School Library Journal
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Gr 4-7-Conversational text, whimsical mixed-media artwork, and elegant book design combine to present an informative and entertaining romp through time. Succinct chapters treat a broad spectrum of subjects, beginning with the age-old human interest in measuring time, timekeeping in nature (from periodical cicadas to circadian rhythms), speculation about why early humans quantified regular changes in the world around them (Jenkins does a good job of explaining "why calendars and religion are almost always closely linked"), and the challenges of basing a calendar on astronomical observations. The story continues with descriptions of ancient calendars, the development of the Gregorian calendar, and the evolution of timekeeping devices. The final chapter briefly explains Albert Einstein's theory of relativity and introduces the possibility (and resulting chronological oddities) of traveling "at nearly the speed of light." Quite a lot of territory is covered here, but the clear, lively writing will keep readers focused, and the broad approach presents an interesting overview and invites youngsters to explore topics in further detail. Holland's precise-looking collages blend images of clocks, cultural sites, important locales, historical figures, and more to support the narrative while imaginatively interpreting the concepts and adding touches of humor. The fun continues in the layout, as the text is often shaped (like a pyramid or a planet) to echo the illustrations. Kids will find time flying as they pore over this book.-Joy Fleishhacker, School Library Journal (c) Copyright 2010. Library Journals LLC, a wholly owned subsidiary of Media Source, Inc. No redistribution permitted.

Book list
From Booklist, Copyright © American Library Association. Used with permission.

This diverting picture book addresses all manner of head-scratching quandaries kids will likely have about the concept of time: Why is it measured in such seemingly random units? When did keeping precise time become so important? And wait, what is time, anyway? It's a pretty heady subject, all right, but Jenkins and Holland go a long way toward making the investigation fun without shirking any thought-provoking dilemmas. Beginning with the cycles and rhythms of the natural world, moving into early calendar-keeping and astronomy, and finishing with rigorous scientific inquiry (and even a succinct explanation of relativity), the text traverses Egyptian, Mayan, Chinese, Greek, and European history, explaining any number of little irregularities along the way. The mixed-media cut-illustration artwork oscillates between helpful illuminations of the text and inspired Monty Python-esque lunacy, as in the opening scene of top-hatted gentlemen riding winged clocks through the sky to convey time flying when you're having fun. For kids inspired by pondering and excited by paradoxes, this book is as good an example as anything.--Chipman, Ian Copyright 2009 Booklist