Changes

The base unit of mass is the ''gram''. Originally a gram was the mass of one cubic centimeter (see above), then called a ''milliliter'', of [[water]]. The Lagrange committee fashioned an artifact exactly one thousand times as heavy as this--the volume, in short, of one liter of water--and stored this permanently at Sèvres.

The base unit of mass is the ''gram''. Originally a gram was the mass of one cubic centimeter (see above), then called a ''milliliter'', of [[water]]. The Lagrange committee fashioned an artifact exactly one thousand times as heavy as this--the volume, in short, of one liter of water--and stored this permanently at Sèvres.

[[Joseph Lagrange|Lagrange]]'s committee also proposed a unit of mass caled the ''grave'', to be equal to one thousand grams. But the [[French Revolution|Revolutionary]] government rejected this name as sounding too much like the [[German]] word ''graf'', translated as ''comte'' or [[count]] in French. Therefore, the artifact at Sèvres would be called a kilogram instead--and that artifact has that name to this day.

[[Joseph Lagrange|Lagrange]]'s committee also proposed a unit of mass called the ''grave'', to be equal to one thousand grams. But the [[French Revolution|Revolutionary]] government rejected this name as sounding too much like the [[German]] word ''graf'', translated as ''comte'' or [[count]] in French. Therefore, the artifact at Sèvres would be called a kilogram instead--and that artifact has that name to this day.

Mass never changes. But in addition to the prototype meter changing its length over time, scientists later realized that water has different densities at different [[temperature|temperatures]].

Mass never changes. But in addition to the prototype meter changing its length over time, scientists later realized that water has different densities at different [[temperature|temperatures]].