Ball Mills Before the gold could be extracted, the rock was turned to powder. Depending on the size of the steel balls inside the mill, the rock would be reduced to a certain size. So, multiple mills were usually used in stages. Related Similar Images ...based on the tags: collapsing, doors, gears, machinery, mills... A side door for the shop area with ivy crawling toward it. One of my favorite visual feature of grain elevators, especially big ones, is how they repeat. When I moved from the roof back into the upper floors of the distillery, the plants growing out of the masonry caught my eye. It’s 60 feet up, but looks like it could be an old wall. An elevator to bring big somethings into the basement, it seemed. Nearby were the plant firetrucks, still ready to go. I hope they were saved. The incinerator’s hardened steel door… useless, but still sexy in a heavy-industrial kind of way. A machine to cast copper billets. Tucked-into the side of the concentration mill… these machines were meant to crush underground rock into a fine dust for mineral extraction. One of a few rolling workbenches to keep the thousands of pulleys, cogs, and belts working properly. Installed in 1904 at the center of the plant, this is one of two batteries of boilers. Being in Oshkosh, heat was very important to keeping labor moving in the cold months.