Source : Webster's Revised Unabridged Dictionary (1913)

Ferranti phenomenon \Fer*ran"ti phe*nom"e*non\ (Elec.)
   An increase in the ratio of transformation of an alternating
   current converter, accompanied by other changes in electrical
   conditions, occurring when the secondary of the converter is
   connected with a condenser of moderate capacity; -- so called
   because first observed in connection with the Ferranti cables
   in London.