topic

• Hydrology2
• Aqueducts1
• Population1
• Watersheds1

name

• Hering, Rudolph, 1847-19232
• Philadelphia (Pa.). Water Department2

collection

• Maps of North America2

place

• Pennsylvania2
• Philadelphia2
• Philadelphia (Pa.)2
• Philadelphia Region2
• Philadelphia Region (Pa.)2

genre

• Maps2
• Thematic maps2

publisher

division

• Map Division2

type

• cartographic2