After the burst of publicity set off by the demonstration of the incandescent lamp on New Year’s Eve, Edison spent the next twelve months getting the bulb ready for market. The lamp had to be transformed from a delicate, glass-blown curiosity into a mass-produced, commercial product that people could buy on a grand scale. Edison was still dissatisfied with the filament and spent much of the year searching for a new material that could be carbonized but still retain its structural strength.

As he had done with the cotton thread, he selected a material that was close at hand. One warm day, he picked up an old bamboo hand fan sitting on a nearby table and examined its fibrous structure. Thinking it might be a suitable replacement, he instructed his staff to test it as a source for filaments. Once carbonized and inserted into a lamp, the bamboo filaments burned as long as 1,200 hours - the best results yet. Edison immediately went looking for a supplier.

“Within a very short time,” wrote William Meadowcroft, Edison “sent a man off to China and Japan in search for bamboo. . . . The man did his work well and among the species of bamboo he sent was one that was found satisfactory. Mr. Edison obtained a quantity of this and arranged with a farmer in Japan to grow it for him and to ship regular supplies. This was done for a number of years, and during that time millions of Edison lamps were regularly made from that particular species of Japanese bamboo.”

Next, Edison had to tackle the challenge of mass-producing glass bulbs. Rather than exhaust his limited time and resources, he decided to subcontract the glass production to the Corning Glass Works in upstate New York. Ever the stickler for detail, Edison took the time to go to Corning to help design the process for manufacturing thousands - in years to come, hundreds of thousands of glass globes. To pump air from the bulbs, Edison came up with a way to mechanize part of the process. Even the lamp sockets, originally constructed of wood lined with copper strips, had to be redesigned, the wood ultimately replaced with plaster of Paris.

Edison also invented “safety wires” to prevent the lamps from short circuiting and starting fires, what we know today as fuses. By 1880, Edison was becoming more of an industrialist than an inventor, coordinating a complex enterprise and managing an ever-increasing workforce. Edison was determined to be in charge of producing the practical applications of his inventions. This policy put him at odds with some of his investors, especially the directors of the Edison Electric Light Company, who were interested in seeing a return on their investment as quickly as possible. Edison later admitted that his promise to have his power plant in New York up and running in a relatively short time had been unrealistic. He had made it, he said, “with a view to keeping up the courage of my stockholders, who naturally wanted to get rich faster than the nature of things permitted.”

Edison was trying to do many things at once, all of which required capital. At the time he was working on perfecting the light bulb, he also created America’s first electric locomotive, which he tested on a track he constructed at Menlo Park. The locomotive was far from perfect, but railroad magnate Henry Villard - owner of the Columbia - was so impressed that he gave Edison $40,000 for further research. Edison’s other investors were less benevolent; they worried about how much of their money he was spending. At one point, an inventor named William Sawyer and his partner, Albon Man, told the financiers they had the patents for an incandescent lamp and could mass produce it faster than Edison. The directors of Edison Electric Light decided to investigate Sawyer’s claim.

Edison was furious. He instructed Francis Upton to check out all the previous electric light patents. Unlike most of Edison’s assistants, Upton had a college degree and a year of scientific study in Germany. After examining numerous patents, British as well as American, and reading technical publications, he announced that “I feel sure that the total you have is new, no matter if parts of it have been used before.”

While perfecting the lamp, Edison was already focusing his energies and resources on a power plant and an electrical distribution system for lower Manhattan. Charles Clark, one of the newer engineers, was assigned to work on developing the dynamo; draftsman Julius Hornig was given the job of designing the buildings and machinery needed to produce the electricity.

But as the anniversary of his dazzling demonstration on New Year’s Eve 1879 approached, Edison still seemed years away from building the comprehensive system he envisioned. His backers were restive, and his rivals were challenging, if not infringing, on his patents.

In December 1880, Edison enjoyed a pleasant and surprising diversion when Sarah Bernhardt, the celebrated French actress, then on a tour of the United States, asked to meet “le grand Edison,” the man who had invented the phonograph. Late on a cold, snowy Saturday evening, Bernhardt took the train to Menlo Park, arriving at 2:00 a.m. Sunday morning. From the station, she and her companions bundled up in a horse-drawn carriage and made their way along pitch-black roads toward Edison’s home. As they approached the house, the entire area lit up.

