Publisher's Note Shows how A.C. Gilbert's Erector Sets evolved over 20 years to become one of the most popular and enduring toys of all time. Traces the history of Erector Sets from 1913 to 1932. with detailed listings of component pieces and current market values for each set. By William M. Bean and A1 M. Sternagle. 8 1/2 x 11; 160 pgs.; 80 b&w and 80 color photos; 20 diagrams and 23 charts; hardcover.