Peter Durand patented the tin can in England in 1810, and for decades nobody sold a tool to open one. People used what they had: a knife, a bayonet, and by one account the advice was to cut round the top with a chisel and hammer. The first real can openers came in the 1850s, Robert Yeates’s in England in 1855 and Ezra Warner’s in America in 1858, nearly half a century late. It is easy to make a joke of that, but the delay probably wasn’t stupidity. The early cans were thick, made to survive ships and campaigns, and nothing small opens a thick can. An opener only made sense once cans got thinner, and they could only get thinner once people trusted them. The opener couldn’t come first. It had to wait for the can to stop being built against everything, including the person who bought it.