Necessity is the mother of invention... and sleepy Sloth and little Sengi, an elephant shrew, need to escape the confines of their zoo enclosure. The furry friends construct various scrappy but clever escape contraptions in this funny, interactive book by Caldecott artist David Macaulay (Black and White; The New Way Things Work).
How Machines Work: Zoo Break! lucidly explains the workings of simple machines in a delightfully elaborate way. Readers can peer into the clear plastic window of the cover itself and see a tunneling gear mechanism, then turn the gear to make the sloth go up and down. The first spread explores the efficiency of an inclined plane, as Sloth and Sengi stack a bunch of junk up against the zoo fence as a makeshift escape ramp. It might have worked, if Sengi's tail hadn't twitched, causing the napping sloth to swat him, causing the ramp to collapse! (A pop-up section reveals an angry zookeeper--he has to clean it up.) Each spread is a colorful visual feast of Macaulay's appealing pen-and-ink drawings, with insights into wedges, zippers, seesaws, catapults, levers, wheels, pulleys, cranes and more--all infused with the comical antics of Sloth and Sengi and at least one interactive element. Endearingly shameless puns abound, from "Living on the Wedge" to "A Wheely Bad Idea." Some of the escape attempts are quite nerve-wracking, such as when they try to pull down the fence using an upside-down cart, and the fence lands on Sengi.
This ingenious, entertaining, sturdily built book is sure to get the wheels turning for young engineers-in-the-works. --Karin Snelson, children's and YA editor, Shelf Awareness