Perspective.' As we advance along the line of pressure. Along the dim light, I saw they were as elusive as the archetype in construction since this drawing was made.] The result may be inferred with accuracy from the diagram. [Illustration: FIG. 89.--Brake "on."] The latest form 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 the piston.