Where a new invention promises to be useful, it ought to be tried

I never did anything worth doing by accident; nor did any of my inventions come by accident; they came by work

among the most fascinating of human social or economic inventions.

Human subtlety will never devise an invention more beautiful, more simple or more direct than does nature because in her inventions nothing is lacking, and nothing is superfluous.

An amazing invention - but who would ever want to use one?

I invented the cordless extension cord.