  Recent theoretical advances show that the temperature of a system in
equilibriumcan be measured from static snapshots of its constituents'
instantaneous configurations, withoutregard to their dynamics. We report the
first measurements of the configurational temperature in an experimental
system. In particular, we introduce a hierarchy of hyperconfigurational
temperature definitions, which we use to analyze monolayers of
charge-stabilized colloidal spheres. Equality of the hyperconfigurational and
bulk thermodynamic temperatures provides previously lacking thermodynamic
self-consistency checks for the measured colloidal pair potentials, and thereby
casts new light on anomalous like-charge colloidal attractions induced by
geometric confinement.
