The Man Who Found The Universe In A Light Bulb

HIS WORK IS PART OF YOUR HOME, FOR he reinvented the light bulb in the form we use to this day. But that was just a start. His light-bulb work led him to vacuum tubes, and he improved the crude ones of his time, allowing colleagues to build the tubes that launched commercial radio broadcasting. Similar tubes produced X rays and brought important advances in medicine. Then, with his research taking wing, Langmuir developed the first techniques for measuring the sizes and shapes of atoms and molecules. He founded a new science, plasma physics. And, almost as an aside, he explained the periodic table of the elements, which had previously been entirely empirical, giving a theoretical interpretation that even high school students could carry in their heads.

Irving Langmuir spent his career at General Electric, and for decades he was a leader at the G.E. Research Laboratory, a pioneer among the nation’s centers for industrial research. His work at the frontiers of science melded with the company’s pursuit of new products, spurring the rise of the modern industrial laboratory by showing how studies in pure science could pay off handsomely. His studies won him a Nobel Prize, the first awarded to a scientist for work in industry.

Irving Langmuir was born in Brooklyn, New York, in 1881. His father had made a fortune in business, lost it all in a mining venture, and recouped by building a new career in insurance, rising to become a director for Europe of the New York Life Insurance Company. However, he continued to struggle financially, and Irving, along with three brothers, grew up amid adversity. Although he had very poor eyesight, Irving did not get his first pair of eyeglasses until he was eleven years old. When he did, he was amazed at what he had been missing—individual leaves on trees, for example. He would spend the rest of his life examining the world in greater and greater detail.

The Langmuir boys’ upbringing colored their lives with a sense of serious purpose. It also gave Irving a taste for overseas travel, as he spent three years in Paris as a youth. On vacations in the Swiss Alps he went mountain climbing, which became a lifelong interest.

An older brother, Arthur, studied chemistry and helped interest Irving in this field by setting up a small laboratory in the family’s basement. Another brother, Herbert, tutored him in science and soon found himself outstripped. On Irving’s thirteenth birthday his mother wrote to a friend, “Herbert says he fairly has to shun electricity, for the child gets beside himself with enthusiasm, and shows such intelligence on the subject that it fairly scares him.” Entering the Columbia University School of Mines in 1899, shortly after the death of his father, Irving took a degree in metallurgy in 1903. As he later explained: “The metallurgical engineering course was strong in chemistry. It had more physics than the chemical course, and more mathematics than the course in physics—and I wanted all three.” A professor of physics, R. S. Woodward, asked him what he wanted to do in his career. Langmuir replied, “I’d like to be situated like Lord Kelvin—free to do research as I wish.” This response touched a chord in the professor, who encouraged him to pursue further studies.

Langmuir knew that to follow in the path of Lord Kelvin he would need a Ph.D. The American universities of the day lacked strong graduate programs, so Langmuir went to Germany to work with the chemist Walther Nernst at the University of Göttingen. The decision was propitious. Nernst went on to win his own Nobel in 1920 for work in thermodynamics and was also an inventor who devised a light bulb that improved on Thomas Edison’s. These themes—academic excellence along with practical invention- would define Langmuir’s career just as they defined Nernst’s.

As a graduate student Langmuir used Nernst’s light bulb as an electrical test tube. The bulb contained a brightly glowing filament within a vacuum, and Langmuir took advantage of both these aspects. The filament reached high temperatures, and he studied the behavior of water vapor and carbon dioxide under those conditions by introducing small amounts of gas into the evacuated bulb. The work was routine, and he did it only because Nernst had assigned it to him. But the experimental techniques introduced him to procedures that he would apply with increasing subtlety for decades to come.

AFTER RECEIVING HIS DE gree in 1906, he took a job teaching chemistry at the Stevens Institute of Technology in Hoboken, New Jersey. It proved a sad comedown. He wrote in a letter that at first his students had “paid almost no attention, but talked to one another and threw hats etc. around the room.” A different group “brought in a couple of old broken bats and a baseball.” He dismissed the class. The next day “I could not turn around to write on the board without having them do such things as pull off each other’s shoes etc. so I dismissed them again.”

He finally brought his students under control and proceeded to teach them successfully, but he soon realized that he would not find his future in Hoboken, where he was saddled with a heavy load of courses and found little chance to do research. In contrast to his later career, when he might publish a dozen papers in a single year, Langmuir published only one between his 1906 doctoral thesis and his first paper at G.E. in 1911. In 1909, passed over for promotion and denied a raise, he decided to seek greener pastures. His new opportunity proved to lie up the Hudson River in Schenectady, New York, where General Electric was developing the nation’s first true industrial research lab.

