Let us revisit our generalizations, and see whether they can help us compare the cognitive processes of Bell and Gray and extract meaningful lessons, substituting the term inventor for discoverer.
1. Invention depends on establishing that a problem is significant enough to be labeled an important achievement.
One way for inventors to find significant problems is to focus on reverse salients. Kilby and Noyce, inventors of the microchip, did this with great success (Reid, 1984). Elisha Gray, however, found that Bell's invention transformed the entire communications industry in a way that made the old reverse salient a minor problem. Bell sought to solve a problem whose significance only he really appreciated.
2. Invention depends on transforming that problem into a form that suggests a promising path to solution which includes locating and transforming the necessary mechanical representations.
Here we have substituted the new term mechanical representation for data. Part of the mind of the inventor is embodied in the special components she crafts. This is often true of discoverers as well.
Gray certainly transformed the technologies available for multiple telegraphy, creating a whole new set of mechanical representations, and patenting combinations among them. Bell, in contrast, sought to come up with a single, best mechanical representation that would embody his mental model of how speech, or telegraph signals, or music might be transmitted and received.
To put it in other terms, Gray's knowledge was more in his devices and Bell's in his sketches and notebooks. Gray was comfortable building a proliferation of sophisticated devices; Bell preferred thought experiments and theoretical reflections, imagining how systems might work.
When I give talks about Gray and Bell, I am often challenged by historians, who claim this combinatory or matrix style of Gray's is simply the result of the spotty records he left--if he had kept the same sort of detailed records as Bell, his cognitive style would look more similar.
First of all, I think it is significant that he did not keep records as detailed as Bell's. Record-keeping is a reflection of cognitive style. Bell used his notebooks as a thinking tool, as well as a means of creating a powerful heroic narrative of his invention. That reflects his goals and style. As early as 1873, he adopted the theme, or role, of a theoretical inventor.
Gray, in contrast, embodied his thinking in devices. That's why he thought his caveat contained the fundamental principles for transmitting speech--even though he nowhere discussed the undulating current, or any of the other theoretical matters raised by Bell in his patent. For Gray, the principles were embodied in the device, which told the whole story.
While Bell tried to find a single, simple device that would represent his goal, Gray created multiple devices which were better suited to different telegraph applications and which would allow him to patent different approaches to the problem of telegraphy. When asked to recall his invention process, he listed devices and experiments conducted with them. Gray left almost no other records because he didn't need them--his devices were his memory, and practically spoke for themselves.
One could try to adapt the language of the dual-space approach to scientific reasoning. Recall that Klahr and Dunbar found two cognitive styles among participants in one of their Big Trak experiments: theorists, who spent more time searching a hypothesis space, and experimenters, who spent more time in an experiment space (Klahr, 1988). Bell's style resembles that of the theorists; he spent a good deal of time considering alternate hypothesis for designs, conducting thought experiments and even reflecting on his overall mental model in his notebook.
Gray bears more resemblance to the experimenters, in his preference for creating devices rather than thinking about what sort of current would best transmit speech or musical tones. But the term experimentalist isn't quite right for Gray. He would be better described as working in a space of mechanical representations, developing multiple variations. Bell, in contrast, sought to develop the simplest possible mechanical representation that would embody his mental model for the transmission of speech.
Klahr and Dunbar's participants were trying to come up with an appropriate mental model for operating a device, not building one. The theorist/experimenter distinction does not incorporate invention, but Gary Bradshaw used a dual-space approach to explain why the Wright Brothers were so far ahead of their competitors. Instead of hypothesis and experiment spaces, he argued that inventors like the Wrights worked in design and function spaces (Bradshaw, 1992). The problem with Wright competitors like Langley and Chanute is that they worked almost exclusively in a design space, varying parameters like the location and number of the wings without carefully considering their function. Typically, these inventors would construct aircraft to test their new design ideas and fly them.
