Wolcott believes that this omission must be attributed to J.C. Darley, whom Wolcott believes to have been an apprentice draftsman.

The arguement is developed fully in John R. Wolcott, "Philadelphia's Chestnut Street Theatre: A Plan and Elevation" in the Journal of the Society of Architectural Historians, October 1971. vol.XXX, no. 3. pp. 209-218, an essay which establishes the relationship between the so-called Nisbet-Darley plan and elevation of the first Chestnut Street Theatre.