anaclastic glass

from The Collaborative International Dictionary of English v.0.48
Anaclastic \An`a*clas"tic\, a. [Gr. ? to bend back and break; to
   reflect (light); ? + ? to break.]
   1. (Opt.) Produced by the refraction of light, as seen
      through water; as, anaclastic curves.
      [1913 Webster]

   2. Springing back, as the bottom of an anaclastic glass.
      [1913 Webster]

   {Anaclastic glass}, a glass or phial, shaped like an inverted
      funnel, and with a very thin convex bottom. By sucking out
      a little air, the bottom springs into a concave form with
      a smart crack; and by breathing or blowing gently into the
      orifice, the bottom, with a like noise, springs into its
      former convex form.
      [1913 Webster]
    

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