Harmonic Engine, an invention of Edison's, in which the energy of an electric current is used, by means of two small electromagnets, to keep up the vibrations of a large and heavily weighted tuning-fork. The arms of the tuning-fork are connected with two pistons which work a miniature pump, and this may compress air, which, in its turn, can drive sewing-machines or do other light work.
Harmonic Engine
Chambers's Encyclopaedia, Volume 5: Friday to Humanitarians, p. 561
Source scan(s): p. 0576