Modern practice of the electric telegraph. A handbook for electricians and operators
Frank L. Pope's 1872 handbook, issued in New York by D. Van Nostrand, taught working telegraph electricians and operators the wiring and upkeep of lines, keys, relays and sounders. The 57 wood-engraved plates are circuit diagrams and apparatus views: lettered terminals, coils drawn as hatched cylinders, dotted and solid connecting wires, batteries and switchboards, useful as schematic line art and diagram lettering.
