Text and numerous detailed illustrations introduce and explain the scientific principles and workings of hundreds of machines.

"In 1947, an unusual object crashed in the New Mexico desert and was recovered by the Roswell Army Air Field officers. People everywhere began to speculate what the object could be. Could it possibly be a flying saucer? Would that be proof of aliens and life beyond Earth? Even decades later, some people still believe that the Roswell Incident is the most famous UFO sighting ever. Still, those who worked at the airfield insist it was just a weather...