Public domain
Steel production. The gas main and gas valve chambers of a blast furnace serve important purposes in the production of iron for steel making. Carnegie-Illinois Steel Corporation. Farrell, Pennsylvania
From the collection of Library of Congress. Free to download, adapt and use — no permission needed.
Credit lineSteel production. The gas main and gas valve chambers of a blast furnace serve important purposes in the production of iron for steel making. Carnegie-Illinois Steel Corporation. Farrell, Pennsylvania. 1941-01-01. United States. Office For Emergency Management, Palmer, Alfred T.. Farm Security Administration/Office of War Information Collection, Library of Congress. Public domain.