G.E. stood in the forefront of the electrical industry, manufacturing light bulbs and other devices that had grown out of the work of Edison, whose company had been merged into G.E. in 1892. Edison had of course had his own research center, but he had largely relied on cut-and-try techniques and established scientific fact, disdaining fundamental studies that lacked an immediate payoff. “We’ve got to keep coming up with something useful,” he told his associates. “We can’t be like those old German professors who spend their whole lives studying the fuzz on a bee.”

At the turn of the century, those old German professors were giving G.E. a run for its money. G.E.’s position was impregnable in the field of Edison-type light bulbs, which used a carbon filament. But carbon evaporated readily and would not last long if heated above 2,900°F. At this temperature the carbon radiated much of its energy as heat rather than as visible light. Such bulbs wasted electricity, making them costly to use.

So there was considerable interest in other forms of electric lighting that might employ different types of filament or rely on new physical principles. By the late 1890s, twenty years after Edison had introduced his carbon filament, three such improvements were in prospect. All drew upon work by German specialists who had strong backgrounds in basic science, which Edison lacked.

Walther Nernst was in the vanguard. He introduced a filament of ceramic in the form of a thin rod, building lamps that were both more efficient and longer-lasting than the Edison type and required no vacuum. He patented his invention and sold the American rights to Westinghouse, G.E.’s strongest rival. Another German chemist, Carl von Welsbach, showed that a filament of osmium, a metal with a high melting point, could outperform carbon. A physicist in Berlin, Leo Arons, was building the earliest mercury-vapor lamps, with efficiency even higher than Nernst’s. Westinghouse invested money in this invention as well.

G.E. had its own in-house specialist, Charles Steinmetz. He appreciated the value of basic research, for he had carried out such work in dealing with alternating current, even introducing new mathematical methods for its study. In 1900 he proposed that company officials should respond to Westinghouse’s advances in electric lighting by setting up a research lab to pursue work in this field. Elihu Thomson, a founder of G.E., warmly agreed. He called for “a research laboratory for commercial applications of new principles, and even for the discovery of those principles.”

The idea of discovering new principles was novel, for in those days most inventors expected to learn of such discoveries from scientists at universities. However, Nernst, Welsbach, and Arons were demonstrating that academic investigators were not reluctant to descend from their ivory towers, hire attorneys, and head for the patent office. With university professors turning commercial, G.E. would have to protect itself by attracting scientists of similar caliber to its new General Electric Research Laboratory.

The nascent lab needed a director. Steinmetz wouldn’t do, because he had no interest in administration. The company found its man in Willis Whitney, a young chemist at MIT. Whitney had received his Ph.D. at Germany’s University of Leipzig, working with another eventual Nobelist, Wilhelm Ostwald. Back in the States, Whitney showed a strong penchant for studies of interest to industry. He gave a new and correct explanation for the rusting of iron in terms of chemical reactions similar to those within an electric battery. He also showed how to prevent corrosion by adding alkali to water. Turning to industrial consulting, he worked with the American Aristotype Company, a manufacturer of photographic supplies, and introduced methods for the recovery of valuable alcohol and ether, which had been going to waste. That company went on to merge with Eastman Kodak.

WHEN WHITNEY arrived in Schenectady in December 1900, he found that he would have to conduct his research in a barn that- Steinmetz had been using as his personal lab. The barn burned down the following spring, and Whitney and Steinmetz relocated to a small building within the G.E. facilities. Whitney tried to pursue basic research but did not get very far. He had better luck when he set out to devise an improved carbon filament. This invention helped hold off the competition from Westinghouse and put the lab in good favor with company officials.

Then in 1904 the Europeans struck again. At the firm of Siemens and Halske, in Berlin, the chemist Werner von Bolton introduced a filament of the metal tantalum. Its high melting point yielded efficiencies greater than those of Whitney’s best carbon lamps, and it could be produced at a modest price. That same year, two chemists in Vienna made filaments of tungsten, whose melting point topped 6,000°F, making it potentially even better than tantalum. Clearly the days of carbon filaments were numbered.

