Fifteenth annual report of the United States geological survey to the secretary of the Interior 1893-94 Fifteenth annual report of the United States geological survey to the secret... by Powell, John Wesley, 1834-1902, Shaler, Nathaniel Southgate, Ward, Lester Frank, 1841-1913, Lawson, Andrew C., Hise, Charles Richard van, Bayley, William Shirley, 1861-1943, Smyth, Henry Lloyd, Williams, G. H., Keyes, C. R.