BULLDOZER: a large, powerful tractor having a vertical blade at the front end for moving earth, tree stumps, rocks, etc.


  I heard the most fascinating brief story on NPR the other day. It was about the design and development of the bulldozer, that big, yellow behemoth that is ripping up the earth as you travel along the highway, tearing down the abandoned grocery store in the next neighborhood, or leveling the back yard where […]

CHRYSALIS [KRIS-uh-lis]: the hard shell covering surrounding a caterpillar which is becoming a butterfly


Every middle school science student has learned about the chrysalis.  If the science teacher is creative, the class has spread out in the fields to find one hanging on a branch.  It is a tubular, hard shell, hanging only by a thread.  Some are transparent; others are not. When taken back to the classroom and […]