G.E. purchased some of the Europeans’ patent rights, but that was only a stopgap. It was up to Whitney to match the overseas achievements. He brought in a colleague from MIT, William Coolidge, and invited him to work on tungsten. The metal was brittle, easily crumbling to powder, but Coolidge rendered it tractable enough to shape into filaments that were useful, though still fragile.

This was the situation in 1909, when Irving Langmuir came to G.E. He had learned of Whitney’s lab a few months earlier while attending a technical conference in Schenectady, and he had impressed Whitney by giving a paper at the lab in March. Langmuir asked for a summer job and got it. This was Whitney’s way of trying out prospective employees before deciding whether to invite them to stay on permanently.

While at Stevens, Langmuir had moonlighted as a consultant for a variety of companies and government agencies, giving him a wide range of research experience. So when he came to G.E., Whitney did not assign him a project but rather told him to talk to the staff scientists and see if any of their efforts looked interesting. That, too, was Whitney’s way, for as one of the lab’s founders later wrote, “We all agreed it was to be a real scientific laboratory.” Whitney knew that to attract the best people, he had to encourage them to make G.E.’s problems their own.

He insisted that everyone keep detailed lab notebooks, which could prove essential in patent disputes, but in other respects he followed practices of the academic world. He ran a colloquium series with invited speakers, who told of recent discoveries in such areas as radioactivity and the behavior of electrons, and he encouraged his staff members to build their reputations by publishing in professional journals.

Within this relaxed environment Langmuir quickly decided to study tungsten filaments. He suggested that impurities in the metal might be causing brittleness, and he set out to trap those impurities in what was becoming his characteristic style: by capturing them as they vaporized from a heated tungsten wire.

He soon found out that the filament not only was producing gas but was yielding preposterous amounts. He later wrote that the volume of the gas was “7000 times that of the filament.” Clearly these gases could not have come from impurities in the tungsten alone, and by summer’s end he had found the source. The walls of the glass bulb contained water vapor that slowly diffused into the internal vacuum, its molecules breaking apart when they hit the hot filament. The gases he was observing were the disintegration products from that water vapor.

THIS WORK SHED LITTLE light on the problem of brittle filaments, but Langmuir’s resourcefulness convinced Whitney that he was a valuable man who deserved a full-time job. Langmuir took it with a will and never looked back. Once again he was free to pursue the research of his days in G’f6ttingen, with hotter filaments and better vacuums than he had ever before encountered. “I confess I didn’t see what applications could be made of it,” he wrote, “nor did I even have any applications in mind.” But Whitney remained supportive, telling Langmuir to “feel perfectly free to go ahead on any such lines that seemed of interest.” Langmuir responded by injecting a number of different gases into his electric test tubes and studying their high-temperature behavior in detail.

Meanwhile Coolidge was finding ways to make his tungsten ductile rather than brittle. This addressed the immediate challenge, allowing G.E. to market high-efficiency tungstenfilament bulbs during 1911. But a new problem arose: The bulbs turned black. A dark deposit slowly built up on their interiors, dimming them severely after a few hundred hours of service.

Other scientists believed that this blackening resulted from trace gases inside the evacuated bulb. Langmuir conducted experiments and found that, in fact, the tungsten was slowly evaporating within the vacuum, its vapor condensing on the glass. Trace gases did not influence this evaporation, which meant that better vacuums would not help. Instead, Langmuir proposed to go in the opposite direction, by filling the bulb with an unreactive gas, such as nitrogen or argon. His experiments showed that “the rate of evaporation was greatly decreased by the gas, many of the evaporating tungsten atoms being brought back to the filament after striking the gas molecules.”

Yet while a gas-filled bulb might offer a long useful life, the gas would also conduct heat away from the filament, cooling it and spoiling the high efficiency that had made tungsten attractive in the first place. Langmuir showed how to deal with this problem as well. His experiments had given him considerable understanding of the detailed processes by which heat would flow from a hot filament into a surrounding gas. He proceeded to design a new filament in the form of a coiled helix, which would produce plenty of light while minimizing the heat loss. With this filament, sealed inside a globe of nitrogen (and later argon), he arrived at the electric light bulb in the form we use today. Protected by patents, it regained for G.E. the unassailable position that the firm had previously held with its Edisontype bulbs.

Here was the fulfillment of Whitney’s hope. Basic research, complementing invention and product development, had created new devices and given G.E. an important advantage in its ongoing battles with competitors. The work suited Langmuir. He said later that at G.E. “there was more academic freedom than I had ever encountered in any university.”

