On August 23, 1850, a small boat trailing an unwieldy black rope from its stern sailed clumsily across the English Channel from Dover to Calais. With lead weights attached every 100 yards, the rope sank the 30 feet or so to the seabed. When the boat reached the French coast, the end of the rope was attached to a wooden box equipped with brass knobs and a dial bearing the letters of the alphabet. At Dover the man running this curious operation, John Brett, attached similar equipment to the other end. After fiddling with the device for a while, he reported that signals were now traveling back and forth across the channel, and he produced slips of paper on which printed letters could be seen. Locals who had gathered on the beach were skeptical. Some “expressed their great astonishment, and inquired if paper and print had all made its transit by the wire.” Others scoffed, imagining the rope as a sort of immense underwater bell-pull. “What a mad scheme!” someone said. “Why a sailor, or anyone who knew anything about seafaring matters, would declare it was impossible to pull such a line 25 yards, let alone that number of miles, over such a rough and uneven surface as the bottom of the channel.”

Brett proclaimed, as only a true Englishman could, that this communication across 21 miles of shallow water represented the first telegraphic

link “from one continent to another.” The rope was, of course, an electrical cable, of exceedingly amateur design. Hundred-yard lengths of copper had been wrapped in strips of gutta percha, a gummy tree sap discovered a few years earlier in Malaysia. Michael Faraday, given some samples of gutta percha in 1848, had sent a short note to the Philosophical Magazine recounting the material’s excellent qualities for the laboratory electrician. It was soft and moldable when warm, resilient yet still flexible when cold, and made a good electrical insulator. Faraday used it for plugs and supports and insulating sheets in his various experiments. It also resisted water, which is why Brett had chosen it to insulate his underwater telegraph cable. To assemble the hundred-yard lengths into 25 miles of cable, the exposed ends of the copper wires were twisted together, and globs of warm gutta percha were applied to the joints and squeezed crudely into shape with a wooden press.

This cable was not robust, to say the least. After only a few hours, it broke somewhere, or else rocks chafing at it wore through the gutta percha and allowed seawater to reach the copper wire inside.¹ Once that happened, any electrical current traveling down the wire would conduct away into the watery deep. Whether Brett’s first cross-channel cable ever worked at all is debatable. Charles Bright, in his 1898 history of submarine telegraphy, allowed that “some few, more or less incoherent, letters appeared here and there … but intelligible words were conspicuous by their absence.” Willoughby Smith, another telegraph engineer, suggested in his memoir that the letters allegedly received were no more than random firings of the equipment. According to him, the operators at Dover wondered at the time if their colleagues on the French side had overindulged in celebratory champagne. Still, Brett’s transient claim seemed momentous enough to the London Times, which remarked that “the jest or scheme of yesterday has become the fact of to-day,” while the Spectator presciently observed that in the future “a man in London might sign a

bill in Calcutta, transmit it for endorsement to St. Petersburg, and receive cash for it on authority in Cairo, in the space of an hour or so.”

Brett’s cable was not the first underwater telegraph, but it was the first of any length. In 1838 a Colonel Pasley had experimented at the Chatham docks in London with a wire wrapped in tarred rope. At the behest of the East India Company, Dr. William O’Shaughnessy trailed wires across the Hooghly River the following year. In the United States in 1842 Samuel Morse, whose 1837 electromagnetic telegraph and the code that he also devised became standards of the new technology, transmitted signals across New York Harbor. Charles Wheatstone, an English scientist who also made crucial contributions to telegraphy, signaled in 1844 from a boat in Swansea Bay, Wales, to a lighthouse on the shore. His cable had several copper strands twisted together, wrapped in hemp, and then soaked in boiled tar. The following year Ezra Cornell, founder of the university, laid a line 12 miles across the Hudson, from Fort Lee to New York City. His cable had two cotton-covered copper wires wrapped in rubber, further protected by a lead sheath. It worked for a few months, until a chunk of ice in the river severed it. Then gutta percha came on the scene, and in 1848 Werner Siemens ran a cable across the harbor at Kiel, in northern Germany. Siemens made the important invention of a press that molded warm gutta percha around a metal wire in a continuous run, producing seamless insulation.

In 1845, as news of these ventures and their mixed success was getting about, John Brett sent a telegram to Sir Robert Peel, the British prime minister, with a proposal both outlandish and grandiose. Fired by a vision of technical innovation allied to patriotism, he described a combination of “oceanic and subterranean inland electric telegraphs” by means of which “any communication may be instantly transmitted from London, or any other place, and delivered in a printed form, almost at the same instant of time, at the most distant parts of the United Kingdom or of the Colonies.” The advantages to a great and growing colonial power would be immense. The global might of the British Empire would surely come to depend on this technology and profit from it. Brett offered his technical abilities to his country, in return for financial support and some guarantees of exclusivity. For the sake of imperial might, the government must surely support his endeavors.

Her Majesty’s government did no such thing. The classically educated mandarins inhabiting Whitehall’s upper reaches were singularly uninterested in feats of untested technological novelty. As civil servants they were extremely adept, however, and repulsed Brett’s enquires by means of a practiced game of departmental handoff. Peel told Brett to try the Admiralty, which had authority over transoceanic communication. The Admiralty demurred on the grounds that they were not in a position to make business or financial arrangements; that was something the Treasury would have to deal with. Policy initiatives were not the Treasury’s bailiwick, however. Might this be a question for the Foreign Office to decide? But the FO’s remit was diplomacy and statesmanship, not technical questions of sending and receiving messages.

Rebuffed by one department after another, Brett made overtures to the French government with the more modest suggestion of a telegraphic link across the English Channel. The French showed a hint of interest, and Brett then returned to the Admiralty for permission to land a French-sponsored cable on British soil. The Admiralty said it had no particular objection, provided there was no expense to Her Majesty’s government and provided too that Brett would agree to cut the cable at once if their Lordships, for whatever reason might in the future occur to their wise heads, should so command. In a final stroke of bureaucratic genius, they advised Brett that if he wished to attach an electrical cable somewhere along the lovely southern coast of England, he would surely need to obtain permission from the Commissioners of Woods and Forests.

Brett’s correspondence with various offices of the British government appears in his book Brett’s Submarine Telegraph, which mainly purports to show how many important ideas were originally his and how unfairly history had already treated him by 1858, when he published his memoir in London. Nevertheless, reading the various irresistible explanations offered by civil servants and politicians of why they could not possibly take action on Brett’s proposal, one begins to wonder how the British Empire ever spread much beyond the Chatham docks.

In the end Brett gave up on London and made a deal with the French government. For his channel connection, let alone the global network he imagined, John Brett and his brother Jacob were woefully underprepared. Jacob had some technical experience, while John, a former antiques dealer,

supplied entrepreneurial talents. Their first contract, signed in 1847, lapsed after a year because they hadn’t done anything. They renewed in 1849 with the same stipulation that they must demonstrate the feasibility of their plan within a year. The 1850 cable barely beat the deadline.

With renewed financial backing, Brett laid a second cross-channel cable in September 1851. Where the first wire had been ridiculously flimsy, the second went to the opposite extreme. It consisted of four copper wires individually insulated with strips of gutta percha, applied cold (evidently they hadn’t heard of the Siemens machine for applying insulation). These conductors were then twisted together with strands of tarred Russian hemp, that assembly being wrapped and wound with tarred yarn, the whole thing then being wound about with 10 galvanized iron wires for strength and protection. The cable was almost two inches across and weighed a massive seven tons per mile. Laying the cable proved fairly easy, except that their boat drifted off course, so that Brett’s crew ran out of cable a mile from the French coast, off Cap Gris Nez. They improvised by filling in the gap with a length of the old wire but a month later managed to pick up the cable at the join, splice in an additional length of the new strengthened line, and complete the job.

Building on this success, the brothers Brett formed the European and American Telegraph Company and made a creditable attempt to corner the market on this new business. The Irish Sea at first proved too rough and deep for cabling, but they laid a 70-mile link from Dover to Ostend in 1853 and then began to attack the Mediterranean—an adventurous project, since no one knew how deep the water was in its middle sections.

Although the Bretts had remarkable entrepreneurial energy, they had inevitably to deal with the uncertainties and pure ignorance implicit in any new technology. John Brett, in his book, remarks a little testily that their endeavors were held back by his brother Jacob’s infatuation with a telegraphic letter-printing machine devised by Mr. Royal E. House of Vermont. That instrument, like the teletype machines of a few decades ago, printed messages on strips of paper in capital letters. Charles Wheatstone invented a similar device, similarly unwieldy. These machines, equipped with a rotating circular dial inscribed with the letters of the alphabet, had to receive a string of pulses down the telegraph wire in

order to know at which letter to stop and stamp out a mark. They were both slow and unreliable.

Samuel Morse’s famous code stands as an innovation of middling genius. He saw how to get two kinds of intelligible signal—dots and dashes—down a telegraph, and he devised a system for turning bursts of dots and dashes into the letters of the alphabet in an economical way. We take this for granted nowadays, it seems so elementary, but at the time it arrived like a godsend. As Werner Siemens put it: “The simplicity of Morse’s apparatus, the relative facility of acquiring the alphabet, and the pride which fills everyone who has learned to use it, and which causes him to become an apostle of the system, have in a short time ousted all dial and older letter-printing apparatus.” Jacob Brett’s devotion to the letter-printing device of Mr. House represented years of wasted time.

More mundanely, John Brett displayed a habit of packing not quite enough cable on his early expeditions. That was not such a silly mistake as it might seem. Keeping a vessel on course while it was dropping cable off the stern was not easy, as Brett had found on the 1852 cross-channel project. A more serious difficulty showed up four years later when he tried to lay a connection from Sardinia to the north coast of Africa. This was a distance of some 150 miles, across water up to 1,600 fathoms deep. In August 1856 Brett and his crew loaded up with cable and sailed south in perfect weather, with clear sky, little wind, and a calm sea. But as they moved into waters deeper than anything they had experienced thus far, their cable unreeled over the stern with alarming and increasing speed. The explanation is simple. The deeper the water, the greater the length of unsupported cable that dangles from the ship; this greater hanging weight pulls the cable from the ship uncontrollably fast. In earlier and easier Mediterranean expeditions, Brett had added a brake to the drum that paid out the cable, for precisely this reason. But in these deep waters they could barely restrain the cable.

Sailing to their utmost, they found themselves 13 miles from the African shore with 12 miles of cable on board. Desperately, they lashed and buoyed the cable to keep the remainder from spilling into the sea and sent a request for additional cable back along the cable they had already laid. Then the weather turned bad. Squalls blew up and the ship, pitching and rolling, hung on desperately to the heavy cable end. After

five days their ordeal came to an abrupt end. Chafing against the stern of the ship, the cable finally broke on August 19, “not ten minutes after receiving a telegraphic reply through it from London, to inform us that the extra cable was in progress, and would speedily be forwarded to us,” as Brett ruefully recorded.

Despite such setbacks, John Brett established himself for a time as the leading figure in submarine cabling. When Frederick Gisborne, a globe-trotting Englishman then resident in Canada, began to think seriously of an underwater telegraph across the Atlantic Ocean, connecting the New World to the Old, it was Brett whom he first contacted. Gisborne was struggling to overcome enormous difficulties of geography and climate in order to lay a mix of overland and underwater cables connecting the east coast of the United States to the tip of Newfoundland. From there it was less than 2,000 miles to the west coast of Ireland. The idea of a transatlantic cable was not unique to Gisborne. Morse had written in August 1843 to the secretary of the U.S. Treasury making just that proposal, with casual and quite unfounded confidence that the project would present no new difficulties beyond the obvious logistical ones.

