The Collaborative International Dictionary of English v.0.48:

Hertzian \Hertz"i*an\, a.
   Of or pert. to the German physicist Heinrich Hertz.
   [Webster 1913 Suppl.]

   Hertzian telegraphy, telegraphy by means of the Hertzian
      waves; wireless telegraphy.

   H. waves, electric waves; -- so called because Hertz was
      the first to investigate them systematically. His
      apparatus consisted essentially in an oscillator for
      producing the waves, and a resonator for detecting them.
      The waves were found to have the same velocity as light,
      and to undergo reflection, refraction, and polarization.
      [Webster 1913 Suppl.]