In 1911, Boris Rosing and his understudy Vladimir Zworykin made a framework that utilized a mechanical mirror-drum scanner to send, in the most natural sounding way for Zworykin, "extremely rough pictures" over wires to the "Braun tube" (cathode beam cylinder or "CRT") in the recipient. Moving pictures were impractical in light of the fact that, in the scanner: "the responsiveness was sufficiently not enough and the selenium cell was very laggy