But Morse simply made a suggestion. Gisborne spent years hacking through the wilderness of Newfoundland in preparation for a practical attempt. He first proposed a route that included a way station in Iceland, but his Canadian ventures proved far more costly than he had imagined, and by the mid-1850s he was on the verge of bankruptcy. His savior was not Brett but a newcomer to the cabling business, a New York entrepreneur and financier by the name of Cyrus West Field. In the end both Gisborne and Brett faded from their pioneering roles, and it was Field’s stamina, imagination, and financial resources that saw the Atlantic telegraph project through to a successful conclusion. But money was not the only necessity. Scientific problems also stood in the way, and to resolve those Field needed the best scientific advice he could find.

***

Though William Thomson was never as keen a student of current affairs as his father had been, he surely knew of the blossoming of telegraphy, both overland and undersea, into a new industry that rapidly altered

the pace of ordinary life. It was, moreover, the first commercial technology that depended on electricity, one of the many subjects in which Thomson held acknowledged expertise. Still, it was some time before he first began to think critically about telegraphy as an exercise in the theory and application of electricity. Overland telegraphy would not have fascinated him. A battery applied at one end of a wire produced a detectable signal (instantaneously, it seemed) at the other. The fundamental nature of that signal, how it moved, why it would pass through copper or iron but not through tar or cotton or gutta percha—these scientific arcana mattered not in the least to inventors such as Morse, still less to the money men Brett and Field. Telegraphy was a simple means of communication making use of an utterly mysterious physical phenomenon.

That was the case, at least, until the advent of underwater cables. Signals transmitted through the 1851 Dover-Calais cable, and more obviously in the 1853 Dover-Ostend and later Irish cables, suffered from a troubling degree of fuzziness. What should have been clear and unambiguous blips came through distorted and blurred, sometimes to the point that operators couldn’t be sure whether they had registered a real signal or not. These difficulties alarmed George Airy, the astronomer royal, who had conceived a plan to link the London and Paris observatories by telegraph so as to allow simultaneous observations from both places. By this time there were enough telegraph lines around Britain and the continent that it was possible to set up test circuits in which signals traveled along hundreds or even thousands of miles of wire in the air, underground, and underwater. Experiments showed that underwater cables, and to a lesser extent underground ones, suffered a small but detectable delay in transmission. Instead of an instantaneous sharp pulse, operators would see a signal both delayed and smeared out.

Airy asked a young telegraph engineer, Josiah Latimer Clark, to look into the problem. One day in early 1854 Clark invited the renowned Michael Faraday to visit his cable works and observe some experiments. He had coiled 100 miles of cable in a tank full of water and demonstrated to Faraday that it transmitted signals more slowly and less clearly than a 1,500-mile circuit of overland cable looping around the country. Faraday immediately supplied a qualitative explanation. Any signal passing down a wire creates an electrical disturbance in its vicinity. Water, unlike dry

air, has significant electrical conductivity, and an electrical disturbance passing through it creates local electric currents that act as a kind of inertia or brake on the primary signal. In essence, Faraday told Clark, a signal passing through a submerged wire has to work harder to get from one place to another—hence the delay and degradation in the signal.

Faraday published his analysis of the problem in the Philosophical Magazine, where he also compared a long insulated conductor, immersed in water, to the familiar laboratory device known as a Leyden jar. A Leyden jar (named after the Dutch city where it was invented) was a glass vessel lined inside and out with separate layers of metal foil. With the external layer grounded, the inner layer could be charged with static electricity, which the jar would then retain. The two metal layers, separated by glass insulation, acted as a storage device for electric charge—in modern parlance, a capacitor.

An underwater cable, Faraday observed, had a conducting core surrounded by a layer of insulation, which was surrounded in turn by an earthed conducting body, the ocean. Such a cable did not simply conduct electricity but stored it too. Its characteristics were therefore quite different from those of a plain wire, but Faraday, in his usual way, perceived the essential physics of the matter without being able to calculate anything. Nevertheless, if poorly understood electrical phenomena were already causing trouble on the 70-mile cable from England to Holland, the prospects for a link of 2,000 miles or more across the Atlantic Ocean must be questionable.

The problem finally came to Thomson’s attention in a roundabout way. At the close of the 1854 British Association meeting in Liverpool, a young man had introduced himself to Thomson as the son of the Dublin mathematician William Rowan Hamilton. He wanted to ask an electrical question. Thomson had to rush away to catch a steamer to Glasgow and handed the young man off to his friend George Stokes. The question concerned Faraday’s analysis of undersea cables. Stokes, no electrical expert, couldn’t help and so passed the problem back to Thomson in a letter dated October 16, 1854. Thomson was by then at Largs, on the Ayrshire coast. He had a couple of weeks remaining before the Glasgow session began and spent the time catching up with correspondence but also, as he told Stokes, “devoting myself as much as possible to the open

air & the sea.” He did not have access to the Philosophical Magazine, so could only infer Faraday’s arguments from Stokes’s brief account of them. But that was all he needed. “In taking up your letter this morning to answer it,” he wrote, “I find that the whole may be worked out definitely as follows.” In several pages of calculations Thomson worked out, as no one had done before, the theory of the transmission of a pulse of electricity down an insulated underwater cable. A second letter, two days later, added further details, notably some calculations of the feasibility of a telegraphic connection to America. This was an exercise in applied science, carried out by Thomson with his customary speed and brilliance, and done simply to satisfy his curiosity about a physical phenomenon that was new to him. He did not immediately feel any great urge to polish his analysis into a scientific paper, nor did it occur to him that his findings might have practical not to say commercial importance. Through November he exchanged further letters with Stokes, working out some additional wrinkles. Stokes helped by coming up with a simpler way to obtain solutions to the fundamental equation of telegraphy that Thomson had worked out.

Thomson’s innocence ended abruptly. On December 1, 1854, he wrote asking Stokes to keep quiet about the contents of his previous letters because he had applied for a patent on “the remedy for the anticipated difficulty in telegraphic communication to America.” Joining in this application were William Rankine (whom Thomson knew from his work in thermodynamics) and John Thomson (not William’s deceased brother John, obviously, but a son of the other William Thomson, the medical professor). Writing to his brother James the following January, Thomson explained that it was Rankine, the experienced professional engineer, who had “suggested the plan of taking a patent, w^h I had no idea of at first. In a few days I expect it will be secured to us: in the meantime don’t say even as much as I have said to you, on the subject. I am not very hopeful of making anything of it, but it is possible it may be profitable.”

Before Thomson’s theoretical analysis, no one had designed an underwater cable except in a crude way. There had to be a copper conductor down the middle, surrounded with gutta percha for insulation, made watertight with tar and pitch and hemp and rope or whatever else came

to hand, and finished off with some sort of iron binding for strength and protection. Thomson modeled such a cable as a combination of resistance and capacitance, with the magnitude of these factors depending on the construction of the cable. The thicker the wire, the less the resistance, but the thicker the insulation, the greater the cable’s capacitance. In effect, an electrical pulse traveling down an insulated underwater wire had to charge up the cable as it went. The consequence, Thomson showed, was that a sharp pulse applied at one end spread out, as it moved along, into a rolling wave of increasing length.

Thomson obtained the curious result that the arrival time of this changing signal, if measured by the moment the crest of the wave reached the far end, increased with the square of the distance traveled. In other words, the signal had no fixed speed. Although the front of the pulse moved at a constant rate, the crest of the following wave lagged farther behind, the farther it went. Alternatively if the diameter of both the conductor and the insulation of a cable were increased in proportion to its total length, then the signal delay and what Thomson, groping for technical language to describe the clarity of the signal, quaintly called the “distinctness of the utterance,” would remain the same. Collectively, these assertions became known as the law of squares in telegraph theory.

This seemed at first a discouraging discovery. If a cable 100 miles long was an inch or two in diameter and weighed a ton or two per mile, one could hardly countenance 2,000 miles of cable measuring a foot and a half across. Thomson argued, though, that with a strong enough signal and sufficient patience and understanding on the part of the operators, signals could be sent and received across the Atlantic, though at a limited rate compared to what had been achieved over the modest subocean distances traversed thus far.

Thomson published his paper “On the Theory of the Electric Telegraph” in the Proceedings of the Royal Society for May 1855. He reproduced with little modification the reasoning he had worked out within a few hours of reading the letter from Stokes. His solution once again owed a good deal to his youthful reading of Fourier. An electric pulse moving down a wire against both resistance and capacitance, he argued, was directly analogous to heat migrating along a metal bar. In later papers he found an alternative analogy: He likened the pulse to a surge of water

passing down a rubbery pipe that expanded in response to increased pressure. This he called his “peristaltic” model of signal transmission. Thomson was never happier than when he found analogies between one problem and another. It indicated the universality of his reasoning. It maintained his strategy of modeling phenomena from empirical and observational laws, rather than striving for some fundamental a priori theory that would yield results as mathematical theorems. What electricity was, in some essential way that would satisfy continental adherents of la physique or devotees of German Naturphilosophie, was of no consequence. What mattered, in Thomson’s view, was to find a solution to the problem at hand, not to worry about questions of “metaphysics.”

***

Even in the middle of the 19th century, the application of science to technology had barely begun. Thomson, with others, had worked out the fundamentals of thermodynamics, but the builders of steam engines mostly worried about cracked cylinders and poor insulation. The pioneers of telegraphy were less scientifically aware still and even those who pretended to a little knowledge of electricity found Thomson’s broad-ranging science and powerful mathematics beyond them. One who failed to understand his reasoning but disputed his findings anyway was the splendidly named Edward Orange Wildman Whitehouse, a successful physician in Brighton who had caught the telegraphy bug and begun experimenting with cables and electricity not long before Thomson came across the subject. Attending the British Association meeting in 1855, in Glasgow, Whitehouse heard Thomson announce the law of squares. At the BA the following year he recounted his own tests of signal transmission through cables of various lengths, which he claimed contradicted this supposed law.

Thomson, in Germany with his invalid wife, did not hear this rebuttal but read about it soon after in the Athenaeum, a London magazine, which reported that Whitehouse “has been able to show most convincingly that the law of the squares is not the law which governs the transmission of signals in submarine circuits.” Whitehouse’s account from the BA meeting itself was so confused, both as to what he did and whether he understood what he was doing, that Thomson had difficulty responding.

Whitehouse had tested three cables, each 83 miles long, “coiled in a large tank in full contact with moist earth, but not submerged,” which he could join to make a cable of 166 or 249 miles in total length. He also had access to a longer cable, presumably an underground one, that gave him a total of 1,020 miles. Whitehouse may or may not have understood that an underground cable, surrounded by damp earth, represented an intermediate case between a cable in dry air and one immersed in water. Later he remarked without explanation that he thought a cable wrapped in iron could be regarded as identical to one underwater. Without describing in any detail what exactly he measured, he claimed the transmission time was proportional to the length of the cables he tested, not the square of the length. This boded well for the Atlantic project, he said, and he concluded with an airy dismissal of Thomson’s so-called theory of the telegraph, implying that ivory-tower academics shouldn’t meddle in the affairs of practical men: “And what, I may be asked, is the general conclusion to be drawn as the result of this investigation of the law of squares applied to submarine circuits? In all honesty, I am bound to answer, that I believe nature knows no such application of that law; and I can only regard it as a fiction of the schools, a forced and violent adaptation of a principle in Physics, good and true under other circumstances, but misapplied here.”