In contrast, the Wright brothers' goal was "to achieve certain functions in an airplane; lateral control, sufficient lift, a reduction in drag, etc." (Bradshaw, 1992, p. 248). In other words, they decomposed the problem into functional slots. The brothers built only three gliders before constructing their successful airplane. After careful analyses of their first two gliders, they built a wind tunnel and tested more than one hundred wing shapes before producing the first flying machine.
They also formed unique mental models and sets of mechanical representations. As Tom Crouch noted, "Wilbur and Orville had a genius for visualizing the abstract--a gift for thinking in terms of concrete graphic images. That was what set them apart." (Crouch, 1992, pp. 84-5). They were experienced bicycle mechanics, and that background helped them understand that an airplane, like a bicycle, would have to roll, and that the pilot would need to be able to control that roll. Other inventors assumed an aircraft would have to be stable after it was launched. The Wrights used birds as a mental model for how to control this roll: birds adjusted the tips of their wings, presenting one tip at a positive angle and another at a negative one. Wilbur simulated this by twisting a piece of cardboard; he saw that a pilot might be able to warp the wings in the same way. "The Wrights had taken a set of graphic images--a bicycle speeding around a corner, a bird soaring through the air, a cardboard box twisted in the hands--turned them into thought problems, and reassembled the lessons learned into a mechanical system for controlling a plane on a roll axis." (Crouch, 1992, p. 86). To put it in terms of our framework, the Wright brothers created a slot for wing warping.
In the course of their experiments with the coefficients of lift, the Wright brothers created a variety of mechanical representations, including a set of balances for measuring lift and drag. This meant they could calculate the coefficient of lift without using the standard equations. "They had grasped the possibility of devising a mechanical expression of a complex mathematical equation. They had visualized a way in which the incredibly complex play of forces operating on that machine would be directed so as to produce the precise bit of information required. Seen in this light, the lift balance, and the drag balance, must be recognized as intellectual achievements of staggering proportion." (Crouch, 1992, p. 91)
Like the Wrights, Bell had a functional goal: to find the simplest possible means of translating the undulating curves he had seen on the phonautograph into an undulating current. Gray, in contrast, generated a proliferation of alternate designs with little apparent analysis of their functions. So we might say that Bell spent more time in a function space, and Gray in a design space.
But like Gray, the Wrights also developed a sophisticated set of mechanical representations, including balances for measuring lift and drag. It is not sufficient to say that one should conduct a coordinated search of design and function spaces; one must have a mental model to guide one search and be able to invent or borrow mechanical representations that create the necessary data. Much of an inventor's cognition is embodied in devices. For Bell, a number of these devices, like the harp apparatus, existed only on paper and served as mental models. In contrast, Gray' seems to have preferred a kind of experimental benchtop space, in which he could analyze and imagine by building. Part of an inventor's mind is in the devices he or she creates.
3. Invention depends on a combination of flexibility and stubbornness, depending on the cognitive styles and career trajectories of the inventors involved and on how they represent the problem.
Gray stuck stubbornly to a mental model based on the idea that musical tones could be used to carry telegraph messages. But Gray showed great flexibility in generating alternative ways of converting this mental model into practical devices, and devices like the mechanical transmitter led him in turn to alter his mental model, in this case to incorporate the possibility of speech. For Gray, speaking telegraphy remained a relatively minor extension of harmonic telegraphy.
Like Gray, Bell began with the idea that multiple telegraphy was the problem to solve. But his unique background led him gradually to elevate speaking telegraphy to the primary goal, although he continued multiple telegraph experiments after the Centennial and emphasized telegraph applications in his patents. Once Bell developed an overall mental model for the transmission of speech, based on the human ear, he stuck stubbornly to it, returning to it after a long series of successful experiments with a liquid transmitter. But these experiments also showed his flexibility--he gradually abandoned the idea that the form of the armature would resemble the ossicles, and kept the function: translating sound into an undulating current. To put it in Lakatos' terms, both inventors had hard core ideas they were unwilling to abandon, but outside of these hard cores they showed flexibility.
