The idea of voting by push button, with electrical technology used to total the votes, dates back to the 19th century, when Frank Wood of Boston was granted a patent on a direct-recording electrical voting machine. (Thomas Edison's electrical voting system patent is sometimes cited in this regard, but it was intended for tallying roll-call votes in legislative chambers; as such, it is more like an audience response system.) The idea of electrical voting was pursued with much more vigor in the 20th century. Numerous patents were filed in the 1960s, many of them by AVM Corporation (the former Automatic Voting Machine Corporation), the company that had a near monopoly on mechanical voting machine at the time.