How Do Big Rigs Work?

K-Gr 2—A particular focus on engines, wheels, and other components set these unusually informative introductions apart. Silverman steers clear of potentially intimidating terminology like "internal combustion" and "hydraulic" but describes in lucid detail how pistons drive crankshafts, fluid pressure lifts a fire ladder, friction affects speed and control, and various design elements counteract air resistance. The mix of close-ups and wider angled views on every page are both helpful and stimulating—and, as a plus, show women on a tank's crew or driving big rigs and monster trucks. Each volume closes with a labeled diagram, a set of "Fun Facts," and a relatively generous set of further resources. A poorly expressed claim in Trains that it "takes little energy to pull heavy trains because there is little friction" aside, all of the volumes merit consideration either on their own or as upgrades for relevant titles in Lerner's "Vroom! Vroom!" or "Mighty Movers" series.