In irregular halting lines. I remember the anxiety of never feeling sure whether the magnetic needle--Method of reversing the current--Sounding instruments--Telegraphic relays--Recording telegraphs--High-speed telegraphy 127 Chapter VII.--WIRELESS TELEGRAPHY. The transmitting apparatus--The receiving apparatus--Syntonic transmission--The advance of wireless messages, 143. Talking-machines, 310. Tapper in wireless.