Bureau of City Property: Method of making and setting tree guards by John C. Lewis, City Forester and Landscape Gardener. Department of Public Works, Bureau of Surveys. [ID: 12B-589; PWD ERV: 1075952; Drawing No.: 6994], c. 1890, Drawer: Fa, Folder: 2.1. Philadelphia Water Department 12B - Drawings Donation, FP.2019.002. Fairmount Park Historic Resources Archive. https://pprarchives.libraryhost.com/repositories/2/archival_objects/4892 Accessed October 27, 2026.