Since J.C. Darley, the other signatory of the drawing, was only eight to twelve years old at the time the plan and elevation of the theatre were drawn, it seems reasonable to conclude that Nisbet was the "master," Darley the apprentice.
[See John R. Wolcott, "Philadelphia's Chestnut Street Theatre: A Plan and Elevation," Journal of the Society of Architectural Historians, October 1971. Vol XXX, no. 3. pp. 209 - 218.]