Empires of Light

by Jill Jonnes

  When Parisian professor of mathematics André Marie Ampère read of Oersted’s experiments, he was highly skeptical. Ampère, a deeply religious man whose personal life was bedeviled by disastrous marriages and delinquent children, sought solace in mathematics, chemistry, and science. Ampère readily replicated Oersted’s work, then proved that the strength of the magnetic field intensified with the rise of the power of the electric current. Ampère also showed that currents flowing parallel in the same direction attract each other and currents flowing in opposite directions repel. Over the next decade, this new understanding—that a current-carrying wire created a magnetic field around it—led to the creation of ever more powerful electromagnets. In Albany, New York, American engineer and inventor Joseph Henry was one of the pioneers. He used his wife’s old silk dresses to insulate wires, enabling him to wrap more than one coil around a piece of iron. The more layers of coils, the more powerful the electromagnet. This work would earn him a professorship at Princeton University. Henry, who later became the first head of the new Smithsonian Institution in Washington, D.C., devised gigantic electromagnets by wrapping hundreds of feet of insulated electrical wire around huge horseshoe-shaped pieces of iron. Demonstrations with these odd-looking instruments elicited thrilled gasps from audiences, for these electromagnets could lift loads as heavy as a ton. Yet despite all these advances in the understanding of electricity, it had few useful applications.

  Oersted’s discovery of electromagnetism and Ampère’s expansion of that work generated a deluge of fresh electrical research and an ensuing avalanche of new scientific articles. At the Royal Institution near Piccadilly Circus, the assistant Sir Humphry Davy had hired back in 1813, Michael Faraday, had become England’s foremost analytical chemist, a man renowned for his brilliance, originality, hard work, gentle nature, and sheer scientific productivity. (Many would later say that Sir Humphry’s greatest scientific contribution was hiring the unknown Faraday.) Though Michael Faraday had evinced little interest in electricity, in the spring of 1821 the editor of the Annals of Philosophy suggested that Faraday apply his much admired intelligence to authoring a survey article on the new science of electromagnetism, thus luring the thirty-year-old philosopher into this fascinating and puzzling field.

  Faraday looked more like a poet of the Romantic school than a scientist, for he had a wonderfully handsome, gentle face with a high brow, dark, intelligent eyes, and a headful of thick, wavy curls parted in the middle. Faraday had not, like Oersted, come to science through a university. Indeed, his formal education ended at age twelve when he was apprenticed for seven years to a bookbinder. Faraday had completed his service and was just starting that career when a friendly customer bestowed upon him coveted tickets to Sir Humphry’s highly popular lecture series entitled “The Elements of Chemical Philosophy.” Faraday was so smitten by what he heard and saw at the Royal Institution that he amplified the exquisite notes he had taken during the quartet of talks, made numerous illustrations, compiled an index, and bound it all together into a lovely little book. This he sent along to his new idol, Sir Humphry Davy. Later Faraday would write, “My desire to escape from trade, which I thought vicious and selfish, and to enter into the services of Science … induced me at last to take the bold and simple step of writing to Sir H. Davy.”20 Sir Humphry, having risen to magnificent heights from his own humble beginnings, had been sufficiently impressed by the ambition, intelligence, and ardor of this twenty-two-year-old blacksmith’s son (and his jewel of a book) to hire Michael Faraday as his assistant. The job paid £100 a year, along with two upstairs rooms at the institution and a supply of coal and candles. So while Faraday was not a university man, he was ensconced in a prestigious and well-funded institute. Such was Faraday’s natural scientific brilliance that his discovery of benzene and related chemicals pioneered the way for the new and important aniline dye industry, even as he also advanced the liquefaction of gases. By 1824, he was a Fellow of the Royal Society. The next year, at age thirty-three, Michael Faraday was appointed director of the Royal Institution’s laboratory.