Thomson replied briefly at first, saying without elaboration that he thought Whitehouse’s results were consistent with the law of squares, despite any appearance to the contrary. Whitehouse then sent Thomson a more detailed account of his tests, to which Thomson wrote a thorough rebuttal. He explained that the law of squares applied to uniform tests, wherein precisely the same signal was applied to a cable, and the time of maximum response at the other end was recorded. Whitehouse had not arranged for a constant input and timed his detection at the other end as soon as he saw something. Responding again in the Athenaeum, Whitehouse seized on Thomson’s admission that the applicability of the law of squares “depends on the nature of the electric operation performed at one end of the wire, and on the nature of the test applied at the other extremity” and argued that the practical issue was to get a useful signal down the wire, not to operate according to some theoretical ideal.

This was a fair point. Although Whitehouse clearly didn’t under-

stand Thomson’s theorizing, it was also true that Thomson had not fully thought through the implications of his theory for practical telegraphy. His analysis of the telegraph illuminated both the strengths and the weaknesses of Thomson’s intellectual style. He began with a handful of basic empirical propositions about electricity, used them to formulate a simple model of the properties of an insulated submarine cable, and proceeded to write down a differential equation that captured the desired solution. In his first reply to Whitehouse he had expressed his confidence in this approach by saying that his theory, “like every theory, is merely a combination of established truths.” One does not have to be a deep philosopher to perceive the narrowness of this view. There must be more to theorizing than simply combining old knowledge in new ways, else where would new ideas come from?

There was also the problem that the “established truths” of electricity known to science at that time were far from complete. Thomson’s telegraph theory, as it turned out, had serious flaws. It was not for another decade that a full theory of electricity and magnetism came into being, which would eventually allow a comprehensive treatment of signal transmission. Thomson’s blithe certainty in his analysis seems at best like overconfidence, at worst an indication of a blindness to or incuriosity about the evolving nature of scientific understanding.

On the other hand, Thomson’s venture into telegraphy gave at least a preliminary explanation for the unexpected behavior of submarine cables and showed that engineers would ignore the arcane lessons of natural philosophy at their peril. For the time being, the exchange between Thomson and Whitehouse concluded with protestations of good will on both sides and acknowledgment by both that anyone proposing to build an Atlantic cable would be wise to test and investigate thoroughly before proceeding with so ambitious and expensive a project.

Cyrus Field was just the man not to do this. That same year, 1856, he came to England on one of what would eventually total 56 transatlantic voyages, each costing almost two weeks of his life. Born in Stockbridge, Massachusetts, in 1819, Field had worked his way up from junior clerk in a New York dry goods store to become the preeminent paper merchant in the city before he was 30 years old. He had that power of spontaneous adaptability essential to business success. Anticipating the modern cliché,

he saw opportunity in every problem. He specialized in high-quality papers for an upmarket clientele, avoiding the low-margin trade in newsprint. He saw an interest in colored paper and urged his suppliers to see what they could come up with. Dyeing was an uncertain process and batches came out in unpredictable hues. Field rose to the challenge. When he took delivery of a parcel of red paper that was a little paler than it should have been, he called it “salmon” and marketed it at a premium. When the blue came out a little darker than usual, he wrote to his privileged customers to tell them of their unexpected opportunity to obtain a quantity of “extra blue” paper that had come his way.

By the late 1840s Field was selling up to $500,000 worth of paper a year, but he began to tire of business and took off with his wife on a tour of Europe. There, especially in London, he encountered a level of industrialization and technological development he hadn’t seen before and saw the energy and affluence that both produced it and derived from it. By 1852 he was one of the 30 richest men in New York, worth more than $250,000. Quixotically he then left his paper business in the hands of colleagues, set off on an unhappy expedition to South America with the painter Frederic Church, and returned to New York in 1854 with enormous wealth and ambition but no settled purpose.

Meanwhile, his brother Matthew had teamed up a couple of years earlier with Frederick Gisborne, the Newfoundland telegraph engineer. So far they had spent huge amounts of money tackling the intractable and dangerous Canadian wilderness, had failed to complete their planned telegraph line from New York City to St. John’s (a distance of more than 1,000 miles), and were piling up debt. Now here was a project momentous enough for Cyrus Field. Field contacted Morse, who assured him blithely that no serious technical problems stood in the way of an Atlantic cable. While Matthew Field and Gisborne toiled away in the distant wastes of eastern Canada, Cyrus Field took over the project, formed a consortium, raised money, and in 1855 sailed for England to meet John Brett, who at that time could claim the greatest success and expertise in the laying of submarine cables.

The only commercial manufacturers of undersea cable were in Britain. Field, with Brett’s assistance, ordered a quantity of cable for the marine segments of the Newfoundland cable (across the St. Lawrence and

from Cape Breton to Newfoundland itself). By the following summer the American end of the Atlantic cable project was close to completion, at a cost exceeding $1 million. The transatlantic link itself would cost considerably more than that. Field tried but largely failed to raise money in New York and in 1856 sailed for England again. In a hectic trip lasting several months, he consulted Brett and his assistant Charles Bright, who at only 23 had already overseen the laying of a cable from England to Ireland. Field ordered 2,500 miles of insulated copper wire from the London Gutta-Percha Company, with spiral-wound iron sheathing to be supplied by two other companies, R. S. Newall and Glass, Elliott. He obtained conflicting advice from Whitehouse, Thomson, and Faraday about the delay and distortion inherent in undersea transmission. In October he formed the Atlantic Telegraph Company, with Brett as president, himself as vice-president, Bright as chief engineer, and Whitehouse (who now gave up his Brighton medical practice altogether) as chief electrician.

The appointment of Whitehouse was fateful but by no means foolish. Thomson had only just begun his foray into applied science, and though he had made the general point the cable design ought to be guided by scientific principles, it was by no means clear that electrical science was thus far well enough advanced to be useful. Samuel Morse, moreover, had visited in England in 1856, where he tested long cables in collaboration with Whitehouse and pronounced both the man and the results satisfactory. Thomson was 32, five years younger than Field; Whitehouse was 40, had practical experience in cabling and electrical testing, and in his career as a physician had acquired business sense.

The Atlantic Telegraph Company issued 350 shares at £1,000 each, which Field, racing around the country giving inspirational speeches in all the big industrial cities, sold in less than two weeks. This represented $1.75 million in capitalization. Among the subscribers was William Thackeray, who had met William Thomson and his “nice wife” some years earlier. With the selling of the shares Field also established an unpaid board of directors, which included Thomson.

If Whitehouse and Thomson agreed on one thing, it was that cable design ought to be thoroughly tested before the great adventure began. But with Field in charge, there was no time. He wanted to order cable

now, for a voyage the following summer. Thomson didn’t like the design adopted (he thought the copper core too thin), but Whitehouse, with his more optimistic view of signal transmission, saw no problem. On his own initiative, Thomson embarked on a study of the quality of copper supplied by several British foundries and to his alarm found that the electrical resistance of copper wire of the same alleged gauge and purity varied in some cases by more than a factor of two. But it was the middle of 1857 when he discovered this. Cable for the first attempt had already been made, and Field had persuaded the U.S. and British governments to lend him two large ships, the U.S.S. Niagara and H.M.S. Agamemnon. With armaments removed, interior structures torn out to create vast holding tanks, and with systems of drums and brakes and pulleys mounted on the stern, the two vessels became the world’s first ocean-going cabling ships. Field needed both, because no single ship was large enough to carry 2,500 miles of cable.

Early in August 1857, Niagara and Agamemnon lay at anchor a mile or two out from Valentia Bay in the southwest corner of Ireland. Bright had argued that the ships should meet in mid-Atlantic, splice their cable ends together, then sail for their respective home shores. The cable might then be laid in only a week, if all went well. But others, notably Whitehouse, insisted on starting from Ireland, so that progress reports could travel down the cable as it was laid. The departure of the ships was a gala occasion, with speeches and toasts and festivities. Field delivered a message from President Buchanan, inviting Queen Victoria to send the cable’s first message to him. On August 5 a small ship brought one cable end ashore, where it was hooked up to the telegrapher’s office. Whitehouse had planned to sail on the Niagara to oversee communications to shore, but he either fell ill or suffered an attack of the nerves, and Thomson went in his place.

It was a brief trip. The Niagara steamed about four miles out, when the cable got tangled in the paying-out machinery and broke. The ship returned and tried again. By noon on Sunday, August 9, signals were coming to shore from almost 100 miles away. The crew struggled constantly with the clumsy system for letting the cable go from the stern of the ship. The crude device for maintaining even tension proved hopelessly inadequate, and as the Niagara rose and fell the threat of losing the

wire was ever present. As the ship sailed into deeper water, the weight of cable hanging from the stern became increasingly unmanageable, and the crew had endless difficulty braking the drum enough to stop the cable from reeling out but not so much as to snap it. On Tuesday the signal through the cable ceased. Later in the day (at a time, Bright helpfully noted in his memoir, when he was away from the machinery), an ill-timed application of the brake as the ship rose on a swell put the strain on the cable past breaking point—and break it did. About 300 miles of cable dropped uselessly to the seafloor.

Back at Valentia the engineers tallied the remaining length of cable. Just over 1,800 miles—about 10 percent more than the distance from Ireland to Newfoundland, they reckoned, but that was not a sufficient margin of error. With the enthralled crowds of a few days earlier now vanished, the directors quickly decided to abandon the attempt but not before agreeing to try again next year. Niagara and Agamemnon sailed back to Plymouth, where the cable was off-loaded into covered tanks of water for storage through the winter. (Gutta percha dried out and became brittle under prolonged exposure to light.) Another 600 miles of cable was ordered. This first attempt at the great project, Field was quick to assert, had been far from ignominious. They needed better paying-out machinery. The cable itself proved adequate. Next year would be different.

***

Field, concurring with Bright and the other engineers, believed that improvements in the paying-out system would solve all their problems. Thomson contributed some thoughts to the design of tensioning and braking equipment, but Field put such matters in the hands of William Everett, chief engineer of the Niagara, who adapted existing ideas and designs to the task of cabling. In any case Thomson’s interest lay mainly in electrical questions, in which he did not share at all Whitehouse’s complacency. In his paper on the quality of commercial copper, he said he “was surprised to find differences between different specimens so great as most materially to affect their value in the electrical operations for which they are designed” and argued “how important it is to shareholders in submarine telegraph companies that only the best copper wire should be

admitted for their use.” He had evidently grasped by this time that the way to convince businessmen of the gravity of a scientific problem was to show that it would cost money if not solved. Still, at least in Thomson’s own account, it took much stubbornness and persistence on his part to bring the directors around to his point of view.

At Thomson’s insistence, the board added a clause to its contract with the Gutta-Percha Company demanding an insulated wire of verified high conductivity. No can do, was the first response. The board then asked what price the company would charge to conform to the new terms: £42 per mile instead of £40, came the answer, which the board agreed to. Thomson then helped set up a testing station at the factory so that the quality of the wire could be constantly monitored. Thomson’s determination on this point thus led to the first scientifically informed quality control system for the manufacture of a commercial product. As he later commented, “It was not until practical testing to secure high conductivity had been commenced in the factory, that practical men came thoroughly to believe in the reality of the differences of conductivity in the different specimens of copper wire, all supposed good and supplied for use in submarine cables.”

A second matter on which Whitehouse was complacent and Thomson nervous was that signaling across the Atlantic placed new demands on the sensitivity of the receiver. In standard telegraphy equipment, from the letter-printing machines of Wheatstone and House to the superior Morse receiver, a current ran through a coil, creating a magnetic field, which attracted or repelled an adjacent permanent magnet. The energy to move the magnet ultimately came from the current—a point that derived ultimately from Joule’s experiments on the energy carried by electricity, although such thinking was not yet familiar to practical engineers. Thomson began to think of detecting the signal with a galvanometer, a laboratory instrument for detecting small currents. At the end of 1856 he wrote to Helmholtz asking for details of an instrument he had designed. The principle of a galvanometer was the same—a coil produced a force on a magnet attached to a pointer—but a good one was carefully made and well balanced, with lightweight components, and was far more sensitive than the heavy devices found in telegraphy offices.

