This book is part of a book series called Searchlight Books-How Do Simple Machines Work? .

This book has been graded for interest at 8-11 years.

There are 40 pages in this book. This book was published 2011 by Lerner Publications (Tm) .

Sally M. Walker is the author of the ALA Notable Blizzard of Glass: The Halifax Explosion of 1917 . She is also the author of Written in Bone , Fossil Fish Found Alive , and Secrets of a Civil War Submarine , which was awarded a Sibert Medal. She lives in Illinois.