Winning the Metal: Ore Mills of the West
Multiple pieces of equipment were in the mills to facilitate extraction and the following account provides one with a verbatim account from Waldo Twitchell the assayer at the Vulture Mine in Arizona, of their mill operation in 1912: "The new mill was erected in 1910, at a cost of about $80,000. The capacity is about 100 tons of ore a day.