MIGHTY MODELS

An overview of ways that levers have been used throughout history and prehistory.

Instructions for a build-your-own catapult (and an included model) add interest, but this introduction fails on multiple fronts to provide systematic or useful information about the simple machine the device employs. For one thing, while Van Zandt does offer some unusual examples of levers in use (such as a filmmaker’s clapperboard) and properly points out how they often work in tandem with other simple machines like inclined planes and wedges, she never quite gets around to identifying the three types of levers or discussing more than a few of their distinctive capabilities. All three do appear in Breen’s busy historical scenes, colored as bright red bars to stand out, but these illustrations have issues, too. Though the author explains how “catapults” (or, more accurately, onagers) actually worked, the twisted ropes that powered them are either wrongly located, barely glimpsed, or not visible at all in the accompanying illustration of ancient Greek besiegers—some of whom aren’t even aiming their weapons at the stone wall supposedly under attack. The disconnect between text and pictures carries over to a pulley that’s described but not shown, and a lever that’s absent from a schematic view of the airplane engine throttle it supposedly controls. The illustrator does vary the skin tones slightly in the groups of smiling cartoon figures posed next to the scales, steam locomotive, and other technology from various eras.

Skips too many basics to offer any advantage, mechanical or otherwise.