  Once he delved into the great mass of books and articles on electricity, trying to sort out what was important for his survey article, Faraday was thoroughly ensnared by the conundrum of this invisible force. By 1822, Faraday had written in his laboratory notebook, “Convert magnetism into electricity.”21 He tried on four occasions during the 1820s, even as he was making stunning breakthroughs in chemistry, to figure out some means for converting magnetism to electricity, but he was stymied. Then, on August 29, 1831, Faraday, dressed as ever in his plain black cutaway coat, high-waisted pants, high collar, and plain cravat, noticed a weird effect that provided the vital electrical clue.

  Faraday had an iron ring. On one side he had wound a coil of insulated wire that was attached to a battery. On the other side of the ring he wound a second coil of insulated wire, and that was attached to a galvanometer, which measures small electric currents. When Faraday activated the battery to electrify the first coil, he looked hopefully for signs of life in the second coil but saw none. What did catch his eye was that the galvanometer registered a feeble and momentary current when the battery was attached or detached. Here was the first clue: A change in the charged coil’s magnetic field—starting and stopping it by activating the battery—briefly created current in the second wire coil. Faraday’s friend and colleague John Tyndall would later ponder Faraday’s genius and explain it thus: “He united vast strength with perfect flexibility. His momentum was that of a river, which combines weight and directness with the ability to yield to the flexures of its bed. The intentness of his vision in any direction did not apparently diminish his power of perception in other directions; and when he attacked a subject, expecting results, he had the faculty of keeping his mind alert, so that results different from those which he expected should not escape him through preoccupation.”22 Faraday had registered those tiny movements on the galvanometer.

  Over the next couple of months, as autumn brought the usual rain and gloom to London, Faraday found a day here and there to pursue these intriguing blips by the galvanometer. In his first experiment, he wound a coil of wire around a straight iron core. He took two long bar magnets and held them in a V and used the wrapped iron core as the third side of the triangle. When the V of the magnets was separated, breaking the magnetic circuit, current was induced in the coil. Noted Faraday in his laboratory journal, “Hence, distinct conversion of Magnetism into Electricity.” To further test this, he took a pencil-shaped magnet and simply moved it in and out of coiled wire. The moving magnetic field created a brief current in the wire. But Faraday was interested in producing a continuous current, not just brief bursts.

  So he set up a simple twelve-inch copper disk on an axle that revolved between the opposite poles of a permanent magnet. On one side of the copper disk, a wire ran from the axle to a galvanometer. Then another wire led from the galvanometer to a metallic conductor held against the rim of the copper disk. When the copper disk revolved, disturbing and thus changing the magnetic field of the magnet, the galvanometer registered a continuous electric current. Wrote Faraday in his minutely detailed laboratory notebooks, “Here therefore was demonstrated the production of a permanent current of electricity by ordinary magnets.” Simply stated, Faraday’s law of electromagnetic induction says that an “electric current is set up in a closed circuit by a changing magnetic field.”23

  Faraday modestly described his epochal discovery of the world’s first electric dynamo as “A New Electrical Machine” in a paper before the Royal Society in London on November 24, 1831. Oersted had shown how to create magnets with electricity, while Faraday had revealed the other, even more mysterious and momentous half of electromagnetism, how to generate electricity with magnets. As marvelous as was Michael Faraday’s further deciphering of electricity, no one at the time envisioned its extraordinary ultimate consequences, for who could imagine that this was the foundation of the modern electrical industry? Unlike V
olta, who largely rested on his laurels after inventing the battery, over the next decade and a half Faraday’s “almost intuitive insight into many of nature’s secrets” led him to elucidate on electromagnetic lines of force and the relationship among electric current flow, the magnetic field, and motion through that field. He showed that simply by changing the magnitude of current flow, you caused change in the magnetic field, and that in turn caused current in any conductor in the magnetic field. Faraday would also clarify the electrochemical nature of electricity, determine the specific inductive capacities of many materials, establish a relationship between light and magnetism, and resolve the long debated question of whether the electricity produced by lightning, electrostatics, batteries, and his generator were all the same invisible entity. They were.24 As one biographer writes, “His versatility, originality, intellectual energy and sheer stamina leave us in awe.”25

