Patents can be an interesting window into the past. On December 14, 1937, for example, U.S. Patent No. D107425 issued to Wallace K. Harrison and J. Andre Fouilhoux on a model of an architectural unit.

The design is of the Trylon, Perisphere, and Helicline, which became the central symbol of the 1939 New York World’s Fair, was reproduced by the millions on a wide range of promotional materials, and served as the fairground’s focal point.

The structures were razed and scrapped after the closing of the fair and their materials were repurposed into World War II armaments. The image and the optimism for the future they were intended to convey, however, persist in the records of the USPTO.