Anyone who's ever gotten an inexplicable kitchen utensil in a Christmas stocking–and gone through the embarrassment of asking the gift-giver what it's supposed to be–will appreciate the work of Duke University engineering and history professor Henry Petroski, who contends that a well-designed object should reveal its own purpose. For more than a decade, Petroski has converted his interests and pet peeves into a series of popular-science texts like The Evolution Of Useful Things and To Engineer Is Human: The Role Of Failure In Successful Design. His formula is simple and entertaining: He juggles anecdotes and observations about commonplace inventions, and comes to thought-provoking conclusions about how daily life is influenced by prosaic gadgetry. Petroski's new book Small Things Considered recounts the creation and refinement of the likes of shopping bags and cup holders, considering how items that seem to be ideally functional are constantly being improved, and yet still retain the flaws of compromise. Reducing the process of design to its fundamentals, Petroski works methodically through everyday procedures like going out to dinner with friends, to show the ways people approach even the simplest plans with unreasonable expectations that become progressively tempered. Small Things Considered's vision of a world where consumers make do with ergonomically improved toothbrushes that no longer fit into their bathroom holders might be depressing, were it not for Petroski's sense of admiration for humans' ability to "adjust the sides of our brains the way we adjust the faucets on our sinks, taking care not to be overly hot or overly cold." Much of Small Things Considered is dedicated to pointing out how people accommodate such illogical bits of design as the positioning of light switches on walls and the inverse arrangement of telephone and calculator number pads. At times, the book becomes a catalogue of lost or soon-to-be-lost design ingenuity, from paper sacks to rotary telephones (which, Petroski notes, many people under 15 can't figure out how to use). It's mildly sobering, and a diverting reminder of how even the "new and improved" will one day be improved in turn.