[Factory building, structure on roof.]

[Heating control valve on 17th floor of unidentified building.]

[Machine room.]

[Interior, possibly a basement, with unidentified equipment.]

[Interior, boiler room.]

[Brick wall cut-away with embedded drainage pipe.]

[Interior, view of air ducts.]

[Interior, detail of air ducts.]

[Interior of unidentified building, possibly a factory.]

29th Street pier. S.S. Mobile City ship, Isthmian Line. Sump pump pipes

[Interior with machinery.]

[Interior, boiler room.]

[Interior, boiler room.]

Apartment building. Penthouse roof terrace

[Interior, detail of meters.]

[Interior, boiler room.]

National Lead Company. View of lead flashing on roof

[Interior, radiator manufacturing shop.]

View of heating system for water tanks on roof of building, outside.

[Street excavation.]