“As quick as thought the whole country was suddenly illuminated,” Bernhardt recalled in her memoirs. “Under the trees, on the trees, among the bushes, along the garden walks, lights flashed forth triumphantly.”

In the wintry early morning hours, Thomas and Mary Edison, their children, and three of Edison’s assistants greeted the legendary actress. Bernhardt was immediately taken with Edison, noting his “wonderful blue eyes, more luminous than his incandescent lights.” She found him a “delightful but bashful savant.”

Edison gave Bernhardt a personal tour of his laboratory. “I followed him about quickly,” she wrote, “climbing up staircases as narrow and steep as ladders, crossing bridges suspended in the air above veritable furnaces, and he explained everything to me. I understood all, and I admired him more and more, for he was so simple and charming, this king of light.”

“C’est grand, c’est magnifique,” Bernhardt exclaimed at everything Edison revealed: the lab, the glass blowers’ quarters, the machine shop. “I looked at this man of medium size,” she wrote, “with a rather large head and a noble-looking profile, and I thought of Napoleon I. There is certainly a physical resemblance between these two men. . . . . Of course, I do not compare their genius. The one was destructive, the other creative.”

Edison was also entranced, so much so that he traveled to New York that winter to watch Bernhardt perform. It was a great compliment and a gesture of homage, since the nearly deaf inventor couldn’t hear much of what she had to say on the stage.

By this time, Edison was obsessed with getting his network in New York up and running. Here, he intended to prove that his electric lights would work in an urban setting. But first he needed the blessing of the city’s political leaders, many of whom had invested in the gas industry. Some of the aldermen suggested charging Edison a tax of $1,000 per mile to electrify a stretch of lower Manhattan. In late December, two weeks after Sarah Bernhardt’s visit, Lowrey persuaded Edison to invite New York Mayor Edward Cooper and the aldermen to Menlo Park for a lighting display, to be followed by dinner. The evening did not begin well. The conservative politicos had little to no interest in technology. Edison and his staff opened with an hour-long explanation of his plans for the distribution of electricity in New York and then led his guests into his darkened lab. As they stood in the blackness, he flipped a switch and the lab was aglow with burning lamps.

This dramatic ploy was followed by a superb dinner with champagne and cigars, supplied by New York’s fashionable restaurant, Delmonico’s. The food and drink may have made more of an impression than the science, but by the end of the evening, the politicians were much more impressed with Edison. “All in all,” the Herald commented, “Mr. Edison’s tests were a decided success, especially of his guests’ capacity for champagne.”

While the New York politicians debated granting Edison a franchise, Edison’s biggest obstacle was the short-sightedness of his own investors. The directors of Edison Electric Light considered their enterprise strictly a patent-holding company, one that made the bulk of its money from licensing the rights to those patents, not manufacturing light bulbs or building power stations.

Testifying at a patent lawsuit hearing ten years later, Edison recalled his frustration: “Wall Street could not see its way clear to finance a new and untried business. We were confronted by a stupendous obstacle. . . . The directors of the Edison Electric Light Company would not go into manufacturing. Thus forced to the wall, I was forced to go into manufacturing myself.”

In a small barn across from his Menlo Park lab, Edison built a factory to make incandescent light bulbs. He financed it himself, with contributions from some of his employees, including Upton and Batchelor, who became his partners in the enterprise. Within a year, more than 100 men were producing 1,000 bulbs a day. More factories followed. Edison sold some of his Edison Electric Light shares and used others as collateral to finance a facility in New York City that made lamp sockets, switches, and fuses.

But Edison didn’t have the financial wherewithal to build the biggest and most expensive components of his electrical system: power generators. Once again, he turned to his favorite patron, Henry Villard, and asked him to back his latest venture, Edison Machine Works.

In January 1881, Edison had the pieces in place to mount a large-scale test in Menlo Park that would demonstrate how his system would work in Manhattan. This time, the political leaders of New York were convinced. In April, they gave Edison Electric Light the go-ahead in Manhattan. Even his tight-fisted investors were impressed, advancing him another $80,000 to build a central power station.

