Peeking Under Your Skin

Gr 2–4—These "peeks" take a system-by-system approach to their subjects—pairing informal but pleasantly specific commentary to cartoon-style cutaways and diagrams. Though the illustrations are not consistently to scale, in all but Hood they are formatted sideways for an effective sense of depth. Underground begins with images and descriptions of the layers of soil, continuing on past bedrock to fossil fuels, tectonic plates, volcanoes, and the mantle to reach Earth's outer and inner cores. City pays tribute to the importance of civil engineers as it peels away generic pavements to expose pipes, conduits, mains and submains, fossils and artifacts, train and traffic tunnels, and even crypts and catacombs. The back matter in each volume includes several Common Core-linked questions. The texts can occasionally verge on the simplistic; for example, in Skin, involuntary muscles, "move without the brain's messages." Still, the overall level and accuracy of detail make the series a worthy addition.