As showcases of design, architecture, technology, industry and politics, world's fairs have served as overviews of society's accomplishments as well as barometers of the optimism for the future. While many of the products and ideas promoted at past fairs never materialized, many became commonplace: television, for example, was first shown at the 1939 New York fair. Similarly, while many buildings and landscapes built for fairs have become world-wide icons - the Eiffel Tower, the Crystal Palace, the Barcelona Pavilion, the Seattle Space Needle, the Buckminster Fuller Dome in Montreal - hundreds of splendid structures have been forgotten.
來源: Google Book