His personal life flourished along with his career in Schenectady. In 1912, at age thirty-one, he married a woman named Marion Mersereau, whom he had met at a church social. Marion shared his interests: mountain climbing, sailing, and classical music. They adopted two children, and his wife was pleased by “his … great love for them, endless patience in talking to them. He was as great a husband and father as he was a scientist.”

Within the realm of science he found new frontiers to explore when he began studying the vacuum tubes used in radio. A few years earlier the physicist Lee de Forest had invented the basic tube, which had much in common with the light bulb. Like a light bulb, it relied on a heated filament within an evacuated glass envelope, though this filament was meant to provide a flow of electrons rather than light. Ernst Alexanderson, a colleague of Langmuir at G.E., had been working actively in wireless telegraphy and now sought to invent a radiotelephone. He wanted to use de Forest’s tubes in his transmitter and was disappointed because they couldn’t function at high power levels. The tubes worked well in receivers, amplifying a weak signal picked up by an antenna, but they lacked the power to serve in transmitters.

NO ONE REALLY UN derstood how vacuum tubes worked. A British physicist, Owen Richardson, had come up with a theory for the emission of electrons from a hot filament in vacuum. But the chemist Frederick Soddy, a pioneer in the study of radioactivity, thought Richardson had solved the wrong problem. Soddy believed the vacuum tube actually relied on chemical effects in traces of gas within an imperfect vacuum. At G.E., Whitney believed that Soddy was right. So did Langmuir, who conducted experiments and discussed the matter with Richardson personally in October 1912. “He cannot adequately defend his theory,” Langmuir wrote.

But in reviewing his experimental findings, Langmuir decided that Richardson was partly right after all. His theory was merely incomplete, for it left out an effect that Langmuir discovered and called “space charge.” When a powerful current sent electrons flying from a filament, they filled the nearby space. Their electric charges then repelled other electrons and kept them from leaving the filament. So when Alexanderson put high power into his tubes, it was like trying to send more traffic onto a crowded highway. Instead of getting the intense flow of electrons he wanted, he only made the traffic jam worse.

Langmuir combined his space-charge theory with Richardson’s earlier work and devised ways to build suitable high-power radio tubes by increasing the voltage and inserting a positively charged grid to counteract the space charge. His work also gave him an understanding of the way conventional tubes worked, making it possible to improve their design as well. Over the next few years these developments led G.E. into two new and major areas: radio and X-ray equipment.

Within Whitney’s lab, colleagues of Langmuir invented powerful tubes to serve as amplifiers and other circuit elements. In 1914, as World War I started in Europe, they were confident that radiotelephones could span the Atlantic. The war gave this work a strong boost as the U.S. Navy ordered radio equipment for use on its ships. After the war G.E. pooled its radio patents with those of its main competitors, Westinghouse and AT&T, to form the Radio Corporation of America (RCA). Commercial broadcasting followed quickly.

X-ray equipment attracted the interest of William Coolidge, Langmuir’s colleague who had developed ductile tungsten for light-bulb filaments. X-ray tubes, like vacuum tubes, used a heated filament to produce a stream of electrons. These electrons produced X rays when they struck a target made of a heavy metal such as platinum. Like de Forest’s early radio tubes, the first X-ray tubes could only produce low-intensity beams, because their electron sources were weak. The glass bulbs of X-ray tubes also contained traces of gas, which made their output fluctuate unpredictably.

Langmuir’s vacuum-tube discoveries proved useful to Coolidge, who applied them to build X-ray tubes that were both powerful and predictable in performance. In 1913 Coolidge showed such a tube to leading radiologists. They responded enthusiastically, declaring that it not only would be valuable in diagnosis but might even find use in treating cancer. G.E. went on to enter the field of medical X-ray equipment and rose to world leadership.

The new tubes, both radio and X ray, demanded the highest achievable vacuums. Langmuir helped in this area as well, for in 1916 he described his invention of an improved vacuum pump. Most vacuum pumps of the day employed simple suction. Langmuir’s used a stream of mercury vapor as a sort of artificial wind to sweep traces of gas from a chamber, with the mercury then condensing on a plate chilled with cold water. It could create vacuums a hundred times as great as those made with previous pumps, and it worked rapidly. In two seconds it could reduce a rough vacuum to one ten-thousandth of its original pressure.

