Illustration: Rob Magiera
The son of a British Quaker schoolteacher who became a brilliant orator but believed that practical study was more important than lectures, a mathematical genius fleeing Germany because of his socialist views who was almost turned back by New York customs officials as medically unfit, and two educators, one self-taught in engineering, the other an inventor of analog computers—what did they have in common? Their textbooks on electrical technology were among the few classics that helped establish a new discipline and set the world onto a path that would eventually lead to pocket computers, broadband Internet access, and plasma-screen TVs.
Electrical engineering emerged as a profession in the 1870s and 1880s, when, for the first time, inventors devised such wonders as effective generators, practical arc lamps and incandescent bulbs, effective motors, transmission of power from central stations, and the telephone. Indeed, there had been earlier electrical technologies—the lightning rod, electroplating, and, most importantly, the electric telegraph—but these were not sufficient fodder to nurture a full-fledged profession.
As the list of inventions grew, developing and exploiting the new technologies behind them required a high level of mathematical and scientific training. Universities around the world stepped in to offer courses in electrical technology, both by setting up engineering programs and by adding courses in physics departments.
Colleges in Switzerland and Japan led the way. The first courses were taught in the 1870s at the Eidgenössische Technische Hochschule (ETH, the Swiss Federal Institute of Technology) in Zurich and at the Imperial College of Engineering in Tokyo. During the next decade, two German schools, the Technische Hochschule Darmstadt and the Technische Hochschule Berlin-Charlottenburg, established EE professorships in 1882 and 1883, respectively. Three British schools competed for students in the mid-1880s: City & Guilds of London Institute for the Advancement of Technical Education (which set up Finsbury Technical College), Central Technical College, and University College, all in London. In the United States, the Massachusetts Institute of Technology (MIT), Cornell, Columbia, the Case School of Applied Science (later Case Western Reserve University), and the University of Missouri were among the schools that established EE programs in the 1880s.
Scholars soon began writing textbooks to help teach students the new discipline. Scattered among the many fine texts that have been written over the past 140 years are the truly great ones—those that have endured for many generations of students, challenged them to solve practical problems, and inspired them to extend the field.
In this article, 13 of these texts are described. Nine more will be covered in a future issue of IEEE Spectrum. While only a small subjective sample of the great EE textbooks, these 22 texts were chosen because they illustrate the century-long development of electrical engineering from the 1880s to the 1980s, as well as the transnational character of the technology.
Dynamos, motors, and power lines
One of the most remarkable of the first English-language textbooks in electrical engineering offered both theoretical and practical information. In Dynamo-Electric Machinery: A Manual for Students of Electrotechnics (1884), Silvanus Phillips Thompson, a teacher at University College, Bristol, discussed the general physical theory that was the heart of all types of dynamo-electric machines and then showed how to design them.
The book was in such great demand in industry as well as in schools that it went through several editions very quickly in both Britain and the United States. By the time the eighth U.S. edition appeared in 1901, it was translated into several languages. Nobel Prize winner Ernest Rutherford wrote, “I cut my first teeth on Dynamo-Electric Machinery,” which he praised for the “clearness, simplicity, and charm [that were] characteristic of all [Thompson’s] writings and lectures.”
At Finsbury, Thompson gave 10-12 lectures a week, but always told his students that time spent in the laboratory was more important than time spent attending lectures. Besides his college work, he was in great demand as a speaker, not only in England but on the continent as well because of his fluency in Italian, German, and French.
The author of several other influential EE textbooks, Thompson is surely one of the greatest explainers of all time. To help his students grasp differential and integral calculus—essential for the electrical engineer—he invented a new way of presenting the subject, and his Calculus Made Easy (1910) became the most successful calculus primer ever. It has sold more than a million copies and is currently in print in two versions, one of them a 1998 revision by Martin Gardner, who said of Thompson that “no author has written about calculus with greater clarity and humor.”
