The Collaborative International Dictionary of English v.0.48:

Tellurian \Tel*lu"ri*an\, n.
   1. A dweller on the earth. --De Quincey.
      [1913 Webster]

   2. An instrument for showing the operation of the causes
      which produce the succession of day and night, and the
      changes of the seasons. [Written also tellurion.]
      [1913 Webster]