[Exhaust system on roof.]

[Factory building, machinery on roof.]

[Interior of unidentified building, possibly a factory.]

[Factory building.]

[Factory building.]

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

[Interior with machinery.]

[Interior, boiler room.]

Interior, shoe factory with man at machine

Interior, shoe factory with man at machine

National Lead Company. View of lead flashing on roof

Woolworth Building, Under No. 3 Barclay [Construction zone.]

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

Apartment building. Penthouse roof terrace

[Roof of building.]

[Interior, detail of meters.]

[Interior, boiler room.]

[Interior, boiler room.]

Centre Street and Pearl Street. U.S. Federal Courthouse. Interior, detail of roof showing lead installations

[Workers in an unidentified factory.]