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A Lamp or Valve of three electrodes to Transmissions and receptions for Telephony or Telegraphy without wires whose principle is based on the theory of parallel mirrors with Plate, meshStanding and special bulb, filament, and Air filled or emptied
A Lamp or Valve of three electrodes to Transmissions and receptions for Telephony or Telegraphy without wires whose principle is based on the theory of parallel mirrors with Plate, meshStanding and special bulb, filament, and Air filled or emptied
