00331nam a22001217a 450000500170000000800410001704100080005808200080006611000310007424500430010526000510014830000100019920260803094604.0260803b        |||||||| |||| 00| 0 eng d  aeng  a620  aNational Geography Society  aThe Builders:bMarvels of Engineering/  aWashington;bNational Geography Society,c1992  a288p.