In terms of Bruner's conservative focusing and focused gambling heuristics, both Bell and Gray could be said to prefer the former to the latter. Recall that conservative focusing involves changing one thing at a time as one experiments, while focused gambling involves making multiple changes at once. Bell's notebooks show his preference for changing one or at most two aspects of a system when conducting a new test. Gray used conservative focusing in a somewhat different way; he tried each of his transmitters with each of his receivers, then patented the most promising combinations. Gray's caveat for a speaking telegraph looks like more of a focused gamble, but even that looks more conservative on closer inspection. Gray's liquid transmitter was essentially an 'off-the-shelf' component he was familiar with from telegraphy, and the receiver was one of his familiar mechanical representations.
Of course, it could be that the more closely one study's the invention process, the more it looks conservative--each insight, each new combination appears to be a small step from previous work. Even Jack Kilby's bold leap to the microchip might be viewed as a conservative change: he kept all the components of the circuit, he just etched them on silicon. But this move represents a fundamental change in the mental model. To put it in Klahr & Dunbar's terms, what appears to be a conservative shift in the experiment space may be triggered by a radical shift in a space of mental models that in turn leads to a new set of possibilities.
4. The act of writing is part of the invention process.
Clearly, this generalization holds true for Bell. His notebook was instrumental in his discovery the heavy metal armature he patented in January of 1877. He also used his letters and notebooks to construct a powerful invention narrative, which he repeated endlessly in litigation.
Similarly, the midwestern agricultural inventors studied by Colangelo (Colangelo, et al., 1993) all kept notes: "Most wrote on whatever was handy, rather than keeping formal journals, but they 'never misplaced those notes'" (163). What is needed are detailed studies of these notes: what methods the inventors used to keep them, whether and how they played a role in new inventions, whether and how they were used to resolve patent disputes.
Writing apparently played less of a role in Gray's invention process. In patent testimony, he uses assistants like William Goodridge to serve as witnesses for experiments, rather than referring to notebook entries or letters (1880). Gray did write articles for journals like the Telegrapher and provided accounts for newspapers. He was acutely aware of the need to publicize his inventions. To buttress his claim to have invented the speaking telegraph, he wrote an extended account of his experimental researches (Gray, 1977).
We might also add that visualization is an important part of the invention process. Finke did a series of experiments in which he asked participants to combine simple geometric shapes to create what he called preinventive forms (Finke, 1990). For example, one student, given a hemisphere, cylinder and line to work with, put the cylinder on the hemisphere, attached the line to the top of the cylinder as if it were hung from the walls of a room, and called the resulting combination a 'hip exerciser': one could stand on the hemisphere, hold onto the cuylinder, and rotate one's hips (Ward, 1995).
Most participants in Finke's experiments were able to come up with at least one preinventive combination that judges scored highly on originality and practicality. This kind of 'preinventive' visualization can play an imporant role in the creation of new mental models and mechanical represenations. Indeed, Finke's experiments demonstrate that function can often follow form.
Finke's participants did not keep notebooks or provide written justifications of their invention ideas, so it is impossible to know whether writing would have facilitated their invention processes. Finke recommends recording preinventive forms in a notebook. According to Finke, what distinguishes really creative people is not just or even primarily their ability to generate creative images, but their willingness to explore them for extended periods of time.
We might also add that visualization is an important part of the invention process. Finke did a series of experiments in which he asked participants to combine simple geometric shapes to create what he called preinventive forms (Finke, 1990). Most participants were able to come up with at least one preinventive combination that judges scored highly on originality and practicality. Finke's participants did not keep notebooks or provide written justifications of their invention ideas, so it is impossible to know whether writing would have facilitated their invention processes. Finke's studies do demonstrate the creative power of visualization.
Similarly, Edison left extensive records of his invention of the carbon transmitter and used them in court, but they consist almost entirely of sketches. For inventors, words are often less important than sketches, prototypes and even mental modeling. Tesla claimed that he envisioned many of his electrical inventions. "The pieces of apparatus I conceived were to me absolutely real and tangible in every detail, even to the most minute marks and suggestions of wear. I delighted in imagining the motors constantly running..." (Cheyen, 1981, p. 24). Elmer Sperry, a prolific inventor most famous for his marine gyroscopes, "was strongly visually oriented" (Hughes, 1971).
