The gentleman in the jacket and bow tie at the bottom of the photograph, probably a site superintendent for steel erectors Post & McCord, looks on as the mast of a stiff legged derrick is placed. The lower end of the mast will be placed on the cast-iron plate bolted to the timbers to the left in the photo. The leg of the derrick rests on the temporary shoring and provides a temporary platform for the superintendent to observe the work.