by Seth Shulman
Like the liquid transmitter, Bell’s magneto transmitter design used a vibrating diaphragm, but it operated on a different principle. Rather than using the vibrating diaphragm to vary the electrical resistance in the circuit, the diaphragm vibrated in front of a magnet to cause tiny fluctuations of the current in the magnetic field. It was, in essence, a telephone receiver in reverse: rather than using fluctuations in electric current to trigger vibrations of sound waves in the air, Bell realized he could make the sound waves induce tiny changes in a magnet’s residual electric current.
The method yielded a terribly weak signal, but Bell nonetheless had adopted the method wholeheartedly by late April 1876. By May, all mention of the liquid transmitter in Bell’s laboratory notebook had ended. Only then, with this alternative transmission method in hand, did Bell finally make a public announcement of his invention of the telephone.
In 1966, Bernard Finn, a curator at the Smithsonian Institution, tested some of the museum’s collection of Bell’s transmitters and surmised that Bell might have switched away from the liquid variable resistance transmitter because the magneto design worked better. Finn’s hypothesis is intriguing, but Bell’s notebooks offer no evidence that he was displeased with the performance of the liquid transmitter, or that his new method achieved any improvement. On the contrary, Bell notes that it is difficult to hear consonants with the early versions of his magneto transmitter.
Even if Finn’s conjecture is accurate, it still does not adequately explain Bell’s complete abandonment of the variable resistance transmitter. Bell surely recognized that the signal in his magneto transmitter was exceedingly weak, whereas the variable resistance transmitter’s signal could be easily amplified. This crucial advantage would make it possible to transmit speech over long distances. Electrical researchers, including most notably Thomas Edison, would soon make the need for liquid obsolete by using carbon in their variable resistance transmitter designs. But it was the liquid, variable resistance transmitter which first crossed the vital technological threshold, opening the door to virtually all modern telephone transmitter designs.
Viewed with hindsight, the irony is that Bell took a marked step backward in his transmitter design, moving from a primitive version of the variable resistance model that would become the industry standard to a magneto-electric design that would quickly become obsolete. As Bell’s biographer Bruce notes,
Upon the variable-resistance transmitter, drawing power from a readily expansible source, the future telephone industry would rest. Bell saw its great advantage clearly enough. Yet by the end of April [1876] he had drifted away from it and back to the magneto transmitter, which depended on the puny power of the sound waves themselves to induce its current.
Nonetheless, having finally succeeded in transmitting speech—months after the fact—with a telephone design that comported more closely with the language in his patent, Bell went public. He announced his success in his lecture at the American Academy. And he actually demonstrated speech transmission several days later, on May 25, 1876, before a good-sized audience at MIT.
With help from the staff of the MIT Archives, I retrieved the handwritten minutes from the MIT meeting at which Bell appeared. This time, unlike his speech at the American Academy, Bell demonstrated the speaking telephone in action. A brief report in the Boston Transcript notes that vowel sounds came through Bell’s telephone device, but that consonants were all but “unrecognizable.” Notably, at this landmark event, Bell demonstrated only his magneto-electric transmitter; the liquid, variable resistance transmitter was nowhere to be seen.
Once again, the evidence, while circumstantial, all pointed toward one conclusion. On March 10, 1876, Bell crossed a momentous threshold and he knew it immediately, writing to his father on the night of his success that he had “at last found the solution of a great problem.” Plus, he already held a patent protecting his invention. In public, however, Bell made absolutely no mention of the circumstances surrounding his initial success. Then, when Bell did finally unveil his speaking telephone publicly, he demonstrated only his second, and likely inferior, transmitter model. Why? A close look at Bell’s actions strongly suggests that he sought to conceal the fact that his telephone breakthrough came using a liquid transmitter design. Under the circumstances, there is little doubt that Bell wished to hide this incriminating information—especially from Elisha Gray.
