Reviewed by: Pushing the Limits: New Adventures in Engineering Rudi Volti (bio) Pushing the Limits: New Adventures in Engineering. By Henry Petroski . New York: Alfred A. Knopf, 2004. Pp. xxii+288. $25. It is likely that most readers of T&C have read at least one of Henry Petroski's books on engineering and design. A few of these books have dealt with important though mundane items like paper clips and pencils. Pushing the Limits, his twelfth book, deals with designs at the other end of the scale: massive, even grandiose, structures that have taken their creators into perilous engineering territory. Nearly half the book is devoted to bridges, which are some of the most visible artifacts of adventurous engineering. Individual chapters cover, in varying levels of detail, structures as varied as Robert Stephenson's Britannia Bridge, London's Tower Bridge, and a small floating bridge in Vermont. Bridges are some of the most aesthetically satisfying technological accomplishments, in part because their designers often have concerned themselves with the artistic merit of their creations. Artistry, of course, has to be coupled with technical competence, and Petroski does a good job of describing the engineering challenges that had to be overcome in the course of designing and constructing each bridge. The remainder of the chapters fall under the heading of "other things." Here we meet such varied accomplishments as the Guggenheim Art Museum in Bilbao, Spain, London's Millennium Wheel, and the innovative skyscraper designs of Fazlur Khan. For many readers, the variety of the topics presented will make these pages the most engaging part of Pushing the Limits. With a few exceptions, the book covers works of engineering where the limits were pushed successfully. Two chapters cover structures that suffered catastrophic failures with tragic results: the breaching of Southern California's St. Francis Dam, and the collapse of a log pyramid built by students at Texas A&M University that was intended to fuel a massive bonfire. A third chapter that analyzes the destruction of the World Trade Center's towers covers a failure that few had foreseen, but will nonetheless affect the design of skyscrapers for years to come. Another chapter narrates the author's reportage of a colossal work-in-progress, the Three Gorges Dam in China. [End Page 181] This enormous project is for the most part presented as a success in the making, although not everyone would agree with this evaluation. All of the chapters in Pushing the Limits originally appeared over a span of ten years as articles in The American Scientist. Because they were published separately, each of them can be taken as a stand-alone piece, allowing readers to dip into individual chapters in accordance with their own interests. At the same time, however, this episodic quality results in the book's greatest shortcoming—the absence of a framework to hold everything together. Given the author's deep understanding of engineering practices and the forces that drive them, this would have been an excellent opportunity to reflect on the economic, aesthetic, technical, and personal motivations that cause the limits to be pushed. As the chapters on failed engineering projects indicate, sometimes the limits push back with a vengeance, but the reasons for this happening remain for the most part unexplored. One of Petroski's other books, To Engineer Is Human, carries the subtitle The Role of Failure in Successful Design, so this is an issue that he has confronted before. A chapter specially written for this new book would have been an appropriate place for a further consideration of the underlying causes of success and failure. Instead, the last two chapters consist of previously published articles that celebrate more engineering accomplishments of the past. Pushing the Limits also can be criticized for some minor sins of omission and commission. In regard to the first, many of the narratives would have benefited from illustrations and diagrams like the one used to illustrate the structural principles employed in the design of the Dorton Arena in North Carolina. For the latter, the final chapter can be taken to task for its perpetuation of the canard that the U.S. Commissioner of Patents claimed at the end...