HOW MACHINES WORK

A pair of would-be escapees discovers the uses and misuses of simple machines in this slapstick STEMwinder.

Bored with their confines, Sloth and Sengi (aka “elephant shrew”) concoct a series of unlikely devices designed to get them over or under the walls. With Sloth providing the muscle (when awake), Sengi proves himself a small, furry engineering genius by inventing an inclined plane, a springboard, a wedge, a winch, single and double pulleys, a tunneling auger, and more from miscellaneous found materials. Macaulay depicts each project with his customary casual exactitude and festoons them with descriptive notes. These point out significant elements such as “fulcrum” and “spur gears,” joining directional arrows and lucid explanations of how each uses mechanical advantage to redirect effort or force. Some, such as the heavy-duty gear-driven lift under a window on the front cover and a seesaw that requires assembly, are working models. With much use of flaps, pop-ups, and inset booklets, the author also expands on the comical plotline with glimpses of construction machinery, hydraulics, and several types of levers in action. He also includes simple machines in various combinations—in a bicycle, a crane, and, in a big climactic foldout, a truly Rube Goldberg–ian construct that almost works.

“So clever!” murmurs the elephant shrew, admiring himself in a mirror. No argument here.