[Interior, detail of air ducts.]

[Interior, view of air ducts.]

[Interior of unidentified building, possibly a factory.]

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

[Factory building, structure on roof.]

[Exhaust system on roof.]

60 Wall Street [70 Pine Street.] Cities Service Company. Interior, Riggs-Distler Heat units

325 East 79th Street. Penthouse garden, 17th floor.

17-19 West 17th Street. Loft building.

26-32 West 17th Street. Loft building.

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

[Interior, boiler room.]

[17-19 West 17th Street.]

[Machine room.]

12 East 86th Street. Croydon Hotel, 17th floor penthouse garden, Mrs. Zoylner.

138-140 West 17th Street. Loft building.

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

Empire State Building, heating and ventilating equipment, main steam control room.

Fourth Avenue and E. 17th Street. Everett Building.

[Interior, detail of meters.]