Thomson at first imagined he would simply take apart one of

Helmholtz’s galvanometers and see what he could do to reduce the mass of the moving parts. But in a stroke of inventive brilliance he saw how he could reduce the mass of one moving part to nothing at all. Inspired, so he liked to claim, by light reflecting off a monocle dangling around his neck, he substituted for the moving magnet-and-pointer arrangement a tiny piece of magnetized steel that he glued to the back of a piece of mirrored glass and suspended by a short fiber. (In the first attempt he used a hair plucked from his dog; later he substituted a silk thread from one of his niece Agnes’s dresses.) A current passing through the nearby coil created a field that twisted the magnet one way or another, and by directing a light beam onto the mirror in such a way that the reflected spot swung back and forth across a graduated scale, he created a weightless pointer for his galvanometer.

The mirror galvanometer, as he dubbed it, was the subject of Thomson’s second patent, taken out in 1858. Having made a prototype, he requested the substantial sum of £2,000 from the Atlantic Telegraph Company to build a number of instruments for use with the cable to be laid later that year. The directors, yielding to Whitehouse’s opinion, turned him down, but later he managed to get £500, along with permission to test the mirror galvanometer during the voyage. (His professorial salary was not much more than £200 per year.) In April he went to Plymouth to test the cable stored there and got three letters per second through the entire length—some 2,700 miles. At the end of May the Agamemnon set course for the Bay of Biscay to conduct deep-water tests of the new paying-out machinery. Whitehouse was supposed to go along to oversee electrical tests, but again he backed out at the last minute, leaving the field to Thomson and his new galvanometer. All went well, both mechanically and electrically, but by the time the Agamemnon and Niagara returned to Plymouth to prepare for the transatlantic voyage, Whitehouse was firmly ensconced in the electrician’s office and doing his utmost to resist Thomson’s appeals for better equipment and more testing.

Dissension simmered among the officers and directors of the Atlantic Telegraph Company. Thomson’s initiative, inventiveness, and obvious enthusiasm for the project contrasted with the increasing recalcitrance of Whitehouse, who complained openly about “the frantic fooleries of the

Americans in the person of Mr. Cyrus Field.” Morse, who had also clashed with Field over technical choices, dropped out of active participation. But Whitehouse was still chief electrician and Thomson an unpaid adviser. Both appeared eager to travel with the 1858 cabling voyage, Thomson because he wanted to demonstrate the virtues of his mirror galvanometer, Whitehouse to prove he was in charge. Field tried delicately to make sure they went on different ships. But at the last minute, as he had done previously, Whitehouse announced he couldn’t or wouldn’t go. Thomson boarded the Agamemnon while Whitehouse arranged to go to Ireland to await signals coming down the wire.

Also working to Thomson’s advantage was the fact that the directors had now agreed to Bright’s preference of having the ships meet in midocean and lay the cable from there out to both shores simultaneously. Whitehouse would have nothing to do unless or until a cable end reached Valentia, while Thomson, though still acting in what was formally described as an advisory role under engineer C. W. de Sauty, became the de facto electrical authority on the Agamemnon. On June 10, 1858, the two ships, so weighed down with cable that “experienced mariners gazed in apprehension at their depth in water as they left the shore” departed for the mid-Atlantic rendezvous, accompanied by a fleet of smaller vessels. The project almost ended in catastrophe before it began. Ten days out a monstrous storm blew up. The Niagara, the larger and stouter ship, steered clear of the worst. The Agamemnon came close to sinking. There was not enough room below deck for all the cable she carried, and some 250 tons was lashed on the upper deck, making the ship dangerously top heavy. She became unsteerable and sat helplessly in seas that heaved over the decks, rolling her over at 45 degrees to one side then as far to the other. Deck planks, already strained by the weight of cargo, separated and let water flood below. The electrical cabin, with Thomson striving to save his equipment, was washed out. Coils of cable broke loose and flailed about; below, coal burst out of the holds and crashed back and forth as the ship lurched from side to side.

After a perilous night, the storm began to abate. Ten sailors had been injured, but the ship remained seaworthy and no cable had been lost. The Agamemnon steamed on to the rendezvous, joining the Niagara on June 25. The next day the crews attempted to splice together the cable ends from the two ships but encountered an absurd difficulty. Half of the

cable sheathing had been made by R. S. Newall, the rest by Glass, Elliott. Because of the haste of manufacture and lack of planning, it turned out that one company had wound the protective iron sheathing clockwise, while the other had done the opposite. Had the two ends been spliced directly together, tension on the cable would have caused both windings to unravel. The engineers had to improvise an ungainly wooden bracket through which the cable ends were wound and secured, allowing them to be joined.

Finally, on June 26, the ships began to sail apart, connected by a cable through which they maintained electrical contact. After only a few miles, the cable snagged in the Niagara’s paying-out machinery and broke. By prior agreement, if contact was lost, both ships were to return to the rendezvous and try again. On the second attempt they managed about 40 miles before the cable broke again. A third time they tried. The Niagara had sailed a little over 100 miles, the Agamemnon almost 150, when the cable parted as it was disappearing over the latter’s stern. Now fog had descended, and the ships failed to find each other. Both returned to Ireland.

In two voyages Field and his colleagues had succeeded only in scattering several hundred miles of costly cable at various places on the floor of the Atlantic. Field, along with most of the engineers and electricians, wanted to try again. They still had plenty of cable and plenty of time before winter weather would begin to threaten. But many of the financiers, who had by now seen hundred of thousands of dollars slip to the bottom of the sea, were ready to wrap up the Atlantic Telegraph Company and label the entire enterprise a noble failure. Field, the consummate salesman, prevailed again, and by the end of July the fleet, recoaled and reprovisioned, was back in the middle of the Atlantic.

Despite the catalog of mishaps and errors thus far, the third attempt was a charm. Around midnight on July 28 the splice was made. The Niagara sailed west and arrived on August 5 in Trinity Bay, near the optimistically named hamlet of Heart’s Content, Newfoundland, trailing behind it a cable that was still receiving signals from the other ship. The Agamemnon had a slightly harder journey, against difficult weather. On the first day Thomson and his colleagues suffered through an hour and a half of anxiety, after the mirror galvanometer abruptly ceased to register the periodic signal sent from the other ship. Thomson emerged from the

electrical cabin “in a fearful state of excitement. The very thought of disaster seemed to overpower him. His hand shook so much that he could scarcely adjust his eyeglass. The veins on his forehead were swollen. His face was deadly pale,” wrote the London Times reporter sailing with the expedition. Thomson told Bright he thought the conductor somewhere in the cable was broken but that the insulation was intact. He waited anxiously “in a perfect fever of nervous excitement, shaking like an aspen leaf, yet in mind clear and collected, testing and waiting, with a half-despairing look for the result.” So he and Bright and the rest waited, in dread of another failure. At one point someone saw the light spot from the mirror galvanometer twitch through an unmistakable 40 degrees, but Thomson, dashing into the operations room, saw nothing. Then just a few minutes later signals from the Niagara began to come through again. The engineers convinced themselves that the cable had suffered a minor fault as it was sinking to the seabed but that once laying there securely, in frigid temperatures and under enormous pressure, the gutta percha had healed and all was well again. It did not pay to think too much about what might have gone wrong.

By August 5 the Agamemnon had reached Valentia, where Thomson was obliged to hand over the cable to Whitehouse’s care. Field, in Newfoundland, telegraphed an announcement of the success to New York. “The electrical signals sent and received through the whole are perfect,” he declared. “By the blessing of Divine Providence it has succeeded.” The unexpected news, after such lamentable beginnings, set off hysteria in the press and in the streets. From Bangor, Maine, to Washington, D.C., and inland to Cincinnati and Chicago, church bells pealed out, bonfires blazed, cannons roared. Mayors pontificated, ministers offered up grateful sermons. “The Great Event of the Age … Triumph of Science … London within a Flash of New York … This news will send an electric thrill throughout the world” blared the New York Herald on the morning of August 6.² In succeeding days newspapers carried more tidbits of news,

delivered in triumphal style. But the tone of the reports gradually changed. Messages from Newfoundland said that all was well, that adjustments were in hand, that signals were coming through. But where, the press began to ask, was the inaugural message from Queen Victoria to President Buchanan?

On August 7 the New York Post felt obliged to assure its readers that “the rumors of deception and trickery, &c., &c., have not the least foundation, so far as we know or believe,” but just a week later the paper published a letter from a knowledgeable correspondent saying that the emanations from Whitehouse and his aides to the effect that they needed another five or six weeks were “enough to awaken in the sanguine unpleasant apprehensions, and to strengthen the doubters of the enterprise. The question is continually asked, Why should six weeks, or even one week, or even one day, be required for making the ‘experiments’, when everybody knows, who knows a little of practical telegraphy, that if the connection is good, one hour is sufficient for putting up the batteries and adjustment?”

In London the board of the Atlantic Telegraph Company was growing similarly restless. Thomson had left Ireland a few days after landing, and Whitehouse, still insisting on the need for unspecified adjustments, refused to say what he was doing in the telegrapher’s hut at Valentia. The New York newspapers reprinted confused comments from the London Times and added their own scraps of intelligence from Newfoundland, such as this item of noninformation issued on August 13. In response to numerous inquiries, said the telegraph operators, “we are unable to return any other answer than that the cable remains all right—the electrical signals passing through its whole length satisfactorily—but that the electricians have not yet concluded their arrangements for putting their recording instruments into operation.”

“Where’s the Queen’s message? Is the insulation perfect? Will the Atlantic telegraph work? Why don’t they give us the information?” inquired the exasperated editors of the Herald on August 16, who complained further about the secrecy surrounding Whitehouse’s “experiments.”

Just as skepticism erupted openly, however, jubilation squelched it. The following morning the Herald was back with stacked triumphal head-

lines: “The Queen’s Message to the President of the United States … The President’s Reply … Another Great Problem Solved … Tremendous Sensation Throughout the City … Everybody Crazy With Joy … Now’s the Time for a Universal Jubilee … &c., &c., &c.” The Post remained more skeptical, editorializing thus: “True, the Queen’s message bears no date, neither do we have any intimation of the time it has taken to transmit it—whether an hour, day, or week—nevertheless, we are assured, upon the faith of the Atlantic Telegraph Company, that it was actually transmitted from Ireland to Newfoundland by a submarine electric telegraph.”

Then in succeeding days came actual news. England and France had concluded a treaty with China, ending hostilities there. The Indian Mutiny was coming under the control of imperial forces, and the British government sent an order through the telegraph countermanding the dispatch of a regiment of troops from Canada to India. This action alone, boosters of the cable were fond of pointing out, saved the government £50,000. For a couple of weeks, hundreds of messages went back and forth: news, political communications, commercial transactions. New York City threw an enormous gala for its heroic son, Cyrus Field, on September 1, with half a million people thronging the streets, a parade that took hours to pass down Broadway, and a great banquet that went on past midnight. “Glorious Recognition of the Most Glorious Work of the Age … Reunion of all the Nationalities … Art, Science, Commerce, Agriculture, Literature and the Mechanic Forces Joined Hand in Hand,” trumpeted the Herald.

