The Trylon and Perisphere were two modernistic structures, together known as the "Theme Center," at the center of the New York World's Fair of 1939-1940.

Theme center

Connected to the 210 m spire-shaped Trylon by what was at the time the world's longest escalator, the Perisphere was a tremendous sphere, 180 feet in diameter. The sphere housed a diorama called "Democracity" which, in keeping with the fair's theme "The World of Tomorrow", depicted a utopian city-of-the-future. Democracity was viewed from above on a moving sidewalk, while a multi-image slide presentation was projected on the interior surface of the sphere. After exiting the Perisphere, visitors descended to ground level on the third element of the Theme Center, the Helicline, a 290 m spiral ramp that partially encircled the Perisphere.

Symbol of the 1939 World's Fair

The Trylon and Perisphere became the central symbol of the 1939 World's Fair, its image reproduced by the million on a wide range of promotional materials and serving as the fairground's focal point. The United States issued a postage stamp in 1939 depicting the Trylon and Perisphere (pictured). Neither structure survives; however, the Unisphere is now located where the Perisphere once stood.

Architects and afterlife

The Theme Center was designed by architects Wallace Harrison, Max Abramovitz and J. Andre Fouilhoux, with the interior exhibit by Henry Dreyfuss. The structures were built in Flushing Meadows Park in Queens, New York and were intended as temporary with steel framing and plaster board facades. Both buildings were subsequently razed and scrapped after the closing of the fair, their materials to be used in World War II armaments.

The word Perisphere was coined using the Greek prefix peri-, meaning all around, about, or enclosing, surrounding. The word Trylon was coined from the phrase "triangular pylon".