[Construction of the New York World's Fair site, with the steel frames of the Trylon and Perisphere in the background.]

[Construction of the New York World's Fair site, with the frames of the Trylon and Perisphere in the background.]

[New York World's Fair site under construction, with the frames of the Trylon and Perisphere in the background.]

[New York World's Fair site under construction, with the frames of the Trylon and Perisphere in the background.]

[Construction of the Trylon and Perisphere, New York World's Fair site.]

[Construction of the Trylon and Perisphere, New York World's Fair site.]

[Construction of the New York World's Fair site, with the frames of the Trylon and Perisphere in the background.]

[Construction of the Helicline, Trylon and Perisphere, New York World's Fair site.]

[Construction of the Trylon and Perisphere, New York World's Fair site.]

[Construction of the Perisphere and Trylon, New York World's Fair site.]

[Electrical Products building with the frame of the Trylon in the background, New York World's Fair site.]

[Construction of the Trylon and Perisphere at the New York World's Fair site.]

[Construction of the Trylon and Perisphere at the New York World's Fair site.]

[Construction of the Trylon at the New York World's Fair site.]

[New York World's Fair. Pile driver with Perisphere and Trylon in background. Construction view.]

[Construction of the Trylon, Perisphere and Helicline at the New York World's Fair site.]

[Construction of the New York World's Fair site.]

[Construction of the New York World's Fair site.]

[Construction of the New York World's Fair site, showing the Ford pavilion's spiral driveway and the steel frame of the Trylon in the background.]

[Construction of the New York World's Fair site.]