3Machines developed for use on land change the way the world works. When tanks were first built, they changed the course of a war. Cars changed how people move--and now electric cars are doing it again! Mag-Lev trains are amazing feats of engineering that move faster than anyone 100 years ago would have thought possible! Readers of this compelling volume explore the science and engineering behind many kinds of machines that go on land, including full-color photographs and helpful diagrams.