With that, the Wizard of Menlo Park transferred his operations from the wilds of New Jersey to the frenzy of New York City. While he kept the Menlo Park lab and factory in operation, he took many of his senior employees and much of his equipment with him to New York. His new headquarters and showroom were located at 65 Fifth Avenue, in a four-story double brownstone in an upscale residential and business neighborhood. Edison rented Mary and their three children rooms in a hotel near Gramercy Park. It was a far cry from his days in Manhattan as a penniless former telegraph operator.

“We’re up in the world now,” he told a reporter. “I remember ten years ago - I had just come from Boston - I had to walk the streets of New York all night because I hadn’t the price of a bed. And now think of it! I’m now to occupy a whole house on Fifth Avenue.”

America’s elite came to see Edison’s showroom, including J. P. Morgan and William H. Vanderbilt, whose New York mansions Edison electrified. Still, the electric age got off to a rocky start. The lights at the Morgan and Vanderbilt residences frequently blew out. Neighbors complained about the racket made by the large dynamos, and the lights turned on and off at preset hours, interrupting dinner parties, balls, and card games.

The lights in Edison’s showroom and the financiers’ mansions ran on their own generators. But the real test of Edison’s theories would come when he set up a centralized power station and a network of transmission lines. To help him with this enormous task, Edison had a new protégé, twenty-one-year-old Samuel Insull, who had just arrived from London to be Edison’s private secretary.

Like Edison, Insull was smart, self-educated, and ambitious. He started out as a stenographer for Edison’s agent in Britain, Colonel Charles Gouraud. Intrigued, he learned everything he could about Edison and his European business ventures. When Edward H. Johnson, a member of Edison’s staff, went to London, he was surprised to find that the intense young man knew more than he did about Edison’s financial stake in Europe. Johnson decided Insull would be the perfect secretary for his boss. When he sent a cable to Insull asking him to come to the States, Insull booked the first available ship.

When Insull arrived in New York in the spring of 1881, Johnson immediately took him to Edison’s showroom on Fifth Avenue, where, after a formal introduction, Edison explained his current financial problems. His investors, he told Insull, had spent $500,000 bankrolling his inventions but now were refusing to supply the additional funds needed to manufacture them, or to finance the construction of central power stations to provide the electricity that would make the products practical. Edison told Insull he intended to back the enterprise with his own money.

Insull was struck by the enormity of Edison’s task. The inventor, Insull wrote in his memoirs, “was engaged in a gigantic undertaking.” Not only was he short of money, but he couldn’t find the machinery he needed. He was about to take over a large factory, and he planned to hire as many as 1,500 men in the next few months.

“Right after dinner,” Insull recalled, “Mr. Edison explained to me that it was necessary for him to start three or four manufacturing establishments to produce dynamos and lamps and underground conductors for his first district. He produced a wallet from his pocket, told me he had $78,000 to his credit at Drexel, Morgan & Company and asked me where he could get the balance.”

That night, Insull scrutinized Edison’s books and estimated the money the inventor might expect to make from selling his patent rights in various European countries. Edison could, Insull speculated, borrow against that anticipated revenue.

Like Sarah Bernhardt, Insull was beguiled by Edison’s charisma. “What struck me above everything else was the wonderful intelligence and magnetism of his expression and the extreme brightness of his eyes,” the young advisor wrote. Edison offered Insull a salary of $100 a month, with promises of more to come.

Insull’s duties were diverse. He might be charged with buying a new suit for Edison or to wake him up after a short nap. When Edison began constructing his central power station on Pearl Street in lower Manhattan, he sent Insull to conduct a survey of the number of gas burners in each house, so he could calculate the market for electricity in the neighborhood.

In the end, Insull assumed responsibility for virtually all of Edison’s finances. He managed to keep the company afloat by arranging credit and guiding Edison through the intricacies of patent cases. It was quite a juggling act: Insull was sometimes so short of cash he couldn’t pay the rent on Edison’s Fifth Avenue house.

During the 1880s, Edison formed nine companies to market his various inventions and projects. It was Insull’s job to keep track of the resulting financial complexities and to untangle them as he had Edison’s personal finances.

Insull worked for Edison for twelve years, the last six of which were spent managing the Edison Machine Works in Schenectady, New York. Sending him off, Edison said to Insull, “Do it big, Sammy. Make it either a big success or a big failure.” As always, Insull took Edison at his word. When he resigned in 1892 to build his own utility and railroad empire in the Midwest, the company’s workforce had grown from 200 employees to 6,000.