Kilogram conflict resolved at last

For decades, metrologists have strived to retire ‘Le Grand K’ — the platinum and iridium cylinder that for 126 years has defined the kilogram from a high-security vault outside Paris. Now it looks as if they at last have the data needed to replace the cylinder with a definition based on mathematical constants.

Source: Kilogram conflict resolved at last : Nature News & Comment

If they are proved right, in 2018, Le Grand K will join the metre as a museum piece. “We’ll keep it,” says Davis, “but it won’t be defining anything anymore.”