Seconds, minutes, days, weeks, months, years, forever--it's surprising how arbitrary our temporal bookkeeping is, owing as much to lore as to science. Branley ranges through history, astrology, astronomy, and modern technology to explore how we've arrived at our hodgepodge of nomenclature and method, while Weber's drawings amplify and extend the text. Surprisingly, the much-experienced author occasionally approaches but then fails to draw a conclusion--e.g., that we have 12 months because there are 12 full moons in a year. Clocks are given short shrift: pendulums aren't mentioned, and there's an anomalous drawing of a 10-hour clock with what looks like a 12-hour alarm. Nevertheless, there's a lot here for either an individual reader or a class. Bibliography; index. (Nonfiction. 8+)
