<b><font size="+1">The Best Tool of the Millennium</font></b> <P> The seeds of Rybczynski's elegant and illuminating new book were sown by <I>The New York Times,</i> whose editors asked him to write an essay identifying "the best tool of the millennium." An award-winning author who once built a house using only hand tools, Rybczynski has intimate knowledge of the toolbox -- both its contents and its history -- which serves him beautifully on his quest. <P> <I>One Good Turn</i> is a story starring Archimedes, who invented the water screw and introduced the helix, and Leonardo, who sketched a machine for carving wood screws. It is a story of mechanical discovery and genius that takes readers from ancient Greece to car design in the age of American industry. Rybczynski writes an ode to the screw, without which there would be no telescope, no microscope -- in short, no enlightenment science. One of our finest cultural and architectural historians, Rybczynski renders a graceful, original, and engaging portrait of the tool that changed the course of civilization.