Thomas A. Edison, W.K.L. Dickson, and others at the "perfected" wax-recording phonograph. .Image date: 1892. Edison is at center; Fred Ott at left and Col. George Gouraud at right. Standing (left to right) are W.K.L. Dickson, Charles Batchelor, A. Theodore Wangemann, John Ott, and Charles Brown.