Among its many virtues, the cable would bring peace to the world, or so said the Post the following morning: “It is the harbinger of an age when international difficulties will not have time to ripen into bloody results, and when, in spite of the fatuity and perverseness of rulers, war will be impossible.” But just four days later there was a sharp change of tone: “It is rather unfortunate that, during the whole week that was spent by our City Fathers in celebrating the electrical union of the Old World with the New, we have not been favored with a single evidence of its usefulness. Not a single public despatch has traversed the wire for some ten days or more.” As September wore on there were only enigmatic reports of further difficulties and reluctant admissions by the Atlantic

Telegraph Company that no signals were at present being received, though experiments and tests continued. It seemed there was a difficulty at the Irish end, “near the shore, and remediable.” Shares of the company, sold at £1,000 apiece, were down to £500 or less. By the end of the month the hard news could no longer be concealed: The cable had fallen silent.

The exact cause of death could never be established. The cable had worked, but it had never worked well. Signals, often fragmentary or unreadable, often had to be repeated over and over until a message successfully got through. It had taken more than 16 hours, it emerged later, for the Queen’s brief communication to be clearly received in Newfoundland, though mysteriously the operators there managed to send the same message back the other way for verification in only 67 minutes. Throughout September communication was slow, error ridden, and untrustworthy. Days went by when nothing came through.

Ordering an investigation, the board of the Atlantic Telegraph Company managed to pry Whitehouse from his station in Valentia. Thomson and others took over, to try to reconstruct events and see if the project was salvageable. When he had handed over cable operation at the beginning of August, Thomson had been receiving clear signals on his sensitive mirror galvanometer. Whitehouse immediately connected his own equipment—heavy electromechanical receivers of standard design for overland telegraphy, requiring large currents. To supply those currents, he hooked up a gigantic induction coil (a kind of transformer) five feet long, supplied by a series of powerful battery cells, and yielding up to 2,000 volts. This, Whitehouse believed, would be more than enough to blast signals from Ireland to Newfoundland, and eventually, by brute force, he got the Queen’s message through. But he could detect no reply.

Then, at least in some accounts, he substituted Thomson’s sensitive galvanometer, began to receive signals from across the ocean, but had an assistant manually feed the messages into one of his own devices, so he could sent printed strips to London that appeared to come from his receiver. This was why the Queen’s message traveling back from Canada came through so quickly—it was received by a mirror galvanometer, though Whitehouse pretended otherwise.

For Thomson and the others, sifting through the wreckage of

Whitehouse’s miscalculations and deceptions was dismal work. Writing from Ireland to his friend James Joule at the end of September, Thomson contrasted his initial enthusiasm with the subsequent disappointment. “Instead of telegraphic work, which, when it has to be done through 2,400 miles of submarine wire, and when its effects are instantaneous exchange of ideas between the old and new worlds, possesses a combination of physical and (in the original sense of the word) metaphysical interest, which I have never found in any other scientific pursuit—instead of this, to which I looked forward with so much pleasure, I have had, almost ever since I accepted a temporary charge of this station, only the dull and heartless business of investigating the pathology of faults in submerged conductors.”

Learning what had really happened at Valentia during August and September, the directors fired Whitehouse. But the damage was done. Probably there had been a partial fault in the cable, a flaw in the insulation hundreds of miles from the Irish end. This was the old cable, hastily manufactured to a poor design for the 1857 expedition, then stored through the following winter in tanks of water at Plymouth. The following summer Field wrote to Thomson to say that on examining some cut-up sections of the cable that he had sold to Tiffany’s in New York as mementos, he found that in places the copper wire was distinctly off center, in some cases almost piercing through the gutta percha to the surrounding layer of tarred hemp. “I should like much to know to what cause you attribute these imperfections. What is in your opinion the cause of the Cable ceasing working?” he asked. Thomson speculated that the gutta percha had been applied too hot or that the cable had been bent before it had properly cooled. Whether winter storage of the cable had caused additional problems he could not say.³

A pair of electricians tested samples of the cable with the huge voltages that Whitehouse had applied. A section with perfect insulation, submerged in seawater, suffered no harm when they applied thousands of

volts to it. But when they made a pinprick hole in the gutta percha and repeated the test, “the interior of the jar lit up as if it were a lantern” and the hole in the insulation burned out big enough to put a thumb in.

In all likelihood the 1858 cable had too many imperfections to have lasted long. But Whitehouse’s unauthorized experiments and desperate application of larger and larger voltages undoubtedly brought it to a premature end. Naively, Thomson at first tried to defend Whitehouse, telling the board he had acted unwisely, as it turned out, but not maliciously. But the directors, who had now seen close to £2 million drowned and lost forever, were beyond magnanimity. One director wrote sternly to Thomson: “I must not hide from you that the course you took in relation to our recent difficulties with Mr Whitehouse added greatly to our troubles … & I am therefore much pleased to find that you are at length convinced that we acted wisely in dismissing Mr Whitehouse…. This great undertaking has been jeopardized & perhaps ruined by placing the electrical department in the hands of a man so inefficient, selfish & unscrupulous.”

Thomson learned his lesson. Perhaps, despite all his misgivings about Whitehouse, he clung to the belief that a man of science must necessarily be honest and sincere. Even after their first dispute, Thomson had thought about proposing Whitehouse as a fellow of the Royal Society. Honest disagreement was how science made progress. Thomson could believe that Whitehouse genuinely thought his telegraph system superior; he could not grasp that Whitehouse resorted to trickery because he could not bear to be upstaged by some young, unworldly academic. Eventually, faced with direct evidence of Whitehouse’s dishonesty, Thomson blinked a couple of times before he could believe it. But believe it he did, in the end.

The dispute burst into the correspondence pages of the London Times, Whitehouse attacking the board and Thomson, and the directors responding in kind. Thomson wrote privately to all parties, making clear that Whitehouse was now telling falsehoods—in particular, he claimed that the president’s reply to Queen Victoria was received on one of his devices, whereas in fact it came through Thomson’s mirror galvanometer. Official statements from the Atlantic Telegraph Company made plain their confidence in Thomson and utter distrust of Whitehouse.

Even so, Whitehouse did not entirely lose his reputation. He acted as consultant to Glass, Elliott in the construction of a Mediterranean line from Malta to Alexandria in 1861. But that was his last involvement with telegraphy. He returned to Brighton and died there in 1890, at the age of 73.

After the jubilation of 1858 turned sour, rumors began to fly that the whole thing had been a hoax from the outset, a scheme by which Field could unload his expensive shares on innocent investors. Even so, prospects for another cable attempt did not immediately fade. But on returning to the United States, Field found the economy in a downturn and politics uncertain as the country headed toward civil war. In 1859 he was in England again, trying to win government support for another venture. But even his powers of persuasion were now inadequate. In New York a disastrous warehouse fire put his old paper business on the road to bankruptcy. Then came secession and war.

In Glasgow in early 1859, at a city banquet celebrating his contribution to the cable, Thomson sounded a heartening message of Victorian optimism and the inevitability of progress. “The foundation of a real and lasting success is securely laid upon the ruins which alone are apparent as the result of the work hitherto accomplished…. What has been done will be done again. The loss of position gained is an event unknown in the history of man’s struggle with the forces of inanimate Nature.” Thomson may have firmly believed that the obduracy of nature could be overcome, but Field had to contend with money and politics. It was some years before an Atlantic telegraph again engaged anyone’s attention.

***

Thomson’s urgent effort to introduce quality control into the manufacture of commercial copper wire came up against numerous obstacles, not the least of which was the absence of any standardized procedure for measuring electrical conductivity or its inverse, electrical resistance. There was at that time no scientific unit of resistance, nor indeed of voltage or current. Galvanometers, including Thomson’s ultrasensitive mirror galvanometer, did not strictly speaking measure electric currents. Rather, a current passing through the device made a needle or a light beam swing, but how much it would swing in response to a given current varied from

one instrument to another. So, for example, one sample of wire could be said to have twice the resistance of another when, if both were connected in circuit with the same battery and galvanometer, the needle swung to half the amplitude for the first sample as for the second. (Though the underlying science was still fuzzy, it had been established that a given type of battery, say a zinc and a copper electrode immersed in an acidic solution, always produced the same electric potential, or voltage. The standard household battery produces 1.5 volts for this reason.)

The inability to perform accurate electric measurements mattered little for overland telegraphs covering modest distances. Either they worked or they didn’t. Engineers most often tested for a signal by touching a tongue to the bare wire: An ordinary battery produces a titillating tingle. But submarine telegraphs, as Thomson more than anyone knew, displayed a spectrum of intermediate conditions between working clearly and not working at all. Sporadic failures of the insulation could let some of the current trickle into the ocean. Variations in temperature or pressure might alter the capacitance of the cable, influencing both the strength and the timing of emerging signals.

Telegraph engineers learned a number of tricks for locating faults in an underwater cable. The simplest case was an outright failure such that the sea came into contact with bare copper, effectively earthing the wire at some unknown position. A known voltage applied at the shore end would pass some current down the wire as the electricity ran to ground at the fault. The greater the current so produced, the smaller must be the resistance of the wire it was passing through, therefore the closer the fault must be to the shore. At first, engineers used the method of comparison. They kept beside them miles of cable, coiled up, so as to compare the resistance of the faulty cable to some known length of wire. This was hardly convenient, especially when dealing with thousands of miles of underwater cable. Some absolute standard of resistance, and equally important some way of measuring resistances against the absolute scale, became increasingly necessary.

This problem fell naturally into Thomson’s range of interests. He had already proposed an absolute way of measuring temperature, based on Carnot’s theory of engines. In 1851 he had brought before the English-speaking scientific world his expanded and revised version of a sys-

tem of electrical units proposed on theoretical grounds by Wilhelm Weber in Germany. Still, it took his involvement with telegraphy to fully convince him of the need for practical measurement systems based on sound scientific principles.

Weber showed how to connect electrical phenomena with the familiar system of mechanical measurements by using Coulomb’s inverse square force law. Electric charge can be measured according to the force produced between two equal charges at a known separation. Current is the rate at which charge flows down a wire. According to Ohm’s law, enunciated by Georg Simon Ohm in 1827 though previously hinted at by many others, the current flowing down a wire is equal to the voltage applied divided by the wire’s resistance. But if you only know the current, there are two unknowns: you would know the voltage if you knew the resistance, and vice versa, but if you don’t know either, where do you start?

Thomson, expounding Weber’s ideas, filled in this gap by using one of his friend Joule’s early results. Joule had shown that the heating produced when electricity flows down a resistive wire is proportional to the product of the voltage and the current—what we now call the power of the electric flow. This gives an independent relationship between current and voltage, and allows resistance to be defined in an absolute, mechanical way—that is, using only measurements of force and energy.

Theoretically neat though it may have been, this so-called electrostatic system of units did not lend itself to practical application. There was no way to manufacture electric charge in reproducible amounts, and in any case the unit of charge implied by the metric unit of force over a separation of one centimeter was enormous, orders of magnitude bigger than anything encountered in the laboratory or the telegraph room.

Weber had also set out an alternative system, based on the force between magnets rather than charges. Permanent magnets were no more standardized or controllable than static electric charges, but Weber observed that a current passing through a coil of known dimensions would create an electromagnet that would feel a measurable force from the earth’s magnetic field. Here was the prospect of a more practical system: A coil could be made with some possibility of sameness from one laboratory to the next, and the earth’s magnetic field was at least approximately the same everywhere, once allowance for the laboratory’s latitude had been

made. The force produced on an electromagnetic coil therefore offered the chance of creating a standardized electric current, by which any scientist anywhere could in principle calibrate a galvanometer.

