The height limitations of this ordinance shall not apply to
church spires, belfries, cupolas, penthouses and domes not used for
human occupancy; nor to chimneys, ventilators, skylights, water tanks,
bulkheads, similar features and necessary mechanical appurtenances
usually carried above the roof level. Such features, however, shall
be erected only to such height as is necessary to accomplish the purposes
they are to serve. No advertising device of any kind shall be inscribed
upon or attached to that part of any structure which extends above
the roof limitations.
