The History of the Tower

The present, permanent Thomas A. Edison Memorial Tower was designed in 1937 by Gabriel Francois Massena and Alfred F. duPont of Wilmington, Delaware. Other notable commissions of the firm of Massena and duPont include:

• Sunken Garden and Carillon Tower at Nemours, Delaware
• United States Post Office, Wilmington, Delaware
• United States Federal Building, Wilmington, Delaware
• City Hospital, Wilmington, Delaware

Massena and duPont chose the Art Deco style for the Tower shaft, which tapers upward to the monumental replica of Edison's first practical incandescent bulb. The effect is to focus attention upward to the light at the top, as well as enhance the sense of height and monumentality. A brochure, published in 1938, the year of completion and dedication of the Tower, contains the following description:

The use of architectural precast panels was a relatively new concept in 1937. The panels were created by the Earley Studio of Rosslyn, Virginia. John Joseph Earley, second owner of the studio, was a pioneer in the field of exposed aggregate precast concrete. In fact, he coined the term "architectural concrete" to describe the exposed aggregate surface. Earley's work set the basis by which modern standards for precast concrete are written. One of his most significant achievements was the development of step-grading (commonly referred to as gap-grading today), which provides uniformity, maximum density of coarse aggregate and color control in exposed aggregate courses. He was awarded a patent for this concept in 1921.

In addition to precast concrete, J. J. Earley also developed a method of concrete mosaic decoration which could be applied to structure in the field by plastering with a step-graded mix and exposing the aggregate before the plaster had hardened. Other notable projects under J. J. Earley's tenure for which the Earley Studio contributed architectural concrete include:

• The Fountain of Time. Chicago, Illinois. 1922
• Permanent Replica of the Athenian Parthenon at Nashville, Tennessee. Exterior, 1922–1925
• New campus for the Louisiana State University at Baton Rouge. 1924–1926
• The Temple of Light, the Baha'i House of Worship at Williamette, Illinois. Exterior, 1932–1942.²

The Tower, which rises 117' – 8" above the Terrace, is topped by a 13' – 8" high monumental Bulb of Pyrex glass segments. The Terrace is set about 3' – 6" above site grade, given a total height of 134' – 10" above site grade. The Tower interior contains four levels:

• Eternal Light Level, at Terrace grade, approximately 12' - 2" high, containing the Eternal Light Room and a utility room
• Amplifier Room Level, 9' – 4" high, containing electrical equipment for the sound system, including speakers
• Intermediate Level, extending 67' high
• Loudspeaker Room Level, at the loudspeaker grilles, 16' – 11" high containing speakers
• Access Room, a 9' – 9" high compartment below the Bulb

Construction of the Tower continued from May 17, 1937, through February 10, 1938.³ The Tower was dedicated on February 11, 1938. The Tower was presented as a gift of William Slocum Barstow to the Thomas Alva Edison Foundation Incorporated on behalf of the Edison Pioneers.⁴

The Edison Memorial Tower was constructed at a total cost of $134,200.02, excluding the electric organ and loudspeakers.⁵ The largest single expense was the mosaic concrete panels.

The Edison Memorial Tower was listed on the State and National Registers of Historic Places in 1979. The site possesses historical and cultural significance for the events that took place there; the Tower itself possesses architectural significance for its stylistic expression, construction techniques, and use of architectural concrete. The Tower possess cultural significance as a monument, not as a government-sponsored monument to a battle or political hero, but as a privately financed monument to a man of science. The Edison Memorial Tower is symbol of the greatness that the public saw, and continues to see, in Thomas Alva Edison and his scientific contributions.

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