  We propose to calculate the gluon condensate in lattice QCD in an indirect
way by extracting it from the correlator of hadronic currents of heavy quarks.
Moments (derivatives with respect to momentum at vanishing momentum) of the
vector and pseudoscalar correlators are evaluated. The contribution of the
continuum spectrum in addition to the low-lying resonance is observed in
accordance with qualitative expectations. Finite size effects are observed and
shown to be insignificant for heavy quarks and moderate lattices. A practical
definition of the nonperturbatively renormalized heavy quark mass is given.