It seems likely that, despite Bell’s success in March with the liquid transmitter, he waited to go public until he had found an alternative transmission method he could reasonably claim as his own. Bell no doubt hoped that, by featuring the magneto transmitter, he could present a plausible and seemingly independent path to the telephone that would dispel any hint of foul play. If so, Bell’s plan would be put to a particularly nerve-racking test on June 25, 1876. On that date, Bell had to demonstrate his telephone and explain his research to an international group of telegraph experts and dignitaries that included Gray himself.
15
PARTY LINE
LATE INTO THE night on Wednesday, June 21, 1876, Alexander Graham Bell sat awake in a gaslit room at Philadelphia’s Grand Villa Hotel, writing a long letter to his fiancée, Mabel Hubbard. He was too excited and nervous to sleep. Bell had traveled to Philadelphia to exhibit his telephone at the International Centennial Exposition, an enormous world’s fair held to commemorate the nation’s one hundredth anniversary. Shortly after his arrival, Bell told Mabel, he had learned that the Centennial’s eminent panel of judges—including Britain’s Sir William Thomson (later Lord Kelvin), one of the world’s most respected electrical researchers—expected Bell to demonstrate his invention that coming Sunday.
A month earlier, Bell had given two well-received talks about his research to rarefied academic audiences in Boston, but the stakes here in Philadelphia, amid the fanfare of the exposition, were far higher. Hubbard, ever the enterprising businessman, had insisted that the reluctant Bell unveil the telephone to the public at the exposition because of the event’s size and global audience.
On this point, Hubbard’s judgment was astute. The Centennial Exposition was truly a grand venue for such a technological debut, affording a level of visibility virtually unobtainable elsewhere. More than 30,000 exhibitors were displaying their wares in 190 buildings on the 250-acre site in Philadelphia’s vast Fairmount Park. Over the course of its six-month run, the exposition would draw an astonishing 10 million visitors from around the world.
Bell had arrived in Philadelphia two days earlier, on June 19, and, like the throngs of other visitors, he had marveled at the exhibition’s offerings from the moment he visited the fairgrounds. As he wrote Mabel:
I really wish you could be here, May, to see the exhibition. It is wonderful! You can have no idea of it till you see it. It grows upon one. It is so prodigious and so wonderful that it absolutely staggers one to realize what the word “Centennial Exhibition” means. Just think of having the products of all nations condensed into a few acres of buildings.
Some thirty-seven nations had sent examples of their handiwork, from European paintings and sculpture to Chinese porcelain and carved jade. One of Brazil’s contributions, an ornate, solid-silver, two-ton table, particularly caught Bell’s eye. Venezuela’s exhibit featured a portrait of George Washington that had purportedly been woven from the hair of Simon Bolívar, the Venezuelan revolutionary leader who was revered as a liberator throughout South America. Prominent among such international offerings was the French sculptor Frédéric Bartholdi’s dramatic, unfinished statue of a huge hand bearing a torch. This massive work-in-progress, several stories tall and hand-fashioned from copper, stood outside with its own small pavilion near the center of the exposition. For a small charge, visitors could walk into the statue and climb to the base of the torch. They were also asked to donate ten cents apiece to allow Bartholdi to complete his wildly ambitious project. It would take another decade, but the arm and torch would eventually sit atop Bartholdi’s monumental Statue of
Liberty, an ode to America that found its permanent home in New York Harbor in 1886.
MORE THAN ANYTHING, though, the Centennial Exhibition was a showcase for the burgeoning age of invention and, in particular, for American machinery and ingenuity. The Centennial boasted the world’s first steam-driven monorail system and even a newfangled elevator on Fairmount Park’s Belmont Hill—it could carry forty people at a time to the top of a 185-foot-tall observation building for a bird’s-eye view of the grounds.
