelvin that will be aere perennius.

Brother Potamian.