Yet another element of vacuum tubes drew Langmuir’s attention: the electron-emitting filament. In producing ductile tungsten filaments for light bulbs, Coolidge had mixed that metal with thorium oxide, a temperature-resistant ceramic. This yielded thoriated tungsten, a type of alloy. It was natural to check whether this new material was a good electron emitter as well, so Langmuir carried out tests, beginning in 1913. Thoriated tungsten filaments yielded up to fifty times as many electrons as pure tungsten, and they were soon incorporated into the company’s line of vacuum tubes.

With his research flourishing and branching like a healthy tree, Langmuir’s work with filaments and vacuum tubes led him in two new directions after World War I. In one of them he would pump a tube down to vacuum, introduce a small quantity of gas, and then pass an electron discharge through it. The method was not original with Langmuir—it dated to the nineteenth century—but recent innovations had made it possible to use discharges of particularly high voltage. To take advantage of these expanded possibilities, he invented a new instrument, a type of electrode called the Langmuir probe. When he used it to examine the flows of electricity in his discharge tubes, he found a rich array of new physical effects.

With no current, the rarefied gases within his tubes consisted of discrete atoms or molecules. But when he turned on a high current, the intense flow of electricity caused electrons to break away from their atoms. The gas then became a mixture of freefloating electrons and positively charged ions. It was a new state of matter, neither solid nor liquid nor gas. It needed a name, and Langmuir called it “plasma” for its fancied resemblance to blood plasma.

Plasmas had many novel properties. Not only could they conduct electricity; they could produce internal electric currents that surged back and forth at high frequency. Most surprisingly, the electrons and ions within a nlasma could exist at different temperatures. The electrons were sometimes up to a hundred thousand degrees hotter than the ions, which meant that they must be receiving energy in some fashion to keep them from cooling down. The source of the energy proved hard to determine, and Langmuir saw that his new field of study would indeed be demanding. It became known as plasma physics.

Meanwhile, Langmuir’s work with thoriated tungsten filaments led him in a second direction. Using careful heat treatment, he prepared specialized filaments with a thin film of pure thorium on the surface. He found that they emitted electrons up to a hundred thousand times more effectively than pure tungsten. In 1923, with a brilliant analysis of his experimental data, he determined that this extraordinary performance resulted from a layer of thorium that was only one atom thick.

This fitted in with work Langmuir had published between 1914 and 1917, in the days when he had studied the behavior of traces of gas exposed to hot filaments. Back then he had found that a number of interesting chemical reactions took place within single-atom films on the surface of the heated wire. He had even succeeded in coating the interior of a glass light bulb with a one-atom-thick layer of hydrogen. By studying such films, he determined the size of a hydrogen atom. The surprisingly high electron emission from his thoriated filaments now convinced him that these extraordinarily thin films could be a profitable subject for further investigation.

Throughout his career Langmuir had worked with simple equipment, amounting to a standard light bulb or vacuum tube fitted with instruments. He soon learned that he could create thin films using similarly simple equipment. In fact, a large open pan of water would do. In the mid-1910s, borrowing a technique from Lord Rayleigh and others, he would drop a small quantity of oil onto its surface and watch it spread to form a film one molecule thick. Optical techniques could measure the film’s thickness, allowing him to determine the length and diameter of its molecules. He visualized some oil films as made up of trillions of long, waving molecules, like grass in a swamp. Stearic acid (C 17 H 35 COOH), a pure form of tallow, had molecules with lengths of two-billionths of a meter and widths of one-fifth as much. Olive-oil molecules were more nearly spherical, while the molecule of castor oil resembled a disk.

Langmuir also opened a new topic in biochemistry by studying thin films formed from protein molecules. Such films are permeable, allowing carbon dioxide and other substances to pass through. Langmuir found that by adding salts to the water on which the films floated, he could produce large changes in their permeability. In 1936 he wrote that such films had properties “similar to those of a cell wall. In these experiments we have the advantage, however, that we can make this artificial cell wall cover a square foot if desired; we can study in detail properties which would be very difficult to measure on a living cell.”

As Langmuir broadened his research, he kept active at hiking, skiing, and mountain climbing. He could hike fifty miles in a day, and he ascended the Matterhorn when he was forty with no physical conditioning. He formed a friendship with Charles Lindbergh around 1930 and proceeded to take flying lessons. On his first solo flight, according to legend, his plane went into a tailspin. His instructor watched from the ground for a long half-minute, holding his breath, until the plane finally righted itself and made a good landing. Langmuir explained that he had gone into the spin on purpose, just to see what would happen. As another example of Langmuir’s wide-ranging interests, he had spent much of World War I researching binaural sound with a view to aiding submarine detection. Years later he would combine these findings with his love of music in working with the conductor Leopold Stokowski to create better sound recordings.

