There are two famous anecdotes told concerning Michael Faraday (English scientist, 1791-1867) and the usefulness of scientific discoveries.
They appear in various forms in the works of the nineteenth- and twentieth-century writers on scientific subjects. Both are told usually in relation to Faraday’s discoveries in the field of electro-magnetism. The usual form of the stories is that some dignitary or public official, usually the Prime Minister himself, visited Faraday at the Royal Institution and, on being given a demonstration of the phenomenon of induced currents, inquired: “What good is it?” One of the stories has it that Faraday replied: “What good is a new-born baby?” The other has it that he replied: “Soon you will be able to tax it.”
Source: http://adsabs.harvard.edu/abs/1946Natur.157..196C