Thompson, the son of a British Quaker schoolteacher, took a strong interest in the history of his profession as well. His Dynamo-Electric Machinery, for example, included historical notes that, unfortunately, were forced out of later editions as the amount of technical information increased. He also wrote highly regarded biographies of Michael Faraday, the telephone inventor Philipp Reis, and Lord Kelvin. All three of them are still in print!
Another engineer who made key contributions to the profession was Charles Proteus Steinmetz, a German immigrant to the United States. He published textbooks on electrical machines and electric-power transmission and, even more importantly, on the scientific understanding behind these technologies.
Steinmetz did doctoral work at the University of Breslau, but in 1889 he had to flee Germany because of his socialist views. Arriving in New York harbor penniless, and with a swollen face from a temporary illness, Steinmetz, who was only 130 cm tall, was almost turned away by customs officials till a friend vouched for his genius and lied about his wealth. After a few years, he became a research engineer for General Electric Co. in Schenectady, N.Y. Although he was a socialist, he saw no contradiction in working for a profit-driven company because he believed that the growth of corporations would lead eventually to a socialist society.
In the years around 1890, Steinmetz made a thorough theoretical and experimental study of hysteresis, a phenomenon in which a material’s magnetization in a given magnetic field can have two values. It is lower when the field is reached by increasing it from a smaller value, and higher when the magnetic field is decreased from a higher value. The new understanding allowed engineers, for the first time, to calculate the losses due to magnetism in transformers and other ac apparatus.
One of his innovations was the use of complex numbers for analyzing circuits. In 1897 he published the advanced textbook Theory and Calculation of Alternating Current Phenomena. Widely adopted, it went through five editions and was translated into several languages. Largely as a result of this book and other writings by Steinmetz, complex numbers became a part of the EE curriculum everywhere.
Another towering figure in engineering education was Dugald C. Jackson, who headed EE departments at the University of Wisconsin (1891-1907) and then at MIT (1907-1935). His constant objective was to match curricula with the needs of industry, and he established ties to industry through consulting contracts and through a cooperative program in which students combined studies and work.
In 1919 Jackson added William H. Timbie and Vannevar Bush to his faculty at MIT—Timbie to head the cooperative program and Bush to teach the introductory EE course. These two new professors collaborated on a textbook for that course: Principles of Electrical Engineering (1922). A demanding book, it assumed a knowledge of calculus and physics and included some 500 problems “for illustration, for practice in applying the principles and for the purpose of bringing before the student useful and interesting engineering data.” That same year the publisher, John Wiley & Sons, provided a booklet of answers to these problems. The book became widely used, appearing in four editions in the United States (the last in 1951) and in translation in other countries.
In one of 500 problems presented by the authors, studentsare asked to calculate the electric potential between the conducting wires (A and B) and a ground wire just after a lightning discharge, from Principles of Electrical Engineering by William H. Timbie and Vannevar Bush.
Bush went on to even greater things. He invented the differential analyzer and other analog computers, and was the architect of the military-industrial complex that directed government-sponsored research during World War II. After the war, he helped establish the U.S. National Science Foundation. He was also years ahead of his time in proposing, in 1945, the Memex, a device for retrieving and cross-referencing information, and a conceptual precursor of today’s hypertext.
Timbie continued to excel as an educator. For 28 years he administered the MIT cooperative program, which served as a model for many other universities, and he authored another six highly successful textbooks on electricity and electrical engineering, two of them with Henry Harold Higbie. Timbie is unique among all the authors mentioned in this article in that, educated as a classicist, he was self-taught in mathematics, physics, and engineering.
He also had the advantage of working with talented colleagues. He said on one occasion: “If Bush could get the ideas through my thick head, I could put across the concepts so that the students could understand them.” In his classes, he would try out different explanations to see which one the students could best grasp, and his books certainly benefited from this empirical approach to teaching.
Vacuum tubes: the first textbooks of electronics
Contents
Around the turn of the century, the first examples of a new type of electrical technology, the X-ray tube, appeared. Invented by Wilhelm Röntgen in Germany in 1896, it was soon put to use for medical imaging. The following year, another German engineer-scientist, Ferdinand Braun, invented the cathode-ray oscilloscope to study rapidly varying electric currents.
