William Petty’s device for “double writing” made it possible, he claimed, that “any man, even at the first sight and handling, may write two resembling copies of the same thing at once.” Petty wrote one of the first-known English claims for patent rights, in his 1648 “Brief Declaration Concerning Double Writing.” “Should I have given it away for nothing?” he asked. “The thing...would have been condemned as of no use, because of no price.”

Since 1840 the Oxford Electric Bell has been ringing in a laboratory at the University of Oxford. Built by a London instrument maker and powered by dry-pile batteries, the bell is said to have rung more than ten billion times. The ring is now barely audible because the charge is so low.