  Faraday’s own life, work, and stature became an inspiration and model for successive generations of scientists. Believing that Sir Humphry’s wealth and titled eminence distracted from his wholehearted pursuit of science, Michael Faraday politely turned down time-consuming titles, opportunities to earn a fortune, and all the socializing attendant on honors and wealth. A devout member of the small Sandemanian Christian sect, he lived modestly, quietly, and happily with his beloved wife upstairs at the Royal Institution. But down in the basement laboratory Michael Faraday was a veritable lion, a passionate and brilliant scientist of rare energy able to select and focus on the most meaningful, discerning problems. His scientific output was prodigious and fundamental, influencing peers in many fields. His laboratory notebooks set a standard of beautifully observed detail, organization, and honest record keeping. The charm of his prolific writings—and his readiness to admit his many laboratory failures on the road to experimental success—earned him wide and enduring readership. His three-volume Experimental Researches in Electricity and Magnetism remains a classic.

  In the 1830s, with Sir Humphry Davy dead in 1829 at the young age of fifty-two, Faraday truly took over the running of the Royal Institution. One of his first acts was to inaugurate the Friday evening discourses, as well as special Christmas lectures for children. Faraday, whose whole life course was radically and joyfully altered by his attendance at Sir Humphry’s famously enthralling lectures, viewed these public events as highly important. Who could say which child might embrace a life of science after a Christmas lecture or which influential and enthusiastic member of the Friday night audience might decide to shower grateful guineas on the Royal Institution? In the age when laboratory science was truly coming to the fore, Michael Faraday was its greatest sage and prophet. He was fittingly also the institution’s most scintillating and mesmerizing speaker, his handsome face full of passion, hair flying poetically as he moved fluidly about to show his experiments before the packed amphitheater. The Friday evening lectures began promptly at 9:00 P.M. before an expectant, educated audience dressed formally as for the opera. Recalled one fan, “His audience took fire with him, and every face was flushed.”26 Faraday’s friend Tyndall wrote, “He exercised a magic on his hearers which often sent them away persuaded that they knew all about a subject of which they knew but little.”27 When the lecture ended promptly at 10:00 P.M., the animated audience drifted to the institution’s magnificent two-tiered library, there to imbibe refreshments, view an exhibition based on the evening’s topic, and marvel at science. Faraday’s 1849 Christmas lecture for children, “The Chemical History of a Candle,” is still read.

  Under Michael Faraday’s ardent leadership, the Royal Institution became one of England’s most important social and intellectual centers when that nation was powerfully ascendant, attracting many eminent Victorians and luminaries, including Charles Dickens, Charles Darwin, and T. H. Huxley. Wrote one Faraday biographer, “Such was the prodigality of his output and the diversity of his skills that modern chemists, no less than physicists, engineers, and material scientists, regard him as the founder of their subjects: some sciences and technologies owe their very existence to his work…. He bequeathed to posterity a greater body of pure scientific achievement than any other physical scientist, and the practical consequences of his discoveries have profoundly influenced the nature of civilised life.”28 Faraday was uninterested in spending his own time making anything specifically practical or useful. “A philosopher,” Faraday explained, “should be a man willing to listen to every suggestion but determined to judge for himself. He should not be biased by appearances, have no favourite hypothesis, be of no school and in doctrine have no master…. Truth should be his primary object. If these qualities be added to industry, he may indeed hope to walk within the veil of the temple of nature.”29 And so, dedicated to the higher calling of Truth, Michael Faraday had little patience for utility. After he had demonstrated a new chemical process or opened a new electromagnetic realm and the inevitable question followed, “What is its use?” Faraday liked to quote Benjamin Franklin, who had famously replied: “‘What is the use of an infant?’ The answer of the experimentalist is, ‘Endeavor to make it useful.’”

