Trevelyan rocker

Trevelyan rocker

[trə′vel·yən ‚räk·ər]
(physics)
A prismatic metal block having one edge grooved to form two ridges; it vibrates when heated and placed on the grooved edge, providing a simple example of heat-maintained vibrations.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.