So elaborate a procedure, difficult enough for laboratory scientists, was far beyond the expertise of the telegraph engineers and technical men who actually needed standard measurements. At the 1861 British Association meeting in Manchester, the veteran telegraph engineers Charles Bright and Latimer Clark made a plea for the adoption of standardized measures that telegraphers had devised. Their voltage standards took the form of known electrochemical battery cells, which always produced the same potential, while their resistance standards were approximately reproducible pieces of metal. The German scientist M. H. Jacobi had in 1848 made in his laboratory a number of lengths of copper wire whose resistances, so far as he could measure with a cell and galvanometer, were identical. These he distributed to his colleagues throughout Europe, though they never found widespread use. Charles Wheatstone’s favored unit of resistance was a one-foot length of copper wire weighing 100 grains which, if well made, would have a fixed and uniform cross section. Werner Siemens, on the other hand, argued for the use of a column of mercury contained in a glass tube one meter tall and one square millimeter in cross section. For none of these units was there any scientific or rational justification. They were just convenient, or equally inconvenient, as far as telegraphers were concerned.

Bright and Clark wanted the BA to bestow an official imprimatur on one or more of these standards. But the scientists of the BA, aware of the scientific as well as practical importance of choosing units, assembled a committee to look into ways of devising a system that was generally applicable but also had a sound theoretical foundation. Clark disliked the way his and Bright’s initiative had been taken out of their hands. In the Electrician, the world’s first journal of electrical engineering, Clark voiced his concern that “the gentlemen who constitute the Committee … are but little connected with practical telegraphy, and there is a fear that while bringing the highest electrical knowledge to the subject, and acting with the best motives, they may be induced simply to recommend the adoption of Weber’s absolute units, or some other units of a magnitude ill adapted to the peculiar and various requirements of the electric telegraph.”

This was unfair. Thomson, who more than anyone combined theoretical understanding with direct experience of telegraphy, took a leading role, and the committee included practical men such as Wheatstone and Joule, as well as more refined theorists such as the young James Clerk Maxwell. Nevertheless, Bright and Clark refused at first to serve on the committee, though they joined after a year or two. Their eagerness to take part had been deflected when the nascent committee, at Thomson’s urging especially, agreed to use Weber’s magnetic system as a theoretical foundation and refer any practical measurements, such as the telegraphers preferred, to these absolute standards. Even when applied science and engineering had hardly moved out of infancy, distrust and wariness already existed between the academics and the practical men.

Tension developed at the 1861 BA meeting in part because Thomson, a friend to both sides, was not there in person. Just before Christmas the previous year he had been amusing himself on the ice at Largs with the Scottish game of curling, when he had fallen badly and broken his left leg. The local doctor diagnosed a fracture, but the supposedly more expert physician summoned from Glasgow claimed it was only a sprain of some sort and recommended bed rest with frequent application of hot bandages. A week of this treatment produced no improvement, and when a third physician came from Edinburgh and pronounced Thomson to have broken his leg after all, near the top of the thigh bone, irreversible damage was already done. The leg was set as best it could be, with Thomson repeatedly under chloroform for the pain. He was on his back for many weeks, and only by Easter of the following year was he able to hobble about on crutches. Eventually he recovered, but his left leg remained an inch and a half shorter than the right, a lameness somewhat concealed by the way he would dart about at great speed, his left hand pressed to his hip.

Unable to come to Manchester for the BA meeting, Thomson communicated his views on units in letters to a young engineering colleague, Fleeming (pronounced Flemming) Jenkin. Thomson would perhaps have been able to soothe and charm the telegraphers Bright and Clark, but Jenkin had a tendency to lecture. We would know little of Fleeming Jenkin except that an account of his life came to be written by none other than Robert Louis Stevenson. In the late 1860s Stevenson, son and grand-

son of the Stevensons who made a name for themselves building lighthouses, attended Edinburgh University ostensibly to become an engineer. For this he had no interest or aptitude and went to classes only to idle about and make jokes in the back row. Jenkin, then professor of engineering, brooked no such unseemliness in his lecture room. “At the least sign of unrest his eye would fall on me and I was quelled,” Stevenson recalled. “Such a feat is comparatively easy in a small class; but I have misbehaved in smaller classes and under eyes more Olympian than Fleeming Jenkin’s. He was simply a man from whose reproof one shrank.”

Stevenson cut the class altogether but struck up a friendship with Jenkin through a common interest in amateur dramatics. At the end of the session he had to obtain certificates for his classes, which he generally was able to seduce from his professors whether he had attended their lectures or not. But Jenkin resisted. “You see, Mr. Stevenson, these are the laws and I am here to apply them,” said Jenkin. “I could not say but that this view was tenable,” Stevenson observed, “though it was new to me.”

Eventually Stevenson wangled his certificate even out of the obdurate professor, and he came to admire the man for his rectitude, though he could be forbidding on first acquaintance. “He seemed in talk aggressive, petulant, full of a singular energy; as vain, you would have said, as a peacock,” Stevenson wrote of Jenkin. But on closer acquaintance he proved honest and rational, always ready to engage in serious discussion. He also turned less severe and judgmental as he got older, but when he attended the 1861 BA meeting as Thomson’s unofficial deputy, he was only 28 years old and full of the righteousness of a new convert to the world of scientific engineering. He had come to Thomson’s attention a few years previously, when he was working at R. S. Newall in Birkenhead, near Liverpool, overseeing the manufacture of the Atlantic cable. He had earlier sailed with John Brett on the cabling voyage from Sardinia to Africa.

Jenkin, careful and assiduous, strove to instill the notion of quality control in technical manufacturing as insistently as Thomson had done. They were natural allies. Before the 1861 BA, Jenkin had already made an effort to measure the insulating properties of samples of gutta percha systematically, instead of throwing lengths of cable into a tank of water, applying a current, and trying to detect electrical leaks, as had been the

usual practice. A failure of insulation too small to show up in such crude tests might nevertheless cripple a 2,000-mile undersea cable.

Thomson impressed upon Jenkin the importance of understanding electrical tests in a sound theoretical way as well as through experience. To men such as Bright and Clark, these niceties seemed like needless fussiness. No doubt they were eager to adopt practical guidelines and move on, but no doubt too they rather feared the intrusion into their livelihoods of scientific principles they could not follow. Telegraphy was the foundation of electrical engineering as a profession before it became an academic subject. (The modern British Institution of Electrical Engineers began life in 1871 as the Society of Telegraph Engineers.) Neither Bright nor Clark nor Jenkin had any formal university education in the technical applications of electrical science; no such course was available to them. Instead, they learned some mathematics and physics and picked up engineering principles on the job, as apprentices, just as William Thomson’s older brother James had done. They had, often, the difficult pride of the autodidact. Scientific rationalization of electrical units, minor matter though it may seem now, threatened to take away from the pioneers of telegraphy control of the subject they had invented.

On the other hand, Werner Siemens’s column of mercury was making headway on the continent as a resistance standard, and if the engineers and scientists could agree on one thing, it was that British units should rule the world. Thomson came up with an ingenious extension of Weber’s method that made the magnetic system into a feasible basis for practical definitions. He mounted a circular wire coil so that it could rotate around a vertical axis. At the center he suspended a small permanent magnet, hanging horizontally like a compass needle. With the coil stationary, the magnet lined up with the earth’s field. When the coil rotated, its wires cutting through the lines of the terrestrial magnetic field, a current began to flow, creating a secondary or induced magnetic field that acted to twist the small magnet. With the coil rotating at constant speed, the magnet shifted to a new stable position, in the modified magnetic field it now experienced. The clever and elegant result, Thomson proved, was that the deflection of the magnet depended only on the dimensions of the coil, its resistance, and its rate of rotation. Because both the direct and induced forces on the central magnet depended on the

earth’s magnetic field, the position at which these forces cancelled didn’t depend at all on the strength of the field, which was only approximately known. The need to know the earth’s field was the great defect of Weber’s original proposal. Thomson’s solution got around that problem.

Maxwell, by this time professor at King’s College in London, oversaw experiments to establish a British Association unit of resistance using Thomson’s method. It was important to get the length of the wire accurately, without stretching, which Maxwell and his collaborators did by unwinding the coil and laying the wire into a convenient groove between long floorboards at the laboratory. In Weber’s magnetic system, resistance turns out to be measured in the same units as a velocity,⁴ and the BA settled on 10,000 kilometers per second as its unit, this being a convenient magnitude for measuring resistances encountered in day-to-day work. The pedantically correct unit would have been one meter per second or one centimeter per second, depending on which of two competing metric systems one chose, but either one would have been an impossibly tiny amount of resistance. This was the drawback to Weber’s theoretically elegant structure.

At the 1863 BA meeting, committee members announced that they had produced a single physical sample, the so-called June 4 standard, with a resistance measured at 107,620 kilometers per second—in other words, a little over 10 BA units. Over the next few years they produced half a dozen such standards, made of platinum-silver alloy, all with slightly different resistances but measured, so it was claimed, to good accuracy. In fact, discrepancies among these standards, as well as in comparison to Jacobi’s old standard, to resistances that Weber himself had made, and to the mercury column favored by Siemens, existed at the level of five percent or more for many years.

By virtue of the BA’s scientific influence as well as the leading role that British manufacturers played in the telegraph industry, the BA unit

became by the late 1860s the de facto standard. In Paris in 1881, by force of intellectual power as well as personal charm, Thomson led a successful effort at the first International Conference for the Determination of Electrical Units to win official adoption of the BA definition as the universal standard.

Even with Thomson’s innovation, however, calibrating resistances on the absolute scale proved troublesome. As long as different BA standards varied by a few percent, the practical utility of the system was questionable. Engineers did not have the means to calibrate resistances themselves; use of Thomson’s method demanded high experimental expertise. Siemens, attending the Paris conference, insisted stubbornly and not without reason that the BA standard was all very well from an intellectual standpoint but of little help for engineers. He continued to push hard for his mercury column, on the grounds that it was easily defined and reproducible in simple laboratories. Adopting the BA unit on the admission that its precise value had yet to be determined was, Siemens insisted, a strategy bound to cause more confusion than it resolved.

It happened that Werner Siemens had a younger brother, Wilhelm, who had gone to London as a young man to market an electroplating method that the two of them had developed. There he fell under the spell of Britain’s entrepreneurial culture, though not without a hard assessment of its detractions. He wrote to his older brother: “I have had the opportunity to hear much about the character of the Englishman and have arrived at the conclusion that it is composed of pure egoism; an Englishman, for example, does not feel any shame in deceiving another person and there is no greater triumph for him than to hoodwink a foreigner, especially a German…. Yet as a people they are great, because they are free; and the people in Germany cannot imagine what freedom is. When I have lived here for a full year, I will be spoilt for Germany for the rest of my life.”

So it was. He stayed in England, became a British citizen, anglicized his name to William, took up telegraphic and electrical engineering in earnest, and became an acquaintance of William Thomson. He too was at the 1881 Paris meeting, as was Thomson’s great friend Helmholtz. Debate over the resistance standard came to a stalemate, with Siemens mustering a good deal of support for his position. The chairman of the

session, not wanting the effort to end in deadlock, adjourned the public discussion. A smaller group reconvened in the salon of a hotel, where deal making commenced. William Siemens persuaded his brother into a compromise by which he accepted the theoretical superiority of the BA definition, along with a firm commitment that his mercury standard would be calibrated and approved for practical use.

