The Usborne Book of How Things Work Author:Martyn Bramwell, David Mostyn (Illustrator) What do a clock, a car engine, and an eggbeater have in common? All three use gears to create motion. Curious kids can read the text, study the illustrated pictures and diagrams, and even build their own set of gears to figure out why gears are so useful and why the number of teeth is important. Many more simple machines are examined as well, wi... more »th particular attention to how each is used in more complex everyday objects. Each two-page spread focuses on a different physical science concept, such as air pressure, slopes and screws, balancing, steam power, and much more. An abundance of examples show readers how this concept has been applied to tools and machines to make jobs easier. To bring each concept to life, activities are featured for each machine so kids can see “how it works.” An excellent tie-in with any study of physical science, these “wow” projects require only household objects and allow kids to see how big “complicated” pieces of machinery and vehicles work at a simpler level.« less