Keys to the New Jersey lab where Thomas Edison invented the phonograph and some of the lightbulbs that he perfected have sold for more than $US60,000 ($A80,400) at auction.
The keys sold for $US10,625 at an auction run by Heritage Auctions in Dallas. A bulb created by a German inventor who claimed to have invented the incandescent lightbulb before Edison did was sold for $US23,750, while a set of five Edison bulbs used in a court case sold for $US30,000.
Tags on some of the keys list the doors that they opened, including Edison's 1876 lab that became known as the "invention factory." Another key says "motor shed," and a third "shop."
