[Exhaust system on roof.]
[Factory building, machinery on roof.]
[Interior of unidentified building, possibly a factory.]
[Factory building.]
[Heating control valve on 17th floor of unidentified building.]
Apartment building. Penthouse roof terrace
[Roof of building.]
[Interior, detail of meters.]
[Interior, boiler room.]
[Camera factory.]
Interior, shoe factory with man at machine
Interior, shoe factory with woman at machine