With turn-of-the-century experiments in wireless communications came a need for an effective means of detecting electromagnetic waves. Seeking to deliver that capability, English physicist John Ambrose Fleming in 1904 invented a two-electrode vacuum tube, later called a diode, and in the United States, in 1906, Lee de Forest invented a three-electrode tube, later called a triode. Their inventions opened up a whole new field of electrical engineering, and fueled its second great period of growth.
In traditional electrical engineering, electrons flow entirely in conductors. But these new devices forced electrons to move through a vacuum. The devices proliferated during World War I and afterward, especially for radio, which used the electron tubes as amplifiers, oscillators, modulators, and detectors. With the explosive growth of broadcasting in the 1920s, radio engineering became an important profession, and the need grew for textbooks in the new technology of electronics. The field would later be defined as the engineering of devices involving controlled electron flow through vacuum, gas, or semiconductors. Fleming, one of the originators of electronics, provided a highly influential book on the topic.
A professor of electrical technology at University College in London, Fleming also worked for several years as scientific advisor to the Marconi Wireless Telegraph Co., an arrangement that ended in December 1903 when the company did not renew his contract. Wanting badly to regain that position, Fleming felt it was crucial to invent something of unquestioned value to wireless telegraphy. In late 1904, he devised what is now called the Fleming diode, the first radio tube, and in May 1905, Marconi reappointed him as its scientific advisor.
An assiduous experimenter and an insightful theoretician, Fleming presented the state of the art in his 690-page The Principles of Electric Wave Telegraphy (1906). The book presents Maxwell’s theory and applies it skillfully in explaining Heinrich Hertz’s experiments and later work on electromagnetic waves [see figure]. The book went through three more editions, being updated in 1910, 1916, and 1919, and the title was lengthened by the addition of the words “and Telephony.” Fleming made countless contributions to radio, especially measurement techniques, and he remained scientifically active nearly until his death in 1945 at the age of 95.
In the years between World Wars I and II, electron tubes found more and more applications: among them were the telephone repeater, control devices, scientific instruments, the electronic phonograph, public-address systems, sound movies, FM radio, television, sonar, radar, and carrier telephony, which sends multiple telephone signals over the same line. This blossoming of electronics depended on understanding tube behavior and the improvement of tube design, and a person who contributed as much as anyone to this effort was Heinrich Barkhausen.
A professor at the Technische Hochschule Dresden, Barkhausen specialized in telecommunications. During and after World War I, he studied electron tubes, introducing tube coefficients—that is, ways to describe tube behavior—that became standard worldwide. His scientific investigations led to improved tube design. The Barkhausen-Kurz oscillator, for example, generated ultrahigh frequencies that, by the 1930s, were not far from the microwave range.
Other areas interested Barkhausen as well. In acoustics, for example, he proposed the logarithmic scale of loudness as measured today in decibels. In magnetics, he produced the first direct evidence of ferromagnetic domains, discovering what is now called the Barkhausen effect—that a steady increase in an applied magnetic field causes a stepwise change in magnetization. In 1923 the first volume of his Elektronen-Röhren appeared. It would eventually become a four-volume work that described many of his discoveries and advances. It was translated into other languages, including Japanese and Russian, and used in universities for half a century. The 12th edition appeared in 1969.
The rise of electronics
As electronics and communications became more important in the 1920s and 1930s, EE departments began offering individual courses in the emerging techniques. With this new emphasis, the traditional basic EE course, directed toward power engineering and electrical machines, no longer proved the best foundation for the entire field.
Providing a model of a new introductory course, Einführung in die theoretische Elektrotechnik ( Introduction to Theoretical Electrotechnology), by Karl Küpfmüller, appeared in Germany in 1932. It not only presented the physical principles of electric current, electric and magnetic fields, and networks that underlie all types of electrical and electronic engineering, but it encompassed, in a single theoretical framework, both power engineering and the newer discipline of electronics.