So in the case of inventors we might add sketching and even mental modeling to our generalization about the importance of writing. Even so, in the end, the inventor must either write a patent, or find someone who can write it. Consider the successful inventor Jerome Lemelson, who has over 500 patents to his credit, but rarely builds prototypes of his ideas, let alone market or manufacture them. He made his fortune by developing complex heuristics for keeping patents alive over long periods of time and filing amendments. He licensed his patents to others and, sued those who wouldn't license (Wysocki, 1997). Lemelson wrote all of his own patents: for him, writing and sketching are perhaps the most important part of invention. "Most of my inventions are only in the form of patents, and many of them are quite detailed. I don't see a need for building models of everything I have invented or spending the time and money on models. I know they're helpful in promoting and licensing inventions, but they're not always necessary" (Brown, 1988). Contrast Lemelson with Elisha Gray; the former wrote far more than he built, and the latter built more than he wrote.
Furthermore, like Bell, successful inventors must be able to construct an invention narrative that demonstrates the novelty of their ideas--that contains the 'flash of insight' that patent examiners and jurors look for in determining whether a technological improvement deserves the status of an invention (Seabrook, January 11, 1993). Gray's accounts of his invention process were much sparser than Bell's; and Gray was encouraged to compensate by writing accounts like "Experimental Researches in Electro-Harmonic Telegraphy and Telephony: 1867-1878" (Gray, 1977). It would be interesting to look at the role Lemelson's accounts of his invention process played in his success as an inventor.
5. Successful inventors often pursue a network of enterprises.
Gray's network of enterprises was focused on telegraphy at this time, but encompassed music and autograph telegraphy as well as harmonic telegraphy. In addition to transmitters and receivers, he developed and patented important technologies for improving transmission over long distance lines.
Bell's network was more diverse, encompassing inventions that could be used to visualize speech in addition to telephony, harmonic telegraphy and autograph telegraphy. Bell's network was also interdisciplinary. He alone of telegraph inventors was an expert in elocution and audition, especially in teaching the deaf. This background was his secret weapon. His experiments with the ear phonautograph, for example, played an important role in Bell's mental model for a telephone.
Edison also pursued a network of connected inventions, although he would periodically focus a massive effort on one project, like the development of an electric lighting system, or mining ore in New Jersey. His favorite invention was the phonograph, and mechanical representations from this invention can be seen in some of his telephones and in his kinetoscope. His ore mining experiments were failures, but knowledge and mechanical representations from them played a role in his successful cement manufacturing business; the equipment he used to separate iron from rock was turned to pulverizing limestone (Baldwin, 1995).
Some inventors, however, pursue one invention with a single-minded, obsessive character. Chester Carlson, the inventor of xerography, got his motivation from his experience copying patents by a slow photostat process, and also from the hours copying pages from sources at the library (Dessauer, 1971). He made his kitchen into a laboratory and worked there evenings and weekends, after his job as a patent attorney. Eventually, his wife made him move the laboratory to an apartment owned by her mother-in-law. It was here that Carlson and his assistant Otto Kornei photocopied the inscription "10-22-38 Astoria" on October 22, 1938. The result was crude and smudged and the process hardly suited to manufacturing. But he obtained several patents and for eight years looked for a way to market his idea. Finally, in 1944, he received support from the Batelle Memorial Institute, a privately endowed research and development organization that contracted with companies. It took Carlson and the Batelle two more years to find a company that was interested in working with them. After trying General Electric, IBM, RCA and Kodak, they found a willing partner in the Haloid Corporation. Carlson remained with Haloid for the rest of his life, perfecting this invention. For Carlson, there was no network of inventions; he focused on a single technological breakthrough and championed it throughout his career. But his case reminds us of another kind of networking inventors have to do--they have to build a network of assistants, financial backers and manufacturers if they are going to bring a product to market.
This page was last edited: Wednesday, July 14, 1999