Fair Mount Water Works engine house, 1819
Dobson’s Mill, 1884, from History of Philadelphia by Scharf & Wescott
Map of Philadelphia showing Population in year 1920
Map of the County of Philadelphia from Actual Survey, 1843
Outline Map of the County and City of Philadelphia and Vicinity, 1883
1779 Revolutionary War-era map of Philadelphia and environs
Schuylkill River Hydrographical Survey 1861-66 by H. P. M. Birkinbine
Color Diagram of Plan for the Collection, Purification and Disposal of the Sewage of the City of Philadelphia
‘Gillette, All By Himself, Gets Fine New Idea On Germ Slaying’
Outhouse over the Schuylkill near Pottstown