A great idea: The story behind the Brooklyn Bridge, Golden Gate, and a score of other marvels of late-19th and 20th century engineering genius. If only Petroski (The Pencil, 1990; The Evolution of Useful Things, 1992) had spared some of the detail and added more diagrams to illustrate basic principles and controversies. Indeed, civil engineering was the daughter of the Industrial Revolution, an empirical science evolved to meet the needs of rapid transport by rail and internal combustion engine. It was by no means certain that designs for longer and longer spans and higher and higher towers, using newfangled raw steel and concrete materials instead of masonry, would literally hold up. And failures there were. Cantilevered bridges were out following the collapse of a bridge in Scotland; suspension bridges had to fight their way back to respectability after ""Galloping Gertie""--the Tacoma Narrows Bridge--torsioned itself to death in high wind. But it is the people Petroski cares about: the engineer-dreamers whose names, except perhaps for the Roeblings of Brooklyn Bridge fame, are unknown. So his chapters center on half a dozen greats: men like James Eads, who bridged the Mississippi; Gustav Lindenthal (New York's Hell Gate); Othmar Ammann (the George Washington Bridge); and David Steinman (Marcinac Bridge), the names in parentheses only the best known of their contributions. They, their partners and rivals, the politicians, bankers, and public interest groups, the construction workers and the general public animate the tales that Petroski tells. They are part of his ongoing crusade to celebrate engineers--in this case a particularly ardent, outspoken, and ambitious lot who truly dreamed of spanning the world. To his credit, Petroski paints his heroes' flaws as well as their virtues. Had he more simply explained the flaws and virtues of the various bridge designs, he would have succeeded not only in honoring engineers but also the science of engineering.