A popular science resource last published in 2000 has received a small dose of updating. Arrangement is topical, with 10 chapters covering subjects such as Planet Earth, Human Biology, and Conservation and the Environment. Within chapters, following a brief introduction, an average of 27 entries cover a variety of smaller topics. Most entries extend over two pages and are equal parts text and colorful photographs, drawings, diagrams, cutaways, and other illustrations that are sure to draw interest. Each chapter closes with a page of Facts and Figures. All topics are cross-referenced to entries containing related material. A Ready Reference section in the back of the volume includes units of measurement, conversion tables, geometric shapes, and brief descriptions of important scientists and discoveries. A two-page glossary has a sidebar devoted to computer terms. The topical arrangement makes a good table of contents and index essential. The table of contents is clearly laid out and easy to browse, but students may be frustrated by the index. Fourteen page references are provided for telescope and six for television, for example, but the pages for the sections that specifically deal with these topics are not called out in any way. We found most evidence of updating in the Space and Time chapter, where small portions of text related to space exploration have been revised, and the number of moons in the solar system has been changed to reflect recent discoveries. Changes have been made to the Facts and Figures pages; for example, several lists of Key Dates now include twenty-first-century advances. Providing students with current science material is essential, and though the volume has not been extensively revised, libraries should acquire it to replace the previous version. This attractive, browsable, reasonably priced encyclopedia definitely has a place beside titles offering more depth, such as the six-volume New Book of Popular Science.

Gr 5-7 Aside from minor editorial tweaks and small quantities of new materialreferences to the end of the space shuttle program, for instance, and to Japan's 2011 earthquake and damaged Fukushima reactor-this update of the 2006 second edition remains largely unchanged. As in the earlier work, the sciences are divided into 10 topical chapters ranging from "Space and Time" to "Conservation and the Environment." Within the chapters, two- to three-dozen selected subjects are given a spread each of concise exposition and generally informative, sharply reproduced photos and schematic diagrams. Each chapter closes with a crowded page of summary facts, and a final section of back matter contains thumbnail portraits of famous scientists and inventions, formulas for calculating the areas of geometric figures, conversion tables, and like features. There is at least one obvious typo ("Two million people worldwide now access the Internet") and a brash claim that humans are "the most successful of all creatures." Examples of unsystematic coverage and updating include no discussions at all of quarks, quantum theory, streaming video, smartphones, cloud computing, corporate space programs, element 117 (isolated in 2010), or plasma as a fourth "state" of matter. Furthermore, though frequent cross references and a large index facilitate access to most of the content, the index includes only spotty coverage of the illustrations and fails to list the earthquake and reactor mentioned above. At best, a marginal candidate for classrooms with limited or no access to web resources, or to replace a worn copy of the previous edition. John Peters, formerly at New York Public Library