Five weeks' study of astronomy ..
Young, Charles A. (Charles Augustus), 1834-1908; Comstock, George Cary, 1855- [from old catalog]; Ball, Robert Stawell, Sir, 1840- [from old catalog]; Flammarion, Camille, 1842-1925; Jacoby, Harold, 1865- [from old catalog]; Hopkins, William John, 1863- [from old catalog]