For several generations of German EE students, Küpfmüller’s was the basic textbook, and new editions have appeared fairly regularly over the years. The 15th edition came out just two years ago. The author, prolific in both patents and publications, alternated between industrial research at the central laboratories of Siemens & Halske from 1921 to 1928 and from 1937 to 1945, and academic teaching and research at the technical universities in Danzig, Berlin, and Darmstadt.
A pioneer in the analysis of electric filters, Küpfmüller in 1924 pointed out an inverse relationship between frequency and time domains: the narrower the bandwidth, the greater the rise/settling time of the signal. His 1949 book, Die Systemtheorie der elektrischen Nachrichtenübertragung (System Theory of Telecommunications), was a landmark contribution to the emerging discipline of communications theory. He is also regarded as a founder of control-systems theory.
Back in the United States, Frederick Emmons Terman, often called the father of Silicon Valley, began, in the late 1920s, to improve the engineering program at Stanford University in California. In 1932, he published Radio Engineering, an advanced text that taught how to calculate the performance of radio circuits “with the same certainty and accuracy that the performance of other types of electrical equipment, such as transformers, motors, and transmission lines, is analyzed.”
Distinguishing this book from others was Terman’s constant concern for the user’s needs: he included mathematical analysis in the book only when it was useful for the practicing engineer, and he kept in touch with industry so that the design information he presented agreed with current practice. There was also a good deal of original material from Terman’s own research. The result was a textbook that was adopted by universities in many countries, in the English version and in several translations, and went through four editions, the last in 1955. Two other highly influential books by Terman were Measurements in Radio Engineering (1935) and Radio Engineers’ Handbook (1943).
One of the new faculty members Terman brought to Stanford was Karl Spangenberg, who was assigned to teach a course in electron-tube design. Dissatisfied with available books, Spangenberg wanted a comprehensive textbook that would present the physical laws underlying electron behavior and relate them to the external behavior of tubes. For five years or so, he labored diligently at the task of writing one, starting his day at five in the morning in order to work two hours on it before going to the university. (This information I have from his wife, Ruth Spangenberg, a psychologist and still-active environmentalist, who in those years had the demanding job of typing her husband’s manuscript.) Finally, in 1948, Vacuum Tubes appeared, the same year that Bell Labs announced the invention of the transistor.
Once the transistor was launched, Spangenberg soon had the job of rewriting his book in order to include the new device. Sporting a new name and the addition of a good deal of solid-state physics, Fundamentals of Electron Devices appeared in 1957. Not surprisingly, it emphasized the similarities between tubes and transistors, proving extremely valuable to all the electronics engineers who lived through that technological transition [see figure].
The semiconductor revolution
Unknown to mid-20th century electrical engineers was the torrent of invention and development that was soon to be unleashed as a result of the transistor’s invention. Integrated circuits with thousands and then millions of transistors were possible. And the computer industry was to flourish as advances in the manufacture of ICs made possible ever more powerful computers.
A second article to be published in July will examine circuit-design and computer textbooks, along with several books that enhance engineers’ understanding of physics and mathematics.
To Probe Further
A good introduction to EE history is Engineers & Electrons: A Century of Electrical Progress by John Ryder and Donald Fink (IEEE Press, 1984).
Excellent biographies of electrical engineers include Paul Israel’s Edison: A Life of Invention (John Wiley & Sons, 1998), Paul Nahin’s Oliver Heaviside: Sage in Solitude (IEEE Press, 1988), and Ronald Kline’s Steinmetz: Engineer and Socialist (Johns Hopkins University Press, 1992). Michael Pupin’s Pulitzer Prize-winning autobiography might also be mentioned: From Immigrant to Inventor (Charles Scribner’s Sons, 1922).
A number of universities have published histories of their EE programs. An example is A Century of Electrical Engineering and Computer Science at MIT, 1882-1982 by Karl Wildes and Nilo Lindgren (MIT Press, 1985).