This was on a Saturday evening. Names for the units had still to be chosen, and national pride from many quarters demanded satisfaction. In their original proposal to the BA, Bright and Clark had suggested galvat (from Luigi Galvani, discover of “animal electricity” in frog’s legs) for current; ohma (Ohm), for electromotive force or electric potential; farad (Faraday) for electric charge; and volt (Alessandro Giuseppe Volta, who invented the electrochemical battery) for resistance. Clark transformed these into galvad, ohmad, farad, and voltad, and suggested that a millionfold of these units should be named galvon, ohmon, faron, and volton. C. F. Varley, another veteran of the Atlantic cable voyages, wrote to Thomson suggesting ampère for the strength of a magnetic pole, in order to get a Frenchman into the picture, and added: “I object to Galvad because Galvani discovered next to nothing.” Varley also disliked Clark’s names for the multiples, on the grounds, among other things, that Fleeming Jenkin “writes so badly that … Ohmad and Ohmon will be confounded in indiscreet writing”—an objection, he noted, that also applied to himself and Thomson.

Issues of penmanship aside, the conferees at Paris succeeded in assuaging chauvinism while appropriately honoring certain scientists. In another late-night meeting over hot chocolate, Thomson and the rest settled on the modern system. Giving an official name to the colloquial BA unit they chose ohm, since it was Ohm’s law that clearly defined electrical resistance. Ampere got the unit of current (with Thomson insisting that the accent be dropped for international usage), volt became the unit of electric potential, and Coulomb, who had established the force law between charges, was honored with the unit of electrostatic charge. Farad turned into the unit of capacitance, a sort of secondary honor and arguably less than the man deserved. Thomson may have been thinking of Faraday’s early understanding of the role of capacitance in the retardation of undersea telegraph signals. But equally, Thomson never

wholly grasped the character of Faraday’s individual genius, so different from his own brilliance at mathematical problem solving, and therefore may have been disinclined to push for a greater recognition.

The compromise between the BA unit and Siemens’s mercury standard, along with the names of the basic measures, came to the conference as faits accomplis when it reconvened on Monday morning. Thomson and Helmholtz hammered the deal through, each smothering discontent from their own countrymen. The French had no axes to grind and were presumably happy to get two of the four basic units, ampere and coulomb.⁵

The 1881 meeting left the resistance standard in an unhappy state. The BA definition was theoretically sound but hard to put into practice, and neither the BA wire standards nor Siemens’ mercury column were good to more than a few percent. The BA program continued for some time to make better-quality standards. In 1884 a third international conference settled on a column of mercury 106 centimeters long and one square millimeter in cross section, at the temperature of melting ice, as equivalent to one ohm. (This was refined to 106.3 centimeters at a meeting in Chicago in 1893, by which time the numerous standards agreed to within 0.1 percent.)

Speaking to the Institution of Electrical Engineers in London in 1883, Thomson portrayed the saga of the BA unit as a victory in the long term, with the mercury standard an interim solution until the wrinkles were worked out. Thomson’s effort in setting electrical measurements on a trustworthy theoretical foundation represents one of the most influential if little known achievements of his career. In no other person did experience of telegraphy combine with profound knowledge of elementary principles, still less in anyone as energetic, articulate, and forceful. Latimer Clark, who had at first doubted the necessity for the principles Thomson espoused, came eventually to see their importance. Writing the evening before his 1883 lecture to remind Thomson, in case

it had slipped his mind, of his and Bright’s original suggestions, he concluded: “I was not mathematical enough to see the enormous value of an absolute system, founded on mass, time, & space. It is this which has gained for the British system of Electrical Measurement its universal acceptance by mankind.”

***

Jenkin revered Thomson so much that his young wife, Annie, feared meeting the great man. She imagined “Professor Thomson as an aged and severe philosopher and rather dreaded an introduction to him. One evening I was sitting reading by the lamplight, when I heard hurried steps coming up the stairs: the door opened and in came a tall, fair-haired young man, who, not waiting to be announced, said with a most radiant smile, ‘Where is Fleeming? Are you his wife? I must see him. I am William Thomson.’ I saw for the first time that benevolent bending of his eyes on the person to whom he spoke that always remained and increased, I think, with the years. But the splendid buoyancy and radiance, which made me say to my husband when he came in later, ‘I have had a visit from Professor Apollo,’ I never saw again. It was in the following winter that Professor Thomson met with the accident which lamed him for life.” This was in 1859, when Thomson was only 35 years old but already a powerful figure in the British scientific community, an authority on every aspect of physics, and with the beginnings of a public reputation after his adventures with the Atlantic cable voyages and the noisy dispute with Whitehouse.

The business of telegraphy claimed an increasing part of his life. Always rushing hither and thither, Thomson had never been one for slow cogitation, and now had no time for it anyway. If he could solve a problem in a few hours, as he had done when learning from Stokes of the submarine cable difficulties, then solve it he would. If not, he would put the matter aside until he could spare an hour or two at some later date. While laid up for months with his broken leg he had overseen researches at Glasgow by sending letters, often several a day, to his technical assistant, Donald M’Farlane, demanding a detailed account of the results of yesterday’s experiments and ordering the next series to be done at the instant. During this convalescence he kept beside him a green notebook,

whose pages he rapidly filled with mathematical ideas, experiments to be attempted, drafts of papers, and any other technical thoughts that came to him. For the remainder of his life he never went anywhere without a green notebook and would pull one out on his numerous train journeys between Glasgow and London, at home during a lull in the conversation, in the middle of dinner, or when someone was speaking directly to him.

In the early 1860s the Jenkins lived in London. Thomson frequently went there on cable business and would squeeze in a visit to his friends. “I say we dined hurriedly,” Annie Jenkin recalled, “because [Thomson] always did, or seemed to me always to do, everything at topmost speed. When he came, it was always in a hansom cab, in front of which he stood, urging the driver on and guiding him by pointing his stick to our house, the address of which he never could learn though he came thither constantly, and when he went he was whirled away just in time to catch some mysterious train which started for Glasgow at the earliest possible hour in the morning.” As he became more busy and more famous, he would send a message to the stationmaster in Glasgow that he wanted to catch the last train to London, and the stationmaster would delay it until Thomson got there, clutching a green notebook as he hurried from cab to carriage.

His scientific publications proceeded apace, but their character changed. He wrote numerous short notes on problems of telegraphy, on the properties of copper and other conductors, on varied phenomena in electrical induction and transmission and the like, on the mechanical stresses on a cable dangling from the end of a ship, and so on. He had even, in 1852, presented to the Glasgow Philosophical Society his idea for a double-piston machine that could both heat and cool air for domestic purposes; this was a kind of heat pump, an antecedent of systems that have become popular in recent years for home heating and air conditioning. The great themes of his youth—the nature of electricity and magnetism, the foundations of thermodynamics—sank from view. In Germany, Clausius was polishing and refining his formulation of what would become known as the second law of thermodynamics, the law of increasing entropy, so that the significance of Thomson’s fundamental but not fully resolved contributions began to fade. At home, James Clerk Maxwell,

picking up on Thomson’s mathematical analysis and geometrical depiction of Faraday’s lines of force, began his long journey to a comprehensive theory of electromagnetism.

Everywhere in the natural philosophy of the mid-1800s, throughout the great systematization that became known as classical physics, lay the scattered evidence of Thomson’s brilliance and originality. Yet he never quite finished things off in a way that would allow history to judge him the true creator of any of the subjects he tackled. Telegraphy distracted him from real science—or so it is easy to think. But the cable did not pull him away, so to speak, of its own accord. He went willingly. He began to enjoy the company of engineers and men of business. His patent on the mirror galvanometer and other innovations brought him money. He received fees for consulting and advising on other projects. He traveled about the country at breakneck pace, mixing scientific with business meetings, flourishing in the world of commerce and enterprise.

In the dismal days after the failure of the 1858 cable, Thomson had written to Joule from the little telegrapher’s cabin at Valentia complaining of the drudgery of locating faults, but only after saying how, for him, transatlantic communication possessed “a combination of physical and (in the original sense of the word) metaphysical interest, which I have never found in any other scientific pursuit.” Telegraphy didn’t distract Thomson from science, in other words; it was for him what science was all about. He loved to solve problems, especially practical rather than philosophical ones. His contributions to electromagnetic theory and thermodynamics were in that vein. He saw how to reconcile opposing views and bring mathematical models in line with experimental and engineering reality. In devoting so much time and energy to the creation of a system of electrical units, he brought high principles to bear on empirical questions, and he helped engineer an international solution. Science for science’s sake could never have been Thomson’s motto. He was not, in that sense, an intellectual but rather an astonishingly clever and brilliant man. The point of science was to make things happen, to get things done, to resolve puzzles and difficulties. Above all, Thomson was good at that.

***

With the embers of the American Civil War barely cooling, Cyrus Field mustered support and money for a new Atlantic cable venture with remarkable alacrity. Although the Atlantic Ocean remained unbridged, submarine cables of increasing length had been laid with growing reliability in other parts of the world. By 1862 the Gutta Percha Company had manufactured some 9,000 miles of insulated wire. Glass, Elliott had put down dozens of underwater telegraph links, including a 1,500-mile section from Malta to Alexandria and a 1,400-mile connection across the Persian Gulf, part of a chain that gave London instant contact with India. A number of British financiers and entrepreneurs became interested in the Atlantic project, but as Thomson said later, “Cyrus Field, from the other side of the Atlantic, helped keep it alive; he gave help and impulse where they were required; worked with those who did not require revivification; and he, with his English colleagues, revived the undertaking in 1865.”

In 1859 the British government had set up a formal parliamentary inquiry into the failure of the 1858 cable. During 22 hearings over a period of nine months, testimony came from scientists, engineers, oceanographers, manufacturers, and electricians. Latimer Clark provided a thorough account of the necessary properties of insulators and conductors and of the testing of cables, both during manufacture and when in use. Whitehouse returned to provide his own dissenting views of the operation of submarine cables, but Thomson and Wheatstone succeeded in portraying him as a man out of his depth in this new technology.

The parliamentary inquiry, in a massive and detailed report that stands even today as a model investigation of a technological enterprise, concluded, in short, that the Atlantic connection was unquestionably feasible but that the 1857 and 1858 attempts had been hasty and cavalier in their lack of attention to technical and engineering essentials. From a modern perspective, this is stating the obvious, but in those days the whole panoply of research and development, of feasibility studies and cost-benefit analyses, of prototypes and field tests, had hardly been thought of, let alone systematized. The first Atlantic cabling ventures had been driven by enthusiasm and a sense of adventure, even wonder, more than by hard-headed planning. As Werner Siemens commented after the success of Brett’s English channel cable, “With the perseverance charac-

teristic of the English in prosecuting their undertakings … the laying of a large number of other cables was at once planned and attempted, before the problem was ripe for a scientific and technical solution. Failures accordingly could not but occur.”

By the mid-1860s, however, as Field rounded up his resources again, cable manufacture and laying had become practiced if not mature technologies. It was still an uncertain business, but it no longer seemed exotic. Even so, the Atlantic project had dissenters. Colonel Taliaferro P. Shaffner, formerly of the Union Army, had acquired some expertise in stringing telegraph lines around the interior of the United States and refused to believe that the 1858 cable had ever really worked. “A line of two thousand miles cannot be successfully operated for telegraphic purposes…. I express my opinion, that not ten consecutive words were ever sent through the cable in any one hour after it was laid,” he declared in 1859. He won support from the governments of Denmark, Sweden, and Norway for a line that would run in sections from Newfoundland to Labrador to Greenland to Iceland to the Faroe Islands to Scotland and finally to Norway, the longest submerged section being about 600 miles between Greenland and Iceland. At each landfall messages would be received and sent on to the next, a reasonable strategy except that it required permanently manned stations in each of the desolate intermediate spots.

