The Collaborative International Dictionary
Whitehead torpedo \White"head` tor*pe"do\, or Whitehead \White"head`\, n. A form of self-propelling torpedo.
Wikipedia
The Whitehead torpedo was the first self-propelled or "locomotive" torpedo ever developed. It was perfected in 1866 by Robert Whitehead from a design conceived by Giovanni Luppis of the Austro-Hungarian Navy. It was driven by a three-cylinder compressed air engine invented designed and made by Peter Brotherhood. Many naval services procured the Whitehead torpedo during the 1870s, including the US Navy. This early torpedo proved itself in combat during the Russo-Turkish War when, on January 16, 1878, the Turkish ship Intibah was sunk by Russian torpedo boats carrying Whiteheads, though this story has been disputed in one book.
The term "torpedo" comes from the Torpedo fish, which is a type of ray that delivers an electric shock to stun its prey.