The Collaborative International Dictionary of English v.0.48:

Teinoscope \Tei"no*scope\, n. [Gr. ? to extend + -scope.]
   (Physics)
   An instrument formed by combining prisms so as to correct the
   chromatic aberration of the light while linear dimensions of
   objects seen through the prisms are increased or diminished;
   -- called also prism telescope. --Sir D. Brewster.
   [1913 Webster]