Wissahickon Pipe Aqueduct, Roxborough to Mt. Airy, 1868
Map Lovers’ Monday: 1891 Water Supply Plan
Down Under III: A walk in the Dobson’s Run Storm Relief Sewer, June 15, 2010
Requiem for a stream: A brief history of Dobson’s Run
Down Under, Part 2: Beaver Creek as it appears today
Half a Century of Clean Water
Centennial Exhibition situation plan, 1876