  In the ensuing years, scientists and inventors in England, Belgium, France, Germany, Italy, the United States, and every Western nation all mightily endeavored to make electricity useful, exerting their mental faculties to the utmost in the wake of Faraday’s magisterial work. Electroplating was at this time electricity’s one practical industrial and commercial application. However, batteries were steadily improving, so that by the 1840s electricity wrought its first miraculous revolution, becoming the basis for a workable telegraph. These middle decades of the nineteenth century saw remarkable, rapid technological advance, with steam engines, railroads, and the telegraph demolishing all traditional notions of power, space, and time. In these same years, coal-gas lighting became a cheap and convenient illuminant indoors in urban homes, offices, and some factories, displacing whale oil and candles. Distributed from a central gashouse to buildings and sidewalks via underground pipes—much the way water was—coal-gas lighting spread quickly in big cities. On cloudy or moonless nights, gas lamps now supplanted whale oil lamps on major metropolitan streets.

  The coming of gaslight, like the coming of the railroads and the telegraph, noticeably altered the aeons-old rhythms of time and place. “A new age had begun for sociality and corporate pleasure-seeking…. The work of Prometheus had advanced by another stride,” wrote Robert Louis Stevenson, singing the praises of gaslight. “Mankind and its supper parties were no longer at the mercy of a few miles of sea-fog; sundown no longer emptied the promenade; and the day was lengthened out to every man’s fancy. The city folk had stars of their own; biddable, domesticated stars. It is true that these were not so steady, nor yet so clear, as their originals; nor indeed was their lustre so elegant as that of the best wax candles. But then the gas stars, being nearer at hand, were more practically efficacious than Jupiter himself…. But the lamplighters took to their heels every evening, and ran with a good heart. It was pretty to see man thus emulating the punctuality of the heavens’ orbs.”30 Gas lighting proved as popular in American cities as it was in foggy London, and by 1875, there were more than four hundred gas lighting companies in the United States.

  As gas lamps replaced (or supplemented) the age-old light of oil and candles, and brought nocturnal lighting for the first time to many murky city streets, inventors and entrepreneurs struggled to come up with a workable version of the brilliant arc light Sir Humphry Davy had demonstrated to such acclaim in 1809. The British operated a few isolated and remote arc light lighthouses using large batteries, while a few daring and avant-garde members of the surviving French aristocracy tried them on their grounds. When engineers installed experimental arc lights near a château in Lyons, the local paper reported, “One could in fact have believed that the sun had risen. This illusion was so strong that birds, woken out of their sleep, began singing in the artificial daylight.”31 The arc light spectrum was indeed close to that of sunli
ght, and many commented on its evenness and steadiness, so unlike the flickering, swaying light produced by burning gas jets, oil lamps, or candles. But to become a commercial entity, the arc light needed a far simpler, better design and a practical electrical generator. While batteries served well enough for the minimal power needs of the telegraph and then the telephone, battery power was twenty times more expensive than that supplied by steam engines and certainly far too expensive a form of energy to compete with popular gas lighting.

  Creating a better generator was a deeply baffling task. It would be almost thirty-five years from Faraday’s epochal demonstration of his “electric machine” to the triumphant emergence of a truly practical dynamo. Many labored on the dynamo problem, but the man who ultimately prevailed “to make it useful” was Belgian engineer Zénobe-Théophile Gramme, who worked for a Parisian maker of electrical devices. By the early 1870s, Monsieur Gramme had not only designed a far more powerful direct current generator, but, equally important, had also invented the electric motor, which he showed was just a dynamo or generator running in reverse. Gramme incorporated a major advance introduced by Werner von Siemens: The bit of genius that propelled his generator ahead of all others was using electromagnets rather than regular magnets. A Gramme dynamo featured a ring of iron encircled by coils of wire that revolved in the plane of the lines of force between two electromagnets.

  With the Gramme dynamo in hand, the time was ripe for the arc light. And in 1876, Russian military engineer Paul Jablochkoff (also living in Paris) finally came up with a commercial version—the Jablochkoff “candle”—that cast a gentler light than the earlier, glaring arc lights. The “candle” paired two tall, thin carbon sticks separated by a layer of kaolin cement, which served as both insulator and binder. “No mechanism was required for operation; once started the carbons continued to burn until consumed, lasting about two hours. Clusters of candles were arranged so that when one burned down, another was automatically started up.”32 Unlike earlier arc lights, Jablochkoff’s could run for as long as sixteen hours, because as one pair sputtered out, another would take over.