Source : Webster's Revised Unabridged Dictionary (1913)

Drosometer \Dro*som"e*ter\, n. [Gr. ? dew + -meter: cf. F.
   drosom['e]tre.] (Meteorol.)
   An instrument for measuring the quantity of dew on the
   surface of a body in the open air. It consists of a balance,
   having a plate at one end to receive the dew, and at the
   other a weight protected from the deposit of dew.