In the vast Machinery Hall, the latest technology was on display in all its Gilded Age splendor. Visitors most likely got their first-ever glimpses of sewing machines and typewriters, not to mention a staggering array of projection lanterns, fire alarms, lathes, and firearms. A vast row of locomotive engines on display gave way to a colossal 70-foot-tall, 1,400-horsepower Corliss Steam Engine whose 56-ton flywheel commanded the hall. The giant steam engine powered all the exhibits in the building through five miles of overhead belts, shafts, and pulleys. Even beyond its impressive function, though, the engine stood as a potent symbol for the entire exhibition. As one correspondent colorfully noted, it rose
loftily in the center of the huge structure, an athlete of steel and iron with not a superfluous ounce of metal on it; the mighty walking-beams plunge their pistons downward, the enormous flywheel revolves with a hoarded power that makes all tremble.
It was no wonder that inventors, craftsmen, and representatives from leading manufacturing companies of all kinds came to display their products. Edison brought his newly designed duplex telegraph, able to send two messages at once. Rudolph Koenig of Paris, whose name I remembered thanks to my colleague Dave Pantalony’s special interest in him, had set up an elaborate exhibit to display his unrivaled scientific tuning forks and other acoustic devices. The New York firm of Bausch & Lomb offered an impressive display of optics, from eyeglasses to hand telescopes and binoculars. Another prominent exhibit touted the extraordinary heat resistance of a brand-new material called asbestos. And, in the fair’s restaurant section, a Pittsburgh pickle merchant named Henry Heinz introduced the public to a new tomato condiment.
Bell must have recognized that the Centennial represented an unmatched opportunity to display the fruits of his research, yet his correspondence reveals a person racked with trepidation as his moment in the spotlight drew near. As Bell curiously complained to Mabel, for instance:
I shall be glad when the whole thing is over. I wish the whole telegraph were off my hands altogether.
Bell’s tone is certainly not what one would expect from someone who, with a U.S. patent firmly in hand, was about to unveil a remarkable and unprecedented invention to the world. While it is understandable that Bell would be nervous before his performance, his hand-wringing comes across as more than simply a matter of last-minute jitters.
Bell had resisted the idea of displaying the telephone at the Centennial Exposition ever since Gardiner Hubbard had suggested it months earlier. First, Bell missed the application deadline; Hubbard, undaunted, used his influence with the Centennial’s organizing committee to allow Bell to participate anyway. Then, Bell continued to refuse to go to Philadelphia; but Hubbard made his case to Mabel, who took the matter into her own hands.
Ultimately, in an episode that would become part of Bell family lore, he left for Philadelphia under the most remarkable circumstances. As Bell’s daughter Elsie recounted much later, Mabel, after much fruitless cajoling to get Bell to attend the event, finally resorted to a ruse: she persuaded him to accompany her on an innocuous-sounding “drive in the family carriage,” only to whisk him to the train station and hand him a suitcase that she had surreptitiously packed with his belongings.
Bell, stunned, still declined to get on the train, but Mabel burst into tears and threatened not to marry him if he didn’t go. As Elsie tells the tale, Mabel (who was of course deaf) turned her head away so she couldn’t hear Bell’s protests in retort. In his own version of events, Bell explains in a letter to his mother from New York the next day that he grudgingly boarded the train at the last possible moment because he couldn’t bear to see Mabel so “pale and anxious.”
The incident explains why Bell wrote Mabel upon his arrival in Philadelphia:
My darling May:
Fate has brought me here against my will and now she seems determined to keep me in spite of myself…. [I] feel that I am here for your sake and at your device.
For her part, Mabel acknowledged that the episode had been hard on her, too. As she put it:
It was very hard to send you off so unwillingly but I am sure it was for the best and you will be glad of it by and by. Don’t get discouraged now. If you persevere, success must come. Anyway it will be a great help to you to be connected with scientific men.
Still, the circumstances explain how Bell got to Philadelphia against his will, but not why he was so set against the idea in the first place. Most of Bell’s biographers, taking his protestations literally, have explained his reluctance to exhibit his telephone in Philadelphia as a consequence of his dedication as a teacher, noting that it was an inconvenient time for him to leave his students. True, it was near the end of the semester, but, as it turned out, Bell was back in time for final exams. However dedicated he might have been to his students, it is difficult to imagine that leaving them for a few days would have caused him such consternation.
