cover image How Machines Work: Zoo Break!

How Machines Work: Zoo Break!

David Macaulay. DK, $19.99 (32p) ISBN 978-1-4654-4012-9

Expertly blending comedy with a substantive look at physics and mechanics, Macaulay stages a lesson about simple machines at a zoo, where a sloth and shrew are attempting to escape. Short paragraphs explain the basic engineering behind levers, wheels, pulleys, and more (“A lever is simply a bar that tilts on a fulcrum”) as the two animals comically test out their contraptions in episodic sequences (readers can even build a seesaw and try to launch the sloth and shrew over a fence). A final, foldout spread reveals their most elaborate machine yet, which resembles a roller coaster and incorporates all of the devices they have used so far. It doesn’t work as they hoped, but readers will be delighted to see their ingenuity rewarded. Ages 7–10. (Nov.)