In science, just as in flight training and music, Langmuir went beyond the ordinary. One can appreciate the breadth of his activity by contrasting it with Thomas Edison’s. Like Langmuir, Edison had found that his light bulbs blackened in use. Searching for a way to prevent this, he placed a piece of metal inside the bulb, close to the filament, with a wire running through the glass. To his amazement, he found that an electric current flowed from the filament to the metal, even though there was no connection between the two.

Edison observed this effect in 1883 and patented the apparatus, but he couldn’t find any use for it. Then in 1904 the inventor John Ambrose Fleming used the “Edison effect” as a basis for the first vacuum tube, which could detect radio waves received by an antenna. Two years later de Forest turned this “Fleming valve” into a true radio tube, capable of amplifying. This tube became the starting point for Eangmuir’s contributions and for the subsequent development of radio and other electronics.

Edison was still active during the 1920s, as radio swept the nation, and he realized that he had missed it. His failure to develop the patent had left others to turn his Edison effect into working circuitry. He became so chagrined he put a sign on his office door reading I WILL NOT TALK RADIO TO ANYONE .

While Langmuir went much farther than Edison, he, too, could fall short. This happened just after World War I, when he became interested in the structure of atoms. Expanding on the earlier work of G. N. Lewis, Eangmuir proposed the now-familiar view of the atom as a central nucleus surrounded by shells of electrons. The shells would be completely full when they held certain numbers of electrons: 2, 8, 18, 32. Those short of completion would-seek to fill their shells by combining with other elements that had surplus electrons.

LANGMUIR’S THEORY proved an enormous success. The periodic table of the elements had been familiar to chemists since the 1870s, when Dmitri Mendeleev first noticed that if the elements were arranged in order of increasing weight, certain chemical properties recurred at regular intervals. Until Langmuir, though, no one had come up with a satisfactory theoretical explanation. His theory clarified a host of observations concerning the elements’ chemical behavior. It entered courses on elementary chemistry, being taught even in high schools, and became part of the working knowledge of professionals in this field.

Yet even as Langmuir carried through the development of his theory, around 1920, the focus of atomic research was shifting from chemistry to physics—specifically, the arcane, highly mathematical field of quantum mechanics. Langmuir might have contributed to the development of quantum physics, but he didn’t. He left the matter to specialists in Europe: Werner Heisenberg, Erwin Schrödinger, Max Born, Niels Bohr. Twenty years later quantum mechanics became a key to the future of electronics, a field in which Eangmuir had pioneered.

Langmuir spent much of the 1920s experimenting with atomic hydrogen. His work yielded a wealth of fundamental data on this simplest of atoms as well as a practical application—the atomic-hydrogen torch, which could reach temperatures of 6,800°F and weld metals that would not melt in the flames of conventional torches. In 1932 he was awarded the Nobel Prize; the citation emphasized his work with single-molecule films. That same year he was appointed associate director of G.E.’s Research Laboratory, a post he would hold until 1950, when he retired.

During the 1930s Langmuir continued his research in fields old and new. In 1935 he even made a brief venture into politics, running unsuccessfully for Schenectady’s city council. He was increasingly drawn to what he called “out-of-doors science,” such as meteorology and the effect of wind on ocean waves. Other 1930s publications included “Air traffic regulations as applied to private aviation” and “The speed of the deer fly.” His research during World War II included work on smoke screens, and in the course of it, he noticed that the chemicals used to create the screens sometimes cleared up local accumulations of fog. This observation led him to investigate ways of producing rain, particularly cloud seeding. He became a pioneer in this new field and scored some successes, but the work faded amid the threat of legal liability. Nor did it help when a hurricane that was headed out to sea turned around and hit the coast after being seeded. Following his retirement from G.E. he remained active as a consultant until his death in August 1957.

Langmuir remained a man of his era, in a time when American research still could not measure up to the best of Europe’s. Not until World War II, well after he had done his best work, would American science truly establish its strength. Yet even today he shines as a consummate experimentalist, a man who could see new worlds within a common light bulb. Moreover, he did all his important work within G.E.’s industrial research lab. By ranging far beyond the narrowly practical concerns of Edison, he demonstrated that imaginative industrial research could stand alongside the best work universities had to offer.