Description: ÒProduction of Tungsten in South America in 1913, of Vanadium in 1912, and of Molybdenum in 1915É Each dot represents 1 per cent of worldÕs production. A cross represents less than 1/2 per cent of worldÕs production. — Department of the Interior, 1921 Source: Department of the Interior , World Atlas of Commercial Geology (Washington, DC: Department of the Interior , 1921) Plate 27 Map Credit: Courtesy the private collection of Roy Winkelman
