Last semester I received a review copy of “Shigley’s Mechanical Engineering Design,” and it prompted me to reflect on how engineering textbooks have generally changed in bulk, style and content since I was a student, more than four decades ago. At that time, I used the first edition of “Shigley,” which still stands demurely on my bookshelf.

“Machine Design,” as it was then called, was originally published in 1956. The text’s title changed to “Mechanical Engineering Design” with the second edition, coauthors were added with the fourth and with the latest (the eighth) Shigley’s name has moved from being among the book’s authors to qualifying its title.

Bound in gray buckram, the cover and spine of the text I used were as reserved and dignified as those of any law book. The slick cover of the new edition, which carries a copyright date of 2008, sports a cutaway illustration of a gear box and a finite-element model of a shaft.

The mechanical attributes of the earliest and latest editions stand in sharp contrast. Whereas the progenitor measures about 6-by-9-by-1 inch thick, its youngest descendant is 8-by-10-by-1.5. In other words, the first edition could fit easily inside a hollowed-out eighth.

But we should not judge a book by its cover or size, but by its contents. The new “Shigley” has an abundance of contents, including a “brief contents,” which is essentially a list of chapter titles; an extended “contents,” which also lists section titles; and a listing in the preface of chapter-by-chapter “content changes and reorganization.” And, as if this were not enough, each chapter begins with a “chapter outline,” which repeats information on the contents page.

This “classic text” now has 1,059 pages, compared with the original’s 523. This is remarkable, given that today’s curricula generally allow for fewer courses than did those of eight editions ago. As I recall, we used “Shigley” for two full semesters. Still, could I have learned as much about design from the smaller book as today’s students might from the larger?

The first sentence of the introduction to the “Shigley” I used was straightforward: “To design is to make decisions.” Concrete examples followed immediately, with Shigley pointing out that while a contemporary Ford and a Chevrolet each represented a “successful solution to the same design problem,” they differed in appearance, piston size and valve arrangement. Shigley elaborated on such familiar examples to emphasize that design decisions determine the nature and quality of a design. He also observed that, “Decisions are always compromises.”

In contrast, the first sentence of the eighth edition reads, “Mechanical design is a complex undertaking, requiring many skills.” This is a different emphasis and, instead of being presented with concrete examples, the reader is given still another version of the book’s contents. Then we read, “To design is either to formulate a plan for the satisfaction of a specified need or to solve a problem.” Besides seeming either uncertain or redundant, this is vague and lacks concision. It is only after another couple of sentences of generalities that we read that design “is also a decision-making process.” We have to wait a while for examples as pointed and familiar as automobiles.

There is much to be admired in the new edition of “Shigley.” But during the same period that the size and contents of engineering textbooks like this have expanded, engineering curricula have been compressed. It is paradoxical.

Henry Petroski is the Aleksandar S. Vesic Professor of Civil Engineering and a professor of history at Duke University. His latest books are “Pushing the Limits: New Adventures in Engineering” and “Success Through Failure: The Paradox of Design.”

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