“You do realize that Tom Hughes is the 900-pound gorilla in the history of technology, don’t you?” The question came from one of his colleagues at the University of Pennsylvania’s History and Sociology of Science Department. I’d never heard the idiom before, but its meaning was clear enough. And—incredible as this may seem in retrospect—the answer was no, I didn’t know. When I arrived at Penn in 1986, Networks of Power had been out for three years. The book had immediately gained recognition as a paradigm shift in the history of technology, garnering Hughes his second Dexter Prize along with an impressive collection of rave reviews. He was already deep into his next book, American Genesis. Thanks to a Guggenheim Fellowship and visiting professorships in Stockholm, Berlin, and New York, Hughes had a two-year leave from Penn. But none of that meant much to me starting out as a new graduate student.
Three cohorts awaited Tom Hughes’s return to Penn in the fall of 1988. We hadn’t met him yet, but we were already intimidated. Students called all the other faculty members by their first names, but even the most senior students referred to him as “Professor Hughes.” I felt an extra layer of dread. It was the fall of my third year, and I had committed to researching the history of French nuclear power. When I’d explained this to Svante Lindqvist at a SHOT meeting, he’d had the same response as all the Penn faculty: “Well, of course you are working with Tom Hughes!” But was I? Would we get along? I had serious doubts.
These doubts were not assuaged during the first weeks of the term. The course differed from others on offer. Instead of having us chug our way through a book a week, Professor Hughes plunged us straight into primary sources, assigning a series of paper topics that tracked the progression of chapters in American Genesis. (The book was in the proof stage, so we didn’t even see this parallel until much later.) We grumbled about not [End Page 964] being allowed to choose our source base. Several of us particularly resented the first assignment, which forced us to work with microfilms of the Edison papers. Without much enthusiasm, I researched whether Edison’s invention of the electric pen showed him to be a “systems thinker”; the resulting paper lacked verve. My paper for the second assignment, on Lewis Mumford, had even less sparkle. Professor Hughes commented that Mumford “was a more subtle thinker than you’ve given him credit for.” Things were not off to a good start.
Fortunately, the third paper topic proved more inspiring: we were to write about some aspect of modern architecture. Here, at least, we had some choice. Eager to get into French-language sources, I decided to write about Le Corbusier. I soon lost myself in old issues of Esprit Nouveau. Le Corbusier’s misguided utopian zeal fascinated me, especially his trajectory from postwar social housing to luxury mansions to impossibly huge post-colonial projects. My affective response differed from that of my professor. But it turned out that one didn’t have to agree with Hughes in order to elicit positive feedback. This gave me hope. By the time he assigned the last paper topic, on cooling systems for the Hanford nuclear reactors, I was fired up. I also had something to prove: nuclear reactors were my thing, and if I couldn’t do a good job with this assignment, I was in big trouble. I went all out. Not until much later did I appreciate the brilliance of Hughes’s pedagogical strategy. Because he had mined those same primary sources himself, he could provide deep, detailed feedback. I learned more about the historian’s craft in a semester with him than I had in the previous two years.
As part of this intense, source-based training, Professor Hughes insisted that we attend to visual material. Every class session—sometimes more than once—he would intone, “I cannot overemphasize the...