A similar apparatus was constructed for submarine-chasers with a standard range of conversation of over five miles. Apparatus was manufactured in large quantities in this country and all our submarine-chasers were equipped with it, as well as a great many of our airplanes and seaplanes, and we furnished radio-apparatus sets to our allies which proved of immense value in the war. This was particularly so in the case of submarine detection, when it was possible for a seaplane or a balloon to report its findings at once to submarine-chasers and destroyers, and to guide them in pursuit of submarines. The improved audion holds out a wonderful future for radiotelephony. For receiving, at least, no elaborate aërial will be needed, and with a small loop of wire, an audion or two, and simple tuning-apparatus any one can hear the radio gossip of the whole world. TELEGRAPHING TWELVE HUNDRED WORDS PER MINUTE Some remarkable advances were made in telegraphy also. During the war and since, messages have been sent direct from Washington to all parts of the world. In the telegraph room operators are connected by wire with the different radio stations along the coast and they can control the radio transmitters, sending their messages without any repeating at the radio stations. Long messages are copied off on a machine something like a type-writer, which, however, does not make type impressions, but cuts perforations in a long sheet of paper. The paper is then run through a transmitter at a high speed and the message is sent out at a rate of as much as twelve hundred words a minute. At the receiving-station, the message is received photographically on a strip of paper. The receiving-instrument has a fine quartz thread in it, which carries a tiny mirror. A beam of light is reflected from the mirror upon the strip of sensitized paper. The radio waves twist the quartz thread ever so slightly, which makes the beam of light play back and forth, but of course the motion is greatly magnified. In this way a perfect record is made of the message in dots and dashes, which are translated into the corresponding letters of the alphabet. DETECTING RADIO SPIES