Source : Webster's Revised Unabridged Dictionary (1913)

Drakestone \Drake"stone\, n.
   A flat stone so thrown along the surface of water as to skip
   from point to point before it sinks; also, the sport of so
   throwing stones; -- sometimes called {ducks and drakes}.

         Internal earthquakes, that, not content with one throe,
         run along spasmodically, like boys playing at what is
         called drakestone.                       --De Quincey.

Source : WordNet®

ducks and drakes
     n : a game in which a flat stone is bounced along the surface of
         calm water