based on a fundamental physical process (although there are efforts to
change this) is the kilogram, which was originally defined as the mass
of one liter of water, but is now defined as the mass of the
-International Prototype Kilogram (IPK), a cylinder of platinum-iridium
-kept at the Bureau International des Poids et Mesures in S@`evres,
+international prototype of the kilogram (IPK), a cylinder of platinum-iridium
+kept at the Bureau international des poids et mesures in S@`evres,
France. (There are several copies of the IPK throughout the world.)
The British imperial units, once defined in terms of physical objects,
were redefined in 1963 in terms of SI units. The US customary units,