A large drum still remains in this section. I assume the metal tank was once used to store chemicals or as a holding tank to mix a pulp slurry then used to make paper. The video below details the paper making process at the Neenah Paper Mill in Wisconsin. At the 30 second mark a smiliar looking large drum called a "pulper" can be seen, which is used to mix recycled paper into a pulp slurry. I imagine the same process was used at the Curtis Mill.