At the beginning of the 1800s, one man, working hard, could produce about sixty cans a day; by 1880, machines could pump out fifteen hundred in a day. Surprisingly, getting them open remained a serious impediment much longer. Various cutting devices were patented, but all were difficult to use or nearly lethal if they slipped. The safe, modern manual can opener—the sort with two rolling wheels and a twisting key—dates only from 1925.
