Paris, tube under the channel -- London, satellite spinning above cables on the ocean floor -- New York, concrete ribbons across undulating land -- San Francisco, silver wings soaring across the Pacific -- Tokyo and Seoul. Etched against the sky are the graceful towers of mighty bridges, the broad glass and steel fronts to massive buildings, the tall slender stacks of industries exhaling; and traced on the surface are the intricate patterns of people and their machines; and buried below are the tubes and tunnels, water pipes and power conduits and communication networks along with concrete caissons and piles that penetrate towards the earth heart seeking assurance of a solid foundation. There in the bowels of the earth lies the entrails, and there piercing the sky towers the head of civilization; but here stands humankind, the heart and mind of that civilization, asking ourselves are we standing on feet of clay?