  We calculate the matrix elements of the gluonic contributions to the
energy-momentum tensor for a pion of mass 600 < Mpi < 1100 MeV in quenched
lattice QCD. We find that gluons contribute (37 +/- 8 +/- 12)% of the pion's
light cone momentum. The bare matrix elements corresponding to the trace
anomaly contribution to the pion mass are also obtained. The discretizations of
the energy-momentum tensor we use have other promising applications, ranging
from calculating the origin of hadron spin to QCD thermodynamics.
