[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.

26-32 West 17th Street. Loft building.

[Interior, boiler room.]

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

138-140 West 17th Street. Loft building.

[17-19 West 17th Street.]

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

17-19 West 17th Street. Loft building.

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

[Interior, detail of meters.]

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

90 Church Street. U.S. Federal Building and Post Office. Interior, 17th floor machine room

17th Street and 5th Avenue. Mott Iron Works Building.