


Models of Change

Sometimes the backside is the best side

Buried Treasures No. 1: The Franklin Sugar Refinery

Map of Frankford Borough, 1845

Sewer systems, City of Philadelphia, 1927 and 1929

Early visions of Philadelphia’s airport

Drawing Dock Creek

Petition of manufacturers along the Schuylkill River in Philadelphia for a new upstream water supply, 1868
New Plan of Philadelphia, John A. Paxton, 1811