Shaffner didn’t quite say that the direct link from Ireland to Newfoundland would fail, but speaking in 1859 to the merchants of Glasgow, Thomson’s hometown, he suggested that “to operate a line of that distance would require men such as Faraday and your Thomson—men of the very highest science. But when they are gone, where will you find their equals to succeed them?” This missed the point, of course. Thomson’s goal was always to enlist technology in support of systems that ordinary men could operate with confidence. In his history of the subject, Charles Bright credited Thomson’s improved mirror galvanometer as an essential factor in the ultimate success of the telegraph to India. Such developments pleased as well as enriched Thomson. Science itself might be the domain of experts, but the products of science ought to make life easier for the everyday engineer. That was exactly why he had battled so hard to bring a rational system of electrical units into general use.

With thanks due in large part to Thomson, the electrical part of submarine telegraphy, even across the Atlantic, had ceased to be a major concern. The most likely cause of electrical failure was damage to the fragile gutta percha insulation, but improvements in the design and manufacture of iron outer coverings allowed Thomson, speaking at a meeting in London in 1861, to look forward to a time in the near future when “a submarine telegraph cable would be designed, constructed, and laid, with the same prospect of success and permanency as a bridge, or a railway.”

It was getting the cable over the stern of the ship and safely down to the seabed that continued to pose the greatest difficulties. Enthusiastic amateurs suggested suspending an Atlantic cable from buoys so that it ran only 50 or 100 feet below the surface, or even dangling it from an array of hot-air balloons to avoid the water altogether. But by the time Field had organized a new Atlantic cabling voyage in 1865, engineers had developed impressive cabling machines, yards long, with drums and pulleys and tensioners, that allowed the crew to let the cable out at a controlled rate and, more important, pick it up again smoothly when a fault had been detected.

The most obvious change in the new expedition was that a single ship now carried the entire tonnage of cable. This was the Great Eastern, the vast, ill-starred creation of the renowned English engineer Isambard Kingdom Brunel, who had intended the vessel as a passenger and cargo ship that could travel from Britain to Australia on a single charge of coal. On one of his early trips to England, before the first cabling attempt, Field had met Brunel on the train from Bristol to London, Brunel being the builder of that track and the founder of the Great Western Railway Company. Learning of Field’s project, Brunel had taken him out to the east of London, where the almost 700-foot-long hull of the unfinished Great Eastern loomed over the marshy Isle of Dogs. “There is your ship,” he told Field, but not until September 1859 was the giant vessel floated, with difficulty, onto the shallow waters of the Thames estuary. Brunel only once, and briefly, saw his fondest creation moving under its own power. He suffered a stroke two days before the ship’s launch and, partly recovered but feeble, saw it begin sailing into the English Channel. A few days later there was a disastrous explosion, killing a number of people

and destroying the forward funnel. The great ship limped on. Brunel died on September 15, a few days after being told of the tragedy. He was only 53, a small, intense, combative man brought down, it was said, by a lifetime of financial struggles and commercial rivalries.

The Great Eastern plied fruitlessly back and forth across the Atlantic for a few years. The owners had difficulty finding enough passengers and cargo to make the voyages profitable, and on one of the first occasions when it appeared they might make some money, the ship ran aground off Ireland, incurring costly repairs. A few years later she was holed in Long Island sound, and the cost of repairs bankrupted its owners. By 1864 the Great Eastern was idle, in the hands of bondholders to the tune of just £100,000—a ship that had cost more than £1 million to build. Daniel Gooch, a railway engineer turned magnate and former colleague of Brunel, joined with a few colleagues and bought the ship at auction by buying out £25,000 of bonds for cash, with the holders of the other £75,000 agreeing to take shares in the new company.

Gooch had not long before this become a director of the newly formed Telegraph Construction and Maintenance Company, an amalgamation of Glass, Elliott with the Gutta Percha Company. He now struck a deal with Cyrus Field and the Atlantic Telegraph Company. In return for £50,000 in ATC shares, he agreed to use the Great Eastern to lay an Atlantic cable, with his company bearing all operating costs and handing the cable over to Field only after a successful voyage. The ornate ballrooms and luxurious cabins of Brunel’s great ship were stripped out, leaving a cavernous space that was divided into three enormous tanks suspended within the hull on massive timbers. “It presents the appearance of a dead forest, all the trees of which have been roughly trimmed,” wrote one young man who worked a cabling voyage. “Huge beams stretch in all directions, vertical, horizontal, and diagonal, tiring the eye by their similarity and numbers, and giving an idea of almost unnecessary strength.”

The delegation of cable-laying operations to Gooch’s company left Thomson and the other technical members of Field’s team in an awkward position. The chief electrician for Field was C. F. Varley. On the 1865 voyage, in the words of a journalist, Varley “was ordered by his board not even to give his advice if he were asked for it, unless the de-

mand were made in writing, and in that case he was only to answer in writing, and to insert in the written document a distinct declaration that the opinion given was not in any way to bind the company which he represented. Professor W. Thomson of Glasgow, whose name is known over Europe, and who is certainly one of the most distinguished and acute physicists in the world, was admitted on board as a sort of scientific aide-de-camp to Mr Varley, but he was not to depart from the course indicated by the board to his principal. So there were two gentlemen, full of suggestions and ideas and formulas, reduced to silence—two great guns, spiked as it were, but charged to the muzzle…. In the gravest discussion they held no part. The only way in which they could give utterance to their feelings was by asking questions.”

The 1865 attempt almost succeeded. Soon after the expedition left Ireland on July 23, the electricians detected a fault in the cable that had just gone overboard, and the ship was brought to a halt to allow retrieval and repair. A splinter of sharp iron was found piercing the insulation, from core to exterior. Splicing out the damaged section, the crew resumed their tasks. Then a few days later exactly the same thing happened again. Now there was talk of sabotage. Under questioning, the crew all swore their devotion to the project. Watchmen were posted to oversee the uncoiling of the cable from the holding tanks up onto the deck, through the paying-out machinery, and into the sea. Then a little later an alert crewman saw, as the cable wound around one of the drums, a splinter of brittle iron separate from the outer covering and lodge in the machinery. He removed it before it could do any damage, and the mystery was solved. “What we had taken for assassination might have been suicide,” as one commentator put it.

The Great Eastern plodded serenely on through heavy seas, “steady as a Thames steamer,” the cable unreeling smoothly over the stern. About two-thirds of the way across, 600 miles from Newfoundland, detection of another fault brought the ships to a halt. As the crew prepared to reel the last few miles of cable back in again, the rolling sea caused it to chafe gently against the ship’s side. Conditions were not bad, and work was proceeding smoothly, when a slight change of the wind or an unusual swell made the ship heave momentarily in a different direction. Without warning, the cable snapped and disappeared below the waves. The shock

was abrupt and stunning. “I will never forget this hour or the effect it had upon all engaged. Had we been one family and just lost a dear father or mother, our faces could not have worn a more down cast expression,” Daniel Gooch wrote later.

Cabling crews had by this time learned to retrieve lost wires by dragging a grapple across the seabed, but the lost cable of 1865 lay 2,500 fathoms down, in some of the deepest waters of the Atlantic Ocean. Nevertheless, they grappled four times and hooked up the cable on three occasions, only to find that their ropes and tackle were not strong enough to pull it all the way to the surface. They had to give up because every time the grappling line broke, they lost hundred of fathoms of it, and finally did not have enough to make another attempt.

After this “sad and dreadful discouragement … we were all dispirited in a sense, but not discouraged,” Thomson said later. “I remember well a night in the cabin of the Great Eastern, when the enterprise of 1865 was finally seen to be a failure that the rest of us wished to go to bed and sleep in discouragement after the labors of a fortnight. But Field would not sleep until he had the prospectus elaborated which led to success.” The cable had shown no electrical problems. The paying-out machinery had worked well. The attempt could have been successful had the planners thought to include stronger lines for picking up the lost cable, and more of it. This they would be sure to do next time.

Field only briefly returned to the United States before coming to Britain again at the beginning of 1866, to Thomson’s great relief. “I am very pleased to learn that you are again in this country. You are not come too soon as the [Atlantic Telegraph Company] seems to require your impulse and I am sure will be much the better for your presence,” he wrote. For legal and financial reasons, Field started up yet another company, Anglo-American Telegraph, which he quickly floated for £600,000. On Friday, July 13, a foggy as well as inauspicious day, the Great Eastern set off once again from Ireland. Apart from a stoppage to unravel a tangled section of cable, the voyage proceeded uneventfully. On the morning of July 28 the tiny fishing village of Heart’s Content came into view, Thomson and the others on the Great Eastern having maintained unbroken contact with Valentia. The cable end was landed and hooked up. Announcements traveled down the wire to New York and London. Con-

gratulations pulsed in from San Francisco and Alexandria, Egypt, and places in between, all now part of a seamless telegraph network.

There was little of the wild exuberance that had broken out in 1858. International telegraphy was not exactly routine, but it lacked the immediacy and novelty it had possessed eight years earlier. The British, this time, seemed more excited than the Americans. The Atlantic cable had become almost entirely a British project, in money and technology and ships, except for the essential presence of Cyrus Field—who, because of his close ties to Britain and Britain’s unconcealed support for the south during the Civil War, attracted some criticism and dissent in American newspapers for an excess of anglophilia.

After just a few days the flotilla headed to sea again in an attempt to pick up and complete the 1865 cable. Thomson and some of the other engineers had devised a plan by which three ships would drag for the cable and pull it up part way to the surface, distributing the immense weight on three grappling lines. Still it took weeks for the plan to succeed. Dropping a line to the seabed took two hours; hauling it up again, with or without a cable at the end, took several more. After a number of excruciating near successes, the lost cable end was dragged aboard the Great Eastern early on the morning of September 2 and hooked up to the electrical room. Back in Valentia, operators at length noticed the flickering light of a mirror galvanometer on the long-dead cable, and cheers erupted in Ireland and in the middle of the Atlantic Ocean as messages of confirmation passed back and forth.

Now there were two transatlantic lines, and commercial telegraphy began in earnest. Old shares of the Atlantic Telegraph Company finally began to pay dividends. The cables of 1865 and 1866 lasted, in fact, only a few years. By late 1870, both had failed forever. But by then there was a cable from France to Newfoundland, and so profitable was this business that by the mid-1880s a dozen cables crossed the Atlantic Ocean.

Thomson, who had traveled on five cabling voyages to Newfoundland and back without direct payment, started earning money from the licensing of his patents for the mirror galvanometer, which all telegraph operators used. His expertise was rewarded with contracts to advise on other cable projects around the world. Letters from lawyers and patent agents in subsequent years reveal sums of hundreds or a few thousands of

pounds coming to Thomson in license fees for patents he owned outright or shared with men such as Jenkin and Varley—this at a time when £200 a year was a substantial middle-class income.

As well as wealth, there came public recognition and official honor. At the age of 42, in honor of his extended efforts in bringing the transatlantic cable to reality, Thomson became Sir William Thomson. To his colleagues in the academic world, it might have seemed that he had abandoned his true calling, but so far as Sir William was concerned, the technology of the telegraph was science in action. There was nothing lowly or shameful about it. Speaking in 1874 as president of the Society of Telegraph Engineers he declared that “in no other branch of engineering, indeed, is high science more intelligently appreciated and ably applied than in the manufacture and use of telegraphic lines.”

Thomson saw no fundamental distinction between his scientific analysis of undersea cables and his earlier analysis of Carnot’s heat engine, which had led him to the foundations of thermodynamics. He could pass from one to the other and back again without feeling he had transgressed any intellectual boundaries. He had no interest in becoming a financial magnate, a pure entrepreneur. With the pioneer days of global telegraphy coming to an end, Thomson’s interest naturally reverted to old concerns and brushed up against new ones.