Centre Square Water Works, Frederick Graff, Sr. Plans, 1799
Centre Square Water Works, Latrobe Plans, 1799
PWD Drinking Water Treatment diagram
Steam engine drawing, Frederick Graff Sr., 1815
Fair Mount Water Works engine house, 1819
Grit Chamber, Essen, Germany
“Philadelphia Underground,” Jan. 29, 1961
PWD water tech at the Philly Home Show, 1960 (detail)
State Street pipeline construction, 1904
Belmont Filters construction, 1903