 On August 25, 1934, Farnsworth gave the world's first public demonstration of a complete, all-electronic television system, which included his image dissector, at the Franklin Institute in Philadelphia, Pennsylvania.In April 1933, Farnsworth submitted a patent application entitled "Image Dissector", but which actually detailed a cathode ray tube (CRT) camera tube.By late 1930s, dissectors were replaced by more efficient iconoscopes.