Similarly, Catherine MacKenzie suggests that Bell’s reluctance stemmed from the fact that he had missed the deadline for entering his device into the exhibition and did not want Gardiner Hubbard, who served as part of the Massachusetts delegation to the Centennial, to have to use any influence on his behalf. As MacKenzie recounts,
Mr. Hubbard assured him that it would be the merest detail to add the apparatus to the earlier exhibit. In his official capacity nothing could be easier to arrange. To Bell, whose literal honesty never made concessions, the thing was impossible. If he could not comply with the rules, he would make no exhibit.
This, too, seems like an inadequate explanation. Even a cursory look at the emotional tone of the correspondence during Bell’s visit to Philadelphia suggests that considerably more was going on.
Upon closer inspection, it seems apparent from Bell’s many references in letters to his parents, and to Mabel, that a major cause of concern was the presence at the exposition of none other than Elisha Gray, who had come to demonstrate his own multiple-messaging telegraph at the prominent Western Union exhibit. Although the two men had never met, Bell kept close tabs on the inventor he considered his rival and surely knew that Gray had been in Philadelphia for over a month readying his exhibit.
Bell’s concern appears to have reached a level of near panic when the Centennial’s judges asked him to demonstrate his devices on Sunday immediately following their review of Gray’s instruments. The prospect of such a juxtaposition realized Bell’s worst fears. As he explained to Mabel in his confessional, late night letter from the Grand Villa Hotel:
I must say I don’t like this at all…. I feel very nervous about it—for I feel I have come on here very hurriedly without sufficient preparation to be thrown into direct collision with Mr. Gray [emphasis added].
Although Bell would often worry, his level of apprehension and foreboding, like his reluctance to attend the exposition in the first place, stands glaringly at odds with the exciting promise of his circumstances. Bell was a natural orator and performer. It is hard to interpret anything other than guilt and panic in his dark brooding on the eve of his Centennial demonstration. Why else would he write to Mabel that he felt “very hopeless” and “heartbroken” just as he was about to showcase the greatest success of his life? Bell even frets to Mabel that
If I don’t make a change and very soon—Telegraphy and Visible Speech together will be the end of me—and then we shall never be married at all.
What kind of change was Bell seeking to make? And what exactly was he saying would lead to his demise? The florid hand-wringing in his correspondence do
es not let on. But Bell’s mood is revealing, and so are his actions. He surely wanted to impress the judges with his demonstration any way he could. And, to that end, the telegraphic equipment sent to Philadelphia on Bell’s behalf included the liquid transmitter that he had used with such success when he first transmitted speech. With Gray present, though, how could Bell display his transmitter, or even reveal a hint of its existence? Little wonder Bell was nervous: he faced not one but two daunting tasks. He had to display a working telephone to the judges and convince Elisha Gray that he had invented the telephone independently. Only then could he hope to walk away from the exposition with his reputation, his sole claim to the telephone, and his engagement intact.
AFTER BELL HAD prepared and made adjustments for several days, the dreaded Sunday, June 25, arrived. The judges had chosen that day to review Gray’s and Bell’s telegraphic equipment because the exposition was closed to the public, affording relative quiet for the acoustic demonstrations. The morning proved to be not just quiet—it was also swelteringly hot, especially inside the glass pavilion of the main hall where the formally attired delegation of fifty scientists and dignitaries gathered. Among them, only the gregarious and rotund Dom Pedro II seemed relatively unruffled by the heat.
At the Western Union exhibit on the center aisle of the main hall, Elisha Gray gave an impressive demonstration of his harmonic telegraph, which simultaneously transmitted a remarkable eight messages over one wire. More comfortable as an engineer than an orator, Gray had brought with him Professor George F. Barker from the University of Pennsylvania to offer additional theoretical explanations for his devices. To great acclaim from the judges, Gray also demonstrated his musical telephone. Transmitting from several hundred feet away, Gray played a rendition of “Home, Sweet Home,” which came through clearly even over the gasps of excitement and amazement from the distinguished audience.
